A municipal sludge dehydration, drying and incineration disposal system without adding fuel

Abstract

A municipal sludge dehydration, drying and incineration disposal system without adding fuel, including a sludge dehydration system, a sludge drying system and a sludge incineration system. The original sludge storage bin is connected to the mixer via a volumetric pump and a conveying pipeline. The mixer is connected to a belt dehydration filter press via a sludge feeder. The belt dehydration filter press is connected to a granulator at the front end of the sludge drying device via a conveying device; the granulator is connected to a belt dryer, and the belt dryer discharge conveying device is connected to a dry mud storage container of the sludge incineration system. The discharge end of the dry mud storage container is provided with a frequency conversion discharge device and a furnace body frequency conversion feeding device and is connected to a gasification-incineration integrated fluidized bed furnace. The present invention initially dehydrates the sludge before drying, controls the moisture content of the mechanically dehydrated semi-dry mud so that the heat required for drying the semi-dry mud matches the heat generated by the incineration of the dry sludge, fundamentally solves the problem of adding auxiliary fuel due to insufficient calorific value of the sludge, reduces operating costs, and saves energy and is environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the field of process flow and machinery, and in particular to a device for treating municipal sludge. Background Art

[0002] Sludge is a solid or semi-solid product produced in the sewage treatment process. It contains a large amount of organic matter, heavy metals, pathogenic bacteria and pathogens. If it is discharged at will, it will cause serious environmental pollution.

[0003] Among the existing sludge treatment technologies, the main process methods used are: sludge landfill, direct incineration, agricultural composting, anaerobic digestion, sludge drying-incineration treatment and other methods.

[0004] Sludge landfill began in the 1960s. Its advantages are simple and convenient treatment methods and low costs. However, direct landfilling of dewatered sludge has an impact on the environment. Pollutants still exist during the landfill process, which is easy to cause secondary pollution. Landfilling occupies a large amount of land area and a large amount of transportation costs;

[0005] Direct incineration has the advantages of high volume and weight reduction rate, fast processing speed, more thorough harmless treatment, and waste heat can be used for power generation or heating. The main purpose of incineration is to incinerate waste as much as possible, make the incinerated materials harmless and reduce the volume to the maximum extent, and minimize the generation of new pollutants to avoid secondary pollution. However, the stability of the combustion process and complete combustion can only be guaranteed when the average calorific value of the sludge and auxiliary fuel entering the furnace is greater than 7000 kJ / kg. For sewage sludge with high water content and low calorific value, auxiliary fuel must be added for incineration treatment.

[0006] Sludge contains rich organic matter and nutrients such as N, P, K, and various trace elements necessary for plant growth. Through composting, the organic matter in the sludge is biochemically degraded and converted into stable humus. Applying it to farmland can improve soil structure, increase soil fertility, and promote crop growth; but there is a risk of pathogenic bacteria spread and POPs and heavy metal pollution. For this reason, governments of various countries have successively promulgated agricultural sludge heavy metal standards and strict harmless requirements, and have strict restrictions on the application of sludge per unit area of ​​land. If dehydrated sludge is used for agricultural composting for a long time, it may affect human health due to the accumulation of harmful substances such as heavy metals and furans.

[0007] Anaerobic digestion of sludge is a process in which anaerobic microorganisms decompose and stabilize the organic matter in the sludge. The decomposition process can be divided into two stages: acid production and gas production. Energy is released during the reaction and methane gas is produced.

[0008] However, the anaerobic sludge digestion process is relatively complicated to operate, the equipment failure rate is high and the amount of biogas produced is small. The key equipment for anaerobic sludge digestion requires high precision, and the automatic control and maintenance are complex and expensive, making it difficult to operate.

[0009] The sludge drying and incineration process refers to the process of first using a heat source to heat the dehydrated sludge to further remove the moisture in the sludge, and then putting the sludge with reduced moisture content into an incinerator to directly burn the organic matter into CO2, NO and inorganic matter, thereby achieving its reduction and effective energy utilization.

[0010] However, the existing sludge drying and incineration technology has the problems that the calorific value of the dried sludge is unbalanced with the drying heat, and auxiliary fuel still needs to be added to make up for the drying heat of the dry sludge; the comprehensive utilization rate of the three wastes generated by sludge treatment is not high. Summary of the invention

[0011] The technical problem solved by the present invention is that auxiliary fuel needs to be added in the current sludge treatment process. The present invention provides an integrated sludge dehydration, drying and incineration treatment system, which does not require the addition of fuel, and a sludge treatment device for comprehensive utilization of waste gas, waste water and waste residue. The problem of lack of heat in the sludge treatment process, the need to add auxiliary combustion fuel, and the low utilization of the three wastes is solved, thus achieving the purpose of energy saving and environmental protection.

