Oil and fat extraction plant waste heat recovery system

Abstract

The utility model belongs to the technical field of waste heat recovery. Oil grease leaching workshop waste heat recovery system, include: steam -off drying machine, including steam -off mechanism and drying mechanism, be provided with pre -drying layer on drying mechanism, be provided with air inlet, air outlet on pre -drying layer, be provided with dust removal equipment on air outlet, falling film evaporator, via induced draft fan and dust removal device are connected, a plurality of series connection set first waste heat recovery ware, be used for the heat exchange of circulating water, and first waste heat recovery ware is connected with the hot air export that falling film evaporator is provided with, second waste heat recovery ware, be used for the heat exchange of cold air, second waste heat recovery ware is connected with tail first waste heat recovery ware, and cold air is introduced into the air inlet of pre -drying layer by fan after the heat exchange of second waste heat recovery ware. The utility model is used to solve the technical problem of steam consumption of existing steam -off drying machine, and solvent recovery is not sufficient.

Description

Technical Field

[0001] This utility model belongs to the field of waste heat recovery technology, specifically relating to a waste heat recovery system for an oil leaching workshop. Background Technology

[0002] In the industrial production and processing of oilseeds, leaching technology is commonly used. This involves the hexane extraction method, where bulk oilseeds are pre-treated and then transported to the leaching workshop for full contact with hexane.

[0003] By employing processes such as spraying, soaking, permeation, and draining, the oil in the oilseeds is dissolved, thus separating the oil from the dry material.

[0004] The extracted material separates into two phases: a mixed oil and a wet meal. To obtain both the oil and meal while simultaneously recovering the extractant hexane, the mixed oil and wet meal need to be processed separately.

[0005] For mixed oils, multi-effect evaporation and stripping processes are used to remove n-hexane from the mixed oil to obtain crude oil. For wet meal, a vertical steam desiccant dryer is used to remove n-hexane from the material. The removed n-hexane is then condensed, recovered, and reused. After desolventizing and drying, the meal enters the meal processing workshop for screening, crushing, and packaging.

[0006] Existing vertical steam desiccant dryers do not fully utilize the residual heat from hot meal and do not effectively recover residual solvents. This results in high steam consumption in the steam desiccant and insufficient solvent recovery, leading to high concentrations of exhaust gas and significant environmental pollution.

[0007] Furthermore, the non-condensable exhaust gas generated throughout the workshop contains a large amount of n-hexane, which is currently mostly absorbed by paraffin oil. Paraffin oil has poor adsorption effect on low-concentration exhaust gas, resulting in high emission concentrations, typically reaching 20,000 to 30,000 mg / L. These emission concentrations significantly exceed existing emission standards in various regions, leading companies to primarily use dilution methods. This is strictly prohibited under air pollution control laws and results in substantial solvent waste. Among existing end-of-pipe treatment technologies, activated carbon is prone to saturation, generating large amounts of hazardous waste during daily operation and incurring extremely high operating costs; incineration poses significant safety risks and lacks sufficient solvent recovery, leading to low economic efficiency; plasma treatment is greatly affected by moisture and has low technical efficiency. Given that paraffin oil adsorption is ineffective for treating low-concentration exhaust gas and requires low-temperature adsorption followed by high-temperature desorption, resulting in high steam consumption during operation, this approach is not feasible. Utility Model Content

[0008] The purpose of this invention is to provide a waste heat recovery system for oil extraction workshops to solve the technical problems of high steam consumption and insufficient solvent recovery in existing descaling dryers.

[0009] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a waste heat recovery system for oil leaching workshops, characterized in that it includes:

[0010] An evaporation dryer includes an evaporation mechanism and a drying mechanism. A pre-drying layer is provided on the drying mechanism. An air inlet and an air outlet are provided on the pre-drying layer. A dust removal device is provided on the air outlet.

[0011] The falling film evaporator is connected to a dust removal device via an induced draft fan;

[0012] Several first waste heat recovery units are connected in series for heat exchange of circulating water, and the first first waste heat recovery unit is connected to the hot air outlet provided on the falling film evaporator.

[0013] The second waste heat recovery unit is used for heat exchange of cold air. The second waste heat recovery unit is connected to the first waste heat recovery unit at the tail. After the cold air is heat exchanged by the second waste heat recovery unit, it is introduced into the air inlet of the pre-drying layer by the fan.

