Downward combustion type household garbage cracking furnace

Abstract

The utility model discloses a down-burning type household garbage cracking furnace which comprises a down-burning type gasification furnace, a heat exchanger, an induced draft fan, a cyclone separator, a bag-type dust collector, a desulfurization and denitrification device and a cracking gas boiler, the down-burning type gasification furnace is a main body part of the cracking furnace and comprises a combustion chamber, a fire grate, a feeding valve plate and a combustor, and the feeding valve plate is arranged above a furnace body; the combustion chamber is arranged at the middle upper part of the furnace body and is divided into three parts, namely a drying area, a preheating area and a combustion area, the uppermost part is the drying area, the middle part is the preheating area, and a fire grate which is obliquely arranged is arranged below the combustion chamber and is used for placing comburent; a combustor is installed below the fire grate and used for the starting process of the down-burning type gasification furnace. By adopting the cracking furnace, the household garbage can be firstly generated into cracking gas under a controllable condition, and then the cracking gas is subjected to secondary high-temperature combustion, so that no dioxin substance is generated on the technical principle. And meanwhile, dust removal and flue gas treatment are combined to reduce qualified discharge of final emissions.

Description

Technical Field

[0001] The utility model relates to the field of cracking furnaces, in particular to a bottom-burning domestic garbage cracking furnace. Background Art

[0002] Domestic waste management has always been one of the focuses of social attention, and the mature application of large-scale domestic waste treatment devices has achieved remarkable results in urban areas. However, the promotion of this technology in rural and township areas is restricted by a series of problems. One of the most significant problems is the high investment cost of large-scale domestic waste treatment devices, which may be an unbearable burden for places with limited resources. Therefore, we urgently need a small-scale domestic waste treatment solution that is more suitable for distributed treatment.

[0003] At the current technological level, small-scale incinerators for domestic waste treatment are usually direct combustion treatment furnaces, which have some technical and environmental challenges. Although some equipment is equipped with subsequent flue gas treatment devices, it is difficult to effectively reduce the emission of harmful substances such as dioxins due to the limitation of technological level. This makes the current small-scale domestic waste treatment technology still have shortcomings in terms of environmental protection. Summary of the invention

[0004] In order to overcome the above technical defects, the purpose of the utility model is to provide a bottom-burning domestic waste cracking furnace, which first generates cracking gas from domestic waste under controllable conditions, and then performs secondary high-temperature combustion on the cracking gas, thereby ensuring that no dioxin substances are generated in technical principles. At the same time, dust removal and flue gas treatment are combined to reduce the qualified discharge of final emissions.

[0005] To this end, the utility model provides a bottom-burning domestic waste cracking furnace, comprising a bottom-burning gasification furnace 100, a heat exchanger 101, an induced draft fan 102, a cyclone separator 103, a bag dust collector 104, a desulfurization and denitration device 105, and a cracking gas boiler 106, wherein the outlet of the bottom-burning gasification furnace 100 is connected to the inlet of the heat exchanger 101, the outlet of the heat exchanger 101 is connected to the inlet of the induced draft fan 102, the outlet of the induced draft fan 102 is connected to the inlet of the cyclone separator 103, the outlet of the cyclone separator 103 is connected to the inlet of the bag dust collector 104, and the outlet of the bag dust collector 104 is connected to the inlet of the cracking gas boiler 106; the outlet of the cracking gas boiler 106 is connected to the inlet of the desulfurization and denitration device 105, and the outlet of the desulfurization and denitration device 105 is discharged to the air;

[0006] The induced draft fan 102 is used to extract the flue gas in the bottom-fired gasifier 100, the heat exchanger 101 is used to cool the flue gas, the cyclone separator 103 is used to separate large particles of smoke from the cooled flue gas, the bag filter 104 is used to separate small particles of smoke, so that the dust content in the flue gas meets the standard, the cracking gas boiler 106 is used to perform secondary combustion on the combustible gas components in the flue gas, and the desulfurization and denitrification device 105 is used to adsorb trace sulfides and nitrogen oxides in the combustion exhaust gas to finally obtain exhaust gas that meets the emission standards.