[0012] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: a municipal sludge dehydration, drying and incineration disposal system without adding fuel, including a sludge dehydration system, a sludge drying system and a sludge incineration system. In the sludge dehydration system, the original sludge storage bin is connected to the mixer via a volumetric pump and a conveying pipeline, the mixer is connected to the belt dehydration filter press via a sludge feeder, and the belt dehydration filter press is connected to the sludge drying system via a conveying device;

[0013] The sludge drying system, the conveying device is connected to the belt dryer through the granulator, and a flue gas induced draft fan with adjustable air supply volume and an air distribution device for controlling the air supply volume are provided. According to the amount of dry material, the air volume of the flue gas induced draft fan is adjusted to control the temperature required by each layer of mesh belt in the belt dryer. The air supply volume is controlled by the air distribution device to control the flue gas temperature at the inlet of the belt dryer; the belt dryer discharge conveyor is connected to the sludge incineration system;

[0014] The sludge incineration system, the belt dryer discharge is connected to the storage container through a conveying device, the discharge end of the storage container is provided with a frequency conversion discharge device and a furnace body frequency conversion feeding device, the storage container is connected to the gasification-incineration integrated fluidized bed furnace through the discharge device and the feeding device; the gasification-incineration integrated fluidized bed furnace body is a longitudinal furnace body, the inside of the furnace body is respectively provided with a dense phase zone, a dilute phase zone and a transition zone from bottom to top, the lower part of the furnace body is provided with a wind chamber and a water-cooled air distribution plate, the top of the furnace body is connected to a high-temperature gas-solid separation device, below the dense phase zone is an air distribution plate for generating fluidized air in the furnace body, below the air distribution plate is an air chamber, the outside of the air chamber is connected to a primary air duct and a primary air fan, the upper part of the dense phase zone is connected to a secondary air duct and a secondary air fan.

[0015] Furthermore, the system is also provided with a waste gas, waste water, and waste residue comprehensive utilization system. In the waste gas comprehensive utilization part, the flue gas outlet of the belt dryer is connected to the gas-solid separator, and the separator is connected to the flue gas waste heat utilization heating facility, the washing tower, and the flue gas outlet in sequence; the solid particulate matter discharged from the separator is connected to the storage container;

[0016] In the wastewater comprehensive utilization part, the outlet of the sludge dehydration system is connected to the first-level physical precipitation equipment, the clear liquid outlet of the physical precipitation equipment is connected to the flushing water pipe of the belt dehydration filter press, and the bottom liquid outlet after precipitation of the physical precipitation equipment is connected to the flushing water pipe of the belt dehydration filter press and the flue gas washing water pipe after passing through the two-stage anaerobic treatment equipment; In the waste residue comprehensive utilization part, the solid ash residue outlet separated by the high-temperature gas-solid separation device in the sludge incineration system is connected to the collection container and transported to the construction production workshop.

[0017] Furthermore, in the sludge dewatering system, the mixer is cylindrical in shape, divided into two layers, upper and lower, and equipped with rotating blades. The upper layer is for coarse mixing, and the lower layer is for even mixing. The speed of the blades is controlled to achieve control of the mixing uniformity and mixing time. The sludge feeder is located at the feed port of the belt dewatering filter press below the mixer, and the width and thickness of the original sludge fed to the dewatering filter press are adjusted according to the original sludge input amount and water content.

[0018] Furthermore, the belt dewatering filter press has a filter belt deviation corrector for automatically correcting the filter belt during operation of the dewatering filter press; a filter belt hydraulic tensioning device for adjusting the pressure value of the filter belt; a timed flushing nozzle for cleaning residual sludge on the filter belt; and a semi-dry sludge scraper for peeling the semi-dry sludge obtained after dehydration from the filter belt and feeding it into a conveying device.

