Fresh air preheating energy-saving conveying system

Abstract

The utility model relates to the technical field of air supplement of a polyester film transverse stretcher, in particular to a fresh air preheating energy-saving conveying system which comprises a gas-liquid heat exchange device, a gas-gas heat exchanger and a connecting pipeline. The gas-liquid heat exchange device is provided with a water inlet, a water outlet, a primary heat exchange gas inlet and a primary heat exchange gas outlet, the primary heat exchange gas inlet and the primary heat exchange gas outlet are communicated with external atmosphere, the water inlet is communicated with a hot water outlet of the boiler through a pipeline, and the water outlet is communicated with the water collection tank through a pipeline; the gas-gas heat exchanger is provided with a secondary heat exchange gas inlet, a secondary heat exchange gas outlet and a hot gas inlet, the hot gas inlet is communicated with the hot air output pipeline, and the secondary heat exchange gas outlet is communicated with the fresh air input pipeline; the connecting pipeline is arranged between the gas-liquid heat exchange device and the gas-gas heat exchanger, one end of the connecting pipeline communicates with the primary heat exchange gas outlet, and the other end of the connecting pipeline communicates with the secondary heat exchange gas inlet. The fresh air preheating energy-saving conveying system can preheat fresh air supplemented into the transverse stretching machine.

Description

Technical Field

[0001] The utility model relates to the technical field of air supply for a polyester film transverse stretching machine, and more specifically to a fresh air preheating and energy-saving conveying system. Background Art

[0002] BOPET film is a biaxially oriented polyester film with advantages such as transparency, high strength, high rigidity and high gloss. The transverse stretching process of its production line is carried out in a transverse stretching machine. When the polyester film is stretched transversely, a large amount of dust and oligomers will be generated. These dust and oligomers will be deposited on the polyester film, which will seriously affect the quality of the film and make the produced polyester film fail to meet the standards. Therefore, it is necessary to continuously discharge hot air containing dust and oligomers in the transverse stretching machine and replenish fresh air from the outside to reduce the concentration of dust and oligomers in the factory.

[0003] In order to ensure the normal progress of the transverse stretching process of polyester film, the ambient temperature in the transverse stretching machine needs to be controlled between 30°-60°, so the fresh air entering the transverse stretching machine needs to be preheated; in addition, the hot air discharged from the transverse stretching machine is also a waste of heat energy.

[0004] Therefore, how to provide a fresh air preheating and energy-saving conveying system that can preheat the fresh air supplied to the transverse stretching machine and effectively utilize the waste heat of the hot air discharged by the transverse stretching machine to save heat energy is a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0005] In view of this, in order to solve the technical problem in the prior art that the fresh air supplied to the transverse stretching machine needs to be preheated, the hot air discharged by the transverse stretching machine will cause waste of heat energy, and the waste heat in the discharged hot air needs to be effectively utilized, the utility model provides a fresh air preheating energy-saving conveying system.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A fresh air preheating and energy-saving conveying system comprises a hot air output pipe and a fresh air input pipe connected to a transverse stretching machine, a boiler and a water collecting tank, and also comprises an air-liquid heat exchange device, an air-to-air heat exchanger and a connecting pipe; the air-liquid heat exchange device comprises a water inlet, a water outlet, a primary heat exchange air inlet and a primary heat exchange air outlet connected to the external atmosphere, the water inlet is connected to the hot water outlet of the boiler through a pipe, and the water outlet is connected to the water collecting tank through a pipe; the air-to-air heat exchanger comprises a secondary heat exchange air inlet, a secondary heat exchange air outlet and a hot gas inlet, the hot gas inlet is connected to the hot air output pipe, and the secondary heat exchange air outlet is connected to the fresh air input pipe; the connecting pipe is arranged between the air-liquid heat exchange device and the air-to-air heat exchanger, one end of which is connected to the primary heat exchange air outlet, and the other end is connected to the secondary heat exchange air inlet.

