Tower type multi-stage grate staged gasification combustion furnace
By designing a tower-type multi-stage grate staged gasification combustion furnace, and adopting the alternating connection and falling motion of drying pyrolysis and gasification combustion chambers, the problem of low flexibility of rural domestic waste treatment equipment is solved, achieving efficient and flexible solid waste treatment and reducing equipment investment and maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHONGQING BINNAN ECOLOGICAL TECH CO LTD
- Filing Date
- 2023-04-28
- Publication Date
- 2026-05-12
AI Technical Summary
Existing solid waste incineration equipment is not flexible enough when processing rural domestic waste. The dispersion, dispersal and uniformity of solid waste are limited, the turning and stirring effects are poor, and the equipment is complex, requires a large investment, and is prone to problems such as material blockage and coking.
A tower-type multi-stage grate staged gasification combustion furnace was designed, including a drying pyrolysis chamber and a gasification combustion chamber. Through alternating connection and independent control, multi-stage sequential staged gasification is achieved. Solid waste is loosened during its movement in the furnace to avoid coking, and the combustion effect is optimized through a waste heat utilization chamber and an air supply mechanism.
It enables flexible processing of solid waste of different components and quantities, improves processing efficiency, reduces equipment investment and maintenance costs, and ensures complete combustion and harmless reduction.
Smart Images
Figure CN116293701B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solid waste incineration technology, specifically to a tower-type multi-stage grate staged gasification combustion furnace. Background Technology
[0002] Existing solid waste treatment technologies mainly include incineration, sanitary landfill, and composting. Incineration has many advantages, such as significant volume reduction, thorough harmlessness, small land occupation, and less secondary pollution, which aligns with my country's sustainable development strategy. Common incineration equipment includes mechanical grate incinerators and fixed-bed / vertical rotary gasification combustion furnaces. Staged gasification combustion technology utilizes the advantages of traditional direct incineration and pyrolysis gasification technologies. It sustains its pyrolysis gasification reaction through the heat generated from the combustion of syngas and residual char, eliminating the need for auxiliary heat sources. This makes the solid waste treatment process safer and more thorough, and it has gradually become the best choice for decentralized disposal of solid waste such as domestic waste, agricultural and forestry biomass, and its derived fuels and biomass briquettes in rural towns and sparsely populated western counties. Therefore, this technology is a solid waste treatment technology with great development potential.
[0003] Given the complex composition, diverse sources, and wide distribution of domestic solid waste in my country's rural areas, and the significant fluctuations in its quantity and composition due to seasonal and regional variations, especially its multi-scale nature, low calorific value, and high moisture content, existing incineration equipment still frequently encounters the following problems during operation:
[0004] 1. Given the complex composition, high moisture content, and low calorific value of solid waste in my country's townships, in order to ensure the normal operation of the pyrolysis gasification combustion process in the fixed bed / vertical rotary gasification combustion furnace, it is necessary to add pretreatment processes and equipment such as sorting, crushing, magnetic separation, and drying, which results in a large investment. At the same time, due to the numerous processes, it is easy to increase the number of failure points, and the use and maintenance costs will increase accordingly.
[0005] 2. The processing capacity of a single vertical rotary gasification combustion furnace is inflexible, and the capacity of each chamber is fixed. When dealing with solid waste materials with different compositions and contents, it is difficult to achieve the optimal solution.
[0006] 3. The internal thermochemical reaction space and slag discharge pyrolysis gasification chamber of the furnace are small, the loosening, stirring and mixing mechanism is not effective, the uniformity of material distribution is difficult to guarantee, and the physical and chemical properties of solid waste are severely unevenly distributed. At the same time, under the pyrolysis gasification process conditions, solid waste in the furnace is also prone to coking and agglomeration.
[0007] To address the aforementioned issues, the following patents exist: Patent 1 describes a large-capacity, high-load dual-furnace waste incineration device (CN216591722U). This device employs a symmetrically arranged dual-furnace structure, with two drying grates and a combustion grates symmetrically positioned at the bottom of the furnace, forming a combustion space within a single furnace. Patent 2 describes an integrated fixed-bed solid waste high-efficiency gasification combustion furnace. Within a single furnace body, a fixed-bed gasification section, a drying pyrolysis section, and a combustible gas combustion section are coaxially arranged from bottom to top. A slag discharge port is located at the bottom of the fixed-bed gasification section, and the grate has a 3-7 layer pagoda-shaped ventilation structure.
