Split-cavity adjusting type fluidized bed for plastic powder dip-coating

Abstract

The utility model relates to the technical field of plastic powder dip-coating, and discloses a split-cavity adjustable fluidized bed for plastic powder dip-coating, which comprises a bed body with a hollow structure; the interlayer is formed by double-layer overlapped canvas, the interlayer is horizontally arranged at the lower part in the bed body so as to divide the bed body into an air chamber and a powder chamber, and the air chamber is positioned at the lower part of the powder chamber; the partition plates are vertically arranged in the air chamber so as to divide the air chamber into a plurality of air cavities; the output end of the gas path system is communicated with the bed body; the gas path system comprises a gas source connector, a main valve, a filter, a gas conveying pipe and a flow adjusting valve. The canvas is used as the interlayer, so that smooth circulation of airflow from the air chamber to the powder chamber is ensured; the cavity-divided air chamber is arranged, so that the molding powder boiling effect of each area in the fluidized bed is controlled in a partitioned manner, and the optimal coating effect is achieved; the filter equipment is added, so that air entering the fluidized bed does not contain impurities, air entering the powder chamber does not contain moisture, and the problem that molding powder is polluted by airflow is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic powder dip coating, and particularly relates to a cavity-dividing adjustable fluidized bed for plastic powder dip coating. Background Art

[0002] Plastic powder dip coating is a process in which compressed air is used to suspend plastic powder in a fluidized bed, presenting a tumbling "boiling" state. The preheated workpiece is immersed in the "boiling" plastic powder. After the plastic powder adheres to the surface of the workpiece, it is heated and melted by the heat of the workpiece and firmly adheres to the surface of the workpiece, serving functions such as anti-corrosion and decoration. The basic principle of fluidized bed technology is to evenly stack solid plastic powder particles in a container with a porous partition, forming a particle bed. Compressed air is introduced into the part below the container partition. The air flow passes through the partition from bottom to top and enters the particle bed layer. At low flow rates, the particles remain stationary. As the flow rate increases, the particles start to move and the bed layer expands. Eventually, at a sufficiently high flow rate, the particles will move violently in the air flow, forming a fluidized state.

[0003] The fluidized bed applied to the plastic powder dip coating of valves and pipe fittings is a relatively common application example of fluidized bed technology. This fluidized bed consists of a bed body and a gas pipeline. Among them, the bed body includes three structures: an air chamber, a powder chamber, and a partition layer. The gas pipeline is connected to the air chamber to provide compressed air for the fluidized bed; the powder chamber is used to hold the plastic powder for dip coating; the partition layer is a partition between the air chamber and the powder chamber and is also the channel for compressed air to enter the powder chamber from the air chamber. Usually, the partition layer uses a porous air-permeable plate. The simple structure of the fluidized bed in the prior art is as Figure 1-2 shown. When the fluidized bed works, the interface of the gas pipeline is connected to the compressed air pipeline. Compressed air enters the air chamber through the gas pipeline. After the air chamber is filled, the compressed air passes through the air-permeable plate and enters the powder chamber. The plastic powder in the powder chamber is suspended under the action of air flow and tumbles along the air flow trajectory with the continuous entry of air. From the outside, the plastic powder in the powder chamber presents a "boiling" state. By controlling the flow rate of compressed air, the "boiling" degree of the plastic powder can be adjusted. When the appropriate state is reached, plastic powder dip coating can be carried out.

[0004] Traditional fluidized beds can be applied to the powder dipping of most products. However, in practice, it is found that they still have deficiencies. Especially when dipping products with larger volumes, that is, when the required fluidized bed size is large, the traditional fluidized bed needs to be optimized in two aspects: First, the safety of the partition layer is insufficient. The partition layer of the traditional fluidized bed uses a porous breathable plate, and the commonly used materials are plastic or ceramic. This kind of plate has good air permeability and can well conduct the air in the air chamber to the powder chamber. However, plastic or ceramic materials are relatively brittle in themselves. When dipping larger products, if the product falls, the partition plate is prone to cracking. Second, the "boiling" effect in the powder chamber is not good, mainly manifested as uneven "boiling" in the powder chamber: the "boiling" effect is good in some positions, with obvious bubbles and good fluidity of the plastic powder with the air flow; the "boiling" effect is poor in some positions, with small bubbles and poor fluidity of the plastic powder with the air flow. This phenomenon of poor "boiling" effect will affect the dipping quality of the product to a certain extent, especially for large products. Large products will occupy a large space in the fluidized bed. When encountering areas with poor "boiling" effect, the air flow in this range is poor, which is not conducive to the flow of the plastic powder and the full contact with the workpiece. Eventually, the coating thickness on the surface of the workpiece in this range will be uneven.

