Small household garbage incinerator and using method

Abstract

The invention belongs to the technical field of incinerator equipment, and particularly relates to a small household garbage incinerator and a using method.The incinerator comprises a drying pyrolysis chamber and a combustion chamber which are arranged on a fire grate set of the garbage incinerator; the upper part of the combustion chamber is communicated with a secondary combustion chamber; a pyrolysis gas nozzle is arranged at the upper part of the combustion chamber; a drying pyrolysis chamber outlet flue with an induced draft fan is arranged close to the upper end of the drying pyrolysis chamber, and the drying pyrolysis chamber outlet flue is connected to a pyrolysis gas nozzle through a condenser; a drainage chamber is arranged between the same side of the combustion chamber and the secondary combustion chamber and the drying pyrolysis chamber, and the drying pyrolysis chamber is longitudinally provided with a smoke nozzle communicated with the drainage chamber. A secondary combustion chamber outlet flue and a circulating flue are arranged at the top of the secondary combustion chamber, the circulating flue is communicated with the drainage chamber, and a guide plate for adjusting the flue gas amount is arranged in the top of the secondary combustion chamber. According to the method, the water content of the garbage entering the incinerator can be reduced, the heat value of the garbage can be increased, the temperature of 850 DEG C / 2 s can be met without afterburning in the incinerator, meanwhile, the garbage can be homogenized before entering the incinerator, and it is guaranteed that the temperature and load fluctuation of the incinerator is small, garbage combustion is sufficient, and the ignition loss of slag is low.

Description

Technical Field

[0001] The present invention relates to the technical field of waste incinerators, and in particular to a small-sized domestic waste incinerator and a use method thereof. Background Art

[0002] At present, domestic domestic waste incineration projects are mainly based on large-scale waste incinerators, and the technology is relatively mature. For remote areas and island-type areas, the population is small and scattered, the garbage output is small, and the garbage transportation cost is high, so it is difficult to carry out centralized large-scale garbage incineration. The decentralized and small-scale on-site disposal of garbage in rural areas, towns, islands and other regions is the main direction of future development. Therefore, there is a strong demand for small-scale domestic waste incinerator technology.

[0003] The main problems of small-scale domestic waste incinerator technology are as follows:

[0004] (1) Domestic waste has a high moisture content and low calorific value, which results in incomplete combustion and requires a large amount of additional fuel.

[0005] The moisture content of domestic garbage is generally more than 50%, and the calorific value is low. If garbage with a large amount of moisture is directly put into the incinerator for incineration, the combustion temperature is low, the garbage is not fully burned, and the thermal loss rate of the garbage is high. At the same time, in order to ensure the furnace temperature of 850℃ / 2s, a large amount of fuel needs to be added, which is costly.

[0006] (2) The amount of domestic waste treated is small, the composition fluctuates greatly, and operation is difficult.

[0007] The scale of garbage treatment is small and the composition fluctuates greatly, which has a great impact on the operation of incinerators and system equipment and is difficult to adjust.

[0008] (3) The concentration of flue gas pollutants is high, making it difficult to meet emission standards.

[0009] Since the burning temperature of garbage is low and the concentration of original pollutants is high, many small-scale garbage incineration projects do not have online flue gas detection devices. If the flue gas emission is to meet the standard, the operating cost is high.

[0010] (4) The flue gas volume is small and the waste heat of the flue gas cannot be utilized.

[0011] Small-scale waste incineration projects have a small amount of flue gas and the waste heat of the flue gas cannot be used. Most of them use rapid cooling to directly condense the flue gas, which wastes a lot of heat on the one hand and causes a high moisture content in the flue gas on the other hand, which is easy to condense and stick to the bags.

[0012] (5) The incinerator equipment is large, complex in structure, occupies a large area and has a high cost.

[0013] The existing small-scale garbage incinerator still adopts the structure of large-scale incinerator, including drying section, combustion section and burning section, and the grate group consists of sliding grate, flipping grate and fixed grate. Small-scale incinerator equipment is large, occupies a large area, and has a complex structure and high cost.

[0014] Patent CN 118189179 B discloses a pyrolysis and gasification small-scale domestic waste incinerator and its disposal process. A pyrolysis chamber is set at the front end of the incinerator. By controlling the pressure distribution of the combustion chamber, the hot flue gas generated by combustion is passed into the bottom of the pyrolysis chamber to dry, pyrolyze and gasify the garbage. This method can reduce the moisture content of the garbage and increase the calorific value of the garbage entering the furnace. However, in this method, it is difficult to control the amount of hot flue gas entering the pyrolysis chamber, and it is difficult to make the hot flue gas enter the pyrolysis chamber evenly. The dryness of the garbage in the pyrolysis chamber is difficult to control; the moisture generated by the drying of the garbage is still in the flue gas, and the moisture content in the flue gas is high, which is easy to condense and stick to the bag; the pyrolysis chamber is directly connected to the combustion chamber, the temperature at the bottom of the pyrolysis chamber is high, and there is a lot of air, the garbage is easy to burn, and the reaction and temperature in the pyrolysis chamber are difficult to control.

[0015] Patent CN 108980847 B discloses a garbage carbonization combustion treatment process, in which a drying layer and a carbonization layer are arranged at the front end of the incinerator, and the garbage is dried and carbonized by using hot flue gas and heat radiation from the furnace. This method can reduce the moisture content of garbage, increase the calorific value of garbage, and condense and remove the moisture in the flue gas. However, the drying grate and the carbonization grate of this method have complex structures, especially the carbonization grate has a high temperature and is easy to be damaged; the carbonization layer is directly connected to the combustion chamber, the carbonization layer has a high temperature, and there is a large amount of air, the garbage is easy to burn, and the reaction and temperature in the drying and carbonization chamber are difficult to control; the hot flue gas rises to a limited height, and it is difficult to control the flow rate and rising area of ​​the hot flue gas; the garbage in the drying layer is mainly dried by radiation heat, and the drying efficiency is low.

