A comprehensive system and method for removing odor from sludge drying and combustion in thermal power plants

Abstract

A comprehensive odor removal system and method for sludge drying and co-combustion in a thermal power plant. The system includes a sludge unloading closed bin, a sludge drying pretreatment closed workshop, an odor neutralization system, a biological inhibition system, and a ventilation system. The odor neutralization system includes a neutralizer storage tank and neutralizer delivery branches respectively provided in the sludge unloading closed bin and the sludge drying pretreatment closed workshop, each equipped with a plurality of atomizing nozzles. The sludge unloading closed bin is provided with a wet sludge storage bin. The biological inhibition system includes an inhibitor storage tank, which is connected to the wet sludge storage bin via an inhibitor delivery pipeline. The ventilation system includes an exhaust gas collection device respectively provided in the sludge unloading closed bin and the sludge drying pretreatment closed workshop, which is connected to the boiler secondary air delivery pipe via an odor delivery pipe. This invention can eliminate the problem of unorganized malodorous gas emissions that affect the health of personnel in coal-fired power plants and the quality of the surrounding environment.

Description

Technical Field

[0001] The present invention belongs to the field of treatment of malodorous gas from sludge co-combustion in coal-fired power plants, and particularly relates to a comprehensive system and method for removing odor from sludge drying and co-combustion in thermal power plants. Background Art

[0002] With sludge disposal now included in the unified regulation of urban wastewater treatment and emission reduction, sludge digestion has become a critical issue for sewage treatment plants. Traditional sludge disposal methods include landfill, composting, incineration, and sea evacuation. However, with tightening environmental protection policies and the near-capacity of landfills, sludge disposal issues are becoming increasingly serious. Traditional sludge incineration requires the construction of new boilers and other related equipment, resulting in high investment costs. Therefore, sludge drying and co-incineration in thermal power plants has become a new driver for urban sludge disposal.

[0003] With the commissioning of sludge drying and co-incineration projects at coal-fired power plants, large amounts of malodorous gases are generated by fermentation of sludge in wet sludge storage silos, as well as unorganized emissions of malodorous gases during sludge transportation, unloading, and transfer and drying pretreatment. The main components of these malodorous gases include hydrogen sulfide, ammonia, volatile organic compounds, and volatile nitrogen- and sulfur-containing organic compounds. This has led to a harsh operating environment in the sludge unloading storage area, sludge drying workshop, and surrounding equipment, seriously affecting the health of coal-fired power plant employees and the quality of the surrounding environment. Sludge drying and co-incineration projects at coal-fired power plants generally use negative pressure extraction to achieve odor removal, but this cannot eliminate the problem of unorganized malodorous gas emissions that affect operations and the quality of the surrounding environment. Summary of the Invention

[0004] The purpose of the present invention is to address the problem of unorganized malodorous gas emissions during the unloading, storage and drying pretreatment of wet sludge in the above-mentioned prior art, and to provide a comprehensive odor removal system and method for sludge drying and co-combustion in thermal power plants to eradicate malodorous gases.

[0005] In order to achieve the above object, the present invention has the following technical solutions:

[0006] A comprehensive odor removal system for sludge drying and co-combustion in thermal power plants, comprising a sludge unloading closed bin, a sludge drying pretreatment closed workshop, an odor neutralization system, a biological inhibition system, and a ventilation system;

[0007] The odor neutralization system includes a neutralizer storage tank and a neutralizer delivery branch pipe respectively arranged in the sludge unloading closed warehouse and the sludge drying pretreatment closed workshop, and a plurality of atomizing nozzles are installed on the neutralizer delivery branch pipe;

[0008] The sludge unloading closed bin is provided with a wet sludge storage bin, and the biological inhibition system includes an inhibitor storage tank, which is connected to the wet sludge storage bin via an inhibitor delivery pipeline;

[0009] The ventilation system includes exhaust and gas collecting devices respectively arranged in the sludge unloading closed bin and the sludge drying pretreatment closed workshop, and the exhaust and gas collecting devices are connected to the boiler secondary air conveying pipe through the odor conveying pipe.

