A drying apparatus for producing paraformaldehyde

Abstract

The utility model relates to polyformaldehyde production equipment technical field, and disclose a kind of drying equipment for producing polyformaldehyde, including drying cabinet, and the right side of drying cabinet is sequentially communicated with cooling box and purification tank;The inside rotation of drying cabinet is equipped with stirring shaft, and multiple groups of drying plate are uniformly distributed on stirring shaft, and the inside of each group of drying plate is embedded heating pipe;The left side of drying cabinet top is equipped with blower, and the right side of drying cabinet top is equipped with gas-collecting hood, and the right side of gas-collecting hood is connected with cooling box, and the bottom of cooling box is connected with purification tank;The left side bottom of drying cabinet is equipped with drive assembly, and drive assembly is used to control the rotation of stirring shaft.In the utility model, semicircular arc drying cabinet bottom and radial drying plate are accurately matched, cooperate the stirring system of frequency conversion drive, realize raw material dead corner tumbling;S shape distribution heating pipe makes drying plate temperature uniform, superimposed hot air circulation accelerates moisture evaporation, significantly improves drying efficiency and finished product quality stability.

Description

Technical Field

[0001] This utility model relates to the technical field of paraformaldehyde production equipment, and in particular to a drying device for producing paraformaldehyde. Background Technology

[0002] Paraformaldehyde, as an important organic chemical raw material, is widely used in resin synthesis, pharmaceutical intermediates, and pesticide production. Its production process places extremely stringent requirements on the drying stage. Not only must the product's moisture content meet standards, but localized overheating leading to product deterioration must also be avoided, while simultaneously meeting environmental regulations regarding exhaust emissions. Currently, the drying equipment used for paraformaldehyde in the industry mostly employs traditional box-type or drum-type dryers. However, these devices have gradually revealed numerous shortcomings in actual operation.

[0003] In terms of drying efficiency and uniformity, traditional equipment often uses a simple paddle-type stirring structure, which cannot achieve all-round mixing of paraformaldehyde raw materials and is prone to the problem of raw materials accumulating at the bottom of the equipment. Furthermore, it does not have a deep purification structure designed for the trace amounts of formaldehyde vapor and dust particles contained in the paraformaldehyde drying exhaust gas. Directly emitted exhaust gas is prone to causing air pollution and does not meet increasingly stringent environmental protection standards.

[0004] Therefore, those skilled in the art urgently need to develop a drying device for producing paraformaldehyde. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a drying device for producing paraformaldehyde.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a drying device for producing paraformaldehyde, comprising a drying chamber, wherein a feeding hopper is provided on the top of the drying chamber, and a cooling chamber and a purification chamber are sequentially connected to the right side of the drying chamber; The drying chamber is equipped with a rotating stirring shaft inside. The axial direction of the stirring shaft is consistent with the length direction of the drying chamber. Multiple sets of drying plates are evenly distributed on the stirring shaft. Each set of drying plates is equipped with a heating tube. A cavity structure is opened at the center of both ends of the stirring shaft. The two ends of each heating tube are connected to the cavity structures on both sides respectively. The stirring shaft is rotated and sealed on the left and right sides through a first rotary joint and a second rotary joint, respectively. Both the first rotary joint and the second rotary joint are hollow structures and are connected to the cavity structures on the corresponding sides. The first rotary joint is provided with a heat-conducting medium addition pipe, and the second rotary joint is provided with a heat-conducting medium discharge pipe. A blower is located on the upper left side of the drying chamber, and a gas collection hood is located on the upper right side of the drying chamber. The right side of the gas collection hood is connected to the cooling chamber via a first connecting pipe, and the bottom of the cooling chamber is connected to the purification chamber via a second connecting pipe. A drive assembly is located on the bottom left side of the drying chamber, and the drive assembly is used to control the rotation of the stirring shaft.

[0007] Preferably, the cooling box has a drain end and a water inlet end on its side, and a vertically arranged cooling coil is fixedly installed inside the cooling box. The upper and lower ends of the cooling coil are respectively connected to a first connecting pipe and a second connecting pipe, and an air pump is fixedly installed on the second connecting pipe.

