CN215849561U

CN215849561U - Vacuum system of double-screw extruder

Info

Publication number: CN215849561U
Application number: CN202122391596.0U
Authority: CN
Inventors: 周永南; 庞泽涛; 盛增; 李义邦; 解玉柱
Original assignee: Jiangsu Huizhi New Material Technology Co ltd
Current assignee: Jiangsu Huizhi New Material Technology Co ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-02-18
Anticipated expiration: 2031-09-30

Abstract

The utility model discloses a vacuum system of a double-screw extruder, which comprises a vacuum device and a vacuum pipeline connected between an exhaust port of the double-screw extruder and the vacuum device, wherein heating jackets are arranged on the peripheries of the vacuum pipeline and a connecting end, and a medium cavity of each heating jacket is surrounded on the outer peripheral walls of the vacuum pipeline and the connecting end; the heating device also comprises a heating medium and a medium circulation loop, and the medium cavity is communicated with the medium circulation loop. This double screw extruder's vacuum system is rational in infrastructure, and vacuum pipe and link periphery all are provided with the heating jacket, through enclosing the medium chamber of locating vacuum pipe and link periphery wall, and with heating medium's medium circulation loop intercommunication, effectively solved in the vacuum pipe and the problem that the mouth of pipe link blocks up vacuum pipe because of polymer oligomer condensation residue to improve the utilization ratio of the medium energy and the rational utilization of medium resource, reached energy-concerving and environment-protective effect.

Description

Vacuum system of double-screw extruder

Technical Field

The utility model relates to the technical field of double-screw extruders, in particular to a vacuum system of a double-screw extruder.

Background

The double-screw extruder is common extrusion equipment and is widely applied to the fields of filling, blending, modification and the like of rubber and engineering resin. Rubber and engineering resin raw materials are not dried and dedusted before entering a double-screw extruder for melt extrusion, and the raw materials can generate a large amount of high molecular oligomers, moisture and impurities during high-temperature melting, so that hydrolysis and paste generation of the raw materials in a high-temperature melting state can be caused if the raw materials are not removed in time, and the quality of products is influenced. In the existing online screw production line, a vacuum system is used for discharging water vapor and high molecular oligomers in production and processing engineering, and the vacuum system of a double-screw extruder mainly comprises a vacuum pipeline and a vacuum device. In the production, a part of the high molecular oligomer and water are discharged in the form of gas, and the other part of the high molecular oligomer and water are solidified by condensation and remain in the vacuum pipeline and the vacuum device. Excessive accumulation of residues affects the vacuumizing effect, and further affects the quality of products; the machine needs to be stopped for cleaning, and the pipeline is difficult to clean due to small space and long in disassembly and cleaning. Therefore, the removal of condensation residues inside the vacuum line and in the vacuum device is a problem that the skilled person needs to solve.

In the prior art, publication number CN212498891U discloses a vacuum exhaust system of an extruder, which comprises an exhaust pipe communicated with an exhaust port of the extruder, wherein the other end of the exhaust pipe is communicated with an oil-gas separator through a vacuum device, a heat exchanger is arranged outside the vacuum device, cold water of the heat exchanger is sent into the vacuum device and enters the oil-gas separator together with oil gas, and hot water separated in the oil-gas separator is sent into the heat exchanger; the exhaust pipe is sleeved with a heating ring, and a heating control box for controlling the heating ring is arranged outside the exhaust pipe.

Publication No. CN206426440U discloses an improved vacuum-pumping system of an extruder, which comprises a vacuum component and a vacuum-pumping section located at the rear end of a screw cylinder of the extruder, wherein a vacuum chamber is arranged at the top of a pumping-out opening of the vacuum-pumping section, a vacuum-pumping pipe is configured at the pumping-out opening of the vacuum chamber, and the outer wall of the vacuum pipe is wrapped with a heating sleeve; the vacuum assembly comprises a vacuum device, a vacuum tank and water, and the outer wall of the vacuum tank is wrapped with a heating sleeve.

