A resource-based environmentally friendly treatment system for glyphosate crystal liquid

Abstract

The present invention provides a system for resource-based environmental protection treatment of glyphosate crystal liquid, comprising an adiabatic incinerator 1, a waste heat boiler 9, a quenching tower 12, a bag filter 14, a deacidification tower 15, a cyclone plate demister 16, a flue gas heater 18, an SCR denitration device 20, an air preheater 21, an induced draft fan 22 and a chimney 23 arranged in sequence; the adiabatic incinerator 1 adopts a U-shaped structure, and a 5° inclined flue is arranged at the bottom of the U-shaped structure; the adiabatic incinerator 1, the waste heat boiler 9, the quenching tower 12 and the bag filter 14 are respectively provided with a salt recovery device. The present invention also discloses a system method for resource-based environmental protection treatment of glyphosate crystal liquid. The present invention can realize resource-based environmental protection treatment of glyphosate crystal liquid, and effectively and highly purifiedly classify and recover inorganic salts in glyphosate crystal liquid, so as to realize reduction, harmlessness, resource utilization and energy utilization.

Description

Technical Field

[0001] The invention relates to a glyphosate waste liquid treatment technology, and in particular to a glyphosate crystal liquid resource recovery and environmental protection treatment system. Background Art

[0002] Glyphosate is the most commonly used herbicide and the pesticide with the largest production and sales volume. Glyphosate mother liquor is a byproduct of glyphosate production and contains 1% of glyphosate, which is a hazardous waste. Glyphosate mother liquor contains glyphosate, glyphosate-enhanced, methyl glyphosate, phosphate, sodium chloride, sodium hydroxide and other substances, of which sodium chloride is more than 14-18%. If glyphosate mother liquor is recycled, it will save the production cost of the enterprise and improve the overall competitiveness of the enterprise. The treatment method of glyphosate mother liquor has become an important issue for the production and survival of enterprises.

[0003] Incineration technology is a simple, efficient and feasible method for treating waste liquid. It is used to treat organic waste liquid that is difficult to biodegrade, has high concentration, high toxicity and complex composition. In the "14th Five-Year Plan", my country's ecological and environmental protection has entered a new stage of coordinated governance of pollution reduction and carbon reduction. The environmental protection industry will also take carbon reduction as the general grasp to achieve green and low-carbon development and achieve carbon peak and carbon neutrality goals. Green and low-carbon technologies are urgently needed. Therefore, for glyphosate mother liquor, it is first concentrated into glyphosate crystal liquid (sodium chloride content is about 27%) and then incinerated.

[0004] Regarding the treatment and utilization of glyphosate mother liquor, the incineration treatment system currently used basically does not classify the products after incineration for resource utilization, and still requires secondary treatment, with low recycling value; or salt separation is carried out, but the treatment process is too complicated and the project cost is high.

[0005] The existing patent CN1052376A (a system for resource utilization of glyphosate mother liquor) proposes that a constant temperature incinerator controls the furnace temperature at 650-750°C. The glyphosate mother liquor is dried, pyrolyzed and oxidized in the constant temperature incinerator. The larger solid particles that are not completely burned and the smaller solid particles separated by the cyclone separator are sent to the large scale chain grate for further incineration, and the residual organic matter is completely removed to recover sodium pyrophosphate. The melting point of sodium chloride is 801°C, and the melting point of sodium pyrophosphate is 880°C. This device is limited by the temperature resistance of the chain grate, and the incineration temperature is controlled below 750°C. The sodium chloride and sodium pyrophosphate collected by the incinerator at this temperature are not melted, but are solid, and there will be impurities between the lattices. Moreover, the two salts are mixed together and are not collected by classification, which is a miscellaneous salt with low recycling value.

[0006] The existing patent CN106082515A (a process for incineration of glyphosate mother liquor) proposes the use of membrane separation, primary oxidation, secondary crystallization separation, incineration system incineration and other steps; organic matter is intercepted by a membrane treatment device and a membrane separation system, and the permeate obtained by the membrane treatment device is evaporated and concentrated, and then sodium chloride industrial salt is obtained by secondary crystallization, and then incineration treatment is performed at an incineration temperature of 800-1000°C to obtain sodium pyrophosphate. This treatment process ultimately adopts incineration, but the initial treatment process is relatively cumbersome. Summary of the invention

[0007] The purpose of the present invention is to propose a resource-based environmental protection treatment system for glyphosate crystal liquid, in view of the problem that the existing treatment of glyphosate crystal liquid cannot classify and recover salts or the process of classifying and recovering salts is complicated and cumbersome. The system can quickly and effectively realize the resource-based environmental protection treatment of glyphosate crystal liquid, and classify and grade high-purity inorganic salts for direct use in production.

[0008] To achieve the above object, the technical solution adopted by the present invention is: a glyphosate crystal liquid resource environmental protection treatment system, including an adiabatic incinerator, a waste heat boiler, a quenching tower, a bag filter, a deacidification tower, a cyclone plate demister, a flue gas heater, an SCR denitrification device, an air preheater, an induced draft fan and a chimney arranged in sequence;

[0009] The adiabatic incinerator adopts a U-shaped structure, and a 5° inclination angle is set at the bottom connection of the U-shaped structure to prevent the accumulation of salt droplets carried by the flue gas after falling here, so that the droplets can flow along the inclination angle to the molten salt pool; salt recovery devices are respectively set at the bottom of the adiabatic incinerator and the waste heat boiler.

[0010] Furthermore, the adiabatic incinerator adopts a combustion method of top-spraying waste liquid and side-burning natural gas, that is, a plurality of waste liquid atomizing spray guns are arranged on the top of the furnace of the adiabatic incinerator, and the spray angles of adjacent spray guns of the plurality of waste liquid atomizing spray guns do not interfere with each other and do not touch the furnace wall. Two afterburning burners are arranged in the molten salt pool at the bottom of the adiabatic incinerator.

[0011] Furthermore, three layers of natural gas burners are arranged on the upper and middle furnace walls of the adiabatic incinerator, and each layer of natural gas burners is arranged in a four-corner cut circle.

[0012] Furthermore, three sonic soot blowers are provided at the U-shaped rear half of the adiabatic incinerator, which help to recover the sodium chloride as completely as possible in the adiabatic incinerator.

