Drying and cooling waste heat recovery system and grain and oil processing production line

Abstract

The invention relates to the field of grain and oil processing, and provides a drying and cooling waste heat recovery system and a grain and oil processing production line, comprising a hot air circulation unit, a first waste heat recovery unit and a second waste heat recovery unit. The hot air circulation unit forms a hot air closed circulation loop, the first waste heat recovery unit recycles the DC waste gas waste heat to generate hot air, and the second waste heat recovery unit recycles the DC waste gas waste heat to generate new steam. Thus, the DC waste gas leaves the drying and cooling device, passes through the dust removal device, the first waste heat recovery unit, the second waste heat recovery unit and the hot air power device and then is sent back to the drying and cooling device again, closed circulation of the DC waste gas is achieved, no tail gas is discharged, and the problem of environmental pollution is effectively solved. And the first waste heat recovery unit regenerates hot air by utilizing the waste heat of the DC waste gas, and the second waste heat recovery unit generates new steam required by desolventizing baking by utilizing the waste heat of the DC waste gas, so that the efficient recycling of the waste heat of the DC waste gas is realized, the consumption of the live steam is reduced, and the waste of resources is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of grain and oil processing, and particularly relates to a drying and cooling waste heat recovery system and a grain and oil processing production line. Background Art

[0002] In the field of grain and oil processing, after oilseeds are infiltrated with organic solvents such as n-hexane into wet soybean meal in the leaching workshop, they are subjected to desolventization roasting (Desolventazationer Toaster, abbreviated as DT) treatment in the stripping workshop. Under the heating action of high-temperature steam, the organic solvent and the dissolved oil are carried away by the steam, and the remaining high-temperature wet soybean meal needs to be subjected to dry cooling (Dry Cooling, abbreviated as DC) treatment.

[0003] The dry cooling (DC) exhaust gas generated after dry cooling treatment has a high temperature, high humidity, and a large amount of waste heat. At present, usually, the DC exhaust gas is used to preheat fresh air, and then the DC exhaust gas is discharged.

[0004] However, in this way, the waste heat utilization rate of the DC exhaust gas is extremely low, less than 10% of the waste heat, resulting in a huge waste of waste heat. At the same time, the discharged DC exhaust gas contains some volatile organic compounds (Volatile Organic Compounds, abbreviated as VOCs) gas, which will cause environmental pollution problems.

[0005] Therefore, how to solve the problems of low waste heat utilization rate of the dry cooling exhaust gas generated in grain and oil processing in the prior art, resulting in waste of waste heat, and environmental pollution has become an important technical problem to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a drying and cooling waste heat recovery system and a grain and oil processing production line to solve the problems of low waste heat utilization rate of the dry cooling exhaust gas generated in grain and oil processing in the prior art, resulting in waste of waste heat, and environmental pollution.

[0007] To achieve the above purpose, the present invention provides a drying and cooling waste heat recovery system, including a hot air circulation unit, a first waste heat recovery unit, and a second waste heat recovery unit.

[0008] The hot air circulation unit includes a hot air power device, a drying and cooling device, and a dust removal device that are arranged in sequence and connected end to end to form a hot air circulation loop. Among them, the hot air power device is used to introduce hot air into the drying and cooling device.

[0009] The drying and cooling device is used to dry and cool the high-temperature wet soybean meal with the hot air and discharge the hot air as dry cooling exhaust gas.

[0010] The dust removal device is used to purify the dry cooling exhaust gas.

[0011] The first waste heat recovery unit is arranged between the dust removal device and the hot air power device, and the first waste heat recovery unit is provided with a connected waste gas outlet and a waste gas inlet. The second waste heat recovery unit is arranged between the waste gas outlet and the waste gas inlet.

[0012] The first waste heat recovery unit and the second waste heat recovery unit are used to recover and utilize the waste heat of the drying and cooling waste gas step by step. Among them, the first waste heat recovery unit is used to recover and utilize the waste heat of the drying and cooling waste gas through the first circulating working medium to generate the hot air, and the second waste heat recovery unit is used to recover and utilize the waste heat of the drying and cooling waste gas to generate new steam.

[0013] According to the drying and cooling waste heat recovery system provided by the present invention, the first waste heat recovery unit includes a heat exchanger, a working medium circulation pump, and a preheater that are arranged in sequence and connected end to end to form a first working medium circulation loop.

