Municipal sludge incineration system

Abstract

The utility model discloses a municipal sludge incineration system which comprises a dry sludge bin, an ignition furnace, a pre-combustion chamber, a suspended state incinerator, a collecting device, a heat exchange system and a waste gas treatment device. The pre-combustion chamber is connected with the suspended state incinerator and supplies heated air to the suspended state incinerator; dry sludge enters a suspended state incinerator to participate in combustion with heated air; the collecting device I is used for collecting incineration ash generated by combustion; the heat exchanger I is used for heating combustion-supporting air by using combustion flue gas discharged by the suspended state incinerator, and the combustion-supporting air is introduced into the suspended state incinerator to participate in combustion; the heat exchanger II heats cold air by utilizing excessive waste heat flue gas discharged by the heat exchanger I, so that waste heat utilization is realized; and the collecting device II is connected with a flue gas outlet of the heat exchanger II and is used for collecting fly ash in the flue gas. According to the invention, the incineration heat is in a closed-loop circulation loop, and redundant heat is also recycled, so that the use efficiency of the heat is greatly improved, and the energy consumption is reduced; ash generated by the system is collected in a multi-stage mode, tail gas is effectively treated, and environmental pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of sludge treatment, and in particular relates to a municipal sludge incineration system. Background Art

[0002] Sludge contains organic matter, carcinogenic microorganisms, pathogens and toxic heavy metals, which must be properly handled. In the existing technology, drying and incineration is an important way to dispose of municipal sludge, which can achieve sludge reduction, harmlessness and environmental protection. Drying and incineration refers to fully burning the combustible components in the sludge at high temperature, leaving only a small amount of ash, and then removing harmful pollutants in the sludge. In addition, the dried sludge is a low calorific value fuel, and the ash after incineration will not produce secondary pollution. Therefore, sludge incineration is widely used.

[0003] In the process of sludge incineration, the current bottleneck is that the incineration equipment consumes a lot of fuel, generates high energy consumption, and cannot effectively treat dust and harmful gases completely harmlessly, but directly discharges them into the air. This practice not only pollutes the air and causes environmental problems, but also poses a serious threat to human health. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an environmentally friendly and energy-saving municipal sludge incineration system, which overcomes the shortcomings of the existing municipal sludge drying equipment, realizes efficient energy utilization through the heat exchange system, maintains the spontaneous combustion operation of the sludge, saves energy consumption, realizes sludge reduction, and also realizes harmless treatment of sludge incineration through a closed incinerator and a multi-stage collection device.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect of the present invention, a municipal sludge incineration system is provided, comprising a dry sludge bin, an ignition furnace, a pre-combustion chamber, a suspended incinerator, a collecting device, a heat exchange system and an exhaust gas treatment device; the collecting device comprises a collecting device 1 and a collecting device 2, and the heat exchange system comprises a heat exchanger 1 and a heat exchanger 2;

[0007] The ignition furnace supplies a heat source to the precombustion chamber, and the heat source is used to preheat the room temperature air in the precombustion chamber to obtain preheated air. Heat is continuously introduced into the precombustion chamber to continuously heat the preheated air, thereby obtaining heated air. The precombustion chamber is connected to the suspended incinerator to supply heated air thereto; dry sludge enters the suspended incinerator to participate in combustion with the heated air; the collecting device 1 is connected to the flue gas outlet of the suspended incinerator to collect the incineration ash produced by the combustion; the heat exchanger 1 is connected to the flue gas outlet of the collecting device 1, and the combustion flue gas discharged from the suspended incinerator is used to heat the combustion-supporting air; the combustion-supporting air outlet of the heat exchanger 1 is connected to the inlet of the precombustion chamber, and the combustion-supporting air is then introduced into the suspended incinerator to participate in combustion;

[0008] The second heat exchanger is connected to the flue gas outlet of the first heat exchanger, and uses the excess hot flue gas discharged from the first heat exchanger to heat the cold air, thereby realizing waste heat utilization; the second collection device is connected to the flue gas outlet of the second heat exchanger, and collects fly ash in the flue gas.