Publication No. CN207736717U discloses a twin-screw extruder vacuum system, which comprises a first pipeline connected with the twin-screw extruder, a roots pump communicated with the first pipeline, and a screw pump vacuum unit; the screw pump vacuum unit comprises a screw pump with a cavity, a screw pump cooling device, a cleaning tank for containing cleaning liquid and a central control device.

The prior art has the defects that:

the heating sleeve which is electrically heated is arranged on the outer wall of the vacuum tube in a surrounding manner, so that the problem of residue condensation in the vacuum tube is solved, but gas in the vacuum tube is easy to condense and deposit at the connecting end parts at the two ends of the vacuum tube, so that the vacuum tube is blocked, and the subsequent vacuum tube is not convenient to disassemble, maintain or further clean; the heating sleeve needs to be electrified to heat the heating ring or the heating wire firstly and then transfer heat to heat the vacuum tube of the heated body, the heat source is not fully contacted with the heated body, the temperature of the heating ring or the heating wire is different from the transmitted temperature, the energy consumption is often caused, and the energy utilization rate is insufficient.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art and provides a vacuum system of a double-screw extruder.

In order to achieve the technical effects, the technical scheme of the utility model is as follows: a vacuum system of a double-screw extruder comprises a vacuum device and a vacuum pipeline connected between an exhaust port of the double-screw extruder and the vacuum device, wherein heating jackets are arranged on the peripheries of the vacuum pipeline and a connecting end, and a medium cavity of each heating jacket is arranged on the peripheral walls of the vacuum pipeline and the connecting end in a surrounding manner; the heating device also comprises a heating medium and a medium circulation loop, and the medium cavity is communicated with the medium circulation loop.

In order to enhance the sealing performance and the stability of the connecting end, the connecting end is further in flange connection.

In order to improve the utilization rate of energy, realize the energy-saving effect, optimize the medium circulation loop, the preferred technical scheme is: the medium circulation loop comprises a medium heating circulation pipeline, a melt filter is arranged at an extrusion port of the double-screw extruder, and the melt filter and the heating jacket are connected in parallel or in series with the medium heating circulation pipeline to form the medium circulation loop. In order to optimize the medium quality in the medium circulation loop, reduce the heating power of the heating medium and realize further energy-saving effect, the melt filter and the heating jacket are further connected with the medium heating circulation pipeline in series. The heating medium is hot fluid, and the fluid medium with the corresponding temperature is selected according to the temperature required by the melting of the actual extrusion material.

In order to prevent that there is great difference in temperature polymer oligomer to meet the condensation knot in the twin-screw extruder with the exhaust port department of twin-screw extruder, be unfavorable for the quick gas escape of polymer oligomer and moisture, lead to the connection end of vacuum pipe and twin-screw extruder gas vent to be connected to block up, influence vacuum system's vacuum, preferred technical scheme is: the heating jacket is provided with a medium feeding hole and a medium discharging hole which are communicated with the medium cavity, the medium feeding hole is formed in the connecting end portion of the vacuum pipeline and the double-screw extruder, the connecting end portion is connected with the exhaust port of the double-screw extruder, and the medium discharging hole is formed in the other connecting end portion of the vacuum pipeline.

In order to further preserve heat and reduce heat loss, the preferable technical scheme is as follows: and the outer wall of the heating jacket is provided with a heat insulation sleeve.

In order to reduce the condensation and precipitation of the high molecular oligomer in the vacuum device and influence the vacuum degree of the vacuum system, the preferable technical scheme is as follows: and a micro dust separator is also arranged between the vacuum pipeline and the vacuum device.

In order to further realize the rapid discharge of water and high molecular oligomers in the double-screw extruder, improve the quality of extruded products and realize the maintenance or further cleaning of a vacuum system in a non-stop state, the preferred technical scheme is as follows: the double-screw extruder is provided with at least two exhaust ports which are respectively connected with a vacuum pipeline, the exhaust ports are sequentially arranged along the axial direction of the double-screw extruder, and intervals are arranged among the exhaust ports. Further, the exhaust port is arranged in the middle of the machine barrel of the double-screw extruder.