[0019] Furthermore, in the sludge drying system, the upper opening of the granulator casing is the receiving opening, and the lower opening is the discharging opening. A material distributor, a material breaking assembly, a reciprocating material distributor, and a roller shearing granulation assembly are sequentially arranged in the granulator casing from top to bottom; the roller shearing granulation assembly comprises two parallel toothed shearing rollers that penetrate the casing, the two shearing rollers are respectively an active shearing roller and a driven shearing roller, the active shearing roller and the driven shearing roller are meshed with gears that protrude out of the granulator casing, the active shearing roller is connected to the shearing power device, and the active shearing roller and the driven shearing roller are meshed with gears. There are concave and convex shearing teeth on the upper part of the movable shearing roller box, and the shearing teeth on the two shearing rollers mesh with each other; the distributor of the granulator is located in the middle of the receiving port of the box, which is a material guide trough welded by several steel plates; the material breaking component of the granulator is located below the distributor, and consists of a stationary metal grating plate and a reciprocating scraper bar. The scraper bar is movably placed on the metal grating plate, and the length direction of the scraper bar is perpendicular to the reciprocating motion direction. The scraper bar and the feeder share a crank connecting rod and a scraper power device connected to the reciprocating motion.

[0020] Furthermore, in the sludge drying system, the belt dryer is a through-flow sludge belt dryer integrating granulation, drying, cleaning and other devices, including a body, which is a box-type body, which is made of metal plates, and the box-type body is covered with an insulation layer. The body is provided with a feed port and a discharge port, and there are several drying layers from top to bottom in the body, and the drying layers are metal mesh conveyor belts, and the conveyor belts of adjacent drying layers run in opposite directions; a total air inlet is provided on the top of the body, and the total air inlet is connected to a number of air supply branches, and the air supply branches are connected to layered rectangular air inlets, and the layered rectangular air inlets are arranged along the direction of the conveyor belt, and there are a number of through-flow air supply pipes that are oblique or perpendicular to the direction of the conveyor belt in the layered rectangular air inlet, and an adjustable valve is provided at the entrance of each layered rectangular air inlet; an exhaust port is provided at the bottom of the body, and the lowest layer of the body is a cleaning layer, and a feed port is provided at the upper part of the body, and a granulator is installed above the feed port.

[0021] Furthermore, the conveyor belt drive is connected to a stepless speed regulator, and a plurality of temperature sensors and pressure sensors are respectively provided below each drying layer.

[0022] Furthermore, the cleaning layer includes a cleaning walking mechanism, cleaning strips and a power device for driving the walking mechanism. The cleaning walking mechanism is composed of a driving shaft and a driven shaft, which are respectively installed on a support seat. The driving shaft and the driven shaft have toothed discs at both ends, and a closed chain is installed on the toothed disc. A number of cleaning strips are arranged at intervals on the chain, and the driving shaft is connected to the power device.

[0023] Compared with the prior art, the present invention has a positive and obvious effect. Before the sludge is dried, the present invention performs mechanical primary dehydration to solve the problem of imbalance between the calorific value of the sludge and the drying heat. By controlling the moisture content of the mechanically dehydrated semi-dry sludge to match the heat generated by the incineration of the dry sludge, the problem of adding auxiliary fuel due to insufficient calorific value of the sludge in the prior art is fundamentally solved, the operating cost is reduced, and the advanced concept of energy conservation and environmental protection is fully embodied. At the same time, compared with the prior art, the present invention has a significant breakthrough in the comprehensive utilization of the three wastes. The waste heat in the discharged exhaust gas is used as a heating source in winter, which not only saves heating energy consumption, but also reduces the discharged water vapor. The waste water removed from the sludge is used as production water after treatment, which not only reduces the discharge of sewage but also solves the source of production water. The solid waste residue generated during drying and incineration is fully utilized, and additional economic benefits are obtained therefrom. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0025] Figure 2 It is a structural schematic diagram of the belt dryer of the present invention.

[0026] Figure 3 yes Figure 2 Schematic diagram of the external air duct of the belt dryer cabinet.

[0027] Figure 4 It is a schematic diagram of the structure of the granulator of the present invention.

[0028] Figure 5 yes Figure 4 Schematic diagram of the crushing component structure in a granulator. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific embodiments, but the present invention is not limited to the specific embodiments.