[0009] In one embodiment, the dry sludge bin is connected to the feed inlet of the suspended incinerator through a metering device.

[0010] In one embodiment, a temperature monitoring device is provided at the combustion air inlet of the pre-combustion chamber. When the sludge combustion can be maintained by the combustion air, a sludge incineration self-circulation is formed and the ignition furnace is closed to supply the heat source.

[0011] In one embodiment, the pre-combustion chamber is a vertical cylindrical structure, which is arranged downstream of the suspended incinerator and uses the heat source provided by the ignition furnace to preheat the normal temperature air;

[0012] The suspended incinerator is a cylindrical cavity, the bottom inlet of which is connected to the pre-combustion chamber, through which heating air or combustion-supporting air passes, and the feed inlet is located on the lower side wall. The dry sludge is incinerated in the cavity, and the dry sludge is in a suspended combustion state.

[0013] In one embodiment, the collecting device 1 includes a separator, a cyclone and a sludge ash bin; the inlet of the separator is connected to the flue gas outlet of the suspended incinerator, the solid phase outlet is connected back to the dry sludge inlet of the suspended incinerator, and the gas phase outlet is connected to the inlet of the cyclone; the cyclone performs gas-solid separation on the combustion flue gas to obtain incineration ash, and its solid phase outlet is connected to the sludge ash bin, and the gas phase outlet is the flue gas outlet of the collecting device 1.

[0014] In one embodiment, the second collection device includes a dust collector and a fly ash bin. The dust collector removes dust from the flue gas exiting the second heat exchanger to obtain fly ash. The fly ash bin is connected to the solid phase outlet of the dust collector to store the obtained fly ash. The dust collector is connected to an induced draft fan, which is used to induce air for the entire system.

[0015] In one embodiment, the combustion flue gas discharged from the second heat exchanger after secondary heat exchange is effectively filtered and dusted by the dust collector before being discharged.

[0016] A second aspect of the present invention provides a municipal sludge incineration method, which is implemented based on the municipal sludge incineration system described in the first aspect, wherein a pre-combustion chamber provided with a heat source by an ignition furnace heats room temperature air to obtain preheated air, and the heated air is continuously heated to obtain heated air, which is then introduced into a suspended incinerator to incinerate dry sludge;

[0017] The combustion flue gas discharged from the suspended incinerator is collected by the collection device for settling and ash collection and gas-solid separation, and the incineration ash produced by the combustion is collected. The combustion flue gas from the collection device enters the heat exchanger to heat the cold air to obtain combustion-supporting air and is sent to the pre-combustion chamber, and then re-enters the suspended incinerator to participate in the combustion;

[0018] The flue gas from the first heat exchanger enters the second heat exchanger to heat the cold air for waste heat utilization. The flue gas discharged from the second heat exchanger is collected by the second dust collecting device to collect fly ash in the flue gas.

[0019] In one embodiment, the furnace temperature of the suspended incinerator is controlled at 850-950°C, the cold air is room temperature air, the temperature of the combustion flue gas entering heat exchanger one is 850-950°C, the temperature of the combustion air entering the pre-combustion chamber is 330-550°C, the temperature of the flue gas entering heat exchanger two is 400-500°C, the temperature of the flue gas after heat exchange in heat exchanger two is 60-120°C, and the temperature of the residual hot flue gas after passing through the waste heat utilization device is 70-90°C.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1) The present invention utilizes the high-temperature combustion flue gas generated by sludge incineration in multiple stages and sets up a two-stage heat exchange system. The heat of the high-temperature combustion flue gas returns to the incineration process after passing through the heat exchange system to form a sludge incineration self-circulation, which effectively reduces the energy consumption of sludge incineration and makes full use of the recovered heat, thereby improving energy utilization.

[0022] 2) The present invention provides a two-stage collection device to facilitate the effective classification, collection and treatment of dust generated during sludge incineration. The residue rate of sludge incineration is low, which prevents direct discharge into the air to cause environmental pollution, and the operation is safe and reliable.