[0016] Patent CN 220852160 U discloses a garbage incinerator, in which a pyrolysis chamber is arranged above the incineration chamber, and the radiant heat from the furnace is used to dry and pyrolyze the garbage. This method relies solely on radiant heat to dry the garbage, and the drying efficiency is low; it is difficult to effectively control the drying rate, and the operation is difficult to adjust for changes in the moisture content, calorific value, and composition of the garbage; the pyrolysis chamber is arranged horizontally, and the garbage is difficult to flow, and the use of spiral equipment is prone to blockage.

[0017] In summary, most of the existing small-scale domestic waste incinerators adopt the structure and process of large-scale domestic waste incinerators, and there are problems such as insufficient combustion, unstable operation, substandard flue gas emissions, no utilization of flue gas waste heat, high investment and operation costs. A few small-scale domestic waste incinerators add a drying pyrolysis chamber at the front end of the combustion chamber, which can reduce the moisture content of the garbage entering the furnace, increase the calorific value of the garbage, and contribute to the stable combustion of the garbage. However, the existing drying pyrolysis chamber has a complex structure, difficult operation, low drying efficiency, and is difficult to adjust the working conditions. Moreover, the direct connection between the drying pyrolysis chamber and the combustion chamber can easily lead to combustion and overheating of the drying pyrolysis chamber. Therefore, it is necessary to develop a new type of small-scale domestic waste incinerator, especially a control method suitable for small-scale domestic waste incinerators, so as to adapt to domestic waste with small processing volume, high moisture content, low calorific value, and large composition fluctuations. Summary of the invention

[0018] The purpose of the present invention is to solve the problems of small-scale domestic waste incinerators, such as incomplete waste combustion, low combustion temperature, need to add a large amount of fuel, and excessive emission of flue gas pollutants, due to high water content, low calorific value, and large fluctuation of components. Therefore, it is necessary to develop a small-scale waste incinerator suitable for treating waste with high water content, low calorific value, and large fluctuation of components, and a control method thereof.

[0019] In order to achieve the above object, the present invention adopts the following technical solutions:

[0020] A small-scale domestic waste incinerator comprises a drying pyrolysis chamber and a combustion chamber arranged on a grate group of the waste incinerator, wherein the drying pyrolysis chamber is located at an upstream area of ​​the grate group, and the combustion chamber is located at a downstream area of ​​the grate group;

[0021] The drying pyrolysis chamber is vertical, with a garbage inlet at the top and a garbage outlet at the bottom. The garbage outlet of the drying pyrolysis chamber is covered at one grate group;

[0022] The combustion chamber is covered with the grate group, the upper part of the combustion chamber is connected with a second combustion chamber, and a pyrolysis gas nozzle is arranged on the side wall at the upper part of the combustion chamber;

[0023] A drying pyrolysis chamber outlet flue with an induced draft fan is provided on the side wall of the drying pyrolysis chamber near the upper end, and the drying pyrolysis chamber outlet flue is connected to the pyrolysis gas nozzle through a condenser;

[0024] A drainage chamber is provided between the same side of the combustion chamber and the secondary combustion chamber and the side of the drying pyrolysis chamber. The drainage chamber is lower than the circulating flue of the secondary combustion chamber. The bottom of the drainage chamber is closed and the top is a smoke inlet. A plurality of smoke nozzles are provided along the longitudinal direction of the side of the drying pyrolysis chamber, and the smoke nozzles are connected to the drainage chamber.

[0025] A secondary combustion chamber outlet flue and a circulating flue are respectively arranged on both sides of the secondary combustion chamber top. The circulating flue is connected to the smoke inlet of the drainage chamber. A guide plate for adjusting the amount of smoke flowing into the secondary combustion chamber outlet flue and the circulating flue is arranged inside the secondary combustion chamber top.

[0026] As a further preferred embodiment, the diameters of the plurality of smoke nozzles increase sequentially from top to bottom.

[0027] As a further preferred solution, three sealing gates are provided at the garbage inlet of the drying pyrolysis chamber, and a material-diverting plate is provided at the garbage outlet.

[0028] As a further preferred solution, the grate group consists of sliding grates and fixed grates, and the sliding grates and the fixed grates are arranged alternately.

[0029] As a further preferred solution, the garbage outlet of the drying pyrolysis chamber is sealed by the first-stage sliding grate of the grate group, and the sliding grate also serves as a feeding grate.

[0030] A method for using a small-sized domestic waste incinerator comprises the following steps:

[0031] Step 1: After the garbage is sorted and crushed, it is added to the drying pyrolysis chamber by the bucket elevator;

[0032] Step 2: The high-temperature flue gas generated by the combustion in the secondary combustion chamber is introduced from the flue gas nozzles on the side wall of the drying pyrolysis chamber to dry the garbage in the pyrolysis chamber. Under the heating of the high-temperature flue gas, drying and pyrolysis reactions occur. The generated water vapor and a small amount of combustible gas enter the high-temperature flue gas and are discharged from the flue at the outlet of the drying pyrolysis chamber.

[0033] Step 3: The dried garbage falls from the garbage outlet onto the grate group. With the push of the sliding grate in the grate group, the garbage moves downstream. When passing through the fixed grate in the grate group, the garbage is turned over. The bottom ash produced by the combustion of the garbage is discharged from the slag outlet of the grate group, and the smoke produced by the combustion enters the combustion chamber.

[0034] Step 4: The combustion chamber is supplemented with primary air through the bottom of the grate group, and secondary air is supplemented through the opening of the rear arch of the furnace. Under the action of the secondary air, the flue gas is fully mixed to ensure complete combustion;

[0035] Step 5: Dry the flue gas generated in the pyrolysis chamber. After condensation in the condenser, the dry flue gas is added to the combustion chamber from the pyrolysis gas nozzle to completely burn a small amount of combustible gas. The condensed water generated by the condenser can be used as water for the quench tower.