[0013] Furthermore, the adiabatic incinerator comprises two cylindrical furnaces, and the bottoms of the two cylindrical furnaces are connected by a flue with a 5° inclination angle, forming a U-shaped structure. The adiabatic incinerator is composed of refractory bricks, insulation bricks and carbon steel shell from the inside to the outside on the smoke side, and reinforcing ribs are arranged outside the carbon steel shell to support and reinforce the furnace body.

[0014] Furthermore, the adiabatic incinerator is provided with an explosion-proof door to ensure the safe operation of the incineration system.

[0015] Furthermore, the furnace water-cooled wall of the waste heat boiler adopts a fully welded membrane water-cooled wall structure, which is made by welding pipes and flat steel.

[0016] Furthermore, multiple steam soot blowers are arranged in the cooling chamber of the waste heat boiler to ensure that the molten salt does not adhere to the water-cooled wall of the waste heat boiler.

[0017] Furthermore, the waste heat boiler is divided into two cooling chambers, and a stainless steel plate is applied to the smoke side of the ash hopper castable at the lower part of the waste heat boiler to prevent the collected phosphate from sticking to the castable.

[0018] Furthermore, a venturi tube is provided on the flue between the quenching tower and the bag filter, and interfaces of an activated carbon injection device and a slaked lime injection device are arranged on the venturi tube.

[0019] Furthermore, the bag filter adopts a compartment structure for online detection and online bag replacement, which allows the incineration system to detect and replace damaged bags without stopping the furnace.

[0020] Furthermore, the deacidification tower is in the form of an empty tower and arranged vertically. A three-layer spray device is arranged inside the deacidification tower, which can make the alkali solution fully contact with the flue gas and improve the deacidification efficiency.

[0021] Furthermore, two layers of demisters are designed on the top of the desulfurization tower to remove moisture carried in the flue gas, and a flue-type cyclone plate demister is arranged on the flue at the outlet of the desulfurization tower. The double demisting method can remove water mist more efficiently.

[0022] Furthermore, a flue gas heater is arranged in front of the SCR denitrification device to heat the flue gas to a temperature required for medium and low temperature denitrification.

[0023] Furthermore, an air preheater is arranged after the SCR denitration device to exchange heat between the exhaust flue gas and the combustion air of the adiabatic incinerator, thereby increasing the inlet temperature of the combustion air, saving auxiliary fuel, recovering the waste heat of the flue gas and reducing the exhaust temperature of the flue gas.

[0024] Furthermore, the molten salt at the bottom of the adiabatic incinerator is liquid, and a liquid seal structure is adopted at the overflow port; the salt discharged from the ash outlet of the waste heat boiler, quenching tower and bag filter lower ash hopper is solid, and a double star discharge valve is adopted for sealed discharge to ensure the sealing of the entire system.

[0025] Furthermore, the salt recovery device, the two flow outlets of the molten salt pool at the bottom of the U-shaped adiabatic incinerator are respectively connected to the first biaxial cooler and the second biaxial cooler, and the first biaxial cooler and the second biaxial cooler are respectively connected to the first water-cooled scraper conveyor; the two ash hoppers at the bottom of the waste heat boiler are respectively connected to the third biaxial cooler and the fourth biaxial cooler, and the third biaxial cooler and the fourth biaxial cooler are respectively connected to the second water-cooled scraper conveyor; the lower ash hopper of the bag dust collector is respectively connected to the fourth water-cooled scraper conveyor and the fifth water-cooled scraper conveyor; the fourth water-cooled scraper conveyor and the fifth water-cooled scraper conveyor are respectively connected to the third water-cooled scraper conveyor.

[0026] Another object of the present invention is to disclose a resource-based environmental protection treatment system for glyphosate crystal liquid, which comprises the following steps: the glyphosate crystal liquid transported by the heat tracing pipeline is atomized and then sprayed into an adiabatic incinerator for incineration; the flue gas enters the waste heat boiler for heat exchange and then enters the quenching tower, and the quenching tower is sprayed with high-salt water after deacidification precipitation, and the flue gas after spraying enters the bag filter, and the flue gas coming out of the bag filter enters the deacidification tower to remove the acid gas in the flue gas, and the water carried in the flue gas after deacidification is further removed by the cyclone plate demister, and the flue gas after dust removal and deacidification is sent into the chimney by the induced draft fan after denitration and discharged into the atmosphere.

[0027] The glyphosate crystal liquid resource recovery and environmental protection treatment system of the present invention has the following advantages compared with the prior art:

[0028] 1. Adiabatic Incinerator

[0029] 1) In order to reduce the amount of auxiliary fuel, the present invention adopts an adiabatic incinerator with an incineration temperature between 1100 and 1200°C;

[0030] 2) The adiabatic incinerator adopts a U-shaped structure, and the lower connection of the U-shaped structure has a 5° inclination angle, which is conducive to the molten sodium chloride molten salt not accumulating at the connection, and can flow to the molten salt pool at the bottom of the incinerator;

[0031] 3) Three layers of natural gas burners are arranged on the upper and middle walls of the adiabatic incinerator. Each layer of natural gas burners adopts a four-corner cut circle layout to ensure the continuity, stability, safety, and reliability of incineration. The air distribution fully considers environmental protection requirements and adopts low NOx air distribution to inhibit the generation of nitrogen oxides. These measures can ensure that the glyphosate crystal liquid burns fully and efficiently;

[0032] 4) The melting point of sodium chloride is 801°C and the boiling point is 1465°C; the melting point of sodium pyrophosphate is 880°C and the boiling point is 938°C. In the adiabatic incinerator of this system, sodium chloride is in a molten state and sodium pyrophosphate is in a gaseous state. Therefore, the present invention sets salt recovery devices at the bottom of the adiabatic incinerator and the waste heat boiler respectively. Sodium chloride is recovered at the bottom of the adiabatic incinerator; sodium pyrophosphate is recovered at the bottom of the waste heat boiler;

[0033] 5) In order to ensure that the sodium chloride can be recovered as completely as possible in the incinerator, three sonic soot blowers 6 are provided in the rear half of the U-shaped adiabatic incinerator. The vibration caused by the sound waves causes the sodium chloride droplets of different sizes that are about to be taken out of the incinerator to be driven up, resulting in different moving speeds. The small sodium chloride droplets will participate in the large-scale sound wave vibrations due to their small mass, and collide with the large droplets that are difficult to vibrate, and condense under the action of static electricity. The condensation increases the weight of the droplets, causing them to fall into the molten salt pool at the bottom of the incinerator, reducing the possibility of the sodium chloride droplets being taken out of the adiabatic incinerator;

