Compact screen changing device applied to ultra-large type extrusion granulating unit

Abstract

The utility model belongs to the technical field of melt filtering screen changing devices, and discloses a compact screen changing device applied to an ultra-large type extrusion granulating unit. The device is mainly composed of a screen changing shell, a sliding column, a sealing water jacket and a filter screen. Two axial through holes are formed in the screen changing shell, sliding columns are installed in the through holes, and filter screens are installed in the sliding columns. Sealing water jackets are installed at the left end and the right end of the screen changing shell, and melt self-sealing is achieved. The front side and the rear side of the screen changing shell are provided with a feeding inclined flow channel and a discharging straight flow channel, and the flow channels are communicated with the hollowed-out parts of the upper sliding column and the lower sliding column respectively. Wherein the plane of the discharging runner is parallel to the left and right end faces, and the left and right end faces of the plane of the feeding runner form a certain angle. The inclined feeding design is adopted for the shell of the screen changing device, so that the structure of the screen changing device is more compact compared with a conventional screen changing device, the occupied space is reduced, the stroke of the sliding column is shortened, and the screen changing efficiency is improved. Meanwhile, under the same specification, the weight of the screen changing shell and the sliding column is reduced, and the cost is effectively reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to melt filter screen changing device technical field especially relates to a compact screen changing device for super large extrusion granulator unit. BACKGROUND

[0002] In the field of plastic processing, extrusion granulation is the most important processing method. Because the plastic raw material generally contains various impurities, if these impurities are not treated directly participate in the extrusion process, it will seriously affect the quality and performance of the final product. Therefore, a filter device is installed at the front end of the extruder to effectively remove impurities in the raw material and ensure that the product quality of the extrusion granulation meets the standards. With the continuous development of plastic extrusion equipment towards large-scale, high-yield and high-efficiency, the overall specifications of the equipment have also increased significantly. Although this trend has improved production efficiency, it has also brought new problems: the increase in volume and weight of the equipment has led to an increase in manufacturing costs, an expansion of the occupied area, and a significant increase in energy consumption. In addition, when replacing the filter screen of the super large equipment, the operation is complex and time-consuming, which seriously affects the continuity and efficiency of the production line.

[0003] In the design of conventional specification screen changing device, straight channel structure is widely used. However, this design has obvious redundancy problems when applied to super large granulation equipment. Not only does it increase the volume and weight of the screen changing device, but it also leads to an increase in design cost and an expansion of the occupied area. More seriously, during the screen changing process, the slide column needs to move a large stroke, which not only greatly reduces the screen changing efficiency, but also increases the operation difficulty and fault risk. INNOVATION CONTENT

[0004] The utility model aims at providing a compact screen changing device for super large extrusion granulator unit, which aims to improve product yield, achieve compact structure through optimized design, reduce material cost and reduce occupied area, and thus promote the sustainable development of the plastic processing industry.

[0005] The utility model adopts the technical scheme that a compact screen changing device for super large extrusion granulator unit, including screen changing shell 1, slide column 2, sealing water jacket 3 and filter screen 4;

[0006] Two sealing water jackets 3 are respectively arranged at the left and right ends of the screen changing shell 1, and the screen changing shell 1 is provided with two through holes; the slide column 2 is installed in the through hole and slides in the through hole; a part of the slide column 2 is hollow, and the filter screen 4 is arranged on the hollow position; the inlet flow channel and the outlet flow channel are respectively arranged on the front side and the rear side of the screen changing shell 1 and are in communication with the hollow part of the slide column 2; the inlet flow channel is inclined, and the outlet flow channel is straight.

[0007] The plane where the feeding inclined flow channel of the screen changing housing 1 is located and the axial plane of the slide post 2 form a certain angle, which is used to reduce the volume of the housing and the length of the slide post.

[0008] The range of the angle is limited by the axial width of the hollowed part, and the angle is taken as the largest value in the allowable range on the basis that the angle cannot exceed the spatial limit of the structure of the hollowed part; the structure of the hollowed part is determined by the material yield and the pressure difference of the filter screen 4; meanwhile, the hollowed part also needs to ensure that the shear rate of the material in the flow is greater than 8 s -1 The shear stress of the wall surface of the screen changing housing 1 in contact with the material is less than 140 KPa.

[0009] A method for using a compact screen changing device applied to an ultra-large extrusion granulator set, when the filter screen 4 is replaced, the cooling water in the sealing water jacket 3 is stopped, one of the slide posts 2 is pushed out at one end, the filter screen 4 is exposed, the filter screen 4 is replaced, the slide post 2 that is pushed out is pulled back to the exhaust position at the other end, the air in the hollowed part of the slide post 2 is exhausted, after the exhaust, the slide post 2 is readjusted to the working position, the other slide post 2 repeats the above operation, and finally the cooling water in the sealing water jacket 3 is passed to restore the normal working state.

[0010] During the pushing out and pulling back of the slide post 2, it is necessary to ensure that the hollowed part of the slide post 2 remains in a relatively closed state.

[0011] The relatively closed state is that, during the pushing out of the slide post 2, the hollowed part of the slide post 2 just leaves the entrance of the screen changing device, at this time, the other end of the hollowed part has not left the sealing water jacket 3, so that the hollowed part is in the relatively closed state.