[0036] Step 6: The flue gas generated in the combustion chamber enters the secondary combustion chamber, ensuring that the flue gas temperature is above 850°C and the flue gas residence time exceeds 2s. The flue gas generated in the secondary combustion chamber is divided through the guide plate, with one part entering the drainage chamber and the other part being discharged from the secondary combustion chamber outlet flue;

[0037] Step 7: After the high-temperature flue gas enters the drainage chamber, it passes through several layers of flue gas nozzles in sequence and enters positions at different heights in the drying pyrolysis chamber.

[0038] As a further preferred embodiment, in step one, the three sealing gates at the garbage entrance of the drying pyrolysis chamber are first opened when adding materials, the garbage is poured in, the first sealing gate is closed, the second sealing gate is opened, and finally the second sealing gate is closed and the third sealing gate is opened, and the garbage enters the drying pyrolysis chamber.

[0039] As a further preferred solution, in step three, the dried garbage is discharged from the garbage outlet to the grate group, and the material transfer plate is rotated to flip the garbage up and down to make it fall smoothly.

[0040] As a further preferred solution, in step six, the amount of flue gas entering the drainage chamber and the secondary combustion chamber outlet flue is adjusted by adjusting the installation position of the guide plate, and the adjustment process is as follows:

[0041] Assume that the element composition of the garbage entering the drying pyrolysis chamber is C ar , H ar , O ar 、N ar , S ar , water content is M ar ;

[0042] The mass, moisture content, calorific value and temperature of the garbage entering the drying pyrolysis chamber are m1, w1, Q1 and t1 respectively;

[0043] The mass, moisture content, calorific value and temperature of the waste discharged from the drying pyrolysis chamber are m2, w2, Q2 and t2 respectively;

[0044] The flue gas temperature entering the drying pyrolysis chamber from the flue gas nozzle is t3, and the flue gas temperature entering the drying pyrolysis chamber outlet flue from the drying pyrolysis chamber is t4;

[0045] The specific heat capacities of garbage, water, water vapor, and high-temperature flue gas are c1, c2, c3, and c4 respectively;

[0046] The excess air coefficient in the incinerator is α;

[0047] The latent heat of vaporization of water is q;

[0048] The pressures at the secondary combustion chamber, the drainage chamber, and the secondary combustion chamber outlet flue are P, P1, and P2 respectively;

[0049] The distances between the guide plate and the flue opening leading to the draft chamber and the flue opening leading to the secondary combustion chamber outlet are L1 and L2 respectively;

[0050] The flue gas volumes from the secondary combustion chamber to the drainage chamber and the secondary combustion chamber outlet flue are V1 and V2 respectively.

[0051] Then: The heat required for drying the pyrolysis chamber is:

[0052] H1=(m1-m2)q+c1m1(1-w1)(t2-t1)+c2m1w1(100-t1)+c3(m1-m2)(t4-100)

[0053] The amount of high-temperature flue gas that needs to be introduced into the drying pyrolysis chamber is:

[0054]

[0055] The amount of flue gas produced by combustion in the second combustion chamber is:

[0056] V y =m1[(1×10 -6 +0.0903α)C ar +(7×10 -6 +0.0338α)S ar +(0.05535+0.2693α)H ar +(0.006993-0.0338α)O ar +0.008N ar +0.0124M ar Formula (2)

[0057] By adjusting the position of the guide plate and the power of the induced draft fan, the following equation is established;

[0058]

[0059] Substituting equations (1) and (2) into equation (3), we can obtain a control method for a small-scale domestic waste incinerator; by adjusting the position of the guide plate to change L1 and L2, and by adjusting the power of the induced draft fan to change P1 and P2, we can finally make equation (3) true, so that the amount of high-temperature flue gas entering the drying pyrolysis chamber can meet the heat required to reduce the moisture content of the waste from w1 to w2.

[0060] Beneficial Effects

[0061] (1) The moisture content of domestic garbage is generally more than 50%, and the calorific value is low. If garbage with a large amount of moisture is directly put into the incinerator for incineration, the combustion temperature is low, the garbage is not fully burned, and the thermal loss rate of the garbage is high. At the same time, in order to ensure the furnace temperature of 850℃ / 2s, a large amount of fuel needs to be added, which is costly.

[0062] This patent develops a small-scale domestic waste incinerator, including a drying pyrolysis chamber, a grate group, a combustion chamber, a secondary combustion chamber, a drainage chamber, an induced draft fan, and a condenser. After sorting and crushing, the domestic waste is added to the drying pyrolysis chamber, and the domestic waste is dried and pyrolyzed by the high-temperature flue gas introduced from the secondary combustion chamber. The water vapor and a small amount of combustible gas generated by the drying pyrolysis are condensed and passed into the combustion chamber. The dried waste is fully burned in the combustion chamber through the grate group, and then enters the secondary combustion chamber to ensure 850℃ / 2s.

[0063] This method can reduce the moisture content of the garbage entering the furnace, increase the calorific value of the garbage, and enable the incinerator to meet 850°C / 2s without the need for supplementary burning. At the same time, the garbage burns more completely and the thermal loss rate is low.

[0064] (2) In existing small-scale domestic waste incinerators, the drying pyrolysis chamber is directly connected to the combustion chamber. The temperature at the bottom of the drying pyrolysis chamber is relatively high, and the air supplied from the combustion chamber also enters the drying pyrolysis chamber. Therefore, the garbage at the bottom of the drying pyrolysis chamber is easily burned. The temperature inside the drying pyrolysis chamber is relatively high, which causes great damage to the equipment. At the same time, once the drying pyrolysis chamber burns, it is easy for the material to collapse and the airflow to cross flow, and a large amount of high-temperature unburned smoke will escape from the top of the drying pyrolysis chamber, posing a great safety risk.

