Dicing water skimming device

Abstract

The utility model discloses a dicing water skimming device, and belongs to the field of particle treatment of polyolefin extrusion granulation. The continuous skimming and low-cost pelletizing water recycling device is composed of a pelletizing water filter with a pelletizing water nozzle, a pelletizing water tank with an overflow port, a buffer water tank, a low-density polymer basket filter, a pelletizing water flushing pipeline, a reducing tee joint and a pelletizing water pump. An arc-shaped filter screen is arranged in the pelletizing water filter; the pelletizing water spray head is positioned below the outer side of the arc surface of the arc-shaped filter screen; the buffering water tank is located below the pelletizing water filter, a water discharging opening is reserved in the bottom of one end of the buffering water tank, and the lowest end of a water discharging pipeline of the overflow opening and the lowest end of a water discharging pipeline of the buffering water tank are suspended above the low-density polymer basket filter. Most of existing equipment can be modified and upgraded to achieve the use effect, and the device has the advantages that the modification and upgrading cost is low, the labor intensity of personnel is greatly reduced, continuous operation or intermittent operation can be flexibly switched, and the maintenance cost is low.

Description

Technical Field

[0001] The utility model belongs to the technical field of polyolefin extrusion granulation particle processing, and in particular relates to a granulation water skimming device. Background Art

[0002] In order to ensure convenient transportation and performance modification of the polymer produced by the polyolefin device, the fine powder of the polymer produced needs to be melted, extruded, and granulated into polymer particles the size of rice grains. Among them, granulation is to cut and cool the extruded powder-shaped molten polymer at high speed under granulation water (generally, the granulation water used in each production device is desalted water or pure water, which is relatively expensive), and the particles are transported out by the circulation of the granulation water, and then separated from the granulation water, and the granulation water needs to be recycled due to its high price. When the cutter is cut at high speed in the granulator, the blade will cut out polymer fragments, and the granulation water has a high flow rate and dense particles during the process of conveying particles, and the particles inevitably collide and rub in the pipeline, which produces a part of the polymer fragments, and these polymer fragments and fine powders are retained in the granulation water when the particles and the granulation water are centrifuged. In the subsequent filtration process, the granulation water often cannot filter out the polymer fragments with smaller diameters, and they are retained and floated in the granulation water tank. The accumulation of polymer fragments may be sucked into the pelletizing water pump, causing the pelletizing water pump to be sucked empty, the pump to be damaged, and the pelletizing water in the system to be cut off, which will seriously affect production. The traditional way is to open the top of the pelletizing water tank regularly for manual scooping, or to pass a large amount of pelletizing water overflow to discharge the polymer fragments. Manual scooping is very labor-intensive and is done at a high altitude. The polymer fragments produced by some high melt index polymers will increase exponentially, and the pelletizing water tank needs to be passed through steam for water temperature regulation. Manual scooping is also prone to steam burns and other situations. The overflowing pelletizing water is not recycled, and the method of directly discharging it as wastewater undoubtedly increases the consumption of pelletizing water and increases the cost. Even if a pump is used to pump the overflowing pelletizing water back to the pelletizing water tank, the use and maintenance cost of the pump is increased. When there is no pelletizing water overflowing into the pump, the pump is easily damaged. The old problem is solved but a new problem is created. At the same time, in the pelletizing water filtration process, polymer fragments are easily scattered, forming dust pollution, causing trouble to environmental hygiene, and may also cause polymer fragments to be ignited and cause accidents. Utility Model Content

[0003] The utility model provides a pelletizing water skimming device, which solves the above-mentioned related problems in the skimming process of the existing pelletizing water system.

[0004] The utility model discloses a pelletizing water skimming device, which is a device for wet-process continuous skimming and low-cost pelletizing water recovery, and can reduce energy consumption and protect the environment, and reduce the risk of accidents caused by dust dispersion and possible ignition. The device comprises a pelletizing water filter (1) with a pelletizing water nozzle (3), a pelletizing water tank (2) with an overflow port (6), a buffer water tank (4), a low-density polymer basket filter (5), a pelletizing water flushing pipeline (7), a reducing tee (8) and a pelletizing water pump (9); an arc-shaped filter screen is arranged in the pelletizing water filter (1), and the pelletizing water nozzle (3) is located at the arc-shaped filter screen. The buffer water tank (4) is located below the pelletizing water filter (1), a water outlet is left at the bottom of one end of the buffer water tank (4), and a partition lower than the upper edge of the buffer water tank (4) is arranged next to the water outlet to divide the buffer water tank (4) into two parts; the low-density polymer basket filter (5) is located directly below the water outlet of the buffer water tank (4); the pelletizing water filter (1) is located above the pelletizing water tank (2); and the lower ends of the water outlet pipeline of the overflow port (6) and the water outlet pipeline of the buffer water tank (4) are suspended 50 cm to 70 cm above the low-density polymer basket filter (5).

