Basics of Pneumatics and Pneumatic Systems Nov14

Basics of Pneumatics and Pneumatic Systems...

Basics of Pneumatics and Pneumatic Systems Pneumatics has long since played an important role as a technology in the performance of mechanical work. It is also being used in the development of automation solutions.  Pneumatic systems are similar to hydraulic systems but in these systems compressed air is used in place of hydraulic fluid. A pneumatic system is a system that uses compressed air to transmit and control energy. Pneumatic systems are used extensively in various industries.  Most pneumatic systems rely on a constant supply of compressed air to make them work. This is provided by an air compressor. The compressor sucks in air from the atmosphere and stores it in a high pressure tank called a receiver. This compressed air is then supplied to the system through a series of pipes and valves. The word ‘Pneuma’ means air. Pneumatics is all about using compressed air to do the work. Compressed air is the air from the atmosphere which is reduced in volume by compression thus increasing its pressure. It is used as a working medium normally at a pressure of 6 kg/sq mm to 8 kg/sq mm. For using pneumatic systems, maximum force up to 50 kN can be developed. Actuation of the controls can be manual, pneumatic or electrical actuation. Compressed air is mainly used to do work by acting on a piston or vane. This energy is used in many areas of the steel industry. Advantages of pneumatic systems Pneumatic systems are widely used in different industries for the driving of automatic machines. Pneumatic systems have a lot of advantages. High effectiveness – There is an unlimited supply of air in the atmosphere to produce compressed air. Also there is the possibility of easy storage in large volumes. The use of...

Compressed Air System in a Steel Plant...

Compressed Air System in a Steel Plant Compressed air is the air which is kept under a pressure having a value greater than the atmospheric pressure (1.03 kg/sq cm). It is a medium that carries potential energy. Compressed air is a widely used utility in a steel plant. It is an important source of instrument air. Other than instrumentation air which is completely dry and free from contaminants, there are the following three main uses of compressed air in a steel plant. Blast air for blast furnace For the production of oxygen, nitrogen and argon in an air separation plant A utility gas with many uses. Major among it is the operation of pneumatic devices Normally for blast furnace the cold blast air is supplied either by a turbo-blower or an electric blower. In the air separation plant, there are dedicated compressors producing compressed air of the specification needed by the air separation plant for the production of oxygen, nitrogen and argon gases. In case of compressed air being used as a utility gas, steel plants usually have either a centralized compressed air system or/and local compressed air systems. Compressed air is an expensive utility when evaluated on a per unit energy delivered basis. The advantage with the use of compressed air is that it can be easily stored in air receivers and readily available for brief peak demand periods. There are inefficiencies in converting electricity into compressed air as well as line losses in the compressed air distribution. Although the total energy consumption of such systems is normally small, compressed air systems are the most expensive energy in the steel plant due to its very low efficiency. Typical energy efficiency of a compressed air system is around 12 % to 15 %.  Various measures can help...