[0005] The main reason for the above-mentioned phenomenon of poor "boiling" effect is the unreasonable structure of the fluidized bed air chamber. The air chamber of the traditional fluidized bed is an integral structure, and the air pipeline is connected to the middle position. After the compressed air enters the air chamber, it disperses from the middle to the surrounding. Naturally, there is a trend of large air flow in the middle and small air flow around. Due to the structure of the air chamber, the air flow at different positions cannot be adjusted. When the size of the fluidized bed is small, the air flow difference between the middle and the surrounding is not large. The boiling effects at various positions in the corresponding powder chamber are basically the same. However, when the overall size of the fluidized bed is large, the air flow near the gas source position, that is, the middle position of the fluidized bed, is large, and the boiling effect in the middle position of the corresponding powder chamber is good; the air flow at the position far from the gas source, that is, the surrounding position of the fluidized bed, is small, and the boiling effect at the outer side position of the corresponding powder chamber is not good.

[0006] Therefore, there is an urgent need for a cavity-separated adjustable fluidized bed for plastic powder dipping to solve the problems that the partition layer of the traditional fluidized bed for plastic powder dipping is prone to cracking, and the fluidized bed is not conducive to the flow of the plastic powder and the full contact with the workpiece, resulting in uneven coating thickness on the surface of the workpiece. Utility Model Content

[0007] In view of this, the present utility model proposes a cavity-separated adjustable fluidized bed for plastic powder dipping, aiming to solve the problems that the partition layer of the traditional fluidized bed for plastic powder dipping is prone to cracking, and the fluidized bed is not conducive to the flow of the plastic powder and the full contact with the workpiece, resulting in uneven coating thickness on the surface of the workpiece.

[0008] The present utility model provides a cavity-separated adjustable fluidized bed for plastic powder dipping, including:

[0009] The bed body is set as a hollow structure;

[0010] The partition layer is composed of double-layer superimposed canvas, and the partition layer is horizontally arranged at the lower part inside the bed body to divide the bed body into an air chamber and a powder chamber, and the air chamber is located below the powder chamber;

[0011] A plurality of partition plates are provided, and the partition plates are vertically arranged in the air chamber to divide the air chamber into a plurality of air cavities;

[0012] An air path system, the output end of the air path system is communicated with the bed body; wherein, the air path system includes an air source connector, a main valve, a filter, an air delivery pipe and a flow regulating valve;

[0013] One end of the air source connector is connected to an external compressed air pipeline, the other end of the air source connector is communicated with the main valve, the air source connector is used to provide air source for the fluidized bed, the end of the main valve away from the air source connector is communicated with the filter, an air delivery pipe is arranged at the end of the filter away from the main valve, the air delivery pipe is communicated with the air chamber, and the flow regulating valve is arranged on the air delivery pipe.

[0014] Further, the air chamber accounts for one-fifth of the inner cavity of the bed body, and the powder chamber accounts for four-fifths of the inner cavity of the bed body, so that the space ratio of the air chamber to the powder chamber is 1:4.

[0015] Further, the number of the air cavities is at least 3.

[0016] Further, the cavity-adjustable fluidized bed for plastic powder dipping further includes:

[0017] An air delivery port is opened at the connection part of the air delivery pipe and the bed body;

[0018] One or more air delivery ports are arranged at the end of each air delivery pipe away from the filter.

[0019] Further, when the length of the air cavity is less than 500 mm, the number of the air delivery ports is one, and for every 500 mm increase in the length of the air cavity, the number of the air delivery ports increases by one.

