A hot air drying oven

Abstract

The utility model relates to a hot -blast drying oven, especially a hot -blast drying oven's air drying device, include: heat exchanger, exhaust fan is connected with the waste gas export of heat exchanger, exhaust main pipe is connected with the waste gas import of heat exchanger, exhaust branch pipe is connected with exhaust main pipe and oven respectively, mixed air box, inside is equipped with first heater, with the first air outlet of heat exchanger and exhaust main pipe are connected, fresh air fan, is located on the second air outlet of mixed air box, fresh air main pipe is connected with the third air outlet of fresh air fan, fresh air branch pipe is connected with fresh air main pipe, heating oven, inside is equipped with second heater, with fresh air branch pipe and exhaust branch pipe are connected respectively, circulating fan is connected with heating oven and oven respectively. The utility model provides a kind of hot -blast drying oven's air drying device to realize low concentration exhaust circulation utilization, increase exhaust concentration, reduce exhaust volume, exhaust heat recycling, reduce energy consumption and operating cost.

Description

Technical Field

[0001] This utility model relates to a hot air drying oven, and more particularly to a drying device for a hot air drying oven. Background Technology

[0002] In the flexible packaging industry, each unit of the hot air drying oven in a printing press is designed for maximum production speed, full-page printing, and maximum page width. However, in actual production, it is extremely difficult to determine the production speed, whether the print is full-page, and whether the product is at its maximum page width. Precise matching of processes is impossible, and oven operation cannot be precisely controlled. Even at low speeds, narrow widths, and with incomplete printing, high airflow is used, and exhaust air is not recycled and directly discharged to the downstream waste gas treatment equipment, resulting in a huge waste of air volume and heat. At the same time, waste gases containing various solvents must meet national emission standards before being released into the atmosphere. The larger the exhaust volume, the higher the cost of downstream waste gas treatment and operating costs. Therefore, waste gas treatment is a problem that all printing companies must face, especially domestically produced equipment, which has large exhaust volumes, low concentrations, and high energy consumption. Effective waste gas treatment not only meets national emission standards but, more importantly, effectively reduces energy consumption and saves operating costs. Utility Model Content

[0003] To solve the above problems, this utility model provides a drying device for a hot air drying oven, the specific technical solution of which is as follows: A drying device for a hot air drying oven includes: a heat exchanger; an exhaust fan connected to the exhaust gas outlet of the heat exchanger; a main exhaust pipe connected to the exhaust gas inlet of the heat exchanger; exhaust branch pipes connected to the main exhaust pipe and the oven respectively; a mixing chamber with a first heater inside, connected to the first air outlet of the heat exchanger and the main exhaust pipe; a fresh air fan located at the second air outlet of the mixing chamber; a main fresh air pipe connected to the third air outlet of the fresh air fan; a fresh air branch pipe connected to the main fresh air pipe; a heating chamber with a second heater inside, connected to the fresh air branch pipe and the exhaust branch pipe respectively; and a circulating fan connected to the heating chamber and the oven respectively.

[0004] Preferably, it also includes: a branch exhaust valve, which is installed on the exhaust branch pipe and is used to control the return air volume and exhaust air volume of the oven.

[0005] Furthermore, it also includes: a branch air inlet valve, which is installed on the fresh air branch pipe and is used to control the amount of fresh air entering the oven.

[0006] Furthermore, it also includes: a return air duct, which is connected to the heating box and the exhaust branch duct respectively.

[0007] Furthermore, it also includes a second concentration detector, which is installed on the return air duct.

[0008] Preferably, it further includes: a total concentration detector, installed on the main exhaust pipe; and a main exhaust valve, installed on the main exhaust pipe.

[0009] Furthermore, it also includes: a main air inlet valve, located on the second air outlet of the mixing box.

[0010] Furthermore, it also includes a second air inlet valve, which is located on the second air inlet pipe of the mixing box.

[0011] Preferably, it further includes: an air supply duct, which is connected to the oven and the circulating fan respectively.

[0012] Preferably, the fresh air branch pipe is located before the second heater.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a drying device for a hot air drying oven, which realizes the recycling of low-concentration exhaust air, increases the exhaust air concentration, reduces the exhaust air volume, and recovers and utilizes exhaust air heat, thereby reducing energy consumption and operating costs. Attached Figure Description

[0014] Figure 1 This is a front view of this application; Figure 2 This is a stereoscopic view from the first perspective of this application; Figure 3 This is a stereoscopic view from the second perspective of this application; Figure 4 This is a magnified view of the application from below; Figure 5 This is a partial enlarged view of this application; Figure 6 This is a schematic diagram of the heat exchanger. Figure 7 This is a schematic diagram of the mixing box. Detailed Implementation

[0015] The present invention will now be further described with reference to the accompanying drawings.

