Polypropylene pellet hydraulic conveying system and method

Abstract

The present application relates to polypropylene particle material post-processing system, especially to a kind of polypropylene particle hydraulic conveying system, comprising: hydraulic conveying material distributor and the particle centrifugal dryer being communicated with it, also including a circulating water tank, and the particle centrifugal dryer is communicated;Ultra-high molecular weight polyethylene filter is communicated with hydraulic conveying material distributor;Circulating water tank is transported to ultra-high molecular weight polyethylene filter by circulating water pump with the conveying water of circulating water tank;The purified water output by ultra-high molecular weight polyethylene filter enters hydraulic conveying material distributor and is used as backflush water, and the dust-containing conveying water output enters hydraulic conveying material distributor as conveying water through conveying pipe, and the backflush water pressure entering hydraulic conveying material distributor is higher than the conveying water pressure.The present application uses hydraulic conveying to realize the conveying process of water-containing polypropylene particles to high-position equipment, avoids the problem that a large amount of conveying water enters upstream VOC equipment due to the fact that conveying water pressure is higher than upstream VOC equipment, so that VOC equipment cannot work normally.

Description

TECHNICAL FIELD

[0001] The present application relates to a polypropylene particle material post-processing system, in particular to a polypropylene particle hydraulic conveying system and method. BACKGROUND

[0002] Polypropylene is a colorless, odorless, non-toxic, translucent solid. Polypropylene is a kind of excellent thermoplastic synthetic resin, which is colorless and translucent, thermoplastic, light weight and general plastic, has chemical resistance, heat resistance, electrical insulation, high strength mechanical properties and good high wear resistance processing performance, etc. Polypropylene is widely used in many fields such as machinery, automobile, electronics, building, textile, packaging, agriculture, forestry, fishery and food industry. In recent years, with the rapid development of packaging, electronics, automobile and other industries in China, the development of China's industry has been greatly promoted, and because of its plasticity, polypropylene materials are gradually replacing wooden products, high strength toughness and high wear resistance have gradually replaced the mechanical function of metal, in addition, polypropylene has good grafting and composite function, and has great application space in concrete, textile, packaging and agriculture, forestry and fishery.

[0003] After the polypropylene particles are removed from VOC by steam method, the surface of the particles contains a large amount of steam condensate, which needs to be dried. However, due to the high and large VOC removal equipment, the installation position of the drying equipment is usually higher than the discharge port of the VOC removal equipment, and the water-containing polypropylene particles cannot be conveyed by the air conveying system. SUMMARY

[0004] In view of the above-mentioned deficiencies of the prior art, the purpose of the present application is to provide a polypropylene particle hydraulic conveying system, which realizes the conveying of water-containing polypropylene particles to high-position equipment and solves the problem of conveying water-containing polypropylene particles.

[0005] In order to achieve the above-mentioned purpose, the present application provides a polypropylene particle hydraulic conveying system, comprising:

[0006] a hydraulic conveying material transfer device;

[0007] and a particle centrifugal dryer in communication with the hydraulic conveying material transfer device; characterized in that: further comprising a circulating water tank in communication with the particle centrifugal dryer;

[0008] an ultrahigh molecular weight polyethylene filter in communication with the hydraulic conveying material transfer device;

[0009] The circulating water tank delivers the conveying water in the circulating water tank to the ultrahigh molecular weight polyethylene filter through a circulating water pump;

[0010] The purified water outputted by the ultra-high molecular weight polyethylene filter enters the hydraulic conveying rotor as backflushing water, and the dust-containing conveying water outputted by the ultra-high molecular weight polyethylene filter enters the hydraulic conveying rotor as conveying water, and the backflushing water entering the hydraulic conveying rotor has a higher pressure than the conveying water.

[0011] In some embodiments, a cooler is further arranged between the circulating water pump and the ultra-high molecular weight polyethylene filter.

[0012] In some embodiments, a pressure-reducing orifice is arranged on the dust-containing conveying water pipeline entering the hydraulic conveying rotor, so that the backflushing water has a higher pressure than the conveying water.

