CN114383138A

CN114383138A - Kitchen waste and household waste combined incineration treatment process

Info

Publication number: CN114383138A
Application number: CN202111643988.XA
Authority: CN
Inventors: 徐学骁; 刘杰; 刘军; 朱菁; 刘�东; 王瑾瑾
Original assignee: Nanjing Wondux Environmental Protection Technology Co ltd
Current assignee: Nanjing Wondux Environmental Protection Technology Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-04-22

Abstract

The invention discloses a kitchen waste and household waste combined incineration treatment process. The kitchen waste treatment station and the household waste incineration station are built on the same site in the process; the kitchen waste treatment system and the household waste incineration system share infrastructure and public and auxiliary projects; impurity and sundries separated from the kitchen waste are treated cooperatively through incineration, the produced biogas is put into a furnace to be incinerated for power generation or steam production, and the surplus heat energy generated by the incineration of the household waste is used for the treatment of the kitchen waste; malodorous gas generated in each treatment section of the kitchen waste and a household garbage bin is collected by negative pressure and is used as combustion-supporting air of an incinerator for treatment. The kitchen waste and the household waste are cooperatively treated to realize facility sharing, technical cooperation, raw material complementation and personnel linkage, so that land resources are saved, the construction cost and the operation cost of treatment facilities are effectively reduced, the profit capacity of the urban basic environment-friendly facility is integrally improved, and a new mode of cooperative treatment of urban waste is provided.

Description

Kitchen waste and household waste combined incineration treatment process

Technical Field

The invention relates to a process for treating and utilizing kitchen waste, in particular to a process for treating kitchen waste and household garbage by combustion.

Background

The kitchen waste refers to food residues, residual liquid, waste oil and other waste generated in the processes of food processing, food service and catering, and is relatively large in proportion to municipal domestic waste. The method has the characteristics of large oil content, complex composition, high organic matter content and the like, and severe environmental pollution is easily caused by improper treatment of the kitchen waste. At present, domestic kitchen waste treatment plants mostly adopt a newly-built mode, and the kitchen waste treatment plants and household waste incineration plants are independently built, so that the problems of low utilization rate of matched facilities, overlarge investment intensity, difficult site selection caused by an adjacent avoidance effect, large operation investment, poor profit level and the like exist. Therefore, realizing the cooperative treatment of the kitchen waste and the household waste is an effective means for solving the problems.

Patent CN 110976472A discloses a kitchen waste and household waste co-processing method, which comprises the following steps: (1) pretreatment: preparing raw material slurry for fermentation from kitchen waste; the household garbage is dry garbage for incineration; (2) resource utilization: preparing the raw material slurry into methane; dry garbage incineration power generation; (3) and (3) pollutant treatment: reducing biogas residues, and treating biogas slurry; purifying the flue gas; (4) utilizing the methane; and (4) methane storage. The patent draws forth the thought of the cooperative treatment of the kitchen waste and the household waste to a certain extent, but does not deeply provide a method for deeply utilizing the kitchen waste and the household waste in a cooperative manner.

Patent CN 210125627U discloses a kitchen garbage and domestic waste coprocessing facility, including preprocessing device, anaerobic fermentation device, marsh gas utilization device, odor collection device's kitchen garbage treatment facility and including burning furnace, steam generation device, gas cleaning device, leachate treatment facility's domestic waste incineration disposal facility. The patent defines a kitchen project and incineration project cooperative treatment method to a certain extent, but does not provide an effective way for utilizing the waste heat of the smoke and does not provide an effective means for extracting oil from the kitchen waste.

The patent provides a process for integrally grasping the cooperation of the incineration of the whole kitchen waste and the household garbage, and simultaneously provides a specific process operation method, and provides a new mode and a new method for the cooperative treatment of the town garbage.

Disclosure of Invention

The invention aims to solve the problems that an innovative scheme is provided aiming at the defects in the prior art, and particularly provides a kitchen waste and domestic waste co-incineration treatment process, which effectively reduces the construction cost and the operation cost of urban kitchen and domestic waste treatment facilities, integrally improves the profitability of urban basic environment-friendly facilities, and provides a new mode for urban waste co-treatment.

In order to solve the problems, the invention adopts the following scheme:

the slurry concentrator can realize the control of the water content of the slurry at the outlet by adjusting the rotating speed of the screw conveyer.

