Capacity Control :
All screw compressors used in the package series are fitted with a continuous capacity control with a range of 25 - 100%.
The position of the control slide is indicated by the position transducer and reported on compressor control device.
The hydraulic slide adjustment is controlled by two solenoid valves, which are contained in one block and mounted direct on the screw compressor.
During start-up of the screw compressor package, a differential pressure is created between the suction and discharge side of the machine, which enables oil flow though, system. Parameters are controlled through ODP1 and ODP2 on the microprocessor controller.
One of the start-up requirements for the compressor drive motor is that the control slide of the compressor be in its MIN end position. The MIN end position is adjusted via a strain-spring during compressor stand still.
If the control slide of the compressor is not in its MIN end position, the command to reduce capacity is given and the control slide is driven to its MIN end position.
The solenoid valve block can be used for all compressors with fixed Vi at all operating conditions.
The solenoid valves are pulsed by the control system.
Starcore screw Compressor Package uses all valves and flow controls from Danfoss / Hansen or equivalent. The Package Controller is customized through CARYSOFT programme for system operation and control. The Logic Controller is SCADA enabled capable of getting hooked to any BMS system. |