A setting machine heat fume waste heat recovery system

Abstract

This utility model discloses a waste heat recovery system for a stenter machine, characterized by comprising several air-cooling systems, a water-sweeping system, a fresh air preheater, a stenter oven, and a rear-end dust collector system. The air-cooling systems and the fresh air preheater are connected, and the water-sweeping system is connected to both the air-cooling systems and the fresh air preheater. This waste heat recovery system utilizes the heat exchange between exhaust waste gas and fresh air. The waste gas temperature is reduced before entering the rear-end dust collector system, while the fresh air temperature is increased, serving as a clean heat source for the front and rear ovens of the stenter machine. The fresh air is preheated in the fresh air preheater to prevent cold air from directly entering the air-to-air heat exchange recovery equipment, which could cause a sharp drop in waste gas temperature and lead to the solidification and adhesion of wax and other organic matter, resulting in blockages. Hot water purging cleans the air-to-air heat exchange recovery equipment and the fresh air preheater, preventing blockages and improving the efficiency of heat energy recycling.

Description

Technical Field

[0001] This utility model belongs to the field of heat recovery technology and relates to a waste heat recovery system for heat smoke from a stenter. Background Technology

[0002] The temperature of the waste heat exhaust gas discharged during the operation of the stenter is between 130℃ and 200℃. This type of waste heat exhaust gas has many characteristics that bring great difficulties to the recovery and utilization of heat energy from the waste heat exhaust gas, specifically as follows: the emission volume is large and the temperature is high; it is easy to catch fire, posing a significant safety hazard; the composition is complex, including organic gases such as formaldehyde and benzene, dyeing auxiliaries, fiber dust, oil, smoke, and mist, and is also accompanied by a pungent and unpleasant odor; the oil fumes in the waste heat exhaust gas are easy to condense and stick together after the temperature drops, and when mixed with fiber dust, they can easily cause a fire.

[0003] Currently, the conventional method for utilizing waste heat is gas-to-gas heat exchange. The specific process is as follows: the waste heat gas discharged from the stenter exchanges heat with fresh air, and the fresh air absorbs the heat and returns to the stenter oven. In operation, a heat exchanger is commonly used to achieve this process. The high-temperature waste gas discharged from the stenter flows through the heat-absorbing side of the heat exchanger and releases heat, which is transferred to the heat-releasing side of the heat exchanger through heat pipes. When fresh air flows through the heat-releasing side of the heat exchanger, it absorbs heat, and the heated fresh air is drawn into the stenter oven by the negative pressure inside, thus achieving energy savings.

[0004] However, this single heat exchanger method has many drawbacks. First, the heat exchanger tube walls are prone to oil buildup, leading to a significant decrease in heat exchange efficiency and consequently, excessively high exhaust temperatures, increasing the risk of combustion. In the event of a fire, the high temperature will cause a severe thermal shock to the heat exchanger, and if the piping design is inadequate, it could even cause a burst. Second, the confined space and long pipes of tubular heat exchangers make cleaning extremely difficult once the tube walls are covered in oil. Over time, the entire pipeline will gradually become clogged, not only reducing thermal efficiency but also decreasing the exhaust area and increasing exhaust resistance, severely impacting the normal operation of the stenter. Therefore, a waste heat recovery system for stenter exhaust is needed to address these problems. Utility Model Content

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A heat recovery system for hot smoke from a stenter includes several air-cooling systems, a water-sweeping system, a fresh air preheater, a stenter oven, and a rear dust collector system. The air-cooling systems and the fresh air preheater are connected to each other, and the water-sweeping system is connected to both the air-cooling system and the fresh air preheater.

[0007] The air-cooling system includes a stenter exhaust fan and several air-to-air heat exchange and recovery devices. The exhaust port of the stenter exhaust fan is connected in series with several air-to-air heat exchange and recovery devices, and the air-to-air heat exchange and recovery devices are connected to the fresh air preheater.