[0023] 3) The present invention has the significant advantages of reduction, stabilization and harmlessness. The furnace temperature of the incinerator can ensure that the dry sludge can be fully burned under this condition to avoid the production of dioxins, and the waste gas treatment device makes all harmful substances in the sludge during the drying and incineration process be completely decomposed, and the polluted waste gas is effectively treated.

[0024] In summary, the present invention has many advantages and use values. It has great improvements in both structure and function, has significant progress in technology, and has good practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the present invention.

[0026] Figure 2 This is a schematic diagram of the results of Example 1 of the present invention.

[0027] 1. Ignition furnace, 2. Precombustion chamber, 3. Suspended incinerator, 4. Metering device, 5. Dry sludge bin, 6. Sludge ash bin, 7. Separator, 8. Cyclone, 9. Heat exchanger 1, 10. Heat exchanger 2, 11. Dust collector, 12. Fly ash bin, 13. Induced draft fan, 14. Collecting device 1, 15. Collecting device 2. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

[0029] Municipal sludge incineration is a common sludge treatment method, which can effectively reduce the amount of sludge and make it harmless. However, as mentioned above, the existing technology has many problems such as high energy consumption, pollutant emissions, and difficulty in handling ash. To this end, the present invention provides a municipal sludge incineration system, such as Figure 1 As shown, it mainly includes dry sludge bin 5, ignition furnace 1, pre-combustion chamber 2, suspended incinerator 3, collection device, heat exchange system and waste gas treatment device, etc. Among them, the collection device includes collection device 1 14 and collection device 2 15, and the heat exchange system includes heat exchanger 1 9 and heat exchanger 2 10.

[0030] The function of the ignition furnace 1 is to supply a heat source to the pre-combustion chamber 2. The pre-combustion chamber 2 uses the heat source to preheat the room temperature air introduced therein to obtain preheated air. By continuously introducing heat into the pre-combustion chamber 2, the preheated air can be continuously heated to obtain heated air. The pre-combustion chamber 2 is connected to the suspended incinerator 3, and the obtained heated air is supplied to the suspended incinerator 3. The dry sludge from the dry sludge bin 5 is also sent to the suspended incinerator 3 after being weighed by the metering device 4, and participates in combustion with the heated air.

[0031] In the present invention, the flue gas outlet of the suspended incinerator 3 receives the collecting device 14, and the function of the collecting device 14 is to collect the incineration ash produced by the combustion in the suspended incinerator 3, that is, the first-level recovery of the present invention. The flue gas outlet of the collecting device 14 is connected to the heat exchanger 9, and the function of the heat exchanger 9 is to use the combustion flue gas discharged from the suspended incinerator 3 to heat the combustion air. The combustion air outlet of the heat exchanger 9 is connected to the inlet of the pre-combustion chamber 2, that is, the heated combustion air is sent to the pre-combustion chamber 2, and is introduced into the suspended incinerator alone or merged with the aforementioned heated air to participate in the combustion.

[0032] The flue gas outlet of heat exchanger 1 9 is connected to heat exchanger 2 10, and the function of heat exchanger 2 10 is to use the excess hot flue gas discharged from heat exchanger 1 9 to heat the cold air, thereby realizing the waste heat utilization. The flue gas outlet of heat exchanger 2 10 receives collection device 2 15, and the function of collection device 2 15 is to collect fly ash in the flue gas, i.e., the second-level recovery of the present invention.

[0033] According to the present invention, after the ignition furnace 1 is started, the air is heated, and the pre-combustion chamber 2 is continuously heated to obtain heated air. The heated air and the measured dry sludge enter the suspended incinerator 3 to participate in combustion. The incineration ash generated by the sludge incineration is collected by the collecting device 14. The combustion flue gas discharged from the suspended incinerator 3 is absorbed by the heat exchanger 19 to heat and obtain combustion-supporting air. The combustion-supporting air is then introduced into the suspended incinerator 3 to participate in combustion. The heat exchanger 10 uses the combustion flue gas discharged from the heat exchanger 9 for secondary heat exchange. The heat after heat exchange is introduced into the waste heat utilization device for further utilization, and the fly ash is collected by the collecting device 15. The present invention uses the heat exchanger 19 to exchange the combustion heat generated by the suspended incinerator 3. The heat after heat exchange is then supplied to the pre-combustion chamber 2, and then participates in combustion to form a closed-loop circulation circuit. The excess heat is recovered by the heat exchanger 10 and enters the waste heat utilization device for utilization, which greatly improves the efficiency of heat utilization and saves energy consumption. In addition, the ash generated by the system is collected at multiple levels to reduce environmental pollution.

