Screw vacuum pump in distillation process
With sulfolane vacuum technology as an example, the process of vacuum medium containing butadiene and sulfur dioxide, and the butadiene in high temperature, corrosive sulfur dioxide, the decompression for sulfolane vacuum technology, on the basis of selection of vacuum pump and operating problems, and the corrosive medium in with the screw vacuum pump selection Suggestions are put forward.
When the screw vacuum pump is running, the piston in the cylinder reciprocates through the action of crankshaft connecting rod mechanism (rotary motion changes into linear motion) driven by the motor. When the piston within the cylinder when the movement from left to right, because the left cavity of the cylinder volume increasing, reduce the pressure of the left cavity space constant, when the pressure inside the left cavity space is less than the pressure of the pump container, according to the principle of balance of gas pressure, gas is pumped container through the suction valve are constantly pumping into the left cavity, is in the process of suction.
When the piston reaches its right-most position, the left cavity of the cylinder is filled with gas. Then the piston moves from the right end to the left end, and the suction valve closes automatically. The gas is compressed as the piston moves from right to left. When the gas in the cylinder reaches the exhaust pressure, the exhaust valve is opened and the gas is discharged, completing a work cycle. When the piston is moving from the left end to the right end, repeat the cycle until the pumped container reaches an equilibrium pressure.
In screw vacuum pump, the suction valve and exhaust valve is a very important component and is vulnerable parts of their work is good or bad directly affect the limit pressure reciprocating pump, extraction rate, power consumption and reliability of operation.
Because of the dry screw vacuum pump in low vacuum degree, energy saving, environmental protection, emission reduction and other aspects of advantages, in some chemical occasions, dry screw vacuum pump is replacing the traditional chemical pump, such as liquid ring vacuum pump, vapor jet pump, liquid jet pump, once-through oil seal pump, etc., for different medium and condition, dry screw vacuum pump selection should be targeted, if improper selection of screw vacuum pump damage easily.