[0008] The utility model provides a fresh air preheating and energy-saving conveying system, in which fresh air from the outside atmosphere enters the gas-liquid heat exchange device through a primary heat exchange air inlet, and performs an initial heat exchange with hot water introduced into the gas-liquid heat exchange device from a boiler, and after the initial heat exchange of the fresh air, enters the gas-to-gas heat exchanger through a connecting pipe for a secondary heat exchange with the hot air discharged from a transverse stretching machine, and after the secondary heat exchange, the fresh air enters the transverse stretching machine through a fresh air input pipe. The fresh air preheating and energy-saving conveying system of the utility model can not only preheat the fresh air supplemented into the transverse stretching machine, but also reduce the waste of heat energy in the hot air discharged from the transverse stretching machine, thereby effectively saving energy.

[0009] Preferably, a fresh air preheating and energy-saving delivery system also includes a connecting pipe and a gas proportional control valve 1 and a gas proportional control valve 2 for controlling the direction of the airflow. The connecting pipe is connected in parallel with the air-to-air heat exchanger, one end of which is connected to the connecting pipe, and the other end is connected to the fresh air input pipe. The gas proportional control valve 1 is installed on the connecting pipe, and the gas proportional control valve 2 is installed on one end of the connecting pipe close to the secondary heat exchange gas inlet; temperature sensors are installed on both the end of the connecting pipe close to the primary heat exchange gas outlet and the fresh air input pipe.

[0010] The beneficial effect of adopting the above technical scheme is that after the fresh air from the outside atmosphere enters the gas-liquid heat exchange device and the initial heat exchange is completed, if the fresh air after the heat exchange meets the temperature requirements in the transverse stretching machine, it will enter the transverse stretching machine through the connecting pipe and the fresh air input pipe in turn; if the fresh air after the heat exchange cannot meet the temperature requirements in the transverse stretching machine, it will enter the gas-to-gas heat exchanger for secondary heat exchange with the hot air discharged from the transverse stretching machine, and then enter the transverse stretching machine through the fresh air input pipe.

[0011] Preferably, the gas-liquid heat exchange device includes a box body, a fan and a surface cooler for gas-liquid heat exchange; the primary heat exchange gas inlet and the primary heat exchange gas outlet are respectively opened on two oppositely arranged side walls of the box body; the fan is installed in the box body, and the air inlet of the fan corresponds to the primary heat exchange gas inlet, and the air outlet of the fan corresponds to the primary heat exchange gas outlet; the surface cooler is installed in the box body and arranged between the fan and the primary heat exchange gas inlet; the water inlet and the water outlet both correspond to the surface cooler opened on the side wall of the box body, and the water inlet and the water outlet respectively correspond to the water inlet pipe and the drain pipe connected to the surface cooler.

[0012] The beneficial effect of adopting the above technical solution is that the fan draws in fresh air from the outside atmosphere through the primary heat exchange inlet on the box body, and the fresh air passes through the outer wall of the metal pipe of the surface cooler in the box body to perform the initial heat exchange with the hot water in the metal pipe, and the fan and surface cooler in the box body are reasonably arranged.

[0013] Preferably, the gas-liquid heat exchange device also includes a primary filter, a medium filter and a high efficiency filter, the primary filter and the medium filter are arranged between the surface cooler and the primary heat exchange gas inlet, and the high efficiency filter is arranged between the fan and the primary heat exchange gas outlet; the peripheral side ends of the primary filter, the medium filter and the high efficiency filter are all fixed on the inner wall of the box.

[0014] The beneficial effect of adopting the above technical solution is that the primary filter, medium filter and high efficiency filter installed in the box can filter dust or other impurities in the fresh air, preventing the fresh air carrying dust or impurities from entering the transverse stretching machine to contaminate the polyester film.

[0015] Preferably, the gas-to-gas heat exchanger further comprises a waste gas outlet, the waste gas outlet is connected to an exhaust pipe, and a cyclone separator is installed on the exhaust pipe.

[0016] The beneficial effect of adopting the above technical solution is that the hot air discharged from the transverse stretching machine can pass through the cyclone separator to remove solid particle impurities and avoid environmental pollution.

[0017] Preferably, a liquid proportional control valve is installed on the pipeline connecting the water inlet of the gas-liquid heat exchange device to the boiler.

[0018] Preferably, a pressure transmitter is installed on the fresh air input duct of the transverse stretching machine.

