Lateral vacuumizing and exhausting extruder

Abstract

The utility model relates to the technical field of extruder exhaust devices, in particular to a lateral vacuumizing and exhausting extruder which comprises an extruder cylinder, an exhaust cylinder is arranged on one side of the extruder cylinder, a pair of parallel combined screws is rotatably connected in the exhaust cylinder, each combined screw comprises a first material returning portion, an exhausting portion and a second material returning portion, and the first material returning portion is provided with a plurality of exhaust holes. The first material returning part is arranged at the end, facing the extruder barrel, of the exhaust barrel, the rotation direction of the exhaust parts is opposite to the rotation direction of the first material returning part and the rotation direction of the second material returning part, and the gap between the exhaust parts of the pair of combined screws is larger than that of the first material returning part and the second material returning part; and a discharge port is formed in the bottom of the discharge part of the exhaust barrel. According to the utility model, the first material returning part is used for conveying most of materials which are diffused into the exhaust barrel and are not polluted back to the barrel of the extruder; the rotating directions of the discharging parts are opposite to those of the first material returning part and the second material returning part, and a gap between the two discharging parts is larger, so that polluted materials are discharged; and the second material returning part is used for returning the polluted materials to the discharging part.

Description

Technical Field

[0001] The utility model relates to the technical field of extruder exhaust devices, in particular to an extruder with lateral vacuum exhaust. Background Art

[0002] Extruder is one of the main equipment for polymer processing. Exhaust is often required in the process of polymer processing using an extruder. The sources of gas include air, moisture and residual solvents entrained by particles. These gases must be exhausted, otherwise the extruded products will have internal or surface defects such as air gaps, bubbles, scars, etc., and may also affect the physical and chemical properties. The lateral vacuum system is a commonly used exhaust system for extruders. It forcibly removes the gas generated during the extrusion process and returns the material through the screw to prevent the material from being brought out during the exhaust process. However, the existing lateral vacuum system has a single screw type and is usually only used for return material. Moreover, the farther the material is from the extruder barrel, the higher the risk of contamination during the return process. The existing screw often returns the contaminated material to the extruder barrel, affecting the quality of the extruded product. Utility Model Content

[0003] Aiming at the problem that the screw in the existing lateral vacuum pumping system is of a single type and the contaminated materials are often sent back to the barrel of the extruder, the utility model provides an extruder with lateral vacuum pumping and exhaust.

[0004] The utility model provides the following technical solution: a side vacuum exhaust extruder, comprising an extruder barrel, an exhaust barrel being arranged on one side of the extruder barrel, the inner cavity of the exhaust barrel being communicated with the inner cavity of the extruder barrel, a pair of parallel combined screws being rotatably connected to the exhaust barrel, the combined screw comprising a first return part, a discharge part and a second return part, the first return part being arranged at one end of the exhaust barrel facing the extruder barrel, the rotation direction of the discharge part being opposite to those of the first return part and the second return part, and the gap between the discharge parts of a pair of combined screws being larger than the first return part and the second return part; the exhaust barrel is provided with a discharge port at the bottom of the discharge part.

[0005] Preferably, a transition portion is provided between the first material return portion and the discharge portion, and the transition portion has the same outer diameter as the first material return portion and an opposite rotation direction.

[0006] Preferably, the length of the transition portion is 20-30% of the length of the first return portion.

[0007] Preferably, the exhaust cylinder is provided with an exhaust port at the top of the discharge portion, the exhaust port is provided with an exhaust chamber, and the discharge port is provided with a discharge chamber.

[0008] The beneficial effects of the present utility model are as follows: A combined screw is adopted, which includes a first material return part, a discharge part, and a second material return part; the first material return part sends most of the materials that diffuse into the exhaust cylinder body and are not contaminated back to the extrusion machine cylinder body; the spiral direction of the discharge part is opposite to that of the first and second material return parts, and the gap between the two discharge parts is also larger to discharge the contaminated materials; the second material return part sends the contaminated materials back to the discharge part. Description of the Drawings

[0009] Figure 1 It is a sectional view of an embodiment of an extruder.

[0010] Figure 2 It is a top view of an embodiment of the combined screw.

