Sludge incinerator and its working method

Abstract

This invention relates to a sludge incinerator and its operating method. The sludge incinerator, from bottom to top, comprises an air chamber, a variable diameter section, an ascending section, a quick-drying section, a dust removal section, and a smoke collection section. The air chamber consists of a vertical section and a horizontal section. The vertical section is equipped with an air distribution plate, and the horizontal section is equipped with an ignition burner. The variable diameter section has an ash overflow port, and an ash pool is located between the ash overflow port and the air distribution plate. The ascending section is equipped with an auxiliary burner and a ventilation guide grille. The quick-drying section is equipped with sludge atomizing spray guns and cooling water spray guns. The dust removal section is equipped with a ceramic tube filter. The smoke collection section has a flue gas outlet. The sludge incinerator also includes a temperature and pressure control system. The sludge incinerator of this invention continuously completes the sludge dewatering and combustion process within the same furnace body. Employing a closed furnace structure, the sludge can be directly incinerated without dewatering, shortening the process flow and eliminating the possibility of sludge or odor overflow during the operation of the sludge treatment system.

Description

Technical Field

[0001] This invention relates to the field of sludge treatment technology, and in particular to a sludge incinerator and its operating method. Background Technology

[0002] Sludge incineration is a sludge treatment process that uses an incinerator to heat and dry dewatered sludge, and then uses high-temperature oxidation to oxidize the organic matter in the sludge, turning the sludge into a small amount of ash. Therefore, it is a method of reducing volume, stabilizing and rendering harmless, which can completely remove moisture and organic matter from the sludge and kill pathogens.

[0003] The currently widely used process route is as follows: first, mechanical sludge dewatering equipment (such as centrifugal dewatering machines, plate and frame filter presses, belt presses, etc.) is used to dewater the sludge; then, sludge drying equipment (such as drum dryers, paddle dryers, disc dryers, fluidized beds, etc.) is used to perform low-temperature thermal drying of the dewatered sludge; finally, the dehydrated sludge is sent to an incinerator for incineration. However, the above process route has the following drawbacks: the process flow is long, and open interfaces between the main equipment and various auxiliary equipment are unavoidable. At these open interfaces, sludge leakage or odor emission can occur, causing severe odor in the air near the process system, resulting in a deterioration of the working environment or directly affecting the lives of nearby residents. For example, plate and frame filter presses must be operated with open openings during chemical dosing and sludge discharge, causing the sludge cake to come into contact with the atmosphere, resulting in a harsh operating environment near the equipment and easy odor overflow. For example, conventional spray drying equipment requires external equipment such as a three-stage dust collector and a rotary kiln. During the material handling process, material spillage or odor leakage is very likely to occur at parts such as the scraper conveyor, air duct expansion joint, feeding port, and dust collector. Summary of the Invention

[0004] This invention provides a sludge incinerator and its operating method, which continuously completes the sludge dewatering and combustion process in the same furnace body. It adopts a closed furnace body structure, and the sludge can be directly incinerated without dewatering, which shortens the process flow and eliminates the possibility of sludge or odor overflow during the operation of the sludge treatment system.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A sludge incinerator comprises, from bottom to top, an air chamber, a variable diameter section, an ascending section, a quick-drying section, a dust removal section, and a smoke collection section. The air chamber consists of a vertical section and a horizontal section. The top of the vertical section is connected to the variable diameter section, and an air distribution plate is located in the middle of the vertical section. An ignition burner is located in the horizontal section. The variable diameter section is a conical cylindrical structure with a smaller bottom opening and a larger top opening. An ash overflow port is located on one side of the lower part of the variable diameter section, and the space between the ash overflow port and the air distribution plate is an ash pool. The ascending section, quick-drying section, and dust removal section are cylindrical structures with the same diameter. An auxiliary burner is located at the lower part of the ascending section, and a ventilation guide grille is located at the upper part. A sludge atomizing spray gun and a cooling water spray gun are located in the middle of the quick-drying section, and the sludge atomizing spray gun and the cooling water spray gun are arranged alternately along the circumference. Multiple filters are installed; the dust removal section is equipped with a ceramic tube filter; the smoke collection section has a dome structure with a flue gas outlet in the center; the sludge incinerator is also equipped with a temperature and pressure control system; the temperature and pressure control system includes a control system, an inlet thermometer, a furnace thermometer, an outlet thermometer, and a pressure sensor, wherein the inlet thermometer is installed on the side wall of the variable diameter section on one side of the ash and slag pool; the furnace thermometer is installed on the side wall of the furnace body in the furnace; the outlet thermometer is installed on the flue gas outlet pipe; the pressure sensor is installed on the side wall of the furnace body above the quick-drying section; the inlet thermometer, furnace thermometer, outlet thermometer, and pressure sensor are respectively connected to the control system, and the control system is also connected to the control terminals of the ignition burner, auxiliary burner, sludge atomizing spray gun, and cooling water spray gun.

