Air lubricator

AIR LUBRICATOR

1. What is an Air Lubricator?

• Function: The function of an air lubricator is to add a controlled amount of lubricant with air to ensure proper lubrication of internal moving parts of pneumatic components.

• The lubricator adds the lubrication oil in the form of a fine mist to reduce the friction and wear of the moving parts of pneumatic components such as valves, packings used in air cylinders, etc.

• At the same time excessive lubrication is also undesirable. Excessive lubrication may result (i) malfunction components, (ii) increased environmental problems, and (iii) seizing of components after prolonged downtime.

2. What is the best type of Lubricant for a Pneumatic System ?

1. Generally a good-quality, light-grade spindle oil is used in pneumatic systems.

2. Sometimes, a mixture of 50% kerosene and 50% SAE 30 oil is also used as lubricant.

3. Construction and Operation ́

The construction and operation of a typical force-feed type air lubricator is illustrated in Fig.11.10(a). Its operation is similar to the principle of simple carburetor used in the petrol engines to obtain air-fuel mixture.

As the air to be lubricated enters into the inlet pipe, the venturi ring located in the pipe increases its velocity of low. It causes a local reduction in the upper chamber. This pressure differential between upper and lower chambers causes suction of lubrication oil from the oil reservoir to the upper chamber. Now the oil in the form of mist is sprayed in the air stream and the air-oil mixture is obtained. This air-oil mixture is forced to swirl as it leaves the central cylinder causing more oil particles to be spread out of the air stream. The amount of oil dropping into the upper chamber can be controlled by a needle valve.

4. Graphic Symbol

Fig.11.10(b) shows the graphic symbol for an air lubricator.