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NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
Reciprocating or Piston compressors
Reciprocating or Piston compressors are the most common machines
available on the market. They are positive displacement compressors and can
be found in ranges from fractional to very high horsepowers.
Positive displacement air compressors work by filling an
air chamber with air and then reducing the chamber’s volume (Reciprocating,
Rotary Screw and Rotary Sliding Vane are all positive displacement compressors).
Reciprocating compressors work in a very similar manner as
does as internal combustion engine but basically in a reverse process. They
have cylinders, pistons, crankshafts, valves and housing blocks.
Rotary Screw Compressors
Rotary Screw Compressors work on the principle of air filling
the void between two helical mated screws and their housing.
As the two helical screws are turned, the volume is reduced
resulting in an increase of air pressure. Most rotary screw compressors inject
oil into the bearing and compression area. The reasons are for cooling, lubrication
and creating a seal between screws and the housing wall to reduce internal
leakage. After the compression cycle, the oil and air must be separated before
the air can be used by the air system.
Rotary Sliding Vane Compressors
Rotary Sliding Vane Compressors like Reciprocating and Rotary
Screw compressors are positive displacement compressors.
The compressor pump consists primarily of a rotor, stator,
and 8 blades. The slotted rotor is eccentrically arranged within the stator
providing a crescent shaped swept area between the intake and exhaust ports.
As the rotor turns a single revolution, compression is achieved as the volume
goes from a maximum at the intake ports to a minimum at the exhaust port.
The vanes are forced outward from within the rotor slots
and held against the stator wall by rotational acceleration. Oil is injected
into the air intake and along the stator walls to cool the air, lubricate
the bearings and vanes, and provide a seal between the vanes and the stator
wall.
After the compression cycle, the oil and air must be separated
before the air can be transferred to the air system.
Centrifugal Compressors
Centrifugal
Compressors are not positive displacement compressors like the Reciprocating,
Screw or Vane Compressors. They use very high speed spinning impellers (up
to 60,000 rpm) to accelerate the air then diffuser to decelerate the air.
This
process, called dynamic compression, uses velocity to cause an increase in
pressure. In most Centrifugal compressors, there are several of these impeller/diffuser
combinations. Typically, these machines have intercoolers between each stage
to cool the air as well as remove 100% of the condensate to avoid impeller
damage due to erosion.
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
If you
are looking for an air
compressor, you have come to the right place. At your supplier
we have the air compressor that fits your needs. From gas powered
to oil-less and everything in between you have the air compressor
that is right for you.
This
page will briefly talk about a few of the different air compressor types.
A two-stage
air compressor is normally used in industrial, commercial and automotive applications
where a reliable source is critical. A two-stage air compressor compresses
to a higher pressure than single stage air compressor.
This
allows the air compressor to store more air for future usage. The efficiency
in a two-stage air
compressor in much higher that in a single stage air compressor.
A two-stage air compressor produces more cubic feet of air per horsepower
that a single stage air compressor which results in lower operating costs.
Also
with a two-stage air compressor less heat is generated which reduces the wear
and results in a longer life for you air compressor.
Another
type of air
compressor is portable electric air compressors. With a portable
electric air compressor, you can plug-in anywhere for a convenient alternative
in areas where gas fumes are unacceptable.
Whether
on the construction site or in the shop for power air tools such as framing,
roofing, trim and finish nailers, an electric air compressor makes a great
choice
If you
are interested in purchasing an air compressor, you may also want to look
into an air compressor pressure switch.
Two-stage
and portable electric air compressors are only two of the many different air
compressor types. In addition to our air compressor offerings
There
are many other industrial supplies as well. From a whole house fan to simple
green cleaner or a chain
hoist, A supplier has the industrial supplies you are looking for.
To learn
more about the air
compressor selection from your supplier, or to browse through all
the other industrial supplies we offer, please explore the your supplier online
store today by choosing a link on this page.
Rotary-Vane-Reciprocating-Screw
What
is the difference between these various types of compressors?
What
is the difference between the miniature 12 VDC mini-piston type compressor
you can purchase at your local tire store and a 40 HP rotary screw compressor?
Obviously,
there are giant differences in appearance and size, but the difference
that is really important to the compressed air user is the capacity
that is offered by these various types of compressors.
One
of these two will over deliver substantially if all you need a compressor
for is to blow up a basketball, a bicycle tire, or perhaps an air mattress.
The
discharge rate of a 40 HP compressor would quickly over inflate these items
with unfortunate results. The other, plugged into the power outlet in your
automobile, would not be the logical choice to provide air to your shop.
Yes,
the 12 VDC unit
plugged into your car's power supply can give you 120 PSI air
(depending on the brand of course) just like the 40 HP compressor can, but
with flow levels such that they are only suitable for low flow applications.
If you
tried to use this type of air compressor for a high-demand application, the
compressor could never catch up (compressed air outflow would always exceed
the compressor's ability to compress it) and it would never reach cut out
pressure to allow it to shut down.
Since
these small compressors have a limited duty
cycle it would run at full capacity until it self-destructed; and,
you would never be able to get any work done. A few seconds with your air
tools and the miniature receiver
would be emptied, and thereafter there would never be enough air
flow at the pressure you required for common industrial tasks to get any work
done.
Compressor capacity!
It’s
critical to your operation. All compressors do the same thing. They “gather’
free air, and compress it up to the pressure limit that is specified by the
unit.
Therefore,
you’ll select the type of compressor that delivers the capacity you need,
both in terms of pressure and the flow of compressed air at the pressure your
application requires.
Reciprocating (piston)
air compressors are
the 'work-horse' compressors with which you'll likely be most familiar. You'll
see them at the corner garage, on the shelves at the hardware stores, in residential
garages, many home basements, darn near everywhere, and their uses are numerous
too.
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
Careful
though. Reciprocating compressors often
have the lowest up-front cost, but the highest operating cost! If you're planning
on using a lot of air in your shop or in your home, a different style of compressor
may give you better value over the long haul.
Here's
a link to more information on the reciprocating
type air compressors. Vane compressors use "air-tool"
type technology to compress air. These compressors are used in a variety of
applications.
See
information on vane
compressors through this link. The Rotary Screw compressor manufacturers
state that their technology is the right choice for many industrial applications.
Many
times you'll need compressed air at a site where there aren't any air mains,
and where the common plant electrical supply is not available to run the compressor
motor. That being the case, you'll want to look at this page, that details
information about portable
air compressors. And for the hobbyist or professional spray artist,
please check out this link for information about air
brush compressors .
Portable air compressors
Portable air compressors
vary by size and power level, and there are a few different models available
from which to choose depending on the tools you will use.
Be sure to check
the power requirements of your tools to ensure that you purchase a model that
has sufficient power to run your strongest tool. Regardless of the compressor
you purchase, it is always very important to follow
the safety precautions including safety goggles, protective clothing and proper
footwear.
