A system and treatment method for increasing the proportion of organic waste co-disposal in cement kilns

Abstract

The present invention discloses a system and a treatment method for improving the proportion of organic waste co-treatment in a cement kiln. The system includes a decomposition furnace, a tertiary air duct connected to the decomposition furnace, a high-temperature pre-treatment system, a residue cooling and conveying system, a waste heat power generation system connected to the residue cooling and conveying system, and a waste pre-treatment system; the waste outlet of the waste pre-treatment system is connected to the waste inlet of the high-temperature pre-treatment system, the combustion air inlet of the high-temperature pre-treatment system is simultaneously connected to the waste gas outlet of the waste pre-treatment system and the branch pipe of the tertiary air duct, the flue gas outlet of the high-temperature pre-treatment system is connected to the decomposition furnace, the residue outlet of the high-temperature pre-treatment system is connected to the inlet of a material distribution device, and the outlet of the material distribution device is simultaneously connected to the decomposition furnace and the residue cooling and conveying system. The system of the present invention improves the adaptability and treatment ratio of cement kilns to organic waste, and meets the comprehensive and integrated treatment requirements of regional organic waste.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste disposal, and in particular relates to a system and a treatment method for increasing the proportion of organic waste co-disposal in a cement kiln. Background Art

[0002] Most of the existing cement kiln co-treatment process devices are used to treat a single type of waste, such as domestic garbage, sludge, straw, etc. A few processes that can treat multiple types of waste also use collective treatment, that is, different wastes are pre-treated and directly added to different parts of the cement kiln system. For example, Chinese patent application CN 208901406U provides a system for co-treatment of hazardous waste in a cement kiln. The system includes a solid hazardous waste treatment unit, a semi-solid hazardous waste treatment unit and a liquid hazardous waste treatment unit. The solid hazardous waste treatment unit, the liquid hazardous waste treatment unit and the semi-solid hazardous waste treatment unit work independently and directly send the hazardous waste to the cement line for incineration treatment; the solid hazardous waste treatment unit can also work in conjunction with the liquid and semi-solid hazardous waste treatment units, and the mixed hazardous waste is pumped to the cement kiln for incineration treatment. This method is greatly limited by the material composition, and there are problems such as low treatment capacity and large treatment volume, which affects the stability of the cement burning system and reduces the quality of cement clinker. Although cement kiln co-treatment technology can be designed specifically for wastes with basically determined treatment components, it cannot be quickly and dynamically adjusted in view of the reality that there are many types of wastes and their components vary greatly. It has poor adjustability and it is difficult to achieve the goal of simultaneously disposing of a large proportion of multiple types of wastes, which in turn restricts the co-treatment capacity and scale of cement kiln co-treatment projects.

[0003] Chinese patent application CN102607044A discloses an incineration method for disposing multi-variety and multi-phase wastes, which belongs to the field of waste treatment methods, including passing the waste to be incinerated from top to bottom in the incineration device, and at the same time, the high-temperature wind passing through the incineration device from top to bottom ignites and incinerates the waste to be incinerated and carries the incineration products out of the incineration device; the waste entering the incineration device stays at different height positions of the incineration device for incineration, and is controllably incinerated at each height position for a specified time before exiting the incineration device. The invention is an incineration method that can simultaneously dispose of three or more types of multi-phase wastes (industrial waste residues, waste liquids, urban domestic garbage, sewage plant sludge), and can complete integrated disposal. In the prior art, in order to increase the proportion of organic wastes co-disposed of by cement kilns, it is necessary to pre-treat the organic waste at high temperature, such as using external pre-treatment equipment such as hot plate furnaces and step furnaces.

[0004] However, the combustion air of the pre-treatment equipment of this type of technology is generally provided by tertiary air. However, the temperature of tertiary air is relatively high. When the amount and calorific value of the organic waste to be treated change, the temperature of the pre-treatment equipment will also fluctuate, and the temperature of the flue gas entering the decomposition furnace will also fluctuate, affecting the stable operation of the cement kiln clinker burning system. In order to control the temperature, the method of adding flammable materials (such as coal powder) and non-flammable materials (such as raw materials) is generally adopted. This method has the problems of slow response to the adjustment speed, low control accuracy, and occupying the volume of the pre-treatment equipment. In addition, when the ash content of the organic waste is large and contains a high content of elements that affect the quality of the clinker (such as P, Cl, heavy metal elements, etc.), the conventional high-temperature pre-treatment equipment will directly send the ash into the decomposition furnace, which will affect the quality of the clinker, and then there will be a problem of insufficient disposal of organic waste. Summary of the invention

[0005] Purpose of the invention: In order to solve the problems of the prior art, the present invention provides a system and a treatment method for increasing the proportion of organic waste co-disposal in cement kilns. The system of the present invention improves the adaptability and disposal ratio of organic waste and meets the comprehensive and integrated disposal requirements of regional organic waste.