[0020] Further, when the air delivery port is set to one, the air delivery port is arranged at the central position of the air cavity;

[0021] When the air delivery ports are set to multiple, the distance between every two air delivery ports is not less than 300 mm.

[0022] Further, the air delivery ports are arranged in a straight line.

[0023] Further, a plurality of flow regulating valves are provided, and each flow regulating valve is disposed on each gas pipeline.

[0024] Compared with the prior art, the beneficial effects of the present utility model are as follows: using canvas to replace the porous breathable plate as the interlayer material has good air permeability, which is beneficial to the passage of air through the fabric interior. Using canvas as the interlayer material can ensure smooth air flow from the air chamber to the powder chamber. The canvas itself has certain water absorption performance, which can secondarily absorb the moisture in the air, further ensuring that the air entering the powder chamber is moisture-free. The canvas has good toughness. Using canvas as the interlayer material, even if the painted parts accidentally fall, the canvas will not be easily broken, which can effectively improve the safety and fault tolerance during the use of the fluidized bed; changing the overall air chamber to a divided chamber air chamber realizes the zoning control of the plastic powder boiling effect in each area of the fluidized bed. Especially when painting large products, different requirements for the boiling effect of plastic powder in different areas are required to achieve the best painting effect; a filtering device is added to the gas circuit system to ensure that the air entering the interior of the fluidized bed does not contain impurities such as water and oil, effectively avoiding the problem of air flow polluting the plastic powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present utility model. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0026] Figure 1 is a schematic structural diagram of a fluidized bed in the prior art;

[0027] Figure 2 is a cross-sectional view of a fluidized bed in the prior art;

[0028] Figure 3 is a schematic structural diagram of a divided chamber adjustable fluidized bed for plastic powder dip coating with three gas chambers provided by an embodiment of the present utility model;

[0029] Figure 4 is a cross-sectional view of a divided chamber adjustable fluidized bed for plastic powder dip coating with three gas chambers provided by an embodiment of the present utility model;

[0030] Figure 5 is a schematic structural diagram of the lower part of a divided chamber adjustable fluidized bed for plastic powder dip coating with three gas chambers provided by an embodiment of the present utility model;

[0031] Figure 6 is a cross-sectional view of a divided chamber adjustable fluidized bed for plastic powder dip coating with five gas chambers provided by an embodiment of the present utility model;

[0032] Figure 7The structural schematic diagram of the lower part of the cavity-separating adjustable fluidized bed for plastic powder dip coating with five air cavities provided by the embodiment of the present utility model.

[0033] In the figure: 100, bed body; 200, partition layer; 300, air chamber; 400, powder chamber; 500, partition board; 600, air cavity; 700, air path system; 710, air source connector; 720, main valve; 730, filter; 740, gas pipeline; 750, flow regulating valve; 800, gas delivery port. Specific embodiments

[0034] The following combines the drawings and embodiments to further describe in detail the specific embodiments of the present utility model. The following embodiments are used to illustrate the present utility model, but are not used to limit the scope of the present utility model.

[0035] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0036] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0037] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0038] Refer to Figure 3-7As shown in the figure, this embodiment provides a cavity-adjustable fluidized bed for powder dipping coating, which includes a bed body 100, configured as a hollow structure; a partition layer 200, composed of double-layered superimposed canvas, horizontally arranged at the lower part inside the bed body 100 to divide the bed body 100 into an air chamber 300 and a powder chamber 400, with the air chamber 300 located at the lower part of the powder chamber 400; a plurality of partition plates 500, vertically arranged in the air chamber 300 to divide the air chamber 300 into several air cavities 600; an air path system 700, the output end of the air path system 700 is communicated with the bed body 100; wherein, the air path system 700 includes an air source connector 710, a main valve 720, a filter 730, an air delivery pipe 740 and a flow regulating valve 750; one end of the air source connector 710 is connected to an external compressed air pipeline, the other end of the air source connector 710 is communicated with the main valve 720, the air source connector 710 is used to provide air source for the fluidized bed, the end of the main valve 720 away from the air source connector 710 is connected to the filter 730, the filter 730 is provided with an air delivery pipe 740 at the end away from the main valve 720, the air delivery pipe 740 is communicated with the air chamber 300, and the flow regulating valve 750 is arranged on the air delivery pipe 740.