Portable
rotary screw compressors are one of the more commonly used compressors. They
range from 65 to 1,600 cubic feet per minute, with pressure ratings ranging
from 100 to 350 PSI.
As discussed
above, the compressor you need depends on your tools and the required power
level. Contractors often use 185 CFM because they are able to power two tools
simultaneously. One benefit to this compressor is its suitability for both
the lighter and heavy duty jobs.
The
truck mounted compressor is an oil less air compressor and can be mounted
in the bed or under the hood of a truck. These compressors are excellent space
savers, a great advantage for those with limited space available.
Their
power source is from the engine of the truck, which allows them to be a low-maintenance
compressor. However, one disadvantage is that the truck must be running to
provide the compressor the power it needs. Finally, the deck-mounted compressor
is mounted in the bed of the truck but can be removed and left at the job
site. This compressor does not rely on the truck for power since it has its
own engine.
However,
it does require fuel to power the engine, unlike the truck-mounted compressor,
which runs from the truck. The engine also requires regular maintenance.As you see, the
power source of compressors varies with some powered electronically and others
requiring fuel.
With either type,
though, the air is stored in the holding tank and the tools are to be attached
with a hose. A valve regulates the pressure which is measured by a gauge.
Quincy and Husky are two
of the major brands of compressors. Quincy’s rotary screw
compressors are very durable, reliable and quiet with its power level varying
from 10 to 350 horsepower.
Quincy’s available air
compressors range in size from the smaller tank models to the larger, stationary
styles. Husky’s line of small air compressors are generally made for home
and personal use. The 1.75 gallon tank compressor has 135 PSI power has an oil
free pump for easy maintenance and is easy to transport with its telescope
handle.
This model of Husky
compressors is good for running tools such as nailing guns, for example, and
is also useful for insulation purposes.
Husky’s four gallon
model has 125 PSI power and is a
good choice for running small tools, spraying and even inflating tires and
other recreational items. The four-gallon model is a compressor for homeowners.
Equipment, which
produces, compressed air from ambient air. Compressed air is often a source
of power and motion for packaging equipment.
Compressor
equipment or compressors are used to compress ambient air and give the air
a higher pressure. Compressors can employ different methods to compress ambient
air. A reciprocating air compressor uses reciprocating pistons and valves
to compress the air.
A centrifugal
compressor uses two close tolerance centrifugal turbines to create compressed
air. A screw type compressor uses twin rotating interlock screws with a cavity
between the two screws, which is progressively decreasing in volume.
Most
industrial type air compressors will produce compressed air pressurized to
approximately 100 pounds per square inch (psi). Most packaging machines utilize
compressed air pressurized to 60 to 80 pounds per square inch (psi). (Because
of air pressure regulators attached to most machines, a 100-psi air feed from
a compressor will working for an 80-psi machine.
Compressed air is used in conjunction with pneumatic actuators also called
air cylinders. Air cylinders are designed with a small metal rod with a diaphragm
at one end. An air cylinder can be used as a linear actuator because the metal
rod extends beyond the cylinder and the use of compressed air can turn into
actual motion.
General Information
There
are many different types of Air Compressor Equipment, and Frain can help you
find the right Air Compressor machine to meet your needs. We have Centrifical
Air Compressor Equipment, Reciprocating Air Compressor Equipment, and Screw
Air Compressor Equipment.
Reciprocating compressors - In
these machines, also known as piston-driven compressors, pistons compress
the air in a cylinder and force it into a high-pressure storage tank. Piston-driven
machines are the oldest and most affordable type of air compressor, and are
most commonly found in portable applications or home workshops.
Rotary screw air compressors - Instead
of using pistons, rotary screw compressors use twin screws, like two oversized
drill bits next to each other, to force air up into higher pressures. Until
recently, rotary screw compressors were considerably more expensive than reciprocating
models - now, prices are becoming more and more competitive.
Both
types are available in two-stage models that compress the air a second time
to allow for increased pressure and air flow.
An important
way to decide between these two is to consider whether your application is
continuous use or intermittent. A nail gun, firing a burst of air every few
seconds, is an intermittent tool, while a spray painter is used continuously.
If your application calls for continuous use, you'll want a rotary compressor.
That's
due to the rated "duty cycle:" the amount of time each hour that
a compressor is able to work. A duty cycle of 75% means the air compressor
needs to rest for 15 minutes out of every hour to cool down. Rotary compressors
have a duty cycle of 100%, thanks to fewer moving parts and robust oil cooling
systems. In contrast, reciprocating compressors are designed to run only part
of the time.
A third major type is the centrifugal compressor.
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
These
high-end compressors are essentially turbine engines: they use rotating blades
to create high pressure. They are almost exclusively used in power plants
and huge industrial applications, simply because they begin to become economically
competitive at a scale well beyond that of most users.
 
Breaking it Down
Every compressed-air system
begins with a compressor - the source of air flow for all the downstream equipment
and processes. The main parameters of any air compressor are capacity, pressure,
horsepower, and duty cycle.
It is important to remember
that capacity does the work; pressure affects the rate at which work is done.
Adjusting an air compressor's discharge pressure does not change the compressor's
capacity - even though many people seem to believe it will.
There are a number of
basic air compressor designs - and variations of them - on the market today.
They all fall into two general categories: positive displacement and dynamic.
Although the operating
specifications for two different types of air compressors may be very similar
on the surface, other installation and performance factors can make one design
superior to the other in a real-world application. Let's review some of the
basic designs and terminology.
Reciprocating
compressors
Reciprocating compressors
are positive-displacement units that trap a charge of air and then physically
reduce the space that confines it, causing its pressure to increase.
Reciprocating units, commonly
called piston compressors, use a piston, cylinder, and valve arrangement.
Their operation is very similar to the familiar internal-combustion engine,
but they simply trap and compress the air without adding fuel to explode it.
Note that whenever air
is compressed, heat is generated. Proper cooling of the internal parts of
any air compressor is a critical part of its design.
There are three basic
selection decisions that must be made about reciprocating compressors:
• single- or double-acting
operation,
• single- or multi-stage
configuration, and
• air or water cooling.
In a single-acting piston
compressor, the piston only compresses air in one direction of its stroke.
In a double-acting model,
the piston compresses air with both directions of its stroke. Obviously, because
both strokes perform work, a double-acting compressor is more efficient (in
moving a volume of air per input hp) than a comparable-size single-acting
unit.
A single-stage unit compresses
air from inlet to discharge pressure in one operation. A multi-stage unit
compresses from inlet to discharge pressure in two or more operations - generally
passing the air through an intercooler to remove some of the heat of compression
between each stage.
This saves power and keeps
the compressor's internal operating temperatures lower.