[0008] The air-to-air heat exchange and recovery equipment and the fresh air preheater are each provided with two chambers. One chamber is for the flow of waste heat exhaust gas from the stenter, and the other chamber is for the flow of fresh air. The waste heat exhaust gas flows into the fresh air preheater through the stenter exhaust gas fan and several air-to-air heat exchange and recovery equipment, and is then introduced into the downstream dust collector system from the exhaust port of the fresh air preheater. Fresh air enters the fresh air preheater from the outside, is heated by the fresh air preheater, and is then introduced into several air-to-air heat exchange and recovery equipment, and then enters the stenter oven through the fresh air outlet of the air-to-air heat exchange and recovery equipment.

[0009] The water sweeping system includes a water pipe, a hot water purge pump, and a spray electric valve. The water pipe is connected to the hot water purge pump. The spray electric valve is installed at the upper end of the exhaust port of each of the air / gas heat exchange and recovery devices and the fresh air preheater. The end of the water pipe is connected to the spray electric valve.

[0010] As a further embodiment of this utility model: the water sweeping system further includes a tap water source, a hot water source, a hot water tank, a heating electric valve and a water replenishment electric valve. The tap water source is connected to the hot water tank through the water replenishment electric valve. The hot water source is connected to the hot water tank through the heating electric valve. The hot water tank is connected to the water pipe through the hot water purging pump.

[0011] As a further embodiment of this utility model: the water sweeping system also includes a fire water source, which is connected to the water pipe.

[0012] As a further embodiment of this utility model, it also includes a fresh air fan, through which the fresh air heated by the fresh air preheater is introduced into the air-to-air heat exchange and recovery device.

[0013] As a further embodiment of this utility model: the gas-to-gas heat exchange and recovery device includes several heat exchange plates, which are spliced ​​together to form several rectangular cavities, in which waste heat and fresh air circulate in different areas of the rectangular cavities.

[0014] As a further embodiment of this utility model, it also includes a temperature measuring device, wherein the inlet and outlet of the stenter exhaust fan, the air-to-air heat exchange and recovery equipment and the fresh air preheater are equipped with temperature measuring devices.

[0015] As a further embodiment of this utility model, it also includes negative pressure gauges, and negative pressure gauges are provided at the inlet and outlet of the stenter exhaust fan, the air-to-air heat exchange and recovery equipment and the fresh air preheater.

[0016] As a further embodiment of this utility model, it also includes an oil-sewage separation box, and the bottom of the fresh air preheater is connected to the oil-sewage separation box.

[0017] The beneficial effects of this utility model are:

[0018] A waste heat recovery system for a stenter machine involves cooling the waste gas in stages through multiple air-to-air heat exchangers. This staged cooling gradually releases the heat from the waste gas, preventing wax solidification due to sudden temperature drops. Fresh air (cold air) is introduced into the fresh air preheater, where it interacts with the exhaust waste gas, thus cooling the waste gas. The fresh air then flows in the reverse direction through the air-to-air heat exchangers, increasing its temperature and ultimately serving as a clean heat source for the stenter's front and rear ovens. This reduces the amount of steam used to heat the ovens. Furthermore, according to the ideal gas law P1V1 / T1=P2V2 / T2, a decrease in temperature reduces the waste gas volume. This allows the exhaust fan in the downstream dust collector system to operate at a reduced speed, thus reducing the system's energy consumption.

[0019] On the other hand, the fresh air is preheated in the fresh air preheater to prevent cold air from directly entering the air-to-air heat exchange and recovery equipment. This would cause a sharp drop in the temperature of the waste gas, which would lead to the solidification and adhesion of wax oil and other organic matter, resulting in blockage and affecting the long-term efficient operation of the heat exchanger.

[0020] In addition, to further optimize the utilization of thermal energy, the system is also equipped with a water purging system. Operating without affecting the original production process of the stenter, the system uses hot water to clean areas where wax or oil residue may remain, such as the air-to-air heat exchange and recovery equipment and the fresh air preheater, preventing blockages, improving the efficiency of thermal energy recycling, and ultimately saving energy. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a waste heat recovery system for a stenter machine.

[0022] Figure 2 This is a structural diagram of a gas-to-gas heat exchanger recovery device for a waste heat recovery system of a stenter;

[0023] Figure 3 This is a schematic diagram of the structure of a gas-to-gas heat exchanger combination in a waste heat recovery system for a stenter machine.

