Improved pressing exhaust device

Abstract

The utility model discloses an improved material pressing and exhausting device which comprises an extruder barrel, an extrusion screw is arranged in the extruder barrel, an exhausting main barrel is arranged on the side portion of the extruder barrel, a screw cavity communicated with the extruder barrel is formed in the exhausting main barrel, an exhausting sealing screw is arranged in the screw cavity, and an air outlet sealing screw is arranged in the exhausting sealing screw. A negative pressure pipe is arranged on one side of the exhaust main cylinder and creates relative negative pressure in the cavity of the screw. According to the improved material pressing and exhausting device, the exhausting sealing screw rod for preventing melt in the machine barrel from entering is arranged in the exhausting main barrel, in the normal working process, the melt is extruded into the machine barrel of an extruder through rotation of the exhausting sealing screw rod, and gas can move upwards from a gap of the exhausting sealing screw rod and is exhausted through the negative pressure pipe; compared with the prior art, the device adopts an active transportation mode, melt materials entering the exhaust main cylinder are pressed and fed back, and therefore good gas separation can be achieved, and blocking is effectively prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of screw extruders, in particular to an improved material pressing and exhausting device. Background Art

[0002] The screw extruder is composed of a screw, a barrel, a hopper, and a die. When the raw material is in operation, it is fed into the barrel. Under the action of the screw, the raw material is melted, compressed, the melt is decompressed, the gas in the melt expands, the bubbles burst and separate from the melt, and the exhaust is exhausted. After the exhaust, the material is sheared and homogenized again. The exhaust is achieved through the exhaust port on the barrel.

[0003] In the prior art, there is a new exhaust screw for PET exhaust injection molding machine disclosed in patent application number CN201620700504.9; and another one is an exhaust screw structure for plastic extruder disclosed in application number CN201720025776.8. Both of the above structures are improvements on the structure of the screw, so that the water vapor and oligomers mixed in the materials in the screw machine barrel are squeezed near the feed port and exhausted from the feed port; the defect is that the screw machine usually has a certain length. If the gas is not completely exhausted at the feed port, the gas will be brought to the middle or rear of the screw machine barrel, which makes it inconvenient to exhaust.

[0004] There is another improved patent, application number CN202022582617.2, which discloses an extruder screw barrel. The patent sets an exhaust seat on the upper part of the barrel. The problem it solves is that the traditional exhaust port is set above the barrel by drilling, and the molten material easily enters the exhaust port and accumulates at the exhaust port and is difficult to fall back into the barrel, resulting in blockage of the exhaust port. Although it is provided with a conical airway and the pressure block is pressed by a spring for sealing; however, since the material in the barrel has pressure, the pressure is to lift the pressure block, so that the material enters the airway and easily causes blockage; if the material is prevented from entering by increasing the pressure of the spring, it will inevitably cause the pressure block to be tightly pressed at the airway port, and it will not be able to play the role of exhaust.

[0005] In view of the above, it is necessary to propose an improved press material exhaust device to solve the above problems. Utility Model Content

[0006] The purpose of the utility model is to solve the above technical problems and to provide an improved material pressing exhaust device.

[0007] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: an improved material pressing and exhausting device, including an extruder barrel, an extrusion screw is arranged in the extruder barrel, an exhaust main cylinder is arranged on the side of the extruder barrel, a screw cavity connected to the extruder barrel is formed in the exhaust main cylinder, an exhaust sealing screw is arranged in the screw cavity, a negative pressure pipe is arranged on one side of the exhaust main cylinder, and the negative pressure pipe creates a relative negative pressure in the screw cavity.

[0008] Furthermore, the negative pressure pipe is connected to the upper part of the exhaust main cylinder, and a pressure gauge is provided on the negative pressure pipe.

[0009] Furthermore, a flange opening is provided at the end of the negative pressure pipe, a reducing flange is connected to the flange opening, a negative pressure pipe interface is threadedly connected to the end of the reducing flange, and the negative pressure pipe interface is used to connect a vacuum pump.

[0010] Furthermore, the exhaust sealing screw is a twin-screw structure, and the exhaust sealing screw comprises a first exhaust screw and a second exhaust screw, and the first exhaust screw and the second exhaust screw are meshed with each other.

[0011] Furthermore, a gear distribution box is provided on the upper part of the exhaust main cylinder, and a reduction motor is provided on the upper part of the gear distribution box. The reduction motor is connected to the input end of the gear distribution box, and the output end of the gear distribution box is connected to the first exhaust screw and the second exhaust screw.