[0014] This invention utilizes a high-temperature exhaust gas containing a large amount of water vapor, typically reaching 95°C, and also contains hexane. The hot air undergoes multi-stage heat recovery using a falling film evaporator, several first waste heat recovery units connected in series, and a second waste heat recovery unit at the end, ensuring thorough heat recovery. Even after heat recovery, the exhaust gas still contains a significant amount of hexane and is directly discharged. This invention employs a falling film internal circulation evaporator, resulting in a more stable evaporation temperature.

[0015] The hot air temperature after heat exchange is 40-50℃, and this hot air contains approximately 2000 mg / L n-hexane. Direct emission of this hot air pollutes the environment and wastes resources. To solve the above technical problems, this utility model adopts the following technical solution: the waste heat recovery system in the oil leaching workshop further includes a primary alkali spraying mechanism, comprising:

[0016] The first alkali spray tower is equipped with an air inlet 1, an air inlet 2, an alkali liquid inlet 1, an air outlet 1, and a condensate outlet 1; the air inlet 1 is used to introduce hot air after heat exchange by the second waste heat recovery unit, and the air inlet 2 is used to introduce exhaust gas from the oil leaching workshop.

[0017] A water cooler is connected to the first alkali spray tower via a first circulating pump; the water cooler is provided with a circulating water inlet and a circulating water outlet; the water cooler is provided with a liquid outlet pipe, the end of which is located inside the first alkali spray tower for spraying alkali solution.

[0018] This invention employs an alkaline washing and low-temperature water cooling method to thoroughly remove impurities such as meal powder, oil droplets, and free fatty acids from the exhaust gas. Circulating cooling water is used to cool the alkaline spray solution. The cooled spray solution directly contacts the exhaust gas, carrying away heat.

[0019] To further solve the above-mentioned technical problems, the present invention adopts the following technical solution: the waste heat recovery system in the oil leaching workshop further includes a secondary alkali spraying mechanism, comprising:

[0020] The second alkali spray tower is equipped with an air inlet three, an alkali liquid inlet two, a condensate outlet two, and an air outlet two; the air inlet three and the air outlet one are connected by a pipeline.

[0021] A low-temperature water cooler is connected to the second alkali spray tower via a second circulating pump; the low-temperature water cooler is provided with a second chilled water inlet and a second chilled water outlet; the low-temperature water cooler is provided with a second liquid outlet pipe, the end of which is located inside the second alkali spray tower for spraying alkali solution;

[0022] The surface cooler is provided with a chilled water inlet 1, a chilled water outlet 1, a condensate outlet, an air inlet 4, and an air outlet 3. The chilled water outlet is connected to the chilled water inlet 2 of the low-temperature water cooler via a pipe, and the air inlet 4 is connected to the air outlet 2 of the second alkali spray tower via a pipe.

[0023] A two-stage alkaline washing process followed by a first-stage low-temperature water cooling method is employed to thoroughly remove impurities such as meal powder, oil droplets, and free fatty acids from the exhaust gas. The alkaline scrubbing liquid is cooled using both circulating cooling water and low-temperature water at 5-7°C. The cooled scrubbing liquid then comes into direct contact with the exhaust gas, carrying away heat.

[0024] To further address the technical issues of heat recovery and hexane disposal, this invention adopts the following technical solution: the waste heat recovery system in the oil leaching workshop further includes a resin adsorption-desorption mechanism, which is connected in two phases to the outlet of the secondary alkali spraying mechanism. The resin adsorption-desorption mechanism includes a resin tower. The exhaust gas is cooled to a suitable adsorption temperature and then introduced into the resin tower for adsorption.

[0025] After adsorption saturation, the resin tower is switched to desorption mode via a valve. The desorption process involves first introducing approximately 1 bar of direct steam for stripping, and then passing the stripped steam into the DT (Distillation Tank) to recover heat and hexane. Since the resin tower temperature is too high after steam desorption and unsuitable for adsorption, cooling is required using low-temperature water cooling to below 10°C. After water cooling, air is introduced to purge moisture from the resin tower. Once dried, the resin tower can enter standby mode and can be switched back to adsorption mode at any time.