In air-cooled compressors,
ambient air circulates around the compressor cylinders and finned heads to
provide cooling. Heat transfers through the metal to the air. Air-cooled units
are generally designed for 50% to 75% duty cycles, depending on the particular
units and their application.
In water-cooled compressors,
integral water jackets surround the cylinders and heads. Heat transfers through
the metal to the water - more effectively than through metal to air. Thus,
water-cooled reciprocating units reduce internal temperatures more efficiently
than comparable air-cooled units.
Most air-compressor manufacturers
promote the two-stage compressor as the optimum machine for producing 100-psi
class air - the base pressure level in most industrial plants - providing
the best efficiency per dollar cost with adequate reliability of internal
working parts.
For a reciprocating compressor
to be categorized as continuous duty, it is generally agreed that it must
be double acting and water cooled. Double-acting, water-cooled reciprocating
compressors are offered in a variety of styles that combine efficient air
compression with durability and reliability. However, they also are heavy
and bulky, making them relatively expensive to install.
They generally have more-significant
unbalanced forces, which combines with their size to require a special foundation
and support.
When they meet selection
criteria such as capacity, weight, size, and price,
single- and two-stage single-acting reciprocating units are a good choice
- particularly in the 50- to 150-psig pressure ranges. (Three-stage reciprocating
units are offered, but generally are used for pressures above 250 psig.)
Oil-cooled
rotary-screw compressors
The rotary-screw compressor
is another positive-displacement machine. In an analogy with the reciprocating
compressor, Figure 1, the male rotor is like a piston, pushing air along the
female rotor, which is like the cylinder. The sealing strips are like piston
rings, and air is compressed against the stationary end plate, which is like
the bottom of the cylinder.
This design has been around
for about 50 years. However, until the mid 1970s, it was considered suitable
only for engine-driven portables and small-horsepower electric-motor units
because of low efficiency (the ratio of compressed-air delivery to power cost).
In the 1970s, development
began on two-stage rotary screw compressors for pressures up to 250 psi. Rotor-profile
development during the 1970s, 1980s, and early 1990s has led the oil-cooled
rotary-screw design to become the significant choice in electric-motor-driven,
lubricated, industrial air compressors, particularly in sizes from 20 to 300
hp.
Then, a significant breakthrough
in air-end design occurred. The introduction of the unsymmetrical profile
resulted in an efficiency improvement of approximately 15%. This improvement
was significant enough to make the oil-cooled rotary-screw compressor competitive
in the larger-horsepower sizes for continuous duty. It has almost the same
efficiency as the single-stage double-acting units and smaller centrifugal
compressors.
Two-stage rotary-screw
compressors can approach and sometimes equal the full-load performance of
two-stage reciprocating units in 100-psig class service.
Today, two-stage oil-cooled
rotary-screw compressors are frequently used in the 150- to 400-psia pressure
range. They also are used for 100-psi service with significant power savings.
Two stages offer advantages associated with lower compression ratio per stage.
Reduced pressure differential
across the rotors minimizes blow-by and significantly reduces thrust-bearing
loads. (Obviously two-stage units require two air ends, which increase the
initial cost.)
The unique characteristic
of this compressor is that it is cooled by oil. Oil injected into 
the air stream absorbs
the heat of compression while it is being generated.
The heated oil then is
taken to an air- or water-cooled heat exchanger for cooling. Because the cooling
takes place right inside the compressor, the working parts are never subjected
to extreme operating temperatures. The cooling oil never is cracked nor burnt.
No matter what the load
on the compressor is, there are no hot spots inside the airend. The resulting
absence of wear produces trouble-free service and high efficiency.
In other words, oil-cooled
rotary-screw compressors can run at full load and full pressure -twenty-four
hours a day, seven days a week. This compressor's useful life in operating
hours and its maintenance cost per hour will be the same as under any other
load condition.
Continuous
duty
The availability of continuous-duty
air-cooled compressors (particularly in large sizes) offers a great deal of
flexibility for installing them.
Such compressors can be
mounted on any surface that will support their static weight. In many facilities,
great savings also are available in piping cost, compared to other types of
systems.
These compressors lend
themselves to either the central- or departmental-compressor system concept.
Units are available with electric motor and engine drives - on bases, on skids,
on wheels, etc.
Compared to other types
of continuous-duty air compressors, oil-cooled rotary-screw compressors offer
a number of advantages:
• Oil cooling holds internal
temperatures to an optimum level. As a result, discharge air is relatively
cool -no more than about 180° F higher than ambient.
• Discharge air is clean
- free from burned oil or carbon.
• The rotary design lends
itself to higher speeds, particularly in the larger sizes. Consequently, larger
flow capacity is available from compressors with physically smaller envelopes
- providing significant savings on floor space and foundation requirements.
• Because of their compact
size and inherent quiet-running characteristics, it is relatively easy to
suppress noise. Electric-motor-driven models are commercially available rated
from 75 to 85 dB at one meter per the CAGI Pneurop Test Code.
• Most models have fewer
moving parts, and those parts run under more ideal conditions - resulting
in lower temperatures and less vibration.
• Fewer parts make it easier
to stock them for the rotary designs, and the machines are easier to work
on.
In summary, oil-cooled rotary-screw
compressors offer users a continuous-duty source of compressed air in a neat,
compact package that has low initial cost, maximum flexibility of installation,
and easy maintenance.
Non-lubricated
rotary screw and lobe
In addition to the non-lubricated
reciprocating compressors that have become so common over the years, there
are several versions of non-lubricated positive-displacement lobe or screw
rotary compressors.
These units are referred to
as clearance-type compressors because the internal parts do not contact each
other, so they require no lubrication in the compression chamber. Cooling
is accomplished through the cylinder walls via water jackets.
The lobes or screws do not
drive one another either; they are driven by some type of gear arrangement
instead. This drive system also acts as a timing gear to maintain the rotor
or lobe profile relationship accurately. Lubricant for the drive train must
be confined to the bearing and gear area - and not allowed to get into the
compression chamber.
In this basic design, there
is a constant leakage rate for any fixed set of conditions. The critical internal
clearances are between end covers and the rotor, between the rotor lobes,
and between the rotor OD and the cylinder ID.
These gaps, combined with no
injected oil to help with sealing, are the main reasons why two stages are
required for these units to produce acceptable efficiencies in 100-psi class
applications.
Because these are rotary units,
they enjoy all the advantages of rotaries over similar-sized non-lubricated
reciprocating units:
• compact size,
• smooth delivery of cool
air,
• ease of installation,
and
• simple (but critical)
maintenance
They also have some disadvantages,
depending on the specific type of compressor and its duty cycle:
• more sensitive to dirty
inlet air,
• lower efficiency - resulting
in higher power cost, and
• any repair work is more
sophisticated and requires specialized training, which the user may not have
nor want to have. This means repair work will probably have to be performed
by the distributor or the manufacturer.