In order to further optimize the pipeline connecting the dust particle separator with the vacuum pipeline and the vacuum device and effectively control the vacuum degree of the vacuum system, the preferable technical proposal is as follows: the device comprises a vacuum device, a dust separator, a manifold vacuum electromagnetic valve, a branch pipe vacuum electromagnetic valve, a manifold vacuum manifold, a manifold vacuum electromagnetic valve, a manifold vacuum manifold, a manifold vacuum manifold, a manifold vacuum manifold, a manifold vacuum manifold, a manifold.

In order to realize higher vacuum degree in the double-screw vacuum system, the preferable technical scheme is as follows: the vacuum device comprises a preceding stage vacuum pump, a vacuum pump and a gas-liquid separator, wherein an air inlet pipeline of the vacuum pump is communicated with a cleaning pipeline, the cleaning pipeline is communicated with the cooling and cleaning device, and the preceding stage vacuum pump and the gas-liquid separator form a circulation loop. Furthermore, the backing vacuum pump is a water ring vacuum pump. Further, the vacuum pump is a roots pump.

In order to prevent the high molecular oligomer and impurities from remaining on the rotors in the foreline vacuum pump and the vacuum pump, increase the load of the foreline vacuum pump and the vacuum pump, so as to avoid influencing the service life and normal use of the foreline vacuum pump and the vacuum pump, and further cool the foreline vacuum pump and the vacuum pump, the preferable technical proposal is as follows: the vacuum pump comprises a primary vacuum pump and a secondary vacuum pump which are connected in series, the cleaning pipeline comprises a branch cleaning pipeline with the same stage number as the vacuum pump, the air inlet pipelines of the primary vacuum pump and the secondary vacuum pump are communicated with the branch cleaning pipelines in a one-to-one correspondence mode, and the branch cleaning pipelines are respectively provided with branch cleaning electromagnetic valves. In order to prevent the cleaning liquid from blocking the pipeline due to carbon deposition when meeting high temperature, the cleaning liquid in the cooling and cleaning device is white mineral oil.

The utility model has the advantages and beneficial effects that:

this double screw extruder's vacuum system is rational in infrastructure, and vacuum pipe and link periphery all are provided with the heating jacket, through enclosing the medium chamber of locating vacuum pipe and link periphery wall, and with heating medium's medium circulation loop intercommunication, effectively solved in the vacuum pipe and the problem that the mouth of pipe link blocks up vacuum pipe because of polymer oligomer condensation residue to improve the utilization ratio of the medium energy and the rational utilization of medium resource, reached energy-concerving and environment-protective effect.

Drawings

Fig. 1 is a cross-sectional view of a vacuum system vacuum line and a heating jacket of the utility model twin-screw extruder;

FIG. 2 is a schematic structural view of embodiment 1 of a vacuum system of the twin-screw extruder of the utility model;

fig. 3 is a schematic structural view of embodiment 2 of the vacuum system of the twin-screw extruder of the utility model.

In the figure, 1, a vacuum pipeline; 2. a fine dust separator; 3. a medium heating circulation line; 4. a vacuum pump; 5. cleaning the tank; 6. a gas-liquid separator; 1-A, a first vacuum pipeline; 1-B, a second vacuum pipeline; 2-A, a first dust separator; 2-B, a second dust separator; 10. a twin screw extruder; 11. a melt filter; 12. a heating jacket; 13. a media chamber; 14. a thermal insulation sleeve; 15. a connecting end; 1-a, a medium feed port; 1-b, a medium discharge port; 21. branch pipe vacuum solenoid valves; 22. an exhaust branch pipe; 23. a main vacuum solenoid valve; 24. a vacuum manifold; 30. heating the circulating pump; 31. a medium discharge line; 32. a medium return line; 4. a vacuum pump; 41. a primary vacuum pump; 42. a secondary vacuum pump; 43. a backing vacuum pump; 50. cleaning a pipeline; 51. cleaning a pipeline by a first branch; 52. a second branch cleaning pipeline; 53. the branch cleaning solenoid valve.