[0034] 6) The adiabatic incinerator adopts the combustion method of top-spraying waste liquid and side-burning natural gas, that is, a waste liquid atomizing spray gun is arranged on the top of the adiabatic incinerator furnace, and the glyphosate crystal liquid transported with heat is atomized by low-pressure steam in the waste liquid atomizing spray gun and sprayed into the furnace for incineration. The arrangement of the waste liquid atomizing spray gun must ensure that the glyphosate crystal liquid is evenly sprayed on the cross section of the furnace after atomization, creating conditions for a uniform flue gas dynamic field. The spray angles of adjacent spray guns do not interfere with each other and do not touch the furnace wall;

[0035] 7) The U-shaped adiabatic incinerator consists of two left and right cylinders and a 5° inclined flue between the bottoms of the two cylinders. From the inside to the outside, the smoke-facing side is made up of refractory bricks, insulation bricks and a carbon steel shell. Reinforcement ribs are set outside the shell to support and reinforce the furnace body. The flue gas temperature at the outlet of the adiabatic incinerator is ≥1100℃, and the residence time of the flue gas in the adiabatic incinerator is greater than 2s;

[0036] 8) The adiabatic incinerator is equipped with an explosion-proof door. When the pressure inside the incinerator exceeds a certain value, the gravity cover of the explosion-proof door automatically opens, instantly releasing the pressure to achieve the purpose of protecting the equipment;

[0037] 2. Waste Heat Boiler

[0038] 9) The water-cooled wall of the waste heat boiler furnace adopts a fully welded membrane water-cooled wall structure, which is made of pipes and flat steel to ensure the tightness of the furnace under any operating conditions. The waste heat boiler water-cooled screen is suspended on the steel frame through the upper hanger of the upper header. Multiple layers of rigid beams with sufficient strength are set from top to bottom on the periphery of the waste heat boiler to ensure that the furnace has sufficient resistance to external and internal explosions;

[0039] 10) The salts carried by the flue gas adhere to the membrane wall and the water-cooled screen. At the same time, low-temperature steam and water flow inside the membrane wall and the water-cooled screen. At the contact surface between the salts and the membrane wall and the water-cooled screen, the heat carried by the salts is quickly taken away, forming a brittle film here. As the salts adhered to the membrane surface increase in weight, they will fall off by themselves under the action of gravity. At the same time, multiple steam soot blowers are arranged in the cooling room of this waste heat boiler. Due to the existence of the brittle film, the salts hanging on the wall can be easily blown off by blowing.

[0040] 11) The waste heat boiler is divided into two cooling chambers. The flue gas temperature at the outlet of the rear cooling chamber is 500-550℃. The ash hopper castable at the lower part of the waste heat boiler is coated with a stainless steel plate on the flue side to prevent the molten salt from sticking to the castable;

[0041] 3.Quick cooling tower

[0042] 12) A venturi tube is installed on the flue between the quench tower and the bag filter. The venturi tube is provided with interfaces for activated carbon injection device and slaked lime injection device. The generation of dioxin-like harmful substances is suppressed by injecting activated carbon powder and slaked lime powder into the flue gas.

[0043] 13) Based on the principle of energy conservation and water saving to reduce sewage discharge as much as possible, and considering that high-salt wastewater has no disadvantages for quenching spray, the present invention recycles the high-salt water after deacidification to spray and cool the quenching tower. In order to prevent the high-salt water from causing wear on the quenching water pump, etc., a quenching circulation pool is set after the deacidification sedimentation tank, so that the deacidified water is allowed to stand in the sedimentation tank and then enter the quenching circulation pool;

[0044] 4. Bag Dust Collector

[0045] 14) The bag filter adopts a compartment structure with online detection and online bag replacement. That is, when the bag is damaged, the compartment where the damaged bag is located can be detected online, and the damaged bag can be replaced without stopping the furnace;

[0046] 5. Deacidification Tower

[0047] 15) The present invention adopts sodium deacidification. The deacidification tower is made of stainless steel. The deacidification tower is in the form of an empty tower and arranged vertically. A three-layer spray device is arranged inside the deacidification tower, which can make the alkali solution fully contact with the flue gas and improve the deacidification efficiency;

[0048] 16) During the deacidification process, the flue gas comes into contact with a large amount of alkali solution, causing the flue gas to carry a large amount of moisture. Direct discharge will cause serious problems such as water in the induced draft fan, equipment vibration, equipment corrosion, and white smoke. Therefore, a two-layer demister is designed on the top of the deacidification tower to remove the moisture carried in the flue gas;

[0049] 6. Cyclone plate demister

[0050] 17) In order to further remove the moisture carried in the deacidification flue gas, a cyclone plate demister 16 is installed in the flue gas outlet of the deacidification tower. The double demisting method can remove the water mist more efficiently. The flue gas temperature after deacidification is about 65℃;

[0051] 7. SCR Denitrification Device

[0052] 18) Since the glyphosate crystal liquid contains fuel-type nitrogen, a large amount of nitrogen oxides will be generated after high-temperature incineration. In order to ensure ultra-low flue gas emissions, the denitration part of the present invention adopts the form of SCR, and an SCR denitration device is arranged at the tail of the flue gas treatment system;

[0053] 19) A flue gas heater 18 is arranged in front of the SCR denitration device. The low-temperature flue gas after deacidification and demisting passes through the flue gas heater, and the flue gas heater burner is started to raise the flue gas temperature to above 220°C;

[0054] 20) The SCR denitrification device uses a low-temperature NOx honeycomb catalyst, and the optimal operating temperature is between 220 and 280°C;

[0055] 21) The flue gas temperature coming out of the SCR denitration device is about 220℃. Direct discharge will waste a lot of heat. In order to save natural gas consumption and reduce operating costs, an air preheater 21 is set after the denitration device to exchange heat between the combustion air of the adiabatic incinerator and the 220℃ flue gas after denitration. The air and the flue gas are countercurrently exchanged in the air preheater 21. The air is heated to about 170℃ and enters the adiabatic incinerator for incineration. The flue gas is cooled to about 130℃ and sent into the chimney by the induced draft fan and discharged into the atmosphere.

