Halward

Exhaust filters are used to remove impurities from air drawn through a ventilator in a closed system.
Exhaust filters are an essential component of industrial air pollution or emission control systems.
The basic construction of these exhaust filters is a filter panel, or a physical barrier made of spun fibers that attract and trap pollutants, which is held within a frame and placed in ductwork that an air stream is drawn through. Engine and industrial filters, however, use more complex procedures, though filter panels are often an additional pre or final means of filtration.

Vacuum pumps are dry positive-displacement pumps. A crankshaft-driven connecting rod (4) moves the diaphragm (1) that is tensioned between the head cover (2) and the housing (3). The space between the head cover and the diaphragm forms the suction chamber (5). Diaphragm pumps require inlet valves and outlet valves (6) to achieve targeted gas displacement. Pressure-controlled shutter valves made of elastomer materials are used as valves. Since the suction chamber is hermetically sealed off from the drive by the diaphragm, the pump medium can neither be contaminated by oil nor can aggressive media corrode the mechanics. The dead volume between the outlet valve and the suction chamber results in a restricted compression ratio which means that with just one pumping stage it is only possible to achieve an ultimate pressure of approximately 70 hPa. Connecting multiple pumping stages in series makes it possible to attain an ultimate pressure of 0.5 hPa. Lower pressures cannot be achieved, as 

 

Vacuum pumps are dry positive-displacement pumps. A crankshaft-driven connecting rod (4) moves the diaphragm (1) that is tensioned between the head cover (2) and the housing (3). The space between the head cover and the diaphragm forms the suction chamber (5). Diaphragm pumps require inlet valves and outlet valves (6) to achieve targeted gas displacement. Pressure-controlled shutter valves made of elastomer materials are used as valves. Since the suction chamber is hermetically sealed off from the drive by the diaphragm, the pump medium can neither be contaminated by oil nor can aggressive media corrode the mechanics. The dead volume between the outlet valve and the suction chamber results in a restricted compression ratio which means that with just one pumping stage it is only possible to achieve an ultimate pressure of approximately 70 hPa. Connecting multiple pumping stages in series makes it possible to attain an ultimate pressure of 0.5 hPa. Lower pressures cannot be achieved, as 

The single stage vacuum pump is the multi-purpose devices which can be used not only as vacuum pumps, but can also be easily used in the compressor duty with small installation modifications.