Paper pulp molding drying and heating device

Abstract

The present invention relates to the technical field of pulp molding production, and discloses a pulp molding drying and heating device, which includes a heating surface housing and a non-heating surface housing, as well as a graphene nano-heating plate arranged between the two to form a heating unit. The heating plate is fixed on the heating surface housing, an insulating paper is arranged between the heating plate and the heating surface housing, an insulating wire groove is arranged below the heating plate, wires are arranged in the insulating wire groove and connected to the heating plate, and the wires are led out from one end of the insulating wire groove to a control power supply. The present invention has high heat energy utilization rate, is safe and reliable, and is convenient to use.

Description

Technical Field

[0001] The present invention relates to the technical field of pulp molding production, and particularly to a pulp molding drying and heating device. Background Art

[0002] Currently, in China, the molds for pulp molding generally have problems such as low production efficiency, high rejection rate, high energy consumption, unstable operation of the molding machine, and relatively single products produced by the molding machine.

[0003] Most domestic manufacturers' equipment mainly uses manual machines and dry pressing. However, it is very difficult to produce high-value-added fine industrial packaging products by dry pressing. At this time, the in-mold drying (wet pressing) process must be adopted. After the mold is shaped, it is directly transferred to the drying station to complete drying and shaping together. Since the traditional moisture content of plant fibers during drying is 55-65%, relatively high heat energy is required. Moreover, for some heavy products, the heat energy of the heating plate cannot be effectively transferred to the mold, and it can only meet the production of shallow products and food packaging products with a relatively large draft angle, such as disposable discs, plates, lunch boxes, etc. With the increasing global emphasis on environmental protection and sustainable development, the social requirements for pulp molding products are constantly expanding, and new application fields are constantly developing. Even HP, Dell, and Gree have joined this industry one after another. However, in fact, few existing molding machines are capable of producing high-value-added products with an angle less than 6 degrees, such as industrial packaging products like tea packaging boxes, mobile phone holders, razors, endoscope holders, Moutai holders, coffee cups, etc., and the adaptability is poor.

[0004] The main methods of in-mold drying (wet pressing) technology for pulp molding include electric heating, steam heating, heat-conducting oil heating, etc.

[0005] Electric heating has the advantages of being clean, convenient, reliable, and easy to control temperature, and no other additional auxiliary equipment and pipelines are required. However, for the heating plate, deep-hole machining is used, and the drill bit is easily broken inside the heating plate. Electric heating is to bury the heating tube in the heating plate. However, affected by thermal expansion and contraction, the gap between the heating tube and the heating plate will be filled with air. The thermal conductivity of air is only 0.04w / m.k, and air is the best heat insulator, which reduces the thermal conductivity. The resistance conversion rate is only about 80%, and the thermal energy utilization rate is low. During the working process, a large amount of water vapor is generated during the hot pressing and shaping of the mold, which is easy to corrode the wires (especially the joints), resulting in electric leakage and unsafe production.

[0006] Steam heating has the advantages of good product appearance quality and high finished product rate. However, it has high costs and a large amount of wasted heat energy; since the steam turns into hot water after being discharged, usually these steam-water mixtures are not utilized, and thus a considerable amount of heat energy is wasted, increasing production costs. The equipment processing requirements are high, and a special steam generation device needs to be installed. The pipeline bears high pressure (when the heating plate temperature is 220 degrees, the pressure is 2.35 MPa), and the steam has a corrosive effect on the pipeline, easily causing perforation, posing potential safety hazards, and even damaging the mold.