[0019] Preferably, a fresh air preheating and energy-saving delivery system also includes a PLC control cabinet, and the gas proportional control valve one, gas proportional control valve two, temperature sensor, liquid proportional control valve, pressure transmitter and fan are all electrically connected to the PLC control cabinet.

[0020] The beneficial effect of adopting the above technical solution is that the PLC control cabinet can automatically control the opening and closing of the gas proportional control valve 1, the gas proportional control valve 2 and the liquid proportional control valve, and the degree of automation is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the overall structure of a fresh air preheating and energy-saving conveying system of the utility model;

[0023] Figure 2 This is a schematic diagram of the structure of the gas-to-gas heat exchanger of the utility model;

[0024] Figure 3 It is a structural schematic diagram of the gas-liquid heat exchange device of the utility model.

[0025] In the attached drawings, 100-hot air output pipe, 200-fresh air input pipe, 300-boiler, 400-water collecting tank, 1-gas-liquid heat exchange device, 11-water inlet, 12-water outlet, 13-primary heat exchange gas inlet, 14-primary heat exchange gas outlet, 15-fan, 16-surface cooler, 17-primary filter, 18-medium efficiency filter, 19-high efficiency filter, 2-gas-gas heat exchanger, 21-secondary heat exchange gas inlet, 22-secondary heat exchange gas outlet, 23-hot gas inlet, 24-waste gas outlet, 3-connecting pipe, 4-connecting pipe, 5-gas proportional control valve one, 6-gas proportional control valve two, 7-temperature sensor, 8-liquid proportional control valve, 9-pressure transmitter. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 on the present invention.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] See attached Figures 1 to 3 , which is a fresh air preheating energy-saving conveying system of the utility model, including a hot air output pipeline 100 and a fresh air input pipeline 200, a boiler 300 and a water collecting tank 400 connected to the transverse stretching machine, and also includes a gas-liquid heat exchange device 1, an air-to-gas heat exchanger 2 and a connecting pipeline 3; the gas-liquid heat exchange device 1 has a water inlet 11, a water outlet 12, a primary heat exchange gas inlet 13 connected to the external atmosphere, and a primary heat exchange gas outlet 14, the water inlet 11 is connected to the hot water outlet of the boiler 300 through a pipeline, and the water outlet 12 is connected to the water collecting tank 400 through a pipeline; the air-to-gas heat exchanger 2 has a secondary heat exchange gas inlet 21, a secondary heat exchange gas outlet 22 and a hot gas inlet 23, the hot gas inlet 23 is connected to the hot air output pipeline 100, and the secondary heat exchange gas outlet 22 is connected to the fresh air input pipeline 200; the connecting pipeline 3 is arranged between the gas-liquid heat exchange device 1 and the air-to-gas heat exchanger 2, one end of which is connected to the primary heat exchange gas outlet 14, and the other end is connected to the secondary heat exchange gas inlet 21.

[0030] Specifically, the gas-to-gas heat exchanger is a plate-warp type gas-to-gas heat exchanger.

[0031] In some embodiments, a fresh air preheating energy-saving delivery system also includes a connecting pipe 4 and a gas proportional control valve 1 5 and a gas proportional control valve 2 6 for controlling the direction of the airflow. The connecting pipe 4 is connected in parallel with the air-to-air heat exchanger 2, one end of which is connected to the connecting pipe 3, and the other end is connected to the fresh air input pipe 200. The gas proportional control valve 1 5 is installed on the connecting pipe 4, and the gas proportional control valve 2 6 is installed on one end of the connecting pipe 3 near the secondary heat exchange gas inlet 21; temperature sensors 7 are installed on both the end of the connecting pipe 3 near the primary heat exchange gas outlet 14 and the fresh air input pipe 200.

[0032] In other embodiments, the gas-liquid heat exchange device 1 includes a box body, a fan 15 and a surface cooler 16 for gas-liquid heat exchange; the primary heat exchange gas inlet 13 and the primary heat exchange gas outlet 14 are respectively opened on two oppositely arranged side walls of the box body; the fan 15 is installed in the box body, and the air inlet of the fan 15 corresponds to the primary heat exchange gas inlet 13, and the air outlet of the fan 15 corresponds to the primary heat exchange gas outlet 14; the surface cooler 16 is installed in the box body and arranged between the fan 15 and the primary heat exchange gas inlet 13; the water inlet 11 and the water outlet 12 both correspond to the surface cooler 16 opened on the side wall of the box body, and the water inlet 11 and the water outlet 12 respectively correspond to the water inlet pipe and the drain pipe connected to the surface cooler 16.

