A sewage sludge waste gas combined treatment cogeneration system

Abstract

The application discloses a sewage sludge waste gas combined treatment and co-production electric heating system, which comprises a sewage treatment system, a biogas power generation system, a sludge incineration power generation system, a waste heat utilization system, an energy recovery system and a waste gas treatment system; the sewage treatment system comprises an anaerobic tower; the biogas power generation system comprises a biogas generator; the sludge incineration power generation system comprises a sludge incinerator and a steam generator; the waste heat utilization system comprises a waste heat boiler, a sludge drying machine and an air preheater; the energy recovery system comprises a heat pump; and the waste gas treatment system comprises a water film dust collector. The sewage treatment generates biogas for power generation; the flue gas is used for recycling waste heat and drying sludge; the steam generated by sludge incineration is used for power generation; the flue gas is used for recycling waste heat; the collected waste gas is mixed with air to increase the temperature and is combusted with sludge; the flue gas is sequentially sent to the sludge drying machine, the air preheater and the heat pump to recover heat, and is sent to the waste gas treatment system to be discharged up to the standard. The application can effectively combine the treatment of sewage, sludge and waste gas and fully recover energy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy saving and environmental protection, and particularly relates to a combined treatment and co-production of electric heat system for sewage, sludge and waste gas. BACKGROUND

[0002] It has become a social consensus to properly and effectively treat the "three wastes" of sewage, sludge and waste gas, but there are still many problems in practical application: the advantages of anaerobic treatment of wastewater are not fully understood, the utilization rate of biogas produced by anaerobic bacteria is not high, the cost of sludge treatment is high, sludge treatment is difficult, and the treatment of waste gas generated in the process of sewage treatment is difficult. How to efficiently and low-costly treat the "three wastes" to achieve the purpose of emission reduction and fully utilize the energy contained in the "three wastes" is a problem to be solved. SUMMARY

[0003] The present application provides a combined treatment and co-production of electric heat system for sewage, sludge and waste gas to solve the above technical problems.

[0004] In order to solve the above technical problems, the present application adopts the following technical scheme:

[0005] A combined treatment and co-production of electric heat system for sewage, sludge and waste gas, comprising a sewage treatment system, a biogas power generation system, a sludge incineration power generation system, a waste heat utilization system, an energy recovery system and a waste gas treatment system. The sewage treatment system comprises an anaerobic tower, and sewage is treated by the anaerobic tower to produce biogas. The biogas power generation system comprises a biogas generator, and the biogas produced by the anaerobic tower is sent to the biogas generator through a pipeline for combustion and power generation. The sludge incineration power generation system comprises a sludge incinerator and a steam generator, the sludge incinerator is used for sludge incineration, and the combustion steam is sent to the steam generator through a pipeline for power generation. The waste heat utilization system comprises a waste heat boiler, a sludge dryer and an air preheater, the flue gas produced by the biogas generator and the sludge incinerator is sent to the waste heat boiler through a pipeline, then to the sludge dryer through a pipeline for drying sludge, and finally to the air preheater through a pipeline. The energy recovery system comprises a heat pump, the flue gas out of the air preheater is sent to the heat pump through a pipeline to recover heat, and the heat is transported to the waste heat boiler. The waste gas treatment system comprises a water film dust collector, and the flue gas out of the heat pump is sent to the water film dust collector for dust removal.

[0006] Further, the sewage and sludge in the anaerobic tower are fully mixed to produce biogas under the action of acid-producing bacteria and methanogenic bacteria. The weight proportion of the mixed sludge is 20-30%, and the weight proportion of the acid-producing bacteria and methanogenic bacteria is 5-10%.

[0007] Further, the sewage treatment system further comprises a pressure stabilizing tank, the biogas produced by the anaerobic tower is sent to the pressure stabilizing tank through a pipeline for pressure stabilizing treatment, and the pressure stabilized biogas is sent to the biogas generator through a pipeline.

[0008] Further, the sewage treatment system further comprises a biogas purification device, the purification device comprises a desulfurization device, a decarbonization device and a dewatering device; the pressure stabilized biogas enters the desulfurization device and the decarbonization device through a pipeline, is dewatered through the dewatering device, and is sent into the biogas generator through a pipeline.