[0008] However, applying these findings to the disposal of solid waste in small towns presents challenges: numerous processing steps and equipment, complex process control, a large furnace structure, and substantial investment in plant and equipment. The use of a single vertical pyrolysis gasification furnace with a narrow slag discharge channel also increases the risk of material blockage. Compared to traditional grate incineration technology, gasification combustion technology produces fewer pollutants and less flue gas, resulting in lower flue gas purification costs. Summary of the Invention
[0009] The present invention aims to provide a miniaturized tower-type multi-stage grate staged gasification combustion furnace for the disposal of solid waste in rural areas, in order to solve the problems of low flexibility in solid waste treatment, limited dispersion, dispersibility and uniformity of solid waste, and poor turning and stirring effects in existing solid waste incineration devices.
[0010] To achieve the above objectives, the present invention provides the following technical solution:
[0011] The tower-type multi-stage grate staged gasification combustion furnace includes a furnace body and an air supply mechanism. The furnace body contains a pyrolysis gasification chamber. Drying pyrolysis chambers are connected to both sides above the pyrolysis gasification chamber, and gasification combustion chambers are connected to both sides below the pyrolysis gasification chamber. A drying pyrolysis furnace control gate is installed between the two drying pyrolysis chambers. A pyrolysis gasification furnace control gate is also installed between the pyrolysis gasification chamber and each of the two gasification combustion chambers. A drying pyrolysis grate is installed inside the drying pyrolysis chamber to push the incinerated material into the pyrolysis gasification chamber. An inlet connected to the drying pyrolysis grate is opened on the top of the drying pyrolysis chamber. An ash discharge port is opened at the bottom of the gasification combustion chamber. A gasification combustion burnout grate is installed between the pyrolysis gasification chamber and the ash discharge port to push the combustion ash to the ash discharge port. Both the drying pyrolysis grate and the gasification combustion burnout grate are push-type grates.
[0012] The principle of this scheme is as follows:
[0013] The two drying pyrolysis chambers and two gasification combustion chambers in this scheme can be alternately connected, connected on one side, or used simultaneously by all four chambers, depending on the amount of solid waste to be treated and the drying pyrolysis and pyrolysis gasification conditions. During solid waste treatment, the solid waste is fed into the drying pyrolysis chamber through the inlet. It is conveyed and agitated by the movement of the drying pyrolysis grate within the chamber, then falls into the pyrolysis gasification chamber. During this process, the solid waste is dried by the gas within the drying pyrolysis chamber, and some of it undergoes pyrolysis gasification. The solid waste entering the pyrolysis gasification chamber accumulates and layers, continuing the pyrolysis gasification reaction under the influence of radiant heat from the furnace, combustion heat, and primary air in the gasification combustion chamber, achieving layered combustion of the solid waste. The solid waste residue after pyrolysis gasification continuously enters the gasification combustion chamber under the movement of the gasification combustion burnout grate, where it is completely burned and extinguished under the influence of the gasification combustion burnout grate, furnace radiant heat, and secondary air, ultimately becoming ash and being discharged from the ash discharge port.
[0014] The beneficial effects of this plan are:
[0015] 1. This scheme is designed with two drying pyrolysis chambers and two gasification combustion chambers, and five independent chambers are integrated into one unit. By opening and closing the control gates of the drying pyrolysis furnace and the pyrolysis gasification furnace, the two drying pyrolysis chambers, the two gasification combustion chambers, and the pyrolysis gasification chamber can be alternately connected, and single / double chamber pyrolysis drying and single / double chamber gasification combustion can be achieved. The disposal path can be flexibly selected according to the properties and processing volume of solid waste. It has a large processing capacity, can realize bidirectional feeding and discharging, and can be controlled by chambers. It is easy to adjust the atmosphere inside the furnace to ensure the drying process and effect.
[0016] 2. Five independent chambers are designed and integrated into one unit to achieve multi-stage sequential gasification. The space is used rationally, which helps to control the overall width of the furnace body, reduce the overall height of the furnace body, and ensure the process effect and the amount of solid waste processed. It is also beneficial for the treatment of solid waste with high moisture content and low calorific value.