The invention has the following technical effects: firstly, the kitchen treatment facility and the household garbage treatment facility are built together, the supporting facilities are shared, the technology is cooperated, the raw materials are complemented, the personnel are linked, the land resources are saved, and the construction cost and the operation cost of the treatment facility are effectively reduced.

And secondly, solid residues screened out from the kitchen waste enter an incinerator for incineration, methane generated by kitchen treatment enters the incinerator for power generation or steam generation as fuel, and the kitchen atomization oil extraction and slurry concentration use are supplied by the waste heat of the incineration flue gas, so that the deep comprehensive utilization of solid waste resources is realized in cooperation, and the whole process resource utilization rate is high.

And thirdly, malodorous gas generated in the workshop section of the whole plant is taken as combustion-supporting air to enter the incinerator, so that the investment of waste gas treatment facilities is effectively reduced. The slurry is dried by fully utilizing the waste heat of the flue gas, and the dry anaerobic fermentation is adopted, so that the biogas slurry treatment pressure is reduced. The whole process has low difficulty in treating the three wastes and small environmental influence.

Drawings

FIG. 1 is a block diagram of the process flow of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the present invention more clear, the present invention is further described with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1, a kitchen waste and household waste incineration treatment process, the process flow comprises: the kitchen waste treatment system comprises a kitchen waste pretreatment system, a kitchen waste anaerobic digestion system, a methane system and a household waste incineration and flue gas purification system.

Further, the kitchen waste pretreatment system is composed of a large substance screening device, a magnetic separation device, a fine separation pulping device, a sand and impurity removing device, an atomization oil extraction device, a centrifugal separation device and a slurry concentrator.

Preferably, the large substance separation section adopts a low-speed rotary screening device to carry out coarse screening on the kitchen waste, the aperture of a screen mesh is 60-100mm, the screen plate, the screen holes, the screw and the rotating speed can be adjusted, and undersize materials go to the magnetic separation section. And the magnetic separation working section removes metal impurities in the kitchen waste and then removes the metal impurities to the fine pulping working section, and the metal impurities are sent out for disposal.

Preferably, the finely-divided pulping section is used for further crushing, separating and pulping the coarsely-screened kitchen waste by adopting a high-speed crushing and screening machine, the grain size of the slurry after finely-divided pulping is controlled within 8mm, TS is controlled within 8-12%, inorganic small-particle impurities which cannot be crushed are separated by a sieve plate, and the slurry is conveyed to the desanding and impurity removing section.

Preferably, a multistage partition active high-efficiency cyclone sand remover is adopted to further remove inorganic gravel impurities in the slurry, and the rotational flow velocity of the slurry is controlled to be 5-10 m.s^-1。

And further, oversize materials separated by a large-material screening, fine-separation pulping and sand and impurity removal working section are conveyed to a household garbage bin to be incinerated with household garbage in a synergic manner.

Further, the slurry after sand and impurity removal is pumped to an atomization oil extraction working section, and the flue gas at the outlet of the flue gas dust remover for burning the household garbage is introduced to the atomization oil extraction working section through a booster fan to be used as atomized airflow and also used as a slurry temperature-rising heat source.

Preferably, the slurry is atomized in a non-two-phase flow premixing mode, heat transfer is carried out simultaneously, and the ratio of atomized gas to liquid is controlled to be 50-100; the slurry is atomized into liquid drops by the flue gas in an oil atomizing and extracting section, the temperature is raised to 80-90 ℃, and the grease is recovered by centrifugal separation.

Preferably, the centrifugal separation adopts a three-phase horizontal centrifugal separator, and the centrifugal rotation speed is controlled at 2500-.

Further, after the gas phase produced in the atomized oil extraction section is condensed, the non-condensable gas is introduced by a fan and pressed to an incinerator for incineration, and condensed wastewater flows back to the front end of centrifugal separation; and (4) centrifugally separating the produced slurry with certain solid content to a slurry concentrator, and selling the grease.

Further, the slurry concentrator adopts an indirect heat exchange mode, a flue gas inlet and a flue gas outlet are arranged, the flue gas inlet is connected with an outlet of the flue gas dust remover, and the flue gas outlet is connected with an induced draft fan.