[0013] In some embodiments, the hydraulic conveying rotor comprises a particle inlet, a backflushing water inlet, a first conveying water inlet and a material outlet; the ultra-high molecular weight polyethylene filter comprises a dust-containing water inlet, a dust-containing water outlet and a purified water outlet.

[0014] The purified water outlet is communicated with the backflushing water inlet, and the dust-containing water outlet is communicated with the first conveying water inlet.

[0015] In some embodiments, the particle inlet of the hydraulic conveying rotor is communicated with an upstream steam method polypropylene VOC removal system, and the water-containing polypropylene particles enter the hydraulic conveying rotor through the particle inlet.

[0016] In some embodiments, the particle centrifugal dryer comprises a polypropylene particle inlet, a water outlet and a polypropylene particle outlet.

[0017] The polypropylene particle inlet is communicated with the material outlet of the hydraulic conveying rotor, and the polypropylene particle outlet is communicated with a downstream vibrating screening system.

[0018] In some embodiments, the circulating water tank comprises a second conveying water inlet, a first conveying water outlet and a dust-containing waste water outlet.

[0019] The second conveying water inlet is communicated with the water outlet of the particle centrifugal dryer, and the dust-containing waste water outlet is communicated with a waste water discharge system through a pipeline.

[0020] In some embodiments, the circulating water pump comprises a third conveying water inlet and a second conveying water outlet.

[0021] The third conveying water inlet is communicated with the first conveying water outlet of the circulating water tank.

[0022] In some embodiments, the cooler comprises a heat medium inlet, a heat medium outlet, a cooling water inlet and a cooling water outlet.

[0023] The cooling water inlet is connected with a utility circulating cooling water upper water system, and the cooling water outlet is connected with a utility circulating cooling water return water system.

[0024] A polypropylene particle hydraulic conveying method using the polypropylene particle hydraulic conveying system, characterized in that the method comprises the following steps:

[0025] The water-containing polypropylene particles enter the particle inlet of the hydraulic conveying feeder under the action of the rotation of the feeder rotor, are conveyed downward to the feeding pipe of the hydraulic conveying feeder, and are conveyed to the particle centrifugal dryer at a higher position by the dust-containing conveying water from the ultra-high molecular weight polyethylene filter.

[0026] After the conveying water and the polypropylene particles enter the particle centrifugal dryer, dehydration is performed by using a centrifugal force field and particle elastic impact, and the water droplets and a small amount of polypropylene fine powder carried by the polypropylene particles are discharged from the water outlet into the circulating water tank under the action of the centrifugal force, and the dried polypropylene particles are sent to a downstream vibrating screen system.

[0027] The conveying water from the particle centrifugal dryer is stored in the circulating water tank, the polypropylene fine powder with a smaller density than water floats on the upper surface of the water tank, and is overflowed and discharged from the dust-containing waste water outlet into a waste water discharge system together with the excess water, the conveying water is discharged from the circulating water tank conveying water outlet and is sent to the cooler by the circulating water pump, is cooled under the action of the circulating cooling water, and is then sent to the ultra-high molecular weight polyethylene filter.

[0028] After the conveying water enters the ultra-high molecular weight polyethylene filter, part of the dust-containing water penetrates from the inner surface to the outer surface of the filter pipe, a small amount of fine powder contained in the water is intercepted on the inner surface of the filter pipe, so that the part of the dust-containing water becomes purified water, and is discharged from the purified water outlet, and the part of the purified water enters the hydraulic conveying feeder as backflushing water after flow control.

[0029] Compared with the prior art, the polypropylene particle hydraulic conveying system has the following advantages and beneficial effects:

[0030] 1. The present application adopts hydraulic transportation to realize the transportation process of water-containing polypropylene particles to high-level equipment, solves the problem of water-containing polypropylene particle transportation, adopts a hydraulic transportation material transfer device, effectively prevents steam leakage loss in the VOC removal equipment, avoids the problem that a large amount of conveying water enters the upstream VOC removal equipment when the conveying water pressure is higher than the upstream VOC removal equipment, and thus the VOC removal equipment cannot work normally. The polypropylene particle hydraulic transportation system provided by the present application is related to a conveying and drying system of polypropylene after steam method VOC removal, and is also applicable to the field of hydraulic transportation of particle materials such as polyethylene and other materials with a density less than water.