[0014] The working medium circulation pump is used to provide power for the flow of the first circulating working medium.

[0015] The heat exchanger is used to exchange heat with the purified drying and cooling waste gas. The heat exchanger includes a first heat exchange path and a second heat exchange path that exchange heat with each other. The two ends of the first heat exchange path are respectively connected to the dust removal device and the waste gas outlet, and the two ends of the second heat exchange path are respectively connected to the preheater and the working medium circulation pump.

[0016] The preheater is used to reheat the drying and cooling waste gas after passing through the second waste heat recovery unit to generate the hot air. The preheater includes a third heat exchange path and a fourth heat exchange path that exchange heat with each other. The two ends of the third heat exchange path are respectively connected to the waste gas inlet and the hot air power device, and the two ends of the fourth heat exchange path are respectively connected to the working medium circulation pump and the heat exchanger.

[0017] According to the drying and cooling waste heat recovery system provided by the present invention, the second waste heat recovery unit includes:

[0018] A waste heat recovery device, including a waste heat recovery heat exchanger, a compressor, a waste heat release heat exchanger, and valve parts that are arranged in sequence and connected end to end to form a waste heat recovery circulation loop. Among them, the waste heat recovery heat exchanger includes a fifth heat exchange path and a sixth heat exchange path that exchange heat with each other. The two ends of the fifth heat exchange path are respectively connected to the waste gas outlet and the waste gas inlet, and the two ends of the sixth heat exchange path are respectively connected to the valve parts and the compressor;

[0019] A new steam generation device, comprising a steam generator and a second working medium circulation loop, wherein the second working medium circulation loop is used for the flow of a second circulating working medium, the steam generator is arranged in the second working medium circulation loop, the steam generator is used for recovering and utilizing the waste heat of the drying and cooling waste gas through the second circulating working medium to generate the new steam, and the waste heat release heat exchanger comprises a seventh heat exchange passage and an eighth heat exchange passage that exchange heat with each other, two ends of the seventh heat exchange passage are respectively connected to the compressor and the valve member, and the eighth heat exchange passage is arranged in the second working medium circulation loop.

[0020] According to the drying and cooling waste heat recovery system provided by the present invention, the new steam generation device further comprises:

[0021] A water supply pipeline, one end of which is connected to the water inlet of the steam generator and the other end is used for connecting to an external water source;

[0022] A steam delivery pipeline, which is connected to the steam outlet of the steam generator, and the steam delivery pipeline is used for outputting the new steam.

[0023] According to the drying and cooling waste heat recovery system provided by the present invention, it further comprises:

[0024] A desolventizing and baking device, which is connected to the drying and cooling device, the desolventizing and baking device is provided with a new steam inlet, the new steam inlet is connected to the steam delivery pipeline, and the desolventizing and baking device is used for using the new steam to perform desolventizing and baking treatment on wet soybean meal and generating the high-temperature wet soybean meal.

[0025] According to the drying and cooling waste heat recovery system provided by the present invention, the drying and cooling device is provided with a soybean meal outlet, and the soybean meal outlet is used for connecting to a soybean meal collection device.

[0026] According to the drying and cooling waste heat recovery system provided by the present invention, the dust removal device is configured as a DC cyclone, and the DC cyclone is provided with a soybean meal powder outlet, and the soybean meal powder outlet is used for connecting to a soybean meal collection device.

[0027] According to the drying and cooling waste heat recovery system provided by the present invention, the heat exchanger is configured as a spray heat exchanger.

[0028] According to the drying and cooling waste heat recovery system provided by the present invention, the desolventizing and baking device comprises:

[0029] A wet meal inlet channel, which is used for supplying the wet soybean meal;

[0030] A steam output channel, which is used for outputting the steam carrying grease.

[0031] The present invention also provides a grain and oil processing production line, comprising the drying and cooling waste heat recovery system as described in any one of the above.