[0026] To further improve the technical problem of waste heat recovery efficiency, the present invention adopts the following technical solution: the falling film evaporator is provided with a condensate inlet and a condensate outlet, and the condensate outlet is connected to the top of the falling film evaporator via a circulating pump;

[0027] The falling film evaporator is connected to a superheated steam preheater via a steam jet pump.

[0028] After being filtered by a cyclone separator, the exhaust gas is introduced into a falling film evaporator by an induced draft fan to heat the steam condensate in the evaporation workshop. Using negative pressure evaporation technology, the steam condensate evaporated under negative pressure is pumped into a superheater by a jet pump and heated into superheated steam before being fed into the DT (Digital Transformer) for direct steam use.

[0029] To solve the technical problem of how to implement the bottom interlayer, the present invention adopts the following technical solution: a bottom interlayer is provided on the pre-dried layer, including a top plate and a bottom plate, and the top plate and the bottom plate are connected by evenly distributed rivets;

[0030] The top plate is provided with several groups of ventilation holes, each group of ventilation holes being a polygonal structure composed of several ventilation holes, with the ventilation holes being smaller at the top and larger at the bottom.

[0031] The bottom and top plates of the lower interlayer are fixed with rivets, making the upper interlayer less prone to deformation and preventing the stirring blades from rubbing against the bottom. The use of vent holes that are smaller at the top and larger at the bottom solves the problem of clogging in the pre-drying layer's pores.

[0032] To solve the technical problem that insufficient contact between materials and cold air affects the heat exchange effect, this utility model adopts the following technical solution: stirring fins are provided in the pre-drying layer, and a pusher plate is provided on the material-facing surface of the stirring fins to push the material forward.

[0033] The top of the end of the stirring blade is provided with a lifting plate for throwing materials upward.

[0034] This invention adds a pusher plate and a lifting plate to the stirring fins, which allows the stirring fins to push more material to move and lift the material upwards, so that the material is in a state of stirring and upward flow. In this way, the material and the cold air can fully contact and exchange heat, and the heat energy and n-hexane can be fully blown out.

[0035] To address the technical problem of rising hot air carrying away material, this invention adopts the following technical solution: the pre-drying layer has an air inlet, an air outlet, and a feed inlet, with the material on the pre-drying layer covering the bottom of the feed inlet. The feed inlet is inserted below the material layer to prevent the rising hot air from carrying away the material.

[0036] To solve the technical problem of uneven water cooling, this utility model adopts the following technical solution: a water distribution pipe is installed at the top of the resin tower to make water cooling more uniform.

[0037] To solve the technical problem of uneven steam stripping, this utility model adopts the following technical solution: a steam distribution pipe is installed at the top of the resin tower to make the steam stripping more uniform.

[0038] To address the technical problem of uneven waste gas intake, this invention employs the following technical solution: a distribution hood is installed at the bottom of the resin adsorption tower or resin desorption tower, with evenly distributed air inlet holes on the distribution hood for uniform waste gas intake. The waste gas from the resin tower inlet enters the resin tower through the air inlet holes of the distribution hood, resulting in more uniform waste gas distribution. Attached Figure Description

[0039] Figure 1a This is a process flow diagram of the waste heat recovery system for the oil leaching workshop of this utility model;

[0040] Figure 1b This is the second flowchart of the waste heat recovery system for the oil leaching workshop of this utility model;

[0041] Figure 1c This is the process flow diagram three of the waste heat recovery system for the oil leaching workshop of this utility model;

[0042] Figure 1d This is the overall process flow diagram of the waste heat recovery system in the oil leaching workshop of this utility model;

[0043] Figure 2a This is a schematic diagram of the pre-drying layer of this utility model;

[0044] Figure 2b This is a top view of the pre-dried layer of this utility model;

[0045] Figure 2c This is a perspective view of the bottom interlayer of the pre-dried layer of this utility model;

[0046] Figure 2d This is a cross-sectional view of the bottom interlayer of the pre-dried layer of this utility model;

[0047] Figure 2e This is a schematic diagram of the top plate of the bottom interlayer of the pre-drying layer of this utility model;

[0048] Figure 2f This is a schematic diagram of the structure of the stirring fins of the pre-drying layer of this utility model;

[0049] Figure 2g This is a side view of the stirring fins of the pre-drying layer of this utility model;

[0050] Figure 3a This is a schematic diagram of the structure of the resin tower of this utility model;

[0051] Figure 3b This is a schematic diagram of the water distribution pipe of the resin tower of this utility model;