[0009] Further, the pressure stabilizing cabinet is provided with a gas supply branch pipe connected with the sludge incinerator to ignite or increase the hearth temperature when the hearth temperature is lower than 850 DEG C.

[0010] Further, the sludge in the sludge hopper has a moisture content of 50-80%.

[0011] Further, the sludge dried by the sludge dryer has a moisture content of 15-40%.

[0012] Further, the water used by the water film dust collector is treated sewage, and the drainage is subjected to aerobic treatment.

[0013] Further, the system further comprises a gas collecting pipe for collecting waste gas; one end of the gas collecting pipe is arranged in a region generating odor in the sewage treatment system, and the other end is connected with an air preheater.

[0014] Further, the air preheater is provided with an air inlet; the odor and air entering the air preheater are preheated, enter the heat pump for temperature increasing treatment through a pipeline, and are sent into the sludge incinerator through a pipeline.

[0015] The present application has the following beneficial effects:

[0016] 1. The present application uses an anaerobic tower to treat sewage to generate biogas, and then performs aerobic treatment, so that the sewage treatment process is anaerobic treatment first and then aerobic treatment, not only valuable biogas resources are obtained, but also the power consumption of the later aerobic treatment is greatly saved.

[0017] 2. The tail gas generated by biogas combustion and power generation is subjected to waste heat recovery through a waste heat boiler, realizing high-value utilization and cascade utilization of energy.

[0018] 3. The sludge generated by sewage treatment is dried by a sludge dryer on site, and then is incinerated by a sludge incinerator, and the generated steam is used for power generation, not only reducing the transportation cost of sludge treatment, but also reducing the risk of secondary pollution.

[0019] 4. The tail gas waste heat generated by sludge incineration is recovered through a waste heat boiler, and then is used for drying sludge in a sludge dryer, and is used for preheating air in an air preheater, realizing cascade utilization of heat energy.

[0020] 5. The exhaust gas is finally processed by a heat pump system to fully recover the sensible and latent heat. The waste heat is then recovered by a waste heat boiler, achieving the cascade utilization and full utilization of energy. The exhaust gas is treated by a water film dust collector and then discharged in compliance with standards. The wastewater generated is returned to the wastewater treatment system for further aerobic treatment.

[0021] This application effectively treats the "three wastes" (waste gas, wastewater, and solid waste), solves the problem of sludge treatment, and fully recovers the energy contained in the "three wastes" through a tiered recycling method. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the present invention. Detailed Implementation

[0024] To facilitate a better understanding of the present invention, the following examples are provided in conjunction with the accompanying drawings. These examples fall within the scope of protection of the present invention, but do not limit the scope of protection of the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, a combined wastewater, sludge, and waste gas treatment and cogeneration system includes a wastewater treatment system, a biogas power generation system, a sludge incineration power generation system, a waste heat utilization system, an energy recovery system, and a waste gas treatment system. The wastewater treatment system includes an anaerobic digester, through which wastewater is treated to produce biogas. The biogas power generation system includes a biogas generator, through which the biogas produced in the anaerobic digester is piped to the biogas generator for combustion and power generation. The sludge incineration power generation system includes a sludge incinerator and a steam generator. The steam generator is a back-pressure generator, and the sludge incinerator is used for sludge incineration. A waste heat boiler feedwater is connected to... The sludge incinerator converts boiler feedwater into steam during combustion, which is then piped to a steam generator to generate electricity. The waste heat utilization system includes a waste heat boiler, a sludge dryer, and an air preheater. Flue gas generated by the biogas generator and sludge incinerator enters the waste heat boiler through pipes, then enters the sludge dryer through pipes to dry the sludge, and finally enters the air preheater through pipes. The energy recovery system includes a heat pump. Flue gas exiting the air preheater enters the heat pump through pipes to recover heat and is then transported to the waste heat boiler. The exhaust gas treatment system includes a water film dust collector. Flue gas exiting the heat pump enters the water film dust collector for dust removal.