[0005] Fresh pelletizing water is added to the pelletizing water tank (2), and the pelletizing water pump (9) transports the pelletizing water in the pelletizing water tank (2) to the pelletizer. The pelletizing water containing low-density polymer powder obtained after pelletizing is separated from the low-density polymer particles in a polymer particle centrifugal dryer, and the pelletizing water carrying the low-density polymer powder enters a pelletizing water filter (1) with an arc-shaped filter screen; a partition is provided in the pelletizing water filter (1), the bottom end of the partition is connected to the pelletizing water filter (1), and the top end of the partition is connected to the arc-shaped filter screen; the pelletizing water liquid level is After rising over the top of the partition, it flows from top to bottom through the inner side of the arc surface of the arc filter. The low-density polymer powder with larger particle size remains on the inner side of the arc surface of the arc filter. The pelletizing water carries the low-density polymer powder with smaller particle size (including some metal fragments that may fall off in the pelletizing water system to prevent damage to the equipment in the system) through the arc filter and enters the pelletizing water tank (2). The mesh of the arc filter cannot be too small to expect to filter all the polymer powder, otherwise it will lead to low filtration efficiency. The pelletizing water flow rate of large-scale production equipment is often 600m 3 / h or more, such a large flow of pelletizing water cannot be quickly filtered and processed, and this link can only be coarsely filtered; a pelletizing water nozzle (3) with a settable spray frequency is arranged at the lower part of the outer side of the arc surface of the arc filter screen of the pelletizing water filter (1), and is controlled by a solenoid valve or a pneumatic valve. The spray interval can be increased or decreased according to the accumulation of large-size low-density polymer fragments on the arc filter screen, and fresh pelletizing water is sprayed to the outer side of the arc surface of the arc filter screen of the pelletizing water filter (1) at regular intervals to remove the pelletizing water attached to the inner side of the arc surface of the arc filter screen. The large-sized low-density polymer powder is washed down and flows along the lower inner edge of the arc surface of the arc-shaped filter screen to the buffer water tank (4) below the pelletizing water filter (1); the fresh pelletizing water sprayed by the pelletizing water nozzle (3) passes through the arc-shaped filter screen, is blocked by the cover of the pelletizing water filter (1) and flows into the buffer water tank (4), so that the arc-shaped filter screen only needs a small amount of pelletizing water to be cleaned, no manual cleaning is required, and it can work continuously without interruption; the buffer water tank (4) is a rectangular parallelepiped structure, covering the arc surface of the arc-shaped filter screen. In the area where the larger particle size low-density polymer and pelletizing water drop on the inner side of the surface, a drain is left at the bottom of one end of the buffer water tank (4), and a partition lower than the upper edge of the buffer water tank (4) is arranged next to the drain to divide the buffer water tank (4) into two parts, so that the buffer water tank (4) can accumulate a certain liquid level, so that the larger particle size low-density polymer fragments washed down can float on the pelletizing water. As the pelletizing water spraying time increases, the larger particle size low-density polymer fragments floating in the buffer water tank (4) will overflow the partition. , is carried by the pelletizing water into the low-density polymer basket filter (5) below the buffer water tank (4) (its structure is a funnel with a liftable arc-shaped filter basket installed in it to filter water; the mesh of the arc-shaped filter is smaller than the particle size of the small-sized low-density polymer powder). During the whole process, the large-sized low-density polymer powder flows simultaneously with the pelletizing water, so it will not fall everywhere to affect environmental hygiene and form dust hazards, which is highly efficient and environmentally friendly, and will not adhere to the pipe wall due to premature dehydration to cause blockage.