[0007] When heating with heat transfer oil, the heat transfer oil is used in a closed-loop cycle, significantly reducing heat energy loss and having a high thermal efficiency; the heat transfer oil has low pressure, low requirements for the pressure-bearing capacity of the pipeline, and a high safety factor. The heat transfer oil heating pipeline adopts an embedded type, the mold is heated evenly, the heating speed is increased, and the production efficiency is improved. However, oil leakage may occur at the pipeline joints, posing potential safety hazards to production personnel. There are many supporting facilities, such as boilers, high-level tanks, low-level tanks, and heat transfer oil supply pipelines; the fire protection acceptance requirements are high. When the production equipment cannot operate at full load, the boiler also needs to be turned on to supply heat, resulting in a large amount of waste. The heat transfer oil carbonizes and cokes, and the heat transfer oil needs to be replaced regularly, with a large amount of work. Summary of the Invention

[0008] The purpose of the present invention is to solve the above problems and provide a pulp molding drying and heating device with high heat energy utilization rate, safety and reliability, and convenient use.

[0009] The technical solution adopted by the present invention is:

[0010] A pulp molding drying and heating device, characterized in that it includes a heating surface housing and a non-heating surface housing, and a graphene nano-heating plate disposed therebetween to form a heating unit. The heating plate is fixed on the heating surface housing, an insulating paper is disposed between the heating plate and the heating surface housing, an insulating wire groove is disposed below the heating plate, wires are disposed in the insulating wire groove and connected to the heating plate, and the wires are led out from one end of the insulating wire groove to a control power supply.

[0011] Further, the heating surface housing and the non-heating surface housing are sleeved and fixed by fastening screws around, a sealing gasket is disposed on the mating surface of the two, and a cavity is formed in the middle, and the heating plate is disposed in the cavity.

[0012] Further, the heating surface housing forms a semi-surrounding structure to cooperate with the non-heating surface housing, insulating paper and heat insulation rock wool are disposed between the insulating wire groove and the heating plate, and heat insulation rock wool is also disposed below the insulating wire groove, and the heat insulation rock wool below is fixed on the heating surface housing by a pressing plate.

[0013] Further, a heat-conducting foam layer is disposed on the insulating paper between the heating plate and the heating surface housing.

[0014] Further, an air cavity is formed between the pressing plate and the non-heating surface housing.

[0015] Further, the heating plate is formed by using a microcrystalline material or a heat-resistant ceramic as a substrate and fabricating a nano electrothermal coating on its surface, and the nano electrothermal coating faces the side of the heating surface housing.

[0016] Further, there are multiple heating units arranged in an array, and the heating surface housings and the non-heating surface housings of the multiple heating units are all integrated.

[0017] Further, a plurality of suction guide sleeves are provided on the heating surface housing, and the suction guide sleeves penetrate through the heating surface housing and the non-heating surface housing.

[0018] Further, the lead wires of each heating unit are connected in parallel and then connected to an aviation plug, and a protective cover is arranged outside the aviation plug.

[0019] Further, each heating unit is provided with a separate temperature detection point for real-time temperature monitoring.

[0020] The beneficial effects of the present invention are as follows:

[0021] (1) Using the graphene nano energy-gathering heating plate, heat and far-infrared rays are dissipated outward in the forms of radiation and heat conduction, with high heating efficiency and strong directivity;

[0022] (2) Through the large-area contact of the heating surface housing, the heat insulation material and air insulation of the non-heating surface housing, the heating of the drying surface is made more thorough and comprehensive;

[0023] (3) The sealing treatment of the heating components ensures that the influence of water vapor during the heating process on the equipment is minimized;

[0024] (4) Multiple heating plates are evenly arranged and temperature-controlled separately to ensure the temperature uniformity of the whole heating plate. Description of the Drawings

[0025] Attached Figure 1 is the front sectional view of the pulp molding drying and heating device of the present invention;

[0026] Attached Figure 2 is the sectional view of the position of a single heating plate;

[0027] Attached Figure 3 is the top sectional view of the pulp molding drying and heating device of the present invention;

[0028] Attached Figure 4 is Figure 3 the partial enlarged view of the position of the aviation plug in

[0029] Attached Figure 5 is the side sectional view of the pulp molding drying and heating device of the present invention.

