Sludge semi-drying and leather solid waste blending combustion system and method

Abstract

The invention relates to the technical field of sludge treatment and resource recycling, and discloses a sludge semi-drying and leather solid waste blending combustion system and method.The sludge semi-drying and leather solid waste blending combustion system comprises a sludge pretreatment unit, a drying unit, a leather processing solid waste pretreatment unit, a blending combustion unit and a pollutant treatment unit; the drying unit is used for drying sludge, the leather processing solid waste pretreatment unit comprises a semi-dry leather solid waste pretreatment unit and a dry leather leftover material pretreatment unit, the leather leftover material mixing unit is connected with the broken leather and dried sludge mixing unit, and the pollutant treatment unit is used for purifying the blending combustion unit. The pollutant treatment unit comprises a particulate matter treatment unit and a desulfurization and denitrification unit which are communicated with each other. According to the invention, cooperative treatment of the sludge and the leather processing solid waste is realized, the energy utilization efficiency is improved, and the treatment cost and environmental pollution are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sludge treatment and resource recovery and utilization, and particularly relates to a sludge semi-drying and leather solid waste co-incineration system and method. Background Art

[0002] With the development of the industrialization process, the generation of industrial solid waste and industrial sewage has increased sharply. As a by-product of sewage treatment, sludge is rich in a large amount of organic matter, pathogens, heavy metals and other pollutants. If not properly disposed of, it is extremely easy to cause pollution to soil, water bodies and the atmosphere. Traditional sludge treatment methods, such as landfilling, incineration, etc., not only occupy a large amount of land resources, but may also cause secondary pollution problems. At the same time, the original landfill of industrial solid waste as the ultimate treatment means has gradually been replaced by incineration; however, in the process of industrial solid waste incineration, there are also problems such as unstable calorific value, harsh incineration furnace inlet conditions, difficult control of pollutant emissions, and difficulty in mixing single sludge incineration with solid waste incineration.

[0003] In order to effectively solve the above problems existing in the process of sludge and industrial solid waste treatment, drying the sludge and co-incinerating it with dry and semi-dry solid wastes such as leather scraps, leather buffing ash, and fleshing residues during leather production has become a very potential solution.

[0004] However, the existing sludge drying and industrial solid waste co-incineration technology still has many deficiencies. For example, the energy consumption of sludge drying is too high, an external heat source is required, the dried sludge is not evenly mixed with leather processing solid waste, resulting in incomplete combustion, unstable calorific value, and excessive pollutant emissions.

[0005] Therefore, those skilled in the art urgently need to develop a sludge semi-drying and leather solid waste co-incineration system and method. Summary of the Invention

[0006] The main purpose of the present invention is to provide a sludge semi-drying and leather solid waste co-incineration system and method. By optimizing the sludge drying process and reasonably designing the crushing and co-incineration processes of sludge and leather processing solid waste, the energy consumption of sludge drying is reduced, the mixing uniformity of sludge and leather processing solid waste is improved, the calorific value is stabilized, full combustion is promoted, pollutant emissions are reduced, thereby reducing the overall treatment cost and improving the resource recovery utilization rate.

[0007] Based on one object of the present invention, the following technical solution is proposed: a sludge semi-drying and leather solid waste co-incineration system, including a sludge pretreatment unit, a drying unit, a leather processing solid waste pretreatment unit, a co-incineration unit, and a pollutant treatment unit; The sludge pretreatment unit is used for sludge pretreatment, and the sludge pretreatment unit includes sludge and a mechanical grille, a sludge slow storage bin, a sludge centrifuge, and a post-dehydration sludge slow storage bin arranged in sequence; The drying unit is used for sludge drying. The drying unit includes a paddle dryer, a dry sludge scraper conveyor I, a dry sludge scraper conveyor II, a dried sludge buffer bin, and a dried sludge buffer bin discharging screw conveyor connected in sequence. The leather processing solid waste pretreatment unit includes a semi-dry leather solid waste pretreatment unit and a dry leather scrap pretreatment unit. The semi-dry leather solid waste pretreatment unit and the dry leather scrap pretreatment unit are respectively connected to the leather scrap mixing unit. The leather scrap mixing unit and the drying unit are respectively connected to the crushed leather and dried sludge mixing unit. The co-firing unit is connected to the crushed leather and dried sludge mixing unit. The pollutant treatment unit is used for purifying the co-firing unit. The pollutant treatment unit includes a particulate matter treatment unit and a desulfurization and denitrification unit that are interconnected.

[0008] Preferably, the mechanical grille is arranged on the left side of the sludge buffer storage bin. The sludge buffer storage bin is connected to a sludge centrifugal dewatering machine through a sludge transfer pump. The discharging end of the sludge centrifugal dewatering machine is provided with a dewatered sludge screw conveyor. The side of the dewatered sludge screw conveyor away from the sludge centrifugal dewatering machine is located above the dewatered sludge buffer storage bin. The discharging port of the dewatered sludge buffer storage bin has two paths. One path of the discharging port is connected to the drying unit through a dewatered sludge transfer pump and a sludge to dryer plunger pump in sequence. The other path of the discharging port is directly connected to the leather processing solid waste pretreatment unit through a dewatered sludge transfer pump and a sludge to incinerator front transfer pump in sequence.

[0009] Preferably, the sludge to dryer plunger pump is connected to the paddle dryer. A cyclone dust collector and a carrier gas condensation tower are connected to the top of the paddle dryer. The carrier gas condensation tower is connected to a demister and a carrier gas blower in sequence. The carrier gas blower transports the gas to the co-firing unit. A bin top dust collector is provided on the top of the dried sludge buffer bin.

[0010] Preferably, the semi-dry leather solid waste pretreatment unit includes meat residue semi-dry materials and a meat residue pit, a semi-dry material grab bucket machine, a semi-dry material feeder, a chain conveyor, a semi-dry meat residue feeding conveyor, a semi-dry meat residue meat grinder, a meat grinder discharging belt, and a pear-shaped distributor arranged in sequence. The dry leather scrap pretreatment unit includes dry leather scraps and a feeding chain conveyor, a single-shaft crusher, and a crusher discharging belt arranged in sequence. [[ID=XX]]The leather scrap mixing unit includes a crushed leather buffer pit, a crushed leather grab bucket machine, a crushed leather buffer bin, and a crushed leather buffer bin discharging screw arranged in sequence. The crushed leather and dried sludge mixing unit includes a crushed leather mixing belt, a mixer, a mixer discharge screw, a bucket elevator, a mixed material buffer bin, a quantitative weight valve, a buffer bin in front of the furnace, and an incinerator feed screw arranged in sequence. The secondary feed port of the incinerator feed screw is connected to the discharge end of the sludge conveying pump before going to the incinerator.