[0006] After being filtered by the pelletizing water filter (1), the pelletizing water carrying the low-density polymer crumbs with smaller particle sizes enters the pelletizing water tank (2), and the low-density polymer crumbs with smaller particle sizes float on the surface of the pelletizing water. An overflow port (6) is provided on the upper side of the pelletizing water tank (2), and fresh pelletizing water can be added to allow the low-density polymer crumbs to be carried out along with the overflow of the pelletizing water and enter the low-density polymer basket filter (5) with a filter screen below; at this time, the low-density polymer crumbs with larger and smaller particle sizes are all collected together. When the low-density polymer basket filter (5) is full, it is only necessary to lift out the arc-shaped filter basket, clean it into a woven bag and transport it away. A pelletizing water flushing pipeline (7) is arranged in the pelletizing water tank (2) at a position flush with and opposite to the overflow port (6), and the pelletizing water flushing pipeline (7) is provided with a fourth switch valve (V-4); a pelletizing water pump (9) is arranged on the pelletizing water tank (2) on the same side as the pelletizing water flushing pipeline (7); the pelletizing water in the pelletizing water tank (2) is obtained by the pelletizing water pump (9) to obtain high-flow pelletizing water and is divided into three paths; the first path of high-flow pelletizing water enters the pelletizing water tank (2) after passing through the pelletizing water flushing pipeline (7) to disturb the water surface, thereby destroying the agglomeration of small-diameter low-density polymer fragments, so that the low-density polymer fragments are not easily accumulated at the corners of the pelletizing water tank (2) and are more easily carried out by the pelletizing water;

[0007] The second high-flow pelletizing water obtained from the pelletizing water pump (9) is transported by a branch pipeline, passes through the bottom of the low-density polymer basket filter (5), and then returns to the pelletizing water tank (2) from the top. The branch pipeline below the low-density polymer basket filter (5) is a reduced diameter structure, and a pipeline connected to the low-density polymer basket filter (5) is arranged at the reduced diameter position to obtain a reduced diameter tee (8). According to Bernoulli's law, the pelletizing water flow rate at the reduced diameter position will increase, and its pipeline pressure will decrease, so that the pelletizing water filtered out of the low-density polymer basket filter (5) is passed through the reduced diameter tee (8). ) position is sucked into the branch pipeline, and then returned to the pelletizing water tank (2) from the top; due to the low internal pressure of the reducing tee (8), even when the low-density polymer basket filter (5) is not filtering, that is, when no pelletizing water from the low-density polymer basket filter (5) enters the reducing tee (8), the pelletizing water in the reducing tee (8) will not be sprayed out, but air will be sucked into the branch pipeline; at this point, the pelletizing water overflowing from the overflow port (6) returns to the pelletizing water tank (2). By using this principle, there is no need to set up a special pump, reducing energy consumption and maintenance costs. The third high-flow pelletizing water obtained from the pelletizing water pump (9) enters the pelletizer for pelletizing after passing through the pipeline. The pelletizing water containing low-density polymer powder obtained after pelletizing is separated from the low-density polymer particles in the polymer particle centrifugal dryer to obtain pelletizing water carrying low-density polymer powder.

[0008] The front and rear ends of the reducing tee (8) are provided with a first switch valve (V-1) and a second switch valve (V-2), and a third switch valve (V-3) is provided on the pipeline connected to the low-density polymer basket filter (5). When the device is in operation, the first switch valve (V-1) and the second switch valve (V-2) are opened first, and then the third switch valve (V-3) is opened; when the device is stopped, the third switch valve (V-3) is closed first, and then the first switch valve (V-1) and the second switch valve (V-2) are closed.

[0009] The working process of the device of the utility model is that fresh pelletizing water is firstly continuously added to make the pelletizing water tank (2) reach an overflow state, and after the overflow begins, the fresh pelletizing water can be turned off when the low-density polymer crumbs can be brought out, and the pelletizing water overflowing out will be recycled into the pelletizing water tank (2) to play a role in replenishing water, thus entering the "overflow-recycling-overflow" cycle state; when the pelletizing water tank (2) cannot overflow due to pelletizing water loss, some fresh pelletizing water is added again, so that the device can restore the "overflow-recycling-overflow" cycle state.

