what is service air compressor and what is instrument air compressor? what is the diffrence between them?

Answer 1

*It is the name given to the compressor depending upon the application of air, I mean compressed air is used for actuating the solenoid valve,control valve,moving hydraulic cylinder,cleaning of column,flushing of columns(distillation).
*Same type of compressor can be used for both the applications.
*Compressed air is generally passing through after cooler,moisture trap,heater and alumina air dryer(adsortion type) so that its dew point is controlled in the range of -50 degree centigrades.I mean to say allmost no moisture.This is essential for all the air actuated instruments.
Same air is distributed to instrument header and service air header.
Since the control systems are very vital for any chemical,pharmaceutical industries ,seperation of instrument air and process air is essential.
Due to any service air operation ,instrument should not get disturbed,so the seperate lines are required.
Service air again use for operating air motors using FRL unit as air motors required lubrication.
*There are two main types of compressed air systems: oil-free and lubricated. One design will be chosen over the other, depending on purification and industry requirements. Air purification requirements include general purity, instrument quality, breathing air, medical air, pharmaceutical, and clean dry air.

Oil-Free Systems: Applications that cannot tolerate a lubricant require an oil-free system. It is critical to remove unwanted oil aerosols and vapors from compressed air, not just moisture. These aerosols and vapors are found in ambient air and can be generated by the compressor. This oil ends up degraded and oxidized by the heat of compression. Once heated, the oil can carbonize and form a solid, varnish-like substance on downstream equipment, causing valves and air tools to malfunction. If the oil is mixed with water, it forms a sludge that can gum up components of the air line. Downstream from the compressor, an air receiver stabilizes system pressure, serves as a demand reservoir, and holds some moisture. Downstream from the receiver, an air dryer, which will provide the correct pressure dew point, traps the remaining moisture. If either of these fail, there is still a coalescing filter after the dryer to provide protection. A dry receiver can also be installed after the coalescing filter to stabilize pressure and serve as a reservoir for times of high demand.

Lubricated Systems: These types of systems use a lubricant to alleviate friction between moving parts. In rotary screw compressors, the lubricant also seals clearances and removes heat of compression. The viscosity of the lubricant used depends largely on the operating ambient temperature range. It must offer adequate lubrication for bearings and rotors at operating temperature. In addition, it must have a pour point low enough to provide fluidity at low starting temperature. A modern, lubricated rotary screw compressor and high-efficiency purification system can produce compressed air with very high purity. These systems are very similar to the oil-free system, consisting of a wet receiver, an air dryer, and a coalescing filter. There is, however, a charcoal filter between the coalescing filter and the dry receiver that removes any leftover oil vapors.

Answer 2

Air Compressor Wiki

Answer 3

That is not terminology I am familiar with. There are compressors that generate compressed air for running equipment and others that generate compressed air for injection into a chemical process or external discharge like blowing chips off of a lathe.
Some of these require filters, dryers and conditioners to process the air for different reasons.

Dentists use special air compressors to run their instruments as well.

Answer 4

Likely the required quality of air (moisture, oil, and particulate, etc.) may be different for sensitive equipment as opposed to general purpose applications. Either separate air supplies (air compressors or bottled gas) must be used or service air must be conditioned to meet the specifications for sensitive components such as instrumentation and control devices. For example, if control air is supplied to a valve actuator exposed to freezing temperatures, moisture could freeze in supply lines affecting operation. Certain pneumatic devices may receive their lubrication from the air supply.

Answer 5

The compressor is the same for both systems, but the produced compressed air is simply fed to the two systems after cooling and having the free water separated out in a Knock-out drum and drained away.
The air is then divided to pass to both systems each having its own pressure control instrumentation.
The air to general service use receives no further treatment.
The instrument air however, is passed through one of two Silica-gel adsorbers (drying) units to remove all traces of moisture. This is to prevent any moisture entering sensitive, small diameter piping and equipment involved in the instrumentation of the process plant it is feeding thereby protecting them from corrosion and blockage.
(The 2nd drier is on standby and, when a drier becomes saturated, the units are switched over and the saturated unit is regenerated by passing a heated portion of the dry air through it to atmosphere, to vaporise the moisture out.).

Answer 6

Tony is correct. Service air is used in a plant for use with tools and equipment. Instrument air is used to control procces control equipment, such as valves. If you only had the one instrument air system and no service air you could possibly deplete/starve your control instruments and your plant would shut down.

Answer 7

service air is the air system used in maintenance like cleaning

instrument air is the air system used in operating kneumatic instrument valve. the design involved more safety features

Answer 8

SERVICE AIR COMPRESSORS ARE OIL LUBRICATED WHILE INSTRUMENT AIR COMPRESSORS ARE DRY TYPE . CONSTRUCTION, OTHERWISE ARE SIMILAR.