[0008] Preferably, the bottom cross-section of the drying chamber is a semi-circular arc structure, adapted to the rotation trajectory of the drying plate driven by the stirring shaft, and the heating tubes are distributed in an S-shape inside the drying plate.

[0009] Preferably, the drive assembly includes a drive motor connected to the bottom of the drying chamber, the output end of the drive motor is fixedly fitted with a drive pulley, and the end of the stirring shaft near the drive motor is fixedly fitted with a driven pulley, and the drive pulley and the driven pulley are connected by belt drive.

[0010] Preferably, the bottom of the purification box is fixedly equipped with a horizontally arranged exhaust main pipe, the input end of the exhaust main pipe is connected to the second connecting pipe, and multiple exhaust branch pipes are equidistantly distributed above the exhaust main pipe, each exhaust branch pipe being connected to the interior of the exhaust main pipe.

[0011] Compared with the prior art, the beneficial effects of this utility model are: In this invention, the semi-circular bottom of the drying chamber is precisely matched with the radial drying plate, and the variable frequency driven stirring system enables the raw materials to be stirred without dead angles; the S-shaped distributed heating tubes ensure uniform temperature of the drying plate, and the hot air circulation accelerates the evaporation of moisture, effectively solving the problems of raw material accumulation and uneven drying, and significantly improving drying efficiency and product quality stability. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a side view of the drying oven described in this utility model. Figure 3 This is a cross-sectional view of the connection structure of the drying plate described in this utility model; Figure 4 This is a front sectional view of the cooling box described in this utility model; Figure 5 This is a front sectional view of the purification box described in this utility model.

[0013] In the diagram: 1-Drying box; 2-Feeding hopper; 3-Cooling box; 31-Drainage end; 32-Water inlet end; 4-Purification box; 5-Stirring shaft; 51-Cavity structure; 6-Drying plate; 7-First rotary joint; 8-Second rotary joint; 9-Heating tube; 10-Drive motor; 11-Belt; 12-Blower; 13-Gas collection hood; 14-First connecting pipe; 15-Cooling coil; 16-Second connecting pipe; 17-Air pump; 18-Exhaust main pipe; 19-Exhaust branch pipe. Detailed Implementation

[0014] The present invention will now be clearly described with reference to the accompanying drawings and specific embodiments. This description is merely for explaining the present invention and is not intended to limit it. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art based on the embodiments of the present invention without inventive effort to obtain all other embodiments should be included within the protection scope of the present invention.

[0015] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0016] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0017] Please see Figures 1-5 This utility model provides an embodiment: a drying device for producing paraformaldehyde, the core components of which include a drying box 1, a cooling box 3, a purification box 4 and a stirring shaft 5, and the units work together to achieve efficient drying of paraformaldehyde and environmentally friendly treatment of exhaust gas.

[0018] Specifically, it includes a drying chamber 1, with a feeding hopper 2 at the top and a controllable valve at the bottom of the feeding hopper 2, which can adjust the feeding rate according to the drying progress to avoid insufficient drying caused by too much raw material being added at once.

[0019] The drying chamber 1 is equipped with a rotating stirring shaft 5. The axial direction of the stirring shaft 5 is consistent with the length direction of the drying chamber 1, ensuring that the stirring range covers the entire internal space of the drying chamber. Multiple sets of drying plates 6 are evenly distributed on the stirring shaft 5. Each set of drying plates 6 is arranged radially and symmetrically, with an angle of 60° between adjacent sets of drying plates 6. Heating tubes 9 are embedded inside each set of drying plates 6. The heating tubes 9 are densely distributed in an S-shape inside the drying plate 6. This distribution method can increase the contact area between the heating tubes and the drying plate, so that the surface temperature of the drying plate 6 is uniform and stable.

[0020] A cavity structure 51 is provided at the center of both ends of the stirring shaft 5. The inner diameter of the cavity structure 51 matches the diameter of the heating tube 9. Both ends of each heating tube 9 are sealed and connected to the cavity structures 51 on both sides to form a complete heat transfer medium circulation channel. To prevent leakage of the heat transfer medium (the heat transfer medium can be hot water or heat transfer oil), the connection between the heating tube 9 and the cavity structure 51 is sealed with high-temperature sealant and reinforced with metal fastening sleeves.