[0017] 3. The internal space design and distribution are reasonable. Based on the grate incinerator, a vertical combustion furnace structure is integrated. There is no grate in the pyrolysis gasification chamber. The movement of solid waste in the pyrolysis gasification chamber undergoes a fundamental change. It becomes loose through falling motion, which is conducive to the full action of furnace radiant heat, combustion heat and gas. This increases the looseness of solid waste and the completeness of combustion, prevents solid waste from coking and clumping, and reduces the probability of poor slag discharge and mechanical jamming.
[0018] 4. This solution integrates the drying pyrolysis grate of the grate furnace, allowing solid waste to be directly burned in the furnace without any pretreatment, achieving rapid combustion and high efficiency. For solid waste with high moisture content and low calorific value, it can be dried and pyrolyzed in two separate drying pyrolysis chambers and burned in two separate gasification combustion chambers, ensuring the incineration process and efficiency of solid waste with high moisture content and low calorific value.
[0019] 5. The design of the pyrolysis gasification chamber facilitates the full pyrolysis and gasification of complex, high-moisture, and low-calorific-value solid wastes. This allows the large molecules of organic components in the solid wastes to break down and be converted into small-molecule combustion gases and fuels, which is beneficial for subsequent gasification combustion and the harmlessness and reduction of solid wastes.
[0020] This solution differs from our comparison document in the following ways:
[0021] 1. In Patent 1, the drying grate and the combustion grate correspond to two independent processes of pyrolysis and combustion of solid waste in the material layer, respectively, without pyrolysis reaction. However, in this scheme, the main / auxiliary drying pyrolysis grate mainly realizes the drying of solid waste and a small amount of pyrolysis reaction.
[0022] 2. Patent 1 adopts a symmetrical arrangement of two furnace chambers, with two drying grates and a combustion grates symmetrically arranged at the bottom of the furnace chamber, forming a combustion space of one furnace chamber. When viewed alone, it is exactly the same as the traditional two-section grate, and the solid waste still moves and burns along the grate. However, this solution has multiple chambers, including a main drying pyrolysis chamber, a secondary drying pyrolysis chamber, a pyrolysis gasification chamber, and a gasification combustion chamber. The solid waste falls from the main drying pyrolysis chamber and the secondary drying pyrolysis chamber into the pyrolysis gasification chamber. The movement mode of the solid waste changes fundamentally. It becomes loose through falling motion, which increases the looseness of the solid waste and the completeness of combustion.
[0023] 3. This scheme also includes a pyrolysis gasification + gasification combustion chamber. The pyrolysis gasification chamber facilitates the full pyrolysis and gasification of waste, making it ideal for complex, high-moisture, low-calorific-value township waste. This process breaks down large molecules of organic components in the waste, converting them into smaller molecules of combustible gases such as combustion gases and fuel oils. This facilitates complete combustion in the subsequent gasification combustion chamber and promotes the harmless and reduced-volume treatment of all waste materials. The space and dimensions of the pyrolysis gasification chamber are rationally designed to ensure the smooth flow of waste, water vapor, and combustible gases from top to bottom, which is conducive to the full pyrolysis and gasification of waste.
[0024] 4. In Patent 2, a single furnace body is coaxially arranged from bottom to top with a fixed-bed gasification section, a drying pyrolysis section, and a combustible gas combustion section, with the gas flow direction from bottom to top, which is an upward suction type. This solution, however, features multiple furnace chambers and multiple functions, with a downward suction gas flow direction. When processing solid waste, it is easier to generate more combustible gases with higher calorific value. The grate structure and pyrolysis gasification chamber used in this solution effectively address the issue of higher ash content inherent in downward suction types.
[0025] Furthermore, the feed inlet is connected to a hopper, and a discharge valve is installed at the connection point.
[0026] Beneficial effects: The silo is used to temporarily store solid waste. After the discharge valve is opened, it can automatically and continuously discharge materials for a short period of time. The discharge valve can make the mechanical seal of the inlet and the material seal of the silo work simultaneously, so as to make the sealing effect better, ensure the controllability of the atmosphere inside the furnace, and ensure the drying process.