Detailed Description

The following describes the embodiments of the present invention with reference to the examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Example 1

As shown in fig. 1-2, the vacuum system of the twin-screw extruder comprises a vacuum device and a vacuum pipeline 1 connected between an exhaust port of the twin-screw extruder 10 and the vacuum device, heating jackets 12 are arranged on the peripheries of the vacuum pipeline 1 and the connecting end 15, a medium cavity 13 of the heating jacket 12 is arranged around the peripheral walls of the vacuum pipeline 1 and the connecting end 15, and a heat-insulating sleeve 14 is arranged on the outer wall of the heating jacket 12; the heating jacket 12 is provided with a medium feed port 1-a and a medium discharge port 1-b which are communicated with the medium cavity 13, the medium feed port 1-a is arranged at the connecting end part of the vacuum pipeline 1 connected with the exhaust port of the double-screw extruder 10, and the medium discharge port 1-b is arranged at the other connecting end part of the vacuum pipeline 1; also included are a heating medium and a medium circulation loop, with which the medium chamber 13 communicates. The heating medium is hot oil.

The medium circulation loop comprises a medium heating circulation pipeline 3, a melt filter 11 is arranged at an extrusion port of the double-screw extruder 10, and the melt filter 11 and a heating jacket 12 are connected with the medium heating circulation pipeline 3 in parallel to form the medium circulation loop. The medium heating circulation pipeline 3 comprises a heating circulation pump 30, a medium discharge pipeline 31 and a medium return pipeline 32, the medium discharge pipeline 31 comprises a branch medium discharge pipeline, the melt filter 11 and the medium feed port 1-a are respectively communicated with the branch medium discharge pipeline, and the medium discharge port 1-b is communicated with the medium return pipeline 32.

A micro dust separator 2 is also arranged between the vacuum pipeline 1 and the vacuum device.

The vacuum device comprises a preceding stage vacuum pump 43, a vacuum pump 4 and a gas-liquid separator 6, wherein the preceding stage vacuum pump 43 is a water ring vacuum pump, and the vacuum pump 4 is a roots pump; the air inlet pipeline of the Roots pump is communicated with a cleaning pipeline 50, the cleaning pipeline 50 is communicated with the cooling and cleaning device 5, and the water ring vacuum pump and the gas-liquid separator 6 form a circulation loop. The cleaning liquid in the cooling and cleaning device 5 is white mineral oil.

Example 2

As shown in fig. 3, the vacuum system of the twin-screw extruder 10 includes a vacuum device, and a vacuum pipe 1 connected between the exhaust ports of the twin-screw extruder 10 and the vacuum device, the twin-screw extruder 10 is provided with two exhaust ports, which are respectively connected with the vacuum pipe 1, the exhaust ports are sequentially arranged along the axial direction of the twin-screw extruder, a gap is provided between the exhaust ports, and the exhaust ports are arranged in the middle of the barrel of the twin-screw extruder 10. Heating jackets 12 are arranged on the peripheries of the vacuum pipeline 1 and the connecting end 15, a medium cavity 13 of each heating jacket 12 is arranged on the peripheral walls of the vacuum pipeline 1 and the connecting end 15 in a surrounding manner, and a heat-insulating sleeve 14 is arranged on the outer wall of each heating jacket 12; the heating jacket 12 is provided with a medium feed port 1-a and a medium discharge port 1-b which are communicated with the medium cavity 13, the medium feed port 1-a is arranged at the connecting end part of the vacuum pipeline 1 connected with the exhaust port of the double-screw extruder 10, and the medium discharge port 1-b is arranged at the other connecting end part of the vacuum pipeline 1; the heating device also comprises a heating medium and a medium circulation loop, and the medium cavity is communicated with the medium circulation loop. The heating medium is hot oil.