[0011] Preferably, the co-incineration unit includes a bubbling fluidized bed incinerator. The exhaust port of the bubbling fluidized bed incinerator is connected to a waste heat boiler. The output end of the incinerator feed screw is connected to the feed end of the bubbling fluidized bed incinerator. The gas outlet end of the waste heat boiler is connected to the waste heat steam to dryer. The waste heat steam to dryer is connected to a paddle dryer. The bottom of the waste heat boiler is sequentially connected with a discharger and a ash cooling screw conveyor. The ash cooling screw conveyor is connected to an ash bin.

[0012] Preferably, a quartz sand bin is arranged beside the bubbling fluidized bed incinerator. The quartz sand bin conveys quartz sand to the bubbling fluidized bed incinerator through a quartz sand conveying screw. The bottom of the bubbling fluidized bed incinerator is sequentially provided with a knife gate valve and a cold sand conveyor.

[0013] Preferably, the particulate matter treatment unit includes an electrostatic precipitator. The left end of the electrostatic precipitator is connected to the waste heat boiler. The right end of the electrostatic precipitator is sequentially connected with an activated carbon feeder and a bag filter. The bottom of the electrostatic precipitator is connected to an ash discharge device through a screw metering feeder. The bottom of the bag filter is connected to a fly ash discharge device through a screw metering feeder.

[0014] Preferably, the desulfurization and denitrification unit includes a first-stage absorption and deacidification tower and a second-stage absorption and deacidification tower that are interconnected. A first-stage lime liquid atomizing sprayer and a second-stage lime liquid atomizing sprayer are respectively arranged inside the first-stage absorption and deacidification tower and the second-stage absorption and deacidification tower. The first-stage lime liquid atomizing sprayer and the second-stage lime liquid atomizing sprayer are respectively connected to the limestone slurry through a first-stage lime liquid circulation pump and a second-stage lime liquid circulation pump. The bottom of the second-stage absorption and deacidification tower is connected to a waste gypsum to dewatering machine. The top of the second-stage absorption and deacidification tower is connected to a wet electrostatic precipitator and a flue gas heater. The flue gas heater is connected to an SCR denitrification system. A chimney is arranged beside the SCR denitrification system.

[0015] Based on another object of the present invention, a method for semi-drying sludge and co-incinerating leather solid waste is proposed, including the following steps: S1. Sludge pretreatment: The sludge is lifted by a sludge pump, filtered through a mechanical grille and then enters the sludge buffer storage bin. At this time, the moisture content of the sludge is about %. The sludge is transported to a sludge centrifugal dewatering machine by a sludge transfer pump. After centrifugal dewatering, the moisture content of the sludge reaches below %, and is sent to the dewatered sludge buffer storage bin through a dewatered sludge screw conveyor, meeting the subsequent drying conditions. S2. Drying: Part of the sludge in the dewatered sludge buffer storage bin is directly sent to the co-firing unit, and the other part is sent to a paddle dryer through a sludge transfer pump before the incinerator to complete the sludge drying process. The dried sludge is sent to the dried sludge buffer bin through a dry sludge scraper conveyor 1 and a dry sludge scraper conveyor 2 in sequence. The dry sludge inside the dried sludge buffer bin is sent to the leather processing solid waste pretreatment unit through a dried sludge buffer bin discharge screw conveyor. S3. Leather processing solid waste pretreatment: The collected semi-dry meat residue materials are transported to the meat residue pit, fed into the semi-dry material feeder by a semi-dry material grabber, and the semi-dry meat residue is sent through a chain conveyor and a semi-dry meat residue feeding conveyor to a semi-dry meat residue mincer. After being minced into a diameter of millimeters, it is sent into the leather waste buffer pit through a mincer discharge belt and a pear-shaped distributor. Dry leather trimmings are collected in the workshop and transported to the waste storage room, and then sent to a single-shaft crusher through a feeding chain conveyor. After being crushed into a suitable size of less than millimeters, it is sent to the leather waste buffer pit through a crusher discharge belt. The semi-dry leather solid waste and dry leather trimmings are simply mixed by a crushed leather grabber and sent to the crushed leather buffer bin, and then sent to the crushed leather mixing belt through a crushed leather buffer bin discharge screw to enter the mixer simultaneously with the dried sludge. It is stirred in the mixer at a speed of 20 revolutions per minute for minutes, and after being fully mixed, it is sent to a hoist and through a mixer discharge screw, and enters the mixed material buffer bin for storage. It is quantitatively distributed to the buffer bin in front of the furnace through a quantitative weight hammer valve, and then the mixed material and the wet sludge transported by the sludge transfer pump before the incinerator are sent into the co-firing unit through an incinerator feeding screw. S4. Co-firing: The materials after leather processing solid waste pretreatment are incinerated by a bubbling fluidized bed incinerator. The hot gas after combustion is transported to the paddle dryer through the waste heat steam to the dryer, and the heat energy is used for sludge drying. The ash slag is collected through a waste heat boiler. By controlling the slide valve and the cold sand conveyor, make up the material to the quartz sand bin by external transportation. S5. Pollutant treatment: The flue gas enters an electrostatic precipitator. The particulate matter captured by the static electricity is sent out of the electrostatic precipitator under the action of an ash slag discharger and finally sent to the ash slag for comprehensive utilization. After the flue gas passes through the electrostatic precipitation, it enters a bag filter through an activated carbon feeder. The filtered particulate matter is sent out of the bag filter through a fly ash discharger and then undergoes fly ash hazardous treatment. After the flue gas is filtered by the bag filter, it enters the primary absorption and deacidification tower, where desulfurization is carried out through the primary lime solution atomizing sprayer. Then it enters the secondary absorption and deacidification tower, and after secondary desulfurization through the secondary lime solution atomizing sprayer, the flue gas enters the wet electrostatic precipitator to further remove particulate matter. After that, it is heated to 150 °C by the flue gas heater and the SCR denitration system is added. After denitration, the treated flue gas is sent into the chimney by the induced draft fan for up-to-standard discharge.

[0016] Furthermore, in step S3, the sludge and the crushed leather solid waste are in a ratio of 6:2; in step S4, the temperature in the incinerator is controlled between 850 °C and 900 °C, and the residence time is not less than 2 seconds to ensure the full combustion of the mixed materials.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: In the present invention, it aims to realize the co-treatment of sludge and leather processing solid waste, improve the energy utilization efficiency, and reduce the treatment cost and environmental pollution.

