A batching premixing device for TPU plastic pellet production

Abstract

The present invention relates to the field of TPU processing technology, and more specifically, to a premixing device for producing TPU plastic pellets. The premixing device comprises a premixing tank, a top cover, and a stirring shaft rotatably disposed within the premixing tank, wherein the outer ring of the stirring shaft is provided with a stirring plate; a partition and a blocking member are disposed within the premixing tank, wherein the blocking member is sleeved on the outer ring of the stirring shaft and extends through the partition; and a driving mechanism is further provided, wherein the driving mechanism is configured to drive the partition or blocking member to move along the axial direction of the stirring shaft to lower the height of the raw material on the top of the partition, thereby exposing the raw material attached to the inner wall of the premixing tank. In the premixing device for producing TPU plastic pellets, the raw material attached to the inner wall of the premixing tank is exposed by adjusting the height of the partition or reducing the volume of the raw material on the top of the partition. The raw material is then flung toward the exposed portion in conjunction with a flow guide, causing the exposed portion to be impacted by the raw material, thereby achieving stirring and mixing of the attached raw material.

Description

Technical Field

[0001] The invention relates to the technical field of TPU processing, in particular to a batching premixing device for producing TPU plastic particles. Background Art

[0002] In the TPU (thermoplastic polyurethane) production process, raw materials usually need to be pre-mixed before entering the reactor. This is a key step to ensure the uniformity of the chemical reaction and the performance of the final product. The following is a detailed analysis:

[0003] 1. Raw material diversity: TPU raw materials typically include polyols (polyester / polyether), diisocyanates (such as MDI and TDI), chain extenders (such as butanediol), and possible additives (flame retardants, masterbatches, etc.). These components vary greatly in physical state (liquid, solid) and viscosity, and direct addition of these components can easily lead to uneven concentrations in certain areas.

[0004] 2. Chemical reaction sensitivity: The molar ratio of isocyanate (-NCO group) to polyol (-OH group) must be strictly matched (e.g., NCO / OH = 1.05–1.1). Failure to do so can lead to incomplete reaction, a broad molecular weight distribution, or side reactions (such as bubble formation and gel formation). If the mixture is not uniform, localized excess (initiating crosslinking) or insufficient isocyanate (chain termination) may result in a decrease in the mechanical properties of the TPU (tensile strength, elasticity).

[0005] In order to improve the premixing efficiency, two upper and lower chambers are currently set up inside the premixing tank. The upper chamber is used to premix the raw materials, and the premixed raw materials flow into the lower chamber for temporary storage. When the premixed raw materials are needed, they only need to be pumped from the lower chamber into the reactor. However, the inventors found the following problems during the premixing process:

[0006] Due to the poor fluidity of TPU raw materials, the impact force exerted by the raw materials on the inner wall of the premixing tank during movement is small, so that part of the raw materials will adhere to the inner wall of the premixing tank, and this part of the raw materials will always adhere to the inner wall of the premixing tank, making it difficult to evenly mix the raw materials adhered to the inner wall of the premixing tank. Summary of the Invention

[0007] The purpose of the present invention is to provide a premixing device for the production of TPU plastic pellets, which changes the height of the raw materials by setting a partition, so that the attached raw materials are exposed, and then uses the impact force of the raw materials to flush the attached raw materials down, thereby solving the problem raised in the above-mentioned background technology, that is, the raw materials adhered to the inner wall of the premixing tank are difficult to be evenly mixed.

[0008] To achieve the above-mentioned purpose, a premixing device for the production of TPU plastic pellets includes a premixing tank, a top cover, and a stirring shaft rotatably arranged in the premixing tank, wherein the outer ring of the stirring shaft is provided with a stirring plate; a partition and a blocking member are provided inside the premixing tank, wherein the blocking member is sleeved on the outer ring of the stirring shaft and penetrates the partition;

[0009] The premixing tank further includes a driving mechanism configured to drive the partition or the blocking member to move along the axial direction of the mixing shaft to reduce the height of the raw material on the top of the partition to expose the raw material attached to the inner wall of the premixing tank;

[0010] The side wall of the stirring plate is provided with a flow guide, which guides the raw materials on the top of the partition to the exposed part in a centrifugal force manner, so as to flush the raw materials in the exposed part downward.

[0011] The blocking member is a cylindrical structure sleeved on the outer ring of the stirring shaft; the portion of the partition corresponding to the blocking member is provided with a through opening.

[0012] In the above technical solution, when the partition descends or the partition is separated from the blocking member, the height of the raw materials begins to decrease, exposing the attached raw materials. After being exposed, the rotation of the stirring plate is used to throw the remaining raw materials toward the exposed part, causing the raw materials in the exposed part to be washed down.

