Expert Yogi
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| Precautions for selecting asphalt pump
The diaphragm inside the asphalt pump is also made of nitrile rubber, neoprene, fluororubber, polyvinylidene fluoride, polytetraethylene hexaethylene material I according to different liquid media. The selection of asphalt pump shall be considered from the following aspects:
(1) The shape and structure of the valve core are mainly considered according to the selected flow characteristics, unbalanced force and other factors.
(2) When the fluid concentration is high, the valve seat surface will be seriously damaged by friction. Therefore, the flow path of the valve should be smooth and the internal material of the valve should be hard.
(3) As the medium is corrosive, the valve with simple structure shall be selected as far as possible under the condition of meeting the regulation function.
(4) Temperature and pressure of the medium when the temperature and pressure of the medium are high and change greatly, the valve with small temperature and pressure change of the material of the valve core and valve seat shall be selected.
(5) Prevent flash and cavitation. Flash and cavitation are only produced in liquid medium. In the actual production process, flash and cavitation not only affect the calculation of flow coefficient, but also form vibration and noise, which shortens the service life of the valve. Therefore, when selecting the valve, flash and cavitation should be prevented.
2? Overview of asphalt pump: the asphalt pump is composed of actuator and valve. Using compressed air as the power source, all kinds of corrosive liquids, liquids with particles, high viscosity, volatile, flammable and highly toxic liquids can be pumped and absorbed. It is suitable for various occasions to pump media that cannot be pumped by conventional pumps. Asphalt pump actuators include pneumatic actuators and electric actuators, with models of QBY pneumatic asphalt pump and DBY electric asphalt pump respectively. There are four materials for the main body (valve body) of asphalt pump: plastic, aluminum alloy, cast iron and stainless steel, which are selected according to the requirements of liquid or gas medium. The diaphragm inside the asphalt pump is also made of nitrile rubber, neoprene, fluororubber, polyvinylidene fluoride and polytetraethylene hexaethylene according to different liquid media, so the media type shall be specified when ordering.
3? Specific selection method of asphalt pump:
The action mode of asphalt pump is selected. The action mode of asphalt pump is only available when the pneumatic actuator is selected. Its action mode is formed by the combination of the positive and negative action of the actuator and the positive and negative action of the valve. There are four types of combination, namely positive (gas off type), positive and negative (gas on type), negative (gas on type) and negative (gas off type). The asphalt pump action modes formed by these four combinations include gas on and gas off. The selection of asphalt pump action mode is mainly considered from three aspects:
(1) Process production safety;
(2) Characteristics of medium;
(3) Product quality and small economic loss.
Liquid ring vacuum pump used in wind tunnel test |
Precautions for selecting asphalt pump