[0027] Furthermore, a diversion tower is installed at the bottom of the pyrolysis gasification chamber, and a combustion air inlet is opened on the diversion tower.
[0028] Beneficial effects: 1. Solid waste in the pyrolysis gasification chamber is diverted and guided by the diversion tower, allowing it to move more smoothly and evenly to the gasification combustion grate, which is conducive to forming a balanced reaction process. It also prevents solid waste from coking and agglomerating in the pyrolysis gasification chamber, reducing the chance of poor discharge of solid waste and mechanical jamming. 2. The combustion air inlet on the diversion tower can introduce hot air from the air supply mechanism into the pyrolysis gasification chamber, ensuring combustion effect.
[0029] Furthermore, both the drying pyrolysis grate and the gasification combustion burnout grate are inclined. The angle between the single grate surface of the drying pyrolysis grate and the horizontal plane is 0 degrees, and the overall grate surface is inclined at 16-18 degrees to the horizontal plane. The lower end of the drying pyrolysis grate is connected to the pyrolysis gasification chamber, and the lower end of the gasification combustion burnout grate is connected to the ash discharge port, while the upper end is connected to the pyrolysis gasification chamber.
[0030] Beneficial effects: The drying pyrolysis grate and the gasification combustion burnout grate are set at an angle, and the overall grate surface is inclined at an angle of 16-18 degrees to the horizontal plane. The optimal grate stroke corresponds to 16-18 degrees, which can ensure that solid waste has sufficient residence time on the drying pyrolysis grate, and the drying effect can be achieved as expected (moisture content of about 30%). The tilting effect on the basis of grate movement can push solid waste more smoothly, prevent solid waste from coking and agglomerating on the grate, and improve operating efficiency.
[0031] Furthermore, the air supply mechanism includes a low-temperature flue gas passage for the drying section, a primary air passage for the gasification combustion section, a secondary air inlet, and a flue gas circulation passage. The secondary air inlet is located on the gasification combustion chamber, and a temperature sensor is installed in the low-temperature flue gas passage for the drying section. A waste heat utilization chamber is located inside the side wall of the furnace body. One end of the waste heat utilization chamber is connected to the flue gas circulation passage, and the other end of the waste heat utilization chamber has a medium-temperature flue gas outlet. The primary air passage for the gasification combustion section is located inside the outer wall of the waste heat utilization chamber.
[0032] Beneficial effects: 1. A waste heat utilization chamber is set up inside the side wall of the furnace. The high-temperature flue gas generated by the combustion of solid waste in the gasification combustion chamber is introduced into the waste heat utilization chamber through the flue gas circulation channel. This can keep the drying pyrolysis chamber warm and ensure the drying process and effect. 2. By introducing the high-temperature flue gas generated in the gasification combustion chamber into the waste heat utilization chamber, and setting the primary air channel of the gasification combustion section inside the outer side wall of the waste heat utilization chamber, the flue gas entering the waste heat utilization chamber can not only keep the drying pyrolysis chamber warm, but also heat the primary air in the low-temperature flue gas channel of the drying section. The heated primary air is then introduced into the gasification combustion chamber, which is more conducive to the combustion reaction and ensures the combustion process and effect.
[0033] Furthermore, the waste heat utilization chamber is equipped with several turbulence baffles, which divide the waste heat utilization chamber into an S-shape; the primary air duct of the gasification combustion section is also arranged in an S-shape.
[0034] Beneficial effects: 1. The baffles create an S-shaped flue gas flow path within the waste heat utilization chamber. High-temperature flue gas flows along this path, extending its residence time and facilitating the full utilization of its heat, thus improving the insulation of the drying pyrolysis chamber and the heating effect of the primary air. 2. Particulate matter in the high-temperature flue gas is trapped within the waste heat utilization chamber after being blocked by multiple baffles, reducing dust emissions at the medium-temperature flue gas outlet. Furthermore, the heat from the trapped high-temperature dust is recovered, further enhancing the heat recovery effect within the chamber. 3. The S-shaped arrangement of the primary air duct in the gasification combustion section creates an S-shaped airflow path. The primary air flowing along this path extends its residence time within the outer wall of the waste heat utilization chamber, ensuring effective heat exchange between the primary air and the high-temperature flue gas within the chamber.