[0032] The dry cooling waste heat recovery system provided by the present invention includes a hot air circulation unit, a first waste heat recovery unit, and a second waste heat recovery unit. The hot air circulation unit includes a hot air power device, a dry cooling device, and a dust removal device that are arranged in sequence and connected end to end to form a hot air circulation loop. Among them, the hot air power device is used to introduce hot air into the dry cooling device, the dry cooling device is used to dry and cool high-temperature wet soybean meal with hot air, and discharge the hot air as dry cooling waste gas, and the dust removal device is used to purify the dry cooling waste gas. The first waste heat recovery unit is arranged between the dust removal device and the hot air power device, and the first waste heat recovery unit is provided with a connected waste gas outlet and a waste gas inlet. The second waste heat recovery unit is arranged between the waste gas outlet and the waste gas inlet. The first waste heat recovery unit and the second waste heat recovery unit are used to recover and utilize the waste heat of the dry cooling waste gas step by step. Among them, the first waste heat recovery unit is used to recover and utilize the waste heat of the dry cooling waste gas through a first circulating working medium to generate hot air, and the second waste heat recovery unit is used to recover and utilize the waste heat of the dry cooling waste gas to generate new steam.

[0033] With such a setting, after the DC waste gas leaves the dry cooling device, it passes through the dust removal device, the first waste heat recovery unit, the second waste heat recovery unit, and the hot air power device, and then is sent back to the dry cooling device again, thus realizing the closed-loop circulation of the DC waste gas and no tail gas emission, effectively solving the environmental pollution problem. At the same time, through the first waste heat recovery unit, the waste heat of the DC waste gas can be utilized to regenerate hot air subsequently. Through the second waste heat recovery unit, the waste heat of the DC waste gas can be utilized to generate new steam required for desolventization and baking, thus realizing the efficient recovery and utilization of the waste heat of the DC waste gas, reducing the consumption of live steam, avoiding waste of resources, reducing the system energy consumption, and lowering the system operation cost. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 is a schematic structural diagram of the dry cooling waste heat recovery system provided by the present invention;

[0036] Figure 2 is a schematic structural diagram of the first waste heat recovery unit provided by the present invention;

[0037] Figure 3 is a schematic structural diagram of the second waste heat recovery unit provided by the present invention;

[0038] Reference Signs:

[0039] 1: Desorption baking device; 2: Drying and cooling device; 3: Hot air power device; 4: Preheater; 5: Second waste heat recovery unit; 501: Waste heat recovery heat exchanger; 502: Compressor; 503: Waste heat release heat exchanger; 504: Steam generator; 505: Water supply pipeline; 506: Valve; 6: Heat exchanger; 7: Working medium circulation pump; 8: DC cyclone; 9: Wet meal inlet channel; 10: Steam transmission pipeline; 11: Soybean meal powder outlet; 12: Low-temperature cold air outlet; 13: Spray exhaust gas outlet; 14: Spray exhaust gas inlet; 15: Steam output channel; 16: DC exhaust gas outlet; 17: Soybean meal outlet; 18: First waste heat recovery unit; 19: Exhaust gas outlet; 20: Exhaust gas inlet. Detailed implementation manners

[0040] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0041] The following Figures 1 to 3 describes the drying, cooling and waste heat recovery system of the present invention.

[0042] As Figures 1 to 3 shown, the embodiment of the present invention provides a drying, cooling and waste heat recovery system, including a hot air circulation unit, a first waste heat recovery unit 18 and a second waste heat recovery unit 5. Specifically, as Figure 1 shown, the hot air circulation unit includes a hot air power device 3, a drying and cooling device 2 and a dust removal device which are arranged in sequence and connected end to end to form a hot air circulation loop. Among them, the hot air power device 3 is used to introduce hot air into the drying and cooling device 2. Specifically, for example, it is a blower, and the blower is connected to the drying and cooling device 2 through a pipeline, so as to provide power for the hot air circulation and send the hot air into the drying and cooling device 2. The drying and cooling device 2 is used to dry and cool the high-temperature wet soybean meal by using hot air, and after the hot air takes away heat and moisture, it becomes dry and cooling exhaust gas and is discharged from the DC exhaust gas outlet 16. The drying and cooling device 2 is a mature existing product, so its specific structure and the like will not be described in detail here. The dust removal device is connected to the DC exhaust gas outlet 16 through a pipeline and is used to purify the drying and cooling (DC) exhaust gas and remove impurities such as dust in the DC exhaust gas.

[0043] The first waste heat recovery unit 18 is arranged between the dust removal device and the hot air power device 3, and the first waste heat recovery unit 18 is provided with a connected exhaust gas outlet 19 and an exhaust gas inlet 20. The second waste heat recovery unit 5 is arranged between the exhaust gas outlet 19 and the exhaust gas inlet 20. The first waste heat recovery unit 18 and the second waste heat recovery unit 5 are used to recover and utilize the DC waste gas heat step by step. Among them, the first waste heat recovery unit 18 is used to recover and utilize the DC waste gas heat through the first circulating working medium to generate hot air. For example, the first circulating working medium is water. The second waste heat recovery unit 5 is used to recover and utilize the DC waste gas heat to generate new steam.