[0039] It can be understood that using canvas instead of a porous breathable plate as the partition layer 200 has good air permeability, which is beneficial to the passage of air through the interior of the fabric. Using canvas as the material of the partition layer 200 can ensure smooth air flow from the air chamber 300 to the powder chamber 400. The canvas itself has a certain water absorption capacity, which can secondarily absorb the moisture in the air, further ensuring that the air entering the powder chamber 400 is moisture-free. The canvas has good toughness. Using canvas as the material of the partition layer 200, even if a painted part accidentally drops, the canvas will not be easily broken, which can effectively improve the safety and fault tolerance during the use of the fluidized bed; changing the overall air chamber 300 to a cavity air chamber 300 realizes the zonal control of the boiling effect of the powder in each area inside the fluidized bed. Especially when painting large products, different requirements for the boiling effect of the powder in different areas are required to achieve the best painting effect; a filtering device is added to the air path system 700 to ensure that the air entering the interior of the fluidized bed does not contain impurities such as water and oil, effectively avoiding the problem of air flow polluting the powder.

[0040] In some embodiments of the present application, the air chamber 300 accounts for one-fifth of the inner cavity of the bed body 100, and the powder chamber 400 accounts for four-fifths of the inner cavity of the bed body 100, so that the space ratio of the air chamber 300 to the powder chamber 400 is one to four.

[0041] In some embodiments of the present application, the air cavity 600 is set to at least 3.

[0042] It can be understood that by setting the spatial ratio of the gas chamber 300 to the powder chamber 400 to 1:4 and setting the number of gas cavities 600 to at least 3, the gas distribution of the fluidized bed can be effectively optimized, ensuring that the gas enters the powder chamber 400 evenly, thereby improving the fluidization effect of the powder. This not only improves the coating uniformity of the powder but also enables flexible adjustment of the working state of the fluidized bed according to different operating requirements, enhancing the adaptability and controllability of the equipment.

[0043] In some embodiments of the present application, the cavity-adjustable fluidized bed for plastic powder dip coating further includes a gas delivery port 800, which is opened at the connection of the gas delivery pipe 740 and the bed body 100; one or more gas delivery ports 800 are provided at one end of each gas delivery pipe 740 away from the filter 730.

[0044] In some embodiments of the present application, when the length of the gas cavity 600 is less than 500 mm, the number of gas delivery ports 800 is one, and for every 500 mm increase in the length of the gas cavity 600, the number of gas delivery ports 800 increases by one.

[0045] In some embodiments of the present application, when the gas delivery port 800 is set to one, the gas delivery port 800 is set at the central position of the gas cavity 600;

[0046] When the gas delivery ports 800 are set to multiple, the distance between every two gas delivery ports 800 is not less than 300 mm.

[0047] In some embodiments of the present application, the gas delivery ports 800 are arranged in a straight line.

[0048] It can be understood that by setting the gas delivery ports 800 and adjusting their number and position according to the length of the gas cavity 600, more precise control of gas distribution can be achieved. When the length of the gas cavity 600 is relatively small, only one gas delivery port 800 is needed to meet the requirements. As the length of the gas cavity 600 increases, gradually increasing the number of gas delivery ports 800 can ensure the uniform supply of gas throughout the gas cavity 600. The reasonable distance between the gas delivery ports 800 and the straight-line arrangement further avoid the fluidization instability caused by uneven air flow, enhancing the consistency of the coating and the repeatability of the process, and improving the working efficiency of the equipment and the product quality. Distributing two or more gas delivery ports 800 in a single gas cavity 600 can perform zonal control of the gas flow in different regions of the gas cavity 600 to achieve the zonal adjustment function of the boiling effect in the powder chamber 400.

[0049] In some embodiments of the present application, several flow regulating valves 750 are provided, and each flow regulating valve 750 is provided on each gas delivery pipe 740.

[0050] It can be understood that zonal control of the gas flow in different regions of the gas cavity 600 can be performed to achieve the zonal adjustment function of the boiling effect in the powder chamber 400.