[0031] 2. The present application adopts an ultrahigh molecular weight polyethylene filter with high filtration precision, small pressure drop and high passing rate. The purified water after filtration is sent into the material transfer device, and the purified water is used as backflushing water of the material transfer device. The backflushing water is used to flush the sealing structure, prevent fine powder from wearing the seal, prolong the service life of the material transfer device, push the polypropylene particles downward to take out the rotor of the material transfer device, and send the polypropylene particles into the feeding pipe.

[0032] 3. The hydraulic transportation material transfer device adopted by the present application requires that the backflushing water pressure is slightly higher than the conveying water pressure. Therefore, a pressure reducing orifice plate is arranged on the conveying water pipeline, so that the conveying water pressure is 0.05-0.1 MPa lower than the backflushing water pressure, and the normal use of the material transfer device is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1 It is a structural schematic view of the polypropylene particle hydraulic transportation system.

[0035] Among them:

[0036] 1. Hydraulic transportation material transfer device

[0037] 1-1. Water-containing polypropylene particle inlet

[0038] 1-2. Backflushing water inlet

[0039] 1-3. First conveying water inlet

[0040] 1-4. Material outlet

[0041] 2. Particle centrifugal dryer

[0042] 2-1. Particle inlet

[0043] 2-2. Drainage port

[0044] 2-3-particle outlet;

[0045] 3-circulating water tank;

[0046] 3-1-second water inlet;

[0047] 3-2-first water outlet;

[0048] 3-3-dirty water outlet;

[0049] 4-circulating water pump;

[0050] 4-1-third water inlet;

[0051] 4-2-second water outlet;

[0052] 5-cooler;

[0053] 5-1-heat medium inlet;

[0054] 5-2-heat medium outlet;

[0055] 5-3-cooling water inlet;

[0056] 5-4-cooling water outlet;

[0057] 6- ultra-high molecular weight polyethylene filter;

[0058] 6-1-dirty water inlet;

[0059] 6-2-dirty water outlet;

[0060] 6-3-clean water outlet. DETAILED DESCRIPTION

[0061] The technical solutions of the present application will be described in detail below with reference to the drawings and specific embodiments, so as to further understand the purposes, solutions and effects of the present application, but not as a limitation on the protection scope of the appended claims of the present application.

[0062] In the specification and subsequent claims, some words are used to refer to specific components or parts, and those skilled in the art should understand that the same component or part can be referred to by different names or terms by the user or manufacturer. The specification and subsequent claims do not distinguish components or parts by name, but by functional differences. In the entire specification and subsequent claims, "including" and "containing" are open terms, which should be interpreted as "including but not limited to". In addition, the term "connected" herein includes any direct and indirect electrical connection means. Indirect electrical connection means includes connection through other devices.

[0063] It should be noted that in the description of the present application, the terms "transverse", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and "about", or "approximately", "substantially", "left and right", etc. indicate the orientation or positional relationship or parameters, etc. based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, a particular size or be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0064] As shown in Figure 1 The polypropylene particle hydraulic conveying system provided by the embodiment of the present application comprises: a hydraulic conveying feeder 1; and a particle centrifugal dryer 2, which is in communication with the hydraulic conveying feeder 1; further comprising a circulating water tank 3, which is in communication with the particle centrifugal dryer 2; an ultra-high molecular weight polyethylene filter 6, which is in communication with the hydraulic conveying feeder 1; the circulating water tank 3 sends conveying water in the circulating water tank 3 to the ultra-high molecular weight polyethylene filter 6 through a circulating water pump 4;

[0065] The purified water output by the ultra-high molecular weight polyethylene filter 6 is used as backflushing water in the hydraulic conveying feeder 1, and the dust-containing conveying water is sent into the hydraulic conveying feeder 1 through a conveying pipe as conveying water, and the backflushing water pressure entering the hydraulic conveying feeder 1 is higher than the conveying water pressure. A cooler 5 is further arranged between the circulating water pump 4 and the ultra-high molecular weight polyethylene filter 6. Specifically, a pressure reduction orifice plate is arranged on the dust-containing conveying water pipe entering the hydraulic conveying feeder 1, so that the backflushing water pressure is higher than the conveying water pressure.