[0007] The bottom-fired gasifier 100 is the main part of the cracking furnace, including a combustion chamber 1, a grate 2, a feed valve plate 7, and a burner 8, wherein the feed valve plate 7 is arranged above the furnace body. When feeding is required, the feed valve plate 7 is opened and domestic garbage enters the bottom-fired gasifier 100; the combustion chamber 1 is arranged in the middle and upper part of the furnace body, and is divided into three parts: a drying area, a preheating area, and a combustion area. The top is the drying area, which uses the heat brought by the flue gas below to dry the domestic garbage. The middle is the preheating area, which uses the heat from the combustion area below to increase the temperature of the domestic garbage; an obliquely arranged grate 2 is provided below the combustion chamber 1 for placing combustibles; a burner 8 is installed below the grate 2 for the startup process of the bottom-fired gasifier 100.

[0008] Furthermore, an ultrasonic level meter 9 is installed above the furnace body to measure the current garbage capacity in the furnace body.

[0009] Furthermore, after the combustion process is stabilized, the burner 8 is turned off, and the combustion process is maintained by utilizing the incinerator's own heat source.

[0010] Furthermore, a small adjustable-speed blower 6 is installed below the grate 2 to supply air to the combustion area, and the operating speed of the blower 6 depends on the state of the combustion process.

[0011] Furthermore, two thermocouple sensors 4 and 5 are arranged on the side of the furnace body to monitor the combustion process. When a downward trend in temperature is found, the blower 6 is started to strengthen the combustion process to ensure a continuous and stable combustion process.

[0012] Furthermore, a reciprocating ash scraper 12 is provided under the grate 2, and the ash scraper 12 is controlled by a driving device 11 to move the ash to an ash storage bin 21 under the grate 2. The ash storage bin 21 is provided with an ash discharge door, and incombustible materials are discharged into the storage bin through a discharge port 22 at the lower side of the grate 2.

[0013] Furthermore, the induced draft fan is of variable frequency speed regulation mode, and the speed is adjusted according to the combustion state in the furnace body, so as to ensure that the bottom-fired gasification furnace 100 is in a negative pressure state.

[0014] Compared with the prior art, the above technical solution has the following beneficial effects:

[0015] The bottom-burning domestic waste cracking furnace proposed by the utility model can first generate cracking gas from domestic waste under controllable conditions, and then perform secondary high-temperature combustion on the cracking gas, thereby ensuring that no dioxin substances are generated in technical principles. At the same time, bag dust collectors are used for dust removal and flue gas treatment to reduce the qualified discharge of final emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the structural layout diagram of the bottom-burning domestic waste cracking furnace.

[0017] Figure 2 This is a three-dimensional structural diagram of a bottom-burning gasifier.

[0018] Figure 3 This is a side structural diagram of a bottom-burning gasifier.

[0019] Figure 4 This is the front structural diagram of the bottom-burning gasifier.

[0020] Among them, 1 is a combustion chamber, 2 is a grate, 4 is a thermocouple sensor, 5 is a thermocouple sensor, 6 is a blower, 7 is a feed valve plate, 8 is a burner, 9 is an ultrasonic level meter, 11 is a driving device, 12 is an ash scraper, 21 is an ash storage bin, 22 is a discharge port, 100 is a bottom-fired gasifier, 101 is a heat exchanger, 102 is an induced draft fan, 103 is a cyclone separator, 104 is a bag filter, 105 is a desulfurization and denitrification device, and 106 is a cracking gas boiler. DETAILED DESCRIPTION