The medium circulation loop comprises a medium heating circulation pipeline 3, a melt filter 11 is arranged at an extrusion port of the double-screw extruder 10, and the melt filter 11 and a heating jacket 12 are connected with the medium heating circulation pipeline 3 in series. The medium heating circulation pipeline 3 comprises a heating circulation pump 30, a medium discharge pipeline 31 and a medium return pipeline 32, the medium is heated by the heating circulation pump 30 into a heating medium, flows out of the medium discharge pipeline 31, passes through the melt filter 11 and the heating jacket 12, and returns back to the medium through the medium return pipeline 32 to form a medium circulation loop connected in series.

A micro dust separator 2 is also arranged between the vacuum pipeline 1 and the vacuum device; the number of the vacuum pipelines 1 is the same as that of the dust particle separators 2, branch vacuum electromagnetic valves 21 are respectively arranged on exhaust branch pipes 22 of the dust particle separators 2, the exhaust branch pipes 22 are communicated with a vacuum main pipe 24 of a vacuum device, and a main vacuum electromagnetic valve 23 is arranged on the vacuum main pipe 24. The vacuum pipeline 1 comprises a first vacuum pipeline 1-A and a second vacuum pipeline 1-B, the dust separator 2 comprises a first dust separator 2-A and a second dust separator 2-B, and the first vacuum pipeline 1-A and the second vacuum pipeline 1-B are respectively arranged corresponding to the first dust separator 2-A and the second dust separator 2-B.

The vacuum device comprises a water ring vacuum pump, a roots pump and a gas-liquid separator, the roots pump comprises a first-stage roots pump and a second-stage roots pump which are connected in series, the cleaning pipeline 50 comprises a cleaning pipeline 51 and a second branch cleaning pipeline 52, the air inlet pipeline of the first-stage roots pump and the second-stage roots pump is respectively communicated with the first branch cleaning pipeline 51 and the second branch cleaning pipeline 52 correspondingly, and branch cleaning electromagnetic valves 53 are respectively arranged on the first branch cleaning pipeline 51 and the second branch cleaning pipeline 52. The first branch cleaning pipeline 51 and the second branch cleaning pipeline 52 are both communicated with the cooling and cleaning device 5, the water ring vacuum pump and the gas-liquid separator 6 form a circulating loop, and cleaning liquid in the cooling and cleaning device 5 is white mineral oil.

Example 2 process for using vacuum system of twin screw extruder 10, when twin screw extruder 10 is in on-line production, the vacuum system discharges water vapor and high molecular oligomer which are generated in the production process, the high molecular oligomer and water are discharged in gas form from two exhaust ports of twin screw extruder 10, and pass through first vacuum pipeline 1-a and second vacuum pipeline 1-B which are connected respectively. Heating jackets 12 are respectively arranged on the peripheries of the first vacuum pipeline 1-A, the second vacuum pipeline 1-B and the connecting end 15, a melt filter 11 is arranged at an extrusion port of the double-screw extruder 10, medium oil is heated into hot oil by a heating circulating pump 30, flows out of a medium discharge pipeline 31, passes through the melt filter 11 and the heating jackets 12, and flows back by a medium return pipeline 32 to form a medium circulating loop connected in series; hot oil flows in from a medium inlet 1-a communicated with the medium cavity 13, is in full contact with the outer walls of the first vacuum pipeline 1-A and the second vacuum pipeline 1-B for heat transfer, and then flows out from a medium outlet 1-B. The water vapor and the high molecular oligomer gas are heated to keep a gas state, and the gas state is maintained by the first dust separator 2-A and the second dust separator 2-B which are respectively and correspondingly connected with the first vacuum pipeline 1-A and the second vacuum pipeline 1-B, and the vacuum gas flow in the first vacuum pipeline 1-A and the second vacuum pipeline 1-B is adjusted by utilizing branch vacuum electromagnetic valves 21 respectively arranged on exhaust branch pipes 22 of the first dust separator 2-A and the second dust separator 2-B, the exhaust branch pipes 22 are communicated with a vacuum main pipe 24 of a vacuum device, and the main vacuum electromagnetic valve 23 arranged on the vacuum main pipe 24 is used for controlling the total vacuum gas flow of a vacuum system. The high molecular oligomer and the moisture gas sequentially pass through a first-stage lobe pump and a second-stage lobe pump which are connected in series, a water ring vacuum pump and a gas-liquid separator 6, and waste gas and waste liquid are discharged.