[0010] As a preferred solution of the comprehensive removal system for odor from sludge drying and co-combustion in thermal power plants of the present invention, the sludge unloading closed bin is provided with a high-speed stacking door and a high-speed stacking door controller, wherein the high-speed stacking door controller can be manually controlled outside the sludge unloading closed bin or controlled by a remote control system.

[0011] As a preferred solution of the comprehensive odor removal system for sludge drying and co-combustion in thermal power plants of the present invention, the sludge unloading closed bin and the sludge drying pretreatment closed workshop are each provided with an odor gas online monitoring device.

[0012] As a preferred solution of the comprehensive odor removal system for sludge drying and co-combustion in thermal power plants of the present invention, the neutralizer delivery branch pipe is connected to the neutralizer storage tank through the neutralizer delivery pipe, and the two groups of neutralizer delivery branch pipes are arranged in a grid shape on the top of the sludge unloading closed bin and the sludge drying pretreatment closed workshop.

[0013] As a preferred solution of the comprehensive removal system for odor from sludge drying and co-combustion in thermal power plants of the present invention, a neutralizer delivery pipe is sequentially provided with a neutralizer delivery main valve and several neutralizer delivery pumps connected in parallel. The outlet pipes of the neutralizer delivery pumps are connected to two groups of neutralizer delivery branches through a flow measuring device after being connected. A neutralizer delivery branch valve is respectively provided between the flow measuring device and the two groups of neutralizer delivery branches.

[0014] As a preferred solution of the comprehensive odor removal system for drying and co-combustion sludge in thermal power plants of the present invention, the odor neutralization system and the ventilation system are interlocked in operation.

[0015] As a preferred solution of the comprehensive odor removal system for sludge drying and co-combustion in thermal power plants of the present invention, the exhaust and gas collection devices arranged in the sludge unloading closed bin and the sludge drying pretreatment closed workshop are respectively controlled by an exhaust shut-off door, and a plurality of parallel odor conveying fans are connected between the two exhaust shut-off doors through pipelines. A check valve is provided at the outlet of the odor conveying fan, and the outlet pipes of the odor conveying fan are connected to multiple boiler secondary air conveying pipes through air supply shut-off doors after the pipes are connected; a pressure measuring device and a flow measuring device are provided on the inlet pipe of the odor conveying fan.

[0016] As a preferred solution of the comprehensive odor removal system for sludge drying and co-combustion in thermal power plants of the present invention, the inhibitor storage tank is connected to the inhibitor delivery pumps connected in parallel through the inhibitor delivery main valve, and the outlet pipes of the inhibitor delivery pumps are connected to the wet sludge storage bin through a flow measuring device after being connected.

[0017] The present invention also provides a comprehensive method for removing odor from sludge drying and burning in thermal power plants, comprising the following steps:

[0018] - Unload the sludge in the closed sludge unloading bin, seal the closed sludge unloading bin, and simultaneously start the odor neutralization system and biological inhibition system in the closed sludge unloading bin;

[0019] -After unloading is completed, the sludge unloading closed bin will be closed again, and the odor neutralization system and ventilation system will regularly interlock the sludge unloading closed bin and the sludge drying pretreatment closed workshop to neutralize the odor and pump the odor to the boiler secondary air delivery pipe to maintain the unorganized odor gas in the sludge unloading closed bin and the sludge drying pretreatment closed workshop below the set concentration.

[0020] As a preferred solution of the comprehensive odor removal method for drying and co-combustion of sludge in thermal power plants of the present invention, the neutralizer delivery pump in the odor neutralization system, the inhibitor delivery pump in the biological inhibition system, and the odor delivery fan in the ventilation system are all operating equipment equipped with backup equipment.