[0016] like Figures 1 to 7 As shown, a drying device for a hot air drying oven includes a heat exchanger 1, an exhaust fan 2, an exhaust main pipe 31, an exhaust branch pipe 32, a mixing box 4, a fresh air fan 5, a fresh air main pipe 51, a fresh air branch pipe 52, a heating box 6, a circulating fan 7, a branch air inlet valve 53, a total concentration detector 81, and a main exhaust valve 82. The heat exchanger 1 is provided with a first air inlet 14, a first air outlet 13, an exhaust gas outlet 11 and an exhaust gas inlet 12. The heat exchanger 1 realizes heat exchange between fresh air and exhaust gas. The high temperature of the exhaust gas preheats the air, thereby improving the utilization rate of thermal energy.

[0017] The mixing box 4 is provided with a second air inlet 41 and a second air outlet 42.

[0018] The air inlet of the oven 9 is connected to the circulating fan 7 via the air supply pipe 71. The circulating fan 7 is connected to the third outlet after the second heater 62 of the heating box 6. The second heater 62 is installed inside the heating box 6 and is located in front of the circulating fan 7. The heating box 6 is connected to the fresh air branch pipe 52 and is located behind the fresh air branch pipe 52 to heat the fresh air. The bottom of the heating box 6 is connected to the exhaust branch pipe 32 via the return air pipe 61 and is located behind the return air pipe 61 to heat the return air. The exhaust branch pipe 32 is connected to the exhaust main pipe 31.

[0019] The fresh air branch pipe 52 is connected to the fresh air main pipe 51, the fresh air main pipe 51 is connected to the air outlet of the fresh air fan 5, and the air inlet of the fresh air fan 5 is connected to the second air outlet 42 of the mixing box 4.

[0020] A branch exhaust valve 33 is installed on the exhaust branch pipe 32. The branch exhaust valve 33 is used to control the return air volume and exhaust air volume of the oven 9. The branch inlet valve 53 is installed on the fresh air branch pipe 52 and is used to control the fresh air volume entering the oven 9.

[0021] The second inlet of the mixing box 4 is connected to the exhaust pipe 31 via the second inlet pipe 43, and is used to draw in the exhaust gas in the exhaust pipe 31. The second inlet pipe 43 is equipped with a second inlet valve 84, which is used to control the amount of exhaust gas entering.

[0022] The second fresh air inlet 41 of the mixing box 4 is connected to the first air outlet 13 of the heat exchanger 1. The second heater 62 is installed inside the mixing box 4 to heat the mixed air of fresh air and exhaust gas inside the mixing box 4 so that the temperature of the mixed air reaches the set temperature.

[0023] The total concentration detector 81 is installed on the exhaust main pipe 31; the main exhaust valve 82 is installed on the exhaust main pipe 31.

[0024] After printing, the substrate enters the oven 9 through the substrate inlet. The hot air sent to the oven 9 dries the solvent carried by the substrate and removes the solvent. The dried substrate leaves the oven 9 through the substrate outlet and enters the next printing unit for a new printing and drying process.

[0025] The circulating fan 7 delivers hot air from the heating box 6 into the drying oven 9 through the air supply pipe 71. The organic solvent is dried by the hot air inside the drying oven 9 and evaporates into the air inside the oven 9. As the air exits the drying oven 9 through the return air vent, some of the air returns to the heating box 6 through the return air pipe 61 for reheating and reuse, while some air enters the main exhaust pipe 31 through the exhaust branch pipe 32. The branch exhaust valve 33 controls the return and exhaust air volume of each printing unit. All the exhaust gas from multiple printing units converges into the main exhaust pipe 31, resulting in a total concentration... The detector 81 measures the concentration level of organic solvents in the total exhaust air. If the solvent concentration level is lower than the set value, the total exhaust valve 82 closes slightly, and the low-concentration air returns to the printing press system for recycling through the second inlet of the mixing box 4. When the concentration value of the total exhaust air is increased to the set value, it enters the exhaust fan 2 and is sent to the downstream waste gas treatment equipment. When the concentration reaches a suitable value, the downstream waste gas treatment equipment can maintain its operation by the heat generated by solvent combustion, without consuming additional energy to burn the waste gas, thus reducing the energy consumption required for waste gas treatment. At the same time, a heat exchanger 1 is installed at the inlet end of the exhaust fan 2. The exhaust gas passes through the heat exchanger 1 and exchanges heat with the fresh air before entering the exhaust fan 2, which then sends it to the downstream exhaust gas treatment equipment. When the exhaust gas carrying solvent is discharged from the printing press, an appropriate amount of fresh air needs to be replenished into the printing press. The replenished fresh air exchanges heat with the exhaust gas through heat exchanger 1 and then enters the mixing box 4, where it mixes with the exhaust gas delivered by the exhaust main pipe 31. The mixing box 4 is equipped with a first heater 49. After the mixed air is heated to a certain temperature by the first heater 49, it is sent to the heating box 6 of each printing unit through the fresh air fan 5, the fresh air main pipe 51, and the fresh air branch pipe 52. The fresh air inlet of the heating box 6 and the fresh air branch pipe 52 are directly equipped with branch air inlet valves 53 to control the amount of fresh air entering a single printing unit. Each printing unit heating box 6 is equipped with an independent second heater 62. After the mixed air is heated to the set temperature of the single process by the second heater 62, it enters the drying oven 9 through the circulating fan 7 and the air supply pipe 71 to dry the solvent and remove the solvent. The air then undergoes the next circulation. Through the recycling of air, a state of high concentration and low exhaust volume is finally achieved in the exhaust gas treatment equipment.