[0052] Figure 3c This is a schematic diagram of the steam distribution pipe of the resin tower of this utility model;

[0053] In the diagram: 1. Second waste heat recovery unit; 2. Fan;

[0054] 3. Pre-drying layer; 310. Cylinder body; 320. Agitator fins; 321. Pusher plate; 322. Lifting plate; 330. Bottom jacket; 331. Top plate; 3310. Vent hole; 332. Bottom plate; 333. Tie nail; 340. Feed inlet; 350. Air inlet; 360. Air outlet; 370. Material;

[0055] 4. Pre-drying lacquer; 5. Exhaust fan; 6. Falling film evaporator; 7. Circulating pump; 8. Steam jet pump; 9. Superheated steam preheater; 10. First waste heat recovery unit I; 11. First waste heat recovery unit II; 12. Airlock; 13. Primary alkali spray tower; 14. First circulating pump; 15. Water cooler; 16. Secondary alkali spray tower; 17. Circulating pump; 18. Low temperature water cooler; 19. Surface cooler; 20. Resin tower I; 21. Resin tower II; 22. Resin tower III; 23. Exhaust fan; 24. Purge fan. Detailed Implementation

[0056] Among existing energy-saving and consumption-reducing technologies in leaching workshops, pre-drying technology involves adding a pre-drying layer to recover heat energy, but the pre-drying exhaust gas requires end-of-pipe treatment, resulting in high costs and ineffective solvent recovery. Paraffin oil adsorption suffers from high steam consumption and substandard treatment.

[0057] like Figure 1a , 1b As shown in 1c and 1d, this embodiment provides a waste heat recovery system for an oil leaching workshop, including an evaporation dryer, a falling film evaporator 6, a first waste heat recovery unit, and a second waste heat recovery unit.

[0058] The desiccant dryer includes a desiccant mechanism and a drying mechanism. A pre-drying layer 3 is provided on the drying mechanism. An additional pre-drying layer is added to the traditional vertical dryer as a deep desolventizing layer. A small-volume fan 2 is used to blow off n-hexane and water vapor from the wet meal. The small-volume fan performs deep desolventizing on the wet meal while recovering waste heat.

[0059] like Figure 2a , 2b As shown, the pre-drying layer 3 includes a cylinder 310, stirring blades 320, and a bottom jacket 330. An air inlet 350 and an air outlet 360 are provided on the cylinder 310. A dust removal device 4 is installed on the air outlet 360. The dust removal device 4 is preferably a cyclone separator. An airlock 12 is installed on the dust removal device 4 to dry collect recyclable meal powder, while simultaneously reducing wastewater generation.

[0060] In one embodiment, the pre-drying layer 3 includes a cylinder 310, stirring fins 320, and a bottom jacket 330.

[0061] In one embodiment, the cylinder 310 is provided with an air inlet 350, an air outlet 360, and a feed inlet 340. The material 370 on the bottom jacket 330 covers the bottom of the feed inlet 340. The feed inlet is inserted below the material layer to prevent the rising hot air from carrying away the material.

[0062] like Figure 2c , 2d As shown, the bottom interlayer 330 includes a top plate 331 and a bottom plate 332. The top plate 331 and the bottom plate 332 are connected by evenly distributed rivets 333. The top and bottom plates of the bottom interlayer are fixed with rivets, which makes the upper interlayer less prone to deformation and prevents the stirring blades from rubbing against the bottom.

[0063] The top plate 331 has several groups of ventilation holes, each group forming a polygonal structure composed of several ventilation holes 3310. A hexagonal structure is preferred. Figure 2e As shown, the vent 3310 has a structure with a smaller upper vent and a larger lower vent. By improving the structure of the pre-drying layer and adopting a vent with a smaller upper vent and a larger lower vent, the problem of pore blockage in the pre-drying layer is solved.

[0064] In one embodiment, such as Figure 2f , 2g As shown, a pusher plate 321 is provided on the material-facing surface of the end of the stirring blade 320 to push the material forward. A lifting plate 322 is provided on the top of the end of the stirring blade 320 to throw the material upward.

[0065] This invention adds a pusher plate and a lifting plate to the stirring fins, which allows the stirring fins to push more material to move and lift the material upwards, so that the material is in a state of stirring and upward flow. In this way, the material and the cold air can fully contact and exchange heat, and the heat energy and n-hexane can be fully blown out.