[0024] As shown in the diagram, 1-gas / gas heat exchange and recovery equipment, 101-heat exchange plate, 2-fresh air preheater, 3-styling machine exhaust fan, 4-water pipe, 5-hot water purge pump, 6-tap water source, 7-hot water source, 8-hot water tank, 9-heating electric valve, 10-water replenishment electric valve, 11-fire water source, 12-styling machine oven, 13-fresh air fan, 14-oil and sludge separation box, M1-M7-spray electric valve, F-exhaust gas, D-roof. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. It should be understood that this application is not limited to the exemplary embodiments disclosed herein. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0029] like Figure 1As shown, a heat recovery system for a stenter includes several air-cooling systems, a water-sweeping system, a fresh air preheater, a stenter oven, and a rear-end dust collector system. Several air-cooling systems are connected to the fresh air preheater, and the water-sweeping system is connected to both the air-cooling system and the fresh air preheater.

[0030] The air-cooled system includes a stenter exhaust fan and several air-to-air heat exchange and recovery devices. The exhaust port of the stenter exhaust fan is connected in series with several air-to-air heat exchange and recovery devices, which are connected to a fresh air preheater.

[0031] The air-to-air heat exchange and recovery equipment and the fresh air preheater are each equipped with two chambers. One chamber is used for the flow of waste heat exhaust gas from the stenter, and the other chamber is used for the flow of fresh air. The waste heat exhaust gas flows into the fresh air preheater through the stenter exhaust fan and several air-to-air heat exchange and recovery equipment, and is then introduced into the downstream dust collector system from the exhaust port of the fresh air preheater. Fresh air enters the fresh air preheater from the outside, is heated by the fresh air preheater, and is then introduced into several air-to-air heat exchange and recovery equipment, and finally enters the stenter oven through the fresh air outlet of the air-to-air heat exchange and recovery equipment.

[0032] The water sweeping system includes water pipes, a hot water purge pump, and a spray electric valve. The water pipes are connected to the hot water purge pump, and a spray electric valve is installed at the upper end of the exhaust port of each air / gas heat exchange recovery device and fresh air preheater. The water pipe ends are connected to the spray electric valve.

[0033] Specifically, such as Figure 1 As shown, the system has two air-cooled systems and one water-sweeping system. The fresh air preheater discharges two batches of fresh air, which enter the two air-cooled systems respectively. Each air-cooled system consists of three sets of air-to-air heat exchange and recovery devices combined together. For example... Figure 1 As shown, the flow direction of waste heat and exhaust gas is indicated by a white arrow, and the flow direction of fresh air is indicated by a black arrow.

[0034] On one hand, a waste heat recovery system for a stenter uses multiple air-to-air heat exchangers to cool the waste gas in stages. This staged cooling gradually releases the heat from the waste gas, preventing the wax from solidifying due to a sudden drop in temperature. Fresh air (cold air) is introduced into the fresh air preheater, where the exhaust waste gas interacts with the fresh air, cooling the waste gas. The fresh air then flows in the reverse direction through the air-to-air heat exchangers, increasing its temperature and ultimately serving as a clean heat source flowing into the front and rear ovens of the stenter. This reduces the amount of steam used by the stenter to heat the ovens. Simultaneously, according to the ideal gas law P1V1 / T1=P2V2 / T2, as the temperature decreases, the amount of waste gas decreases. This allows the exhaust fan in the downstream dust collector system to reduce its operating angle, thus reducing the energy consumption of the downstream dust collector system.

[0035] On the other hand, the fresh air is preheated in the fresh air preheater to prevent cold air from directly entering the air-to-air heat exchange and recovery equipment. This would cause a sharp drop in the temperature of the waste gas, which would lead to the solidification and adhesion of wax oil and other organic matter, resulting in blockage and affecting the long-term efficient operation of the heat exchanger.

[0036] In addition, to further optimize the utilization of thermal energy, the system is also equipped with a water purging system. Operating without affecting the original production process of the stenter, the system uses hot water to clean areas where wax or oil residue may remain, such as the air-to-air heat exchange and recovery equipment and the fresh air preheater, preventing blockages, improving the efficiency of thermal energy recycling, and ultimately saving energy.