[0030] Example 1

[0031] like Figure 1 A municipal sludge dehydration, drying and incineration disposal system without adding fuel is shown, comprising a sludge dehydration system, a sludge drying system and a sludge incineration system. In the sludge dehydration system, the original sludge storage bin 4 is connected to the mixer 301 via a volumetric pump 5 and a conveying pipeline, the mixer is connected to the belt dehydration filter press 3 via a sludge feeder 302, and the belt dehydration filter press is connected to the sludge drying system via a conveying device 19;

[0032] The sludge drying system, the conveying device 19 is connected to the belt dryer 2 through the granulator 7, and a flue gas induced draft fan 8 with adjustable air supply volume and an air distribution device 9 for controlling the air supply volume are provided. According to the amount of dry material, the air volume of the flue gas induced draft fan is adjusted to control the temperature required by each layer of mesh belt in the belt dryer. The air supply volume is controlled by the air distribution device to control the flue gas temperature at the inlet of the belt dryer; the belt dryer discharge conveyor is connected to the sludge incineration system;

[0033] In the sludge incineration system, the discharge of the belt dryer 2 is connected to the storage container 10 through a conveying device, and the discharge end of the storage container is provided with a variable frequency discharge device 13 and a furnace body variable frequency feeding device 14, and the storage container is connected to the gasification-incineration integrated fluidized bed furnace 1 through the discharge device and the feeding device; the gasification-incineration integrated fluidized bed furnace body is a longitudinal furnace body, and a dense phase zone 101, a dilute phase zone 102, and a transition zone 103 are respectively arranged from bottom to top inside the furnace body, and a wind chamber and a water-cooled air distribution plate are arranged at the lower part of the furnace body, and the top of the furnace body is connected to a high-temperature gas-solid separation device 15, and below the dense phase zone is an air distribution plate for generating fluidized air in the furnace body, and below the air distribution plate is a wind chamber, and the outside of the wind chamber is connected to a primary air duct and a primary air fan 11, and the upper part of the dense phase zone is connected to a secondary air duct and a secondary air fan 12.

[0034] Embodiment 2:

[0035] like Figure 1 As shown, on the basis of Example 1, in the sludge dewatering system, the sludge mixer 301 is cylindrical in shape, and the mixer body 303 is divided into an upper layer and a lower layer and is provided with rotating blades to achieve the purpose of coarse mixing of the upper layer and uniform mixing of the lower layer, and the speed control of the blades is used to control the mixing uniformity and mixing time.

[0036] The sludge feeder 302 is located at the feeding port of the belt dewatering filter press below the mixer 301. According to the input amount and moisture content of the original sludge, the width and thickness of the original sludge fed to the dewatering filter press can be adjusted.

[0037] The belt dewatering filter press 3 is provided with a filter belt deviation corrector for automatically correcting the filter belt during operation of the dewatering filter press; a filter belt hydraulic tensioning device for adjusting the pressure value of the filter belt, and a timed flushing nozzle for cleaning the residual sludge on the filter belt; and a semi-dry sludge scraper for stripping the semi-dry sludge obtained after dehydration from the filter belt and feeding it into a conveying device.

[0038] Example 3

[0039] like Figure 1 As shown, based on Example 1 or 2, in the sludge drying system, the belt dryer 2 is a through-flow sludge belt dryer integrating granulation, drying, cleaning and other devices. The specific structure is as follows Figure 2As shown, it includes a machine body, which is a box-type machine body 201. The machine body is a box-type machine body made of metal plates, and the box-type machine body is coated with an insulation layer. The machine body is provided with a feed port 210 and a discharge port 208. There are several drying layers 202 in the machine body from top to bottom. The drying layers are metal mesh conveyor belts, and the conveyor belts of adjacent drying layers run in opposite directions. A total air inlet 203 is provided on the top of the machine body. The total air inlet 203 is connected to a number of air supply branches 216. The air supply branches are connected to layered rectangular air inlets 204. The layered rectangular air inlets are arranged along the direction of the conveyor belt. There are a number of through-flow air supply pipes 205 that are oblique or perpendicular to the direction of the conveyor belt in the layered rectangular air inlet. An adjustable valve is provided at the entrance of each layered rectangular air inlet; an exhaust port 206 is provided at the bottom of the machine body, and the lowest layer of the machine body is a cleaning layer 207. A feed port is provided on the upper part of the machine body, and a granulator 7 is installed on the upper part of the feed port.

[0040] The conveyor belt drive is connected to a stepless speed regulator, and a plurality of temperature sensors 212 and pressure sensors 213 are respectively provided below each drying layer.

[0041] The cleaning layer is as Figure 3 As shown, it includes a cleaning travel mechanism, a cleaning strip 209 and a power device 211 for driving the travel mechanism. The cleaning travel mechanism is composed of a driving shaft 214 and a driven shaft 215. The driving shaft and the driven shaft are respectively installed on the support seat. Both ends of the driving shaft and the driven shaft are provided with a toothed plate, and a closed chain is installed on the toothed plate. A number of cleaning strips are arranged at intervals on the chain. The driving shaft is connected to the power device.