[0030] The reference numerals in the drawings are respectively as follows:

[0031] 1. Heating unit; 2. Heating surface housing;

[0032] 3. Non-heating surface housing; 4. Heating plate;

[0033] 5. Gasket; 6. Insulating paper;

[0034] 7. Thermal conductive foam layer; 8. Heat insulating rock wool;

[0035] 9. Insulating wire groove; 10. Wire groove cover;

[0036] 11. Pressure plate; 12. Electric wire;

[0037] 13. Air cavity; 14. Terminal;

[0038] 15. Aviation plug; 16. Protective cover;

[0039] 17. Heat insulating pad; 18. Suction guide sleeve. Detailed implementation manners

[0040] The following will make a detailed description of the detailed implementation manners of the pulp molding drying and heating device of the present invention with reference to the drawings.

[0041] Refer to Attach Figure 1 , 3 , 5, the pulp molding drying and heating device is composed of a plurality of heating units 1 arranged in an array, and the heating units 1 are evenly arranged. Each heating unit 1 includes a heating surface housing 2, a non-heating surface housing 3, and a graphene nano heating plate 4 arranged between the two. The heating surface housing 2 forms a semi-surrounding structure and is sleeved and matched with the non-heating surface housing 3. A gasket 5 is arranged on the mating surface of the two, and a cavity is formed in the middle. The heating plate 4 is arranged in the cavity. A plurality of heating units 1 share one heating surface housing 2 and one non-heating surface housing 3, and the heating surface housing 2 and the non-heating surface housing 3 are fixed around by fastening screws.

[0042] Refer to Attach Figure 2 , the heating plate 4 is fixed in the heating surface housing 2 from below the cavity through fasteners in cooperation with insulating gaskets. An insulating paper 6 and a thermal conductive foam layer 7 are arranged between the heating plate 4 and the heating surface housing 2. An insulating paper 6 and a heat insulating rock wool 8 are arranged in sequence below the heating plate 4. An insulating wire groove 9 is arranged below the heat insulating rock wool 8, a wire groove cover 10 is arranged below the insulating wire groove 9, a heat insulating rock wool 8 is arranged closely below the wire groove cover 10, and the heat insulating rock wool 8 is fixed on the heating surface housing 2 through a pressure plate 11 below.

[0043] The heating plate 4 adopts the principle of graphene micro-molecule nano far-infrared heating. Based on the theory of "Brownian motion" by British scientists, it uses polymer energy-gathering material technology. Utilizing the intense impact and friction between carbon molecules in the variable electric field of the polymer energy-gathering material, electrical energy is instantaneously converted into infrared radiation heat energy. Microcrystalline materials and other insulation and heat-resistant materials are selected as the carrier of the micro-molecule coating material. Through the high-temperature sintering and spraying technology at 1000 °C, the heat energy is emitted in the vertical direction, effectively ensuring the directivity of the heat energy. The graphene nano energy-gathering heating plate heats up rapidly, and its own heat energy conversion rate can reach over 98%. While the resistance conversion rate of ordinary heating tubes is about 80%, the heat consumption here can be effectively increased by more than 18%. The heating plate made of polymer nano coating molecules is different from the traditional linear heating structure. The internal current is extremely small, ensuring low energy consumption of the product. It dissipates heat in two ways: conduction and infrared radiation, with stable and uniform heat dissipation, strong penetration, higher safety and reliability, and a service life of up to more than 30,000 hours.

[0044] The heat-conducting foam layer 7 has a shock-absorbing effect, preventing the generation of clamping force increase at the contact area between the heating surface housing 2 and the heating plate 4, thus damaging the heating plate 4. The preferred material for the heat-insulating rock wool 8 is aluminum silicate to achieve an effective heat-insulating effect. Through the insulating paper 6 and the heat-insulating rock wool 8, the heating plate 4 is effectively protected. The connecting wires 12 of the heating plate 4 are arranged in the insulating wire groove 9, and through the enclosure of the wire groove cover 10, the safety of the wires 12 is effectively protected.

