CN110217969B

CN110217969B - Comprehensive treatment process for sludge of urban sewage plant

Info

Publication number: CN110217969B
Application number: CN201910555764.XA
Authority: CN
Inventors: 黄波; 程伟
Original assignee: Zhejiang Qihang Environment Group Co ltd
Current assignee: Zhejiang Qihang Environment Group Co ltd
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2022-01-18
Anticipated expiration: 2039-06-25
Also published as: CN110217969A

Abstract

The invention relates to the technical field of sludge treatment, in particular to a comprehensive treatment process for sludge in an urban sewage plant. Which comprises the following steps: (1) feeding the sludge into a filter pressing device for dehydration to obtain dehydrated water and dehydrated sludge; (2) the dehydrated sludge is sent into an incineration device for incineration, the smoke generated by incineration is sent into a smoke purification device for evacuation, and the waste residue generated by incineration is sent into a building material sintering device; the flue gas purification device sequentially comprises a liquid nitrogen denitration unit, a quenching deacidification unit, a cloth bag dust removal unit, a wet washing unit and a temperature raising unit; (3) sending the dehydrated water into a steam generating device, sending the generated steam into a temperature raising unit, converting the steam into condensed water after heat exchange, and sending the condensed water into a wet washing unit; and residual scale remained in the steam generating device is sent to the building material sintering device. The invention has the characteristics of good sludge treatment effect, energy conservation, environmental protection and low cost.

Description

Comprehensive treatment process for sludge of urban sewage plant

Technical Field

The invention relates to the technical field of sludge treatment, in particular to a comprehensive treatment process for sludge in an urban sewage plant.

Background

All cities in the city must be constructed with sewage treatment facilities. In view of many people, the water supply environmental protection problem of a city is solved as long as a sewage treatment plant is arranged in the city. And the fact is that the municipal sewage treatment plant necessarily produces sludge during the sewage treatment process. And with the continuous improvement of the urban sewage treatment rate, the sludge yield is also continuously increased. At present, the total amount of sludge produced in the whole country every year reaches 900 ten thousand tons, and a large amount of sludge with extremely high water content produced by urban pipeline dredging and river channel dredging is not included. At present, the standardized treatment rate of sludge in national sewage treatment plants is less than 20%, and the problem of sludge treatment becomes a bottleneck problem which restricts the healthy development of the whole sewage treatment industry.

At present, methods for treating sludge in various countries in the world mainly comprise landfill, sea throwing, composting, incineration and the like, wherein the landfill is simple and easy to carry out, but a large amount of land is occupied, a large amount of transportation cost is spent, and the periphery of a landfill site is damaged by leachate and odor. Throwing into the sea can have a very bad influence on the marine environment. Composting is a method for making treated sludge agricultural by utilizing nutrient elements such as nitrogen, phosphorus and the like contained in the sludge. Composting can reduce the volume and stabilize the sludge, but due to the problems of heavy metal deposition and organic pollution in the sludge, the method must be used carefully. The incineration is to utilize a large amount of organic matters in the sludge to burn the sludge into ash at high temperature so as to achieve the purposes of volume reduction, stabilization and harmlessness. The incineration method has many advantages over the above methods: the sludge can be incinerated in situ, the sludge treatment speed is high, the volume of the sludge can be reduced to the maximum extent, the problem of heavy metal ions is avoided, the energy can be recovered for power generation and heat supply, and the incineration ash can be used for paving, making bricks, preparing ceramsite and the like. How to incinerate is a key direction for research, which can ensure that the environment is not affected by incinerated waste gas, reduce the cost of sludge incineration and improve the economic benefit.

Disclosure of Invention

The invention aims to solve the problems and provides a comprehensive treatment process for sludge in an urban sewage plant, which has the advantages of good treatment effect, energy conservation, environmental protection and low cost.