One-level roots pump, second grade roots pump and water ring vacuum pump operate for a long time and heat up, and a small amount of polymer oligomer condenses on the rotor, and pump body load power is lower, washs solenoid valve 53 through the branch road that sets up respectively on first branch road washing pipeline 51 and the second branch road washing pipeline 52, cools off the washing pump body respectively, improves production efficiency.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A vacuum system of a double-screw extruder comprises a vacuum device and a vacuum pipeline (1) connected between an exhaust port of the double-screw extruder (10) and the vacuum device, and is characterized in that heating jackets (12) are arranged on the peripheries of the vacuum pipeline (1) and a connecting end (15), and a medium cavity (13) of each heating jacket (12) is arranged on the peripheral walls of the vacuum pipeline (1) and the connecting end (15) in a surrounding manner; the heating device also comprises a heating medium and a medium circulation loop, and the medium cavity (13) is communicated with the medium circulation loop.

2. The vacuum system of a twin-screw extruder according to claim 1, characterized in that the medium circulation loop comprises a medium heating circulation line (3), the extrusion opening of the twin-screw extruder (10) is provided with a melt filter (11), and the melt filter (11) and a heating jacket (12) are connected in parallel or in series with the medium heating circulation line (3) to form the medium circulation loop.

3. The vacuum system of the twin-screw extruder according to claim 1 or 2, characterized in that the heating jacket (12) is provided with a medium feed port (1-a) and a medium discharge port (1-b) which are communicated with the medium chamber (13), the medium feed port (1-a) is provided at the connection end of the vacuum pipe (1) connected with the exhaust port of the twin-screw extruder (10), and the medium discharge port (1-b) is provided at the other connection end of the vacuum pipe (1).

4. Vacuum system of a twin-screw extruder according to claim 1, characterised in that the outer wall of the heating jacket (12) is provided with a thermal jacket (14).

5. The vacuum system of a twin-screw extruder according to claim 1, characterized in that a fine dust separator (2) is further arranged between the vacuum pipe (1) and the vacuum device.

6. The vacuum system of a twin-screw extruder according to claim 5, wherein the twin-screw extruder (10) is provided with at least two exhaust ports to which vacuum pipes (1) are respectively connected, the exhaust ports being arranged in sequence in the axial direction of the twin-screw extruder (10), and spaces being provided between the exhaust ports.

7. The vacuum system of the twin-screw extruder of claim 6, wherein the number of the vacuum pipes (1) is the same as that of the dust separators (2), the vacuum pipes (1) and the dust separators (2) are arranged in a one-to-one correspondence manner, branch vacuum solenoid valves (21) are respectively arranged on exhaust branch pipes (22) of the dust separators (2), the exhaust branch pipes (22) are communicated with a vacuum main pipe (24) of the vacuum device, and a main vacuum solenoid valve (23) is arranged on the vacuum main pipe (24).

8. The vacuum system of a twin-screw extruder according to claim 1, characterized in that the vacuum device comprises a foreline vacuum pump (43), a vacuum pump (4) and a gas-liquid separator (6), the air inlet line of the vacuum pump (4) is communicated with a cleaning line (50), the cleaning line (50) is communicated with a cooling and cleaning device (5), and the foreline vacuum pump (43) and the gas-liquid separator (6) form a circulation loop.

9. The vacuum system of the twin-screw extruder of claim 8, wherein the vacuum pump (4) comprises a primary vacuum pump (41) and a secondary vacuum pump (42) which are connected in series, the cleaning pipeline (50) comprises branch cleaning pipelines with the same number of stages as the vacuum pump (4), the air inlet pipelines of the primary vacuum pump (41) and the secondary vacuum pump (42) are respectively communicated with the branch cleaning pipelines in a one-to-one correspondence manner, and the branch cleaning pipelines are respectively provided with branch cleaning electromagnetic valves (53).