[0034] According to the process of this system, the steps are as follows:

[0035] The pre-combustion chamber 2 provided with heat source by the ignition furnace 1 heats the air at room temperature to obtain preheated air, and the heated air is continuously heated to obtain heated air, which is introduced into the suspension incinerator 3 to incinerate the dry sludge. For example, the ignition furnace 1 can be in the form of side burner type, top burner type, multi-slit type, double oblique belt type, hot air ignition type, hot air sintering type, low calorific value gas type, etc. In order to meet the incineration of dry sludge, the furnace temperature of the suspension incinerator 3 should be controlled at 850-950°C.

[0036] The combustion flue gas discharged from the suspended incinerator 3 is settled and ash is collected and separated by gas and solid through a collecting device 14, and the incineration ash produced by the combustion is collected. The combustion flue gas from the collecting device 14 enters a heat exchanger 9 to heat the cold air to obtain combustion-supporting air. The combustion-supporting air can be sent to the pre-combustion chamber 2, and then passed into the suspended incinerator 3 alone to participate in the combustion, or sent to the pre-combustion chamber 2, and then mixed with the heated air to pass into the suspended incinerator 3 to participate in the combustion, or not sent to the pre-combustion chamber 2 but directly sent to the suspended incinerator 3 to participate in the combustion.

[0037] The flue gas from the heat exchanger 19 enters the heat exchanger 210 to heat the cold air for waste heat utilization. The flue gas discharged from the heat exchanger 210 is collected by the dust collecting device 215 to collect the fly ash in the flue gas. The cold air heated in the heat exchanger 19 and the heat exchanger 210 is normal temperature air. The temperature of the combustion flue gas discharged from the collection device 14 to the heat exchanger 19 is approximately between 850 and 950°C, while the temperature of the combustion air entering the pre-combustion chamber 2 is approximately between 330 and 550°C. The temperature of the flue gas discharged to the heat exchanger 210 is approximately between 400 and 500°C. After the heat exchange in the heat exchanger 210, the flue gas temperature drops to 60 to 120°C. The temperature of the residual hot flue gas after passing through the waste heat utilization device is approximately 70 to 90°C.

[0038] It can be seen that the present invention can perform multi-stage waste heat utilization and purification treatment on the high-temperature combustion flue gas generated by sludge incineration, and the heat of the high-temperature combustion flue gas is reused as a heat source in the sludge combustion process, effectively reducing the system energy consumption and improving the heat utilization rate.

[0039] There are two reasons why a two-stage dust collection device is provided in the municipal sludge incineration system of the present invention. First, since the temperature of the incineration ash is too high, one-time collection will cause the dust collection bag to be overheated and damaged, causing great damage to the collection device, so it is difficult to collect it in one go; second, because fly ash is a hazardous waste, it should be collected and treated separately, otherwise it will cause harm to the environment.

[0040] In one embodiment of the present invention, the dry sludge bin 5 is connected to the feed port of the suspended incinerator 3 through the metering device 4, and the dry sludge bin 5 is provided to store excess dry sludge, so as to cope with the sludge combustion conditions under different production. The metering device 4 is used to accurately meter the dry sludge fed into the suspended incinerator 3, so as to adjust the amount of heating air and / or combustion air according to the heat of the heating air and / or combustion air, or to adjust the flow rate of the heating air and / or combustion air according to the amount of dry sludge. For example, the metering device 4 can be a belt metering scale.