[0042] The main air outlet is provided with a temperature sensor and a humidity sensor for judging the degree of heat utilization in the drying air and whether the heat matches the material.

[0043] Granulator 7 Figure 4 , 5As shown, the upper opening of the box is the receiving opening, and the lower opening is the discharging opening. A distributor 702, a material breaking assembly 703, a reciprocating material distributor 704, and a roller shearing and pressing granulating assembly 705 are arranged in the granulator box 701 from top to bottom in sequence; the roller shearing and pressing granulating assembly 705 includes two parallel toothed shearing and pressing rollers that penetrate the box, the two shearing and pressing rollers are respectively an active shearing and pressing roller and a driven shearing and pressing roller, the active shearing and pressing rollers and the driven shearing and pressing rollers protrude out of the granulator box and are meshed with gears, the active shearing and pressing rollers are connected to the shearing and pressing power device 710, and the active shearing and pressing rollers and the driven shearing and pressing rollers are in the box. There are shearing teeth with concave and convex shapes on the inner roller body, and the shearing teeth on the two shearing rollers mesh with each other; the distributor 702 of the granulator is located in the middle of the material receiving port of the box body, which is a guide trough welded by several steel plates; the material breaking assembly 703 of the granulator is located below the distributor, and is composed of a stationary metal grid screen plate 706 and a scraper bar 707 that moves back and forth. The scraper bar is movably placed on the metal grid screen plate, and the length direction of the scraper bar is perpendicular to the reciprocating motion direction. The scraper bar and the feeder share a crank connecting rod 708 and a scraper power device 709 that connect the reciprocating motion. The drying layers in the machine body are parallel to each other. The unloading part of the granulator is a shearing device, which can effectively cut off hair, plastic and other debris in the semi-dried sludge, and the unloading is smooth and unblocked.

[0044] The main body of the belt dryer 2 is a multi-layer reciprocating type. The drying air volume supplied to each layer is controlled according to the temperature. The bottom layer of the belt dryer is equipped with a dust cleaning device to send the material falling from the mesh belt and the dry sludge to the discharge end together. There is no material accumulation in the dryer; the drying air adopts a layered flow method to penetrate the material layer to be dried with hot air. The running speed of each layer of the mesh belt of the dryer is adjustable. The thickness of the dried material and the residence time of the dried material in the dryer can be controlled by adjusting the running speed of the mesh belt.

[0045] A variable frequency flue gas induced draft fan 8 capable of adjusting the amount of hot drying air and an air distribution device 9 for controlling the amount of air distribution are provided. According to the amount of drying material, the air volume of the flue gas induced draft fan is adjusted to control the required temperature of each layer of mesh belt in the dryer, and the air distribution device is used to control the amount of air distribution to control the flue gas temperature at the dryer inlet.

[0046] The present invention granulates the dehydrated semi-dry sludge through a specific granulator 7 and then sends it to the belt dryer 2 for drying. The heat source for drying comes from the incineration of the dried dry sludge. The hot flue gas generated by the incineration of the dry sludge is sent to the dryer by a flue gas induced draft fan after air distribution. The heat required for drying the semi-dry sludge and the heat generated by the incineration of the dry sludge are matched by controlling the moisture content of the semi-dry sludge, and no other fuel needs to be added.

[0047] Example 4

[0048] Based on any of the above embodiments, in the sludge incineration system, the incinerator is a bubbling internal circulating fluidized bed incinerator capable of self-sustaining incineration of low calorific value sludge, involving an incinerator body, the top of which is open, and the interior is a furnace hall, which is arranged vertically and is divided into a dense phase area, a dilute phase area and a transition area from bottom to top, and a water-cooled air distribution plate is provided at the bottom of the furnace hall, and a wind chamber is provided at the lower part of the water-cooled air distribution plate, the wind chamber is connected to the igniter, and the slag discharge pipe is connected from the water-cooled air distribution plate through the wind chamber to the vibrating slag discharger outside the furnace hall; the wind chamber has a primary air duct connected to the primary air fan, and the furnace hall dense phase area has a secondary air duct connected to the secondary air fan. The top opening of the incinerator body is connected to the cyclone dust collector, and the outlet flue of the cyclone dust collector is provided with an air distribution chamber and a gas-solid separator for secondary purification of smoke. A dry sludge storage bin and a dry sludge on-demand quantitative feeder with broadcasting wind are installed at the bottom of the dense phase area of ​​the incinerator body.