[0018] 1. Energy consumption reduction: The waste heat generated by the incineration of leather processing solid waste is used to dry the sludge, reducing the consumption of external energy and the cost of sludge drying; using part of the (adjusted according to the actual incineration conditions) undried sludge directly entering the incinerator for incineration not only reduces the drying cost but also can adjust the feeding amount of wet sludge into the furnace according to the incineration conditions of the incinerator, effectively solving the problem of unstable operation of the incinerator. 2. Combustion efficiency improvement: Through the drying of sludge, direct incineration of part of the wet sludge into the furnace, crushing pretreatment of leather processing solid waste, as well as the mixing method of dry and wet materials and reasonable co-incineration ratio, the mixed materials burn more fully, improving the energy utilization efficiency. 3. Pollutant emission reduction: Advanced combustion control systems and flue gas purification devices effectively reduce the emissions of pollutants such as dioxins, nitrogen oxides, and sulfur dioxide, reducing environmental pollution. 4. Resource recovery and utilization: The ash and slag generated by incineration are recycled, reducing the generation of waste and realizing the circular utilization of resources.

[0019] 5. Environmental benefits: After the incineration of sludge and solid waste, the goals of resourceization of solid waste (the calorific value of sludge and solid waste reaches 6000 - 10000 kJ / kg, 10000 - 15000 kJ / kg (dry basis), and a large amount of steam is generated through incineration to meet the subsequent sludge drying requirements); harmlessness (pathogenic bacteria, parasite eggs, and viruses are killed through high-temperature incineration treatment, eliminating the threat to the environment and human health); reduction (the volume of solid waste can be reduced to one-tenth of the original volume after incineration treatment, facilitating transportation and subsequent disposal); stabilization (by using the incineration method, the organic matter and putrefactive substances in the solid waste are fully utilized, reducing the generation of malodorous gases and gaseous pollutants) are achieved. Description of the Drawings

[0020] Figure 1 is the overall structural schematic diagram of the present invention; Figure 2 is the structural schematic diagram of the sludge pretreatment unit of the present invention; Figure 3 is the structural schematic diagram of the drying unit of the present invention; Figure 4 is the structural schematic diagram of the semi-dry leather solid waste pretreatment unit of the present invention; Figure 5 is the structural schematic diagram of the dry leather scraps pretreatment unit of the present invention; Figure 6 is the structural schematic diagram of the leather scraps mixing unit of the present invention; Figure 7 is the structural schematic diagram of the crushed leather and dried sludge mixing unit of the present invention; Figure 8 is the structural schematic diagram of the co-firing unit of the present invention; Figure 9 is the structural schematic diagram of the particulate matter treatment unit of the present invention; Figure 10 is the structural schematic diagram of the desulfurization and denitrification unit of the present invention. Detailed implementation manners

[0021] The present invention will be clearly described below in conjunction with the accompanying drawings in the embodiments of the present invention and specific embodiments. The description here is only used to explain the present invention and does not limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts, any modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the present invention.

[0022] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Embodiment 1 Please refer to Figures 1 - 10 , the present invention provides a sludge semi-drying and leather solid waste co-incineration system, including a sludge pretreatment unit, a drying unit, a leather processing solid waste pretreatment unit, a co-incineration unit, and a pollutant treatment unit; The sludge pretreatment unit is used for sludge pretreatment. The sludge pretreatment unit includes sludge 01 and a mechanical grille 02, a sludge slow storage bin 03, a sludge centrifuge 05, and a dewatered sludge slow storage bin 06 arranged in sequence; The drying unit is used for sludge drying. The drying unit includes a paddle dryer 010, a dry sludge scraper conveyor 011, a dry sludge scraper conveyor 012, a dried sludge buffer bin 013, and a dried sludge buffer bin discharge screw conveyor 014 connected in sequence; The leather processing solid waste pretreatment unit includes a semi-dry leather solid waste pretreatment unit and a dry leather scrap pretreatment unit. The semi-dry leather solid waste pretreatment unit and the dry leather scrap pretreatment unit are respectively connected to a leather scrap mixing unit, and the leather scrap mixing unit and the drying unit are respectively connected to a crushed leather and dried sludge mixing unit; The co-incineration unit is connected to the crushed leather and dried sludge mixing unit, and the pollutant treatment unit is used for purifying the co-incineration unit. The pollutant treatment unit includes a particulate matter treatment unit and a desulfurization and denitrification unit that are interconnected.

[0025] Further, the mechanical grille 02 is arranged on the left side of the sludge slow storage bin 03. The sludge slow storage bin 03 is connected to the sludge centrifuge 05 through a sludge transfer pump 04. The discharge end of the sludge centrifuge 05 is provided with a dewatered sludge screw conveyor, and the side of the dewatered sludge screw conveyor away from the sludge centrifuge 05 is located above the dewatered sludge slow storage bin 06; The discharge port of the dewatered sludge slow storage bin 06 has two paths. One path of the discharge port is connected to the drying unit through a dewatered sludge transfer pump 07 and a sludge to dryer shaft plug pump 09 in sequence, and the other path of the discharge port is directly connected to the leather processing solid waste pretreatment unit through a dewatered sludge transfer pump 07 and a sludge to incinerator front transfer pump 08 in sequence.

[0026] The concentrated sludge with a water content of 97% from the sewage treatment plant is transported by a sludge pump, filtered by a grille machine, and then enters the sludge dewatering system. After being dewatered by a centrifuge, the sludge with a water content of 80% enters the storage bin and is transported to the sludge paddle-type sludge drying device by a sludge pump. After drying, the water content of the sludge is below 40%.

[0027] Furthermore, the sludge goes to the plunger pump 09 of the dryer and is connected to the paddle dryer 010. A cyclone dust collector and a carrier gas condensation tower are connected to the top of the paddle dryer 010. The carrier gas condensation tower is successively connected with a demister and a carrier gas fan. The carrier gas fan transports the gas to the co-firing unit. A dust collector is provided on the top of the dry sludge buffer bin 013.

[0028] The dryer uses the waste heat steam generated by the incineration of sludge and leather processing solid waste to dry the sludge. Steam is introduced into the paddles in the dryer and can achieve stirring and propulsion, making the sludge evenly heated during the drying process and preventing the sludge from caking at the same time.

[0029] Using the waste heat saturated steam generated by the incineration of leather processing solid waste, by heating the paddle blades in the dryer, at this time the sludge is in full contact with the paddle blades for heat exchange, and the sludge is dried, so that the water content of the sludge is reduced to below 40%. The dryer uses steam as the heating medium, and a rotary joint for introducing and discharging the heat medium is installed at the shaft end. The sludge is turned and stirred by the rotation of the paddles, continuously updating the heating interface, contacting the body and the paddles, and being fully heated, so that the surface moisture contained in the material evaporates. The dried sludge is transported in a spiral trajectory along with the rotation of the paddle shaft towards the discharge port, and continues to be stirred during the transportation, so that the water exuded from the sludge continues to evaporate. Finally, the dried sludge is pushed out of the dryer by a screw conveyor.