[0006] Technical solution: The system described in the present invention is a system for improving the proportion of organic waste co-treatment in cement kilns, comprising a decomposition furnace, a tertiary air duct connected to the decomposition furnace, a high-temperature pre-treatment system, a residue cooling and conveying system, a waste heat power generation system connected to the residue cooling and conveying system, and a waste pre-treatment system; the waste outlet of the waste pre-treatment system is connected to the waste inlet of the high-temperature pre-treatment system, the combustion air inlet of the high-temperature pre-treatment system is simultaneously connected to the waste gas outlet of the waste pre-treatment system and the branch of the tertiary air duct, the flue gas outlet of the high-temperature pre-treatment system is connected to the decomposition furnace, the residue outlet of the high-temperature pre-treatment system is connected to the inlet of a material distribution device, and the outlet of the material distribution device is simultaneously connected to the decomposition furnace and the residue cooling and conveying system.

[0007] The branch pipe delivers the tertiary air to the combustion air inlet of the high-temperature pre-treatment system, and a first air volume regulating valve is arranged on the pipeline of the branch pipe.

[0008] The high-temperature pre-treatment system includes a sealed feeding device, a waste liquid spray gun, a burner and a multi-phase waste pre-combustion furnace; the inlet of the multi-phase waste pre-combustion furnace is respectively provided with a first inlet for feeding solid waste, a second inlet for feeding semi-solid waste, a third inlet for feeding low calorific value liquid waste and a fourth inlet for feeding high calorific value liquid waste and ignition and combustion assistance. The first inlet is provided with a sealed feeding device for feeding solid waste, the third inlet is provided with a waste liquid spray gun, and the fourth inlet is provided with a burner; the outlet of the multi-phase waste pre-combustion furnace is connected to the inlet of the material distribution device.

[0009] The outlet of the material distribution device is respectively provided with a first passage connected to the residue cooling and conveying system and a second passage connected to the decomposition furnace, a first valve is provided on the first passage, and a second valve is provided on the second passage.

[0010] The waste pretreatment system includes a pretreatment workshop, the waste outlet of the pretreatment workshop is connected to the inlet of the multi-phase waste precombustion furnace, and the waste gas outlet of the pretreatment workshop is provided with a fan, and the outlet of the fan is respectively connected to the combustion air inlet of the multi-phase waste precombustion furnace and the emergency deodorization system.

[0011] The outlet of the fan is connected to the combustion air inlet of the multi-phase waste precombustion furnace through the exhaust gas branch pipe, a second air volume regulating valve is arranged on the exhaust gas branch pipe, and a third air volume regulating valve is arranged between the fan and the emergency deodorization system.

[0012] The residue cooling and conveying system comprises a residue cooler, a residue bin, a gate valve and a conveyor.

[0013] The waste heat power generation system comprises a circulating water pump, a water-to-water heat exchanger, a deaerator and a condensate pump connected to the cooling pipeline of the residue cooler.

[0014] The waste heat power generation system includes a condensate pump, and the water vapor outlet of the condensate pump is connected to the residue cooler through a first electric valve, the water vapor outlet of the residue cooler is connected to the deaerator through a second electric valve, and a third electric valve is arranged between the condensate pump and the deaerator.

[0015] The method for waste treatment using the above system comprises the following steps:

[0016] (S1) The waste sent out from the pretreatment workshop is sent into the multi-phase waste pre-combustion furnace through three waste inlets, and the air volume regulating valve on the branch pipe of the tertiary air duct and the exhaust gas branch pipe is used to adjust the air volume ratio on the branch pipe and the exhaust gas branch pipe and control the injection amount of the burner to control the operating temperature of the high-temperature pre-treatment system;

[0017] (S2) the residue after being treated by the high temperature pretreatment system is sent to a decomposition furnace for treatment through a material separation device or sent to a residue cooling and conveying system;

[0018] (S3) the residue sent to the residue cooling and conveying system is cooled by heat exchange with circulating water sent by a circulating water pump and then sent to a residue bin;

[0019] (S4) The condensate pumped out by the waste heat power generation system exchanges heat with the circulating water sent out in (S3) through a water-to-water heat exchanger and is heated up before entering the deaerator; or by closing the third electric valve and opening the first electric valve and the second electric valve, the circulating water sent out by the circulating water pump exchanges heat with the residue sent into the residue cooling and conveying system and is heated up before entering the deaerator, and the residue is cooled and sent to the residue bin.