[0012] Furthermore, a discharge pipe is provided on one side of the upper portion of the exhaust main cylinder.

[0013] Compared with the prior art, the beneficial effects of the utility model are as follows: an improved press-feed exhaust device of the utility model is provided with an exhaust sealing screw in the exhaust main cylinder to prevent the melt in the barrel from entering; during normal operation, the rotation of the exhaust sealing screw squeezes the melt into the extruder barrel, while the gas can move upward from the gap of the exhaust sealing screw and be discharged through the negative pressure pipe; compared with the prior art, the device adopts an active transport method to press the molten material entering the exhaust main cylinder back, thereby achieving good gas separation and effectively preventing blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of an improved material pressing and exhausting device of the utility model;

[0015] In the figure: 1. Extruder barrel; 2. Extrusion screw; 3. Exhaust main barrel; 4. Screw cavity; 5. Exhaust sealing screw; 6. Negative pressure pipe; 7. Pressure gauge; 8. Flange mouth; 9. Reducer flange; 10. Negative pressure pipe interface; 11. First exhaust screw; 12. Second exhaust screw; 13. Gear distribution box; 14. Reducer motor; 15. Discharge pipe. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0017] An improved press exhaust device, such as Figure 1 As shown, the extruder barrel 1 includes an extrusion screw 2. In actual use, the melt material mixed with air, water vapor or oligomer is transported from the feed port to the extruder barrel 1 by the extrusion screw 2. In order to facilitate the discharge of gas from the extruder barrel 1, it is necessary to provide an exhaust main cylinder 3 on the side of the extruder barrel 1. The usual arrangement is to arrange the exhaust main cylinder 3 above the extruder barrel 1 for exhaust. In this device, the exhaust main cylinder 3 can be arranged as Figure 1 As shown, it is arranged above the extruder barrel 1, and can also be arranged in other directions. The reason is that the exhaust device forms a screw cavity 4 connected to the extruder barrel 1 in the exhaust main cylinder 3, and an exhaust sealing screw 5 is rotatably connected in the screw cavity 4. In the traditional way, it is preferred to set the exhaust cylinder at the top, one is that the gas is more likely to gather at the top, and the other is to reduce the probability of the melt in the barrel entering the exhaust cylinder. After the improvement of the present device, it is not subject to the above conditions and can be set in various directions, which is more in line with the actual situation. Since the gas in the extruder barrel 1 is squeezed and squeezed, the gas moves in the low-pressure direction, not necessarily upward. Therefore, the present device can set the position of the exhaust main cylinder 3 according to the actual situation.

[0018] Since the exhaust device is provided with an actively rotating exhaust sealing screw 5 in the exhaust main barrel 3, and the conveying direction of the melt by the exhaust sealing screw 5 is directed to the extruder barrel 1, when the melt overflows into the exhaust main barrel 3, the melt is continuously sent back to the extruder barrel 1 through the conveying action of the exhaust sealing screw 5, and the gas entrained in the melt can pass through the exhaust main barrel 3 and be discharged. Specifically, in order to facilitate the discharge of air and water vapor mixed in the melt material and oligomers in the material, it is necessary to evacuate the inside of the exhaust main barrel 3. A negative pressure pipe 6 is provided on one side of the exhaust main barrel 3, and the negative pressure pipe 6 creates a relative negative pressure in the screw cavity 4; since the inside of the extruder barrel 1 is a melt with a certain pressure when the screw is extruded, the above-mentioned relative negative pressure should be at least lower than the pressure in the extruder barrel 1, and it can be understood that the greater the pressure difference between the upper part of the exhaust main barrel 3 and the extruder barrel 1, the easier it is to extract the gas.

[0019] Specifically, the negative pressure pipe 6 is connected and arranged on the upper part of the exhaust main cylinder 3, and a pressure gauge 7 is provided on the negative pressure pipe 6; in actual use, the pressure gauge 7 can be a negative pressure gauge. In order to facilitate the creation of negative pressure on the negative pressure pipe 6, a flange opening 8 is provided at the end of the negative pressure pipe 6, and a reducing flange 9 is connected to the flange opening 8. A negative pressure pipe interface 10 is screwed on the end of the reducing flange 9, and the negative pressure pipe interface 10 is used to connect a vacuum pump; in actual use, the vacuum pipe of the vacuum pump is connected to the negative pressure pipe interface 10, so that the negative pressure pipe 6 can be evacuated, and the internal pressure is displayed by the pressure gauge 7; when gas passes through the exhaust sealing screw 5, it can be discharged.