[0056] 8. Salt Collection System

[0057] 22) Three salt collection systems:

[0058] 1. The salt outlet at the bottom of the U-shaped adiabatic incinerator produces high-temperature molten sodium chloride salt. Therefore, a first double-axis cooler 24 and a second double-axis cooler 25 are provided at the bottom of the adiabatic incinerator to cool the discharged molten salt. The cooled solid salt falls into the first water-cooled scraper conveyor 26. The first water-cooled scraper conveyor 26 delivers the solid salt to the packaging workshop. After the salt is crushed by the first crusher, it is cooled again in the first roller slag cooler 27. The cooled salt particles are lifted into the hopper of the first baler 29 by the first sealed bucket elevator 28. The sodium chloride salt particles are packaged at the bottom of the baler by a packaging bag and stored in the workshop after packaging.

[0059] 2. The sodium pyrophosphate salt from the two cooling chambers of the waste heat boiler enters the third double-shaft cooler 30 and the fourth double-shaft cooler 31 respectively, and then enters the second water-cooled scraper conveyor 32. The second water-cooled scraper conveyor 32 delivers the solid salt to the packaging workshop, and after the salt is crushed by the second crusher, it is cooled again in the second drum slag cooler 33. The cooled salt particles are lifted to the hopper of the second baler 35 by the second sealed bucket elevator 34, and the sodium pyrophosphate salt particles are packaged at the bottom of the baler by a packaging bag, and stored in the workshop after packaging;

[0060] 3. The salt collected by the bag filter contains activated carbon and slaked lime powder, which is collected by the fourth water-cooled scraper conveyor 39 and the fifth water-cooled scraper conveyor 40 and then enters the third water-cooled scraper conveyor 38; the spray water of the quenching tower is high salt water after deacidification, and the collected salt components are relatively mixed. The solid salt recovered by the quenching tower and the bag filter can be sent to the adiabatic incinerator for incineration to eliminate the activated carbon powder and its dioxins and recover the inorganic salt.

[0061] 23) The molten salt at the bottom of the adiabatic incinerator is liquid, and a liquid seal structure is used at the overflow port; the waste heat boiler, quenching tower, and bag filter bottom are all solid discharge materials, and the ash hopper outlet at the bottom of the equipment uses a double star discharge valve for sealed discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a schematic diagram of the elevation structure of the glyphosate crystal liquid resource recovery and environmental protection treatment system;

[0063] Figure 2 This is a schematic diagram of the planar structure of the glyphosate crystal liquid resource recovery and environmental protection treatment system. DETAILED DESCRIPTION

[0064] The present invention is further described below in conjunction with embodiments:

[0065] Example 1

[0066] This embodiment discloses a system for recycling and environmentally friendly treatment of glyphosate crystal liquid. Figure 1 Figure 2 As shown, it includes an adiabatic incinerator 1, a waste heat boiler 9, a quenching tower 12, a bag filter 14, a deacidification tower 15, a cyclone plate demister 16, a flue gas heater 18, an SCR denitrification device 20, an air preheater 21, an induced draft fan 22 and a chimney 23 which are arranged in sequence;

[0067] The adiabatic incinerator 1 adopts a U-shaped structure, and a 5° inclined flue is arranged at the bottom connection of the U-shaped structure. The setting of the inclined flue is conducive to the molten sodium chloride salt not accumulating at the connection, and can flow to the molten salt pool at the bottom of the adiabatic incinerator by itself;

[0068] The melting point of sodium chloride is 801°C and the boiling point is 1465°C; the melting point of sodium pyrophosphate is 880°C and the boiling point is 938°C. The incineration temperature of the adiabatic incinerator 1 is between 1100 and 1200°C. In the adiabatic incinerator of this system, sodium chloride is in a molten state and sodium pyrophosphate is in a gaseous state. Therefore, salt recovery devices are respectively provided at the bottom of the adiabatic incinerator 1 and the waste heat boiler 9. The salt recovery device at the bottom of the adiabatic incinerator recovers sodium chloride and the like, and the salt recovery device at the bottom of the waste heat boiler recovers sodium pyrophosphate and the like.

[0069] The adiabatic incinerator adopts a combustion mode of top spraying of waste liquid and side burning of natural gas, that is, six waste liquid atomizing spray guns 5 are arranged on the top of the furnace of the adiabatic incinerator 1, and the spray angles of adjacent waste liquid atomizing spray guns 5 do not interfere with each other and do not touch the furnace wall. The glyphosate crystal liquid transported by heat tracing is sprayed into the furnace by low-pressure steam atomization in the waste liquid atomizing spray gun for incineration. The arrangement of the waste liquid atomizing spray gun should ensure that the glyphosate crystal liquid is evenly sprayed on the cross section of the furnace after atomization, creating conditions for a uniform flue gas dynamic field. The auxiliary fuel natural gas enters the adiabatic incinerator through the natural gas burner to burn and maintain the temperature in the incinerator. A total of 18 natural gas burners are arranged on the upper and middle furnace walls of the adiabatic incinerator. Each layer of natural gas burners adopts a four-corner cut circle arrangement to ensure the continuity, stability, safety, reliability, etc. of the incineration. The air distribution fully considers environmental protection requirements and adopts low NOx air distribution to inhibit the generation of nitrogen oxides. The above measures can ensure that the glyphosate crystal liquid burns fully and efficiently.

[0070] The U-shaped rear half of the adiabatic incinerator is provided with three sonic soot blowers 6 to ensure that the sodium chloride can be recovered as completely as possible in the incinerator part. The vibration caused by the sound waves causes the sodium chloride droplets of different sizes that are about to be taken out of the adiabatic incinerator to be driven up, resulting in different moving speeds. The small sodium chloride droplets will participate in the large-scale sound wave vibration due to their small mass, and collide with the large droplets that are difficult to vibrate, and condense under the action of static electricity. The condensation increases the weight of the droplets, causing them to fall into the molten salt pool at the bottom of the adiabatic incinerator, reducing the possibility of the sodium chloride droplets being taken out of the adiabatic incinerator.

[0071] The U-shaped adiabatic incinerator includes two cylinders and the bottoms of the two cylinders are connected by a 5° inclined flue. From the inside to the outside of the smoke side, there are refractory bricks, insulation bricks and carbon steel shells. Reinforcement ribs are arranged outside the carbon steel shell to support and reinforce the furnace body. The outlet flue gas temperature of the adiabatic incinerator is ≥1100℃, and the residence time of the flue gas in the adiabatic incinerator is greater than 2s. Two supplementary burners 2 are arranged in the molten salt pool at the bottom of the adiabatic incinerator 1 to ensure that the salts in the molten salt pool of the incinerator flow out of the furnace in a molten state.