Sliding-vane rotary compressors
Oil-cooled sliding-vane compressors,
Figure 2, operate as other positive-displacement compressors do by trapping
a charge of intake air - in this case, between the vanes. As the eccentric
rotor turns, the vanes are forced into the rotor slots, shrinking the size
of the cell holding the trapped air.
The air is compressed to full
discharge pressure when it reaches the outlet port. The heat of compression
is removed by cooling oil sprayed right into the air while it is being compressed.
The same oil helps with sealing the vane tips.
For decades, oil-cooled, sliding-vane
rotary compressors have been popular for continuous-duty applications. Their
design has a number of unique characteristics:
• light weight - yet continuous
rating,
• integrated and compact
configuration,
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
• efficient production
of compressed air at relatively low rotary speeds,
• smooth operation with
little vibration,
• extremely quiet operation,
• coolest possible discharge
air, and
• few wearing parts, making
the machine easy and economical to repair.
However, the oil-cooled rotary-vane
design in its single-stage configuration is limited in capacity. Bending stress
applied to the vanes is the problem.
The speed, size, and weight
of the vanes must be limited for the machine to be durable. Because of this,
oil-cooled rotary-vane compressors generally are applied only in a size range
between 2 and 100 hp.
Lubricated
or lube-free?
Two fundamental groups of compressor
types are lubricated and lube-free. Lubricated compressors use oil to reduce
friction between moving parts.
As a result, some oil is entrained
in the air being compressed. The entrained oil must be removed from or tolerated
by the downstream system.
Lube-free compressors use no
oil in the airend, and thus add no oil to the compressed air they produce.
Power and
efficiency
Brake horsepower is the input
power required at the compressor input shaft for a specific speed, capacity,
and pressure condition.
Motor or engine horsepower
is the nominal rating of the prime mover.
The service factor is the additional
power built into an electric motor above its nominal rating - expressed as
percent. Within the service factor, the brake horsepower driving an air compressor
can be higher than the motor's nominal horsepower.
The power efficiency of a compressor
is the ratio of the air delivered by the compressor and its input electrical
requirements. Efficiency usually is expressed as brake horsepower per 100
cfm of delivered air.
Water-cooled
rotary screws
Another version of oil-free
rotary-screw compressors is a single-stage design that uses water injection
to cool and seal the rotors during compression.
The bearings and drive gears
are lubricated with oil and sealed from the compression chamber. These units
serve a selected market and are a special design. In some applications, care
must be taken to avoid the build-up of bacteria in the water. 
Approximately
70 percent of all manufacturers have a compressed air system. These systems
power a variety of equipment, including machine tools, material handling and
separation equipment, and spray painting equipment.
Energy
audits conducted by the U. S. Department of Energy (DOE) suggest that over
50 percent of compressed air systems at small to medium sized industrial facilities
have energy efficiency opportunities with low implementation costs.
Compressed
air is one of the most expensive uses of energy in a manufacturing plant.
About eight horsepower of electricity is used to generate one horsepower of
compressed air. Calculating the cost of compressed air can help you justify
system improvements that increase energy efficiency.
The
links below will help you calculate the cost of compressed air use, understand
your compressed air system and identify easy to implement energy efficiency
strategies for compressed air systems.
Air
Compressor Energy-Saving Tips Approximately 70 percent of all manufacturers
have a compressed air system. This fact sheet about air compressors will help
you calculate their operating cost, understand your system and identify easy
to implement energy efficiency strategies.
AirMaster+
Software This compressed air system assessment and analysis software package
helps maximize the efficiency and performance of compressed air systems through
improved operations and maintenance practices. Find under “Tool Box.”
Assessing
Compressed Air Needs Carefully assessing your company’s compressed air needs
will ensure that the system is configured correctly. Compressed air needs
include air quality, quantity and level of pressure necessary for the end
uses in your plant.
Compressed
Air System Audits Comprehensive compressed air system audits are performed
by several different types of firms and receiving one can help your company
improve efficiency and productivity. An audit should contain an assessment
of both air supply and usage and the interaction between the supply and demand.
Compressed
Air System Controls Compressed air system controls are one of the most important
determinants of overall system energy efficiency.
Compressed
Air System Economics Compressed air system costs can really add up, but improving
the performance of the system can save your company a significant amount of
money.
Compressed
Air System Leaks Leaks can be a major cause of wasted energy in a compressed
air system. Proactive leak detection and repair can be accomplished by implementing
a leak protection program.
Energy
in the Air Over the life of an air compressor, energy costs will be five to
10 times the compressor's purchase cost. Use the tips in this article to ensure
that your air compressors are running as efficiently as possible.
Heat
Recovery with Compressed Air Systems As a way to save energy, heat from the
electrical energy used by compressed air systems can be recovered for various
uses throughout the shop like industrial process heating.
Inappropriate
Uses of Compressed Air Compressed air can be the most expensive form of energy
in a plant and it is important to consider more cost-effective, alternative
forms of power before using it.
Kaeser
Compressors—Achieve Significant Savings through Improved Energy Management
Overall operating power costs are impacted significantly by the air compressor
package.
To help
minimize energy wasted at the air compressor site use energy efficient components,
state-of-the-art control systems, and look for equipment that maintains low
pressure drop over its entire service life.
Listening
for Leaks MnTAP staff can help you find compressed air and steam trap leaks
using an ultrasonic leak detector.
Maintenance
of CA Systems for Peak Performance Periodic maintenance can help your compressed
air system operate at peak efficiency and minimize unscheduled downtime.
Packaged
Compressor Efficiency Ratings The Compressed Air and Gas Institute (CAGI)
has developed performance testing standards to help with the daunting task
of evaluating and comparing air compressor capacities and efficiencies.
Pressure
Drop and Controlling System Pressure Minimizing pressure drop is helpful to
avoid excessive energy consumption and requires a systems approach in design
and maintenance of the system. Controlling system pressure is another opportunity
to achieve significant savings.
Proven
Opportunities at the Component Level Analysis of the individual components
of compressed air systems can help enhance the efficiency of your overall
system.
Top
Compressed Air Energy Saving Options Compressed air assessments at metal casters,
pulp and paper mill, and mines reveal that facilities have common opportunities
for energy efficiency improvements: storage, sequencing and removing inappropriate
uses.
U.S.
Department of Energy's (DOE) Office of Industrial Technologies (OIT) BestPractices
DOE OIT BestPractices works with industry to identify plant-wide opportunities
for energy savings and process efficiency through implementing new technologies
and systems improvements.
BestPractices
provides an assortment of tools and resources to help industrial end users
achieve efficiency improvements and related cost savings.
Industrial
Case Studies
Compressed
Air Project Improves Efficiency and Production at Harland Publishing Facility
The John H. Harland Corporation reconfigured a new type of printing machine
that uses less compressed air and requires a lower pressure to operate effectively.