[0033] Specifically, the model of the surface cooler is DHT-10AS.

[0034] In some specific examples, the gas-liquid heat exchange device 1 also includes a primary filter 17, a medium efficiency filter 18 and a high efficiency filter 19. The primary filter 17 and the medium efficiency filter 18 are arranged between the surface cooler 16 and the primary heat exchange gas inlet 13, and the high efficiency filter 19 is arranged between the fan 15 and the primary heat exchange gas outlet 14; the peripheral side ends of the primary filter 17, the medium efficiency filter 18 and the high efficiency filter 19 are all fixed on the inner wall of the box.

[0035] Specifically, the gas-to-gas heat exchanger 2 further has an exhaust gas outlet 24 , and the exhaust gas outlet 24 is connected to an exhaust pipe, and a cyclone separator is installed on the exhaust pipe.

[0036] Specifically, a liquid proportional control valve 8 is installed on the pipeline connecting the water inlet 11 of the gas-liquid heat exchange device 1 to the boiler 300 .

[0037] Specifically, a pressure transmitter 9 is installed on the fresh air input duct 200 of the transverse stretching machine.

[0038] In other specific examples, a fresh air preheating and energy-saving delivery system also includes a PLC control cabinet, and gas proportional control valve 1 5, gas proportional control valve 2 6, temperature sensor 7, liquid proportional control valve 8, pressure transmitter 9 and fan 15 are all electrically connected to the PLC control cabinet.

[0039] Among them, the pressure transmitter can detect the wind pressure in the fresh air input duct; after the gas-liquid heat exchange device has been used for a period of time, dust will accumulate on the primary filter, medium filter and high-efficiency filter, resulting in a decrease in the fresh air pressure of the fresh air input duct entering the transverse stretching machine. When the pressure transmitter detects that the wind pressure in the fresh air input duct has decreased, the signal of the reduced wind pressure is transmitted to the PLC control cabinet, and the PLC control cabinet can control the fan to increase the output power and increase the air supply pressure.

[0040] The utility model is a fresh air preheating energy-saving conveying system, which is divided into the following steps when in use:

[0041] Step 1: manually set the detection values ​​of two temperature sensors through the PLC control cabinet;

[0042] Step 2: Close the liquid proportional control valve to prevent hot water from entering the surface cooler. The fresh air from the outside atmosphere will not be heated when passing through the gas-liquid heat exchange device. Open gas proportional control valve 1 and gas proportional control valve 2. At this time, after the fresh air flows out of the gas-liquid heat exchange device, part of it enters the gas-to-gas heat exchanger and exchanges heat with the hot air discharged from the transverse stretching machine, and then enters the fresh air input pipe. Part of it directly enters the fresh air input pipe through the connecting pipe. If the fresh air temperature in the fresh air input pipe is lower than the temperature detection value, reduce the opening ratio of gas proportional control valve 1 and increase the opening ratio of gas proportional control valve 2.

[0043] Step three, when the gas proportional control valve 2 is fully opened and the gas proportional control valve 1 is fully closed, if the fresh air temperature in the fresh air input pipe is still lower than the temperature detection value, open the liquid proportional control valve to allow the hot water discharged from the boiler to enter the surface cooler, and the fresh air from the outside atmosphere passes through the gas-liquid heat exchange device and the gas-to-gas heat exchanger for two heat exchanges before entering the transverse stretching machine through the fresh air input pipe.

[0044] In steps one to three, the temperature of the hot water discharged from the boiler is 85°-95°, and the PLC control cabinet can automatically control the opening and closing of gas proportional control valve one, gas proportional control valve two and liquid proportional control valve.