[0035] Furthermore, a pressure sensor is installed on the furnace body, and a temperature sensor is installed inside the furnace body.
[0036] Beneficial effects: The installation of pressure and temperature sensors allows staff to accurately know the temperature of each reaction section and the pressure inside the furnace, enabling real-time temperature and pressure control.
[0037] Furthermore, slag discharge channels are provided below the drying pyrolysis grate, the standby drying pyrolysis grate, and the combustion grate, and these channels run through the inside and outside of the furnace body.
[0038] Beneficial effects: By inserting a tool into the slag discharge channel and pushing it from the outside in, the ash below the drying pyrolysis grate and the gasification combustion burnout grate can be pushed into the furnace body, thereby removing ash and preventing excessive ash from interfering with the grate movement and hindering the transfer of heat and hot air.
[0039] Furthermore, the drying pyrolysis chamber can dry materials independently. When the moisture content of the material reaches 20-30%, the control gate of the drying pyrolysis furnace is opened. When the newly fed material reaches the lower end of the drying pyrolysis grate, the regulating gate of the drying pyrolysis furnace is closed. When the gasification time is 30-45 minutes, one or two control gates of the pyrolysis gasification furnace are opened to realize the intermittent alternation of the two gasification combustion chambers.
[0040] Beneficial effects: The design incorporates two drying pyrolysis chambers. One chamber can be used alone for drying and pyrolysis of materials, which is beneficial for treating solid waste with high moisture content and low calorific value. When the high moisture content and low calorific value solid waste reaches the desired drying effect (20-30% moisture content) in a single drying pyrolysis chamber, the furnace regulating gate is opened to transport the dried solid waste to the gasification combustion chamber. Simultaneously, new material is introduced into this drying pyrolysis chamber. When the new material reaches the low-end discharge port of the drying pyrolysis grate in this chamber, all the dried solid waste enters the gasification combustion chamber. The furnace regulating gate is then closed, and the new material is dried and pyrolyzed separately. Alternatively, a single gasification combustion chamber can be used. When the gasification time is 30-45 minutes, and depending on the material level, one or two pyrolysis gasification furnace control gates can be opened as needed to achieve intermittent alternation of operation between the two gasification combustion chambers. Attached Figure Description
[0041] Figure 1 This is a longitudinal sectional view of an embodiment of the present invention, taken from the front, and includes a waste heat recovery chamber;
[0042] Figure 2 This is a left view of an embodiment of the present invention;
[0043] Figure 3 for Figure 2 A cross-sectional view of the furnace body (AA), the internal structure of the furnace body is not shown in the figure;
[0044] Figure 4 for Figure 3 A schematic diagram of the internal structure of the waste heat utilization chamber. Detailed Implementation
[0045] The following detailed description illustrates the specific implementation method:
[0046] The reference numerals in the accompanying drawings include: furnace body 1, drying pyrolysis chamber 11, drying pyrolysis furnace control gate 12, pyrolysis gasification chamber 13, ash discharge port 14, gasification combustion chamber 16, pressure sensor 18, slag discharge channel 19, pyrolysis gasification furnace control gate 110, primary air channel of gasification combustion section 2, secondary air inlet 21, drying pyrolysis grate 3, movable grate bar 31, fixed grate bar 32, gasification combustion burnout grate 4, feed port 6, unloading valve 61, silo 62, low temperature flue gas channel of drying section 7, flue gas circulation channel 81, waste heat utilization chamber 82, medium temperature flue gas outlet 83, baffle plate 84, diversion tower 9, and combustion air outlet 91.
[0047] Example:
[0048] like Figure 1 , Figure 2 and Figure 3 As shown, the tower-type multi-stage grate staged gasification combustion furnace includes a furnace body 1 and an air supply mechanism. The furnace body 1 includes two upper drying pyrolysis chambers 11 and two lower gasification combustion chambers 16. The drying pyrolysis chambers 11 and the gasification combustion chambers 16 are connected, and the connection point is a pyrolysis gasification chamber 13. A drying pyrolysis furnace control gate 12 is hinged between the two drying pyrolysis chambers 11, and a pyrolysis gasification furnace control gate 110 is hinged between the pyrolysis gasification chamber 13 and the two gasification combustion chambers 16. Pressure sensors 18 are installed on the side walls of the drying pyrolysis chambers 11 and the gasification combustion chambers 16, and multiple temperature sensors are installed inside the drying pyrolysis chambers 11 and the gasification combustion chambers 16.