The technical scheme for solving the problems is to provide a comprehensive treatment process for sludge in an urban sewage plant, which comprises the following steps:

(1) feeding the sludge into a filter pressing device for dehydration to obtain dehydrated water and dehydrated sludge;

(2) the dehydrated sludge is sent into an incineration device for incineration, the smoke generated by incineration is sent into a smoke purification device for evacuation, and the waste residue generated by incineration is sent into a building material sintering device; the flue gas purification device sequentially comprises a liquid nitrogen denitration unit, a quenching deacidification unit, a cloth bag dust removal unit, a wet washing unit and a temperature raising unit;

(3) sending the dehydrated water into a steam generating device, sending the generated steam into a temperature raising unit, converting the steam into condensed water after heat exchange, and sending the condensed water into a wet washing unit; and residual scale remained in the steam generating device is sent to the building material sintering device.

Preferably, the incineration device comprises a furnace body and a blanking pipe arranged on the side wall of the furnace body and communicated with the incineration cavity in the furnace body, and the included angle between the blanking pipe and the furnace wall of the furnace body is 40-50 degrees; a plurality of air caps communicated with the first air blower are installed in the blanking pipe, and the air caps are vertically installed on the pipe wall of the blanking pipe.

Preferably, a heat preservation shell is sleeved outside the furnace body, an air pipe communicated with the second blower is arranged between the furnace body and the heat preservation shell, and heat conduction oil is communicated between the outer wall of the air pipe, the heat preservation layer and the furnace body; the air outlet of tuber pipe sets up in the bottom that the furnace body burns the chamber, just the air outlet intercommunication has the blast pipe of laying in the furnace body bottom, being close to the one side that burns the chamber and being equipped with a plurality of gas pockets.

Preferably, the air inlet of the air pipe is provided with a dehumidifier, the center of one surface of the exhaust pipe, which is far away from the incineration cavity, protrudes out of the incineration cavity to form a water drainage surface, and a condensation pipe is arranged below the water drainage surface.

Preferably, the first blower comprises an air chamber and an ignition chamber, the ignition chamber is provided with a heating element, and air in the air chamber enters the blanking pipe from the hood after being heated by the heating element in the ignition chamber; the air chamber is also communicated with an air pipe.

Preferably, a one-way plate is hinged in the furnace body, the free end of the one-way plate inclines towards the top of the furnace body relative to the connecting end, and a slag falling hole is formed in the part, close to the connecting end, of the one-way plate.

Preferably, the wet-type washing unit comprises a tower body, an air inlet arranged at the lower part of the tower body, an air outlet arranged at the top of the tower body, an air inlet arranged at the upper part of the tower body, and an air outlet arranged at the bottom of the tower body; the top has laid alkali lye and has sprayed the piece in the tower body, alkali lye spray the piece by the tower body top to the direction of bottom include in proper order with the water pipe of inlet intercommunication, be used for holding solid alkali's holding pipe and shower head, be equipped with the through-hole between water pipe and the holding pipe, between holding pipe and the shower head respectively.

Preferably, vertical partition plates are sequentially arranged at the bottom and the top in the tower body, so that an S-shaped absorption channel is formed in an inner cavity of the tower body, the air inlet is formed in an inlet portion of the S-shaped absorption channel, and the air outlet and the liquid outlet are formed in an outlet portion of the S-shaped absorption channel.

Preferably, the bottom surface has laid in the tower body with the atomized liquid pipe of water pipe intercommunication, the intraductal ultrasonic atomization ware that is equipped with of atomized liquid, the one side that the atomized liquid pipe is close to the tower body inner chamber is equipped with a plurality of discharge holes.

Preferably, the temperature raising unit comprises an outer shell, an inner shell and a spiral air pipe arranged in the inner shell, a circulation channel is formed between the outer shell and the inner shell, and the spiral air pipe is provided with an inlet and an outlet which are communicated with the circulation channel; a temperature raising cavity connected with a steam outlet of the steam generating device is formed between the inner shell and the spiral air pipe, and a condensed water outlet connected with the liquid inlet is formed in the bottom of the temperature raising cavity.