[0027] The sewage and sludge in the anaerobic tower are fully mixed, and the sewage and sludge have a high content of organic matter, which produces biogas under the action of acid-producing bacteria and methanogenic bacteria; the weight proportion of the mixed sludge is 20%, and the weight proportion of the acid-producing bacteria and the methanogenic bacteria is 5%.

[0028] The sewage treatment system further comprises a pressure stabilizing tank, the biogas produced by the anaerobic tower is sent into the pressure stabilizing tank through a pipeline, and the produced biogas is subjected to pressure stabilizing treatment; the pressure-stabilized biogas is sent into a biogas generator through a pipeline.

[0029] The sewage treatment system further comprises a biogas purification device, the purification device comprises a desulfurization device, a decarbonization device and a dewatering device; the pressure-stabilized biogas is sent into the desulfurization device and the decarbonization device through a pipeline, and is dewatered through the dewatering device, and then is sent into the biogas generator through a pipeline. After the biogas is subjected to pressure stabilizing and purification treatment, a branch pipeline is connected to a flare, and the biogas is burned and discharged through the flare when the biogas power generation system is started or stopped or when the subsequent system has insufficient demand.

[0030] The pressure stabilizing tank is connected to a sludge incinerator through a gas supply branch pipeline, and the biogas is introduced into the sludge incinerator to start ignition and use the waste heat boiler, or to increase the temperature of the sludge incinerator when the sludge is not sufficiently dried and the hearth temperature of the sludge incinerator is lower than 850℃.

[0031] The water content of the sludge in the sludge hopper is 50%.

[0032] The water content of the dried sludge in the drying machine is 15%.

[0033] The heat pump comprises a flue gas evaporator, an air heating condenser and a feed water heating condenser. The flue gas evaporator is connected to the flue gas from the air preheater, the air heating condenser is connected to the mixed gas composed of the collected exhaust gas and air from the air preheater, the mixed gas is heated and then introduced into the sludge incinerator for incineration, and the boiler feed water is introduced into the feed water heating condenser, and the boiler feed water from the feed water heating condenser is introduced into the waste heat boiler.

[0034] The water film dust collector uses the treated sewage as water, and the drainage is subjected to aerobic treatment.

[0035] The system further comprises a gas collecting pipe for collecting exhaust gas; one end of the gas collecting pipe is arranged in a region where the sewage treatment system produces odor, and the other end of the gas collecting pipe is connected to the air preheater.

[0036] The air preheater is provided with an air inlet, the odor and air entering the air preheater are preheated, and then are introduced into the heat pump through a pipeline for temperature increasing treatment, and then are introduced into the sludge incinerator through a pipeline.

[0037] Example 2

[0038] As Figure 1As shown, a sewage sludge waste gas combined treatment cogeneration system, comprising a sewage treatment system, a biogas power generation system, a sludge incineration power generation system, a waste heat utilization system, an energy recovery system, and a waste gas treatment system; the sewage treatment system comprises an anaerobic tower, and sewage is treated in the anaerobic tower to produce biogas; the biogas power generation system comprises a biogas generator, and the biogas produced by the anaerobic tower is sent into the biogas generator through a pipeline for combustion and power generation; the sludge incineration power generation system comprises a sludge incinerator and a steam generator, the steam generator is a back pressure generator, the sludge incinerator is used for incineration of sludge, and boiler feed water is supplied into the sludge incinerator, which is changed into steam during combustion and sent into the steam generator through a pipeline for power generation; the waste heat utilization system comprises a waste heat boiler, a sludge dryer, and an air preheater, flue gas produced by the biogas generator and the sludge incinerator is sent into the waste heat boiler through a pipeline, then into the sludge dryer through a pipeline for drying of sludge, and finally into the air preheater through a pipeline; the energy recovery system comprises a heat pump, flue gas from the air preheater is sent into the heat pump through a pipeline for heat recovery and then delivered to the waste heat boiler; and the waste gas treatment system comprises a water film dust collector, flue gas from the heat pump is sent into the water film dust collector for dust removal.