[0041] In one embodiment of the present invention, heat is continuously introduced into the pre-combustion chamber 2 to continuously heat the preheated air, thereby obtaining heated air. This part of heated air can be introduced from the bottom of the suspended incinerator 3, so that the material is in a suspended state in the suspended incinerator 3, which is more conducive to the full reaction. The sludge incineration system of the present invention can be used flexibly. When the calorific value of the sludge reaches the ignition point of the sludge spontaneous combustion, the combustion air required for the sludge incineration can be provided by the combustion-supporting air after heat exchange. Specifically, a temperature monitoring device can be provided at the combustion-supporting air inlet of the pre-combustion chamber 2. When the sludge combustion can be maintained by the combustion-supporting air alone, it means that the sludge incineration self-circulation can be formed. At this time, the ignition furnace 1 can be closed to supply the heat source, thereby reducing energy consumption.

[0042] In one embodiment of the present invention, the pre-combustion chamber 2 is a vertical cylindrical structure, which is arranged downstream of the suspended incinerator 3, and uses the heat source provided by the ignition furnace 1 to preheat the normal temperature air, which can improve the combustion efficiency of the suspended incinerator 3, so that heat can be stably input into the system, and the ignition furnace 1 is connected to its lower part. The vertical cylindrical structure is conducive to the rise of hot air flow and the uniform mixing of fuel. Since the pre-combustion chamber 2 can preheat the air entering the incinerator, the temperature fluctuation inside the incinerator can be reduced, ensuring a stable supply of heat energy.

[0043] In one embodiment of the present invention, the suspended incinerator 3 is a cylindrical cavity, which is conducive to achieving uniform suspension and combustion of materials. Its bottom inlet is connected to the pre-combustion chamber 2, and heated air or combustion-supporting air is passed through it. The feed inlet is located on its lower side wall. It burns dry sludge, and the dry sludge is in a suspended combustion state therein, which means that the material is dispersed into tiny particles under the action of high-temperature gas, fully contacted with oxygen, and can be fully burned. The suspended combustion state helps to increase the combustion rate, ensure that the organic matter in the dry sludge is fully oxidized and decomposed, and reduce the generation of harmful gases and solid residues. The generated combustion flue gas and ash are passed into the collection device 14, and the collection device 14 is used to preliminarily remove particulate matter and harmful substances in the flue gas, purify the flue gas to meet environmental emission standards, and the collected ash can be treated as waste, or further recycled according to the composition.

[0044] In one embodiment of the present invention, reference Figure 2As shown, the collecting device 14 is arranged between the suspended incinerator 3 and the heat exchanger 9, and its function is to collect the discharged incineration ash, and it mainly includes a separator 7, a cyclone 8 and a sludge ash bin 6. The inlet of the separator 7 is connected to the flue gas outlet of the suspended incinerator 3, the solid phase outlet is connected back to the dry sludge inlet of the suspended incinerator 3, and the gas phase outlet is connected to the inlet of the cyclone 8; the cyclone 8 performs gas-solid separation on the combustion flue gas to obtain incineration ash, and its solid phase outlet is connected to the sludge ash bin 6, and the gas phase outlet is the flue gas outlet of the collecting device 14. The combustion products discharged from the suspended incinerator 3 are first settled in the collecting device 14 for ash collection and gas-solid separation. The heat exchanger 9 uses the combustion flue gas discharged from the suspended incinerator 3 to heat the cold air to obtain combustion air, and the combustion air is then supplied to the suspended incinerator 3, forming a circulation path for heat to circulate between the pre-combustion chamber 2, the suspended incinerator 3, and the heat exchanger 9. Heat exchanger 2 10 utilizes the combustion flue gas discharged from heat exchanger 1 9 after the first-stage heat exchange to heat the cold air, thereby performing the second-stage heat exchange.

[0045] Furthermore, the heat exchanger 10 is connected to a waste heat utilization device, and the cold air is passed into the waste heat utilization device after the secondary heat exchange, so that this part of energy can be effectively utilized.