[0065] This patent separates the drying pyrolysis chamber from the combustion chamber by a feeding grate group, which prevents the gas in the combustion chamber from entering the drying pyrolysis chamber, and can ensure an oxygen-deficient atmosphere in the drying pyrolysis chamber, so that problems such as excessive temperature, material collapse, unburned smoke emission, and coking resulting in poor material feeding caused by combustion will not occur.

[0066] (3) Some drying pyrolysis chambers only use the radiant heat from the furnace to dry the garbage, which results in low drying efficiency. Although some use hot flue gas to dry the garbage, the hot flue gas is unevenly distributed, and it is difficult to effectively control the amount and distribution of the hot flue gas, resulting in poor drying degree and uniformity of the garbage.

[0067] This patent sets a drainage chamber at the outlet of the secondary combustion chamber, and passes the high-temperature flue gas generated by the secondary combustion chamber into the drying pyrolysis chamber after passing through the drainage chamber, and uses the high-temperature flue gas to directly contact the garbage to dry the garbage, which has higher drying efficiency. On the wall surface connecting the drainage chamber and the drying pyrolysis chamber, there are layers of flue gas nozzles of different sizes from top to bottom. By changing the size of the flue gas nozzle, the amount of flue gas entering different positions of the drying pyrolysis chamber 1 is controlled, and the drying uniformity is better.

[0068] (4) The existing drying pyrolysis chamber has a complex structure, with many internal components and equipment, which is easy to be blocked and difficult to unload. In addition, the temperature inside the drying pyrolysis chamber is high, the internal components and equipment are easily damaged, and the cost is also high.

[0069] The patented drying pyrolysis chamber has a simple structure, without many internal components and equipment, and only a material-dispensing device is installed at the bottom. The garbage in the drying pyrolysis chamber is loosened by the rotation of the material-dispensing device, and the garbage is smoothly discharged. The top is sealed by a sealing gate to ensure the airtightness of the drying pyrolysis chamber. The device has a simple structure, low cost and low failure rate.

[0070] (5) The flue gas dried in the existing drying pyrolysis chamber is directly introduced into the combustion chamber or the secondary combustion chamber for combustion. A large amount of moisture generated by garbage drying enters the flue gas again, resulting in a high moisture content in the flue gas and lowering the flue gas temperature.

[0071] This patent condenses the flue gas generated by the drying pyrolysis chamber, removes the moisture, and then passes the flue gas into the combustion chamber and the secondary combustion chamber. This method can reduce the moisture content in the flue gas and avoid condensation and bag sticking. At the same time, it can reduce the amount of flue gas entering the secondary combustion chamber and increase the temperature of the secondary combustion chamber. The condensed water can be used as a supplement to the rear-end quenching tower to reduce water consumption.

[0072] (6) The drying process in the existing drying pyrolysis chamber is difficult to control. The amount of flue gas entering the drying pyrolysis chamber cannot be effectively controlled, and the position and distribution of the flue gas entering the drying pyrolysis chamber cannot be adjusted. In the case of fluctuations in moisture and composition, the drying pyrolysis chamber and incinerator cannot be effectively, quantitatively, and accurately controlled.

[0073] This patent develops a control method that matches a small-scale domestic waste incinerator. By changing the position of the guide plate in the secondary combustion chamber and the fan power, the amount of flue gas entering the drying pyrolysis chamber can be controlled. When the moisture and composition of the garbage changes, the amount of flue gas entering the drying pyrolysis chamber can be adjusted in a timely, effective and accurate manner by quantitatively changing the position of the guide plate and the fan power, thereby converting complex and changeable garbage into garbage with stable calorific value, thereby ensuring the stable operation of the incinerator and the entire device. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0075] In the figure: 1: drying pyrolysis chamber; 2: grate group; 3: combustion chamber; 4: secondary combustion chamber; 5: secondary combustion chamber outlet flue; 6: draft chamber; 7: induced draft fan; 8: condenser; 9: pyrolysis gas nozzle; 10: sealing gate; 11: material shifting plate; 12: flue gas nozzle; 13: guide plate; 14: drying pyrolysis chamber outlet flue. DETAILED DESCRIPTION

[0076] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0077] This patent develops a small-scale domestic waste incinerator, mainly for domestic waste incinerators with a scale of less than 50 tons / day. The incinerator includes a drying pyrolysis chamber 1, a grate group 2, a combustion chamber 3, a secondary combustion chamber 4, a drainage chamber 6, an induced draft fan 7, and a condenser 8. A drying pyrolysis chamber 1 is added in front of the combustion chamber 3, and the domestic waste is added to the drying pyrolysis chamber 1 after sorting and crushing. The high-temperature flue gas introduced from the secondary combustion chamber 4 is passed into the drying pyrolysis chamber 1 through the drainage chamber 6 to dry and pyrolyze the domestic waste.

[0078] After drying, the moisture content of the garbage is reduced, the calorific value is increased, and the composition is relatively stable. It can be stably burned in the combustion chamber 3, and the secondary combustion chamber 4 does not need to be supplemented, which can meet the requirements of 850℃ / 2s, and the concentration of flue gas pollutants is low. At the same time, a new control method for small-scale domestic waste incinerators has been developed. Through the design of the secondary combustion chamber 4 and the drainage chamber 6 structure, as well as the adjustment of process parameters, it can adapt to garbage with different moisture content, calorific value and composition.

[0079] Specifically, the water vapor and a small amount of combustible gas generated by the drying pyrolysis are condensed and passed into the combustion chamber 3. The dried garbage is fully burned in the combustion chamber 3 through the grate group 2, and then enters the secondary combustion chamber 4 to ensure 850℃ / 2s. A part of the flue gas generated in the secondary combustion chamber 4 is passed into the drying pyrolysis chamber 1 after passing through the drainage chamber 6, and the other part is discharged from the secondary combustion chamber outlet flue 5.