[0020] Beneficial effects: (1) The present invention adopts a high-temperature pre-treatment system to pre-treat organic waste, which is suitable for various real situations such as a wide variety of organic wastes, complex sources, large fluctuations in composition, and large differences in physical and chemical composition, and does not affect the stable operation of the cement clinker burning system; (2) The present invention uses tertiary air and waste gas from the waste pre-treatment workshop and temporary storage workshop as combustion air, which can not only reduce the auxiliary fuel consumption of the high-temperature pre-treatment system and save waste gas treatment, but also control the amount of combustion air entering the high-temperature pre-treatment system by adjusting the air volume and ratio of the tertiary air and the waste gas. and temperature, and at the same time coordinates with the burner combustion volume regulation to control the temperature in the high-temperature pre-treatment system and maintain it within a certain temperature range, thereby minimizing the negative impact of the unstable calorific value of organic waste on the cement kiln clinker burning system; (3) The outlet of the high-temperature pre-treatment system of the present invention is connected to a material distribution device, which can deliver the pre-treated residue to the decomposition furnace or to the residue cooling and conveying system. The residue can be cooled and conveyed to the raw material batching system through the cooling and conveying system, which can greatly increase the amount of organic waste that is co-treated without affecting the stable operation of the cement clinker burning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a system for improving the proportion of organic waste co-disposal in cement kilns according to the present invention;

[0022] Figure 2 Another embodiment of the waste heat power generation system of the present invention;

[0023] Figure 3 The material and heat balance calculation results of the high-temperature pre-treatment system for treating 250t / d of organic waste according to the present invention are shown. DETAILED DESCRIPTION

[0024] Example 1: Figure 1As shown, the system for improving the proportion of organic waste co-treatment in cement kilns of the present invention comprises a decomposition furnace 100, a tertiary air duct 101 connected to the decomposition furnace 100, a high temperature pre-treatment system 200, a residue cooling and conveying system 300, a waste heat power generation system 400 and a waste pretreatment system 500. The high temperature pre-treatment system 200 comprises a sealed feeding device 1, a waste liquid spray gun 2, a burner 3 and a multi-phase waste pre-combustion furnace 4, the waste outlet of the multi-phase waste pre-combustion furnace 4 is connected to a material distribution device 5, and the outlet of the material distribution device 5 is respectively connected to the decomposition furnace 100 through a first valve 6 and to the residue cooling and conveying system 300 through a second valve 7. The residue cooling and conveying system 300 comprises a residue cooler 8, a slag bin 9, a gate valve 10 and a conveyor 11. The waste heat power generation system 400 comprises a circulating water pump 12, a water-to-water heat exchanger 13, a deaerator 401 and a condensate pump 402. The waste pretreatment system 500 includes a fan 15 , a second air volume regulating valve 16 and a third air volume regulating valve 17 .

[0025] The front end of the multiphase waste precombustion furnace 4 in the high temperature pretreatment system 200 of the present invention is provided with three types of waste inlets (solid, semi-solid, and low calorific value liquid). Specifically, the front end of the multiphase waste precombustion furnace 4 is respectively connected to the waste outlet from the pretreatment workshop (temporary storage workshop), including a first inlet for solid waste, a second inlet for semi-solid waste, and a third inlet for low calorific value liquid waste. The solid waste pre-treated in the pretreatment workshop (temporary storage workshop) enters the multiphase waste precombustion furnace 4 through the sealed feeding device 1. The sealed feeding device 1 can ensure the sealing and safety of the furnace body during the feeding process. In this embodiment, the sealed feeding device 1 can be a spiral reamer conveying device or a pushing device with a double-layer sealing valve; the semi-solid waste after pretreatment directly enters the multiphase waste precombustion furnace 4, and the low calorific value liquid waste enters the multiphase waste precombustion furnace 4 through the waste liquid spray gun 2. The front end of the multiphase waste precombustion furnace 4 is also provided with an inlet connected to the burner 3. The burner 3 can use oil and natural gas as fuel, or use high calorific value liquid waste sent from the pretreatment workshop (temporary storage workshop) as fuel.