The project allowed Harland to avoid spending more than $500,000 for additional
compressors that would have led to over $200,000 per year in energy and maintenance
costs.
The
project’s implementation improved the performance of the new printing machines,
which has led to better product quality and reduced production cycle time.
Compressed
Air System Upgrade Results in Substantial Energy Savings BWX Technologies
completed a retrofit project on the compressed air system.
The
replacement of antiquated compressors and dryers, along with the implementation
of a more sophisticated control strategy, significantly improved the efficiency
of the compressed air system and led to important savings in energy and maintenance
costs and reduced the need for wastewater treatment. Annual energy savings
totaled $264,000, or 4.2 million kWh, with a payback of less than 2 years.
Using
Compressed Air Evaluate your compressed air use. K-Bar uses compressed air
to blow powder paint off its racking.
A MnTAP
site visit helped World Aerospace Corporation determine that closed loop cooling
was not economically feasible for the size of its compressor.
Water
Heater Company Saves $160,000 Annually with Compressed Air System Improvements
The American Water Heater Company (AWHC) improved its compressed air system
that serves its manufacturing plant.
This
enabled the system to support the plant’s production processes more effectively,
significantly improving product quality and allowing for greater production.
Annual energy savings totaled $160,000 with a payback of 17 months.
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
This section contains a general discussion
of the essential elements that typically make up a working air compressor
system and items crucial for proper installation and operation.
It is intended to introduce the principal
topics that should be considered in an air compressor project. An expanded
technical discussion of these topics can be found in the section on Air
Compressors. The general components of a compressed air system
are illustrated schematically in the figure below.
A compressed air installation may consist
of one large or multiple smaller compressors of sufficient size to meet the
overall air requirement.
Either motors or engines may be used as
the driver. Hence, a prospective owner has a choice of electricity, gas, or
oil for the energy input. The optimum installation is one which has the lowest
combination of installation cost, maintenance cost, and operating cost.
The Conditioning/Drying stage is required
to remove any particulate, water, oil or other contaminants that could damage
or adversely affect equipment using compressed air.
Pressure control is necessary to assure
that proper air pressure is maintained in the system, while the end use loads
of a system determine the installed capacity required (equipment diversity
and system leaks must also be taken into account). Ventilation and heat rejection
assure that the unit will run properly and not overheat.
The system also should have enough flexibility
to adapt to the range of needs and load conditions of the site. The necessary
information on load profiles and duration can be obtained from various sources,
including interviewing plant personnel, reviewing plant logs, and examining
air compressor unit operating conditions
A typical compressed air profile is presented
in the figure below. From this profile, it can be seen that the peak load
is slightly in excess of 1,500 SCFM, the minimum load is 1,100 SCFM, and the
"average" load can be roughly estimated at 1,300 SCFM.
This information is useful in determining
maximum, minimum, and redundancy requirements for proper sizing of equipment,
as well as determining the appropriate equipment technology to be selected.
For any type of compressor used, the unit
should be mounted on a level solid foundation so that no strain is imposed
on the base. Space should be provided on all sides for normal maintenance
and proper air circulation. Compressors should be installed in clean, cool,
dry locations which are well ventilated. Areas that have dirt, vapors, and
volatile fumes should be avoided as they may clog the intake filter and valves.
If this is impractical, a remote air intake should be used.
The compressed air distribution piping should
be of sufficient size to keep the pressure drop through it to a minimum. The
main air line should never be smaller than the compressor outlet size.
All piping should be sloped to an accessible
drain point, and branch or outlet lines should be connected to the top of
the main so that moisture will not enter the outlet.
Many accessories exist for use in compressed
air systems. Some are relatively common and will be found in almost every
installation, while others are special purpose devices and may be found under
certain circumstances. Locations and application of devices that provide the
"conditioning/drying" system function can be found in the following
schematic. Brief descriptions of these devices and their system functions
follow the figure.
Aftercooler: Assists in the
removal of moisture in compressed air. Aftercoolers remove moisture by lowering
of the air temperature and may be of the air-cooled or water-cooled type.
Air Line Lubricator: Designed to inject oil mist into the compressed air system for the lubrication
of air tools and equipment.
Automatic Water Valve:
A valve designed to automatically control water flow to water-cooled compressors.
Belt Guard: A mandatory feature
for all belt-driven compressor units where the flywheel and motor pulley belts
are exposed.
Discharge Line Filter:
Designed to trap foreign matter in the compressed air stream that may be harmful
to pneumatic tools and equipment.
Dryers: Designed to minimize
all moisture in compressed air systems. Many different types of dryers exist.
Filter: Assures foreign
matter does not enter into the compressed air system. Many types are available,
and should be selected based upon manufacturer’s recommendations.
Manual and Magnetic Starters: Provide thermal overload protection for motors and should
be used as recommended by local electrical codes.
Moisture Separator: Designed to trap and expel oil or condensed moisture in a compressed
air system. Expulsion of moisture may be manual or automatic.
Pressure control devices that are typically
found in a compressed air system include the following:
Pressure Reducing Valve: An adjustable device that regulates a higher (and somewhat
variable) initial line pressure to a lower constant secondary pressure.
Pressure Relief Valve:
An adjustable device that relieves pressure beyond a specified upper limit
and re-closes upon return to normal operating conditions.
Receiver: A vessel in which
gas is stored under pressure as a source of pneumatic fluid power; may be
classified as either "wet" or "dry" and refers to the
position of the receiver relative to the dryer(s).
When examining the feasibility of installing
additional or replacing existing air compressors, it is necessary to document
the existing equipment. A Preliminary Data Entry Formdownload
PDF will prove helpful in obtaining this information when performing
field investigations. Not all sections of the form will be relevant to all
projects, but the form allows for recording manufacturer, model no., capacity,
and other technical performance information for all system elements.
A Dryer can remove moisture from compressed
air to a certain degree of dryness and this is referred to as pressure dew
point.
Different
types of dryers can achieve different dew points and, for the most part, the
drier air needs to be, the more expensive it is to dry. (The obvious exception
to this is the Atlas Copco MD Series heat of compression dryer that uses the
energy of a 100 watt light bulb, yet achieves incredibly low pressure dew
points.)
Gulf Atlantic Equipment Company is
proud to offer the finest dryers on Earth, properly applied and competitively
priced.
• Refrigerated Dryers condense the moisture
out of the air and drain it away as liquid. They are limited to about 35°
F because the water would freeze if it got any colder.
• Desiccant Dryers adsorb the moisture
in the compressed air and remove it while still suspended as vapor. They are
typically applied at about -40° F, but can get to -100 and below.
• Membrane Dryers use permeability to separate
the moisture from the air and can also achieve low dew points.
And
the list goes on. The selection is made on personal preference, the dryness
required, and cost, which should include operating and electrical or utility
costs
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
The
obvious advantage of fitting an inverter drive to a screw compressor is energy
saving - this can regularly be as much as 30% of the absorbed power.