The invention has the beneficial effects that:

1. the incineration method is adopted to treat the sludge, so that the water and organic matters in the sludge can be completely removed, all pathogens can be killed, and the volume of the sludge can be reduced to the maximum extent. The waste residue generated by burning is sent into a building material sintering device to be sintered into building materials, thereby achieving the effect of changing waste into valuable. The flue gas generated by incineration is sent into a flue gas purification device for treatment and then is discharged, so that the method is green and environment-friendly. Meanwhile, when the flue gas is purified, the dewatered water of the sludge is fully utilized and is used as a heat source of the temperature raising unit, and then the exchanged water with a certain temperature is used as an alkali solvent of the wet type washing unit, so that the solid alkali solubility is effectively improved, the heating requirement for improving the absorptivity in the wet type washing unit is reduced, and the energy is saved.

2. Meanwhile, a specially-made incineration device is adopted, on one hand, the sludge is uniformly thrown into the incineration device after being preheated and dried by utilizing the blanking pipe and the blast cap, and the throwing distance is farthest, so that the sludge is more sufficiently fluidized and combusted. On the other hand, the heat preservation shell and the air pipe are utilized to obtain hot air by utilizing incineration waste heat so as to further dry sludge, thereby improving the incineration efficiency, reducing the production of carbon monoxide in the incineration process, and being energy-saving and environment-friendly.

Drawings

FIG. 1 is a schematic flow diagram of a process for the integrated treatment of sludge from a municipal sewage plant;

FIG. 2 is a schematic view showing the construction of an incineration apparatus used in a sludge integrated treatment process in a municipal sewage plant;

FIG. 3 is a schematic diagram of a wet scrubbing unit used in a municipal sewage plant sludge integrated treatment process;

FIG. 4 is a schematic structural diagram of a temperature raising unit used in a comprehensive treatment process of sludge in a municipal sewage plant;

in the figure: a filter pressing device 1; the incinerator 2, the furnace body 21, the one-way plate 211, the blanking pipe 22, the hood 221, the first blower 23, the air chamber 231, the ignition chamber 232, the heat preservation shell 24, the second blower 25, the air pipe 26, the exhaust pipe 27, the dehumidifier 28 and the condensation pipe 29; a building material sintering device 3; a liquid nitrogen denitration unit 4; a quenching deacidification unit 5; a bag dust removal unit 6; the wet type washing unit 7, the tower body 71, the gas inlet 711, the gas outlet 712, the liquid inlet 713, the liquid outlet 714, the alkali liquor spray part 72, the water pipe 721, the accommodating pipe 722, the spray header 723, the atomized liquid pipe 724, the vertical partition plate 73, the inlet part 731 and the outlet part 732; the temperature raising unit 8, an outer shell 81, an inner shell 82 and a spiral air pipe 83; a steam generating device 9.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

A comprehensive treatment process for sludge of an urban sewage plant is shown in figure 1 and comprises the following steps:

(1) feeding the sludge into a filter pressing device 1 for dehydration to obtain dehydrated water and dehydrated sludge;

(2) the dehydrated sludge is sent into an incineration device 2 for incineration, the smoke generated by incineration is sent into a smoke purification device for evacuation, and the waste residue generated by incineration is sent into a building material sintering device 3; the flue gas purification device sequentially comprises a liquid nitrogen denitration unit 4, a quenching deacidification unit 5, a cloth bag dust removal unit 6, a wet washing unit 7 and a temperature raising unit 8;

(3) the dehydrated water is sent to a steam generating device 9, the generated steam is sent to a temperature raising unit 8, the steam is converted into condensed water after heat exchange, and the condensed water is sent to a wet type washing unit 7; the residual scale remaining in the steam generator is fed into the building material sintering device 3.