[0030] Furthermore, the semi-dry leather solid waste pretreatment unit includes meat residue semi-dry materials 11 and a meat residue pit 12, a semi-dry material grabber 13, a semi-dry material feeder 14, a chain conveyor 15, a semi-dry meat residue feeding conveyor 16, a semi-dry meat residue mincer 17, a mincer discharge belt 18 and a pear-shaped distributor 19 arranged in sequence; The dry leather scraps pretreatment unit includes dry leather scraps 21 and a feeding chain conveyor 22, a single-shaft crusher 23 and a crusher discharge belt 24 arranged in sequence; The leather scraps mixing unit includes a crushed leather buffer pit 31, a crushed leather grabber 32, a crushed leather buffer bin 33 and a crushed leather buffer bin discharge screw 34 arranged in sequence; The crushed leather and dried sludge mixing unit includes a crushed leather mixing belt 41, a mixer 42, a mixer discharge screw 43, a hoist 44, a mixed material buffer bin 45, a quantitative weight valve 46, a furnace front buffer bin 47 and an incinerator feeding screw 48 arranged in sequence. The secondary feeding port of the incinerator feeding screw 48 is connected to the discharge end of the sludge pump 08 before going to the incinerator.

[0031] Leather processing solid waste consists of dry leather scraps and semi-dry leather scraps. The scraps generated by leather production are collected through the production workshop and sent to their respective storage rooms; the dry leather scraps are sent to the crusher by a conveyor belt and crushed into particles below 3mm, and the semi-dry leather scraps are grabbed by a grab crane and transported to a meat grinder, which grinds the wet leather scraps into 2mm particles; after the leather solid waste is crushed into a suitable size after crushing pretreatment, it is stored in a leather scrap temporary storage pool for subsequent co-incineration with the dried sludge.

[0032] The dried sludge is transported via a conveyor belt and fed into a mixer with the crushed leather solid waste via a grab elevator for thorough mixing. To reduce sludge drying costs, adjust the calorific value for incineration, and stabilize the moisture content before entering the incinerator, the present invention allows some undried wet sludge with an 80% moisture content to be directly fed into the front end of the incinerator, where it is incinerated simultaneously with other dried sludge and crushed leather scraps. This adjusts the calorific value and moisture content of the solids entering the incinerator, ensuring the incinerator remains in a stable operating state. The mixed solid waste (dried sludge and crushed leather solid waste) is then transported via a conveyor belt to a screw conveyor in front of the incinerator. The screw conveyor then feeds the solid waste into the incinerator.

[0033] Furthermore, the co-firing unit includes a bubbling circulating fluidized bed incinerator 51, the exhaust port of the bubbling circulating fluidized bed incinerator 51 is connected to the waste heat boiler 52, the output end of the incinerator feed screw 48 is connected to the feed end of the bubbling circulating fluidized bed incinerator 51, the air outlet end of the waste heat boiler 52 is connected to the waste heat steam de-dryer 53, the waste heat steam de-dryer 53 is connected to the paddle dryer 010, and the bottom of the waste heat boiler 52 is connected in sequence with a discharger 54 and an ash cooling screw conveyor 55, and the ash cooling screw conveyor 55 is connected to the ash collection bin 56.

[0034] Furthermore, a quartz sand bin is provided on the side of the bubbling circulating fluidized bed incinerator 51, and the quartz sand bin transports quartz sand to the bubbling circulating fluidized bed incinerator 51 through a quartz sand conveying screw. A gate valve and a cold sand conveyor are provided at the bottom of the bubbling circulating fluidized bed incinerator 51 in sequence.

[0035] The amount of undried wet sludge fed into the incinerator is adjusted based on the incinerator's operating conditions and the temperature and humidity inside the incinerator to meet the incinerator's combustion and tail gas emission treatment requirements. The incinerator uses a bubbling circulating fluidized bed boiler equipped with an advanced combustion condition collection system. This system can adjust combustion parameters in real time based on the calorific value of the mixture and the combustion conditions, ensuring a stable and sufficient combustion process.

[0036] The co-combustion system is an important part of the present invention. Ordinary co-combustion is difficult to achieve economical and effective results. The present invention uses dried sludge and crushed leather solid waste in a ratio of 6:2, stirred at 20 rpm in a mixing mixer for 15 minutes. After thorough mixing, it is sent to a bucket conveyor through a conveyor belt. At the same time, the sludge with a moisture content of 80% after centrifuge dehydration is mixed with the mixed solid waste in proportion according to actual operating conditions and then fed into the incinerator for combustion. The temperature in the incinerator is controlled between 850℃ and 900℃, and the residence time is not less than 2 seconds to ensure that the mixed material is fully burned.

[0037] Furthermore, the particulate matter treatment unit includes an electrostatic precipitator 61, the left end of the electrostatic precipitator 61 is connected to the waste heat boiler 52, the right end of the electrostatic precipitator 61 is connected to an activated carbon feeder 64 and a bag dust collector 65 in sequence, the bottom of the electrostatic precipitator 61 is connected to an ash discharger 62 through a spiral metering feeder, and the bottom of the bag dust collector 65 is connected to a fly ash discharger 67 through a spiral metering feeder.

[0038] Furthermore, the desulfurization and denitrification unit includes a primary absorption and deacidification tower 661 and a secondary absorption and deacidification tower 664 that are interconnected. The primary absorption and deacidification tower 661 and the secondary absorption and deacidification tower 664 are respectively provided with a primary lime liquid atomizing sprayer 662 and a secondary lime liquid atomizing sprayer 665. The primary lime liquid atomizing sprayer 662 and the secondary lime liquid atomizing sprayer 665 are respectively connected to the limestone slurry 667 through a primary lime liquid circulation pump 663 and a secondary lime liquid circulation pump 666. The bottom of the secondary absorption and deacidification tower 664 is connected to a waste gypsum dehydrator 668, and the top of the secondary absorption and deacidification tower 664 is connected to a wet electrostatic precipitator 669 and a flue gas heater 671. The flue gas heater 671 is connected to an SCR denitrification system 672, and a chimney is provided next to the SCR denitrification system 672.

[0039] The flue gas purification device is used to remove pollutants such as particulate matter, dioxins, nitrogen oxides, and sulfur dioxide generated during the incineration process to ensure that the flue gas meets emission standards. The ash treatment device collects, treats, and recycles the ash generated by incineration.

[0040] Upon entering the electrostatic precipitator, the dust-laden gas charges the dust. Under the influence of the high electric field, the positively and negatively charged dust particles are adsorbed onto the corona electrode and precipitation electrode surfaces, respectively, with opposite polarities, achieving dust-gas separation. After electrostatic precipitator removal, the flue gas passes through activated carbon in the flue reactor, where it reacts with the activated carbon to remove heavy metals and dioxins / furans. The flue gas then enters the 65 bag filter, where the filter cake also acts as a reactor, further reacting and adsorbing heavy metals in the flue gas with the activated carbon.