[0049] Each of the two drying pyrolysis chambers 11 is equipped with a drying pyrolysis grate 3, which is inclined. Two feed inlets 6 are located at the top of each drying pyrolysis chamber 11. The high ends of the two drying pyrolysis grate 3 are connected to the feed inlets 6, and the low ends are connected to the pyrolysis gasification chamber 13. Both feed inlets 6 are connected to a hopper 62, and a discharge valve 61 is rotatably installed at the connection point. In this embodiment, the discharge valve 61 can be a butterfly valve. Each of the two gasification combustion chambers 16 is equipped with a gasification combustion burnout grate 4, which is inclined. The high ends of both gasification combustion burnout grate 4 are connected to the pyrolysis gasification chamber 13, and the low ends are connected to two ash discharge ports 14 located at the bottom of the gasification combustion chamber 16. A diversion tower 9 is provided at the bottom of the pyrolysis gasification chamber 13. In this embodiment, the diversion tower 9 is triangular and divides the pyrolysis gasification chamber 13 into an inverted "Y" shape, that is, the bottom of the pyrolysis gasification chamber 13 is divided into two channels that are connected to two gasification combustion burnout grates 4 respectively. A combustion air inlet 91 is opened on the diversion tower 9.
[0050] Both the drying pyrolysis grate 3 and the gasification combustion burnout grate 4 are push-type grates, each including multiple rows of fixed grate bars 32 and multiple rows of movable grate bars 31. The fixed grate bars 32 and movable grate bars 31 are alternately arranged. The fixed grate bars 32 are fixed to the frame by bolts, etc. The movable grate bars 31 are driven by a drive mechanism to reciprocate on the fixed grate bars 32. The drive mechanism can be a cylinder and linkage mechanism as used in the prior art. Both the drying pyrolysis grate 3 and the gasification combustion burnout grate 4 have slag discharge channels 19 at the bottom, which transversely penetrate the inside and outside of the furnace body 1. The angle of inclination of a single grate surface of the drying pyrolysis grate 3 and the gasification combustion burnout grate 4 to the horizontal plane is 0 degrees, and the overall grate surface angle of inclination to the horizontal plane is 16-18 degrees, preferably 17 degrees in this embodiment.
[0051] Combination Figure 4 As shown, the air supply mechanism includes a low-temperature flue gas passage 7 for the drying section, a primary air passage 2 for the gasification combustion section, a secondary air inlet 21, and a flue gas circulation passage. The secondary air inlet 21 is located on the gasification combustion chamber 16, and is inclined at an angle of 15°. A burner (not shown in the figure) is installed below the secondary air inlet 21, and the burner adopts the burner of the prior art. Each of the two drying pyrolysis chambers 11 is connected to a low-temperature flue gas passage 7 for the drying section, and a temperature sensor is installed in each of the two low-temperature flue gas passages 7. Waste heat utilization chambers 82 are opened in the front and rear side walls of the furnace body 1. The right end of the front waste heat utilization chamber 82 is connected to the flue gas circulation passage 81, and the left end has a medium-temperature flue gas outlet 83. The left end of the rear waste heat utilization chamber 82 is connected to the flue gas circulation passage 81, and the right end has a medium-temperature flue gas outlet 83. Several turbulence baffles 84 are welded in the waste heat utilization chamber 82, and the turbulence baffles 84 divide the waste heat utilization chamber 82 into an S-shape. The two waste heat utilization chambers 82 are each equipped with the aforementioned gasification combustion section primary air duct 2 on the outer wall. The gasification combustion section primary air duct 2 is S-shaped. The two gasification combustion section primary air ducts 2 converge at the bottom and connect to the gasification combustion chamber 16, using the air supplied from below the gasification combustion burnout grate 4.