[0026] The combustion air inlet of the multiphase waste precombustion furnace 4 is respectively connected to the waste gas branch pipe 502 of the pretreatment workshop (temporary storage workshop) of the waste pretreatment system 500 and the branch pipe 102 of the tertiary air duct 101, and the first air volume regulating valve 14 is arranged on the branch pipe 102 of the tertiary air duct 101. The air at the combustion air inlet is partly from the branch pipe 102 of the tertiary air duct, and partly from the pretreatment workshop 501. The outlet of the fan 15 is respectively provided with two branch pipes, and the waste gas is respectively sent to the multiphase waste precombustion furnace 4 and the emergency deodorization system 503 for disposal through the two branch pipes. The two branch pipes are respectively provided with a second air volume regulating valve 16 and a third air volume regulating valve 17 to adjust the air volume of the two branch pipes. The present invention controls the amount and temperature of the combustion air entering the multiphase waste precombustion furnace 4 by adjusting the first air volume regulating valve 14 on the branch pipe 102 and the second air volume regulating valve 16 and the third air volume regulating valve 17 arranged at the outlet of the fan 15.

[0027] In this embodiment, the main body of the multiphase waste precombustion furnace 4 adopts a rotary kiln structure with a variable speed, which is inclined at an angle of 2° to 5° to the horizontal plane. The residence time and combustion state of the waste in the multiphase waste precombustion furnace 4 are controlled by adjusting the speed of the rotary kiln, the spraying amount of the burner 3, and the air intake volume and air intake temperature of the combustion air to ensure the disposal effect.

[0028] The rear end of the multiphase waste precombustion furnace 4 is a residue outlet, which is connected to a material distributor 5. The material distributor 5 has two channels, each of which is provided with a first valve 6 and a second valve 7. One of the two channels of the material distributor 5 is connected to the decomposition furnace 100, and the other is connected to the residue inlet of the residue cooler 8. The destination of the residue of the material distributor 5 is determined according to the amount and composition of the residue generated after the organic waste is treated by the multiphase waste precombustion furnace 4, and the influence on the stable operation of the cement clinker burning system: when the residue directly enters the decomposition furnace 100 and the influence on the stable operation of the cement clinker burning system is acceptable, the material distributor 5 sends the residue to the decomposition furnace 100; otherwise, the material distributor 5 sends the residue to the residue cooler 8.

[0029] In this embodiment, the residue cooler 8 of the residue cooling and conveying system 300 adopts a water-cooled drum slag cooler, and its circulating cooling water pipeline is connected to the water-to-water heat exchanger 13 provided in the waste heat power generation system 400 of the cement production line. The residue outlet of the residue cooler 8 is connected to the slag bin 9, and the slag bin 9 is provided with a gate valve 10 and connected to the conveyor 11, and the conveyor 11 is connected to the raw material batching system.

[0030] The waste heat power generation system 400 for residue heat recovery in the present invention is a conventional waste heat power generation system in a new dry cement kiln system with an additional water-to-water heat exchanger 13. In addition to the steam turbine, waste heat boiler, generator, etc. (not shown in the figure) used in the prior art, it also includes a deaerator and a condensate pump. The condensate from the condenser is heated by the water-to-water heat exchanger 13 and then sent to the deaerator 401. The waste heat power generation system 400 is also provided with a condensate pump 402.

[0031] As an optional embodiment, the water-to-water heat exchanger 13 of the waste heat power generation system 400 can be arranged at the water outlet of the deaerator 401. As another optional embodiment of the present invention, Figure 2 As shown, the water-to-water heat exchanger 13 of the waste heat power generation system 400 of the present invention can be removed, and the condensed water at the outlet of the condenser can directly enter the cooling water pipeline of the residue cooler, and after absorbing the heat of the residue, enter the deaerator 401. The pipeline is provided with a first electric valve 81, a second electric valve 82 and a third electric valve 83, which are used to control the flow direction of water in the pipeline. The recovery process of the residue waste heat using this embodiment is: close the third electric valve 83, open the first electric valve 81 and the second electric valve 82, and the condensed water at the outlet of the condenser directly enters the residue cooler 8 for heat exchange, and after absorbing the heat of the residue, enters the deaerator 401.

[0032] Example 2: The system for increasing the proportion of organic waste co-treatment in cement kilns as described in Example 1 is used to treat residues, thereby recovering the waste heat of the residues and increasing the power generation of the system.