[0041] The flue gas enters the downstream primary absorption tower after passing through the bag filter. The desulfurization absorption tower adopts a double-tower double-cycle process. More than 90% of SO2 is removed in the primary absorption tower, and the remaining small amount of SO2 is removed in the secondary absorption tower. In the absorption tower, the reverse flow of the flue gas and the limestone / gypsum suspension droplets occurs. SO2 and SO3 react with the limestone in the suspension to form calcium sulfite, which is oxidized by the oxidation air in the absorption tower slurry pool (the lower part of the absorption tower) to calcium sulfate, and the supersaturated solution crystallizes into gypsum.

[0042] The flue gas at the top of the secondary absorption tower enters the wet electrostatic precipitator after passing through the absorption tower. The wet electrostatic precipitator is arranged in a tubular form at the top of the secondary absorption tower. The wet flue gas from the secondary absorption tower enters from the lower part of the wet electrostatic precipitator, and the purified flue gas is discharged from the side of the wet electrostatic precipitator.

[0043] The wet electrostatic precipitation system mainly includes a flushing water system, a sealed air system, a cathode system, an anode system, and an electric control system, etc. After the flue gas enters the denitrification process, the process adopts the selective catalytic reduction denitrification (SCR) process, with 25% ammonia water as the reducing agent; the flue gas flows vertically towards the catalyst, and the ammonia water is vaporized and injected into the flue in front of the catalyst as the reducing agent. The clean flue gas coming out of the SCR reaction tower is sent into a 60-meter-high flue for discharge by a 5 induced draft fan. After being treated by the flue gas purification device, it meets the discharge standards, and the generated ash and slag are collected, treated, and recycled through the ash and slag treatment device.

[0044] Example 2 Based on the theory of Example 1, this scheme has carried out system construction and actual operation, as follows: (I) System construction According to the treatment scale and site conditions, through experiments and on-site reasonable selection and installation of equipment for the sludge pretreatment unit, drying unit, leather processing solid waste pretreatment unit, co-firing unit, incineration, and pollutant treatment unit. Ensure that the connecting pipes and conveying devices between each equipment are well sealed and operate smoothly. After installation, the entire system is debugged to check whether the operating parameters of each equipment are normal and whether the coordinated work between each unit is coordinated. (II) Actual operation 1. Sludge pretreatment: The sludge generated by the sewage treatment plant is pumped from the sewage treatment plant at a fixed time every day. After the hair in the sludge is filtered through the mechanical grille, the sludge enters the sludge storage bin. At this time, the moisture content of the sludge is 97%; the sludge is transported to the centrifuge by the sludge transfer pump. After centrifugal dehydration, the moisture content of the sludge reaches below 80% and is sent to the sludge buffer bin to meet the subsequent drying conditions; after passing through the buffer bin, the sludge is respectively sent to the sludge dryer by the sludge pump for part of the sludge, and the other part is directly sent to the incinerator according to the incineration conditions by the sludge pump.

[0045] 2. Sludge drying: Monitor the waste heat generation of the sludge and the leather solid waste incinerator in real time. The saturated steam of the waste heat boiler and the dewatered wet sludge enter the paddle dryer and come into full contact with the sludge in the dryer. Heat exchange occurs between the sludge and the paddles, and the moisture of the sludge is evaporated through the heat dissipation of the paddles. The sludge is dried and gradually pushed out of the dryer by the dryer paddles, completing the sludge drying process. The dried sludge is sent into the dried sludge buffer bin through the dry sludge scraper conveyor and the dry sludge scraper conveyor. After passing through the buffer bin, the dried sludge is sent into the broken leather belt and mixed with the broken leather by the dried sludge screw conveyor. The rotation speed of the paddle stirring in the dryer and the steam flow can be adjusted according to the moisture content of the sludge, the sludge feeding amount, and the drying effect.

[0046] 3. Pretreatment of leather processing solid waste: (1) Pretreatment of semi-dry leather meat residue: The collected semi-dry leather solid waste is transported to the storage pit for semi-dry leather of meat residue type, and the semi-dry leather meat residue is sent into the feeder by the grab hoist. After passing through the chain conveyor, the semi-dry meat residue is sent into the meat grinder by the belt conveyor. After the meat grinder grinds the semi-dry meat residue into a diameter of 2 mm, it is sent into the leather broken waste buffer pit through the discharge belt and the pear-shaped distributor. (2) The dry leather scraps of 21 are collected and transported to the waste storage room by the workshop, and the dry leather solid waste is sent to the single-shaft crusher by the chain conveyor. After being crushed into a suitable size of less than 3 mm, it is sent into the leather broken waste buffer pit through the discharge belt.

[0047] 4. Mixing: In order to mix the broken semi-dry and dry leather scraps evenly, after the leather waste crushed by the meat grinder and the crusher are sent into the leather broken waste buffer pit respectively, they are simply mixed by the grab hoist and then sent to the leather waste buffer bin, and then sent to the leather waste belt through the discharge screw of the leather waste buffer bin and enter the mixer at the same time as the dried sludge.

[0048] 5. Mixing: After pretreatment such as sludge drying and leather scrap crushing, various material wastes enter the mixer at the same time through the leather waste belt and the discharge screw of the dried sludge buffer bin according to the calorific value conditions required for incineration. The sludge and the broken leather solid waste are mixed in a ratio of 6:2 and stirred in the mixing blender at a speed of 20 revolutions per minute for 15 minutes. After being fully mixed, they are sent to the bucket elevator through the discharge screw of the mixer. In order to meet the continuity and stability of incineration, the mixed waste enters the mixed material buffer bin. After being stored in the buffer bin, the waste is quantitatively distributed to the buffer bin in front of the furnace through the quantitative weight hammer valve, and then sent into the incinerator through the in-furnace bypass screw feeder to ensure that there is sufficient material for the incinerator to burn. The mixed waste is sent into the incinerator together with the wet sludge through the feeding screws of 4 incinerators according to the incineration conditions of the incinerator.

[0049] 6. Incineration: Through tests and calorific value tests on leather scraps, sludge with a moisture content of 40% after drying, and sludge with a moisture content of 80% without drying, it is obtained that the moisture content of the crushed leather scraps is 25% and the calorific value is 3,500 kcal; the moisture content of the dried sludge is 40% and the calorific value is 1,200 kcal; the moisture content of the undried sludge is 80% and the calorific value is 400 kcal. According to the self-sustaining combustion conditions and requirements of the bubbling fluidized bed incinerator, the incinerator needs 1,800 kcal to achieve self-sustaining combustion. According to the monitoring of the calorific value and moisture of various materials, a ratio of (6:2) is formulated, such as 60% of the dried sludge and 20% of the crushed leather solid waste, and they are fully mixed in a mixing blender; the sludge with a moisture content of 80% is transported to the incinerator through a piston pump before the solid waste enters the furnace. According to the combustion conditions in the incinerator, the parameters of the combustion control system and the moisture content and calorific value of the mixed fuel entering the furnace are adjusted in real time to ensure a stable and sufficient combustion process.