[0013] On this basis, the flow guide comprises a side plate fixedly mounted on the side wall of the stirring plate; a flow guide cavity is provided between the side plate and the stirring plate; the end of the flow guide cavity facing the inner wall of the premixing tank is an open structure, and a plurality of guide plates are provided within the opening structure for guiding the raw materials to the exposed part; an inlet is provided at the bottom of the side plate, which is connected to the flow guide cavity. The inlet is provided in a protruding portion at the bottom of the side plate.

[0014] The function of the protrusion is to prevent the stirring plate from being immersed in the raw material, which can increase the speed of the raw material when it is thrown out, thereby improving the efficiency of flushing the raw material from the exposed part.

[0015] On this basis, the driving mechanism includes a cylinder and a driven rod connected to the movable end of the cylinder. There are two specific driving schemes:

[0016] Option 1: The blocking member is fixedly connected to the stirring shaft, and the partition is slidably connected to the premixing tank; the cylinder is arranged on the top cover, and the driven rod slides through the top cover and is fixedly connected to the top of the partition; the cylinder drives the partition to descend, exposing the raw materials attached to the inner wall of the premixing tank.

[0017] Option 2: The blocking member is slidably connected to the stirring shaft, and the partition is fixedly connected to the premixing tank; the cylinder is arranged on the side wall of the premixing tank, and the driven rod slides through the premixing tank and is rotatably connected to the blocking member; the cylinder drives the blocking member to descend, exposing the raw materials attached to the inner wall of the premixing tank.

[0018] Both of the above solutions are driven by air cylinders. No matter whether the partition is driven to descend or the blocking member is driven to descend, the raw materials on the inner wall of the premixing tank can be exposed.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. In the ingredient premixing device for TPU plastic pellet production, the raw materials attached to the inner wall of the premixing tank are exposed by adjusting the height of the partition or reducing the capacity of the raw materials on the top of the partition. Then, the guide piece is used to throw the raw materials to the exposed part, so that the exposed part is impacted by the raw materials, thereby flushing the attached raw materials down and achieving stirring and mixing of the attached raw materials.

[0021] 2. In the ingredient premixing device for the production of TPU plastic pellets, the relative movement between the partition and the blocking member can make the flushed raw materials flow from the side wall of the premixing tank to the center of the premixing tank, realize the contact between the flushed raw materials and the stirring plate, and complete the mixing of the flushed raw materials through the rotation of the stirring plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the partition of the present invention;

[0024] Figure 3 It is a structural schematic diagram of the side panel of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the flow guide of the present invention;

[0026] Figure 5 Schematic diagram of the cross-sectional structure of the side panel of the present invention;

[0027] Figure 6 It is a structural schematic diagram of the guide plate of the present invention;

[0028] Figure 7 The working state of the partition of the present invention is shown as follows Figure 1 ;

[0029] Figure 8 The working state of the partition of the present invention is shown as follows Figure 2 ;

[0030] Figure 9 is a schematic structural diagram of a blocking member of the present invention;

[0031] Figure 10 Schematic diagram of the working state of the blocking member of the present invention.

[0032] The meaning of each number in the figure is:

[0033] 100. Premixing tank; 101. Top cover; 102. Dosing port; 103. Discharge port; 104. Stirring shaft; 105. Stirring plate; 106. Shell; 110. Partition; 111. Through port; 120. Blocking member; 130. Guide member; 131. Side plate; 132. Inlet; 133. Guide chamber; 134. Guide plate; 140. Cylinder; 141. Follower rod; 200. Attachment portion. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] Aiming at the problem that the raw materials adhering to the inner wall of the premixing tank 100 are difficult to be mixed evenly, the present invention provides a premixing device for the production of TPU plastic pellets. Figure 1 As shown, the premixing device includes a premixing tank 100 and a top cover 101 provided on the top of the premixing tank 100. A plurality of dosing ports 102 are provided on the top of the top cover 101. A plurality of raw materials are added into the corresponding dosing ports 102 according to a preset ratio, and then enter the interior of the premixing tank 100 through the dosing ports 102. After the addition, the dosing ports 102 can be blocked. In addition, a stirring shaft 104 is rotatably provided on the top of the premixing tank 100. The top end of the stirring shaft 104 is connected to the motor installed on the top of the top cover 101, and the bottom end extends to the bottom of the premixing tank 100. At the same time, the outer ring of the stirring shaft 104 is also provided with a stirring plate 105 for stirring the raw materials in the premixing tank 100. The bottom of the premixing tank 100 is a conical or arc-shaped structure that facilitates the flow of raw materials to the bottom. A discharge port 103 is provided at the bottom of the arc-shaped structure. By opening the discharge port 103, the premixed raw materials in the premixing tank 100 are transported to the next process (i.e., the reactor).