When the filter pressing device is used, firstly, the filter pressing device 1 is used for separating mud and water, and the dewatered mud enters the incineration device 2 for incineration so as to completely remove organic matters through high temperature, kill all pathogens and reduce the volume of the mud to the maximum extent. After incineration is finished, the residues can be sintered into building materials for reuse, and flue gas generated by incineration firstly enters a liquid nitrogen denitration unit 4, and nitrogen oxide is reduced by taking liquid nitrogen as a denitration reducing agent; then the high-temperature flue gas enters a rapid cooling deacidification unit 5 to be in turbulent contact with rapid cooling alkali liquor, on one hand, deacidification is carried out by the alkali liquor, on the other hand, the temperature of the flue gas is suddenly reduced, a secondary synthesis temperature section of harmful substance dioxin in the flue gas is avoided, and the dioxin is inhibited from being generated again; then the flue gas with the fine dust particles enters a bag-type dust removal unit 6, the smoke dust fly ash particles are filtered by a filter bag, and the flue gas is purified again; then the flue gas enters a wet deacidification unit 7 to absorb fine particles, acid gases, heavy metals and dioxin; the smoke is finally heated to be above the dew point through the temperature raising unit 8 and then discharged, so that the formation of visual white smoke is avoided. Meanwhile, because a large amount of dehydrated water is separated during sludge dehydration, the treatment process required by the dehydrated water purification is complex and the cost is high, so that the dehydrated water is used as a heat source of the temperature raising unit 8 and a solvent of the wet deacidification unit in the application to achieve the purpose of energy conservation.

The main processing unit in the process is an incineration unit, and because sludge cannot be completely dried through filter pressing, the dewatered sludge still contains certain moisture, in order to reduce the problem that a large amount of carbon monoxide is generated by sludge incineration due to the existence of the moisture and improve the incineration efficiency of the incineration device 2, as shown in fig. 2, the incineration device 2 comprises a furnace body 21 and a blanking pipe 22 which is arranged on the side wall of the furnace body 21 and communicated with an incineration cavity in the furnace body 21, and the included angle between the blanking pipe 22 and the furnace wall of the furnace body 21 is 40-50 degrees, in the embodiment, the included angle is 45 degrees; a plurality of air caps 221 communicated with the first air blower 23 are arranged in the blanking pipe 22, and the air caps 221 are vertically arranged on the pipe wall of the blanking pipe 22. Among them, the wind blown from the first blower 23 is preferably hot wind.

The air outlet of the hood 221 faces the incineration chamber in the furnace body 21, so that under the action of the first blower 23, the hot air coming out of the hood 221 further dries the dewatered sludge and enters the furnace body 21 at an upward 45-degree angle of the horizontal plane, and according to the principle of parabola, the 45-degree angle enables the dewatered sludge to be thrown farthest in the incineration chamber, so that the dewatered sludge is uniformly distributed in the incineration chamber to obtain sufficient fluidized combustion.

In order to fully utilize the incineration waste heat, a heat preservation shell 24 is sleeved outside the furnace body 21, and an air pipe 26 communicated with a second air blower 25 is arranged between the furnace body 21 and the heat preservation shell 24. Heat conducting oil is communicated between the outer wall of the air pipe 26, the heat insulating layer 24 and the furnace body 21. The air outlet of the air pipe 26 is arranged at the bottom of the incineration chamber of the furnace body 21, and the air outlet is communicated with an exhaust pipe 27 which is laid at the bottom of the furnace body 21 and is provided with a plurality of air holes at one surface close to the incineration chamber. The incineration waste heat is transferred to the air pipe 26 under the action of the heat conducting oil and heats the air in the air pipe 26 into hot air, and the hot air enters the furnace body 21 again from the bottom of the furnace body 21 under the action of the exhaust pipe 27 so as to further dry the dewatered sludge, thereby improving the incineration efficiency and reducing the generation of carbon monoxide in the incineration process.

Particularly, in the present embodiment, the wind pipe 26 is configured to have a serpentine shape, and the serpentine arrangement density is configured to gradually decrease from the bottom of the furnace to the top of the furnace according to the incineration condition in the furnace body 21, that is, the serpentine wind pipe 26 has the highest arrangement density at the position below the outlet of the blanking pipe 22, the arrangement density at the position with the equivalent height of the outlet of the blanking pipe 22 is moderate, and the arrangement density at the position above the outlet of the blanking pipe 22 is the lowest, so that the wind in the wind pipe 26 stays around the bottom of the furnace body for a longer time to be fully heated.