Preferably, the slurry concentrator is internally provided with a hollow propeller blade, the propeller blade is provided with a radiating fin, the slurry is pushed under the action of the propeller blade, the flue gas flows inside the propeller blade, the heat is transferred to the slurry through the radiating fin, the slurry is heated to 110 ℃, the moisture in the slurry is removed, and the slurry concentration is realized. The temperature of the flue gas inlet of the slurry concentrator is 180-200 ℃, the temperature of the flue gas outlet is 90-110 ℃, the slurry feeding temperature is 80-90 ℃, and the flow ratio of the flue gas slurry is 8-15Nm³Flue gas per kg of slurry.

Furthermore, after the generated vapor is condensed by a condenser, the non-condensable gas is introduced by a fan and pressed to an incinerator for incineration, the condensed wastewater is recycled in a fine pulping working section, and the redundant wastewater is treated by a sewage station. The slurry concentrator can realize the control of the water content of the slurry at the outlet by adjusting the rotating speed of the screw conveyor.

Furthermore, the product concentrated by the slurry concentrator is in a semisolid state and is closely conveyed to a dry anaerobic section by a screw conveyor for anaerobic digestion.

Preferably, the dry anaerobic tank can be vertical or horizontal anaerobic tank, the feeding TS is controlled at 20-50%, the operation temperature can be 35-40 deg.C or 55-60 deg.C, the retention time is 20-30 days, and mechanical stirring is provided.

Further, the slurry generates biogas under the action of anaerobic bacteria, the biogas enters a biogas cabinet for temporary storage, and enters an incinerator for power generation or steam generation after biogas purification, and the biogas purification adopts wet method/biological desulfurization, dry method desulfurization and a combination form thereof. And carrying out aerobic composting on the biogas residues generated in the dry anaerobic section, and then carrying out fertilizer utilization.

Furthermore, the household garbage incineration and flue gas purification system consists of a storage bin, a hoisting grab bucket, a pusher, an incinerator, a waste heat boiler, a semi-dry deacidification tower, an activated carbon ejector, a dust remover and an induced draft fan. The household garbage is weighed and discharged, then poured into a bin, conveyed to a hopper of a pusher through a crane grab bucket, and pushed to an incinerator under the action of the pusher. The household garbage is completely incinerated at the high temperature of above 850 ℃, the incinerated slag is conveyed by a slag discharging machine under the furnace to be discharged, and the high-temperature flue gas enters a waste heat boiler for heat exchange to generate steam for sale or further for power generation and internet surfing. And the flue gas after heat exchange enters a semi-dry deacidification tower for deacidification treatment, and the activated carbon injector injects powdered activated carbon into a pipeline between the semi-dry deacidification tower and a dust remover to be mixed with the flue gas, so that toxic and harmful substances in the flue gas are further adsorbed, and the flue gas is captured by the dust remover and then is safely buried. And finally, discharging the flue gas out of the induced draft fan.

Finally, it should be noted that the above description is only a preferred embodiment of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.

Claims

1. The kitchen waste and household waste incineration treatment process is characterized by comprising the following steps:

screening large substances, namely screening the kitchen waste incoming materials by the large substances to remove large-particle impurities with the particle size of more than 60mm, and conveying the undersize to a magnetic separation working section;

magnetic separation, namely removing metal impurities in the kitchen waste, then removing the metal impurities to a fine pulping working section, and sending the metal impurities out for disposal;

finely dividing and pulping, namely crushing organic matters into slurry with the particle size smaller than 8mm, then matching with condensed wastewater generated in a slurry concentration section to prepare slurry, wherein inorganic small particle impurities which cannot be crushed are separated through a sieve plate, and the slurry is conveyed to a sand and impurity removal section;

removing sand and impurities, and further removing inorganic gravel impurities in the slurry through a cyclone separator;

atomizing and extracting oil, pumping the slurry subjected to sand and impurity removal to an atomizing and oil extracting working section, introducing the flue gas discharged by a household garbage incineration and flue gas purification system to the atomizing and oil extracting working section through a booster fan to serve as an atomizing airflow, and simultaneously serving as a slurry heating heat source; atomizing the slurry into liquid drops by flue gas in an atomization oil extraction working section, heating to 80-90 ℃, and recovering and selling the grease through centrifugal separation; condensing gas phase produced in the atomized oil extraction section, leading non-condensable gas to an incinerator for incineration by a fan, and refluxing condensed wastewater to the front end of centrifugal separation; the slurry containing solid phase produced by centrifugal separation goes to a slurry concentrator;

concentrating the slurry, introducing the flue gas discharged by the household garbage incineration and flue gas purification system to a slurry concentrator, condensing the generated water vapor by a condenser, introducing the non-condensable gas to an incinerator for incineration by a fan, removing part of the condensed wastewater to a fine pulping working section for recycling, and treating the rest wastewater by a sewage station;