[0021] Compared with the prior art, the odor comprehensive removal system of the present invention has at least the following beneficial effects:

[0022] During specific operations, the wet sludge transport truck unloads in the sludge unloading closed bin. When unloading, the odor neutralization system and the biological inhibition system in the sludge unloading closed bin are opened simultaneously. After unloading, the transport truck exits and the sludge unloading closed bin is closed again. Due to the addition of biological inhibitors, the generation of odor in the wet sludge storage bin is suppressed. A small amount of unorganized odor in the sludge unloading closed bin and the sludge drying pretreatment closed workshop is eliminated by regular spraying of odor neutralizers by the neutralization system and regular ventilation by the ventilation system. A small amount of odor-containing air is sent to the boiler secondary air system and then enters the boiler for incineration. The comprehensive odor removal system of the present invention adopts three methods to jointly treat odor. First, it suppresses the generation of odor. Secondly, it neutralizes the unorganized odor regularly and ventilates and extracts it. It can eradicate the unorganized emission of malodorous gases, which affects the health of coal-fired power plant personnel and the quality of the surrounding environment.

[0023] Compared with the prior art, the comprehensive odor removal method of the present invention has at least the following beneficial effects:

[0024] A wet sludge storage bin is provided in the sludge unloading closed bin. The addition of biological inhibitors to the wet sludge storage bin can effectively reduce the generation of malodorous gases, reducing the malodorous gas generation rate in the wet sludge storage bin by 70%. When the wet sludge is unloaded, the neutralization system is simultaneously turned on in the sludge unloading closed bin, which can effectively neutralize the unorganized malodorous gases emitted, ensuring that the malodorous gas concentration in the sludge unloading closed bin does not exceed the average value of the malodorous gas monitoring during non-unloading. The regular interlocking operation of the odor neutralization system and the ventilation system can ensure that the malodorous gas concentration in the sludge unloading closed bin or the sludge drying pretreatment closed workshop is lower than the plant boundary malodorous gas emission standard. It has been verified that the present invention can reduce the operating cost of the sludge drying and co-combustion odor removal system in thermal power plants by 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic structural diagram of a comprehensive system for removing odors from sludge drying and combustion in a thermal power plant according to an embodiment of the present invention;

[0026] In the attached figure: 1-sludge unloading closed bin; 2-sludge drying pretreatment closed workshop; 3-odor neutralization system; 4-biological inhibition system; 5-ventilation system; 6-neutralizer storage tank; 7-neutralizer delivery pump; 8-two sets of neutralizer delivery branches; 9-atomizing nozzle; 10-inhibitor delivery pump; 11-inhibitor storage tank; 12-wet sludge storage bin; 13-exhaust and gas collection device; 14-odor conveying fan; 15-boiler secondary air delivery pipe; 16-high-speed stacking door; 17-high-speed stacking door controller; 18-malodorous gas online monitoring device; 19-neutralizer delivery main valve; 20-neutralizer delivery branch valve; 21-first flow measuring device; 22-inhibitor delivery main valve; 23-second flow measuring device; 24-exhaust shut-off door; 25-check valve; 26-supply air shut-off door; 27-pressure measuring device; 28-third flow measuring device. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] See also Figure 1 The present invention provides a comprehensive odor removal system for sludge drying and co-combustion in thermal power plants, comprising a sludge unloading closed bin 1, a sludge drying pretreatment closed workshop 2, an odor neutralization system 3, a biological inhibition system 4, and a ventilation system 5.