[0066] In one embodiment, the falling film evaporator 6 is provided with a condensate inlet, a condensate outlet, a hot air inlet, and a hot air outlet. The condensate outlet is connected to the top of the falling film evaporator 6 via a circulating pump 7. The hot air inlet of the falling film evaporator 6 is connected to the air outlet of the dust removal device 4.

[0067] In one embodiment, the falling film evaporator 6 is connected to the superheated steam preheater 9 via a steam jet pump 8.

[0068] After being filtered by a cyclone separator, the exhaust gas is introduced into the falling film evaporator 6 by the induced draft fan 5 to heat the steam condensate in the evaporation workshop. Using negative pressure evaporation technology, the steam condensate after negative pressure evaporation is pumped into the superheater 9 by the jet pump 8 and heated into superheated steam before being introduced into the DT for direct steam use.

[0069] The first waste heat recovery unit is used for heat exchange of circulating water. The first waste heat recovery unit is preferably a heat exchanger. The number of first waste heat recovery units is preferably two. The first waste heat recovery unit 10 and the second waste heat recovery unit 11 are connected in series. The first waste heat recovery unit 10 is connected to the hot air outlet of the falling film evaporator 6.

[0070] The second waste heat recovery unit 1 is used for heat exchange of cold air. The second waste heat recovery unit 1 is preferably a heat exchanger. The second waste heat recovery unit 1 is connected to the first waste heat recovery unit 11. After the cold air is heat-exchanged by the second waste heat recovery unit 1, it is introduced into the air inlet 350 of the pre-drying layer 3 by the fan 2.

[0071] The hot air, after recovering some heat energy through the falling film evaporator 6, is discharged into the first waste heat recovery unit 10, the second waste heat recovery unit 11, and the second waste heat recovery unit 1 for further waste heat recovery. Circulating water is introduced into the first waste heat recovery unit 10 and the second waste heat recovery unit 11 to exchange heat with the hot air and recover heat energy. The second waste heat recovery unit 1 at the end uses air-to-air heat exchange for further heat energy recovery.

[0072] In one embodiment, the waste heat recovery system in the oil leaching workshop further includes a primary alkali spraying mechanism, comprising a first alkali spraying tower 13, a first circulating pump 14, and a water cooler 15.

[0073] The first alkali spray tower 13 is equipped with an air inlet 1, an air inlet 2, an alkali inlet 1, an air outlet 1, and a condensate outlet 1. The air inlet 1 is used to introduce hot air after heat exchange by the second waste heat recovery unit 1, and the air inlet 2 is used to introduce exhaust gas from the oil leaching workshop.

[0074] The water cooler 15 is equipped with a circulating water inlet and a circulating water outlet.

[0075] The water cooler 15 is equipped with an inlet pipe and an outlet pipe. The inlet pipe is connected to the bottom of the first alkali spray tower 13 via the first circulating pump 14; the end of the outlet pipe is located inside and at the top of the first alkali spray tower 13 and is used for spraying alkali solution.

[0076] In one embodiment, the waste heat recovery system in the oil leaching workshop further includes a secondary alkali spraying mechanism, comprising a second alkali spraying tower 16, a second circulating pump 17, a low-temperature water cooler 18, and a surface cooler 19.

[0077] The second alkali spray tower 16 is equipped with an air inlet 3, an alkali liquid inlet 2, a condensate outlet 2, and an air outlet 2. The air inlet 3 and the air outlet 1 are connected by a pipeline.

[0078] The low-temperature water cooler 18 is equipped with two chilled water inlets and two chilled water outlets. The low-temperature water cooler 18 is also equipped with two liquid inlets and two liquid outlets. The liquid inlet pipe 2 is connected to the bottom of the second alkali spray tower 16 via the second circulating pump 17. The end of the liquid outlet pipe 2 is located at the top inside the second alkali spray tower 16 and is used for spraying alkali solution.

[0079] The surface cooler 19 is equipped with a chilled water inlet 1, a chilled water outlet 1, a condensate outlet, an air inlet 4, and an air outlet 3. The chilled water outlet 192 is connected to the chilled water inlet 2 of the low-temperature water cooler 18 via a pipe, and the air inlet 4 194 is connected to the air outlet 2 of the second alkali spray tower 16 via a pipe.