dry anaerobic digestion, namely, conveying the product concentrated by the slurry concentrator into semisolid slurry by a screw conveyor in a closed manner to a dry anaerobic section for anaerobic digestion, wherein the retention time is 20-30 days, the slurry generates methane under the action of anaerobic bacteria, the methane enters a methane cabinet for temporary storage, and the methane is purified and then enters an incinerator for power generation or steam generation; carrying out aerobic composting on biogas residues generated in the dry anaerobic section, and then carrying out fertilizer utilization;

burning the household garbage and purifying the smoke, sending the household garbage into a burning furnace, and sending the generated high-temperature smoke into a waste heat boiler for heat exchange to generate steam for sale or power generation to be networked; after the heat exchange, the flue gas is purified by the flue gas, part of the flue gas is supplied to atomization and oil extraction by the induced draft fan, part of the flue gas is supplied to concentration of slurry, and the rest of the flue gas is discharged outside.

2. The incineration treatment process of the kitchen waste and the household waste as claimed in claim 1, wherein the large-substance screening is performed by adopting a low-speed rotary screening device to perform coarse screening on the kitchen waste, the aperture of a screen mesh is 60-100mm, and a screen plate, a screen hole, a screw and the rotating speed can be adjusted; the refined pulping adopts a high-speed crushing and screening machine to further crush, separate and pulp the coarsely screened kitchen waste; the grain diameter of the slurry after the fine pulping is controlled within 8mm, and TS is controlled to be 8-12%; the sand and impurity removal adopts a multistage partition active high-efficiency cyclone sand removal technology, and the cyclone flow velocity of the slurry is controlled to be 5-10 m.s < -1 >; the atomized oil extraction adopts a high-efficiency atomized oil extraction reactor, high-temperature flue gas is sprayed in through a booster fan, the slurry is atomized in a non-two-phase flow premixing mode, heat transfer is carried out simultaneously, the ratio of atomized gas to atomized liquid is controlled to be 50-100, the centrifugal separation adopts a three-phase horizontal centrifugal separator, and the centrifugal rotation speed is controlled to be 2500-3500 rpm; the temperature of the smoke inlet of the slurry concentrator is 180-200 ℃, the temperature of the smoke outlet is 90-110 ℃, the feeding temperature of the slurry is 80-90 ℃, and the flow ratio of the smoke slurry is 8-15Nm3 smoke/kg slurry.

3. The kitchen waste and household waste incineration treatment process according to claim 1, characterized in that the dry anaerobic digestion is in the form of a vertical or horizontal anaerobic tank, the feeding TS is controlled to be 20-50%, the operation temperature is selected from the medium temperature of 35-40 ℃ or the high temperature of 55-60 ℃, the retention time is 20-30 days, and mechanical stirring is arranged in the dry anaerobic digestion tank; the biogas purification adopts wet method/biological desulfurization, dry method desulfurization and combination forms thereof.

4. The kitchen waste and household waste incineration treatment process according to claim 1, wherein the household waste incinerator is selected from a mechanical grate incinerator, a fluidized bed incinerator or a rotary incinerator, the incineration temperature is higher than 850 ℃, and the smoke retention time is longer than 2 s.

5. The kitchen waste and household waste incineration disposal process according to claim 1, wherein the household waste incineration and flue gas purification process comprises a storage bin, a crane grab, a pusher, an incinerator, a waste heat boiler, a semi-dry deacidification tower, an activated carbon injector, a dust remover and an induced draft fan; weighing and unloading the household garbage, then pouring the household garbage into a bin, conveying the household garbage to a hopper of a pusher through a travelling grab bucket, and pushing the household garbage to an incinerator under the action of the pusher; the household garbage is completely incinerated at the high temperature of above 850 ℃, the incinerated slag is conveyed by a slag discharger and discharged, and high-temperature flue gas enters a waste heat boiler for heat exchange to generate steam for sale or power generation to be networked; the flue gas after heat exchange enters a semi-dry deacidification tower for deacidification treatment, and the activated carbon injector injects powdered activated carbon into a pipeline between the semi-dry deacidification tower and a dust remover to be mixed with the flue gas, so that toxic and harmful substances in the flue gas are further adsorbed, and are captured by the dust remover and then safely buried; the flue gas is discharged by a draught fan.