[0045] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fresh air preheating energy-saving conveying system, comprising a hot air output pipe (100) and a fresh air input pipe (200) connected to a transverse stretching machine, a boiler (300) and a water collecting tank (400), characterized in that: Also includes: A gas-liquid heat exchange device (1), the gas-liquid heat exchange device (1) comprising a water inlet (11), a water outlet (12), a primary heat exchange gas inlet (13) connected to the external atmosphere, and a primary heat exchange gas outlet (14), the water inlet (11) being connected to the hot water outlet of the boiler (300) through a pipeline, and the water outlet (12) being connected to the water collecting tank (400) through a pipeline; An air-to-air heat exchanger (2), the air-to-air heat exchanger (2) having a secondary heat exchange air inlet (21), a secondary heat exchange air outlet (22) and a hot gas inlet (23), the hot gas inlet (23) being in communication with the hot air output duct (100), and the secondary heat exchange air outlet (22) being in communication with the fresh air input duct (200); A connecting pipe (3), the connecting pipe (3) is arranged between the gas-liquid heat exchange device (1) and the gas-to-gas heat exchanger (2), one end of which is connected to the primary heat exchange gas outlet (14) and the other end of which is connected to the secondary heat exchange gas inlet (21).

2. A fresh air preheating energy-saving delivery system according to claim 1, characterized in that: It also includes a connecting pipe (4) and a gas proportional control valve 1 (5) and a gas proportional control valve 2 (6) for controlling the flow direction of the air flow. The connecting pipe (4) is connected in parallel with the air-to-air heat exchanger (2), one end of which is connected to the connecting pipe (3) and the other end of which is connected to the fresh air input pipe (200). The gas proportional control valve 1 (5) is installed on the connecting pipe (4), and the gas proportional control valve 2 (6) is installed on one end of the connecting pipe (3) close to the secondary heat exchange air inlet (21); a temperature sensor (7) is installed on one end of the connecting pipe (3) close to the primary heat exchange air outlet (14) and on the fresh air input pipe (200).

3. A fresh air preheating energy-saving delivery system according to claim 1, characterized in that: The gas-liquid heat exchange device (1) comprises: A box body, wherein the primary heat exchange gas inlet (13) and the primary heat exchange gas outlet (14) are respectively opened on two oppositely arranged side walls of the box body; A fan (15), the fan (15) being installed in the housing, and the air inlet of the fan (15) corresponds to the primary heat exchange air inlet (13), and the air outlet of the fan (15) corresponds to the primary heat exchange air outlet (14); A surface cooler (16) for gas-liquid heat exchange, the surface cooler (16) is installed in the box body and arranged between the fan (15) and the primary heat exchange gas inlet (13); the water inlet (11) and the water outlet (12) are both opened on the side wall of the box body corresponding to the surface cooler (16), and the water inlet (11) and the water outlet (12) respectively correspond to the water inlet pipe and the water outlet pipe connected to the surface cooler (16).

4. A fresh air preheating energy-saving delivery system according to claim 3, characterized in that: The gas-liquid heat exchange device (1) further comprises a primary filter (17), a medium filter (18) and a high efficiency filter (19); the primary filter (17) and the medium filter (18) are arranged between the surface cooler (16) and the primary heat exchange gas inlet (13); the high efficiency filter (19) is arranged between the fan (15) and the primary heat exchange gas outlet (14); the peripheral side ends of the primary filter (17), the medium filter (18) and the high efficiency filter (19) are all fixed on the inner side wall of the box body.

5. A fresh air preheating energy-saving delivery system according to claim 1, characterized in that: The gas-to-gas heat exchanger (2) also has a waste gas outlet (24), the waste gas outlet (24) is connected to an exhaust pipe, and a cyclone separator is installed on the exhaust pipe.

6. A fresh air preheating energy-saving delivery system according to claim 2, characterized in that: A liquid proportional control valve (8) is installed on the pipeline connecting the water inlet (11) of the gas-liquid heat exchange device (1) to the boiler (300).

7. A fresh air preheating energy-saving delivery system according to claim 6, characterized in that: A pressure transmitter (9) is installed on the fresh air input pipe (200) of the transverse stretching machine.

8. A fresh air preheating energy-saving delivery system according to claim 7, characterized in that: It also includes a PLC control cabinet, and the gas proportional control valve 1 (5), the gas proportional control valve 2 (6), the temperature sensor (7), the liquid proportional control valve (8), the pressure transmitter (9) and the fan (15) are all electrically connected to the PLC control cabinet.

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