[0033] (1) Heat balance calculation of high temperature pretreatment system for organic waste treatment

[0034] The calculation uses the tertiary air of the cement production line as part of the combustion air source and heat source, and adjusts the tertiary air supply ratio to ensure that the rotary kiln does not need supplementary combustion. Organic waste with low calorific value (1000kcal / kg) is selected as the research object, and its composition is shown in Table 1.

[0035] Table 1 Elemental composition of low calorific value (1000 kcal / kg) organic waste materials co-processed in cement kilns

[0036] type C H O N S Cl Water ASH F Composition ratio Hazardous waste 10.00％ 2.20％ 4.30％ 0.00％ 0.00％ 0.00％ 40.00％ 43.50％ 0.00％ 100％

[0037] The design parameters are selected as follows:

[0038] ①The outlet flue gas temperature is 1000℃.

[0039] ②The excess air coefficient is 1.17 and the air leakage ratio is 10%.

[0040] ③ The multiphase waste pre-combustion furnace is a rotary kiln with an outer diameter of 4.0m, a length of 15m, and an insulation layer thickness of 300mm.

[0041] ④The ambient temperature is 20℃ and the local atmospheric pressure is 101.325kpa.

[0042] ⑤The tertiary air comes from the 5000t / d clinker production line, and the temperature is 900℃.

[0043] The scale of organic waste disposal in a single cement line is 75,000 tons / year (250t / d). The simulation results are as follows: Figure 3 shown.

[0044] (2) Exit flue gas composition

[0045] Table 2 Composition of flue gas at the outlet of high temperature pretreatment system for co-treatment of 250t / d organic waste

[0046] Element <![CDATA[O 2 ]]> <![CDATA[CO 2 ]]> <![CDATA[N 2 ]]> HkDJ <![CDATA[H 2 O(Steam)]]> total <![CDATA[Concentration Nm 3 / h]]> 1871 1254 14109 829 6840 24904 Volume fraction 7.5％ 5.0％ 56.7％ 3.3％ 27.5％ 100％

[0047] (3) Others

[0048] ①The flue gas inlet velocity is 0.14m / s and the outlet velocity is 3.60m / s.

[0049] ② Based on the material and heat balance calculation results, the combustion rate of organic matter in organic waste is 64.48%.

[0050] ③The proportion of tertiary wind is 13%.

[0051] When the organic waste does not enter the decomposition furnace but enters the residue cooling and conveying system 300, the waste heat recovery of the system is: the capacity of the cement clinker line corresponding to this example is 5000t / d, the coordinated disposal of organic waste is 250t / d, the ash content is 43.5%, the residue temperature is 1000℃, the temperature after cooling is 130℃, and the waste heat of the recoverable residue (all the residue enters the residue cooling and conveying system) is converted into standard coal of 3.38t / d, which can increase the condensate temperature (28t / h) of the waste heat power generation system 400 from 40℃ to 74.4℃. According to the thermal efficiency of 20%, the annual power generation is increased by about 5.81×10 6 kWh.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for increasing the proportion of organic waste co-processing in cement kilns, characterized in that: The invention comprises a decomposition furnace (100), a tertiary air duct (101) connected to the decomposition furnace (100), a high-temperature pre-treatment system (200), a residue cooling and conveying system (300), a waste heat power generation system (400) connected to the residue cooling and conveying system (300), and a waste pre-treatment system (500); the waste outlet of the waste pre-treatment system (500) is connected to the waste inlet of the high-temperature pre-treatment system (200), and the combustion air inlet of the high-temperature pre-treatment system (200) is simultaneously connected to the waste gas outlet of the waste pre-treatment system (500) and the tertiary air duct (101). The branch pipe (102) is connected, the flue gas outlet of the high-temperature pre-treatment system (200) is connected to the decomposition furnace (100), the residue outlet of the high-temperature pre-treatment system (200) is connected to the inlet of the material distribution device (5), and the outlet of the material distribution device (5) is simultaneously connected to the decomposition furnace (100) and the residue cooling and conveying system (300); the outlet of the material distribution device (5) is respectively provided with a first passage connected to the residue cooling and conveying system (300) and a second passage connected to the decomposition furnace (100), the first passage is provided with a first valve (6), and the second passage is provided with a second valve (7).