[0051] Working principle of the utility model: When the fluidized bed works, an appropriate amount of plastic powder is loaded into the powder chamber 400. The height of the plastic powder should not exceed 80% of the total height of the inner cavity of the fluidized bed body 100 to prevent plastic powder splashing caused by boiling. The flow regulating valve 750 is opened in sequence, and the valve is half-opened in the initial state; the main valve 720 is opened, so that after the external air source is dried and filtered by the filter 730, it enters multiple air cavities 600 simultaneously; after the compressed air fills the air cavity 600, it will pass through the canvas partition layer 200 and enter the upper powder chamber 400; the plastic powder in the powder chamber 400 is suspended under the action of air flow, and with the continuous inflow of air, the suspended plastic powder will continuously roll along the air flow path, so that the plastic powder presents a "boiling" state. At this time, observe the boiling situation of the plastic powder in the fluidized bed from the outside. By adjusting the opening degree of the flow regulating valve 750 connected to different air cavities 600, the boiling state of the plastic powder in this area is adjusted. Increasing the valve opening degree can intensify the boiling effect, and decreasing the valve opening degree can weaken the boiling effect. When the boiling effect of the plastic powder in the fluidized bed reaches the expected state, the adjustment of the fluidized bed is completed, and the plastic powder dipping process can be continued.

[0052] Those of ordinary skill in the art can understand that the above description is only a preferred embodiment of the utility model and is not used to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included within the protection scope of the utility model.

Claims

1. A cavity-adjustable fluidized bed for powder dipping, characterized in that, Comprising: A bed body, which is set as a hollow structure; A partition layer, which is composed of double-layered superimposed canvas. The partition layer is horizontally arranged at the lower part inside the bed body to divide the bed body into an air chamber and a powder chamber. The air chamber is located below the powder chamber; A plurality of partition plates, which are vertically arranged in the air chamber to divide the air chamber into a plurality of air cavities; An air path system, the output end of which is communicated with the bed body; wherein, the air path system includes an air source connector, a main valve, a filter, an air pipe and a flow regulating valve; One end of the air source connector is connected to an external compressed air pipeline, and the other end of the air source connector is communicated with the main valve. The air source connector is used to provide air source for the fluidized bed. One end of the main valve away from the air source connector is communicated with the filter. An air pipe is arranged at one end of the filter away from the main valve. The air pipe is communicated with the air chamber. The flow regulating valve is arranged on the air pipe.

2. The cavity-dividing adjustable fluidized bed for plastic powder dipping according to claim 1, wherein The air chamber occupies one-fifth of the inner cavity of the bed body, and the powder chamber occupies four-fifths of the inner cavity of the bed body, so that the space ratio of the air chamber to the powder chamber is 1:

4.

3. The cavity-dividing adjustable fluidized bed for plastic powder dipping according to claim 2, wherein The air cavities are at least arranged in 3.

4. The cavity-adjustable fluidized bed for powder dipping according to claim 3, wherein The cavity-dividing adjustable fluidized bed for plastic powder dipping further includes: An air delivery port, which is opened at the connection part of the air pipe and the bed body; One or more air delivery ports are arranged at one end of each air pipe away from the filter.

5. The cavity-dividing adjustable fluidized bed for plastic powder dipping according to claim 4, wherein When the length of the air cavity is less than 500 mm, the number of the air delivery ports is one. For every 500 mm increase in the length of the air cavity, the number of the air delivery ports increases by one.

6. The cavity-dividing adjustable fluidized bed for plastic powder dipping according to claim 5, wherein When the air delivery port is arranged as one, the air delivery port is arranged at the central position of the air cavity; When the air delivery ports are arranged as multiple, the distance between every two air delivery ports is not less than 300 mm.

7. The cavity-dividing adjustable fluidized bed for plastic powder dipping according to claim 6, wherein The air delivery ports are arranged in a straight line.

8. The cavity-dividing adjustable fluidized bed for plastic powder dipping according to claim 7, wherein A plurality of flow regulating valves are arranged, and each flow regulating valve is arranged on each air pipe.

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