Vacuum pump in vacuum extruder system

 

Extruder is widely used in the production of plastic products. After the material is heated and extruded by extruder, the plastic is extruded from the head of the extruder. In the process of extruder processing, the raw materials in the extruder appear gasification, decomposition and precipitation in different degrees at high temperature, resulting in a large number of gases and precipitates and other low molecular substances. In the process of heating and extruding the raw materials by the extruder, the raw materials are in the semi closed heating pipe of the extruder, and the low molecular substances can not be released well and mixed in the production The product surface is not smooth, the production process is not smooth, the mechanical properties of the product are decreased, and the product is not dense. In order to effectively remove the low molecular substances from the heating pipe, a vacuum device is connected to the heating pipe of the extruder, and the low molecular substances are separated and discharged from the molten raw materials by the vacuum device.

Operation method of vacuum pump in vacuum extruder system

(1) Check the condition of vacuum extruder and vacuum pump carefully, and ask for adding appropriate lubricating oil or grease to reducer, vacuum pump and lubricating points of vacuum extruder according to the product operation manual. Before starting the vacuum pump, in addition to the normal inspection of the integrity and fastening of its parts, it is also necessary to turn the flywheel by hand to see if there is jamming and abnormal sound.

(2) When starting the machine normally, the cooling water for vacuum pump should be connected first, then the driving motor of vacuum pump can be started, and finally the driving motor of vacuum extruder should be started; when the machine is shut down, the second is just the opposite. When opening the cooling water, the water should be discharged from the water outlet of the machine, and then close the main intake valve to start the machine without load. Only when the machine reaches the normal speed can the main air inlet valve be opened slowly, so as to avoid losing lubrication due to low vacuum pressure.

(3) Before stopping the machine, first stop adding mud, and then stop the driving motor of vacuum extruder, and finally stop the driving motor of vacuum pump after the mud extruding screw shaft continues to rotate and the brick and tile body has no axial movement.

The feeding port and the outlet of the machine nozzle should be sealed with a clean plastic cloth to prevent the sludge from dehydrating and hardening and affecting the restart of the vacuum extruder. If the machine is shut down for a long time, the sludge inside the machine should be removed. Otherwise, the vacuum extruder can not be started after the mud dries up.

(4) When the vacuum extruder is put into operation for the first time, it should be operated for 1 ~ 2 hours without load, and then put into operation with mud for 1 ~ 2 hours. If there is no abnormality, it can be put into consumption operation. After the mud is mixed, it should be extruded. Then start the vacuum pump, and only when the vacuum gauge reaches the regular vacuum value, can the qualified brick and tile body be extruded. Since the brick and tile body extruded at the start-up has not been vacuum degassed or the vacuum degassing treatment is not perfect, it should be put into the vacuum extruder again for disposal before qualified brick and tile body can be obtained. The moisture content of the slurry should be uniform, usually about 18%. In addition, the speed of adding mud should be uniform and the amount of mud should not be too much, and pay attention to observe whether the value of the vacuum gauge can be within the regular range.

(5) Adhere to a certain height of vacuum pump vacuum, avoid too low vacuum. The vacuum pump oil used in the vacuum pump is vacuum suction pump body, so in operation, the vacuum degree of the pump itself should be maintained above 0.06mpa to maintain itself

There is enough lubrication. Because the lower the vacuum degree of the equipment being vacuumed, the more air it needs to draw out, the greater the displacement of the vacuum pump. So the vacuum pump in the low vacuum state when working in the exhaust gas “soot” is also more.

(6) Do a good job in cooling the vacuum pump. In order to make the vacuum extruder get higher vacuum degree, the amount of gas flowing through the vacuum pump is bound to reduce, and a large amount of heat generated in the vacuum pump cavity must be absorbed and distributed to the outside atmosphere by the pump body. If the cooling measures are not taken or the cooling measures are not taken, the heat can not be balanced and distributed to the outside atmosphere. This will constitute a sharp rise in the temperature of the vacuum pump body and forced to stop running. The temperature rise of vacuum pump should be checked frequently. If there is any abnormality, the “car” should be stopped immediately for inspection. After the defects are eliminated, the “car” can not work with “disease”.

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