[0080] This patent separates the drying pyrolysis chamber 1 and the combustion chamber 3 by the feeding grate group 2, and does not directly connect them, so as to prevent the gas in the combustion chamber 3 from entering the drying pyrolysis chamber 1, and can ensure an oxygen-deficient atmosphere in the drying pyrolysis chamber 1, so as to prevent problems such as excessive temperature, material collapse, unburned smoke emission, and coking resulting in poor material feeding caused by combustion.

[0081] This patent sets a drainage chamber 6 at the outlet of the secondary combustion chamber 4, and the high-temperature flue gas generated by the secondary combustion chamber 4 is passed into the drying pyrolysis chamber 1 after passing through the drainage chamber 6. The garbage is dried by direct contact between the high-temperature flue gas and the garbage, which has a higher drying efficiency. At the same time, the hot flue gas can be quantitatively and controlledly introduced into the drying pyrolysis chamber 1.

[0082] On the wall connecting the drainage chamber 6 and the drying pyrolysis chamber 1, there are three layers of flue gas nozzles 12 of different sizes from top to bottom. By changing the size of the flue gas nozzles 12, the amount of flue gas entering different positions of the drying pyrolysis chamber 1 is controlled, so that the hot flue gas can evenly enter different positions of the garbage material layer, ensuring the uniformity of the entire drying pyrolysis chamber 1.

[0083] The drying pyrolysis chamber 1 of the present invention has a simple structure, and does not have many internal components and equipment. Only a material-dispensing device is installed at the bottom. The garbage in the drying pyrolysis chamber 1 is loosened by the rotation of the material-dispensing device, and the garbage is smoothly discharged. The top is sealed by a sealing gate 10 to ensure the airtightness of the drying pyrolysis chamber 1. The device has a simple structure, low cost, and low failure rate.

[0084] In this patent, the flue gas generated by the drying pyrolysis chamber 1 is first condensed to remove the moisture before passing the flue gas into the combustion chamber 3 and the secondary combustion chamber 4. This method can reduce the moisture content in the flue gas and avoid condensation and bag sticking. At the same time, the amount of flue gas entering the secondary combustion chamber 4 can be reduced and the temperature of the secondary combustion chamber 4 can be increased. The condensed water can be used as a supplement to the rear-end quenching tower to reduce water consumption.

[0085] This patent can control the amount of flue gas entering the drying pyrolysis chamber 1 by changing the position of the guide plate 13 in the secondary combustion chamber 4 and the fan power. When the moisture and composition of the garbage change, the amount of flue gas entering the drying pyrolysis chamber 1 can be adjusted in a timely, effective and accurate manner by quantitatively changing the position of the guide plate 13 and the fan power, thereby converting complex and changeable garbage into garbage with stable calorific value, thereby ensuring the stable operation of the incinerator and the entire device.

[0086] The specific process is:

[0087] (1) After being sorted and crushed, the garbage is added to the drying pyrolysis chamber 1 by a bucket elevator. There are three sealing gates 10 on the top of the drying pyrolysis chamber 1. When adding materials, first open the first sealing gate 10 and pour the garbage in. Then close the first sealing gate 10 and open the second sealing gate 10. Finally, close the second sealing gate 10 and open the third sealing gate 10. The airtightness of the drying pyrolysis chamber 1 can be ensured by controlling the sealing gates 10.

[0088] (2) The high-temperature flue gas generated by the combustion in the secondary combustion chamber 4 is introduced from the three-layer flue gas nozzle 12 on the side wall of the drying pyrolysis chamber 1. The garbage in the drying pyrolysis chamber 1 is heated by the high-temperature flue gas to undergo drying and pyrolysis reactions. The generated water vapor and a small amount of combustible gas enter the high-temperature flue gas and are discharged from the drying pyrolysis chamber outlet flue 14. A material-diverting plate 11 is provided at the bottom of the drying pyrolysis chamber 1, which can be flipped up and down to make the garbage fall smoothly.

[0089] (3) The dried garbage falls onto the grate group 2. The grate group 2 consists of a sliding grate and a fixed grate. The garbage moves forward through the sliding grate. When falling through the fixed grate, the garbage is turned over. The bottom slag produced by the combustion of the garbage is discharged from the slag outlet, and the smoke enters the combustion chamber 3.

[0090] (4) The combustion chamber 3 is supplemented with primary air through the grate group 2, and secondary air is supplemented through the rear arch of the furnace. Under the action of the secondary air, the flue gas is fully mixed to ensure complete combustion. The flue gas generated by the dry pyrolysis chamber 1 is condensed by the condenser 8 and added to the combustion chamber 3 from the pyrolysis gas nozzle 9 to completely burn a small amount of combustible gas. The condensed water generated by the condenser 8 can be used as water for the quenching tower.

[0091] (5) The flue gas generated in the combustion chamber 3 enters the secondary combustion chamber 4, ensuring that the flue gas temperature is above 850°C and the flue gas residence time exceeds 2 seconds. The flue gas generated in the secondary combustion chamber 4 passes through the guide plate 13, part of which enters the drainage chamber 6, and part of which is discharged from the secondary combustion chamber outlet flue 5.

[0092] (6) The draft chamber 6 is separated from the secondary combustion chamber 4 by refractory materials. After entering the draft chamber 6, the high-temperature flue gas passes through three layers of flue gas nozzles 12 in sequence and enters different positions of the drying pyrolysis chamber 1.

[0093] Furthermore, the diameter of the three layers of flue gas nozzles 12 increases step by step from top to bottom. By changing the diameter of the flue gas nozzles 12, the amount of high-temperature flue gas entering different positions of the drying pyrolysis chamber 1 is basically the same, so that the garbage in the entire drying pyrolysis chamber 1 can be dried more evenly.