[0044] In this way, as Figure 1 shown, after the DC waste gas leaves the drying and cooling device 2, it is dust-removed by the dust removal device, and after heat exchange and cooling in the first waste heat recovery unit 18, it enters the second waste heat recovery unit 5 again for heat exchange. At this time, the temperature and humidity of the DC waste gas discharged from the second waste heat recovery unit 5 drop to the ambient air level and can be used as a drying medium again. Then, after being reheated by the heat absorbed by the first waste heat recovery unit 18, it enters the hot air power device 3 and returns to the drying and cooling device 2 again. At the same time, the second waste heat recovery unit 5 uses the absorbed heat to produce the new steam required for desolventization and baking.

[0045] With such a setting, after the DC waste gas leaves the drying and cooling device 2, it passes through the dust removal device, the first waste heat recovery unit 18, the second waste heat recovery unit 5 and the hot air power device 3, and then is sent back to the drying and cooling device 2 again, thus realizing the closed-loop cycle of the DC waste gas and no tail gas emission, effectively solving the environmental pollution problem. At the same time, through the first waste heat recovery unit 18, the DC waste gas heat can be utilized to regenerate hot air subsequently. Through the second waste heat recovery unit, the DC waste gas heat can be utilized to generate the new steam required for desolventization and baking, thus realizing the efficient recovery and utilization of the DC waste gas heat, reducing the consumption of live steam, avoiding waste of resources, reducing the system energy consumption and lowering the system operation cost. It should be noted that Figure 1 the direction indicated by the arrow in

[0046] In the embodiment of the present invention, the first waste heat recovery unit 18 includes a heat exchanger 6, a working medium circulation pump 7 and a preheater 4 which are arranged in sequence and connected end to end to form a first working medium circulation loop. Specifically, as Figure 2As shown, the working fluid circulation pump 7 is used to provide power for the flow of the first circulating working fluid. The heat exchanger 6 is used to exchange heat with the purified dry cooling exhaust gas to recover the waste heat of the exhaust gas. The heat exchanger 6 includes a first heat exchange path and a second heat exchange path that exchange heat with each other. The two ends of the first heat exchange path are respectively connected to the dust removal device and the exhaust gas outlet 19 through pipelines, and the two ends of the second heat exchange path are respectively connected to the preheater 4 and the working fluid circulation pump 7 through pipelines. Thus, the first circulating working fluid can absorb the waste heat of the DC exhaust gas at the heat exchanger 6 and carry the heat to flow to the preheater 4. The dry cooling exhaust gas enters the second waste heat recovery unit 5 after being cooled by the heat exchanger 6 for further heat exchange and cooling, and is reduced to the ambient air level, and can be reused as a drying medium. In addition, in the heat exchanger 6, the flow direction of the DC exhaust gas is opposite to the flow direction of the first circulating working fluid to form a countercurrent convection to improve the heat exchange effect.

[0047] The preheater 4 is used to reheat the dry cooling exhaust gas after passing through the second waste heat recovery unit 5 to generate hot air and return it to the dry cooling device 2. The preheater 4 includes a third heat exchange path and a fourth heat exchange path that exchange heat with each other. The two ends of the third heat exchange path are respectively connected to the exhaust gas inlet 20 and the hot air power device 3 through pipelines, and the two ends of the fourth heat exchange path are respectively connected to the working fluid circulation pump 7 and the heat exchanger 6 through pipelines. Thus, the preheater 4 uses the waste heat of the exhaust gas carried by the first circulating working fluid to reheat the DC exhaust gas to generate fresh air and send it back to the dry cooling device 2 again to complete the closed-loop cycle of the DC exhaust gas. In addition, in the preheater 4, the flow direction of the DC exhaust gas is opposite to the flow direction of the first circulating working fluid to form a countercurrent convection to improve the heat exchange effect.

[0048] With such a setting, by recovering and utilizing part of the waste heat of the DC exhaust gas through the first waste heat recovery unit 18, it can be used to reheat the exhaust gas to generate fresh air, reduce the system energy consumption, and improve the utilization rate of the waste heat of the exhaust gas. It should be noted that Figure 2 the direction indicated by the arrow in the figure represents the fluid flow direction.