[0021] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0022] like Figure 1As shown, the domestic garbage is initially crushed and sent to the combustion chamber 1 of the bottom-fired gasifier 100 from the top by a bucket elevator for primary combustion. The combustion process is carried out in the lower part of the combustion chamber 1, and through an oxygen-deficient combustion state, the combustion process can be stably and reliably executed under the action of the control system. Due to the oxygen-deficient combustion, combustible gas components such as carbon monoxide, hydrogen, and methane will be produced in its combustion products. At the same time, it is also accompanied by combustion flue gas products such as carbon dioxide. These combustion flue gases are first cooled by the heat exchanger 101, and then sent to the cyclone separator 103 under the action of the induced draft fan 102. Under the action of the cyclone separator 103, large particles of dust are first separated. Then the flue gas is further sent to the bag filter 104, and under the action of the bag filter 104, small particles of smoke in the flue gas are separated and controlled. In this way, a relatively clean cracking gas product is obtained. The pyrolysis gas is subjected to secondary combustion in the pyrolysis gas combustion boiler 106. On the one hand, the calorific value of the domestic waste is fully utilized. On the other hand, the dioxins and other harmful components generated in the primary combustion process can be decomposed through the high-temperature secondary combustion, thereby reducing the secondary pollution problem in the domestic waste treatment process. The tail gas after the secondary combustion is treated by the desulfurization and denitrification device 105 and then discharged.

[0023] The bottom-fired gasifier 100 is the main part of the system. Figure 2 As shown. A feed valve plate 7 is installed above the furnace body. When feeding is required, the feed valve plate 7 opens, and the elevator feeds the crushed domestic garbage into the furnace body. After the feeding is completed, the feed valve plate 7 closes. An ultrasonic level meter 9 is installed above the furnace body. The signal of the level meter can be used to know the current garbage capacity in the furnace body, thereby controlling the start and stop of the elevator.

[0024] The crushed domestic waste entering the furnace can be divided into three parts from top to bottom: drying area, preheating area, and combustion area. The top is the drying area, which uses the heat from the flue gas below to dry the domestic waste, thereby reducing the water content. Below it is the preheating area, which uses the heat from the combustion area below to increase the temperature of the domestic waste, so that it can enter the combustion state.

[0025] An obliquely arranged grate 2 is installed under the furnace body, and the combustion process is completed on the grate 2. Since the crushed domestic waste contains incombustibles such as stones and metals, and its volume is larger than the gap of the grate 2, it will accumulate on the grate 2 during the combustion process, thereby affecting the normal progress of the combustion process. A reciprocating ash scraper 12 is installed under the grate. Under the action of the ash scraper 12, these burned ashes will move to the ash storage bin 21 under the grate 2. The ash storage bin 21 opens the ash discharge door below at regular intervals to discharge ash. Incombustible materials such as stones are discharged into the storage bin from the discharge port 22 at the bottom of the grate 2.

[0026] An ignition burner 8 is installed below the grate 2. The burner 8 is used for the startup process of the bottom-fired gasifier 100 and can be turned off after the combustion process is stable. The combustion process is completely maintained by the incinerator's own heat source.

[0027] A small adjustable speed blower 6 is installed under the grate 2 to supply air to the combustion area. Its operating speed depends on the state of the combustion process. The combustion process is monitored by two thermocouple sensors 4 and 5 installed on the side of the furnace body. When the temperature in the furnace is found to be decreasing, the blower 6 is started to strengthen the combustion process, thereby ensuring that the combustion process is not interrupted.

[0028] In addition, the induced draft fan 102 at the rear of the bottom-fired gasifier 100 is also variable frequency speed regulation, which mainly ensures that the bottom-fired gasifier 100 is in a negative pressure state, thereby ensuring the stability of the combustion process. The speed adjustment also depends on the combustion state in the furnace body.

[0029] It should be noted that the embodiments of the utility model have better practicability and do not impose any form of limitation on the invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the invention without departing from the content of the technical solution of the invention are still within the scope of the technical solution of the invention.