Secondly
as the machine is almost permanently under load conditions there is less wear
and tear on consumables such as inlet valve seals, drive coupling inserts
etc. There can be disadvantages such as over-heating of both the motor and
compressor air-end during extended low rpm operation.
A fixed
speed compressor which is converted to be variable speed will only have a
limited speed range with a maximum speed reduction to approximately 50% of
nominal motor speed. Many purpose built variable speed drive compressors will
turn down to as 20% of the maximum speed / compressor capacity.
There
are many other considerations to take into account also - will the air-end
rotors remain efficient at low speed? Slippage back across the rotors increases
dramatically in many units at different rev bands.
I would recommend data-logging your application to see how much air you are
using and how much demand varies before making a decision. It may be more
economical in the long run to buy a purpose built variable speed drive compressor
and keep the GA45 as a back up.
One of the first things some people do before they hit the
trails is air down the tires. It's really easy to do, but what about airing
back up? There are several options for on-board air on the trails.
Here are a few options:
 Bring a portable
air tank with you. Should be good for a few fills, but won't help if you're
gone for a while with no way to air the tank back up.
Carry a small
compressor powered by the lighter jack. It's good for emergencies, but takes
a long time to fill a large tire. Some companies sell portable compressors
that are made to fill up tires fast, but most won't run air tools, and they
are generally over $200.00. But, they are relatively simple to install, and
very little if any fabricating will be required.
Bring a C02 tank.
These are much better than the smaller portable air tanks, and will fill lots
of tires, and run air tools, but you have to get it filled when it gets empty.
And some can cost more than the portable compressors.
Run a compressor
off of the engine. This supplies large amounts of air, is fast enough to run
air tools, and will always work as long as the engine is running.
The compressor is also fairly inexpensive. But, most likely,
a bracket will have to be made to mount the compressor to the engine because
there are so many different accessory and belt configurations available for
GM vehicles.
Out of all these options, I chose to do an engine driven
compressor. The cost, as well as the constant supply of air, were the main
benefits. The most common compressor for this type of setup is the York-style
compressor. It can be found on Ford, Volvo, AMC, IH, and Oldsmobile vehicles
from the late 70's to the early 80's.
You
have any amount of air tools in the garage then you will need a portable air
compressor to run them. Most garage hobby mechanics will choose portables
over a stationary because they can be used in lots of different applications.
A portable unit gives you the option of moving the compressor out the
garage and hooking up a nail gun to work in the house or yard.
Electric
or Gas Powered
They are either powered by an electric motor or a gas engine
for more professional models. The pump puts the compressed air into a storage
tank and then a hose is hooked up to power your air tools.
Most
portable air compressors are oil lubricated pumps. The oil-lubricated models
are quieter and generally last longer than oil free models but will require
you to change the oil periodically. An oil free model is easier to deal
with but will not last as long with prolonged use.
Arrangement
of the Air Tank
Portables generally come in different tank configurations. There are basically
two different styles on the market. Pancake
style modelshave the motor and compressor mounted on top of a
pancake shaped storage tank.
You
will mostly see these units running a nail gun. They are popular for this
application because you can quickly pick one up and move it around. There
is also a twin
stack arrangement of the storage tanks.
These
have two long, narrow tanks mounted next to each other with a wheel
mounted in the middle. Both of these types of models are electric powered
and will run on a 15 amp house circuit.
I would
recommend staying away from anything bigger for you r house because they will
pop your breaker trying to draw too many amps.
How Big of a
Compressor Do You Need?
Choosing the right size is critical to running your air
tools. The most important factor is the storage tank size not horsepower or
air pressure. This is where you have to ignore the slick salesmanship on the
box.
The
larger the capacity of the storage tank the longer you can run your air tool.
Impact wrenches for example use a lot of air to run them and a smaller tank
will quickly run out of air before the pump can refill it. Air volume is really
the limiting factor.
Almost
all air tools require around 90 psi of pressure and all these units will do
that. A nail gun for example only requires about 2.2 CFM to run compared to
angle grinder that needs anywhere from 8 to 30 CFM. This is why a pancake
style is fine for a nail gun but if you are running impact wrenches and air
grinder you will need a larger model.
Currently two different types of engines
are used in air compressor applications: industrial and automotive-derivative.
Industrial engines are typically designed
to operate for longer lifetimes than automotive-derivative. These engines
operate at speeds up to 1,800 RPM.
The time between major overhauls or rebuilds
on this type of engine is in excess of 20,000 hours of operation. Industrial
engines are designed so that all the parts that experience wear can be replaced.
These major overhauls allow the life of an industrial engine to be extended
"indefinitely." However, industrial engines are more expensive than
automotive-derivative.
Automotive-derivative engines are rated
for higher speed (more than 3,000 RPM) operation and are modified versions
of those used in automobiles and other mobile applications.
These engines are less costly than the industrial
grade engines, and therefore can decrease the capital cost of a project. Other
benefits of these engines are that they are somewhat smaller and lighter in
weight. The cost and availability of parts is generally better than industrial
engines.
However, the life of these engines is significantly
shorter. Automotive-derivative engines are generally replaced at the end of
their useful life, and are not rebuilt like the industrial engines.
Therefore, the reduced installed cost of
this type of engine is countered by the increased operating costs of replacing
the engine at regular intervals. Also to be factored in is the downtime to
overhaul an industrial engine (2 weeks) versus replacing an auto-derivative
engine (2 days).
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
Analysis to assist in deciding between engine
types should consider the following:
- Life cycle
cost comparison (first cost; operating, repair, and maintenance costs; and
replacement cost)
- Duty-cycle
(operating hours)
- Customer reliability
requirements
Overview
Gas engine technologies are available for
a variety of applications that require a prime mover. A prime mover simply
converts one form of energy (gas or electricity) to mechanical work (turning
a shaft) for use in a process. Thus, a prime mover can be an electric motor
or a gas engine.
Gas engines perform the same function as
an electric motor, they provide shaft work for process applications. Shaft
work includes turning a shaft to operate a pump, a compressor, a grinder,
a crusher or a generator.
In many applications an electric motor can
be replaced with a gas engine. The primary advantages of using a gas engine
are:
- Significant
operating cost reductions and
- Fuel diversity
and
- Better part
load efficiency than an electric motor
With gas engine applications, customers
will be able to achieve a flexibility for processes that weren’t an option
just a short while ago. They will be able to "shape" their energy
profile, which will allow them to negotiate much more attractive energy prices
than if they were committed to a single technology/energy source.
Gas engines can help customers operate more
efficiently, more cost effectively and they can offer customers fuel diversity
for their facilities.
Natural Gas Engine basics
When identifying an opportunity for, and
selling a customer on a Natural Gas Engine application you should be familiar
with the technology.