[0046] In one embodiment of the present invention, reference Figure 2 As shown, the collecting device 2 15 is arranged after the heat exchanger 2 10, and is used to recover the finer fly ash discharged from the system. It mainly includes a dust collector 11 and a fly ash bin 12. The dust collector 11 removes dust from the flue gas of the heat exchanger 2 10 to obtain fly ash. The fly ash bin 12 receives the solid phase outlet of the dust collector 11 and stores the obtained fly ash. The dust collector 11 is connected to an induced draft fan 13, and the induced draft fan 13 is used to induce air for the entire system. The combustion flue gas discharged from the heat exchanger 2 10 after the secondary heat exchange is effectively filtered and dusted by the dust collector 11 before being discharged. Since the sludge in the system is completely burned, no toxic and harmful substances such as dioxins are generated.

[0047] The combustion flue gas of the present invention is discharged after being purified by a waste gas treatment device after two-stage dust removal, and the discharged waste gas fully meets the emission standards, thus avoiding waste pollution of the atmosphere and protecting the environment.

[0048] In such Figure 2 In the specific structural form shown, in the municipal sludge incineration system of the present invention, the feed end of the suspended incinerator 3 is connected by the metering device 4 after the dry sludge bin 5, and the suspended incinerator 3 is provided with a separator 7 for screening, and the separator 7 is connected to the cyclone 8, and the incineration ash after the dust removal of the combustion flue gas is input into the sludge ash bin, and the cyclone 8 is connected to the heat exchanger 1 9 and the heat exchanger 2 10 in sequence, and the heat exchanger 2 10 is connected to the dust collector 11, and the system fly ash is input into the fly ash bin 12 after the dust removal by the dust collector 11, and the dust collector 11 is connected to the induced draft fan 13. Its specific operation steps are as follows:

[0049] The dry sludge stored in the dry sludge bin 5 is weighed by the metering device 4 and transported to the suspended incinerator 3 for incineration. Before incineration, the pre-combustion chamber 2 provided with heat source by the ignition furnace 1 can preheat the room temperature air first, and then pass it into the suspended incinerator 3 for preheating. The temperature of the suspended incinerator 3 is generally controlled at 850-950°C. After the reaction, the incompletely burned materials will be screened by the separator 7 and will enter the suspended incinerator 3 again to continue burning. The ash generated during the incineration process is collected by the cyclone 8 and stored in the sludge ash bin 6. The heat exchanger 9 utilizes the sludge The combustion flue gas generated by incineration heats the combustion air, and the combustion air circulates into the suspended incinerator 3 to participate in the combustion, forming a circulation path for heat to circulate between the incineration system and the heat exchange system. When the circulation path is stable, the system can be separated from the ignition furnace 2 to supply the heat source for self-circulating incineration. The heat exchanger 10 performs secondary heat exchange on the combustion flue gas discharged from the heat exchanger 9 and after the primary heat exchange. The flue gas after the heat exchange of the heat exchanger 10 is then introduced into the waste heat utilization device for utilization; the dust collector 11 removes the dust-containing exhaust gas and discharges it after meeting the standards. The fly ash generated is stored in the fly ash bin 12.

[0050] In summary, the sludge incineration system of the present invention utilizes a suspended incinerator to incinerate the sludge that has been weighed by a metering device from a dry sludge bin; wherein a pre-combustion chamber provided with a heat source by an ignition furnace is provided before the suspended incinerator, the pre-combustion chamber preheats the incineration system in advance, and the incineration ash generated by the suspended incinerator is collected by a collecting device 14; a heat exchanger 19 and a heat exchanger 210 are provided after the suspended incinerator to exchange heat with the combustion flue gas from the incinerator; the heat exchanger 19 is connected to the pre-combustion chamber to form a closed circulation loop for heating the pre-combustion chamber, the heat exchanger 210 recovers excess heat of the heat exchanger 19, and passes the heat into a waste heat utilization device for reuse; a collecting device and a waste gas treatment device are provided after the heat exchanger 10, the collecting device 215 collects the residual fly ash in the system, and the waste gas treatment device purifies the waste gas.

[0051] The above examples are not exhaustive of the preferred embodiments of the present invention, and the device of the present invention can also have many forms.