[0072] The adiabatic incinerator 1 is provided with two explosion-proof doors 4. When the pressure inside the adiabatic incinerator exceeds a certain value, the gravity covers of the explosion-proof doors are automatically opened to release the pressure instantly, thereby achieving the purpose of protecting the equipment.

[0073] The furnace water-cooled wall of the waste heat boiler 9 adopts a fully welded membrane water-cooled wall structure, which is welded from pipes and flat steel to ensure the tightness of the furnace under any operating conditions. The waste heat boiler water-cooled panel is suspended on the steel frame through the upper suspension rod of the upper header. Multiple layers of rigid beams with sufficient strength are arranged from top to bottom on the periphery of the waste heat boiler, so that the furnace has sufficient resistance to external and internal explosions.

[0074] The salts carried by the flue gas adhere to the membrane wall and the water-cooled screen. At the same time, low-temperature steam and water flow inside the membrane wall and the water-cooled screen. At the contact surface between the salts and the membrane wall and the water-cooled screen, the heat carried by the salts is quickly taken away, forming a brittle film here. As the salts adhered to the membrane surface increase in weight, they also increase in weight, and will fall off by themselves under the action of gravity. At the same time, multiple steam soot blowers are arranged in the cooling chamber of the waste heat boiler. Due to the existence of the brittle film, the salts hanging on the wall can be easily blown off by blowing.

[0075] The waste heat boiler 9 is divided into two cooling chambers, and the flue gas temperature at the outlet of the rear cooling chamber is 500-550°C. The ash hopper castable at the lower part of the waste heat boiler 9 is coated with a stainless steel plate on the smoke side to prevent the molten salt from sticking to the castable.

[0076] A venturi tube is provided on the flue between the quench tower 12 and the bag filter 14. The venturi tube is provided with interfaces for an activated carbon injection device and a slaked lime injection device. Activated carbon powder and slaked lime powder are injected into the flue gas through the activated carbon injection device and the slaked lime injection device to suppress the generation of dioxin-like harmful substances.

[0077] In line with the principle of energy saving and water saving to reduce sewage discharge as much as possible, and considering that high-salt wastewater has no disadvantages for quenching spray, the present invention recycles the high-salt water after deacidification to spray and cool the quenching tower. In order to prevent the high-salt water from wearing the quenching water pump, etc., a quenching circulation pool is set after the deacidification sedimentation tank, so that the deacidified water is allowed to stand and settle in the sedimentation tank before entering the quenching circulation pool.

[0078] The bag filter 14 adopts a chamber structure for online detection and online bag replacement, that is, when a bag is damaged, the chamber where the damaged bag is located can be detected online, and the damaged bag can be replaced without stopping the furnace.

[0079] The present invention adopts sodium deacidification, and the deacidification tower 15 is made of stainless steel. The deacidification tower is in the form of an empty tower and arranged vertically. A three-layer spray device is arranged inside the deacidification tower, which can make the alkali solution fully contact with the flue gas and improve the deacidification efficiency.

[0080] During the deacidification process, the flue gas comes into contact with a large amount of alkali solution, causing the flue gas to carry a large amount of moisture. Direct discharge will cause serious problems such as water in the induced draft fan, equipment vibration, equipment corrosion, and white smoke. Therefore, a two-layer demister is designed on the top of the deacidification tower to remove the moisture carried in the flue gas;

[0081] In order to further remove the moisture carried in the deacidification flue gas, a cyclone plate demister 16 is provided at the outlet flue of the deacidification tower.

[0082] The double de-mist method can remove the mist more efficiently. The flue gas temperature after deacidification is about 65℃.

[0083] Since the glyphosate crystal liquid contains fuel-type nitrogen, a large amount of nitrogen oxides will be generated after high-temperature incineration. In order to ensure ultra-low flue gas emissions, the denitration part of the present invention adopts the form of SCR, that is, an SCR denitration device 20 is arranged at the tail of the flue gas treatment system. A flue gas heater 18 is arranged in front of the SCR denitration device 20. The flue gas after deacidification and demisting passes through the flue gas heater 18, and the flue gas heater burner 17 is started to raise the flue gas temperature to above 220°C. The SCR denitration device 20 uses a low-temperature NOx honeycomb catalyst, and the optimal operating temperature is between 220 and 280°C.

[0084] The temperature of the flue gas coming out of the SCR denitration device is about 220°C. Direct discharge will waste a lot of heat. In order to save natural gas consumption and reduce operating costs, an air preheater 21 is set after the SCR denitration device to exchange heat between the combustion air of the adiabatic incinerator and the 220°C flue gas after denitration. The air and the flue gas are countercurrently exchanged in the air preheater 21. The air is heated to about 170°C and enters the incinerator for incineration. The flue gas is cooled to about 130°C and sent into the chimney 23 by the induced draft fan 22 and discharged into the atmosphere.

[0085] The molten salt at the bottom of the adiabatic incinerator 1 is liquid, and a liquid seal structure is adopted at the overflow port; the ash outlets of the waste heat boiler 9, the quenching tower 12, and the lower ash hopper of the bag filter 14 all adopt double star discharge valves for sealed discharge, which are suitable for solid discharge and ensure the tightness of the entire system.

[0086] The salt collection system: the two molten salt pool overflow ports at the bottom of the adiabatic incinerator 1 are respectively connected to the first biaxial cooler 24 and the second biaxial cooler 25, and the first biaxial cooler 24 and the second biaxial cooler 25 are respectively connected to the first water-cooled scraper conveyor 26; the two ash hoppers at the bottom of the waste heat boiler 9 are respectively connected to the third biaxial cooler 30 and the fourth biaxial cooler 31, and the third biaxial cooler 30 and the fourth biaxial cooler 31 are respectively connected to the second water-cooled scraper conveyor 32; the lower ash hopper of the bag filter 14 is respectively connected to the fourth water-cooled scraper conveyor 39 and the fifth water-cooled scraper conveyor 40; the fourth water-cooled scraper conveyor 39 and the fifth water-cooled scraper conveyor 40 are respectively connected to the third water-cooled scraper conveyor 38.