[0026] Each printing unit's branch exhaust valve 33 and branch inlet valve 53 can be controlled manually or automatically, depending on the process. Manual control saves equipment costs and is easy to operate; automatic control can improve accuracy and automation, and save energy.

[0027] Furthermore, an independent second concentration detector can be installed on the exhaust branch pipe 32, which is linked with the branch air inlet valve 53 and the branch exhaust valve 33 to achieve the discharge of a single printing unit when the concentration reaches the set concentration value, thereby further and thoroughly solving the problem of exhaust volume and energy consumption of the printing unit drying system.

[0028] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without inventive effort, and these embodiments will all fall within the protection scope of the claims of this utility model.

Claims

1. A drying device for a hot air drying oven, characterized in that, include: Heat exchanger (1); An exhaust fan (2) is connected to the exhaust gas outlet (11) of the heat exchanger (1); The exhaust pipe (31) is connected to the exhaust gas inlet (12) of the heat exchanger (1); The exhaust branch pipe (32) is connected to the exhaust main pipe (31) and the oven (9) respectively; The mixing box (4) is equipped with a first heater (49) inside and is connected to the first air outlet (13) of the heat exchanger (1) and the exhaust pipe (31); The fresh air fan (5) is located at the second air outlet (42) of the mixing box (4); The fresh air main pipe (51) is connected to the third air outlet of the fresh air fan (5); Fresh air branch pipe (52) is connected to the fresh air main pipe (51); The heating box (6) is equipped with the second heater (62) and is connected to the fresh air branch pipe (52) and the exhaust branch pipe (32) respectively; A circulating fan (7) is connected to the heating box (6) and the drying oven (9), respectively.

2. The drying device for a hot air drying oven according to claim 1, characterized in that, Also includes: A branch exhaust valve (33) is installed on the exhaust branch pipe (32) and is used to control the return air volume and exhaust air volume of the oven (9).

3. The drying device of a hot air drying oven according to claim 2, characterized in that, Also includes: A branch air inlet valve (53) is installed on the fresh air branch pipe (52) to control the amount of fresh air entering the oven (9).

4. The drying device of a hot air drying oven according to claim 3, characterized in that, Also includes: The return air duct (61) is connected to the heating box (6) and the exhaust branch duct (32) respectively.

5. The drying device for a hot air drying oven according to claim 4, characterized in that, Also includes: The second concentration detector is installed on the return air duct (61).

6. The drying device for a hot air drying oven according to claim 1, characterized in that, Also includes: A total concentration detector (81) is installed on the exhaust duct (31); as well as The main exhaust valve (82) is located on the main exhaust pipe (31).

7. The drying device for a hot air drying oven according to claim 6, characterized in that, Also includes: The main air inlet valve (83) is located on the second air outlet (42) of the mixing box (4).

8. The drying device for a hot air drying oven according to claim 6, characterized in that, Also includes: The second air inlet valve (84) is located on the second air inlet pipe (43) of the mixing box (4).

9. The drying device for a hot air drying oven according to claim 1, characterized in that, Also includes: The air supply duct (71) is connected to the oven (9) and the circulating fan (7), respectively.

10. The drying apparatus of a hot air drying oven according to any one of claims 1 to 6, characterized in that, The fresh air branch pipe (52) is located before the second heater (62).

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