[0029] The odor neutralization system 3 includes a neutralizer storage tank 6, a neutralizer delivery pump 7, a neutralizer delivery pipe, two sets of neutralizer delivery branches 8, and several atomizing nozzles 9. The atomizing nozzles 9 are connected to the outlets of the two sets of neutralizer delivery branches 8, the inlets of which are connected to the outlets of the neutralizer delivery pipes. The neutralizer delivery pipes are then connected to the neutralizer storage tank 6. The biological inhibition system 4 includes several inhibitor delivery pipes, an inhibitor delivery pump 10, and an inhibitor storage tank 11. The outlets of the inhibitor delivery pipes are connected to a wet sludge storage bin 12, and the inlets of the inhibitor delivery pipes are connected to the inhibitor storage tank 11. The ventilation system 5 includes two sets of exhaust and air collection devices 13, several odor delivery pipes, and an odor delivery fan 14. The inlets of the two sets of exhaust and gas collecting devices 13 are respectively connected to the sludge unloading closed bin 1 and the sludge drying pretreatment closed workshop 2, and the outlets of the two sets of exhaust and gas collecting devices 13 are connected to the inlets of the odor conveying pipes. After the odor conveying pipes are connected in combination, they are connected to the inlets of two odor conveying fans 14. After the outlets of the odor conveying fans 14 are connected in combination, they are connected to several boiler secondary air conveying pipes 15.

[0030] The neutralizer delivery pipe is provided with a connected neutralizer delivery main valve 19, a neutralizer delivery pump 7 and a neutralizer delivery branch pipe valve 20, wherein the neutralizer delivery main valve 19, the neutralizer delivery pump 7 and the neutralizer delivery branch pipe valve 20 are distributed in sequence along the neutralizer delivery direction; the inhibitor delivery pipeline is provided with a connected inhibitor delivery main valve 22 and an inhibitor delivery pump 10, wherein the inhibitor delivery main valve 22 and the inhibitor delivery pump 10 are distributed in sequence along the inhibitor delivery direction; the odor delivery pipe is provided with an exhaust shut-off door 24, an odor delivery fan 14, a check valve 25 and an air supply shut-off door 26, wherein the exhaust shut-off door 24, the odor delivery fan 14, the check valve 25 and the air supply shut-off door 26 are distributed in sequence along the odor delivery direction.

[0031] The sludge unloading closed bin 1 and the sludge drying pretreatment closed workshop 2 are each provided with an online malodorous gas monitoring device 18; the outlet pipes of the neutralizer delivery pump 7 are connected to the two sets of neutralizer delivery branches 8 through the first flow measuring device 21 after being connected; the outlet pipes of the inhibitor delivery pump 10 are connected to the wet sludge storage bin 12 through the second flow measuring device 23 after being connected; the outlet pipes of the two sets of exhaust and gas collecting devices 13 are connected to the odor blower 14 through the pressure measuring device 27 and the third flow measuring device 28 after being connected.

[0032] The sludge unloading closed bin 1 includes a high-speed stacking door 16 for closure and a high-speed stacking door controller 17 , wherein the high-speed stacking door controller 17 can be manually controlled outside the sludge unloading closed bin 1 or controlled by a remote control system.

[0033] Two groups of neutralizer delivery branch pipes 8 are arranged in a grid pattern on the top of the sludge unloading closed bin 1 and the sludge drying pretreatment closed workshop 2.

[0034] The odor neutralization system 3 and the ventilation system 5 operate interlocked.

[0035] During the specific operation of the present invention, the wet sludge transport vehicle unloads the sludge unloading closed bin 1. During unloading, the sludge unloading closed bin 1 is completely closed, and the odor neutralization system 3 and biological inhibition system 4 of the sludge unloading closed bin 1 are simultaneously opened. After unloading is completed, the transport vehicle withdraws and the sludge unloading closed bin 1 is closed again. The odor neutralization system 3 and the ventilation system 5 regularly interlock the sludge unloading closed bin 1 and the sludge drying pretreatment closed workshop 2 to neutralize the odor and pump the odor to the boiler secondary air delivery pipe 15 to ensure that the unorganized malodorous gas in the two closed workshops is maintained at a low concentration that does not affect the health of on-site operators. It should be noted that the neutralizer delivery pump 7, the inhibitor delivery pump 10 and the odor delivery fan 14 in the embodiment of the present invention all adopt a one-in-operation and one-in-standby configuration, and operate in standby mode with each other.