[0052] The specific implementation process is as follows:
[0053] This solution has multiple disposal paths. In actual application, the disposal path of solid waste can be flexibly selected according to the amount of solid waste to be processed, moisture content, fuel characteristics, etc. It can use one drying pyrolysis chamber 11 and one gasification combustion chamber 16 alone, one drying pyrolysis chamber 11 with two gasification combustion chambers 16, or two drying pyrolysis chambers 11 and two gasification combustion chambers 16 in full open.
[0054] For example, for solid waste with high moisture content and low calorific value, one of the drying pyrolysis chambers 11 can be used to dry and pyrolyze the solid waste separately. Taking the drying pyrolysis chamber 11 on the left as an example, when the material reaches the expected drying effect, that is, when the moisture content of the material reaches 20-30%, the upper drying pyrolysis furnace control gate 12 turns to the right, opening the left drying pyrolysis chamber 11 and conveying the dried solid waste to the gasification combustion chamber 16. At the same time, new material is introduced into the drying pyrolysis chamber 11. When the new material is conveyed to the lower end of the drying pyrolysis grate 3 in the drying pyrolysis chamber 11, that is, all the dried solid waste enters the gasification combustion chamber 16, and the pyrolysis gasification furnace control gate 12 turns to the left to close the drying pyrolysis chamber 11, and the new material is dried and pyrolyzed separately. Alternatively, a single gasification combustion chamber 16 can be used. When the gasification time is 30 to 45 minutes, and depending on the material level, one or two pyrolysis gasification furnace control gates 110 can be opened in a timely manner to achieve intermittent alternation of operation of the two gasification combustion chambers 16.
[0055] For situations with large processing volumes, the control gate 12 of the drying pyrolysis furnace can be opened to utilize the two drying pyrolysis chambers 11 for dual-chamber drying and the two gasification combustion chambers 16 for dual-chamber combustion, ensuring the drying process, effect, and efficiency.
[0056] For solid waste with moderate moisture content and calorific value, or in cases where the processing volume is small, the control gates 12 of both drying pyrolysis furnaces can be turned to the left to close the left drying pyrolysis chamber 11 and the left gasification combustion chamber 16, while the right drying pyrolysis chamber 11 and the right gasification combustion chamber 16 can be used alone to dispose of the solid waste.
[0057] This embodiment specifically illustrates the solid waste treatment process with both drying pyrolysis chambers 11 and both gasification combustion chambers 16 fully open:
[0058] When processing solid waste, it is first poured into the silo 62. The solid waste accumulates in the silo 62. When it is necessary to feed material into the drying pyrolysis chamber 11, the discharge valve 61 is opened. Each opening of the discharge valve 61 completes one discharge. After entering the drying pyrolysis chamber 11, the solid waste falls onto the forward-pushing drying pyrolysis grate 3. Under the reciprocating motion of the movable grate plates 31, it is conveyed and agitated, and fully dried and undergoes localized pyrolysis under the radiant heat of the low-temperature flue gas and the high-temperature flue gas in the waste heat utilization chamber 82, releasing water vapor and producing a small amount of pyrolysis gas. The dried solid waste falls from the discharge end of the drying pyrolysis grate 3 into the pyrolysis gasification chamber 13, where it continues to undergo pyrolysis and gasification under the radiant heat of the furnace in the gasification combustion chamber 16, the heat of gas-phase combustion, and the heated primary air, producing syngas. Simultaneously, the water vapor passing through this material layer also enhances the gasification process, further increasing the syngas production. The mixture of solid waste residue from pyrolysis and gasification, along with a small amount of primary solid waste, continuously enters the gasification combustion grate 4, where it comes into extensive contact with heated primary air. Under the influence of furnace radiant heat, gas-phase combustion heat, and grate movement, a complete gasification combustion reaction occurs, turning the waste into ash. This ash is then discharged through the gasification combustion grate 4 and the ash discharge port, thus completing the solid waste disposal process. Simultaneously, the combustible gases in the flue gas are completely combusted in the gasification combustion chamber 16 under the action of secondary air. After sufficient residence, the high-temperature flue gas enters the waste heat utilization chamber 82 and is finally discharged from the medium-temperature flue gas outlet 83. After undergoing flue gas desulfurization and purification to meet emission standards, it is either discharged as low-temperature flue gas into the drying pyrolysis chamber 11 to continue drying the solid waste to be disposed of next.