Claims

1. A bottom-burning domestic waste cracking furnace, characterized in that: The invention comprises a bottom-fired gasifier (100), a heat exchanger (101), an induced draft fan (102), a cyclone separator (103), a bag dust collector (104), a desulfurization and denitration device (105), and a cracking gas boiler (106), wherein the outlet of the bottom-fired gasifier (100) is connected to the inlet of the heat exchanger (101), the outlet of the heat exchanger (101) is connected to the inlet of the induced draft fan (102), the outlet of the induced draft fan (102) is connected to the inlet of the cyclone separator (103), the outlet of the cyclone separator (103) is connected to the inlet of the bag dust collector (104), and the outlet of the bag dust collector (104) is connected to the inlet of the cracking gas boiler (106); the outlet of the cracking gas boiler (106) is connected to the inlet of the desulfurization and denitration device (105), and the outlet of the desulfurization and denitration device (105) is discharged to the air; The induced draft fan (102) is used to extract the flue gas in the bottom-fired gasification furnace (100); the heat exchanger (101) is used to cool the flue gas; the cyclone separator (103) is used to separate large particles of smoke from the cooled flue gas; the bag filter (104) is used to separate small particles of smoke; the cracking gas boiler (106) is used to perform secondary combustion on the combustible gas components in the flue gas; the desulfurization and denitrification device (105) is used to adsorb trace sulfides and nitrogen oxides in the combustion exhaust gas, so as to finally obtain exhaust gas that meets emission standards; The bottom-fired gasifier (100) is the main part of the cracking furnace, comprising a combustion chamber (1), a grate (2), a feed valve plate (7), and a burner (8), wherein the feed valve plate (7) is arranged above the furnace body. When feeding is required, the feed valve plate (7) is opened and domestic waste enters the bottom-fired gasifier (100); the combustion chamber (1) is arranged in the middle and upper part of the furnace body, and is divided into three parts: a drying area, a preheating area, and a combustion area. The top part is the drying area, which uses the heat brought by the flue gas below to dry the domestic waste. The middle part is the preheating area, which uses the heat brought by the combustion area below to increase the temperature of the domestic waste. An obliquely arranged grate (2) is arranged below the combustion chamber (1) for placing combustion materials. A burner (8) is installed below the grate (2) for starting the bottom-fired gasifier (100).

2. A bottom-burning domestic waste cracking furnace according to claim 1, characterized in that: An ultrasonic level meter (9) is installed above the furnace body to measure the current garbage volume in the furnace body.

3. A bottom-burning domestic waste cracking furnace according to claim 1, characterized in that: After the combustion process becomes stable, the burner (8) is turned off, and the combustion process is maintained by utilizing the incinerator's own heat source.

4. A bottom-burning domestic waste cracking furnace according to claim 1, characterized in that: A small adjustable-speed blower (6) is installed below the grate (2) to supply air to the combustion area. The operating speed of the blower (6) depends on the state of the combustion process.

5. The bottom-burning domestic waste cracking furnace according to claim 1, characterized in that: Two thermocouple sensors (4) and (5) are arranged on the side of the furnace body to monitor the combustion process. When a downward trend in temperature is found, the blower (6) is started to strengthen the combustion process, thereby ensuring a continuous and stable combustion process.

6. The bottom-burning domestic waste cracking furnace according to claim 1, characterized in that: An ash scraper (12) capable of reciprocating movement is arranged below the grate (2). The ash scraper (12) is controlled by a driving device (11) and is used to move ash into an ash storage bin (21) below the grate (2). The ash storage bin (21) is provided with an ash discharge door. Incombustible materials are discharged into the storage bin through a discharge port (22) at the lower side of the grate (2).

7. The bottom-burning domestic waste cracking furnace according to claim 1, characterized in that: The induced draft fan is of variable frequency speed regulation mode, and the speed is adjusted according to the combustion state in the furnace body, so as to ensure that the bottom-fired gasification furnace (100) is in a negative pressure state.

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