[0020] Specifically, the exhaust sealing screw 5 is a twin-screw structure, and the exhaust sealing screw 5 includes a first exhaust screw 11 and a second exhaust screw 12, and the first exhaust screw 11 and the second exhaust screw 12 are meshed with each other. When the melt overflows upward, it is pressed down by the two vertical first exhaust screws 11 and the second exhaust screw 12, which are meshed with each other in an arc shape, so that the two can clean each other and prevent the material from holding the screw and causing blockage; and air or impurities can be vacuumed and discharged through the exhaust sealing screw 5.

[0021] Furthermore, a gear distribution box 13 is provided on the upper part of the exhaust main barrel 3, and a reduction motor 14 is provided on the upper part of the gear distribution box 13. The reduction motor 14 is connected to the input end of the gear distribution box 13, and the output end of the gear distribution box 13 is connected to the first exhaust screw 11 and the second exhaust screw 12. In actual use, the reduction motor 14 drives the first exhaust screw 11 and the second exhaust screw 12 to rotate through the gear distribution box 13, and transports the melt toward the direction of the extruder barrel 1.

[0022] As an improvement, a discharge pipe 15 is further provided on one side of the upper part of the exhaust main tube 3; Figure 1 The circular tube shown by the dotted line in the middle can be actively discharged through the discharge pipe 15. It can be understood that the reduction motor 14 should be a motor with bidirectional rotation control. When it rotates forward, the material flow is controlled to point to the extruder barrel 1, and when it is reversed, the material flow is controlled to be away from the extruder barrel 1. If there is a slight blockage in the exhaust main tube 3, the reduction motor 14 can be controlled to reverse and the discharge pipe 15 can be opened at the same time, so that a part of the blocked material can be transported to the discharge pipe 15, so that the material blocking the pipeline can be directly discharged, and then the reduction motor 14 can be controlled to rotate forward to put it into normal operation.

[0023] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An improved press-feed exhaust device, comprising an extruder barrel (1), wherein an extrusion screw (2) is arranged in the extruder barrel (1), characterized in that: An exhaust main cylinder (3) is provided on the side of the extruder barrel (1), a screw cavity (4) connected to the extruder barrel (1) is formed in the exhaust main cylinder (3), an exhaust sealing screw (5) is provided in the screw cavity (4), and a negative pressure pipe (6) is provided on one side of the exhaust main cylinder (3), and the negative pressure pipe (6) creates a relative negative pressure in the screw cavity (4); The exhaust sealing screw (5) is a twin-screw structure with a mutual cleaning effect to prevent the material from holding the screw and causing blockage. The exhaust sealing screw (5) comprises a first exhaust screw (11) and a second exhaust screw (12), and the first exhaust screw (11) and the second exhaust screw (12) are meshed with each other. A gear distribution box (13) is provided on the upper part of the exhaust main cylinder (3), and a reduction motor (14) with bidirectional rotation control is provided on the upper part of the gear distribution box (13). A discharge pipe (15) is also provided on one side of the upper part of the exhaust main cylinder (3). When the reduction motor (14) rotates forward, the material flow direction is controlled to point to the extruder barrel (1), and when it rotates reversely, the material flow direction is controlled to be away from the extruder barrel (1), and the discharge pipe (15) is opened at the same time, so that a part of the blocked material is transported to the discharge pipe (15).

2. An improved press-feed exhaust device according to claim 1, characterized in that: The negative pressure pipe (6) is connected to the upper part of the exhaust main cylinder (3), and a pressure gauge (7) is provided on the negative pressure pipe (6).

3. The improved press-feed exhaust device according to claim 1 is characterized in that: The end of the negative pressure pipe (6) is provided with a flange opening (8), a reducing flange (9) is connected to the flange opening (8), a negative pressure pipe interface (10) is screwed to the end of the reducing flange (9), and the negative pressure pipe interface (10) is used to connect a vacuum pump.

4. The improved press-feed exhaust device according to claim 1, characterized in that: The reduction motor (14) is connected to the input end of the gear distribution box (13), and the output end of the gear distribution box (13) is connected to the first exhaust screw (11) and the second exhaust screw (12).

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