[0012] The beneficial effects of the utility model are as follows:

[0013] (1) The structure is compact, and the material cost is lower;

[0014] (2) The stroke of the slide post is short, and the screen changing speed is high;

[0015] (3) The volume of the housing and the slide post is smaller than that of a conventional screen changing device of the same specification, and the occupied area is reduced. DRAWINGS

[0016] Figure 1 It is a structural schematic view of a compact screen changing device applied to an ultra-large extrusion granulator set;

[0017] Figure 2 It is a structural sectional view of a compact screen changing device applied to an ultra-large extrusion granulator set;

[0018] Figure 3 It is a comparison schematic view of the relatively closed position of the hollowed part of the slide post of the screen changing device of the utility model and a conventional screen changing device. CONCRETE EMBODIMENT

[0019] This utility model designs a compact screen changing device for use in ultra-large extrusion granulation units, comprising a screen changing housing 1, sliding columns 2, sealing water jackets 3, and a filter screen 4. The screen changing housing 1 has two axial through holes, within which sliding columns 2 are installed, arranged vertically. Each sliding column 2 has a hollowed-out portion, on which a filter screen 4 is installed. An inclined feed channel and a straight discharge channel are respectively opened on the front and rear sides of the screen changing housing 1, and these two channels communicate with the hollowed-out portions of the two vertically arranged sliding columns 2. Sealing water jackets are installed at both ends of the screen changing housing 1 to ensure the device's airtightness.

[0020] The plane of the feed inclined flow channel of the screen changing shell 1 is at a certain angle to the axial plane of the slide column 2.

[0021] like Figure 1 The compact screen changing device shown, applied to ultra-large extrusion granulation units, mainly consists of a screen changing shell 1, sliding columns 2, sealing water jackets 3, and a filter screen 4. The screen changing shell 1 has two axial through holes, within which the sliding columns 2 are installed. The filter screen is installed in the hollowed-out portion of the sliding columns 2. Sealing water jackets 3 are installed at both ends of the screen changing shell 1 to achieve melt self-sealing. The screen changing shell 1 has inlet and outlet channels on its front and rear sides. The plane of the outlet channel is perpendicular to the axial plane of the sliding columns, while the plane of the inlet channel forms a certain angle with the axial plane of the sliding columns. The inlet and outlet channels are respectively connected to the hollowed-out portions of the upper and lower sliding columns 2.

[0022] When the screen changing device is in operation, the molten material is diverted through the feed channel and enters the hollowed-out sections of the upper and lower sliding columns 2 through the two diversion channels. The material then passes through the filter screen 4 and flows into the discharge channel, finally being discharged from the discharge port. As impurities gradually increase on the filter screen in the hollowed-out section, the screen changing device needs to replace the filter screen when the pressure difference between the inlet and outlet reaches a certain set value.

[0023] During filter replacement, firstly, production output should be appropriately reduced to ensure operational safety. Then, stop supplying cooling water to the sealing water jacket 3, push the upper sliding column to the right to expose filter 4, and replace filter 4. Next, pull the upper sliding column back to the left to the venting position to expel air from the hollowed-out portion of the sliding column 2. After venting, readjust the upper sliding column 2 to its working position, and repeat the operation of the upper sliding column with the lower sliding column. Finally, circulate cooling water through the sealing water jacket 3 to restore the filter replacement device to normal operating status.

[0024] It is particularly important to note that during the extension and retraction of slide bar 2, it is essential to ensure that the openwork portion of slide bar 2 remains in a relatively closed state for a period of time. Figure 3 The purpose of this is to prevent the material at the feed inlet from communicating with the atmosphere through the perforated section, thereby avoiding material from flowing directly into the atmosphere, which would result in material waste and threaten personnel safety.

[0025] The utility model has remarkable characteristics compared with similar products: because the utility model adopts the feeding inclined runner on the feeding port of the screen changing shell 1, this design can effectively reduce the stroke of the slide column, and the shell structure is more compact. Figure 3 It can be seen that, compared with the screen changing device adopting the feeding straight runner structure form, the feeding inclined runner of the utility model effectively reduces the use of redundant materials, and in the large screen changing device, this improvement can significantly improve the space utilization and reduce the material cost.

Claims

1. A compact screen changer applied to an ultra-large extrusion granulator unit, characterized in that, It comprises a screen changing housing (1), a slide post (2), a sealing water jacket (3) and a filter screen (4); The screen changing housing (1) is provided with two sealing water jackets (3) at its left and right ends, and is provided with two through holes; the slide post (2) is installed in the through holes and slides in the through holes; a part of the slide post (2) is hollowed, and the filter screen (4) is installed on the hollowed position; the feed flow channel and the discharge flow channel are respectively formed on the front side and the rear side of the screen changing housing (1) and are communicated with the hollowed part of the slide post (2); the feed flow channel is inclined, and the discharge flow channel is straight.

2. The compact screen changer for use in an ultra-large extrusion prilling unit according to claim 1, wherein The plane of the inclined feed flow channel of the screen changing housing (1) and the axial plane of the slide post (2) form a certain angle, which is used for reducing the volume of the housing and the length of the slide post.

3. The compact screen changer for use in an ultra-large extrusion prilling unit according to claim 2, wherein The range of the oblique angle is limited by the axial width of the hollowed-out part, and the oblique angle takes the largest value in the allowable range on the basis that the oblique angle cannot exceed the spatial limit of the hollowed-out part structure; the hollowed-out part structure is determined by the material yield and the pressure difference of the filter screen (4); meanwhile, the hollowed-out part also needs to ensure that the shear rate of the material in flow is greater than 8 s -1 The shear stress of the wall surface of the screen changing shell (1) in contact with the material is less than 140 KPa.

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