In order to further improve the combustion efficiency, the device can carry out secondary dehumidification on the air blown by the second air blower 25, and the dry air is matched with the dry sludge, so that the incineration efficiency can be improved to the maximum extent. The first dehumidification is realized under the action of a dehumidifier 28 arranged at the air inlet of the air duct 26, and the second dehumidification is realized because the center of one surface of the exhaust pipe 27 far away from the incineration chamber protrudes towards the incineration chamber to form a water discharge surface, and a condensing pipe 29 is arranged below the water discharge surface. In the embodiment, a drain hole provided with a valve is arranged at the joint of the drain surface and the side surface of the furnace body 21; when wind enters the exhaust pipe 27, the wind simultaneously contacts the condensation pipe 29 laid below the wind, in the embodiment, condensed water is introduced into the condensation pipe 29 to perform a condensation function, under the effect of the condensation pipe 29, water vapor in the wind is condensed into water drops and slides along the arc-shaped drainage surface, the water drops can be discharged from the drainage hole by opening the valve, and dry wind enters the furnace body 21 through the exhaust pipe 27 upwards, so that the drying degree of hot air sucked by the second air blower 25 and about to enter the hearth is further improved, and the incineration efficiency is improved to a greater extent.

In addition, in order to further use the hot air of the air duct 26, the first blower 23 includes an air chamber 231, and a slide plate having a through hole is installed at a communication position between the air chamber 231 and the air duct 26, so that the hot air in the air duct 26 enters the air chamber 231, thereby drying the sludge in the drop pipe 22. Meanwhile, through the sliding plate, the through hole on the sliding plate is matched with the opening of the air pipe 25, so that the air quantity entering the air chamber 231 can be changed.

In addition, the first blower 23 further comprises an ignition chamber 232, the ignition chamber 232 is provided with a heating element, and air in the air chamber 231 enters the blanking pipe from the hood 221 after being heated by the heating element in the ignition chamber 232. This is because when the incinerator 2 starts to incinerate, the sludge in the blanking pipe 22 needs to be dried by the hot air heated by the heating members, when the incinerator body 21 starts to incinerate to generate heat, the hot air can be obtained in the air pipe 26, at this time, due to the communication effect of the air pipe 26 and the air chamber 231, the hot air can enter the air chamber 231 and then heat the sludge in the blanking pipe 22, and at this time, the heating members can be closed.

Further, the furnace body 21 is internally hinged with a one-way plate 211, the free end of the one-way plate 211 inclines towards the top of the furnace body 21 relative to the connecting end, and the part of the one-way plate 211 close to the connecting end is provided with a slag falling hole. When sludge is thrown into the furnace body 21 and falls on the one-way plate 211 for incineration, the free end of the one-way plate 211 moves downwards under the action of the hinge joint due to the gravity action of the sludge at the beginning, but due to the inclined one-way plate 211, in the garbage incineration process, the burning ash generated by incineration moves towards the direction close to the furnace wall of the furnace body 21 under the guiding action of the one-way plate 211 and falls into the periphery of the hearth from the slag falling hole, so that the accumulation and blockage of the burning ash are prevented, and the middle part of the hearth is always kept in a proper combustion space. Meanwhile, because the gravity on the one-way plate 211 is reduced, the free end of the one-way plate 211 moves upwards under the resilience action of the one-way door structure, so that the sludge generates vibration under the inertia action, and the incineration is more uniform and sufficient.

Through the incinerator 2 of this application, can fully burn the processing to dehydration mud and reduce the production of burning in-process carbon monoxide as far as possible, nevertheless still contain a large amount of other pollutants in burning the flue gas, in order to reach the mesh that make full use of in this technology takes off water simultaneously, designed corresponding wet-type washing unit 7 and carry temperature unit 8 in the flue gas purification device.

