The smallest 3-5kW water-injected CRC

VERT Rotors releases a set of test data for the small 3-5kW water-injected compressor VERT.80.W. It runs at 3,000 r/min at 3kW or at 6,000 r/min at 5.5kW.

The VERT.80 design is based on VERT’s patented CRC technology and (a) produces compressed air without oil contamination, and (c) is 40% more compact than comparable oil-injected screw compressors. VERT.80.W is an ultra-compact “clean air” rotary machine operating with minimal vibration. The tests show:

  • 8 bar(g)
  • Flow rate 200 l/min at 3kW, 420 l/min at 5.5kW
  • 40% more compact system than oil-injected twin-screw machines
  • 50% more compact system than comparable oil-free scroll systems

It is more compact than the oil-injected competition because water has a better cooling capacity and the elements of the cooling system are much smaller. For the same reason the air does not need after-cooling, which makes the system simpler and cheaper to produce.

Water-injection was introduced by VERT Rotors because the Conical Rotary Compressors are produced from non-corrosive materials and the design was ready for water. VERT.80.W is a rotary machine that operates with low vibration, which is the main difference with the comparable reciprocating compressors.

With a growing demand for oil-free air from the electronics, life sciences, and food & drinks industries, water-injected screw compressors offer a more efficient alternative to the dry-running reciprocating compressors. Such ultra-compact machines as the 3-5kW water-injected VERT.80.W were not available on the market until today.

To produce oil-free air, “there are two alternative technologies available – adiabatic compression (dry-screw technology) and isothermal compression (water-injected screw technology). However, the former has disadvantages: heat generated in compression is transferred to the resultant compressed air – leading to loss of efficiency in generating the correct volumes of air needed, and consequently less air delivery per kW used. They also involve higher capital outlay and increased running costs. On the other hand, water-injected screw compressors have superior cooling capability that removes the heat efficiently at source, creating a constant temperature in the compression element, thus allowing more air per kW to be generated and electricity costs to be cut.”[Maintenance & Engineering Magazine, Sept/Oct 2014]