[0039] The sewage and sludge in the anaerobic tower are fully mixed, and there is a high content of organic matter in the sewage and sludge, which produces biogas under the action of acid-producing bacteria and methanogenic bacteria; the weight proportion of the mixed sludge is 25%, and the weight proportion of the acid-producing bacteria and the methanogenic bacteria is 8%.

[0040] The sewage treatment system further comprises a pressure stabilizing tank, the biogas produced by the anaerobic tower is sent into the pressure stabilizing tank through a pipeline for pressure stabilizing treatment, and the pressure stabilized biogas is sent into the biogas generator through a pipeline.

[0041] The sewage treatment system further comprises a biogas purification device, the purification device comprises a desulfurization device, a decarbonization device, and a dewatering device; the pressure stabilized biogas is sent into the desulfurization device and the decarbonization device through a pipeline for treatment, and after dewatering by the dewatering device, the biogas is sent into the biogas generator through a pipeline. After the biogas is treated by pressure stabilization and purification, a branch pipeline is branched out to connect a flare, and when the biogas power generation system is started or stopped or when the subsequent system has insufficient demand, the biogas is burned and discharged through the flare.

[0042] The pressure stabilizing tank is provided with a gas supply branch pipe connected to the sludge incinerator, and the biogas is supplied into the sludge incinerator for starting and ignition of the incinerator, use of the waste heat boiler, or increasing the temperature of the incinerator when the sludge is not sufficiently dried and the temperature of the hearth of the incinerator is lower than 850℃.

[0043] The moisture content of the sludge in the sludge hopper is 70%.

[0044] The moisture content of the dried sludge in the dryer is 30%.

[0045] The heat pump comprises a flue gas evaporator, an air heating condenser, and a feed water heating condenser. The flue gas evaporator is connected to flue gas from the air preheater, the air heating condenser is connected to mixed gas composed of collected exhaust gas and air from the air preheater, the mixed gas is heated and then enters the sludge incinerator for incineration, and the boiler feed water enters the feed water heating condenser, and the boiler feed water from the feed water heating condenser enters the waste heat boiler.

[0046] The water film dust collector uses treated sewage as water, and the drainage is subjected to aerobic treatment.

[0047] The system further comprises a gas collecting pipe for collecting exhaust gas, one end of the gas collecting pipe is arranged in an area where the sewage treatment system produces odor, and the other end is connected to the air preheater.

[0048] The air preheater is provided with an air inlet, the odor entering the air preheater is heated and then enters the heat pump through a pipeline for temperature rising treatment, and then is sent into the sludge incinerator through a pipeline.

[0049] Example 3

[0050] As shown in Figure 1 A sewage and sludge exhaust gas combined treatment and co-production of electric heating system comprises a sewage treatment system, a biogas power generation system, a sludge incineration power generation system, a waste heat utilization system, an energy recovery system, and an exhaust gas treatment system. The sewage treatment system comprises an anaerobic tower, and sewage is treated in the anaerobic tower to produce biogas. The biogas power generation system comprises a biogas generator, and the biogas produced by the anaerobic tower is sent into the biogas generator through a pipeline for combustion and power generation. The sludge incineration power generation system comprises a sludge incinerator and a steam generator, the steam generator is a back pressure generator, the sludge incinerator is used for incineration of sludge, the waste heat boiler feed water is connected to the sludge incinerator, and the boiler feed water is changed into steam during combustion and sent into the steam generator through a pipeline for power generation. The waste heat utilization system comprises a waste heat boiler, a sludge dryer, and an air preheater, the flue gas produced by the biogas generator and the sludge incinerator is sent into the waste heat boiler through a pipeline, then into the sludge dryer through a pipeline for drying of sludge, and finally into the air preheater through a pipeline. The energy recovery system comprises a heat pump, the flue gas from the air preheater is sent into the heat pump through a pipeline for heat recovery and then sent to the waste heat boiler. The exhaust gas treatment system comprises a water film dust collector, and the flue gas from the heat pump is sent into the water film dust collector for dust removal.

