One of the most frequently overlooked energy efficiency, environmental
improvement, and cost reduction opportunities is in the area of process vacuum. Most
major industries use vacuum to improve heat transfer effectiveness, boost
evaporator performance, aid filtering and drying operations, and produce superior
melted metals.
Vacuum is produced by vacuum pumps, blowers, and steam jet ejectors. In certain situations, a combination of these devices produces the most efficient and cost effective design.
There are several vacuum pumps design alternatives:
liquid ring, reciprocating, rotary lobe or piston, and sliding vane designs. Steam
jet ejectors are also commonly selected due to their lower first cost and
simplicity of design. However, steam jets have much higher operating costs.
All vacuum producing devices are actually compressors discharging at or near atmospheric pressures. Their compression to that discharge pressure forces them to draw a vacuum at their inlets.