[0050] 7. Treatment of flue gas pollutants: The flue gas and ash generated during the incineration process are monitored in real time to ensure the normal operation of the flue gas purification device and the ash treatment device, and to achieve the up-to-standard discharge of pollutants and the resource utilization of ash. According to the flue gas treatment process flow, the flue gas treatment is divided into two parts: particulate matter treatment and desulfurization and denitrification treatment. After treatment, it meets the waste incineration emission standard "Pollution Control Standard for Municipal Solid Waste Incineration" (GB18480 - 2014).

[0051] According to the particulate matter treatment, after the flue gas takes away heat through the waste heat boiler to generate steam for sludge drying; the flue gas enters the electrostatic precipitator. Electrostatic precipitation is to separate the dust-containing gas by electricity when it passes through a high-voltage electrostatic field. After the particles combine with negative ions and carry negative charges, they tend to discharge on the anode surface and deposit, thus achieving the dust removal effect; the particulate matter captured by the electrostatic precipitator is sent out of the electrostatic precipitator under the action of the unloader and finally goes for comprehensive utilization.

[0052] After the flue gas passes through the electrostatic precipitator, it enters the bag filter through the activated carbon metering feeder. The bag filter mainly uses filter cloth filter bags to pass the dust-containing gas through the filter bags. The dust particles are intercepted due to the collision with the filter cloth fibers by inertial force, and the fine particles are adsorbed by the fibers through the diffusion effect. Through the activated carbon injection system, activated carbon is injected into the bag filter. Activated carbon has the function of adsorbing particulate matter and heavy metals; the activated carbon particles form a dense filter screen through the fiber layer on the surface of the filter bag, and the capture efficiency of particles can reach 99.99%. The filtered particulate matter is sent out of the bag filter through the unloader and then disposed of according to hazardous waste. After the flue gas is filtered by the bag filter, it enters the first-stage desulfurization absorption tower. The desulfurization tower adopts the flue gas lime-gypsum method, and the desulfurization process includes absorption, oxidation, and crystallization steps; the flue gas passes through the spraying and physical-chemical system in the absorption tower to fully contact the physical-chemically treated lime solution with the flue gas. Sulfur dioxide in the flue gas reacts with calcium oxide in the lime to form calcium sulfide, and calcium sulfide then reacts in the high school society to form calcium sulfate and regenerated calcium oxide. The final gypsum is subjected to crystallization separation for comprehensive utilization; in order to improve the desulfurization efficiency and reduce the treatment cost, the absorption tower is equipped with a lime milk circulation pump for circulation, and lime milk is supplemented when the pH value is lower than 6. After the flue gas passes through the first-stage absorption and deacidification tower, in order to meet the emission requirements, the flue gas enters the second-stage absorption and deacidification tower. The working principle of the second-stage absorption tower is the same as that of the first stage. The lime milk passes through the circulation pump and the atomization system to improve the absorption and desulfurization effect, and the final gypsum is subjected to crystallization separation for comprehensive utilization. After the first-stage and second-stage absorption and deacidification, the flue gas enters the wet electrostatic precipitator to further remove particulate matter; wet electrostatic precipitation uses electrostatic force to capture dust in the dust-containing gas. When the dust-containing gas passes through the high-voltage electrostatic field, the dust particles in the gas will be charged, and under the action of the electric field force, these charged particles will move towards the electrode and deposit on the electrode, thus realizing the capture of dust. After passing through the wet electrostatic precipitator, the flue gas enters the SCR denitration system. In order to improve the denitration efficiency of the flue gas, the flue gas first passes through the flue gas reheater. The flue gas is heated to 150°C by steam and ammonia water is added. After meeting the denitration effect, it enters the SCR denitration system. The SCR denitration system mainly includes an ammonia addition system. Liquid ammonia is sent to the liquid ammonia storage tank through the unloading compressor and then evaporated into ammonia gas in the evaporation tank; after the ammonia gas is mixed with air, it enters the SCR reactor through the distribution guide valve for reaction. There is a catalyst layer in the reactor, and the reaction proceeds efficiently under the action of the catalyst, and the denitration efficiency can reach 80-90%. After the flue gas is denitrified, the induced draft fan is used to send the treated flue gas into the chimney for discharge up to standard.

[0053] (3) Effect verification After the system has been running for a period of time, indicators such as the energy consumption of sludge drying, the mixing uniformity of leather processing solid waste and sludge, the combustion efficiency, and pollutant emissions are detected and analyzed. By comparing with the traditional treatment method, the superiority of the system and method of the present invention is verified.

[0054] Example 3 The present invention further provides a method for incinerating semi-dried sludge and leather solid waste, comprising the semi-dried sludge and leather solid waste incineration system of the above embodiment, and further comprising the following steps: S1. Sludge pretreatment: Sludge 01 is lifted by a sludge pump, filtered by a mechanical screen 02, and then enters the sludge buffer storage bin 03. At this time, the sludge moisture content is about 97%. The sludge 01 is transported to the sludge centrifugal dewatering machine 05 by a sludge conveying pump 04. After centrifugal dehydration, the sludge moisture content reaches below 80%. The sludge is then conveyed to the dehydrated sludge buffer storage bin 06 by a dehydrated sludge screw conveyor to meet the subsequent drying conditions. S2, drying: After dehydration, part of the sludge 01 in the sludge buffer storage bin 06 is directly sent to the blending unit, and the other part is sent to the paddle dryer 010 through the sludge pre-incinerator delivery pump 08 to complete the sludge 01 drying process. After drying, the sludge 01 passes through the dry sludge scraper conveyor 011 and the dry sludge scraper conveyor 012 in turn and is sent to the dried sludge buffer bin 013. The dry sludge in the dried sludge buffer bin 013 is sent to the leather processing solid waste pretreatment unit through the dried sludge buffer bin outlet screw conveyor 014; S3. Pretreatment of leather processing solid waste: The collected meat residue semi-dry materials 11 are transported to the meat residue material pit 12, and then sent to the semi-dry material feeder 14 through the semi-dry material grabber 13. The semi-dry meat residue is then passed through the semi-dry meat residue grinder 17 via the chain conveyor 15 and the semi-dry meat residue feeding conveyor 16. After being minced into 2 mm diameter, the semi-dry meat residue is sent to the leather crushing waste buffer pit 31 via the meat grinder discharge belt 18 and the pear-type distributor 19; The dry leather scraps 21 are collected and transported to the waste storage room through the workshop, and then sent to the single-shaft crusher 23 through the feeding chain conveyor 22. After being crushed into a suitable size of less than 3 mm, they are sent to the leather crushing waste buffer pit 31 through the crusher discharge belt 24; The semi-dry leather solid waste and dry leather scraps are simply mixed by the crushed leather grabber 32 and sent to the crushed leather buffer bin 33. Then, they are sent to the crushed leather mixing belt 41 through the crushed leather buffer bin discharge screw 34 and enter the mixer 42 at the same time as the dried sludge 01. They are stirred at a speed of 20 rpm for 15 minutes in the mixer 42. After being fully mixed, they are sent to the lifting bucket 44 through the mixer discharge screw 43 and enter the mixed material buffer bin 45 for storage. They are quantitatively distributed to the furnace buffer bin 47 through the quantitative hammer valve 46, and then sent to the mixed material and the wet sludge delivered by the sludge delivery pump 08 in front of the incinerator through the incinerator feed screw 48 into the co-incineration unit; S4. Co-combustion: The materials after the pretreatment of leather processing solid waste are incinerated by a bubbling fluidized bed incinerator 51. The hot gas after combustion is transported to a paddle dryer 010 through a waste heat steam dryer 53, and the heat energy is used to dry the sludge 01. The ash is collected by a waste heat boiler 52. The quartz sand bin is replenished by external transportation by controlling the slide valve and the cold sand conveyor. S5. Pollutant treatment: The flue gas enters an electrostatic precipitator 61. The particulate matter captured by the static electricity is sent out of the electrostatic precipitator under the action of an ash discharge device 62 and finally goes to comprehensive utilization of ash 63. After the flue gas passes through the electrostatic precipitation, it enters a bag filter 65 through an activated carbon feeder 64. The filtered particulate matter is sent out of the bag filter through a fly ash discharge device 67 and then undergoes fly ash hazardous treatment 67. After the flue gas is filtered by the bag filter, it enters a primary absorption and deacidification tower 661, where desulfurization is carried out by a primary lime solution atomizing sprayer 662. Then it enters a secondary absorption and deacidification tower 664, and after secondary desulfurization by a secondary lime solution atomizing sprayer 665, the flue gas enters a wet electrostatic precipitator 669 to further remove particulate matter, and then is heated to 150 °C by a flue gas heater 671 and a SCR denitration system 672 is added. After denitration, the treated flue gas is sent into a chimney through an induced draft fan for up-to-standard discharge.