[0049] In a specific embodiment of the present invention, the second waste heat recovery unit 5 includes a waste heat recovery device and a new steam generation device. As Figure 3As shown in the figure, the waste heat recovery device includes a waste heat recovery heat exchanger 501, a compressor 502, a waste heat release heat exchanger 503, and a valve member 506 that are arranged in sequence and connected end to end to form a waste heat recovery circulation loop. Among them, the waste heat recovery heat exchanger 501 includes a fifth heat exchange passage and a sixth heat exchange passage that exchange heat with each other. The two ends of the fifth heat exchange passage are respectively connected to the exhaust gas outlet 19 and the exhaust gas inlet 20 through pipelines, and the two ends of the sixth heat exchange passage are respectively connected to the valve member 506 and the compressor 502 through pipelines. Among them, the valve member 506 is used to throttle the heat transfer medium. Specifically, a commonly used throttle valve or the like in the prior art can be selected. Thus, the heat transfer medium can further absorb the remaining heat of the DC exhaust gas at the waste heat recovery heat exchanger 501, and the DC exhaust gas forms low-temperature cold air and flows out from the low-temperature cold air outlet 12 and enters the exhaust gas inlet 20 to be reheated at the preheater 4 to form fresh air. In addition, in the waste heat recovery heat exchanger 501, the flow direction of the DC exhaust gas is opposite to the flow direction of the heat transfer medium to form countercurrent convection, improving the heat exchange effect.

[0050] The new steam generation device includes a steam generator 504 and a second working medium circulation loop. Among them, the second working medium circulation loop is used for the second circulating working medium to flow. For example, the second circulating working medium is water. The steam generator 504 is arranged in the second working medium circulation loop, and the steam generator 504 is used to recover and utilize the waste heat of the dry cooling exhaust gas through the second circulating working medium to generate new steam.

[0051] Among them, the waste heat release heat exchanger 503 includes a seventh heat exchange passage and an eighth heat exchange passage that exchange heat with each other. The two ends of the seventh heat exchange passage are respectively connected to the compressor 502 and the valve member 506 through pipelines, and the eighth heat exchange passage is arranged in the second working medium circulation loop. Specifically, the eighth heat exchange passage is connected to both ends of the steam generator 504 through a pipeline. Thus, in the waste heat release heat exchanger 503, the heat transfer medium transfers the absorbed DC waste heat to the second circulating working medium, and then the steam generator 504 can use the heat absorbed by the second circulating working medium to produce new steam, enabling the effective utilization of DC waste heat. In addition, in the waste heat release heat exchanger 503, the flow direction of the heat transfer medium is opposite to the flow direction of the second circulating working medium to form countercurrent convection, improving the heat exchange efficiency. It should be noted that Figure 3 the direction indicated by the arrow in the figure represents the fluid flow direction.

[0052] With such a setting, in the second waste heat recovery unit 5, the DC waste gas exchanges heat in the waste heat recovery heat exchanger 501 and becomes low-temperature cold air, which is sent out of the second waste heat recovery unit 5 through the low-temperature cold air outlet 12. After the heat exchange working medium absorbs the waste heat of the waste gas and evaporates in the waste heat recovery heat exchanger 501, it is pressurized and heated by the compressor 502, and then exchanges heat with the second circulating working medium in the waste heat release heat exchanger 503. Subsequently, the heat exchange working medium returns to the waste heat recovery heat exchanger 501 after throttling through the valve 506 for the next cycle. At the same time, after absorbing heat in the waste heat release heat exchanger 503, the second circulating working medium enters the steam generator 504 to produce new steam. Thus, after the second waste heat recovery unit 5 recovers the remaining heat of the DC waste gas by using the waste heat recovery device, it uses the steam generator 504 to produce the new steam required in the grain and oil processing process, greatly reducing the energy consumption of the system and reducing the consumption of live steam.

[0053] In an alternative embodiment of the present invention, the new steam generating device further includes a water supply pipeline 505. As Figure 3 shown, one end of the water supply pipeline 505 is connected to the water inlet of the steam generator 504, and the other end is used to connect to an external water source, so that the waste heat of the waste gas can be used for heating to form new steam for grain and oil processing.