[0066] In the embodiment of the present application, the ultra-high molecular weight polyethylene filter is adopted, which has high filtering precision, small pressure drop and high passing rate. The purified water after filtration is sent into the feeder, and the purified water is used as backflushing water in the feeder. The function of the backflushing water is to flush the sealing structure and prevent the fine powder from wearing the sealing structure, thereby prolonging the service life of the feeder. At the same time, the polypropylene particles are pushed downward to be taken out of the feeder rotor and enter the feeding pipe. The hydraulic conveying feeder adopted requires that the backflushing water pressure is slightly higher than the conveying water pressure. Therefore, the pressure reduction orifice plate is arranged on the conveying water pipe, so that the conveying water pressure is 0.05-0.1 MPa (gauge pressure) lower than the backflushing water pressure, thereby ensuring the normal use of the feeder.

[0067] The water power conveying material changer 1 comprises a particle inlet 1-1, a backflushing water inlet 1-2, a first conveying water inlet 1-3 and a material outlet 1-4; the ultra-high molecular weight polyethylene filter 6 comprises a dust-containing water inlet 6-1, a dust-containing water outlet 6-2 and a purified water outlet 6-3; the filter core in the middle of the ultra-high molecular weight polyethylene filter 6 in the embodiment is an ultra-high molecular weight polyethylene sintered filter tube produced by the Shanghai Institute of Organic Chemistry of the Chinese Academy of Sciences, which has the characteristics of high filtering precision, large pass rate and low pressure drop. The filtering precision can be 0.22 μm-150 μm, and the preferred filtering precision is 10-50 μm; the water power conveying material changer 1 provided in the embodiment is a special equipment developed by the Tianhua Chemical Machinery and Automation Research and Design Institute, and the backflushing water pressure of the material changer is 0.05-0.1 MPa (gauge pressure) higher than the conveying water pressure to meet the requirements of material flushing and conveying.

[0068] The purified water outlet 6-3 is communicated with the backflushing water inlet 1-2, and the dust-containing water outlet 6-2 is communicated with the first conveying water inlet 1-3. The particle inlet 1-1 of the water power conveying material changer 1 is communicated with the upstream steam method polypropylene VOC removal system, and the water-containing polypropylene particles enter the water power conveying material changer 1 through the particle inlet 1-1.

[0069] The particle centrifugal dryer 2 comprises a polypropylene particle inlet 2-1, a drainage port 2-2 and a polypropylene particle outlet 2-3; the polypropylene particle inlet 2-1 is communicated with the material outlet 1-4 of the water power conveying material changer 1; and the polypropylene particle outlet 2-3 is communicated with the downstream vibrating screen separation system.

[0070] The circulating water tank 3 comprises a second conveying water inlet 3-1, a first conveying water outlet 3-2 and a dust-containing waste water outlet 3-3; the second conveying water inlet 3-1 is communicated with the drainage port 2-2 of the particle centrifugal dryer 2; and the dust-containing waste water outlet 3-3 is communicated with the waste water discharge system through a pipeline.

[0071] The circulating water pump 4 comprises a third conveying water inlet 4-1 and a second conveying water outlet 4-2;

[0072] The third conveying water inlet 4-1 is communicated with the first conveying water outlet 3-2 of the circulating water tank 3.

[0073] The cooler 5 comprises a heat medium inlet 5-1, a heat medium outlet 5-2, a cooling water inlet 5-3 and a cooling water outlet 5-4; the heat medium inlet 5-1 is communicated with the second water outlet 4-2 of the circulating water pump 4, the heat medium outlet 5-2 is communicated with the dust-containing water inlet 6-1 of the ultra-high molecular weight polypropylene filter 6, the cooling water inlet 5-3 is communicated with a public engineering circulating cooling water upper water system, and the cooling water outlet 5-4 is communicated with a public engineering circulating cooling water return water system.