[0055] Further, in step S3, the sludge and the crushed leather solid waste are in a ratio of 6:2. In step S4, the temperature in the incinerator is controlled between 850 °C and 900 °C, and the residence time is not less than 2 seconds to ensure the full combustion of the mixed materials.

[0056] As mentioned above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A sludge semi-drying and leather solid waste co-incineration system, characterized in that: It includes a sludge pretreatment unit, a drying unit, a leather processing solid waste pretreatment unit, a co-firing unit and a pollutant treatment unit; The sludge pretreatment unit is used for sludge pretreatment. The sludge pretreatment unit includes sludge (01) and a mechanical grille (02), a sludge slow storage bin (03), a sludge centrifuge (05) and a post-dehydration sludge slow storage bin (06) arranged in sequence; The drying unit is used for sludge drying. The drying unit includes a paddle dryer (010), a dry sludge scraper conveyor I (011), a dry sludge scraper conveyor II (012), a dried sludge buffer bin (013) and a dried sludge buffer bin discharge screw conveyor (014) connected in sequence; The leather processing solid waste pretreatment unit includes a semi-dry leather solid waste pretreatment unit and a dry leather scrap pretreatment unit. The semi-dry leather solid waste pretreatment unit and the dry leather scrap pretreatment unit are respectively connected to a leather scrap mixing unit. The leather scrap mixing unit and the drying unit are respectively connected to a crushed leather and dried sludge mixing unit; The co-firing unit is connected to the crushed leather and dried sludge mixing unit. The pollutant treatment unit is used for purifying the co-firing unit. The pollutant treatment unit includes a particulate matter treatment unit and a desulfurization and denitrification unit that are interconnected; 2. The sludge semi-drying and leather solid waste co-incineration system according to claim 1, characterized in that: The mechanical grille (02) is arranged on the left side of the sludge slow storage bin (03). The sludge slow storage bin (03) is connected to the sludge centrifuge (05) through a sludge transfer pump (04). The discharge end of the sludge centrifuge (05) is provided with a post-dehydration sludge screw conveyor. The side of the post-dehydration sludge screw conveyor away from the sludge centrifuge (05) is located above the post-dehydration sludge slow storage bin (06); The discharge port of the post-dehydration sludge slow storage bin (06) has two paths. One path of the discharge port is connected to the drying unit through a post-dehydration sludge transfer pump (07) and a sludge to dryer plunger pump (09) in sequence. The other path of the discharge port is directly connected to the leather processing solid waste pretreatment unit through a post-dehydration sludge transfer pump (07) and a sludge to incinerator front transfer pump (08) in sequence; 3. A sludge semi-drying and leather solid waste co-incineration system according to claim 2, characterized in that: The sludge to dryer plunger pump (09) is connected to the paddle dryer (010). The top of the paddle dryer (010) is connected with a cyclone dust collector and a carrier gas condensation tower. The carrier gas condensation tower is connected with a demister and a carrier gas fan in sequence. The carrier gas fan transports the gas to the co-firing unit. The top of the dried sludge buffer bin (013) is provided with a bin top dust collector; 4. A sludge semi-drying and leather solid waste co-incineration system according to claim 3, characterized in that: The semi-dry leather solid waste pretreatment unit includes meat residue semi-dry materials (11) and a meat residue pit (12), a semi-dry material grabber (13), a semi-dry material feeder (14), a chain conveyor (15), a semi-dry meat residue feed conveyor (16), a semi-dry meat residue mincer (17), a mincer discharge belt (18) and a pear-shaped distributor (19) arranged in sequence; The dry leather scrap pretreatment unit includes dry leather scraps (21) and a feed chain conveyor (22), a single-shaft crusher (23) and a crusher discharge belt (24) arranged in sequence; The leather scraps mixing unit includes a broken leather buffer pit (31), a broken leather grab crane (32), a broken leather buffer bin (33), and a broken leather buffer bin discharge screw (34) arranged in sequence; The broken leather and dried sludge mixing unit includes a broken leather mixing belt (41), a mixer (42), a mixer discharge screw (43), a bucket elevator (44), a mixed material buffer bin (45), a quantitative weight valve (46), a buffer bin in front of the furnace (47), and an incinerator feed screw (48). The secondary feed port of the incinerator feed screw (48) is connected to the discharge end of the sludge transfer pump to the incinerator (08).

5. A sludge semi-drying and leather solid waste co-combustion system according to claim 4, characterized in that: The co-incineration unit includes a bubbling fluidized bed incinerator (51). The exhaust port of the bubbling fluidized bed incinerator (51) is connected to a waste heat boiler (52). The output end of the incinerator feed screw (48) is connected to the feed end of the bubbling fluidized bed incinerator (51). The gas outlet end of the waste heat boiler (52) is connected to the waste heat steam to dryer (53). The waste heat steam to dryer (53) is connected to the paddle dryer (010). The bottom of the waste heat boiler (52) is sequentially connected to a discharger (54) and a cold ash screw conveyor (55). The cold ash screw conveyor (55) is connected to the ash bin (56).