[0036] An online malodorous gas monitoring device 18 is installed in the sludge unloading closed warehouse 1 and the sludge drying pretreatment closed workshop 2, and the neutralizer spraying amount and the exhaust air exchange volume are adjusted in time according to the monitoring data to ensure the comprehensive treatment effect of the malodorous gas.

[0037] A first flowmeter 21 is installed on the parallel pipeline after the neutralizer delivery pump 7 to monitor the neutralizer delivery flow rate. Furthermore, the inlet pipes of the two sets of neutralizer delivery branches 8 are each equipped with a neutralizer delivery branch valve 20 to enable single-sided delivery of neutralizer to the sludge unloading closed bin 1 or the sludge drying pretreatment closed workshop 2.

[0038] A first flow measuring device 21 is installed on the parallel pipe after the inhibitor delivery pump 10 to monitor the inhibitor delivery flow rate.

[0039] The outlets of the two sets of exhaust and gas collection devices 13 are each equipped with an exhaust shutoff door 24 to enable single-sided odor extraction from the sludge unloading closed bin 1 or the sludge drying pretreatment closed workshop 2. A pressure measuring device 27 and a third flow measuring device 28 are installed on the parallel pipes behind the exhaust shutoff doors 24 to monitor the pressure and flow of malodorous gases. Furthermore, a check valve 25 is installed behind the odor conveying fan 14 to prevent odor backflow. A supply air shutoff door 26 is installed on the odor conveying branch before the boiler secondary air duct 15 to ensure odor delivery to a single boiler secondary air duct.

[0040] The present invention adopts three combined methods to treat odor. First, the generation of odor is suppressed. Second, the unorganized odor is neutralized and the air is exchanged and exhausted regularly. This can eradicate the problem of unorganized emission of malodorous gases that affects the operation and the quality of the surrounding environment. It can reduce the generation rate of malodorous gases in the wet sludge storage bin by 70% and reduce the cost of odor removal in sludge drying and co-combustion in thermal power plants by 30%.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and replacements, and these modifications and replacements are also within the scope of protection covered by the claims.