[0011] Reference Signs: 10, extrusion machine cylinder body; 20, exhaust cylinder body; 21, exhaust port; 22, discharge port; 30, combined screw; 31, first material return part; 32, discharge part; 33, second material return part; 34, transition part; 40, exhaust chamber; 50, discharge chamber. Detailed Embodiments

[0012] The following further describes the embodiments of the present utility model in detail with reference to the drawings and reference signs, so that those skilled in the art can implement it after studying this specification. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0013] An extruder with a lateral vacuum pumping system generally includes an extrusion machine cylinder body 10, an exhaust cylinder body 20 is arranged on one side of the extrusion machine cylinder body 10, the inner cavity of the exhaust cylinder body 20 is communicated with the inner cavity of the extrusion machine cylinder body 10, and a pair of parallel screws are rotatably connected in the exhaust cylinder body 20, and the materials diffused into the exhaust cylinder body 20 are sent back into the extrusion machine cylinder body 10 by the rotation of the screws.

[0014] On the basis of the prior art, the present utility model provides an extruder with lateral vacuum exhaust, and the screw is a combined screw 30. Please refer to Figure 1 、 2, the combined screw 30 includes a first return part 31, a discharge part 32 and a second return part 33, which are sequentially connected along the axial direction of the combined screw 30. The first return part 31 is arranged at one end of the exhaust cylinder body 20 facing the extruder cylinder body 10. The first return part 31 sends most of the materials diffused into the exhaust cylinder body 20 and not contaminated back to the extruder cylinder body 10, and a small part of the materials will still continue to diffuse along the exhaust cylinder body 20 to the discharge part 32. At this time, the materials have been contaminated and cannot be sent back to the extruder cylinder body 10. Therefore, the helix direction of the discharge part 32 is opposite to that of the first return part 31. The exhaust cylinder body 20 is provided with a discharge port 22 at the bottom of the discharge part 32, and the discharge port 22 is provided with a discharge chamber 50. The discharge part 32 conveys the contaminated materials in a direction away from the extruder cylinder body 10 until they are discharged from the discharge port 22 into the discharge chamber 50; further, the gap between the discharge parts 32 of a pair of the combined screws is larger than the gap between the two first return parts 31, which is convenient for the discharge of the materials. A second return part 33 is further arranged at the end of the discharge part 32. The helix direction of the second return part 33 is opposite to that of the discharge part 32, and the gap between the two second return parts 33 is larger than the gap between the two discharge parts 32, and the materials diffused to the second return part 33 are sent back to the discharge part 32 and the discharge port 22. The exhaust cylinder body 20 is provided with an exhaust port 21 at the top of the discharge part 32, and the exhaust port 21 is provided with an exhaust chamber 40. The gas generated by the extruder cylinder body 10 is discharged through the exhaust chamber 40.

[0015] Preferably, a transition part 34 is arranged between the first return part 31 and the discharge part 32. The transition part 34 has the same outer diameter as the first return part 31 and the opposite helix direction, reducing the risk of the contaminated materials being sent back to the extruder cylinder body 10. The length of the transition part 34 is 20% - 30% of that of the first return part 31.

[0016] The above are one or more embodiments of the present invention, and the description thereof is relatively specific and detailed, but it should not be understood as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A side vacuum exhaust extruder, comprising an extruder barrel, a side of which is provided with an exhaust barrel, the inner cavity of the exhaust barrel is connected to the inner cavity of the extruder barrel, and a pair of parallel assembled screws are rotatably connected to the exhaust barrel, characterized in that: The combined screw comprises a first return portion, a discharge portion and a second return portion, wherein the first return portion is arranged at one end of the exhaust cylinder facing the extruder cylinder, the rotation direction of the discharge portion is opposite to the first return portion and the second return portion, and the gap between the discharge portions of a pair of combined screws is larger than the first return portion and the second return portion; the exhaust cylinder is provided with a discharge port at the bottom of the discharge portion.

2. A side vacuum exhaust extruder according to claim 1, characterized in that: A transition portion is provided between the first material return portion and the discharge portion. The transition portion has the same outer diameter as the first material return portion and has an opposite rotation direction.

3. A side vacuum exhaust extruder according to claim 2, characterized in that: The length of the transition portion is 20-30% of the first return portion.

4. A side vacuum exhaust extruder according to claim 1, characterized in that: The exhaust cylinder is provided with an exhaust port at the top of the discharge portion, the exhaust port is provided with an exhaust chamber, and the discharge port is provided with a discharge chamber.

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