Melt filter for online circulating screen cleaning of recycled plastics, with large filter screen area and implemented without material interruption

Abstract

The invention relates is a melt filter for the online circulating screen cleaning of recycled plastics, with a large filter screen area and implemented without material interruption. The melt filter comprises a hydraulic oil cylinder, large plungers, a filter body, a filter screen, an annular column-shaped flow channel, an internal flow channel, small plungers and a limit plate frame. The filter provided by the invention has the advantages that: the filtering area in a same unit space can be increased by 4-20 times, and the productivity of a single machine can reach more than 1.5 tons/hour; the filter screen is of a spiral slit, trapezoidal sectional filtration slit and polygonal cylinder structure, and can perform online cleaning and be recycled repeatedly, thereby greatly reducing corresponding consumptions; the filter is provided with pre-filling and discharge channels, a material is not interrupted in a screen cleaning process, the production process is performed uninterruptedly, thereby avoiding the loss of materials; each filter-screen plunger body is driven by only a hydraulic oil cylinder so as to realize the linkage of the large and small plungers, therefore, the structure of the filter is greatly simplified, and numerous functional processes are completed smoothly; and by adopting the parallel arrangement of two (or more than two) plunger bodies, the long-term continuous stable operation of the filtration and production processes can be realized.

Description

technical field [0001] The invention relates to a melt filter with long-term on-line circulation cleaning, continuous feeding and super large filter screen area for recycling plastics. The invention belongs to the technical field of plastic melt filtering devices. Background technique [0002] For recycled plastics or plastics containing a large amount of impurities, in the process of plasticizing and extruding, it is necessary to separate the impurities from the plastic melt through a melt filter device. When the impurity content is high or the output is large, the traditional filter device is difficult or even impossible to use. The main problems are: 1) The filter screen of the traditional filter has a small working area, and it will be blocked quickly under the condition of high impurity content. The replacement of the screen will greatly affect the production efficiency and production capacity, and even cause the production process to be unable to continue. With the...

AI Technical Summary

Problems solved by technology

When the impurity content is high or the output is large, the traditional filter device is difficult or even impossible to use. The main problems are: 1) The filter screen of the traditional filter has a small working area, and it will be blocked quickly under the condition of high impurity content. The replacement of the screen will greatly affect the production efficiency and production capacity, and even cause the production process to be unable to continue

With the increase of production capacity, this contradiction becomes more prominent, so it is difficult to improve the production efficiency and capacity scale of plastic recycling operations; 2) The filter screen of the traditional filter device is for one-time use, and is discarded together with foreign materials when replaced after clogging, and the filter screen is consumed The cost is not a small expense; 3) Traditional filters generally use multi-layer woven filter screens, and impurities are easily embedded in the mesh, and it is difficult to remove even with high-pressure material washing. As the embedded impurities continue to increase, the effective filtration area continues to decrease. It can only be discarded after short-term recycling; 4) In the process of changing the screen, usually the output of the die head will be interrupted for a short time, especially after the principle of online flushing is adopted, a large cavity will be formed in the screen changing body, and the die head will be broken. The material phenomenon will be more prominent, resulting in the need to re-establish the production balance every time the filter screen is cleaned, resulting in a large amount of scrap waste

At the same time, the phenomenon of extrusion material breaking will make it difficult to realize the process of underwater granulation

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