The concept of twin screw compressor and twin head is different. The former is screw compressor classification, the latter is (refrigeration) system classification.
Twin screw compressor: generally known as the screw compressor, generally refers to the twin-screw compressor.
In the compressor body, parallel equipped with a pair of spiral rotors meshing with each other. Generally, the rotor with convex teeth outside the pitch circle is called male rotor or male screw. The rotor with concave teeth in pitch circle is called female rotor or female rotor. Generally, the positive rotor is connected with the prime mover, and the male rotor drives the female rotor to roll. The final pair of bearings on the rotor complete the axial positioning and accept the axial force in the compressor. The cylindrical roller bearings at both ends of the rotor make the rotor complete the radial positioning and accept the radial force in the compressor. At both ends of the compressor body, do not leave the orifice with certain shape and size. One is for suction, which is called air inlet; the other is for exhaust, which is called exhaust port.
Screw compressor is divided into single screw compressor and twin-screw compressor. The twin-screw compressor has a pair of rotors with spiral teeth which mesh with each other and rotate in the opposite direction.
Double head: in engineering, the power machine (such as motor) is called the head, and the double head is the double power drive.

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