How to solve the problem of pressure difference of mesh screen changer
At present, uninterrupted screen changer is widely used in domestic plastics industry to filter impurities and condensed particles in melt. When the pressure difference of screen changer rises to a certain extent, it is switched to stand-by. In the case of stable impurity particles in the melt, the switching period of the screen changer is mainly determined by the initial pressure difference of the screen changer, the accuracy of the filter material, the ability to absorb pollution, the cleaning effect of the filter material and the area of the screen changer.
The net screen changer used in a chemical fiber factory is Haike non-stop net changer. The net changer consists of heating outer barrel, three-way valve, inner barrel and filter element. The heated outer barrel of the screen changer is used to heat and insulate the inner barrel and filter element, and fix the three-way valve and inner barrel. The main contacts with the melt are inner barrel and three-way valve. The screen changer consists of 31 filter elements, each of which has a filter area of 0.7 square meters. The filter material of the filter element is stainless steel sintered filter material, and its pollution absorption energy is high. Inside the filter material, there are double stainless steel nets and stainless steel porous inner tubes for support.
The pressure difference of the screen changer consists of the empty barrel pressure difference of the screen changer, the pressure difference of the filter material and the pressure difference formed by the material supporting the filter material. The pressure difference of the melt screen changer rises depending on the ability of the filter material to absorb contamination and the quality of impurities remaining in the filter element after cleaning. With the improvement of filtration accuracy, the ability of filter material to absorb contamination decreases significantly. Therefore, it is of great help to prolong the service life of screen changer to select the filter element with low accuracy as far as possible under the condition of technological permission.