[0080] In one embodiment, the waste heat recovery system of the oil leaching workshop further includes a resin adsorption-desorption mechanism, which is connected to the outlet of the secondary alkali spraying mechanism. The resin adsorption-desorption mechanism includes a resin tower.

[0081] After the exhaust gas is cooled to a suitable adsorption temperature, it is introduced into the resin tower for adsorption. Generally, a two-desorption-one-adsorption mode, or a one-desorption-one-adsorption or two-desorption-two-adsorption mode is adopted. In this embodiment, there are three resin towers, including resin tower 20, resin tower 21, resin tower 22, exhaust fan 23, and purge fan 24.

[0082] In one embodiment, such as Figure 3a , 3b As shown, taking resin tower 20 as an example, a water distribution pipe 2010 is installed at the top of resin tower 20. In one embodiment, the water distribution pipe 2010 includes a main water distribution pipe 2011. A first water distribution pipe 2012 and a second water distribution pipe 2013 are installed on the main water distribution pipe 2011. Using the above-described water-cooled distribution method makes water cooling more uniform.

[0083] In one embodiment, such as Figure 3a , 3c As shown, taking resin tower 20 as an example, a steam distribution pipe 2020 is installed at the top of resin tower 20. The steam distribution pipe 2020 includes a main steam distribution pipe 2021. Steam distribution branch pipe one 2022 and steam distribution branch pipe two 2023 are installed on the main steam distribution pipe 2021. By adopting the above steam distribution method, the steam stripping is more uniform.

[0084] In one embodiment, an air inlet is provided at the bottom of the resin tower 20. A distribution hood 2030 is provided at the bottom of the resin tower 20, with evenly distributed air inlet holes for uniformly introducing exhaust gas. The exhaust gas distribution hood at the bottom makes the exhaust gas distribution more uniform.

[0085] The hot air temperature after heat exchange is 40-50℃, and this hot air contains approximately 2000 mg / L n-hexane. Direct emission of this hot air pollutes the environment and wastes resources. Therefore, this process employs resin adsorption to combine this hot air with the workshop exhaust gas for unified treatment. A two-stage alkaline scrubbing followed by a one-stage low-temperature water cooling method is used to thoroughly remove impurities such as meal powder, oil droplets, and free fatty acids from the exhaust gas. The alkaline scrubbing liquid is cooled using circulating cooling water and low-temperature water at 5-7℃. The cooled scrubbing liquid directly contacts the exhaust gas, carrying away heat. The exhaust gas after two-stage alkaline scrubbing enters a surface cooler for further temperature reduction. After adsorption saturation, the resin tower enters the desorption state via valve switching. The resin tower desorption process involves first introducing approximately 1 bar of direct steam for stripping, and then passing the stripped steam into the DT (Desiccant Tank) to recover heat and n-hexane. Since the resin tower temperature is too high after steam desorption and unsuitable for further adsorption, it needs to be cooled to below 10℃ using low-temperature water cooling. After being cooled by water, air is introduced into the resin tower to purge the moisture. Once dried, the resin tower can enter standby mode and can be switched to adsorption mode at any time.

[0086] The exhaust air contains a large amount of water vapor, resulting in a high temperature, typically reaching 95°C, and also contains n-hexane. A four-stage heat recovery process is employed, consisting of a falling film evaporator, a two-stage hot water heat exchanger, and a terminal preheater, to fully recover heat energy. Even after heat recovery, the exhaust gas still contains a significant amount of n-hexane and is directly emitted.

[0087] This invention uses adsorption resin instead of existing mineral oil adsorption, while simultaneously treating the pre-dried tail gas. This invention can recover heat energy, deeply remove solvents from the meal, and fully recover n-hexane from both the pre-dried tail gas and the system tail gas.

[0088] This integrated pre-drying adsorption device can deeply recover n-hexane and replace traditional paraffin oil adsorption, achieving emission standards in one step while saving steam and recovering solvent resources, thus increasing the economic benefits for enterprises. This invention can recover heat energy and efficiently recover n-hexane from system exhaust gas and pre-drying exhaust gas, reducing consumption and protecting the environment.