[0051] The sewage and sludge in the anaerobic tower are fully mixed, and there is a high content of organic matter in the sewage and sludge, which produces biogas under the action of acid-producing bacteria and methanogenic bacteria. The weight proportion of the mixed sludge is 30%, and the weight proportion of the acid-producing bacteria and methanogenic bacteria is 10%.

[0052] The sewage treatment system further comprises a pressure stabilizing tank, the biogas produced by the anaerobic tower is sent into the pressure stabilizing tank through a pipeline for pressure stabilizing treatment, and the pressure stabilized biogas is sent into the biogas generator through a pipeline.

[0053] The sewage treatment system further comprises a biogas purification device, the purification device comprising a desulfurization device, a decarbonization device and a dewatering device; the pressure-stabilized biogas enters the desulfurization device and the decarbonization device through a pipeline for treatment, and after dewatering by the dewatering device, the biogas is sent into a biogas generator through a pipeline. After the pressure-stabilized and purified biogas, a branch pipe is connected to a flare, and when the biogas power generation system is started or stopped or the subsequent system is insufficient, the biogas is burned and discharged through the flare.

[0054] The pressure-stabilizing tank is provided with a gas supply branch pipe connected to the sludge incinerator, and the biogas is introduced into the sludge incinerator for starting and ignition, waste heat boiler use, or when the sludge drying is insufficient and the hearth temperature of the incinerator is lower than 850 DEG C, the temperature of the incinerator is increased.

[0055] The moisture content of the sludge in the sludge hopper is 80%.

[0056] The moisture content of the dried sludge in the drying machine is 40%.

[0057] The heat pump comprises a flue gas evaporator, an air heating condenser and a feed water heating condenser. The flue gas evaporator is connected to the flue gas from the air preheater, the air heating condenser is connected to the mixed gas composed of the collected exhaust gas and air from the air preheater, and the mixed gas is heated and enters the sludge incinerator for incineration; and the boiler feed water enters the feed water heating condenser, and the boiler feed water from the feed water heating condenser enters the waste heat boiler.

[0058] The water film dust collector uses the treated sewage as water, and the drainage is subjected to aerobic treatment.

[0059] The system further comprises a gas collecting pipe for collecting exhaust gas; one end of the gas collecting pipe is arranged in the area where the sewage treatment system generates odor, and the other end is connected to the air preheater.

[0060] The air preheater is provided with an air inlet, the odor and air entering the air preheater are heated and enter the heat pump through a pipeline for temperature increase treatment, and then enter the sludge incinerator through a pipeline for treatment.

[0061] In the present application, the specific types of the anaerobic tower, the pressure-stabilizing tank, the biogas generator, the desulfurization device, the decarbonization device, the dewatering device, the waste heat boiler, the sludge drying machine, the air preheater, the heat pump, the water film dust collector, the steam generator and the sludge incinerator are not the improvement points of the present application, and are not described herein.

[0062] The use method is as follows: the organic wastewater enters the anaerobic tower, under the action of acid-producing bacteria and methanogens, the COD in the wastewater is converted into biogas, after the pressure stabilization in the pressure stabilization cabinet, the purification treatment in the desulfurization device, the decarbonization device and the dehydration device, the biogas enters the biogas generator to burn and generate electricity. The flue gas generated by the biogas combustion enters the waste heat boiler to recover waste heat, and then enters the sludge drying machine to dry the sludge. The dried sludge enters the sludge incinerator to be incinerated; the superheated steam generated by the incineration generates electricity through the steam generator, and the output saturated steam can be used for production, and the incineration discharged ash can be landfilled; the generated flue gas enters the waste heat boiler to recover waste heat, and the incineration discharged ash can be landfilled.

[0063] The flue gas generated by the biogas combustion and the sludge incineration enters the waste heat boiler to heat the feed water into the incinerator, and then enters the sludge drying machine to dry the sludge; the flue gas from the sludge drying machine enters the air preheater to heat the air into the incinerator, and the collected waste gas collected by the gas collecting pipe; the flue gas from the air waste heat exchanger continues to enter the heat pump to continue to recover heat: part of the preheated boiler feed water, the heated boiler feed water enters the waste heat boiler again; the other part is used for reheating the collected waste gas and air preheated by the air preheater, and the heated and warmed collected waste gas and air enter the incinerator to be incinerated.