2. The system for increasing the proportion of organic waste co-processing in cement kilns according to claim 1 is characterized in that: The branch pipe (102) delivers the tertiary air into the combustion air inlet of the high-temperature pre-treatment system (200), and a first air volume regulating valve (14) is provided on the pipeline of the branch pipe (102).

3. The system for increasing the proportion of organic waste co-processed by cement kilns according to claim 2 is characterized in that: The high-temperature pre-treatment system (200) comprises a sealed feeding device (1), a waste liquid spray gun (2), a burner (3) and a multi-phase waste pre-combustion furnace (4); the inlet of the multi-phase waste pre-combustion furnace (4) is respectively provided with a first inlet for feeding solid waste, a second inlet for feeding semi-solid waste, a third inlet for feeding low calorific value liquid waste and a fourth inlet for feeding high calorific value liquid waste and ignition and combustion-aiding, the first inlet is provided with a sealed feeding device (1) for feeding solid waste, the third inlet is provided with a waste liquid spray gun (2), and the fourth inlet is provided with a burner (3); the outlet of the multi-phase waste pre-combustion furnace (4) is connected to the inlet of the material distribution device (5).

4. The system for increasing the proportion of organic waste co-processing in cement kilns according to claim 3 is characterized in that: The waste pretreatment system (500) comprises a pretreatment workshop (501), the waste outlet of the pretreatment workshop (501) is connected to the inlet of the multi-phase waste precombustion furnace (4), the waste gas outlet of the pretreatment workshop (501) is provided with a fan (15), and the outlet of the fan (15) is respectively connected to the combustion air inlet of the multi-phase waste precombustion furnace (4) and the emergency deodorization system (503).

5. The system for increasing the proportion of organic waste co-processed by cement kilns according to claim 4 is characterized in that: The outlet of the fan (15) is connected to the combustion air inlet of the multi-phase waste pre-combustion furnace (4) through the waste gas branch pipe (502), a second air volume regulating valve (16) is provided on the waste gas branch pipe (502), and a third air volume regulating valve (17) is provided between the fan (15) and the emergency deodorization system (503).

6. The system for increasing the proportion of organic waste co-processed by cement kilns according to claim 4, characterized in that: The residue cooling and conveying system (300) comprises a residue cooler (8), a residue bin (9), a gate valve (10), and a conveyor (11).

7. The system for increasing the proportion of organic waste co-processed by cement kilns according to claim 6, characterized in that: The waste heat power generation system (400) comprises a circulating water pump (12) connected to a cooling pipeline of the residue cooler (8), a water-to-water heat exchanger (13), a deaerator (401), and a condensate pump (402).

8. The system for increasing the proportion of organic waste co-processed by cement kilns according to claim 6, characterized in that: The waste heat power generation system (400) comprises a condensate pump (402), a water vapor outlet of the condensate pump (402) being connected to the residue cooler (8) via a first electric valve (81), a water vapor outlet of the residue cooler (8) being connected to the deaerator (401) via a second electric valve (82), and a third electric valve (83) being provided between the condensate pump (402) and the deaerator (401).

9. The method for waste treatment according to claim 8, characterized in that: The following steps are involved: (S1) The waste sent out from the pretreatment workshop (501) is sent into the multi-phase waste pre-combustion furnace (4) through three waste inlets, and the air volume regulating valve on the branch pipe (102) of the tertiary air duct (101) and the exhaust gas branch pipe (502) is used to adjust the air volume to be sent into the multi-phase waste pre-combustion furnace (4), and the operating temperature of the high-temperature pre-treatment system is controlled by adjusting the air volume ratio on the branch pipe (102) and the exhaust gas branch pipe (502) and controlling the injection amount of the burner (3); (S2) The residue treated by the high temperature pretreatment system (4) is sent to the decomposition furnace (100) for treatment through the material separation device (5) or sent to the residue cooling and conveying system (300); (S3) the residue sent to the residue cooling and conveying system (300) is cooled by heat exchange with circulating water sent by a circulating water pump (12) and then sent to a residue bin (9); (S4) The condensate delivered by the condensate pump (402) of the waste heat power generation system (400) is heated by heat exchange with the circulating water delivered in (S3) through the water-to-water heat exchanger (13) and then enters the deaerator (401); or by closing the third electric valve (83) and opening the first electric valve (81) and the second electric valve (82), the circulating water delivered by the circulating water pump (12) and the residue delivered to the residue cooling and conveying system (300) are heated by heat exchange and then enter the deaerator (401), and the residue is cooled and then sent to the slag bin (9).

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