Screw compressors designed for non-stop operation combine the advantages of a compact screw compressor with low installation and operating costs and excellent performance, especially in applications that require continuous operation. All functions are controlled via a user-friendly electronic controller. Smaller floor dimensions and an easy installation help solve space problems. The cost savings are tremendous.
The electric motor assembly with compression unit ensures stable power transmission during operation. The motor support system has been designed to prevent loads on rotating parts. The series is equipped with a poly-v belt drive with cast iron pulleys, which ensures the best reliability in all operating conditions and reduces energy losses.
This transmission system also ensures a low noise emission level and perfect alignment of the rotating parts. A simple belt tensioning system allows a precise adjustment of the belt tension.
PRINCIPLES OF SCREW COMPRESSORS DESIGNED FOR NON-STOP OPERATION
• In the initial start-up phase, the electric motor (14) (with “star” power supply) rotates slowly. The solenoid valve is not powered, and therefore the suction valve (3) remains closed. The length of this phase is adjustable.
• During the second phase of the “delta”, the power supply accelerates the motor until it reaches its operating speed. The solenoid valve is powered and the suction valve (4) opens, which allows air to pass through the suction filter (12) and enter the screw element (2). This starts the compression phase.
• The air-oil mixture supplied by the screw element (2) is transported to the separator tank (7).
• The initial amount of oil is mechanically separated from the air and settles to the bottom of the separator tank while air accumulates at the top.
• With the help of pressure, the air is pushed into circulation through the separator filter (11), where the next stage of the air-oil separation is performed, and then the air enters the minimum pressure valve (9). This allows air to pass only when the set pressure point is reached. When this is reached, the air travels through the air cooler (10), where it cools, and then continues its way into the pressure vessel. The oil removed from the air by the separator filter (11) flows through the oil return pipe from the separator to the screw compressor. The amount of oil can be monitored through the sight glass.
• In the model with a dryer, the air passes through the dryer where it dries and cools before entering the pressure vessel.
• If the unit does not have an automatic condensate drain, the condensate that accumulates in the pressure vessel must be drained manually using the condensate drain valve.
• The pressure pushes the oil from the bottom of the separator tank into the thermostatic valve (17). This valve sends oil with a temperature above the reference point to the oil cooler (9), where it cools down. When cooled, the oil is returned to the thermostatic valve (17), where it mixes with the hot oil coming from the separator tank. Here the thermostatic valve checks the oil temperature again. When the (lower) temperature reference point is exceeded, the oil is sent to the oil filter (5) and then to the screw element.
• When the set maximum operating pressure is reached, the pressure switch turns off the solenoid valve and disconnects the circuit. The suction valve (3) closes the air flow and the compressor enters the “no-load” operating mode. This situation persists until the set minimum system pressure is reached. If energy consumption is low or interrupted, the unit continues to operate in no-load mode for a set period of time, then enters standby mode.