[0074] Another embodiment of the present application provides a polypropylene particle hydraulic conveying method using the polypropylene particle hydraulic conveying system provided by the above-mentioned embodiments of the present application, comprising the following steps:

[0075] The temperature of the water-containing polypropylene particles is about 100-120℃, and the pressure is normal pressure or slightly positive pressure; the water-containing polypropylene particles enter the particle inlet 1-1 of the hydraulic conveying rotary feeder 1, and are conveyed downward to the feeding pipe under the action of the rotation of the rotor of the feeder; at this position, the dust-containing conveying water with a temperature of about 50-60℃ and a pressure of 0.2-0.8 MPa (gauge pressure) from the ultra-high molecular weight polyethylene filter 6 is conveyed to the particle centrifugal dryer 2 at a higher position; the polypropylene particles are cooled to 60-70℃ in the process of being mixed and conveyed with the water;

[0076] After the conveying water and the polypropylene particles enter the particle centrifugal dryer 2, dehydration is mainly carried out by using the centrifugal force field and the bouncing and impacting of the particles; the water droplets and a small amount of polypropylene fine powder carried by the polypropylene particles are discharged from the water outlet 2-2 into the circulating water tank 3 under the action of the centrifugal force; and the dried polypropylene particles are sent to the downstream vibrating screen system;

[0077] The conveying water with a temperature of about 60-70℃ from the particle centrifugal dryer 2 is stored in the circulating water tank 3; at this position, the polypropylene fine powder floats on the upper surface of the water tank due to the smaller density than the water, and is overflowed and discharged from the dust-containing waste water outlet 3-3 into the waste water discharge system together with the excess water; the conveying water is discharged from the circulating water outlet 3-2 of the circulating water tank 3, and is sent to the cooler 5 by the circulating water pump 4; and the conveying water is cooled under the action of the circulating cooling water, and enters the ultra-high molecular weight polyethylene filter 6 after being cooled to about 50-60℃;

[0078] After the conveying water enters the ultra-high molecular weight polyethylene filter 6, part of the dust-containing water penetrates from the inner surface to the outer surface of the filter pipe, and the small amount of fine powder contained in the water is intercepted on the inner surface of the filter pipe, so that the part of the dust-containing water becomes purified water, and is discharged from the purified water outlet 6-3; the part of the purified water enters the hydraulic conveying rotary feeder 1 after being controlled by the flow rate, and is used as backflushing water; the dust-containing conveying water which does not penetrate the filter pipe is discharged from the dust-containing water outlet 6-2, and is reduced in pressure after passing through the pressure reducing orifice plate, and then enters the conveying water inlet 1-3 of the hydraulic conveying rotary feeder 1; the pressure of the conveying water after passing through the pressure reducing orifice plate is 0.05-0.1 MPa (gauge pressure) lower than the pressure of the backflushing water.

[0079] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can use the disclosed technology to make changes or modifications as equivalent embodiments applied to other fields, but without departing from the technical solution of the present application. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application still falls within the protection scope of the present application.

Claims

1. A polypropylene particle hydraulic conveying system, comprising: a hydraulic conveying rotor; and a particle centrifugal dryer in communication with the hydraulic conveying rotor; characterized in that further comprising a circulating water tank in communication with the particle centrifugal dryer; an ultra-high molecular weight polyethylene filter in communication with the hydraulic conveying rotor; the circulating water tank conveying the circulating water tank conveying water into the ultra-high molecular weight polyethylene filter through a circulating water pump; wherein the purified water output from the ultra-high molecular weight polyethylene filter enters the hydraulic conveying rotor as backflushing water, and the dust-containing conveying water output enters the hydraulic conveying rotor through a conveying pipe as conveying water, the backflushing water pressure entering the hydraulic conveying rotor being higher than the conveying water pressure.

2. The polypropylene pellets hydraulic transport system of claim 1, wherein: a cooler is further arranged between the circulating water pump and the ultra-high molecular weight polyethylene filter.

3. A polypropylene pellets hydraulic transport system according to claim 1 or 2, characterized in that: a pressure reduction orifice is arranged on the dust-containing conveying water pipe entering the hydraulic conveying rotor, so that the backflushing water pressure is higher than the conveying water pressure.