[0087] The method of using the above system for the resource-based environmental protection treatment system of glyphosate crystal liquid is as follows:

[0088] The glyphosate crystal liquid from outside the boundary area is transported to the waste liquid buffer tank in the boundary area through a heating pipeline to stabilize the pressure and flow, and then is pressurized and transported to the waste liquid atomizing spray gun 5 located on the top of the adiabatic incinerator 1 by a waste liquid booster pump. Low-pressure steam is introduced to atomize the glyphosate crystal liquid and then sprayed into the adiabatic incinerator for incineration.

[0089] The adiabatic incinerator 1 adopts a combustion mode of top spraying waste liquid and side burning natural gas, that is, six waste liquid atomizing spray guns 5 are arranged on the top of the adiabatic incinerator furnace, and the glyphosate crystal liquid is sprayed into the furnace through low-pressure steam atomization in the waste liquid atomizing spray gun 5 for incineration. The arrangement of the waste liquid atomizing spray gun 5 should ensure that the glyphosate crystal liquid is evenly sprayed on the cross section of the furnace after atomization, creating conditions for a uniform flue gas dynamic field. The injection angles of adjacent waste liquid atomizing spray guns 5 do not interfere with each other and do not touch the furnace wall. The auxiliary fuel natural gas enters the adiabatic incinerator 1 through the natural gas burner to burn and maintain the temperature in the incinerator. A total of eighteen natural gas burners 3 are arranged on the upper and middle furnace walls of the adiabatic incinerator 1. Each layer of natural gas burners 3 adopts a four-corner cut circle arrangement to ensure the continuity, stability, safety, reliability, etc. of the incineration. The air distribution fully considers environmental protection requirements, adopts low NOx air distribution, and suppresses the generation of nitrogen oxides. The above measures can ensure that the glyphosate crystal liquid burns fully and efficiently.

[0090] At the same time, ensure a stable flue gas dynamic field in the furnace. Reasonably set the size of the incinerator furnace to ensure a reasonable flue gas flow rate (≈4.5m / s) in the furnace, ensure the combustion temperature (≥1100℃) and the residence time in the adiabatic incinerator is greater than 2s.

[0091] The main salts recovered from the incineration of the glyphosate crystal liquid are sodium chloride and sodium pyrophosphate. The melting point of sodium chloride is 801°C and the boiling point is 1465°C; the melting point of sodium pyrophosphate is 880°C and the boiling point is 938°C. Considering the large difference in the boiling points of sodium chloride and sodium pyrophosphate, in the incineration part, when the flue gas temperature is controlled at around 1100°C, sodium pyrophosphate is gaseous and sodium chloride is liquid. At this time, the collected salt is basically sodium chloride; in the waste heat boiler part, the collected salt is mainly sodium pyrophosphate. The salt at the bottom of the adiabatic incinerator and the waste heat boiler is collected separately to ensure the purity of the collected salt.

[0092] The adiabatic incinerator 1 is a U-shaped adiabatic incinerator, comprising two cylindrical furnaces and a connecting flue with a 5° inclination angle between the bottoms of the two furnaces. From the inside to the outside of the adiabatic incinerator facing the smoke side, refractory bricks, insulation bricks and a carbon steel shell are respectively provided, and reinforcing ribs are arranged outside the shell to support and reinforce the furnace body.

[0093] A temperature measuring point is arranged at the outlet flue of the U-shaped adiabatic incinerator. When the temperature at the measuring point is lower than 1100°C, the flow rate of the natural gas burner and the amount of air are adjusted to ensure that the flue gas temperature entering the waste heat boiler 9 is ≥1100°C.

[0094] After high-temperature combustion, the sodium chloride salt (melting point of 801°C, boiling point of 1465°C) in the glyphosate crystal liquid becomes molten and falls into the molten salt pool at the bottom of the two cylindrical furnaces of the adiabatic incinerator. The two molten salt pools at the bottom of the U-shaped adiabatic incinerator are both equipped with a supplementary combustion burner 2 to ensure that the molten salt in the molten salt pool does not condense into slag and has good fluidity. The molten salt flows out through the bottom flow ports of the two molten salt pools and falls into the first double-axis cooler 24 and the second double-axis cooler 25 arranged at the lower part for cooling. The cooled solid salt falls into the first water-cooled scraper conveyor 26 and is transported to the salt warehouse through the first crusher, the first roller slag cooler 27, the first sealed bucket elevator 28 and the first baler 29.

[0095] Flue gas above 1100℃ enters the waste heat boiler 9. The water-cooled wall of the furnace of the waste heat boiler 9 adopts a fully welded membrane water-cooled wall structure, which is made of pipes and flat steel to ensure the tightness of the furnace under any operating conditions. The water-cooled screen of the waste heat boiler is suspended on the steel frame through the upper suspension rod of the upper header. Multiple layers of rigid beams with sufficient strength are arranged from top to bottom on the periphery of the waste heat boiler, so that the furnace has sufficient resistance to external and internal explosions. Necessary observation holes, thermal measurement holes, manholes and soot blowing holes are also arranged on the water-cooled wall.

[0096] A drain valve is installed on the lower header of each heating surface to facilitate regular drainage.

[0097] The feature of the waste heat boiler 9 that it is not blocked is as follows: the salts carried by the flue gas adhere to the membrane wall and the water-cooled screen. At the same time, low-temperature steam and water flow inside the membrane wall and the water-cooled screen. At the contact surface between the salts and the membrane wall and the water-cooled screen, the heat carried by the salts is quickly taken away, thereby forming a brittle film here. As the weight of the salts adhered to the membrane surface increases, the weight also increases, and they will fall off by themselves under the action of gravity. At the same time, multiple steam soot blowers are arranged in the cooling chamber of the waste heat boiler 9. Due to the existence of the brittle film and the blowing, the salts hanging on the wall can be easily blown off. In addition, due to the special structure of the waste heat boiler with a large enough net distance between each heating surface, the salts that have fallen off by themselves before bridging will be blown off, so it can be ensured that the waste heat boiler will not be blocked and the waste heat boiler can be maintained with a high heat transfer efficiency.