[0049] The upper and lower sides of the water-cooled air distribution plate are covered with a refractory material layer. The water-cooled air distribution plate is composed of evenly arranged wind caps and multiple parallel water-cooling pipes. The wind cap openings are arranged in two or more layers, and the wind cap openings have a downward angle. The slag discharge pipe is provided with a slag discharge port in the middle of the water-cooled air distribution plate. The slag discharge pipe passes through the wind chamber and is connected to the vibrating slag discharge device. The slag discharge pipe is provided with a water-cooling sleeve.

[0050] The secondary air duct is divided into a main air duct and a branch air duct. The main air duct is connected to the secondary air fan. The incinerator body is connected to a plurality of branch air ducts. The branch air ducts are connected to the main air duct. The branch air ducts are arranged to ensure that the secondary air is sprayed into the furnace in a tangential manner. The air distribution chamber is a device that can automatically adjust the air volume of the air distribution chamber.

[0051] The dry sludge storage bin is a cylindrical container with a cone-shaped bottom. A feeder with adjustable dry sludge amount is provided at the discharge port of the cone. An access pipe for broadcasting air is provided at the front end of the feeder. The feeder is a variable frequency spiral feeder with broadcasting air.

[0052] The dried mud is sent to the storage container. Depending on the heat demand in the dryer, the dry mud in the container is quantitatively sent to the gasification-incineration integrated fluidized bed furnace for incineration. The sludge gasification temperature in the gasification zone of the furnace is controlled by adjusting the size of the primary air volume; the gas combustion temperature is controlled by controlling the size of the secondary air volume. Through the control of the above three aspects, the heat output of the gasification-incineration integrated fluidized bed furnace can be controlled.

[0053] The dry mud is first gasified in the furnace. This process is located in the dense phase area. By controlling the injection amount of the primary air, the gasification process is carried out under conditions lower than the theoretical oxygen amount. The sludge is heated to a certain temperature, and the temperature is used to drive the thermal cracking and thermochemical conversion reactions of the organic matter in the sludge, so that the sludge is converted into combustibles such as pyrolysis gas and coke.

[0054] The dilute phase zone is the gasification gas combustion zone. In this zone, the gasification gas is fully burned under reasonable excess air conditions by controlling the injection amount of secondary air. The gasification gas combustion temperature is high, so that the dioxins produced in the reaction process are completely decomposed; the transition zone is an area before the gasification gas enters the flue on the top of the furnace after high-temperature incineration. In this area, the unburned gasification gas is further burned, and the unburned fuel particles in the furnace fall back to the dense phase zone, forming an internal circulation of fuel in the furnace. The high-temperature flue gas generated by the incineration of dry sludge will be purified. This process is located after the transition zone. A set of high-temperature gas-solid separation device is installed in the furnace body. Subsequently, the flue gas temperature is reduced to 300~350℃ by air distribution, and then high-efficiency gas-solid separation is performed and used as a drying heat source for the dryer.

[0055] Example 5

[0056] like Figure 1 As shown, in the step of comprehensive utilization of waste gas and purification to meet emission standards, the low-temperature flue gas discharged from the dryer is separated into gas and solid, and the waste heat in the flue gas is used for heating in the production area, and the flue gas meets emission standards after chemical and physical washing.

[0057] In the step of comprehensive utilization of waste gas and purification to meet emission standards, the flue gas after gas-solid separation is introduced into the production area through a heat dissipation device, and the waste heat in the flue gas is radiated to the production area for heating in winter, saving heating energy consumption;

[0058] In the steps of comprehensive utilization of waste gas and purification to meet emission standards, before the waste gas is discharged, it undergoes multi-stage acid washing, alkali washing and water washing to remove ammonia, acidic gases and other harmful substances in the flue gas, and the flue gas becomes neutral and meets emission standards.

[0059] Furthermore, in the step of comprehensive utilization of wastewater without external discharge of wastewater, the sludge removed in the sludge dewatering step contains water, and the clear liquid after primary physical precipitation and conditioning is used as flushing water for the belt dewatering filter press. The bottom liquid after precipitation is treated by two-stage anaerobic and other biochemical methods, and after meeting the standards, it is used as flushing water for the belt dewatering filter press and flue gas washing water in the step of flue gas purification and emission meeting the standards.