[0052] The above description is only a preferred example of the present invention and does not constitute any form of limitation on the present invention. Although the present invention has been disclosed as a preferred example as above, it is not used to limit the present invention. Any technician familiar with the present invention can make any slight changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A municipal sludge incineration system, characterized in that: It comprises a dry sludge bin (5), an ignition furnace (1), a pre-combustion chamber (2), a suspended incinerator (3), a collecting device, a heat exchange system and an exhaust gas treatment device; the collecting device comprises a collecting device 1 (14) and a collecting device 2 (15), and the heat exchange system comprises a heat exchanger 1 (9) and a heat exchanger 2 (10); The ignition furnace (1) supplies a heat source to the pre-combustion chamber (2), and the heat source is used to preheat the room temperature air in the pre-combustion chamber (2) to obtain preheated air. The pre-combustion chamber (2) continuously introduces heat to continuously heat the preheated air, thereby obtaining heated air. The pre-combustion chamber (2) is connected to the suspended incinerator (3) to supply heated air thereto; the dry sludge enters the suspended incinerator (3) and participates in combustion with the heated air; the collecting device (14) is connected to the flue gas outlet of the suspended incinerator (3) to collect the incineration ash produced by the combustion; the heat exchanger (9) is connected to the flue gas outlet of the collecting device (14), and the combustion flue gas discharged from the suspended incinerator (3) is used to heat the combustion-supporting air; the combustion-supporting air outlet of the heat exchanger (9) is connected to the inlet of the pre-combustion chamber (2), and the combustion-supporting air is then introduced into the suspended incinerator to participate in combustion; The second heat exchanger (10) is connected to the flue gas outlet of the first heat exchanger (9), and utilizes the excess hot flue gas discharged from the first heat exchanger (9) to heat the cold air, thereby realizing waste heat utilization; the second collection device (15) is connected to the flue gas outlet of the second heat exchanger (10), and collects fly ash in the flue gas; The pre-combustion chamber (2) is a vertical cylindrical structure, which is arranged downstream of the suspended incinerator (3) and uses the heat source provided by the ignition furnace (1) to preheat the air at normal temperature; The suspended incinerator (3) is a cylindrical cavity, the bottom inlet of which is connected to the pre-combustion chamber (2) and passes heating air or combustion-supporting air. The feed inlet is located on the lower side wall of the incinerator, and the dry sludge is incinerated therein, and the dry sludge is in a suspended combustion state.

2. The municipal sludge incineration system according to claim 1, characterized in that: The dry sludge bin (5) is connected to the feed inlet of the suspended state incinerator (3) via a metering device (4).

3. The municipal sludge incineration system according to claim 1, characterized in that: A temperature monitoring device is provided at the combustion air inlet of the pre-combustion chamber (2). When the sludge combustion can be maintained by the combustion air, a sludge incineration self-circulation is formed and the ignition furnace (1) is closed to supply the heat source.

4. The municipal sludge incineration system according to claim 1, characterized in that: The collecting device (14) comprises a separator (7), a cyclone (8) and a sludge ash bin (6); the inlet of the separator (7) is connected to the flue gas outlet of the suspended incinerator (3), the solid phase outlet is connected back to the dry sludge inlet of the suspended incinerator (3), and the gas phase outlet is connected to the inlet of the cyclone (8); the cyclone (8) performs gas-solid separation on the combustion flue gas to obtain incineration ash, and its solid phase outlet is connected to the sludge ash bin (6), and the gas phase outlet is the flue gas outlet of the collecting device (14).

5. The municipal sludge incineration system according to claim 1, characterized in that: The second collecting device (15) comprises a dust collector (11) and a fly ash bin (12). The dust collector (11) removes dust from the flue gas exiting the second heat exchanger (10) to obtain fly ash. The fly ash bin (12) is connected to the solid phase outlet of the dust collector (11) to store the obtained fly ash. The dust collector (11) is connected to an induced draft fan (13) behind it, and the induced draft fan (13) is used for induced air for the entire system.

6. The municipal sludge incineration system according to claim 5, characterized in that: The combustion flue gas discharged from the second heat exchanger after the secondary heat exchange is effectively filtered and dusted by the dust collector (11) before being discharged.

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