As shown in fig. 3, the wet scrubbing unit 7 includes a tower body 71, an air inlet 711 disposed at a lower portion of the tower body 71, an air outlet 712 disposed at a top portion of the tower body 71, an air inlet 713 disposed at an upper portion of the tower body, and an air outlet 714 disposed at a bottom portion of the tower body; an alkali liquor spraying part 72 is laid on the top inside the tower body 71, the alkali liquor spraying part 72 sequentially comprises a water pipe 721 communicated with the liquid inlet 713, an accommodating pipe 722 for accommodating solid alkali and a spraying head 723 from the top to the bottom of the tower body 71, and through holes are respectively arranged between the water pipe 721 and the accommodating pipe 722 and between the accommodating pipe 722 and the spraying head 723. When in use, the flue gas enters the tower body 71 from the gas inlet 711 at the lower part and is in countercurrent contact with the alkali liquor to be absorbed.

Meanwhile, vertical partition plates 73 are sequentially arranged at the inner bottom and the inner top of the tower body 71, so that an inner cavity of the tower body 71 forms an S-shaped absorption channel, an air inlet 711 is arranged at an inlet part 731 of the S-shaped absorption channel, and an air outlet 712 and an liquid outlet 714 are arranged at an outlet part 732 of the S-shaped absorption channel. Thereby prolonging the flow path of the flue gas in the tower body 71, namely improving the contact time of the flue gas and the alkali liquor, and improving the absorption effect.

In addition, an atomized liquid pipe 724 communicated with the water pipe 721 is laid on the inner bottom surface of the tower body 71, an ultrasonic atomizer is arranged in the atomized liquid pipe 724, and a plurality of discharge holes are formed in one surface, close to the inner cavity of the tower body 71, of the atomized liquid pipe 724.

As shown in fig. 4, the temperature raising unit 8 includes an outer shell 81, an inner shell 82, and a spiral air pipe 83 installed in the inner shell 82, a circulation channel is formed between the outer shell 81 and the inner shell 82, and the spiral air pipe 83 is provided with an inlet and an outlet communicated with the circulation channel; a temperature raising cavity connected with a steam outlet of the steam generating device 9 is formed between the inner shell 82 and the spiral air pipe 83, and a condensed water outlet connected with the liquid inlet 713 is arranged at the bottom of the temperature raising cavity.

When the device is used, purified flue gas enters the spiral air pipe 83 from an air inlet pipe which is arranged at the lower part of the shell 81 and communicated with the spiral air pipe 83, is circularly heated by the temperature raising cavity under the action of the circulating channel, and is then emptied from an air outlet pipe which is arranged at the top of the shell 81 and communicated with the spiral air pipe 83.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A comprehensive treatment process for sludge of an urban sewage plant is characterized by comprising the following steps: the method comprises the following steps:

feeding the sludge into a filter pressing device (1) for dehydration to obtain dehydrated water and dehydrated sludge;

the dehydrated sludge is sent into an incineration device (2) for incineration, the smoke generated by incineration is sent into a smoke purification device for evacuation, and the waste residue generated by incineration is sent into a building material sintering device (3); the flue gas purification device sequentially comprises a liquid nitrogen denitration unit (4), a quenching and deacidifying unit (5), a cloth bag dust removal unit (6), a wet washing unit (7) and a temperature raising unit (8);

sending the dehydrated water into a steam generating device (9), sending the generated steam into a temperature raising unit (8), converting the steam into condensed water after heat exchange, and sending the condensed water into a wet washing unit (7); residual scale remained in the steam generating device is sent to a building material sintering device (3);

the incinerator (2) comprises an incinerator body (21) and a blanking pipe (22) arranged on the side wall of the incinerator body (21) and communicated with an incineration cavity in the incinerator body (21), and an included angle between the blanking pipe (22) and the incinerator wall of the incinerator body (21) is 40-50 degrees; a plurality of air caps (221) communicated with the first air blower (23) are installed in the blanking pipe (22), and the air caps (221) are vertically installed on the pipe wall of the blanking pipe (22); a one-way plate (211) is hinged in the furnace body (21), the free end of the one-way plate (211) inclines towards the top of the furnace body (21) relative to the connecting end, and a part of the one-way plate (211) close to the connecting end is provided with a slag falling hole; an exhaust pipe (27) is laid at the bottom of the furnace body (21).