[0098] The desalted water enters the deaerator, and is deoxygenated by introducing low-pressure steam into the deaerator. The deoxygenated water is then pumped to the steam drum through the boiler feed water pump. The boiler water in the steam drum enters the heating surface of the waste heat boiler and exchanges heat with the high-temperature flue gas to generate saturated steam, which is then discharged from the steam drum and sent to the steam separator. Part of the steam is sent back to the steam-using equipment in the boundary area through the steam separator, and the rest of the steam is sent to the steam network in the plant through pipelines.

[0099] The steam drum is equipped with a steam-uniform orifice plate, a gap-type steam-water separator, a jet-type water supply distribution pipe and a sewage pipe to improve the steam quality, which can make the water content of boiler steam less than 1%. The liquid level gauge and the balance container interface are arranged on the steam drum. Each interface can be connected to the over-temperature and over-pressure alarm device and interlock, remote water level display device, high and low water level alarm, low water level interlock, etc. Users can arrange the liquid level gauge according to the actual situation to ensure the safe and reliable operation of the boiler.

[0100] The flue gas at the outlet of the waste heat boiler 9 at about 500-550°C enters the quenching tower 12. The glyphosate crystal liquid contains water, and after the quenching spray, a large amount of water will be precipitated after deacidification and cooling. In line with the principle of energy saving and water saving to reduce sewage discharge as much as possible, and considering that high-salt wastewater has no disadvantages to quenching spray, the present invention recycles the high-salt water after deacidification to spray the quenching tower. In order to prevent the high-salt water from wearing the quenching water pump and the like, a quenching circulation pool is set after the deacidification sedimentation tank, so that the deacidified water enters the quenching circulation pool after standing and settling in the sedimentation tank. The quenching spray water comes from the quenching circulation pool. When the system is running, the quenching water pump draws water from the quenching circulation pool to spray the quenching tower, quickly cools the flue gas, and reduces the 500-550°C flue gas to about 180°C within 1s and discharges the quenching tower. A quenching water pipeline is connected above the quenching circulation pool to supplement the insufficient supply of quenching circulating water. The quenching circulating water enters the quenching tower and is completely evaporated. The small amount of salt it carries is precipitated, with part of it falling into the ash hopper at the bottom of the quenching tower and the other part being captured by the bag dust collector.

[0101] A venturi tube is arranged on the flue between the quench tower and the bag filter. The venturi tube is provided with interfaces for activated carbon injection device and slaked lime injection device. The generation of dioxin-like harmful substances is suppressed by injecting activated carbon powder and slaked lime powder into the flue gas. Then the flue gas at about 180°C enters the bag filter. The bag filter adopts a compartment structure for online detection and online replacement of bags, that is, when the bag is damaged, the compartment where the damaged bag is located can be detected online, and the damaged bag can be replaced without stopping the furnace. Some solid salt particles, activated carbon powder and slaked lime powder carried in the flue gas are separated in the bag filter. The ash at the bottom of the bag filter ash hopper is discharged into the fourth water-cooled scraper conveyor 39 and the fifth water-cooled scraper conveyor 40 by means of vibration at regular intervals, and then transported to the third water-cooled scraper conveyor 38 for collection. This part of the salt is mixed with slaked lime and activated carbon powder, which can be sent to the adiabatic incinerator.

[0102] The flue gas coming out of the bag filter enters the deacidification tower, and then the acid gas in the flue gas is removed.

[0103] The present invention adopts sodium method for deacidification. The deacidification tower is made of stainless steel. The deacidification tower is in the form of an empty tower and arranged vertically. A three-layer spray device is arranged inside the deacidification tower, which can make the alkali solution fully contact with the flue gas and improve the deacidification efficiency.

[0104] The flue gas reacts with the sodium hydroxide in the deacidification circulating liquid sprayed by the deacidification spray pump in the deacidification tower to neutralize the acidic gas carried in the flue gas. The deacidification is equipped with three water tanks, namely: sedimentation tank, neutralization tank and clear water tank. The circulating liquid that falls back to the bottom of the deacidification tower after deacidification spraying flows into the sedimentation tank by gravity. It stands in the sedimentation tank for a period of time to precipitate the ash and dust carried in the circulating liquid. Then the clear liquid enters the neutralization tank through the overflow weir. Alkali liquid and clean water are added to the neutralization tank to reconcile the circulating liquid. The reconciled alkali liquid enters the clear water tank through the overflow weir. The alkali liquid in the clear water tank is extracted by the circulating spray pump and sent to the deacidification tower for circulating spraying. When the solution in the sedimentation tank reaches a certain concentration, the deacidification sewage outlet pump is turned on to send the deacidification circulating liquid to the sewage treatment plant. In addition, a quenching circulation pool is set up next to the sedimentation tank. The water after static sedimentation enters the quenching circulation pool through the overflow weir and is used for cooling and spraying the quenching tower. The flue gas temperature after deacidification is about 65℃ and is discharged from the deacidification tower.

[0105] During the deacidification process, the flue gas contacts with a large amount of alkali solution, resulting in a large amount of moisture carried by the flue gas. Direct discharge will cause serious problems such as water in the induced draft fan, equipment vibration, equipment corrosion, and white smoke. Therefore, a two-layer demister is designed on the top of the deacidification tower to remove the moisture carried in the flue gas; in order to further remove the moisture carried in the deacidification flue gas, a cyclone plate demister 16 is provided at the outlet flue of the deacidification tower. The double-layer demisting method can remove the water mist more efficiently.

[0106] Since the glyphosate crystal liquid contains fuel-type nitrogen, a large amount of nitrogen oxides will be produced after high-temperature incineration. In order to ensure ultra-low flue gas emissions, the present invention adopts SCR denitrification. An SCR denitrification device is arranged at the tail of the flue gas treatment system. The SCR denitrification catalyst of this system adopts a low-temperature NOx honeycomb catalyst, and the optimal operating temperature is between 220 and 280°C. Therefore, a flue gas heater is arranged in front of the SCR denitrification device, and the flue gas at about 65°C after deacidification and demisting is heated to 220°C before entering the SCR denitrification device for nitrogen oxide removal. An ammonia spray grid is arranged on the flue connecting the flue gas heater and the SCR denitrification device. 20% ammonia water is sprayed into the flue gas after being atomized by compressed air in the atomizing spray gun, and enters the denitrification device after being fully and evenly mixed with the flue gas, and the NOx reduction reaction is carried out with the catalyst. The SCR denitrification catalyst is used to remove NOx and achieve the purpose of ultra-low nitrogen oxide emissions.