Claims

1. A waste heat recovery system for an oil leaching workshop, characterized in that, include: An evaporation dryer includes an evaporation mechanism and a drying mechanism. A pre-drying layer is provided on the drying mechanism. An air inlet and an air outlet are provided on the pre-drying layer. A dust removal device is provided on the air outlet. The falling film evaporator is connected to a dust removal device via an induced draft fan; Several first waste heat recovery units are connected in series for heat exchange of circulating water, and the first first waste heat recovery unit is connected to the hot air outlet provided on the falling film evaporator. The second waste heat recovery unit is used for heat exchange of cold air. The second waste heat recovery unit is connected to the first waste heat recovery unit at the tail. After the cold air is heat exchanged by the second waste heat recovery unit, it is introduced into the air inlet of the pre-drying layer by the fan.

2. The waste heat recovery system for the oil leaching workshop according to claim 1, characterized in that, The waste heat recovery system in the oil leaching workshop also includes a primary alkali spraying mechanism, comprising: The first alkali spray tower is equipped with an air inlet 1, an air inlet 2, an alkali liquid inlet 1, an air outlet 1, and a condensate outlet 1; the air inlet 1 is used to introduce hot air after heat exchange by the second waste heat recovery unit, and the air inlet 2 is used to introduce exhaust gas from the oil leaching workshop. A water cooler is connected to the first alkali spray tower via a first circulating pump; the water cooler is provided with a circulating water inlet and a circulating water outlet; the water cooler is provided with a liquid outlet pipe, the end of which is located inside the first alkali spray tower for spraying alkali solution.

3. The waste heat recovery system for the oil leaching workshop according to claim 2, characterized in that, The waste heat recovery system in the oil leaching workshop also includes a secondary alkaline spraying mechanism, comprising: The second alkali spray tower is equipped with an air inlet three, an alkali liquid inlet two, a condensate outlet two, and an air outlet two; the air inlet three and the air outlet one are connected by a pipeline. A low-temperature water cooler is connected to the second alkali spray tower via a second circulating pump; the low-temperature water cooler is provided with a second chilled water inlet and a second chilled water outlet; the low-temperature water cooler is provided with a second liquid outlet pipe, the end of which is located inside the second alkali spray tower for spraying alkali solution; The surface cooler is provided with a chilled water inlet 1, a chilled water outlet 1, a condensate outlet, an air inlet 4, and an air outlet 3. The chilled water outlet is connected to the chilled water inlet 2 of the low-temperature water cooler via a pipe, and the air inlet 4 is connected to the air outlet 2 of the second alkali spray tower via a pipe.

4. The waste heat recovery system for the oil leaching workshop according to claim 3, characterized in that, The waste heat recovery system in the oil leaching workshop also includes a resin adsorption and desorption mechanism, which is connected to the outlet of the secondary alkaline spraying mechanism. The resin adsorption and desorption mechanism includes a resin tower.

5. The waste heat recovery system for the oil leaching workshop according to claim 1, characterized in that, The falling film evaporator is provided with a condensate inlet and a condensate outlet, and the condensate outlet is connected to the top of the falling film evaporator via a circulating pump; The falling film evaporator is connected to a superheated steam preheater via a steam jet pump.

6. The waste heat recovery system for the oil leaching workshop according to claim 1, characterized in that, A bottom interlayer is provided on the pre-dried layer, including a top plate and a bottom plate, wherein the top plate and the bottom plate are connected by evenly distributed rivets; The top plate is provided with several groups of ventilation holes, each group of ventilation holes being a polygonal structure composed of several ventilation holes, with the ventilation holes being smaller at the top and larger at the bottom.

7. The waste heat recovery system for the oil leaching workshop according to claim 6, characterized in that, The pre-drying layer is provided with stirring fins, and the material-facing end of the stirring fins is provided with a pusher plate to push the material forward. The top of the end of the stirring blade is provided with a lifting plate for throwing materials upward.

8. The waste heat recovery system for the oil leaching workshop according to claim 7, characterized in that, The pre-drying layer is provided with an air inlet, an air outlet, and a feed inlet, and the material on the pre-drying layer covers the bottom of the feed inlet.

9. The waste heat recovery system for the oil leaching workshop according to claim 4, characterized in that, The resin tower is equipped with water distribution pipes and steam distribution pipes.

10. The waste heat recovery system for the oil leaching workshop according to claim 9, characterized in that, The bottom of the resin tower is provided with a distribution cover, on which air inlet holes are evenly distributed for uniformly introducing waste gas.

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