[0036] The outer portion of the premixing tank 100 is covered with a casing 106, and the premixing tank 100 can be heated by conveying heated oil into the casing 106. Of course, electric heating can also be used.

[0037] A partition 110 and a blocking member 120 are provided inside the premixing tank 100. The outer ring of the partition 110 fits with the inner ring of the premixing tank 100, so that the partition 110 divides the upper half of the premixing tank 100 into a premixing chamber and the lower half into a collecting chamber; correspondingly, stirring plates 105 are provided in both the premixing chamber and the collecting chamber. The blocking member 120 is sleeved on the outer ring of the stirring shaft 104 and is provided through the partition 110. The direction in which the blocking member 120 penetrates the partition 110 is consistent with the axial direction of the stirring shaft 104. With this design, the raw materials will first fall on the top of the partition 110, that is, in the premixing chamber, and then be stirred and mixed in the premixing chamber. After the mixing is completed, the blocking member 120 is controlled to separate from the penetrated portion of the partition 110, and the raw materials premixed on the top of the partition 110 can flow into the collecting chamber through the penetrated portion of the partition 110.

[0038] In the above description, the control of the blocking member 120 from disengaging from the penetrated portion of the partition 110 is achieved through a drive mechanism. Specifically, the drive mechanism is configured to drive the partition 110 or the blocking member 120 to move axially along the agitator shaft 104, thereby lowering the height of the raw material above the partition 110 and exposing the raw material adhered to the inner wall of the premixing tank 100. Specifically, the drive mechanism includes a cylinder 140 and a driven rod 141 connected to the movable end of the cylinder 140.

[0039] In addition, a guide member 130 is provided on the side wall of the stirring plate 105 in the collecting chamber. The guide member 130 guides the raw materials on the top of the partition 110 to the exposed portion by means of centrifugal force, so as to flush the raw materials in the exposed portion downward.

[0040] That is to say, by adjusting the height of the partition 110 or reducing the capacity of the raw material on the top of the partition 110, the raw material attached to the inner wall of the premixing tank 100 is exposed, and then the guide member 130 is used to throw the raw material to the exposed part, so that the exposed part is impacted by the raw material, thereby flushing the attached raw material down, thereby achieving stirring and mixing of the attached raw material.

[0041] like Figure 2 As shown, the blocking member 120 is a cylindrical structure sleeved on the outer ring of the stirring shaft 104; the portion of the partition 110 corresponding to the blocking member 120 is provided with a through opening 111, so that when the blocking member 120 enters the through opening 111, the raw materials on the top of the partition 110 cannot flow downward through the through opening 111.

[0042] Then, if Figure 3 As shown, the guide member 130 includes a side plate 131 fixedly arranged on the side wall of the stirring plate 105; Figure 4As shown, the upper and lower ends of the side plate 131 are bent toward the stirring plate 105, forming a guide cavity 133 between the side plate 131 and the stirring plate 105. Furthermore, the bottom of the side plate 131 protrudes downward to form a protrusion, and an inlet 132 communicating with the guide cavity 133 is provided on the side of the protrusion facing the rotation direction of the stirring shaft 104. The end of the side plate 131 closest to the stirring shaft 104 is a sealed structure, while the end away from the stirring shaft 104 is an open structure. A plurality of guide plates 134 are provided in the opening of the side plate 131 for guiding the raw materials to the exposed portion.

[0043] In the above, the role of the protrusion is to prevent the stirring plate 105 from being immersed in the raw material and to separate the opening of the side plate 131 from the raw material. Because the fluidity of the TPU raw material is poor, if the opening of the side plate 131 is located in the raw material, it will affect the strength of the throw-out.

[0044] like Figure 5 As shown, in some embodiments, the angles of the multiple guide plates 134 within the same side plate 131 vary, specifically decreasing from top to bottom. In this embodiment, when the raw materials within the diversion cavity 133 are ejected under the action of centrifugal force, the guide plates 134 with larger angles will guide the raw materials to the higher part of the exposed area, while the guide plates 134 with smaller angles will guide the raw materials to the lower part of the exposed area.

[0045] like Figure 6 As shown, in other embodiments, the angles between the multiple guide plates 134 in the same side plate 131 are the same (refer to Figure 6 The angles of the guide plates 134 in the side plates 131 are different (refer to Figure 6 In this embodiment, when the raw materials in the guide cavity 133 are thrown out under the action of centrifugal force, for example, Figure 6 The guide plate 134 in the middle A portion guides the raw material to the lower part of the exposed part, corresponding to Figure 6 The guide plate 134 in the middle B portion guides the raw material to the high point of the exposed portion.