[0054] Furthermore, the new steam generating device further includes a steam delivery pipeline 10. The steam delivery pipeline 10 is connected to the steam outlet of the steam generator 504. The steam delivery pipeline 10 is used to output new steam, so as to facilitate connecting to other devices and supplying new steam.

[0055] As an alternative embodiment of the present invention, the drying and cooling waste heat recovery system further includes a desolventizing and baking device 1. The desolventizing and baking device 1 is connected to the drying and cooling device 2. Specifically, as Figure 1 shown, the upper part of the drying and cooling device 2 is connected to the desolventizing and baking device 1. Among them, the desolventizing and baking device 1 is an existing mature product, so its specific structure and the like will not be described in detail here. The desolventizing and baking device 1 is provided with a new steam inlet, and the new steam inlet is connected to the steam delivery pipeline 10. The desolventizing and baking device 1 is used to perform desolventizing and baking treatment on wet soybean meal with new steam and generate high-temperature wet soybean meal. With such a setting, the desolventizing and baking device 1 can use the new steam produced by the second waste heat recovery unit 5 to perform desolventizing and baking treatment on wet meal, thereby reducing the energy consumption of the system and making full use of the waste heat of the DC waste gas.

[0056] In a specific embodiment of the present invention, the desolventizing and baking device 1 includes a wet meal inlet channel 9 and a steam output channel 15. The wet meal inlet channel 9 is used to supply wet soybean meal. Specifically, as Figure 1As shown in the figure, a wet meal inlet channel 9 is provided at the upper part of the desolventizing and toasting device 1, through which wet soybean meal can be added to the desolventizing and toasting device 1. The steam output channel 15 is used to output the steam carrying grease. In this way, the high-temperature steam takes away the organic solvent and the dissolved oil, and is sent out from the steam output channel 15 and enters the subsequent technological processes, such as grease separation, DT waste heat utilization, etc. It should be noted that, taking the placement position of the drying and cooling waste heat recovery system as shown in Figure 1 the figure, the up and down directions in the figure are the indicated up and down orientations.

[0057] In the embodiment of the present invention, the drying and cooling device 2 is provided with a soybean meal outlet 17. Specifically, the soybean meal outlet 17 is arranged at the lower part of the drying and cooling device 2. The soybean meal outlet 17 is used to connect to a soybean meal collection device, so as to facilitate the collection and storage of soybean meal. The soybean meal can be used as an animal feed ingredient, etc., to increase the system income.

[0058] In an alternative embodiment of the present invention, the dust removal device is configured as a DC cyclone 8. The DC cyclone 8 is provided with a soybean meal powder outlet 11, and the soybean meal powder outlet 11 is used to connect to a soybean meal collection device. In this way, the DC cyclone 8 can further remove the soybean meal dust carried by the DC waste gas and concentrate it to be output from the soybean meal powder outlet 11, so as to achieve zero dust emission and avoid environmental problems.

[0059] As an alternative embodiment of the present invention, the heat exchanger 6 is configured as a spray heat exchanger. The spray heat exchanger has a simple structure, convenient operation, high heat transfer efficiency, is easy to be anti-corrosive, and has a long service life. Specifically, the spray heat exchanger is provided with a spray waste gas inlet 14 and a spray waste gas outlet 13. The upper gas outlet of the DC cyclone 8 is connected to the spray waste gas inlet 14 through a pipeline. The spray waste gas outlet 13 is the waste gas outlet 19 of the first waste heat recovery unit 18, and it is connected to the fifth heat exchange path of the waste heat recovery heat exchanger 501 through a pipeline.

[0060] In summary, the embodiment of the present invention provides a drying and cooling waste heat recovery system, which is applicable to the heat recovery and utilization process of drying and cooling after soybean meal stripping, including a desolventizing and baking device 1, a drying and cooling device 2, a dust removal device, a first waste heat recovery unit 18, a second waste heat recovery unit 5, a hot air power device 3, etc. Specifically, during operation, wet soybean meal enters the desolventizing and baking device 1 from the wet meal inlet channel 9, and after being heated by hot steam to extract the mixture of n-hexane and oil, it enters the drying and cooling device 2. The blower sends hot air into the drying and cooling device 2 to dry and cool the wet soybean meal. Subsequently, the DC waste gas with a relatively high moisture content enters the DC cyclone 8 through the DC waste gas outlet 16. After dust removal in the DC cyclone 8, the waste gas leaves from the upper part and enters the spray heat exchanger. In the spray heat exchanger, the waste gas exchanges heat and is cooled with water. The heat-exchanged water is sent to the preheater 4 by the working fluid circulation pump 7, and the cooled waste gas is sent to the second waste heat recovery unit 5 to completely recover the remaining heat. The low-temperature cold air sent out from the second waste heat recovery unit 5 enters the preheater 4 through the low-temperature cold air outlet 12. In the preheater 4, the heat-exchanged water transfers heat to the low-temperature cold air, and the preheated low-temperature cold air is sent back to the drying and cooling device 2 by the blower to complete the DC waste gas cycle.

