Compressor Lubricants and Compressor Lubrication - Part 1

Compressor Lubricants and Compressor Lubrication

Cylinder and Packing Oil Recommendations

The following matrix shows recommended oil for a given discharge pressure and type of gas. These lubrication recommendations are general guidelines. If the recommended lubricants or flow rates do not appear to work adequately, flow rates and/or lubricant types may need to be changed. Please contact the lubricant supplier for specific lubricant supplier for specific lubricant recommendations.

MATRIX - Cylinder and Packing Oil Recommendations for Various Gas Stream Components

Base Rate Calculations

There are many different ways to calculate the amount of oil that is injected into the cylinders. Most manufacturers historically have used a specific base amount of oil and factored that by the diameter of the cylinder or piston rod. Other components of the calculated lubrication rate may include piston stroke and speed. The total amount of oil has been specified by a total volume of oil or by the number of drops per minute. B far, the more accurate measure for lubrication is the volume of oil.

Drops per minute only provide the correct amount of oil at a specified temperature. If the temperature is colder or hotter, the size of the drop can change dramatically. This may either inject into the system. The smaller drop of hotter lubricant will not provide the same lubrication as the larger drop of colder lubricant.

A total volume of oil such as pints per day is more accurate because it will inject a consistent amount of oil into the system regardless of the temperature. A base rate set by a number of pints per day per inch of bore diameter is one common calculation method to determine the total amount of oil required by that point. The base rate is determined by:

Base Rate (pints per day) x Bore (inches) = Total pints per day at full rated speed

A second calculation is then needed to determine the cycle time for a given divider block and to modify that rate for reduced speed.
Another calculation method injects one pint per day per 2,000,000 ft2 of cylinder surface area.

(Bore x Stroke x rpm) ÷ 31800 = Pints per day

Again, a second calculation is needed to determine the cycle time for a given divider block.
Once the total pints per day are known for each injection point, the proportion of the total is used to determine the size of distribution block needed. Determining the proportions of the blocks needed is done by using ratios of the required rates and then selecting a block that provides the closest match. Usually a range of 90% to 115% will allow for selection of a block.
Finally, once all the blocks are known, the cycle time can be calculated by the following equation.

Cycle Time = (6 x Sum of all blocks) ÷ Total Quantity of Oil

Energy Efficiency in Air Compressors

Compressed air is a versatile tool used widely throughout industry for a variety of purposes. Unfortunately, running air compressors often uses more energy than any other equipment.

Air compressor efficiency is the ratio of energy input to energy output. Many air compressors may be running at efficiencies as low as 10 percent. Improving compressor efficiency can yield significant savings to your facility.

When talking about the efficiency of air compressors, it is important to remember that the compressor itself is only one part of the system; therefore it is important to look at the whole system when discussing AC efficiency. Compressed air is the product of a system comprised of the air compressor followed by after-coolers, receivers, air dryers, air storage tanks, supply lines and possibly sequencers and multiple compressor units.

The total energy use of a compressor system depends on several factors. The air compressor type, model and size are important factors in the compressor's energy consumption, but the motor power rating, control mechanisms, system design, uses and maintenance are also fundamental in determining the energy consumption of a compressed air system.

SYSTEM DESIGN

Four aspects of system design are crucial to compressor efficiency.

Save for times of need. The first aspect involves choosing a receiver, or storage tank, to fit the needs of the system demand and prevent system pressure from dropping below minimum required pressure during times of peak demand. A drop in pressure will cause end tools to funtion improperly. The common response to the tool malfunction is to increase the system pressure. The energy used in increasing system pressure could have been saved through the use of a properly sized reciever.

Straighten the path. The second aspect of system design is the layout and design of the air delivery system. Narrow delivery lines, looping and sharp bends in the lines can create pressure drops in the system and reduce end use pressure. The common response to this is to increase compressor pressure and use more energy; this could have been avoided through better system design.

Use cooler intake air. A third design aspect that may have a significant impact on air compressor efficiency is the intake air temperature. The energy required to compress cool air is much less than that required to compress warmer air. Reducing the intake temperature by moving the compressor intake outside the building and into a shaded area may drastically lower the energy required for compression.

Single vs. Multiple compressors. In some systems it may be more efficient to use a series of smaller compressors rather than one larger compressor. Additional smaller compressors can be brought on-line, or shut down as needed.

Recover waste heat. Recovered waster heat can be used to preheat process and boiler water, for space heating, and more.

USES

Discourage inapporopriate uses. Because compressing air is one the most expensive sources of mechanical energy in the industrial setting, it is often financially beneficial and more energy efficient to use alternative tools or methods when possible. Some common uses of compressed air that may be accomplished by other means are:

• Personal Cooling


• Cleaning where dry cleanup would be appropriate


• Drying


• Mixing, atomizing and aspirating

• Process cooling


• Moving parts

MAINTENANCE

Fix the leaks. This is the area where the most significant changes can occur. In addition to having a great impact on energy use, improvements here are also often relatively cheap and have immediate results.

The number one source of energy loss in an air compressor system can usually be traced to wasted air. Wasted air is lost through leaks in the system. Although leaks are often very small, significant amounts of air can be lost. The air lost is proportional to the size of the orifice and a function of the air compresor supply pressure. The following graph illustrates the amount of the air lost through differen orifice sizes.