This includes knowing not only the benefits
of installing a Natural Gas Engine but being able to inform the customer of
some facts about the technology and about the maintenance considerations.
A Natural Gas Engine is similar to the engine
in your car except that instead of using liquid gasoline as a fuel source,
natural gas is used as the fuel source.
There are two types of Natural Gas Engine
technologies available for customers, spark ignited Natural Gas Engines and
compression ignition Natural Gas Engines.
Spark ignited
- Use a spark
plug to ignite fuel (just like a car engine)
- Are the most
common type of Natural Gas Engine available. They are used in a wide variety
of Natural Gas Engine applications. This includes Natural Gas
- Engines for
vehicles, water pumping systems, compressors and chillers.
- Used in dedicated
Natural Gas Engines or natural gas/ propane blend engines
- Can use gas
with a lower Btu content (i.e., sewage plant digester gas)
- Has a good
compression ratio (about 9.4:1)
- Wide choice
of sizes (49 Hp to 2600 Hp)
Compression ignition
- Commonly seen
in heavy-duty transportation applications such as trash haulers.
- Uses a small
charge of diesel fuel to ignite cylinder charge
- Designed for
heavy duty, high load applications
- Extremely long
life
- Has a higher
compression ratio (15:1)
Other technical information
Low speed Natural Gas Engines (< 1400
RPM):
- Typically are
larger engines than a high speed engine
- Longer time
between maintenance intervals (rebuilds)
- Higher first
cost due to greater bulk of the equipment
High speed Natural Gas Engines (> 1400
RPM):
- Lower first
cost than a low speed model
- Shorter time
between maintenance intervals (rebuilds)
- Usually turbocharged
Note about Underwriters Laboratories: UL is the trusted source across the globe for product compliance. Benefiting a range of customers - from manufacturers and retailers to consumers and regulating bodies - they’ve tested products for public safety for more than a century.
Automotive derivative Natural Gas Engine:
- Very low first
cost
- Maintenance,
operation and engine life similar to an automobile engine
- When engine
is at end of service life, simply replace with a new unit
Rich burn engines:
Engines that use a rich air-fuel ratio.
These are common in Southern California because their emissions
are very easy to control.
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
Lean burn engines:
Engines that use a lean air-fuel ratio.
These engines are not as common as rich burn engines because they require
a 
more sophisticated emission control system.
Other considerations for Natural Gas Engine
systems:
Air Quality – Natural Gas engines
may need to be permitted and may have emissions limits. It is important to
be aware of this when marketing a gas engine system to customers.
Maintenance – Natural Gas Engines
do require maintenance, just like a car engine. However, with a maintenance
schedule that is strictly adhered to, a Natural Gas Engine will give years
of reliable service.
Noise – Natural Gas Engines
are louder than an electric motor and may require sound attenuation.
Ventilation – combustion processes
require air to take place. Natural Gas Engines need an adequate supply of
air to operate. If a central plant is being built or designed, this fact should
be considered in the early stages.
How a Gas Engine Works
A gas engine converts the chemical energy
of natural gas to mechanical work. The rate of energy conversion in a gas
engine is as follows:
he energy balance above illustrates why
heat recovery adds significantly to engine system efficiency. Usable heat
can be recovered from both the jacket water and exhaust. Heat from the jacket
water can be used to make hot water, heat from the exhaust can be used to
make hot water or low pressure steam.
Air/Fuel system:
Natural gas engines can be naturally aspirated
or 
turbocharged. In naturally aspirated engines
air is drawn into the engine at atmospheric pressure.
Turbocharged engines use the exhaust to
drive a small turbofan that compresses the intake air. The turbofan compresses
the air fuel mixture so more molecules are squeezed into the cylinder.
When the mixture is ignited, more energy
is released. Thus, a turbocharged engine will provide more shaft work out
than a naturally aspirated engine of the same size.
Schematic of a Turbocharger
Turbochargers usually have a heat exchanger
(an intercooler or after cooler) located after the compressor fan to remove
heat from the compressed air. By cooling the compressed air, the density is
increased, so oxygen content for a given volume of air is increased and more
fuel can be burned.
Turbocharger with Intercooler
The advantage of a turbocharged engine is
that about 35% more work can be done by a turbocharged engine as compared
to a naturally aspirated engine of the same size.
Gas engine with turbocharger
For more information:
Gas Engine Maintenance
Gas engines require regular maintenance
just like the engine in your automobile. In fact, the maintenance activities
are similar to the maintenance activities you do on your car. Customers with
Natural Gas Engine systems can sign a maintenance agreement with their vendor
at a reasonable cost.
A good rule of thumb for annualized maintenance
costs is $.011 (one and one tenth cent) per horsepower-hour. This amount will
vary depending on how the engine is used but is a very good ball park figure
to use to determine annualized maintenance costs.
Example: If you have a 200
Hp engine that operates for 2500 hours a year the annualized maintenance costs
would be:
200 Hp x 2500 hrs/yr.
x $.011/Hp-hr. = $5500
Maintenance is scheduled by the run hours
on the engine. A good guide for gas engine maintenance is in the table below:
Daily:
- Check fluid
levels and bring them to proper level (if needed)
- Visually inspect
engine for leaks and/or loose belts and hoses
250 hours:
- Visual inspection
of hoses and belts
750 hours:
- Oil and filter
(air and oil) change
- Adjust valves
- Check ignition
timing
- Visually check
spark plugs
- Check/replace
fuel filter (the filter cleans moisture and dust from fuel)
- Clean Crankcase
breather
1500 hours:
- Check/clean/(or
replace as necessary) spark plugs
- Check gas pressure
to carburetor (Service Tech can provide this service)
- Check carburetor
adjustment for excess O2 (Service Tech can provide this service)
6000 hours:
- Exchange/rebuild
water pump and water pump idler pulley assembly
- Inspect Turbocharger
and aftercooler (do maintenance per Mfr.’s recommendation)
- Check cylinder
compression (compression should be uniform across cylinders)
Top end overhaul:
Remove cylinder heads and do a valve job
and top end inspection at around 11,000 hours (+/-) for both low speed and
high speed engines. (Customer should follow Mfr.'s recommendations!)
Note: as valves are cycled in the combustion
process they may not seal properly due to wear on the valve and seat surfaces.
A valve job refinishes the surface of the valve and the valve seat so that
it seals properly when the valve is closed.
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
Major overhaul:
Top and bottom end rebuilds (valves, cylinder
rings, crankshaft and camshaft bearings, oil seals)
(at around 24,000 hours for high speed engines; around 34,000 hours for low
speed engines)
Other maintenance
Engine oil analysis:
Chemical / physical properties of oil –
evaluating oil integrity, checking for water or coolant in the oil and checking
for entrained solids. Oil properties can give a very good idea of how the
engine is performing and may alert customer to a problem before it becomes
a major problem. Customer should check with Mfr. about this service.