[0046] In the above, the driving mechanism can drive the partition 110 or the blocking member 120 to move. The following two embodiments will be used to describe this in detail:

[0047] like Figure 1As shown, in some embodiments, the blocking member 120 is fixedly connected to the stirring shaft 104, and the partition 110 is slidably connected to the premixing tank 100. The cylinder 140 is disposed on the top cover 101. The driven rod 141 slides through the top cover 101 and is fixedly connected to the top of the partition 110. In this embodiment, during the expansion and contraction process, the cylinder 140 drives the partition 110 to rise and fall via the driven rod 141. When the partition 110 descends, the height of the raw material on the top of the partition 110 decreases, exposing the raw material adhering to the inner wall of the premixing tank 100.

[0048] The specific principles of this embodiment are described in detail below:

[0049] like Figure 7 As shown, height H1 represents the height of the raw materials during the mixing process. After the raw materials are mixed on top of partition 110, the drive mechanism controls the downward movement of partition 110, forcing the raw materials to descend to a height of H2. As can be seen, after the raw materials descend from height H1 to height H2, the portion between heights H1 and H2 is no longer obstructed by the raw materials and is exposed within premixing tank 100. In other words, the attachment portion 200 is exposed between heights H1 and H2.

[0050] Then, when inlet 132 is within the raw material and side plate 131 is positioned above it, stirring plate 105 is controlled to rotate. This rotation drives side plate 131, which then rotates to shovel the raw material through inlet 132 into diversion chamber 133. Centrifugal force then forces the raw material within diversion chamber 133 out through the opening of side plate 131 and onto attachment portion 200. As the raw material is being thrown out, it is guided by guide plate 134 to various locations within attachment portion 200. Consequently, the raw material impacts attachment portion 200 using centrifugal force, pushing it downward.

[0051] Then, if Figure 8 As shown, the partition 110 is driven downward until it is below the blocking member 120. At this time, part of the raw material on the top of the partition 110 flows out through the opening 111, forcing the raw material near the side wall of the premixing tank 100 to flow toward the center of the premixing tank 100 ( Figure 8 direction of the solid arrow).

[0052] Finally, the control partition 110 moves up to make the stirring plate 105 contact the raw material, and the raw material washed down is stirred and mixed by the stirring plate 105. After the mixing is completed, the control partition 110 moves down to open the port 111, so that the raw material flows into the bottom of the partition 110.

[0053] like Figure 9As shown, in other embodiments, the blocking member 120 is slidably connected to the stirring shaft 104, and the partition 110 is fixedly connected to the premixing tank 100. The cylinder 140 is disposed on the side wall of the premixing tank 100; after the driven rod 141 slides through the premixing tank 100, it is rotatably connected to the blocking member 120. In this embodiment, the cylinder 140 drives the blocking member 120 downward via the driven rod 141, causing the blocking member 120 to disengage from the through-port 111, thereby opening the through-port 111 and allowing the raw materials on the top of the partition 110 to flow downward through the through-port 111 into the collection chamber. At this time, the height of the raw materials on the top of the partition 110 is lowered, exposing the raw materials attached to the inner wall of the premixing tank 100.

[0054] The specific principles of this embodiment are described in detail below:

[0055] like Figure 10 As shown, height H1 represents the height of the raw materials during the mixing process. After the raw materials are mixed at the top of partition 110, the driving mechanism controls the downward movement of blocking member 120, causing the raw materials at the top of partition 110 to be discharged through opening 111, causing the height of the raw materials at the top of partition 110 to drop to H2. It can be seen that after the raw materials drop from height H1 to height H2, the portion between heights H1 and H2 is no longer obstructed by the raw materials and is exposed within premix tank 100. In other words, the attachment portion 200 is exposed between heights H1 and H2.

[0056] Then, when inlet 132 is within the raw material and side plate 131 is above it, blocking member 120 is controlled to reset, blocking opening 111. Side plate 131 is then rotated by agitator plate 105, shoveling the raw material through inlet 132 into diversion chamber 133. Centrifugal force propels the raw material within diversion chamber 133 through the opening of side plate 131 and out to attachment portion 200. Furthermore, as the raw material is ejected, it is guided by guide plate 134 to various locations within attachment portion 200. Consequently, the raw material impacts attachment portion 200 using centrifugal force, pushing it downward.