Claims

1. A comprehensive odor removal system for sludge drying and combustion in thermal power plants, characterized by: It includes a sludge unloading closed bin (1), a sludge drying pretreatment closed workshop (2), an odor neutralization system (3), a biological inhibition system (4) and a ventilation system (5); The odor neutralization system (3) includes a neutralizer storage tank (6) and a neutralizer delivery branch pipe (8) respectively arranged in the sludge unloading closed warehouse (1) and the sludge drying pretreatment closed workshop (2), and a plurality of atomizing nozzles (9) are installed on the neutralizer delivery branch pipe (8); The sludge unloading closed bin (1) is provided with a wet sludge storage bin (12), and the biological inhibition system (4) includes an inhibitor storage tank (11), and the inhibitor storage tank (11) is connected to the wet sludge storage bin (12) via an inhibitor delivery pipeline; The ventilation system (5) includes an exhaust gas collecting device (13) respectively arranged in the sludge unloading closed bin (1) and the sludge drying pretreatment closed workshop (2), and the exhaust gas collecting device (13) is connected to the boiler secondary air conveying pipe (15) through the odor conveying pipe; The exhaust air collecting devices (13) arranged in the sludge unloading closed bin (1) and the sludge drying pretreatment closed workshop (2) are respectively controlled by an exhaust air shutoff door (24); a plurality of odor conveying fans (14) connected in parallel are connected via a pipeline between the two exhaust air shutoff doors (24); a check valve (25) is provided at the outlet of the odor conveying fan (14); the outlet pipes of the odor conveying fan (14) are connected to a plurality of boiler secondary air conveying pipes (15) through air supply shutoff doors (26) after being combined; a pressure measuring device (27) and a third flow measuring device (28) are provided on the inlet pipe of the odor conveying fan (14); The neutralizer delivery branch pipe (8) is connected to the neutralizer storage tank (6) through the neutralizer delivery pipe, and the two groups of neutralizer delivery branch pipes (8) are arranged in a grid pattern on the top of the sludge unloading closed bin (1) and the sludge drying pretreatment closed workshop (2); A neutralizer delivery main valve (19) and a plurality of mutually parallel neutralizer delivery pumps (7) are sequentially arranged on the neutralizer delivery pipe. The outlet pipes of the neutralizer delivery pumps (7) are connected to each other through a first flow measuring device (21) and then communicated with the two groups of neutralizer delivery branch pipes (8). A neutralizer delivery branch pipe valve (20) is respectively arranged between the first flow measuring device (21) and the two groups of neutralizer delivery branch pipes (8). The odor neutralization system (3) and the ventilation system (5) are interlocked in operation; Adding biological inhibitors to the wet sludge storage bin (12) can reduce the generation rate of malodorous gases in the wet sludge storage bin; when the wet sludge is unloaded, the odor neutralization system (3) is synchronously opened in the sludge unloading closed bin (1) to neutralize the unorganized malodorous gases so that the malodorous gas concentration in the sludge unloading closed bin (1) does not exceed the average value of malodorous gas monitoring during non-unloading; the regular interlocking operation of the odor neutralization system (3) and the ventilation system (5) can make the malodorous gas concentration in the sludge unloading closed bin (1) or the sludge drying pretreatment closed workshop (2) lower than the factory boundary malodorous gas emission standard.

2. The comprehensive odor removal system for sludge drying and combustion in thermal power plants according to claim 1 is characterized by: The sludge unloading closed bin (1) is provided with a high-speed stacking door (16) and a high-speed stacking door controller (17), wherein the high-speed stacking door controller (17) can be manually controlled outside the sludge unloading closed bin (1) or controlled by a remote control system.

3. The comprehensive odor removal system for sludge drying and combustion in thermal power plants according to claim 1 is characterized by: The sludge unloading closed bin (1) and the sludge drying pretreatment closed workshop (2) are each provided with an odorous gas online monitoring device (18).

4. The comprehensive odor removal system for sludge drying and combustion in thermal power plants according to claim 1 is characterized by: The inhibitor storage tank (11) is connected to the inhibitor delivery pumps (10) connected in parallel via the inhibitor delivery main valve (22); the outlet pipes of the inhibitor delivery pumps (10) are connected to the wet sludge storage bin (12) via the second flow measuring device (23) after being connected.

5. A comprehensive method for removing odor from thermal power plant sludge drying and combustion, characterized in that: The comprehensive odor removal system for drying and incinerating sludge in a thermal power plant according to any one of claims 1 to 4 comprises the following steps: - Unloading the sludge in the closed sludge unloading bin (1), closing the closed sludge unloading bin (1), and simultaneously starting the odor neutralization system (3) and the biological inhibition system (4) in the closed sludge unloading bin (1); - After the unloading is completed, the sludge unloading closed bin (1) is closed again, and the odor neutralization system (3) and the ventilation system (5) regularly interlock the sludge unloading closed bin (1) and the sludge drying pretreatment closed workshop (2) to neutralize the odor and pump the odor to the boiler secondary air delivery pipe (15) to maintain the unorganized odorous gas in the sludge unloading closed bin (1) and the sludge drying pretreatment closed workshop (2) below the set concentration.

6. The method for comprehensive removal of odor from thermal power plant sludge drying and combustion according to claim 5, characterized in that: The neutralizer delivery pump (7) in the odor neutralization system (3), the inhibitor delivery pump (10) in the biological inhibition system (4), and the odor delivery fan (14) in the ventilation system (5) are all operating equipment equipped with backup equipment.

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