[0021] A blower 12 is provided on the upper left side of the drying chamber 1. The air outlet of the blower 12 extends into the drying chamber 1 and faces the upper part of the stirring area. The blower 12 can blow dry hot air into the chamber to accelerate the evaporation of moisture on the surface of the raw materials. A gas collection hood 13 is provided on the right side of the drying chamber 1. The gas collection hood 13 has a trumpet-shaped structure, with its large opening facing the inside of the drying chamber. It can efficiently collect the humid waste gas generated during the drying process. The small opening of the gas collection hood 13 is connected to the cooling chamber 3 through the first connecting pipe 14.

[0022] The inner wall of the drying oven 1 is also covered with an insulation layer made of aluminum silicate fiber, which can effectively reduce heat loss inside the oven and reduce energy consumption. At the same time, the drying oven 1 is equipped with a temperature sensor to monitor the drying temperature inside the oven in real time.

[0023] The stirring shaft 5 is rotaryly sealed on both sides via a first rotary joint 7 and a second rotary joint 8 (in actual use, the first rotary joint 7 and the second rotary joint 8 are fixed). Both the first rotary joint 7 and the second rotary joint 8 are high-temperature resistant and wear-resistant mechanically sealed rotary joints. Both are hollow structures and are sealed and connected to the corresponding cavity structure 51 to ensure stable circulation of the heat transfer medium during rotation. The first rotary joint 7 is equipped with a heat transfer medium addition pipe, and the second rotary joint 8 is equipped with a heat transfer medium discharge pipe. A temperature monitoring instrument is installed on the discharge pipe to monitor the temperature of the discharged medium in real time.

[0024] A drive assembly is provided on the bottom left side of the drying chamber 1. The drive assembly is used to control the rotation of the stirring shaft 5. The drive assembly includes a drive motor 10 connected to the bottom of the drying chamber 1. The output end of the drive motor 10 is fixedly fitted with a drive pulley, and the end of the stirring shaft 5 near the drive motor 10 is fixedly fitted with a driven pulley. The drive pulley and the driven pulley are connected by a belt 11.

[0025] Furthermore, the right side of the gas collection hood 13 is connected to the cooling box 3 via the first connecting pipe 14. The cooling box 3 is provided with a drain end 31 and a water inlet end 32 on its side. The water flow method of bottom inlet and top outlet can ensure that the interior of the cooling box 3 is always filled with cooling water, thereby improving the cooling effect. The interior of the cooling box 3 is fixedly equipped with a vertically arranged cooling coil 15. The upper and lower ends of the cooling coil 15 are connected to the first connecting pipe 14 and the second connecting pipe 16, respectively. The second connecting pipe 16 is fixedly equipped with an air pump 17. The air pump 17 is a corrosion-resistant centrifugal air pump, which can provide power for the flow of exhaust gas.

[0026] Furthermore, the bottom of the cooling box 3 is connected to the purification box 4 via the second connecting pipe 16; the bottom of the purification box 4 is fixedly equipped with a horizontally arranged exhaust main pipe 18, the input end of the exhaust main pipe 18 is connected to the second connecting pipe 16, and multiple exhaust branch pipes 19 are evenly distributed above the exhaust main pipe 18. Each exhaust branch pipe 19 is connected to the inside of the exhaust main pipe 18. Water can be added to the inside of the purification box 4 to dissolve and adsorb formaldehyde; or activated carbon can be added for adsorption.

[0027] Furthermore, the bottom cross-section of the drying chamber 1 is a semi-circular arc structure, which is adapted to the rotation trajectory of the drying plate 6 driven by the stirring shaft 5. The bottom cross-section is designed as a semi-circular arc structure, which is precisely adapted to the rotation trajectory of the drying plate 6 driven by the stirring shaft 5. This can effectively prevent the paraformaldehyde raw material from accumulating at the bottom of the chamber and ensure that the raw material is in full contact with the drying plate 6.