Note: regarding maintenance,
to convert maintenance hours to something your customer would understand,
simply multiply the hours by 50 or 60 to get a mileage equivalent.
For example, the Mfr. recommends changing
the water pump at 6000 hours of operation.
If you drove your car for 6000 hours at
50 mph, you would accumulate approximately 300,000 miles on your odometer!
This gives the customer a better feel for the maintenance requirements of
a gas engine.
Air Quality for Gas Engines:
Natural Gas engines may require Air Quality
permitting if they are installed. The exception to the permitting requirement
is for Agricultural customers (farmers) who use them for Agricultural water
pumping for crops or to supply water to livestock.
Most Air Quality Districts have similar
emissions limits. For the South Coast Air Quality Management District the
limits are:
- Natural Gas
engines of 50 Hp or greater require permitting. (customers in RECLAIM may
need to buy emissions offsets to operate an engine)
- Emission requirements
for gas engines are (per Rule 1110.2)
NOx - .15 grams per
- Hp-hr
CO - .6 grams
per Hp-hr
VOC - .15 grams per Hp-hr
- Gas engines
1000 Hp or greater require Continuous Emissions Monitoring (CEM)
- Agricultural
engines are exempt from air quality regulations
Emission controls:
Gas engine emissions are very easy to control.
For rich burn engines, a non-selective catalyst with an air-fuel ratio controller
can be used to keep the emissions below the limits. A non-selective catalyst
is similar to the catalytic converter on your car.
Lean burn engines require a selective catalytic
reduction system, typically ammonia injection, to clean emissions. Selective
catalytic reduction systems are more costly to buy, operate and maintain.
Gas engine Features and Benefits:
- Gas engines
offer very favorable operating cost advantages
- Gas engine
systems are not schedule sensitive. Gas rates have no excessive "demand"
charges. Rates are declining block type rates, "the more you use, the
less you pay".
- Gas engines
have variable performance characteristics that match energy use with system
demands. Gas engines have very good part load performance.
- Gas engines
offer fuel diversity. Hybrid systems give the customer a choice of fuels.
Hybrid systems also can help a customer negotiate better energy prices from
suppliers since they can shape their "energy profile" any way
they want.
- You can also
use Propane as a back up fuel in the event of Natural Gas supply shortages.
- Customers can
store gas for fuel supply redundancy.
- The Gas Company
can help with permitting of new gas engine technologies.
- Customers with
gas engine or hybrid systems will not feel the effects of brown outs or
energy price spikes as much as other businesses. They will have options!
- Gas is delivered
via The Gas Company’s system. There is no need to wait for fuel deliveries
as is necessary for propane systems. There are no fuel tanks, which mean
no fire code regulatory hurdles or insurance worries. Customers only pay
for the natural gas they use, they don’t have to pay for fuel deliveries
prior to use so they don’t tie up capital in a tank.
- Gas engine
manufacturers and dealers can provide turn key maintenance packages for
customers allowing them to concentrate on their business.
On the next several links we will review
benefits of gas engines for specific applications.
Conclusion
Natural Gas Engines offer customers many
options for their business and also offer many benefits to customers that
choose to make a Gas Engine an integral part of their process.
Superior part-load performance: Gas engines operate much more efficiently at part load than
electric motors. The energy consumption will closely follow the load on a
gas engine. Electric motors have very, very poor part load efficiency. They
consume about 95 - 98% of full load power even at low loads.
More stable energy prices: Gas engines often have better operating economics than an electric motor.
This is particularly true during warm weather when heavy demand charge penalties
kick in.
Gas engines are high-tech: New gas engine packages have advanced microprocessor controls that continuously
monitor engine conditions and alert operators of any items that may need attention.
They can be used in systems that have centralized controls.
Higher potential total efficiency: Gas engine systems can incorporate heat recovery into
the process that raises the overall efficiency to well over 50%. Traditional
electric plants have an efficiency of 30%. By including heat recovery in a
process savings are achieved on the shaft work and in the recovered heat.
Natural gas has an Octane rating of 130.
Octane rating is a measure of the antiknock property of a fuel, it can be
thought of as resistance to detonation. High compression engines require high-octane
fuels to operate properly and natural gas fits the bill.
Natural gas is free from liquid hydrocarbons.
Liquid hydrocarbons, such as Gasoline, Ethanol and Diesel, wash the lubricant
from the cylinder walls and dilute engine lubricants.
They also leave gum and varnish deposits.
Natural gas does not dilute lubricants or leave gum and varnish deposits.
Some customers have experienced longer times between oil and filter changes
because Natural Gas burns so clean.
Natural gas burns cooler and cleaner than
other liquid fuels such as diesel and propane. There is less contamination
of the lubricating oil with carbon and nitrates, which helps keep the equipment
operating at top performance.
NOTE: HEAVY DUTY INDUSTRIAL
AIR COMPRESSORS, MEDICAL AIR COMPRESSORS, AND PORTABLE DENTAL
AIR COMPRESSORS COME IN BOTH TYPES-AS ELECTRIC AIR COMPRESSORS
AND GAS POWERED AIR COMPRESSORS. SITES WITH AIR COMPRESSORS
FOR SALE (DISCOUNT) AND AIR COMPRESSOR RENTALS ALSO HAVE PARTS,
AND CHEAP AIR COMPRESSOR ACCESSORIES; I.E., ELECTRIC MOTOR,
INTAKE FILTER, FITTINGS, HOSE, SWITCH, REGULATOR, BELT, AND
TANKS. LOOK FOR AN AIR COMPRESSOR KIT FOR HIGHEST VALUE AND
LOW PRICE. CAN BE SENT AT DISCOUNT PRICES. YOU CAN BUY NOW
OR RENT. EQUIPMENT IS ON SALE WITH A PRICE COST OF LOW DOLLARS
AND CENTS. REFUND IS OFTEN IN CASH IF NOT SATISFIED. IF YOU
DECIDE TO BUILD YOUR OWN (DIY) YOU CAN OFTEN UTILIZE LEFTOVERS
FROM FACTORY SECONDS, SURPLUS , DISCONTINUED MERCHANDISE,
GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT, RETAIL CLOSEOUTS, ITEMS
FROM FACTORY REJECTS, OUT OF BUSINESS SALES & FACTORY
CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS! WHEN BUYING
ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN EXPRESS, AND
VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST AND SECOND
QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR AT CLOSEOUT
AND DISTRESSED SALES. WE DO NOT BROKER OR BUY THESE ITEMS
FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL FOR USED EQUIPMENT,
REPOSSESSIONS, JUNK, INSURANCE SALVAGE OR FREIGHT SALVAGE.
DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE OF GENERAL SUPPLY
FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN, BUY NOW, BUY
NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER. SAVE $ $
$ $ $ $ $ $ $ $.
|
|
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