Change the filters. Another important element of the system is filters. Filters are located throughout the system to ensure clean air for end uses. Often these filters are not known of or are simply not checked. Dust, dirt, moisture and grease can clog the filters leading to a pressure drop in the system. This pressure drop is not often seen for what it is and more compression energy is used to compensate for the clogged filters resulting in increased energy use.

Checklist

Source: Hoerbiger India

Posted by Mitul Choksi

What is CFM?

CFM

• This is the usual unit of measure for discharge air from a compressor
• CFM is the acronym for Cubic Feet per Minute. A compressor is said to have so many cubic feet of compressed air per minute (CFM) of flow from it's discharge port.
• When it comes to using compressed air in your plant or home workshop you will want to know how many cubic feet per minute you can expect from the discharge port of your compressor to help determine if that compressor has sufficient compressed air flow to power your air tools or other air-consuming applications.
• To do that you need to know what CFM a particular device or tool will require to function within it's design parameters. The device or tool will require a certain number of CFM at a specific air pressure, to work properly.

A rule of thumg is that 1 HP generates about 4 CFM at the rate of 90 PSI

• This is an industry standard, though it doesn't apply to most compressors under 10 HP. For compressors smaller than 10 HP, you will need to read the specifications for that particular unit to determine their flow and pressure rates or use the "guesstimate" of 2 CFM at 90 PSI per HP of electric motor
• When you've sized all of your applications and totalled up all of the air you're going to need now and for the future expansion you may be undertaking in the future, and you are out searching for the right air compressor, you would divide the number of CFM you need by 4, and that will give you a rough idea of the horsepower rating of the compressor required.

Be Careful. Not all compressor manufacturers rate their compressor output the same way. You might see a compressor showing a discharge rate at what appears to be an acceptable CFM, but on closer inspection find that the figure is predicated on a much lower pressure than you might need.

Discharge rates in CFM at higher pressures are always quite a bit lower than discharge rates at lower pressures, for that same compressor.

Ensure that the unit you select will give you both the CFM you need, and the pressure your equipment demands to work properly for you.

Posted by Mitul Choksi

Additional Safety Instructions for Air Compressors

1. AIR NOZZLE
Never aim an air nozzle directly at yourself or others.
Compressed air can break the skin, or enter the bloodstream
through soft tissue or a cut, and cause a stroke or death.

2. AIR COMPRESSOR STORAGE
DO NOT store the compressor while plugged into power. If a leak develops, the compressor may run continuously, causing overheating and possibly a fire .

3. UNATTENDED TOOLS
DO NOT leave before relieving the tool of air pressure and
disconnecting it from the air hose.

4. AVOID BURNS
DO NOT touch the motor or the air supply pipe,
they will become hot during operation.

5. COMPRESSED AIR USE
Do Not use the compressor for filling breathing or diving tanks.
Compressed air from this compressor cannot be used for pharmaceutical, food or health applications.

6. AIR HOSE
Make sure your air hose has a PSI rating exceeding the
maximum PSI of your compressor, is in good condition, and is long enough to reach your work without stretching. Make sure the air lines and power cord do not come in contact with sharp or abrasive objects.

7. PLASTIC (PVC) PIPE
DO NOT use plastic pipe for high pressure air lines. It could shatter, resulting in serious injury.

8. TANK CORROSION
Drain the tank after each use to prevent corrosion and possible tank rupture. Inspect the tank for unsafe conditions such as rust, pin holes and cracks.NEVER weld or drill holes in an air tank.

9. SAFETY VALVE OR PRESSURE SWITCHES
NEVER adjust safety valve or pressure switch to allow the
compressor to build higher PSI than rated.
Keep safety valve free from paint and other accumulations to
provide safety against over-pressure.


There is danger associated with the use of air compressors. Accidents are frequently caused by lack of familiarity or failure to pay attention. Use this air compressor with respect and caution to lessen the possibility of operator injury. If normal safety precautions are overlooked or ignored, serious personal injury may occur.


For any further details feel free to contact us

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Ahmedabad - 380 009 Gujarat (India)

Phone: 079 - 26589712
Fax: 079 - 26586954
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Check List & Service Schedule for Air Compressor

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For further any queries please feel free to contact us..

Aeroflon Engineers Pvt. Ltd.
B-505, Premium House,
Opp. Gandhi Gram Railway Station,
Ahmedabad - 380 009 Gujarat (India)

Phone: 079 - 26589712
Fax: 079 - 26586954
Email: info@aeroflon.com /aeroflon@vsnl.net /aeroflon@gmail.com
Web: http://www.aeroflon.com/
Our Blog: http://blog.aeroflon.com/

Troubleshooting & Solutions

Aeroflon Engineers Pvt. Ltd.
B-505, Premium House,
Opp. Gandhi Gram Railway Station,
Ahmedabad - 380 009 Gujarat (India)

Phone: 079 - 26589712
Fax: 079 - 26586954
Email: info@aeroflon.com /aeroflon@vsnl.net

aeroflon@gmail.com
Web: http://www.aeroflon.com/
Our Blog: http://blog.aeroflon.com/