[0064] After the flue gas from the heat pump, it enters the waste gas treatment system, and is dusted by the water film dust collector; the water used by the water film dust collector is the treated wastewater, and the treated flue gas has been dusted, desulfurized and denitrified, and realizes the standard discharge, and the generated wastewater continues to return to the wastewater treatment system for treatment; the nitrogen oxides and sulfur oxides in the water are treated by the aerobic treatment, the anoxic treatment and the coagulation system of the wastewater treatment system, and are discharged after reaching the standard.

[0065] It should be noted that, in this text, relational terms such as first and second are used only to distinguish one entity or action from another, and do not necessarily require or imply that there is any such actual relationship or order between these entities or actions. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the statement "including a limited element" does not exclude the existence of other identical elements in the process, method, article or equipment including the element.

[0066] The above is only the preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A combined sewage, sludge, and waste gas treatment system with co-generation of electricity and heat, characterized in that, The sewage treatment system, the biogas power generation system, the sludge incineration power generation system, the waste heat utilization system, the energy recovery system, and the waste gas treatment system are included. The sewage treatment system includes an anaerobic tower, and sewage is treated by the anaerobic tower to produce biogas. The biogas power generation system includes a biogas generator, and the biogas produced by the anaerobic tower is sent into the biogas generator by a pipeline to produce power. The sludge incineration power generation system includes a sludge incinerator and a steam generator, the sludge incinerator is used for sludge incineration, and the combustion steam is sent into the steam generator by a pipeline to produce power. The waste heat utilization system includes a waste heat boiler, a sludge dryer, and an air preheater, the flue gas produced by the biogas generator and the sludge incinerator is sent into the waste heat boiler by a pipeline, then into the sludge dryer by a pipeline to dry the sludge, and finally into the air preheater by a pipeline. The energy recovery system includes a heat pump, the flue gas out of the air preheater is sent into the heat pump by a pipeline to recover heat, and is transported to the waste heat boiler. The waste gas treatment system includes a water film dust collector, and the flue gas out of the heat pump is sent into the water film dust collector for dust removal. A gas collecting pipe is further included for collecting waste gas, one end of the gas collecting pipe is arranged in a region where the sewage treatment system produces odor, and the other end is connected with the air preheater. The air preheater is provided with an air inlet, the odor and air entering the air preheater are preheated, then are sent into the heat pump by a pipeline for temperature rising treatment, and are finally sent into the sludge incinerator by a pipeline for treatment.

2. The combined system for treating sewage sludge and waste gas according to claim 1, characterized in that, The sewage and sludge in the anaerobic tower are fully mixed, and biogas is produced under the action of acid-producing bacteria and methanogenic bacteria.

3. The combined system for treating sewage sludge and waste gas according to claim 2, characterized in that, The sewage treatment system further includes a pressure stabilizing cabinet, the biogas produced by the anaerobic tower is sent into the pressure stabilizing cabinet by a pipeline for pressure stabilizing treatment, and the pressure stabilized biogas is sent into the biogas generator by a pipeline.

4. The combined system for treating sewage sludge and waste gas according to claim 3, characterized in that, The sewage treatment system further includes a biogas purification device, the biogas purification device includes a desulfurization device, a decarbonization device, and a dehydration device, the pressure stabilized biogas is sent into the desulfurization device and the decarbonization device by a pipeline for treatment, and is sent into the biogas generator by a pipeline after dehydration by the dehydration device.

5. The combined system for treating sewage sludge and waste gas according to claim 4, characterized in that, The pressure stabilizing cabinet is provided with a gas sending branch pipe connected with the sludge incinerator for ignition or combustion support when the hearth temperature is lower than 850℃.

6. The combined system for treating sewage sludge and waste gas according to claim 5, characterized in that, The sludge dried by the sludge dryer has a water content of 15-40%.

7. The combined system for treating sewage sludge and waste gas according to claim 1, characterized in that, The water film dust collector uses treated sewage as water, and the drainage is subjected to aerobic treatment.

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