[0010] The pelletizing water after low-density polymer granulation contains low-density polymer fragments that affect the continued recycling of pelletizing water. The device described in the utility model can remove the low-density polymer fragments to ensure the recycling of pelletizing water, and can collect the low-density polymer fragments more safely and hygienically. The utility model can be modified and upgraded on most existing equipment to achieve the use effect, and has the advantages of low modification and upgrading cost, greatly reducing the labor intensity of personnel, flexible switching between continuous or intermittent operation, and low maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 : A schematic structural diagram of the environmentally friendly pelletizing water skimming device of the utility model;

[0012] Among them, there are a pelletizing water filter (1), a pelletizing water tank (2), a pelletizing water nozzle (3), a buffer water tank (4), a low-density polymer basket filter (5), a pelletizing water tank overflow port (6), a pelletizing water tank pelletizing water flushing pipeline (7), a reducing tee (8), and a pelletizing water pump (9). DETAILED DESCRIPTION

[0013] Embodiment 1:

[0014] like Figure 1As shown, after the fresh pelletizing water is introduced into and filled up through the fresh pelletizing water pipeline on the pelletizing water tank (2), the pelletizing water pump (9) is started. At this time, valves V-1, V-2, V-3, and V-4 are all in a closed state, and the pelletizing water is transported to the pelletizer. Low-density polymer particles containing low-density polymer powder are cut out in the pelletizer. The pelletizing water is used to transport and cool the low-density polymer particles. The pelletizing water and the low-density polymer particles are separated in a polymer particle centrifugal dryer, and the separated low-density polymer particles are sent to the subsequent process for drying; the pelletizing water carrying the low-density polymer powder enters the pelletizing water filter (1) for the first coarse filtration, and the pelletizing water after filtration carries the low-density polymer powder with a smaller particle size and enters the pelletizing water tank (2). The relatively large-sized low-density polymer fragments filtered on the inner side of the arc surface of the arc-shaped filter screen of the pelletizing water filter (1) are washed into the buffer water tank (4) below by the pelletizing water nozzle (3) and float on the pelletizing water surface. As the water surface rises, they pass through the partition of the buffer water tank (4) and enter the low-density polymer basket filter (5) below, where the relatively large-sized low-density polymer fragments are separated from the pelletizing water. The pelletizing water filtered by the arc filter of the pelletizing water filter (1) enters the pelletizing water tank (2), and the small-sized low-density polymer particles contained therein float on the water surface. Fresh pelletizing water is introduced through the fresh pelletizing water pipeline on the pelletizing water tank (2), and the amount of water introduced can make the pelletizing water in the pelletizing water tank (2) slowly overflow from the overflow port (6). The small-sized low-density polymer crumbs carried by it enter the low-density polymer basket filter (5), and the small-sized low-density polymer crumbs are separated from the pelletizing water; the pelletizing water separated by the second branch enters the reduced diameter tee (8) position of the pelletizing water branch pipeline below, and the valves V-1 and V-2 are opened to establish the flow, and then the valve V-3 is opened, and the pelletizing water separated by the low-density polymer basket filter (5) is brought back to the pelletizing water tank (2). When the low-density polymer crumb basket filter is full of crumbs, it is taken out, cleaned, and then put back. This embodiment is suitable for a pelletizing water tank with less crumbs and no crumbs aggregation.

[0015] Embodiment 2:

[0016] During the use of Example 1, if the pelletizing water tank cannot completely overflow the low-density polymer crumbs, the crumbs accumulate in the water tank. At this time, the amount of fresh pelletizing water introduced can be increased, and the valve V-4 of the pelletizing water flushing pipeline can be opened at the same time to break up the accumulated crumbs on the water surface to disturb the water surface, so that the accumulated low-density polymer crumbs overflow and enter the low-density polymer basket filter (5) below. The operation can be intermittent to leave time for cleaning the low-density polymer basket filter (5).

[0017] The utility model pelletizing water filter (1) has an arc filter screen with a pore size of 0.8 mm, and the filter screen pore sizes of the low-density polymer basket filter (5) are 5 μm and 10 μm, which can be switched at any time according to the particle size of the generated low-density polymer powder.

[0018] All equipment involved in this utility model is made of 304 stainless steel.