[0060] Furthermore, in the step of comprehensive utilization of waste residues without external discharge of waste residues, the solid ash separated by the high-temperature gas-solid separation device of the gasification-incineration integrated fluidized bed furnace in the sludge incineration step is comprehensively utilized and made into unfired bricks or unfired building panels with ash as the main component; in the step of comprehensive utilization of waste flue gas and purification to meet emission standards, the solid particles separated by gas-solid separation of the waste flue gas are returned to the dry mud storage container located in the incinerator area as fuel.

Claims

1. A municipal sludge dehydration, drying and incineration disposal system without adding fuel, comprising a sludge dehydration system, a sludge drying system and a sludge incineration system, characterized in that: In the sludge dewatering system, the original sludge storage bin (4) is connected to the mixer (301) via a volumetric pump (5) and a conveying pipeline, the mixer is connected to the belt dewatering filter press (3) via a sludge feeder (302), and the belt dewatering filter press is connected to the sludge drying system via a conveying device (19); the mixer (301) is cylindrical in shape, divided into an upper layer and a lower layer and provided with rotating blades, the upper layer is for rough mixing, the lower layer is for even mixing, and the speed of the blades is controlled to achieve control of the mixing uniformity and mixing time; the sludge feeder (302) is located at the feed port of the belt dewatering filter press below the mixer, and adjusts the width and thickness of the original sludge fed to the dewatering filter press according to the original sludge input amount and moisture content; The sludge drying system comprises a conveying device (19) connected to a belt dryer (2) via a granulator (7), and is provided with a flue gas induced draft fan (8) capable of adjusting the supply air volume and an air distribution device (9) for controlling the air distribution volume. The air volume of the flue gas induced draft fan is adjusted according to the amount of drying material to control the required temperature of each layer of mesh belt in the belt dryer, and the air distribution device controls the air distribution volume to control the flue gas temperature at the inlet of the belt dryer; The belt dryer discharge conveyor is connected to the sludge incineration system. The belt dryer (2) is a through-flow sludge belt dryer integrating granulation, drying and cleaning devices, comprising a machine body, which is a box-type machine body (201). The machine body is a box-type machine body made of metal plates. The box-type machine body is covered with an insulation layer. The machine body is provided with a feed inlet (210) and a discharge inlet (208). There are several drying layers (202) from top to bottom in the machine body. The drying layers are metal mesh conveyor belts. The conveyor belts of adjacent drying layers run in opposite directions. A main air inlet duct (203) is provided on the top of the machine body. The main air inlet duct is connected to several air supply branch pipes (216). The air supply branch pipes are connected to layered rectangular air inlets (204). The layered rectangular air inlets are arranged along the conveyor belt direction. There are a plurality of through-flow air supply pipes (205) in the conveyor belt, which are obliquely or perpendicularly arranged to the conveyor belt direction, and an adjustable valve is arranged at the entrance of each layered rectangular air inlet duct; an exhaust port (206) is arranged below the machine body, and the lowest layer of the machine body is a cleaning layer (207), the cleaning layer comprises a cleaning travel mechanism, cleaning strips (209) and a power device (211) for driving the travel mechanism to operate, the cleaning travel mechanism is composed of a driving shaft (214) and a driven shaft (215), the driving shaft and the driven shaft are respectively mounted on a support seat, and the driving shaft and the driven shaft have toothed discs at both ends, the toothed discs are mounted with closed chains, a plurality of cleaning strips are arranged at intervals on the chains, and the driving shaft is connected to the power device; a feed inlet is arranged at the top of the machine body, and a granulator (7) is mounted above the feed inlet; The upper opening of the granulator (7) housing is a material receiving opening, and the lower opening is a material discharging opening. The granulator housing (701) is provided with a material distributor (702), a material breaking assembly (703), a reciprocating material distributor (704), and a roller shearing and pressing granulating assembly (705) in order from top to bottom. The roller shearing and pressing granulating assembly (705) comprises two parallel toothed shearing and pressing rollers penetrating the housing, the two shearing and pressing rollers are respectively an active shearing and pressing roller and a driven shearing and pressing roller, the active shearing and pressing roller and the driven shearing and pressing roller protruding out of the granulator housing are meshed with gears, the active shearing and pressing roller is connected to a shearing and pressing power device (710), and the active shearing and pressing roller and the driven shearing and pressing roller are respectively connected to a shearing and pressing power device (710). The roller body of the roller box has concave and convex shearing teeth arranged alternately, and the shearing teeth on the two shearing rollers mesh with each other; the distributor (702) of the granulator is located in the middle of the material receiving port of the box, and is a material guide trough formed by welding a plurality of steel plates; the material breaking assembly (703) of the granulator is located below the distributor, and is composed of a stationary metal grating plate (706) and a scraper bar (707) that performs reciprocating motion, the scraper bar is movably placed on the metal grating plate, the length direction of the scraper bar is perpendicular to the reciprocating motion direction, and the scraper bar and the material distributor share a crank connecting rod (708) that is connected to the reciprocating motion and a scraper power device (709); The sludge incineration system comprises a belt dryer (2) whose discharge is connected to a storage container (10) via a conveying device, a variable frequency discharge device (13) and a furnace body variable frequency feeding device (14) being provided at the discharge end of the storage container, and the storage container being connected to a gasification-incineration integrated fluidized bed furnace (1) via the discharge device and the feeding device; the gasification-incineration integrated fluidized bed furnace body is a longitudinal furnace body, and a dense phase zone (101), a dilute phase zone (102), and a transition zone (103) are respectively arranged inside the furnace body from bottom to top, and a wind chamber and a water-cooled air distribution plate are arranged at the bottom of the furnace body, and the top of the furnace body is connected to a high-temperature gas-solid separation device (15), and an air distribution plate for generating fluidized air for the furnace body is provided below the dense phase zone, and an air chamber is provided below the air distribution plate, and the air chamber is connected to a primary air duct and a primary air fan (11) outside the air chamber, and a secondary air duct and a secondary air fan are connected to the upper part of the dense phase zone. The secondary air fan (12) is a dense phase zone, in which the gasification process is carried out under the condition of lower than the theoretical oxygen amount by controlling the injection amount of the primary air, the sludge is heated to a certain temperature, and the temperature is used to drive the thermal cracking and thermochemical conversion reaction of the organic matter in the sludge, so that the sludge is converted into combustibles such as pyrolysis gas and coke. The dilute phase zone is a gasification gas combustion zone. In this zone, the gasification gas is fully burned under reasonable excess air conditions by controlling the injection amount of the secondary air. The gasification gas has a high combustion temperature, so that the dioxins generated during the reaction are completely decomposed. The transition zone is a zone before the gasification gas enters the furnace top flue after high-temperature incineration. In this zone, the unburned gasification gas is further burned, and the unburned fuel particles in the furnace fall back to the dense phase zone, forming an internal circulation of the fuel in the furnace.