[0061] Meanwhile, in the second waste heat recovery unit 5, the DC waste gas exchanges heat with the heat transfer working fluid through the waste heat recovery heat exchanger 501 and becomes low-temperature cold air and then leaves the second waste heat recovery unit 5. After absorbing the waste heat of the DC waste gas and evaporating, the heat transfer working fluid is boosted in pressure and temperature by the compressor 502, exchanges heat with the second circulating working fluid in the waste heat release heat exchanger 503, and then the heat transfer working fluid returns to the waste heat recovery heat exchanger 501 through throttling for the next cycle. The second circulating working fluid heated in the waste heat release heat exchanger 503 enters the steam generator 503 to produce new steam, and then the new steam is sent to the desolventizing and baking device 1 for desolventizing and baking treatment of the wet soybean meal.

[0062] With such a setting, it has a simple structure, excellent benefits, reasonable layout, and ingenious design. It can realize the closed-loop circulation of DC waste gas, achieve the purposes of highly efficient recovery and utilization of waste heat in the drying and cooling process and zero emission of waste gas dust, and reduce the consumption of live steam in the grain and oil processing process.

[0063] Next, the grain and oil processing production line provided by the present invention will be described. The grain and oil processing production line described below can be mutually corresponding and referred to with the drying and cooling waste heat recovery system described above.

[0064] The embodiment of the present invention also provides an oil and grain processing production line, including the drying and cooling waste heat recovery system in each of the above embodiments. With such a setting, after the DC waste gas leaves the drying and cooling device 2, it passes through the dust removal device, the first waste heat recovery unit 18, the second waste heat recovery unit 5 and the hot air power device 3, and then is sent back to the drying and cooling device 2 again, thereby realizing the closed-loop circulation of the DC waste gas and no tail gas emission, effectively solving the environmental pollution problem. At the same time, through the first waste heat recovery unit 18, the waste heat of the DC waste gas can be utilized to regenerate hot air subsequently, and through the second waste heat recovery unit, the waste heat of the DC waste gas can be utilized to generate new steam required for desolventizing and baking, thereby realizing the efficient recovery and utilization of the waste heat of the DC waste gas, reducing the consumption of live steam, avoiding waste of resources, reducing the system energy consumption and lowering the system operation cost. The derivation process of this beneficial effect is roughly similar to the derivation process of the beneficial effect of the above drying and cooling waste heat recovery system, so it will not be elaborated here.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A drying and cooling waste heat recovery system, characterized in that, it includes a hot air circulation unit, a first waste heat recovery unit (18) and a second waste heat recovery unit (5), the hot air circulation unit includes a hot air power device (3), a drying and cooling device (2) and a dust removal device which are arranged in sequence and connected end to end to form a hot air circulation loop, wherein the hot air power device (3) is used to introduce hot air into the drying and cooling device (2), the drying and cooling device (2) is used to dry and cool the high-temperature wet soybean meal with the hot air and discharge the hot air as drying and cooling waste gas, the dust removal device is used to purify the drying and cooling waste gas, the first waste heat recovery unit (18) is arranged between the dust removal device and the hot air power device (3), and the first waste heat recovery unit (18) is provided with a connected waste gas outlet (19) and a waste gas inlet (20), and the second waste heat recovery unit (5) is arranged between the waste gas outlet (19) and the waste gas inlet (20), the first waste heat recovery unit (18) and the second waste heat recovery unit (5) are used to recover and utilize the waste heat of the drying and cooling waste gas step by step, wherein the first waste heat recovery unit (18) is used to recover and utilize the waste heat of the drying and cooling waste gas through a first circulating working medium to generate the hot air, and the second waste heat recovery unit (5) is used to recover and utilize the waste heat of the drying and cooling waste gas to generate new steam.