[0094] Furthermore, the position of the guide plate 13 can be moved to adapt to the moisture content of different garbage. The specific control method is as follows.

[0095] Assume that the element composition of the garbage at the entrance of drying pyrolysis chamber 1 is C ar , H ar , O ar 、N ar , S ar , water content is M ar ;

[0096] The mass, moisture content, calorific value and temperature of the garbage at the entrance of the drying pyrolysis chamber 1 are m1, w1, Q1 and t1 respectively;

[0097] The mass, moisture content, calorific value and temperature of the waste at the outlet of drying pyrolysis chamber 1 are m2, w2, Q2 and t2 respectively;

[0098] The inlet and outlet temperatures of the high-temperature flue gas in the drying pyrolysis chamber 1 are t3 and t4 respectively;

[0099] The specific heat capacities of garbage, water, water vapor, and high-temperature flue gas are c1, c2, c3, and c4 respectively;

[0100] The excess air coefficient in the incinerator is α;

[0101] The latent heat of vaporization of water is q;

[0102] The pressures at the secondary combustion chamber 4, the drainage chamber 6, and the secondary combustion chamber outlet flue 5 are P, P1, and P2 respectively;

[0103] The distances between the guide plate 13 and the left and right sides of the secondary combustion chamber 4 are L1 and L2 respectively;

[0104] The flue gas volumes from the secondary combustion chamber 4 to the drainage chamber 6 and the secondary combustion chamber outlet flue 5 are V1 and V2 respectively.

[0105] Then: The heat required for drying pyrolysis chamber 1 is:

[0106] H1=(m1-m2)q+c1m1(1-w1)(t2-t1)+c2m1w1(100-t1)+c3(m1-m2)(t4-100)

[0107] The amount of high-temperature flue gas that needs to be introduced into the drying pyrolysis chamber 1 is:

[0108]

[0109] The amount of flue gas produced by combustion in the second combustion chamber 4 is:

[0110] V y =m1[(1×10 -6 +0.0903α)C ar +(7×10 -6 +0.0338α)S ar +(0.05535+0.2693α)H ar +(0.006993-0.0338α)O ar +0.008N ar +0.0124M ar Formula (2)

[0111] By adjusting the position of the guide plate 13 and the power of the induced draft fan 7, the following equation is established.

[0112]

[0113] Substituting equations (1) and (2) into equation (3), a control method for a small-scale domestic waste incinerator can be obtained. By adjusting the position of the guide plate 13 to change L1 and L2, and by adjusting the power of the induced draft fan 7 to change P1 and P2, equation (3) is finally established, so that the amount of high-temperature flue gas entering the drying pyrolysis chamber 1 satisfies the heat required to reduce the moisture content of the waste from w1 to w2.

[0114] This control method can adapt to the changes in different garbage components. When the moisture content of the garbage changes, the amount of high-temperature flue gas entering the drying pyrolysis chamber 1 is changed by adjusting the position of the guide plate 13 and the power of the induced draft fan 7, and finally the moisture content and calorific value of the garbage entering the grate group 2 are kept constant.

[0115] Through this device and control method, complex and changeable garbage can be converted into garbage with stable moisture content and calorific value, thereby ensuring the stability of combustion in the incinerator. At the same time, the setting of the drying pyrolysis chamber 1 can reduce the moisture content of the garbage and increase the calorific value, thereby increasing the incineration temperature, and can meet 850℃ / 2s without supplementary combustion. This control method can quantitatively control the distribution of high-temperature flue gas generated by the secondary combustion chamber 4, thereby more accurately controlling the calorific value of the dried garbage, and can achieve automatic control.

[0116] Embodiment 1:

[0117] The original waste components are shown in the following table:

[0118] Project Name <![CDATA[C ar ]]> <![CDATA[H ar ]]> <![CDATA[O ar ]]> <![CDATA[N ar ]]> <![CDATA[S ar ]]> <![CDATA[M ar ]]> Value / % 18 2 10 0.7 0.5 60

[0119] The calorific value of raw garbage is 1343kcal / kg.

[0120] It is required to increase the calorific value of the waste entering the furnace to 2000 kcal / kg by drying in the pyrolysis chamber 1. The moisture content of the waste entering the furnace is 46.5%.

[0121] The small-scale domestic waste treatment capacity is 500kg / h, and the original waste temperature is 20℃.

[0122] The temperature of the garbage at the outlet of the drying pyrolysis chamber 1 is 300°C and the mass flow rate is 374kg / h.

[0123] The excess air coefficient of the incinerator is 1.4.

[0124] The inlet temperature and outlet temperature of the high-temperature flue gas in the drying pyrolysis chamber 1 are 1050°C and 200°C respectively.

[0125] Through the control of the induced draft fan 7, the pressures in the secondary combustion chamber 4, the induced draft chamber 6, and the secondary combustion chamber outlet flue 5 are respectively -100 kPa, -300 kPa, and -250 kPa.

[0126] It is necessary to adjust the position of the guide plate 13 so that L1 / L2=0.214.

[0127] By adjusting the position of the guide plate 13 and the power of the induced draft fan 7 according to the above method, the calorific value of the garbage entering the furnace can be set to 2000 kcal / kg.

[0128] Embodiment 2:

[0129] When the original garbage composition changes, as shown in the following table:

[0130] Project Name <![CDATA[C ar ]]> <![CDATA[H ar ]]> <![CDATA[O ar ]]> <![CDATA[N ar ]]> <![CDATA[S ar ]]> <![CDATA[M ar ]]> Value / % 20 2.5 12 1.0 0.7 50

[0131] At this time, the calorific value of the original garbage is 1641kcal / kg.

[0132] It is still required to increase the calorific value of the garbage entering the furnace to 2000 kcal / kg by drying in the pyrolysis chamber 1. The moisture content of the garbage entering the furnace is 42.0%.