[0037] In this embodiment, as Figure 1 As shown, the water sweeping system also includes a tap water source, a hot water source, a hot water tank, a heating electric valve, and a water replenishment electric valve. The tap water source is connected to the hot water tank through the water replenishment electric valve, the hot water is connected to the hot water tank through the heating electric valve, and the hot water tank is connected to the water pipe through a hot water purge pump.

[0038] Specifically, hot water is used to clean and purge areas where residual wax and oil may remain, such as the air-to-air heat exchanger and the fresh air preheater. In the steam cooling system, the water collected after steam condensation is hot water, typically reaching a temperature of around 130℃ to 150℃. The temperature can be adjusted by adding tap water to ensure the cleaning and purging water reaches the appropriate value. Due to its high temperature, the hot water dissolves residual wax and oil and other adhering substances during the water purging of the air-to-air heat exchanger and the fresh air preheater, preventing blockages. The hot water tank temperature is automatically maintained at around 90℃, a verified and suitable purging temperature. During purging, the wastewater mixture containing dissolved wax and adhering substances flows obliquely from the bottom of the air-to-air heat exchanger into the oil-water separation tank located at the bottom of the fresh air preheater. Oil and water are separated in the oil-water separation tank; the wastewater automatically overflows and is discharged, while the oil is manually cleaned periodically.

[0039] In this embodiment, as Figure 1 As shown, the water sweeping system also includes a fire water source, which is connected to a water pipe.

[0040] Specifically, a fire-fighting water source is connected in parallel to the water pipes so that in the special circumstances of fire and power failure, there is water to extinguish the fire and ensure the safe operation of the equipment.

[0041] In other embodiments, a dust filter is added to the exhaust port of the stenter body to perform preliminary filtration of the waste heat gas entering the stenter hot smoke waste heat recovery system, effectively improving the working conditions of the gas-to-gas heat exchange recovery equipment and the fresh air preheater.

[0042] In this embodiment, as Figure 1As shown, it also includes a fresh air fan, which introduces the fresh air heated by the fresh air preheater into the air-to-air heat exchange and recovery equipment.

[0043] Specifically, by adjusting the fresh air flow rate through a fresh air fan, the heated fresh air is introduced into the air-to-air heat exchange and recovery equipment, thereby improving the system's working efficiency.

[0044] In this embodiment, as Figure 2-3 As shown, the gas-to-gas heat exchange and recovery equipment includes several heat exchange plates, which are spliced ​​together to form several rectangular cavities. Waste heat and fresh air circulate in the rectangular cavities in different areas.

[0045] Specifically, the heat exchange plate is a multi-large-area flue plate structure, which is bent and spliced ​​to form multiple rectangular cavities, providing excellent heat exchange performance. The gas-to-gas heat exchange and recovery equipment and its connecting flue gas pipes are installed at a certain slope to facilitate the flow of exhaust gas and to allow the oil, wax, and adhering substances carried down after hot water washing to flow down in a timely manner and eventually flow into the oil-sludge separation box, thus avoiding clogging of the flue.

[0046] Tests showed that the high-temperature waste heat from the stenter exchanged heat with the fresh air heated at low temperature in a counter-current manner, maintaining a temperature gradient for heat transfer. The cooling effect of the waste heat and the heating effect of the fresh air were significant, and the temperature difference could be controlled within 20℃.

[0047] In this embodiment, a temperature measuring device is also included, and temperature measuring devices are provided at the inlet and outlet of the stenter exhaust fan, the air-to-air heat exchange and recovery equipment, and the fresh air preheater.

[0048] Specifically, by installing temperature measuring devices at key locations, the temperature changes at each point can be monitored in real time and timely adjustments can be made to keep the heat exchanger operating at its optimal condition.

[0049] In this embodiment, a negative pressure gauge is also included, and negative pressure gauges are installed at the inlet and outlet of the stenter exhaust fan, the air-to-air heat exchange and recovery equipment, and the fresh air preheater.