[0057] Then, the blocking member 120 is driven downward until it is located below the partition 110. At this time, part of the raw material on the top of the partition 110 flows out through the opening 111, forcing the raw material near the side wall of the premixing tank 100 to flow toward the center of the premixing tank 100 ( Figure 10 direction of the solid arrow).

[0058] Finally, the blocking member 120 is controlled to move upward to make the stirring plate 105 contact the raw materials, and the raw materials washed down are stirred and mixed by the stirring plate 105. After the mixing is completed, the blocking member 120 is controlled to move downward to open the opening 111, so that the raw materials flow into the bottom of the partition 110.

[0059] In summary, the relative movement between the partition 110 and the blocking member 120 can make the flushed raw materials flow from the side wall of the premixing tank 100 to the center of the premixing tank 100, realize the contact between the flushed raw materials and the stirring plate 105, and complete the mixing of the flushed raw materials through the rotation of the stirring plate 105.

[0060] It should be understood that the raw materials in the collection chamber are in a uniformly mixed state, so if the raw materials adhere to the inner wall of the collection chamber, no intervention is required. In addition, when the adhered raw materials are flushed out, new raw materials will also adhere to the interior of the premixing tank 100, but the new raw materials are already uniformly mixed, so the adhesion of new raw materials will not cause any impact.

[0061] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A premixing device for producing TPU plastic pellets, comprising a premixing tank (100), a top cover (101), and a stirring shaft (104) rotatably arranged in the premixing tank (100), wherein the outer ring of the stirring shaft (104) is provided with a stirring plate (105); characterized in that: A partition (110) and a blocking member (120) are provided inside the premixing tank (100), wherein the blocking member (120) is sleeved on the outer ring of the stirring shaft (104) and penetrates the partition (110); The invention also includes a driving mechanism configured to drive the partition (110) or the blocking member (120) to move along the axial direction of the stirring shaft (104) to reduce the height of the raw material on the top of the partition (110) so as to expose the raw material attached to the inner wall of the premixing tank (100); A flow guide (130) is provided on the side wall of the stirring plate (105), and the flow guide (130) guides the raw materials on the top of the partition (110) to the exposed portion by means of centrifugal force, so as to flush the raw materials in the exposed portion downward; The flow guide (130) comprises a side plate (131) fixedly mounted on a side wall of the stirring plate (105); a flow guide cavity (133) is provided between the side plate (131) and the stirring plate (105); one end of the flow guide cavity (133) facing the inner wall of the premixing tank (100) is an open structure, and a plurality of guide plates (134) for guiding the raw materials to the exposed portion are provided in the open structure; The bottom of the side plate (131) is provided with an inlet (132) communicating with the diversion cavity (133); The inlet (132) is arranged in a protruding portion at the bottom of the side plate (131).

2. The premixing device for producing TPU plastic pellets according to claim 1, characterized in that: The blocking member (120) is a cylindrical structure sleeved on the outer ring of the stirring shaft (104); A through opening (111) is provided at a position of the partition (110) corresponding to the blocking member (120).

3. The premixing device for producing TPU plastic pellets according to claim 1, characterized in that: The angles between the multiple guide plates (134) in the same side plate (131) are different.

4. The premixing device for producing TPU plastic pellets according to claim 1, characterized in that: The angles between the multiple guide plates (134) in the same side plate (131) are the same; the angles of the guide plates (134) in the multiple side plates (131) are different.

5. The premixing device for producing TPU plastic pellets according to claim 1, characterized in that: The driving mechanism comprises a cylinder (140) and a driven rod (141) connected to the movable end of the cylinder (140).

6. The premixing device for producing TPU plastic pellets according to claim 5, characterized in that: The blocking member (120) is fixedly connected to the stirring shaft (104), and the partition (110) is slidably connected to the premixing tank (100); The cylinder (140) is arranged on the top cover (101), and the driven rod (141) slides through the top cover (101) and is fixedly connected to the top of the partition (110); the cylinder (140) drives the partition (110) to descend, so that the raw materials attached to the inner wall of the premixing tank (100) are exposed.

7. The premixing device for producing TPU plastic pellets according to claim 5, characterized in that: The blocking member (120) is slidably connected to the stirring shaft (104), and the partition (110) is fixedly connected to the premixing tank (100); The cylinder (140) is arranged on the side wall of the premixing tank (100), and the driven rod (141) slides through the premixing tank (100) and is rotatably connected to the blocking member (120); the cylinder (140) drives the blocking member (120) to descend, thereby exposing the raw materials attached to the inner wall of the premixing tank (100).

8. The premixing device for producing TPU plastic pellets according to claim 1, characterized in that: Stirring plates (105) are provided above and below the partition (110).

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