[0133] The scale of small domestic waste treatment is still 500kg / h, and the original waste temperature is 20℃.

[0134] The temperature of the garbage at the outlet of the drying pyrolysis chamber 1 is 300°C and the mass flow rate is 431kg / h.

[0135] The excess air coefficient of the incinerator is 1.4.

[0136] The inlet temperature and outlet temperature of the high-temperature flue gas in the drying pyrolysis chamber 1 are 1050°C and 200°C respectively.

[0137] Through the control of the induced draft fan 7, the pressures in the secondary combustion chamber 4, the induced draft chamber 6, and the secondary combustion chamber outlet flue 5 are respectively -100 kPa, -300 kPa, and -250 kPa.

[0138] It is necessary to adjust the position of the guide plate 13 so that L1 / L2=0.154.

[0139] By adjusting the position of the guide plate 13 and the power of the induced draft fan 7 according to the above method, the calorific value of the garbage entering the furnace can be set to 2000 kcal / kg.

[0140] Compared with Example 1, when the moisture content of the original garbage decreases and the calorific value increases, if the pressure in the secondary combustion chamber 4, the drainage chamber 6, and the secondary combustion chamber outlet flue 5 remains unchanged after adjusting the induced draft fan 7, it is necessary to move the guide plate 13 toward the drainage chamber 6 to reduce the amount of flue gas entering the drying pyrolysis chamber 1.

[0141] Embodiment 3:

[0142] When the original garbage composition changes, as shown in the following table:

[0143] Project Name <![CDATA[C ar ]]> <![CDATA[H ar ]]> <![CDATA[O ar ]]> <![CDATA[N ar ]]> <![CDATA[S ar ]]> <![CDATA[M ar ]]> Value / % 22 2.7 13 1.2 0.8 40

[0144] At this time, the calorific value of the original garbage is 1889kcal / kg.

[0145] It is still required to increase the calorific value of the garbage entering the furnace to 2000 kcal / kg by drying in the pyrolysis chamber 1. The moisture content of the garbage entering the furnace is 37.3%.

[0146] The scale of small domestic waste treatment is still 500kg / h, and the original waste temperature is 20℃.

[0147] The temperature of the garbage at the outlet of the drying pyrolysis chamber 1 is 300°C and the mass flow rate is 478kg / h.

[0148] The excess air coefficient of the incinerator is 1.4.

[0149] The inlet temperature and outlet temperature of the high-temperature flue gas in the drying pyrolysis chamber 1 are 1050°C and 200°C respectively.

[0150] Through the control of the induced draft fan 7, the pressures in the secondary combustion chamber 4, the induced draft chamber 6, and the secondary combustion chamber outlet flue 5 are respectively -100 kPa, -300 kPa, and -250 kPa.

[0151] Then it is necessary to adjust the position of the guide plate 13 so that L1 / L2=0.110.

[0152] By adjusting the position of the guide plate 13 and the power of the induced draft fan 7 according to the above method, the calorific value of the garbage entering the furnace can be set to 2000 kcal / kg.

[0153] Compared with Example 2, when the moisture content of the original garbage is further reduced and the calorific value is increased, if the pressure in the secondary combustion chamber 4, the drainage chamber 6, and the secondary combustion chamber outlet flue 5 remains unchanged after adjusting the induced draft fan 7, it is necessary to move the guide plate 13 further toward the drainage chamber 6, so as to reduce the amount of flue gas entering the drying pyrolysis chamber 1.

[0154] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A small-scale domestic waste incinerator, characterized in that: The invention comprises a drying pyrolysis chamber (1) and a combustion chamber (3) arranged on a grate group (2) of a waste incinerator, wherein the drying pyrolysis chamber (1) is located at an upstream position of the grate group (2), and the combustion chamber (3) is located at a downstream region of the grate group (2); The drying pyrolysis chamber (1) is vertical, with a garbage inlet at its upper end and a garbage outlet at its lower end. The garbage outlet of the drying pyrolysis chamber (1) covers one part of the grate group (2); The combustion chamber (3) covers the grate group (2), the upper part of the combustion chamber (3) is connected to the secondary combustion chamber (4), and a pyrolysis gas nozzle (9) is provided on the side wall of the combustion chamber (3) at the upper part; A drying pyrolysis chamber outlet flue (14) with an induced draft fan (7) is provided on the side wall of the drying pyrolysis chamber (1) at the upper end, and the drying pyrolysis chamber outlet flue (14) is connected to the pyrolysis gas nozzle (9) through a condenser (8); A drainage chamber (6) is provided between the same side of the combustion chamber (3) and the secondary combustion chamber (4) and the side of the drying pyrolysis chamber (1); the bottom end of the drainage chamber (6) is closed and the top end is a smoke inlet; a plurality of smoke nozzles (12) are provided along the longitudinal direction of the side of the drying pyrolysis chamber (1); the smoke nozzles (12) are connected to the drainage chamber (6); A secondary combustion chamber outlet flue (5) and a circulating flue are respectively provided on both sides of the top of the secondary combustion chamber (4); the circulating flue is connected to the smoke inlet of the drainage chamber (6); and a guide plate (13) for adjusting the amount of smoke flowing into the secondary combustion chamber outlet flue (5) and the circulating flue is provided in the top of the secondary combustion chamber (4).

2. A small-sized domestic waste incinerator according to claim 1, characterized in that: The calibers of the plurality of smoke nozzles (12) increase sequentially from top to bottom.

3. A small-sized domestic waste incinerator according to claim 2, characterized in that: The garbage inlet of the drying pyrolysis chamber (1) is provided with three sealing gates (10), and the garbage outlet is provided with a material shifting plate (11).

4. A small-sized domestic waste incinerator according to claim 3, characterized in that: The grate group (2) consists of sliding grates and fixed grates, and the sliding grates and the fixed grates are arranged alternately.