[0107] The temperature of flue gas coming out of the SCR denitration device is about 220℃. Direct emission will waste a lot of heat. In order to save natural gas consumption and reduce operating costs, an air preheater is installed after the denitration device to exchange heat between the combustion air of the adiabatic incinerator and the 220℃ flue gas after denitration. The combustion air and flue gas are countercurrently exchanged in the air preheater. The air is heated to about 170℃ and enters the incinerator for incineration. The flue gas is cooled to about 130℃ and sent into the chimney by the induced draft fan and discharged into the atmosphere.

[0108] Since the molten salt pool at the bottom of the adiabatic incinerator comes out with high-temperature molten sodium chloride salt, a first double-axis cooler 24 and a second double-axis cooler 25 are arranged at the lower part of the adiabatic incinerator to cool the molten salt flowing out of the overflow port, and after cooling, the molten salt becomes solid salt and falls into the first water-cooled scraper conveyor 26; the first water-cooled scraper conveyor 26 delivers solid salts such as sodium chloride to the packaging workshop, and after the salts are crushed by the first crusher, they are cooled again in the first roller slag cooler 27, and the cooled salts are lifted to the hopper of the first baler 29 by the first sealed bucket elevator 28, and the sodium chloride salts are baled at the lower part of the baler through the baling bag. The particles are packaged and packed, and then stored in the workshop; the sodium pyrophosphate salt collected by the ash hoppers of the two cooling chambers of the waste heat boiler enters the third double-axis cooler 30 and the fourth double-axis cooler 31 respectively, and then enters the second water-cooled scraper conveyor 32; the second water-cooled scraper conveyor 32 sends the solid salt to the packaging workshop, and after the salt is crushed by the second crusher, it is cooled again in the second drum slag cooler 33, and the cooled salt particles are lifted by the second sealed bucket elevator 34 to the hopper of the second baler 35, and the sodium pyrophosphate salt particles are packaged and packed at the bottom of the baler through packaging bags, and then stored in the workshop after packaging.

[0109] The salt collected by the bag filter contains activated carbon powder and slaked lime powder, and enters the third water-cooled scraper conveyor 38 through the fourth water-cooled scraper conveyor 39 and the fifth water-cooled scraper conveyor 40. The collected solid salt can be sent to an adiabatic incinerator for incineration to eliminate the activated carbon powder and its dioxins and recover the inorganic salt.

[0110] Since the spray water of the quenching tower is the circulating water after deacidification, the solid salt in the lower ash hopper needs to be collected separately and can be sent to the adiabatic incinerator for incineration together with the solid salt collected by the bag filter.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A glyphosate crystal liquid resource recovery and environmental protection treatment system, characterized in that: It includes an adiabatic incinerator (1), a waste heat boiler (9), a quench tower (12), a bag filter (14), a deacidification tower (15), a cyclone plate demister (16), a flue gas heater (18), an SCR denitrification device (20), an air preheater (21), an induced draft fan (22) and a chimney (23) which are arranged in sequence; The adiabatic incinerator (1) adopts a U-shaped structure, and the bottom connection of the U-shaped structure is provided with an inclination angle of 5°; the bottoms of the adiabatic incinerator (1), the waste heat boiler (9) and the bag filter (14) are respectively provided with salt recovery devices; the salt outlet at the bottom of the U-shaped adiabatic incinerator outputs high-temperature molten sodium chloride salt, and the two cooling chambers of the waste heat boiler output sodium pyrophosphate salt; the incineration temperature of the adiabatic incinerator is 1100-1200°C; A plurality of waste liquid atomizing spray guns (5) are arranged on the furnace top of the adiabatic incinerator (1), and the spray angles of adjacent spray guns of the plurality of waste liquid atomizing spray guns (5) do not interfere with each other and do not touch the furnace wall; Three layers of natural gas burners (3) are arranged on the upper and middle furnace walls of the adiabatic incinerator (1), and the natural gas burners (3) on each layer are arranged in a four-corner cut circle form; The U-shaped rear half of the adiabatic incinerator (1) is provided with three sonic soot blowers (6).

2. The glyphosate crystal liquid resource recovery and environmental protection treatment system according to claim 1, characterized in that: The furnace water-cooled wall of the waste heat boiler (9) adopts a fully welded membrane water-cooled wall structure, and a multi-point steam soot blower is arranged in the cooling chamber of the waste heat boiler (9).

3. The glyphosate crystal liquid resource recovery and environmental protection treatment system according to claim 1, characterized in that: A venturi tube is provided on the flue between the quenching tower (12) and the bag filter (14), and interfaces for an activated carbon injection device and a slaked lime injection device are arranged on the venturi tube.

4. The glyphosate crystal liquid resource recovery and environmental protection treatment system according to claim 1, characterized in that: The bag dust collector (14) adopts a compartment structure for online detection and online bag replacement.

5. The glyphosate crystal liquid resource recovery and environmental protection treatment system according to claim 1, characterized in that: The deacidification tower is in the form of an empty tower and is arranged vertically. A cyclone plate demister (16) is provided on the outlet flue of the deacidification tower (15).

6. The glyphosate crystal liquid resource recovery and environmental protection treatment system according to claim 1, characterized in that: A flue gas heater (18) is arranged in front of the SCR denitration device (20), and an air preheater (21) is arranged behind the SCR denitration device (20).

7. The glyphosate crystal liquid resource recovery and environmental protection treatment system according to claim 1, characterized in that: The salt recovery device, the overflow ports of the two molten salt pools at the bottom of the U-shaped adiabatic incinerator (1), are respectively connected to the first double-axis cooler (24) and the second double-axis cooler (25), and the first double-axis cooler (24) and the second double-axis cooler (25) are respectively connected to the first water-cooled scraper conveyor (26); the two ash hoppers at the bottom of the waste heat boiler (9) are respectively connected to the third double-axis cooler (30) and the fourth double-axis cooler (31), and the third double-axis cooler (30) and the fourth double-axis cooler (31) are respectively connected to the second water-cooled scraper conveyor (32); the lower ash hopper of the bag filter (14) is respectively connected to the fourth water-cooled scraper conveyor (39) and the fifth water-cooled scraper conveyor (40); the fourth water-cooled scraper conveyor (39) and the fifth water-cooled scraper conveyor (40) are respectively connected to the third water-cooled scraper conveyor (38).

Images