6. A sludge semi-drying and leather solid waste co-incineration system according to claim 5, characterized in that: There is a quartz sand bin beside the bubbling fluidized bed incinerator (51). The quartz sand bin conveys quartz sand to the bubbling fluidized bed incinerator (51) through a quartz sand conveying screw. The bottom of the bubbling fluidized bed incinerator (51) is sequentially provided with a knife gate valve and a cold sand conveyor.

7. A sludge semi-drying and leather solid waste co-incineration system according to claim 1, characterized in that: The particulate matter treatment unit includes an electrostatic precipitator (61). The left end of the electrostatic precipitator (61) is connected to the waste heat boiler (52). The right end of the electrostatic precipitator (61) is sequentially connected to an activated carbon feeder (64) and a bag filter (65). The bottom of the electrostatic precipitator (61) is connected to an ash discharge device (62) through a screw metering feeder. The bottom of the bag filter (65) is connected to a fly ash discharge device (67) through a screw metering feeder.

8. A sludge semi-drying and leather solid waste co-incineration system according to claim 7, characterized in that: The desulfurization and denitrification unit includes a primary absorption and deacidification tower (661) and a secondary absorption and deacidification tower (664) that are interconnected. A primary lime solution atomizing sprayer (662) and a secondary lime solution atomizing sprayer (665) are respectively arranged inside the primary absorption and deacidification tower (661) and the secondary absorption and deacidification tower (664). The primary lime solution atomizing sprayer (662) and the secondary lime solution atomizing sprayer (665) are respectively connected to limestone slurry (667) through a primary lime solution circulation pump (663) and a secondary lime solution circulation pump (666). The bottom of the secondary absorption and deacidification tower (664) is connected to a waste gypsum dehydrator (668). The top of the secondary absorption and deacidification tower (664) is connected to a wet electrostatic precipitator (669) and a flue gas heater (671). The flue gas heater (671) is connected to an SCR denitrification system (672). A chimney is arranged beside the SCR denitrification system (672).

9. A method for co-incinerating semi-dried sludge and leather solid waste, characterized in that: The sludge semi-drying and leather solid waste co-firing system according to any one of claims 1 to 8 further includes the following steps: S1. Sludge pretreatment: The sludge (01) is lifted by a sludge pump, filtered through a mechanical grille (02), and then enters a sludge slow storage bin (03). At this time, the moisture content of the sludge is about 97%. The sludge (01) is transported to a sludge centrifugal dehydrator (05) by a sludge transfer pump (04). After centrifugal dehydration, the moisture content of the sludge reaches below 80%. It is sent to a post-dehydration sludge slow storage bin (06) through a dehydrated sludge screw conveyor to meet the subsequent drying conditions. S2. Drying: Part of the sludge (01) in the post-dehydration sludge slow storage bin (06) is directly sent to the co-firing unit, and the other part is sent to a paddle dryer (010) by a sludge transfer pump before the incinerator (08) to complete the drying process of the sludge (01). After drying, the sludge (01) is sent to a dried sludge buffer bin (013) through a first dry sludge scraper conveyor (011) and a second dry sludge scraper conveyor (012) in sequence. The dried sludge inside the dried sludge buffer bin (013) is sent to the leather processing solid waste pretreatment unit through a dried sludge buffer bin discharging screw conveyor (014). S3. Leather processing solid waste pretreatment: The collected semi-dry meat residue materials (11) are transported to a meat residue pit (12), fed into a semi-dry material feeder (14) by a semi-dry material grabber (13), and the semi-dry meat residue is sent through a chain conveyor (15) and a semi-dry meat residue feeding conveyor (16) to a semi-dry meat residue meat grinder (17). After being ground into a diameter of 2 mm, it is sent to a leather crushing waste buffer pit (31) through a meat grinder discharge belt (18) and a pear-shaped distributor (19). Dry leather scraps (21) are collected by the workshop and transported to a waste storage room, and then sent to a single-shaft crusher (23) through a feeding chain conveyor (22). After being crushed into a suitable size of less than 3 mm, it is sent to a leather crushing waste buffer pit (31) through a crusher discharge belt (24). The semi-dried leather solid waste and the dry leather scraps are simply mixed by the crushed leather grabber (32) and sent to the crushed leather buffer bin (33), and then sent to the crushed leather mixing belt (41) through the crushed leather buffer bin discharge screw (34) and enter the mixer (42) at the same time as the dried sludge (01), and stirred at a speed of 20 rpm for 15 minutes in the mixer (42). After being fully mixed, they are sent to the lifting bucket and (44) through the mixer discharge screw (43) and enter the mixed material buffer bin (45) for storage, and quantitatively distributed to the furnace front buffer bin (47) through the quantitative hammer valve (46), and then sent to the mixed material and the wet sludge transported by the sludge to the incinerator front delivery pump (08) into the co-incineration unit through the incinerator feed screw (48); S4, blending and incineration: The pre-treated leather processing solid waste is incinerated in a bubbling circulating fluidized bed incinerator (51), and the hot gas after combustion is transported to a paddle dryer (010) via a waste heat steam dryer (53). The heat energy is used to dry the sludge (01), and the ash is collected by a waste heat boiler (52); the material is fed to the quartz sand bin by controlling the gate valve and the cold sand conveyor; S5. Pollutant treatment: The flue gas enters the electrostatic precipitator (61). The particles captured by the electrostatic force are sent out of the electrostatic precipitator under the action of the ash discharger (62), and the ash is finally removed for comprehensive utilization (63). After the flue gas passes through the electrostatic precipitator, it enters the bag filter (65) through the activated carbon feeder (64). The filtered particles are sent out of the bag filter through the fly ash discharger (67) and then subjected to fly ash hazardous disposal (67). After being filtered by the bag filter, the flue gas enters the primary absorption and deacidification tower (661), is desulfurized by the primary lime liquid atomizing sprayer (662), and then enters the secondary absorption and deacidification tower (664). After secondary desulfurization by the secondary lime liquid atomizing sprayer (665), the flue gas enters the wet electrostatic precipitator (669) to further remove particulate matter, is heated to 150°C by the flue gas heater (671), and the SCR denitrification system (672) is added. After denitrification, the treated flue gas is sent to the chimney by the induced draft fan to meet the emission standards.

10. The sludge semi-drying and leather solid waste co-incineration method according to claim 9, characterized in that: In step S3, the sludge and the crushed leather solid waste are mixed in a ratio of 6:2; in step S4, the temperature in the incinerator is controlled between 850℃-900℃, and the residence time is not less than 2 seconds to ensure that the mixed material is fully burned.

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