[0045] In addition, an air cavity 13 is formed between the pressing plate 11 at the bottom and the non-heating surface housing 3. The air cavity 13 has a heat-insulating effect, allowing the heat to be dissipated as much as possible towards the side of the heating surface housing 2. In this structure, the thickness of the heating surface housing 2 is thickened to better store heat, while the thickness of the non-heating surface housing 3 is thinned, only needing to bear the increased pressure during clamping.

[0046] See the appendix Figure 2 、 4 After the wiring terminals 14 of each heating plate 4 lead out the wires 12, they are led out in parallel through their respective insulating wire grooves 9, and then introduced into the aviation plug 15. A protective cover 16 is added outside the aviation plug 15. Through sealed installation, water vapor is effectively blocked from entering, thus avoiding potential safety hazards such as electric leakage caused by a large amount of water vapor generated during the hot pressing and drying of the mold during operation.

[0047] When this device is applied to the pulp molding drying process, a heat-insulating pad 17 is coated outside both the heating surface housing 2 and the non-heating surface housing 3 to better improve the heat energy utilization rate. A number of suction guide sleeves 18 are provided on the heating surface housing 2. The suction guide sleeves 18 penetrate the heating surface housing 2 and the non-heating surface housing 3. The suction guide sleeves 18 are used for sealing during the suction of the vapor at the upper heating surface, and are introduced to an air chamber (not shown in the figure) below.

[0048] The heating plates 4 are arranged evenly, which can better ensure the temperature balance of the whole heating plate 4. Each heating plate 4 has a separate temperature measurement point for temperature detection and control, and can be monitored in real time. When any one of them has a problem, it can also be tracked in fact and effectively protected.

[0049] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A pulp molding drying and heating device, characterized in that: It includes a heating surface housing, a non-heating surface housing, and a graphene nano-heating plate disposed therebetween to form a heating unit. The heating plate is fixed to the heating surface housing. The heating surface housing and the non-heating surface housing are sleeved and fixed by fastening screws around, and a gasket is provided on the mating surface between the two to form a cavity in the middle. The heating plate is disposed in the cavity. An insulating paper is provided between the heating plate and the heating surface housing. An insulating wire groove is provided below the heating plate, and a wire is disposed in the insulating wire groove and connected to the heating plate. The wire is led out from one end of the insulating wire groove to a control power supply. The heating surface housing forms a semi-surrounding structure to cooperate with the non-heating surface housing. An insulating paper and heat-insulating rock wool are provided between the insulating wire groove and the heating plate, and heat-insulating rock wool is also provided below the insulating wire groove. The heat-insulating rock wool below is fixed to the heating surface housing by a pressing plate.

2. The pulp molding drying and heating device according to claim 1, characterized in that: A heat-conducting foam layer is provided on the insulating paper between the heating plate and the heating surface housing.

3. The pulp molding drying and heating device according to claim 1, characterized in that: An air cavity is formed between the pressing plate and the non-heating surface housing.

4. The pulp molding drying and heating device according to any one of claims 1 to 3, characterized in that: The heating plate is formed by making a nano electrothermal coating on the surface of a microcrystalline material or heat-resistant ceramic as the base material, and the nano electrothermal coating faces the side of the heating surface housing.

5. The pulp molding drying and heating device according to any one of claims 1 to 3, characterized in that: There are multiple heating units arranged in an array, and the heating surface housings and non-heating surface housings of the multiple heating units are all integrated.

6. The pulp molding drying and heating device according to claim 5, wherein: A number of suction guide sleeves are provided on the heating surface housing, and the suction guide sleeves penetrate the heating surface housing and the non-heating surface housing.

7. The pulp molding drying and heating device according to claim 5, characterized in that: The lead wires of each heating unit are connected in parallel and then connected to an aviation plug, and a protective cover is provided outside the aviation plug.

8. The pulp molding drying and heating device according to claim 5, characterized in that: Each heating unit is provided with a separate temperature detection point for real-time temperature monitoring.

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