2. A municipal sludge dehydration, drying and incineration disposal system without adding fuel according to claim 1, characterized in that: The system is also provided with a waste gas, waste water and waste residue comprehensive utilization system. In the waste gas comprehensive utilization part, the flue gas outlet of the belt dryer is connected to a gas-solid separator (16), and the separator is connected in sequence to a flue gas waste heat utilization heating facility, a washing tower and a flue gas outlet; the solid particulate matter discharged from the separator is connected to a storage container (10); In the wastewater comprehensive utilization part, the effluent of the sludge dehydration system is connected to the primary physical precipitation device (18), the clear liquid outlet of the physical precipitation device is connected to the flushing water pipe of the belt dehydration filter press (3), and the bottom liquid outlet after precipitation of the physical precipitation device is connected to the flushing water pipe of the belt dehydration filter press and the flue gas washing water pipe after passing through the two-stage anaerobic treatment device (20); In the waste residue comprehensive utilization part, the solid ash outlet separated by the high-temperature gas-solid separation device in the sludge incineration system is connected to the collection container and transported to the construction production workshop.

3. A municipal sludge dehydration, drying and incineration disposal system without adding fuel according to claim 1 or 2, characterized in that: The belt dewatering filter press (3) has a filter belt deviation corrector for automatically correcting the deviation of the filter belt during operation of the dewatering filter press; a filter belt hydraulic tensioning device for adjusting the pressure value of the filter belt; a timed flushing nozzle for cleaning the residual sludge on the filter belt; and a semi-dry sludge scraper for stripping the semi-dry sludge obtained after dehydration from the filter belt and feeding it into a conveying device.

4. A municipal sludge dehydration, drying and incineration disposal system without adding fuel according to claim 1 or 2, characterized in that: The conveyor belt drive is connected to a stepless speed regulator, and a plurality of temperature sensors (212) and pressure sensors (213) are respectively provided below each drying layer.

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