2. The drying and cooling waste heat recovery system according to claim 1, characterized in that, the first waste heat recovery unit (18) includes a heat exchanger (6), a working medium circulation pump (7) and a preheater (4) which are arranged in sequence and connected end to end to form a first working medium circulation loop, the working medium circulation pump (7) is used to provide power for the flow of the first circulating working medium, the heat exchanger (6) is used to exchange heat with the purified drying and cooling waste gas, the heat exchanger (6) includes a first heat exchange path and a second heat exchange path for exchanging heat with each other, the two ends of the first heat exchange path are respectively connected to the dust removal device and the waste gas outlet (19), and the two ends of the second heat exchange path are respectively connected to the preheater (4) and the working medium circulation pump (7), the preheater (4) is used to reheat the drying and cooling waste gas after passing through the second waste heat recovery unit (5) to generate the hot air, the preheater (4) includes a third heat exchange path and a fourth heat exchange path for exchanging heat with each other, the two ends of the third heat exchange path are respectively connected to the waste gas inlet (20) and the hot air power device (3), and the two ends of the fourth heat exchange path are respectively connected to the working medium circulation pump (7) and the heat exchanger (6).

3. The drying and cooling waste heat recovery system according to claim 1, characterized in that, the second waste heat recovery unit (5) includes: The waste heat recovery device includes a waste heat recovery heat exchanger (501), a compressor (502), a waste heat release heat exchanger (503), and a valve member (506) that are arranged in sequence and connected end to end to form a waste heat recovery circulation loop. Among them, the waste heat recovery heat exchanger (501) includes a fifth heat exchange path and a sixth heat exchange path that exchange heat with each other. The two ends of the fifth heat exchange path are respectively connected to the exhaust gas outlet (19) and the exhaust gas inlet (20), and the two ends of the sixth heat exchange path are respectively connected to the valve member (506) and the compressor (502); The new steam generation device includes a steam generator (504) and a second working fluid circulation loop. Among them, the second working fluid circulation loop is used for the second circulating working fluid to flow. The steam generator (504) is arranged in the second working fluid circulation loop. The steam generator (504) is used to recover and utilize the waste heat of the dry cooling exhaust gas through the second circulating working fluid to generate the new steam. And the waste heat release heat exchanger (503) includes a seventh heat exchange path and an eighth heat exchange path that exchange heat with each other. The two ends of the seventh heat exchange path are respectively connected to the compressor (502) and the valve member (506), and the eighth heat exchange path is arranged in the second working fluid circulation loop.

4. The dry cooling waste heat recovery system according to claim 3, characterized in that, The new steam generation device further includes: A water supply pipeline (505) whose one end is connected to the water inlet of the steam generator (504) and the other end is used to connect to an external water source; A steam delivery pipeline (10) is connected to the steam outlet of the steam generator (504), and the steam delivery pipeline (10) is used to output the new steam.

5. The dry cooling waste heat recovery system according to claim 4, characterized in that, It further includes: A desolventizing and baking device (1) is connected to the dry cooling device (2). The desolventizing and baking device (1) is provided with a new steam inlet, and the new steam inlet is connected to the steam delivery pipeline (10). The desolventizing and baking device (1) is used to perform desolventizing and baking treatment on wet soybean meal with the new steam and generate the high-temperature wet soybean meal.

6. The dry cooling waste heat recovery system according to claim 1, characterized in that, The dry cooling device (2) is provided with a soybean meal outlet (17), and the soybean meal outlet (17) is used to connect to a soybean meal collection device.

7. The dry cooling waste heat recovery system according to claim 1, characterized in that, The dust removal device is configured as a DC cyclone (8). The DC cyclone (8) is provided with a soybean meal powder outlet (11), and the soybean meal powder outlet (11) is used to connect to a soybean meal collection device.

8. The dry cooling waste heat recovery system according to claim 2, characterized in that, The heat exchanger (6) is configured as a spray heat exchanger.

9. The dry cooling waste heat recovery system according to claim 5, characterized in that, The desolventizing and baking device (1) includes: A wet meal inlet channel (9) for supplying the wet soybean meal; A steam output channel (15) for outputting steam carrying grease.

10. A grain and oil processing production line, characterized in that it includes the drying and cooling waste heat recovery system according to any one of claims 1-9.

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