[0059] This solution features multiple furnace chambers and multiple functions, with a downward gas flow direction. When treating solid waste, it is easier to generate more combustible gases with higher calorific value. The grate structure and pyrolysis gasification chamber adopted in this solution can effectively address the issue of higher ash content associated with downward gas flow.
[0060] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A tower-type multi-stage grate staged gasification combustion furnace, characterized in that: The furnace includes a furnace body and an air supply mechanism. The furnace body contains a pyrolysis gasification chamber. Drying pyrolysis chambers are connected to both sides above the pyrolysis gasification chamber, and gasification combustion chambers are connected to both sides below the pyrolysis gasification chamber. A drying pyrolysis furnace control gate is installed between the two drying pyrolysis chambers. A pyrolysis gasification furnace control gate is also installed between the pyrolysis gasification chamber and each of the two gasification combustion chambers. A drying pyrolysis grate is installed inside the drying pyrolysis chamber to push the incinerated material into the pyrolysis gasification chamber. An inlet connected to the drying pyrolysis grate is opened on the top of the drying pyrolysis chamber. An ash discharge port is opened at the bottom of the gasification combustion chamber. A gasification combustion burnout grate is installed between the pyrolysis gasification chamber and the ash discharge port to push the combustion ash to the ash discharge port. Both the drying pyrolysis grate and the gasification combustion burnout grate are push-type grates.
2. The tower-type multi-stage grate staged gasification combustion furnace according to claim 1, characterized in that: The inlet is connected to a hopper and a discharge valve is installed at the connection point.
3. The tower-type multi-stage grate staged gasification combustion furnace according to claim 2, characterized in that: A diversion tower is installed at the bottom of the pyrolysis gasification chamber, and a combustion air inlet is opened on the diversion tower.
4. The tower-type multi-stage grate staged gasification combustion furnace according to any one of claims 1-3, characterized in that: Both the drying pyrolysis grate and the gasification combustion burnout grate are inclined. The angle between the single grate surface of the drying pyrolysis grate and the horizontal plane is 0 degrees, and the overall grate surface is inclined at 16-18 degrees to the horizontal plane. The lower end of the drying pyrolysis grate is connected to the pyrolysis gasification chamber, and the lower end of the gasification combustion burnout grate is connected to the ash discharge port, while the upper end is connected to the pyrolysis gasification chamber.
5. The tower-type multi-stage grate staged gasification combustion furnace according to claim 1, characterized in that: The air supply mechanism includes a low-temperature flue gas passage for the drying section, a primary air passage for the gasification combustion section, a secondary air inlet, and a flue gas circulation passage. The secondary air inlet is located on the gasification combustion chamber, and a temperature sensor is installed in the low-temperature flue gas passage for the drying section. A waste heat utilization chamber is located inside the side wall of the furnace body. One end of the waste heat utilization chamber is connected to the flue gas circulation passage, and the other end of the waste heat utilization chamber has a medium-temperature flue gas outlet. The primary air passage for the gasification combustion section is located inside the outer wall of the waste heat utilization chamber.
6. The tower-type multi-stage grate staged gasification combustion furnace according to claim 5, characterized in that: The waste heat utilization chamber is equipped with several turbulence baffles, which divide the waste heat utilization chamber into an S-shape; the primary air duct of the gasification combustion section is also arranged in an S-shape.
7. The tower-type multi-stage grate staged gasification combustion furnace according to claim 6, characterized in that: A pressure sensor is installed on the furnace body, and a temperature sensor is installed inside the furnace body.
8. The tower-type multi-stage grate staged gasification combustion furnace according to claim 7, characterized in that: A slag discharge channel is provided below the drying pyrolysis grate and the combustion grate, and the slag discharge channel runs through the inside and outside of the furnace body.
9. The tower-type multi-stage grate staged gasification combustion furnace according to claim 1, characterized in that: The drying pyrolysis chamber can dry materials independently. When the moisture content of the material reaches 20-30%, the control gate of the drying pyrolysis furnace is opened. When the newly fed material reaches the lower end of the drying pyrolysis grate, the regulating gate of the drying pyrolysis furnace is closed. When the gasification time is 30-45 minutes, one or two control gates of the pyrolysis gasification furnace are opened to realize the intermittent alternation of the two gasification combustion chambers.