4. The polypropylene pellets hydraulic transport system of claim 2, wherein: the hydraulic conveying rotor comprises a particle inlet, a backflushing water inlet, a first conveying water inlet, and a material outlet; the ultra-high molecular weight polyethylene filter comprises a dust-containing water inlet, a dust-containing water outlet, and a purified water outlet; wherein the purified water outlet is in communication with the backflushing water inlet, and the dust-containing water outlet is in communication with the first conveying water inlet.

5. The polypropylene pellets hydraulic transport system of claim 4, wherein: the particle inlet of the hydraulic conveying rotor is in communication with an upstream steam method polypropylene VOC removal system, and the water-containing polypropylene particles enter the hydraulic conveying rotor through the particle inlet.

6. The polypropylene pellets hydraulic transport system of claim 5, wherein: the particle centrifugal dryer comprises a polypropylene particle inlet, a water discharge outlet, and a polypropylene particle outlet; wherein the polypropylene particle inlet is in communication with the material outlet of the hydraulic conveying rotor, and the polypropylene particle outlet is in communication with a downstream vibrating screen separation system.

7. The polypropylene pellets hydraulic transport system of claim 6, wherein: the circulating water tank comprises a second conveying water inlet, a first conveying water outlet, and a dust-containing waste water outlet; wherein the second conveying water inlet is in communication with the water discharge outlet of the particle centrifugal dryer, and the dust-containing waste water outlet is in communication with a waste water discharge system through a pipe.

8. The polypropylene pellets hydraulic transport system of claim 7, wherein the circulating water pump comprises a third conveying water inlet and a second conveying water outlet; wherein the third conveying water inlet is in communication with the first conveying water outlet of the circulating water tank.

9. The polypropylene pellets hydraulic transport system of claim 8, wherein: the cooler comprises a heat medium inlet, a heat medium outlet, a cooling water inlet, and a cooling water outlet; wherein the heat medium inlet is in communication with the second conveying water outlet of the circulating water pump, the heat medium outlet is in communication with the dust-containing water inlet of the ultra-high molecular weight polyethylene filter, the cooling water inlet is in communication with a utility circulating cooling water supply system, and the cooling water outlet is in communication with a utility circulating cooling water return system.

10. A method of hydrotransporting polypropylene particles using the polypropylene particle hydrotransport system according to claim 1 or 2, characterized in that: comprising the following steps: water-containing polypropylene particles enter the hydraulic conveying rotor through the particle inlet, and are conveyed downward to the feeding pipe of the hydraulic conveying rotor under the rotation of the rotor, and are conveyed to the particle centrifugal dryer at a higher position by the dust-containing conveying water from the ultra-high molecular weight polyethylene filter. After the water and polypropylene particles are transported into the particle centrifugal dryer, dehydration is performed by using the centrifugal force field and the elastic impact of the particles. The water droplets and a small amount of polypropylene fine powder carried by the polypropylene particles are discharged from the drainage port into the circulating water tank under the action of the centrifugal force. The dried polypropylene particles are sent to the downstream vibrating screen separation system. The conveying water from the particle centrifugal dryer is stored in the circulating water tank. The polypropylene fine powder, which has a smaller density than water, floats on the upper surface of the water tank and is overflowed from the dust-containing wastewater outlet into the wastewater discharge system with the excess water. The conveying water is discharged from the circulating water tank conveying water outlet and is sent to the cooler by the circulating water pump. The conveying water is cooled under the action of the circulating cooling water and then enters the ultra-high molecular weight polyethylene filter. After the conveying water enters the ultra-high molecular weight polyethylene filter, part of the dust-containing water penetrates from the inner surface to the outer surface of the filter tube. A small amount of fine powder contained in the water is intercepted on the inner surface of the filter tube, so that the part of the dust-containing water becomes purified water and is discharged from the purified water outlet. The part of the purified water enters the hydraulic conveying rotary feeder as backflushing water after flow control. The dust-containing conveying water that does not penetrate the filter tube is discharged from the dust-containing water outlet and enters the conveying water inlet of the hydraulic conveying rotary feeder after being reduced in pressure by the pressure-reducing orifice plate.

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