[0028] Working principle of this utility model: 1. Heat transfer medium (such as heat transfer oil) is injected into the cavity structure 51 of the stirring shaft through the heat transfer medium addition pipe. The heat transfer medium flows through the S-shaped heating pipes 9 in each drying plate 6 to form a closed loop circulation. At the same time, cooling water is injected through the water inlet 31 of the cooling box 3 to ensure that the cooling box is full of cooling water, thus completing the preheating and preparation before the equipment starts.

[0029] 2. Open the valve at the bottom of the feeding hopper 2, and the paraformaldehyde raw material slowly enters the drying chamber 1; start the drive motor 10, which drives the stirring shaft 5 to rotate through the transmission action of the driving pulley, belt 11, and driven pulley. The stirring shaft 5 drives the radial drying plates 6 to rotate synchronously, and the raw material is stirred in all directions. At this time, the heating tube 9 raises the temperature of the drying plates 6 through heat conduction, and heats and dries the paraformaldehyde raw material in contact with it; at the same time, start the blower 12 to blow dry hot air into the drying chamber, which accelerates the evaporation of moisture on the surface of the raw material to form humid waste gas.

[0030] 3. Start the air pump 17. Under negative pressure, the humid waste gas in the drying box is collected by the gas collection hood 13 and enters the cooling coil 15 in the cooling box 3 through the first connecting pipe 14. The cooling water flows around the cooling coil 15 in the cooling box 3 and reduces the temperature of the waste gas through heat exchange. The cooled waste gas enters the purification box 4 through the second connecting pipe 16 under the drive of the air pump 17, and then adsorbs formaldehyde.

[0031] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A drying device for producing paraformaldehyde, characterized in that: It includes a drying chamber, the top of which is equipped with a feeding hopper, and a cooling chamber and a purification chamber are connected in sequence on the right side of the drying chamber; The drying chamber is equipped with a rotating stirring shaft inside. The axial direction of the stirring shaft is consistent with the length direction of the drying chamber. Multiple sets of drying plates are evenly distributed on the stirring shaft. Each set of drying plates is equipped with a heating tube. A cavity structure is opened at the center of both ends of the stirring shaft. The two ends of each heating tube are connected to the cavity structures on both sides respectively. The stirring shaft is rotated and sealed on the left and right sides through a first rotary joint and a second rotary joint, respectively. Both the first rotary joint and the second rotary joint are hollow structures and are connected to the cavity structures on the corresponding sides. The first rotary joint is provided with a heat-conducting medium addition pipe, and the second rotary joint is provided with a heat-conducting medium discharge pipe. A blower is located on the upper left side of the drying chamber, and a gas collection hood is located on the upper right side of the drying chamber. The right side of the gas collection hood is connected to the cooling chamber via a first connecting pipe, and the bottom of the cooling chamber is connected to the purification chamber via a second connecting pipe. A drive assembly is located on the bottom left side of the drying chamber, and the drive assembly is used to control the rotation of the stirring shaft.

2. The drying equipment for producing paraformaldehyde according to claim 1, characterized in that: The cooling box has a drain end and a water inlet end on its side. The cooling box is equipped with a vertically arranged cooling coil inside. The upper and lower ends of the cooling coil are connected to a first connecting pipe and a second connecting pipe, respectively. An air pump is fixedly installed on the second connecting pipe.

3. The drying equipment for producing paraformaldehyde according to claim 1, characterized in that: The bottom cross-section of the drying oven is a semi-circular arc structure, which is adapted to the rotation trajectory of the drying plate driven by the stirring shaft. The heating tubes are distributed in an S-shape inside the drying plate.

4. The drying equipment for producing paraformaldehyde according to claim 1, characterized in that: The drive assembly includes a drive motor connected to the bottom of the drying chamber. The output end of the drive motor is fixedly fitted with a drive pulley, and the end of the stirring shaft near the drive motor is fixedly fitted with a driven pulley. The drive pulley and the driven pulley are connected by a belt drive.

5. The drying equipment for producing paraformaldehyde according to claim 1, characterized in that: The bottom of the purification box is fixedly equipped with a horizontally arranged exhaust main pipe. The input end of the exhaust main pipe is connected to the second connecting pipe. Multiple exhaust branch pipes are evenly distributed above the exhaust main pipe, and each exhaust branch pipe is connected to the inside of the exhaust main pipe.

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