5. A small-sized domestic waste incinerator according to claim 4, characterized in that: The garbage outlet of the drying pyrolysis chamber (1) is sealed by the first-stage sliding grate of the grate group (2), and the sliding grate also serves as a feeding grate.

6. The method for using a small-sized domestic waste incinerator according to claim 5, characterized in that: The following steps are involved: Step 1: After the garbage is sorted and crushed, it is added to the drying and pyrolysis chamber (1) by a bucket elevator; Step 2: high-temperature flue gas generated by combustion in the secondary combustion chamber (4) is introduced from a plurality of flue gas nozzles (12) on the side wall of the drying pyrolysis chamber (1), and the garbage in the drying pyrolysis chamber (1) undergoes drying and pyrolysis reactions under the heating of the high-temperature flue gas, and the generated water vapor and a small amount of combustible gas enter the high-temperature flue gas and are discharged from the drying pyrolysis chamber outlet flue (14); Step 3: The dried garbage falls from the garbage outlet onto the grate assembly (2). As the sliding grate in the grate assembly (2) pushes the garbage to move downstream, the garbage is turned over when it falls through the fixed grate in the grate assembly (2). The bottom ash produced by the combustion of the garbage is discharged from the slag outlet of the grate assembly (2), and the smoke produced by the combustion enters the combustion chamber (3); Step 4: The combustion chamber (3) is supplied with primary air through the bottom of the grate group (2), and secondary air is supplied through the opening of the rear arch of the furnace. Under the action of the secondary air, the flue gas is fully mixed to ensure complete combustion; Step 5: Dry the flue gas generated in the pyrolysis chamber (1), and add the dry flue gas condensed by the condenser (8) into the combustion chamber (3) from the pyrolysis gas nozzle (9) to completely burn a small amount of combustible gas. The condensed water generated by the condenser (8) can be used as water for the quench tower; Step 6: The flue gas generated in the combustion chamber (3) enters the secondary combustion chamber (4), ensuring that the flue gas temperature is above 850°C and the flue gas residence time exceeds 2 seconds. The flue gas generated in the secondary combustion chamber (4) is divided through the guide plate (13), with one part entering the drainage chamber (6) and the other part being discharged from the secondary combustion chamber outlet flue (5). Step 7: After the high-temperature flue gas enters the drainage chamber (6), it passes through several layers of flue gas nozzles (12) in sequence and enters positions at different heights of the drying pyrolysis chamber (1).

7. The method for using a small-sized domestic waste incinerator according to claim 6, characterized in that: In the step 1, the three sealing gates (10) at the garbage entrance of the drying pyrolysis chamber (1) are opened first when adding materials, the garbage is poured in, the first sealing gate (10) is closed, the second sealing gate (10) is opened, and finally the second sealing gate (10) is closed again, the third sealing gate (10) is opened, and the garbage enters the drying pyrolysis chamber (1).

8. The method for using a small-sized domestic waste incinerator according to claim 6, characterized in that: In the step three, the dried garbage is discharged from the garbage outlet to the grate group (2), and the material transfer plate (11) is rotated to make the garbage fall smoothly by flipping it up and down.

9. The method for using a small-sized domestic waste incinerator according to claim 6, characterized in that: In step 6, the amount of smoke entering the drainage chamber (6) and the secondary combustion chamber outlet flue (5) is adjusted by adjusting the installation position of the guide plate (13), and the adjustment process is as follows: Assume that the element composition of the garbage entering the drying pyrolysis chamber (1) is C ar , H ar , O ar 、N ar , S ar , water content is M ar ; The mass, moisture content, calorific value and temperature of the garbage entering the drying pyrolysis chamber (1) are m1, w1, Q1 and t1 respectively; The mass, moisture content, calorific value and temperature of the waste discharged from the drying pyrolysis chamber (1) are m2, w2, Q2 and t2 respectively; The temperature of the flue gas entering the drying pyrolysis chamber (1) from the flue gas nozzle (12) is t3, and the temperature of the flue gas entering the drying pyrolysis chamber outlet flue (14) from the drying pyrolysis chamber (1) is t4; The specific heat capacities of garbage, water, water vapor, and high-temperature flue gas are c1, c2, c3, and c4 respectively; The excess air coefficient in the incinerator is α; The latent heat of vaporization of water is q; The pressures at the secondary combustion chamber (4), the drainage chamber (6), and the secondary combustion chamber outlet flue (5) are P, P1, and P2, respectively; The distances between the guide plate (13) and the flue opening leading to the drainage chamber (6) and the flue opening leading to the secondary combustion chamber outlet flue (5) are L1 and L2 respectively; The flue gas volumes from the secondary combustion chamber (4) to the drainage chamber (6) and the secondary combustion chamber outlet flue (5) are V1 and V2 respectively. Then: The heat required for the drying pyrolysis chamber (1) is: H1=(m1-m2)q+c1m1(1-w1)(t2-t1)+c2m1w1(100-t1)+c3(m1-m2)(t4-100) The amount of high-temperature flue gas that needs to be introduced into the drying pyrolysis chamber (1) is: The amount of smoke generated by combustion in the second combustion chamber (4) is: V y = m1[(1×10 -6 + 0.0903α)C ar +(7×10 -6 + 0.0338α)S ar +(0.05535 + 0.2693α)H ar +(0.006993 - 0.0338α)O ar + 0.008N ar + 0.0124M ar Equation (2) By adjusting the position of the guide plate (13) and the power of the induced draft fan (7), the following equation is established: Substituting equations (1) and (2) into equation (3), a control method for a small-scale domestic waste incinerator can be obtained; by adjusting the position of the guide plate (13) to change L1 and L2, and by adjusting the power of the induced draft fan (7) to change P1 and P2, equation (3) is finally established, so that the amount of high-temperature flue gas entering the drying pyrolysis chamber (1) satisfies the heat required to reduce the moisture content of the waste from w1 to w2.

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