2. The comprehensive treatment process for sludge of an urban sewage plant according to claim 1, which is characterized in that: a heat preservation shell (24) is sleeved outside the furnace body (21), an air pipe (26) communicated with a second air blower (25) is arranged between the furnace body (21) and the heat preservation shell (24), and heat conduction oil is communicated between the outer wall of the air pipe (26) and the heat preservation shell (24) as well as between the outer wall of the air pipe (26) and the furnace body (21); the air outlet of tuber pipe (26) sets up in the bottom that furnace body (21) burned the chamber, just the air outlet intercommunication has the blast pipe (27) of laying in furnace body (21) bottom, being close to the one side that burns the chamber and being equipped with a plurality of gas pockets.

3. The comprehensive treatment process for sludge of the municipal sewage plant according to claim 2, wherein the comprehensive treatment process comprises the following steps: the air inlet of tuber pipe (26) is equipped with dehumidifier (28), the center of the one side of burning the chamber is kept away from in blast pipe (27) forms the exhaust surface to burning the chamber protrusion, exhaust surface below is equipped with condenser pipe (29).

4. The comprehensive treatment process for sludge of the municipal sewage plant according to claim 2, wherein the comprehensive treatment process comprises the following steps: the first air blower (23) comprises an air chamber (231) and an ignition chamber (232), the ignition chamber (232) is provided with a heating element, and air in the air chamber (231) enters the blanking pipe from an air cap (221) after being heated by the heating element in the ignition chamber (232); the plenum (231) is also in communication with an air duct (26).

5. The comprehensive treatment process for sludge of an urban sewage plant according to claim 1, which is characterized in that: the wet type washing unit (7) comprises a tower body (71), an air inlet (711) arranged at the lower part of the tower body (71), an air outlet (712) arranged at the top of the tower body (71), a liquid inlet (713) arranged at the upper part of the tower body and a liquid outlet (714) arranged at the bottom of the tower body; an alkali liquor spraying part (72) is laid at the top in the tower body (71), the alkali liquor spraying part (72) sequentially comprises a water pipe (721) communicated with the liquid inlet (713), an accommodating pipe (722) used for accommodating solid alkali and a spray head (723) from the top to the bottom of the tower body (71), and through holes are respectively formed between the water pipe (721) and the accommodating pipe (722) and between the accommodating pipe (722) and the spray head (723).

6. The comprehensive treatment process for sludge of an urban sewage plant according to claim 5, wherein the comprehensive treatment process comprises the following steps: the inner bottom and the inner top of the tower body (71) are sequentially provided with vertical partition plates (73) so that an inner cavity of the tower body (71) forms an S-shaped absorption channel, the air inlet (711) is arranged at an inlet part (731) of the S-shaped absorption channel, and the air outlet (712) and the liquid outlet (714) are both arranged at an outlet part (732) of the S-shaped absorption channel.

7. The comprehensive treatment process for sludge of an urban sewage plant according to claim 5, wherein the comprehensive treatment process comprises the following steps: the bottom surface has laid in tower body (71) with atomizing liquid pipe (724) of water pipe (721) intercommunication, be equipped with the ultrasonic atomization ware in atomizing liquid pipe (724), the one side that atomizing liquid pipe (724) are close to tower body (71) inner chamber is equipped with a plurality of discharge holes.

8. The comprehensive treatment process for sludge of an urban sewage plant according to claim 5, wherein the comprehensive treatment process comprises the following steps: the temperature raising unit (8) comprises an outer shell (81), an inner shell (82) and a spiral air pipe (83) arranged in the inner shell (82), a circulating channel is formed between the outer shell (81) and the inner shell (82), and the spiral air pipe (83) is provided with an inlet and an outlet which are communicated with the circulating channel; a temperature raising cavity connected with a steam outlet of the steam generating device (9) is formed between the inner shell (82) and the spiral air pipe (83), and a condensed water outlet connected with the liquid inlet (713) is formed in the bottom of the temperature raising cavity.