[0050] Specifically, negative pressure gauges and positive pressure gauges are installed at the inlet of the stenter exhaust fan, the inlet of the air-to-air heat exchange and recovery equipment, and the waste heat exhaust outlet of the fresh air preheater, respectively. This allows for real-time assessment of the flow conditions of the dust filter and the system, enabling timely development of maintenance plans.

[0051] In this embodiment, an oil separation box is also included, and the bottom of the fresh air preheater is connected to the oil separation box.

[0052] Specifically, wastewater from the fresh air preheater flows through pipes into an oil-water separation tank. This tank is used to separate oil and water from liquids. Its core principle is based on the density difference between oil and water, achieving effective separation through physical methods. The separated wastewater is discharged into the plant's wastewater pond, where it enters the post-treatment process along with wastewater generated during production, preventing direct discharge and environmental pollution.

[0053] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0054] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily 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 this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A waste heat recovery system for stenter machines, characterized in that, It includes several air-cooling systems, water-sweeping systems, fresh air preheaters, stenter ovens, and a back-end dust collector system. Several of the air-cooling systems and the fresh air preheaters are connected, and the water-sweeping systems are connected to the air-cooling systems and the fresh air preheaters respectively. The air-cooling system includes a stenter exhaust fan and several air-to-air heat exchange and recovery devices. The exhaust port of the stenter exhaust fan is connected in series with several air-to-air heat exchange and recovery devices, and the air-to-air heat exchange and recovery devices are connected to the fresh air preheater. The air-to-air heat exchange and recovery equipment and the fresh air preheater are each provided with two chambers. One chamber is for the flow of waste heat exhaust gas from the stenter, and the other chamber is for the flow of fresh air. The waste heat exhaust gas flows into the fresh air preheater through the stenter exhaust gas fan and several air-to-air heat exchange and recovery equipment, and is then introduced into the downstream dust collector system from the exhaust port of the fresh air preheater. Fresh air enters the fresh air preheater from the outside, is heated by the fresh air preheater, and is then introduced into several air-to-air heat exchange and recovery equipment, and then enters the stenter oven through the fresh air outlet of the air-to-air heat exchange and recovery equipment. The water sweeping system includes a water pipe, a hot water purge pump, and a spray electric valve. The water pipe is connected to the hot water purge pump. The spray electric valve is installed at the upper end of the exhaust port of each of the air / gas heat exchange and recovery devices and the fresh air preheater. The end of the water pipe is connected to the spray electric valve.

2. The heat recovery system for stenter machine waste smoke according to claim 1, characterized in that, The water sweeping system also includes a tap water source, a hot water source, a hot water tank, a heating electric valve, and a water replenishment electric valve. The tap water source is connected to the hot water tank through the water replenishment electric valve, the hot water source is connected to the hot water tank through the heating electric valve, and the hot water tank is connected to the water pipe through the hot water purging pump.

3. The heat recovery system for stenter machine waste smoke according to claim 2, characterized in that, The water sweeping system also includes a fire water source, which is connected to the water pipe.

4. The heat recovery system for stenter machine waste gas according to claim 1, characterized in that, It also includes a fresh air fan, through which the fresh air heated by the fresh air preheater is introduced into the air-to-air heat exchange and recovery equipment.

5. The heat recovery system for stenter machine waste gas according to claim 1, characterized in that, The gas-to-gas heat exchange and recovery equipment includes several heat exchange plates, which are spliced ​​together to form several rectangular cavities, in which waste heat and fresh air circulate in different areas of the rectangular cavities.

6. The heat recovery system for stenter machine waste gas according to claim 1, characterized in that, It also includes temperature measuring devices, with temperature measuring devices installed at the inlet and outlet of the stenter exhaust fan, the air-to-air heat exchange and recovery equipment, and the fresh air preheater.

7. The heat recovery system for stenter machine waste gas according to claim 1, characterized in that, It also includes negative pressure gauges, and the inlet and outlet of the stenter exhaust fan, the air-to-air heat exchange and recovery equipment and the fresh air preheater are equipped with negative pressure gauges.

8. The heat recovery system for stenter machine waste gas according to claim 1, characterized in that, It also includes an oil separation box, and the bottom of the fresh air preheater is connected to the oil separation box.

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