[0019] The pipe diameter selection of the pelletizing water branch pipeline with a reducing tee (8) in the utility model is, if it is a large-scale production device with an annual output of hundreds of thousands of tons, it is recommended that the pipe diameter be 2" before the reduction and 1" after the reduction. The pipe diameter of the pelletizing water flushing pipeline is 1".

[0020] The pelletizing water pump (9) selected in the utility model is a centrifugal pump, the material should be stainless steel, and the pump flow rate can reach 650m 3 / h; Set up two units, one in operation and one as backup.

[0021] The valve selected by the utility model is a stainless steel valve.

Claims

1. A pelletizing water skimming device, characterized in that: The invention comprises a pelletizing water filter (1) with a pelletizing water nozzle (3), a pelletizing water tank (2) with an overflow port (6), a buffer water tank (4), a low-density polymer basket filter (5), a pelletizing water flushing pipeline (7), a reducing tee (8) and a pelletizing water pump (9); the pelletizing water filter (1) is located above the pelletizing water tank (2), and pelletizing water carrying low-density polymer powder enters the pelletizing water filter (1); an arc-shaped filter screen is arranged in the pelletizing water filter (1), and low-density polymer powder with a larger particle size is retained on the inner side of the arc surface of the arc-shaped filter screen, while pelletizing water with a larger particle size is retained on the inner side of the arc surface of the arc-shaped filter screen. The pellet water carries the low-density polymer powder with a smaller particle size through the arc-shaped filter screen and enters the pelletizing water tank (2); the buffer water tank (4) is located below the pelletizing water filter (1); a water outlet is left at the bottom of one end of the buffer water tank (4); a partition lower than the upper edge of the buffer water tank (4) is arranged next to the water outlet to divide the buffer water tank (4) into two parts; the low-density polymer basket filter (5) is located directly below the water outlet of the buffer water tank (4); the water outlet pipeline of the overflow port (6) and the lower end of the water outlet pipeline of the buffer water tank (4) are suspended above the low-density polymer basket filter (5); ) 50 cm to 70 cm above the arc surface of the arc-shaped filter; the pelletizing water nozzle (3) is located below the outer side of the arc surface of the arc-shaped filter screen, and the buffer water tank (4) covers the area where the large-diameter low-density polymer and the pelletizing water droplets fall on the inner side of the arc surface of the arc-shaped filter screen; a pelletizing water flushing pipeline (7) is arranged in the pelletizing water tank (2) at a position flush with and opposite to the overflow port (6); a pelletizing water pump (9) is arranged on the same side of the pelletizing water tank (2) as the pelletizing water flushing pipeline (7); the pelletizing water in the pelletizing water tank (2) is obtained by the pelletizing water pump (9) to obtain high-flow pelletizing water and is divided into three paths; the first The first high-flow pelletizing water passes through a pelletizing water flushing pipeline (7) and then enters a pelletizing water tank (2); the second high-flow pelletizing water obtained from a pelletizing water pump (9) is transported by a branch pipeline, passes through the bottom of a low-density polymer basket filter (5) and then returns to the pelletizing water tank (2) from the top; the branch pipeline below the low-density polymer basket filter (5) is a reduced diameter structure, and a pipeline connected to the low-density polymer basket filter (5) is arranged at the reduced diameter position to obtain a reduced diameter tee (8); the third high-flow pelletizing water obtained from the pelletizing water pump (9) passes through a pipeline and then enters a pelletizer.

2. A pelletizing water skimming device as claimed in claim 1, characterized in that: A fourth switch valve (V-4) is provided on the pelletizing water flushing pipeline (7), a first switch valve (V-1) and a second switch valve (V-2) are provided at the front and rear ends of the reducing tee (8), and a third switch valve (V-3) is provided on the pipeline connected to the low-density polymer basket filter (5).

3. A pelletizing water skimming device as claimed in claim 1, characterized in that: The pore size of the arc filter screen of the pelletizing water filter (1) is 0.8 mm, and the pore size of the filter screen of the low-density polymer basket filter (5) is 5 μm or 10 μm.

4. A pelletizing water skimming device as claimed in claim 1, characterized in that: The pelletizing water pump (9) is a centrifugal pump, two of which are provided, one for operation and one for standby.

5. A pelletizing water skimming device as claimed in claim 1, characterized in that: The pelletizing water nozzle (3) can set the spray frequency and is controlled by a solenoid valve or a pneumatic valve.

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