[0007] The cross-section of the air chamber is square; the bottom surface of the horizontal section below the vertical section is inclined; the air distribution plate consists of a perforated plate and air caps; multiple air cap insertion holes are opened on the perforated plate, and the air caps are fixed in the corresponding air cap insertion holes; the air cap consists of a cap top and a cap neck, and multiple small holes of 6-8 mm are opened along the circumference of the cap neck. The ratio of the total area of ​​the small holes to the top area of ​​the perforated plate, i.e., the air cap opening rate, is 2.2%-2.8%; the hole spacing of the air cap insertion holes is 1.3-1.7 times the diameter of the air cap, and the minimum distance between the brims of each air cap is greater than 20 mm; every 1.3-1.5 m on the air distribution plate... 2 One ash discharge hole shall be opened within the area.

[0008] The variable diameter section is a conical structure with a round top and a square bottom. The angle between the furnace wall of the variable diameter section and the horizontal plane is not less than 60°. The inner side of the furnace wall of the variable diameter section is provided with a heat insulation layer, and the ash overflow port is located at a height of 0.5 to 1.5m from the bottom surface of the variable diameter section.

[0009] The inner side of the furnace wall in the rising section is provided with a heat insulation layer; there are 8 auxiliary burners, evenly distributed along the circumference; there are 8 furnace thermometers, which are set one by one with the auxiliary burners below; the ventilation guide grille is composed of multiple ventilation beams arranged in a crisscross pattern.

[0010] The inner side of the furnace wall of the quick-drying section is provided with a heat insulation layer; there are 4 sets of sludge atomizing spray guns and 4 sets of cooling water spray guns; the vertical spray opening angle of the sludge atomizing spray gun and the cooling water spray gun is 45° and the horizontal spray opening angle is 135°.

[0011] The inner wall of the dust removal section is equipped with a heat insulation layer; the ceramic tube filter is equipped with a compressed air backflushing and dust removal device.

[0012] A method for operating a sludge incinerator includes the following processes:

[0013] 1) After the ignition burner is ignited and burned, it heats the air to above 850°C. The hot flue gas is evenly distributed into the furnace through the air distribution plate. The temperature inside the incinerator is kept uniform through multiple auxiliary burners set at the bottom of the furnace.

[0014] 2) The sludge is sprayed into the furnace in the middle of the quick-drying section through a sludge atomizing spray gun. It comes into contact with the hot flue gas introduced from the rising section for heat exchange and is instantly dehydrated into sludge dry powder with a particle size of 60-120 mesh and a moisture content of 20%-25%. The sludge dry powder comes into contact with the low-velocity hot flue gas to achieve suspension combustion and is burned off as it falls into the rising section and the diameter changing section. The denser burnt ash and unburned particles fall into the ash and slag pool for final combustion.

[0015] 3) Water vapor released from the sludge flows upward with the hot flue gas. The dried fine sludge particles are carried by the rising hot flue gas to the dust removal section. After being intercepted by the ceramic tube filter, they combine with ash and gradually agglomerate and grow larger. Finally, they are blown back into the furnace during the backflushing cleaning until they are burned out. The clean flue gas after dust removal in the dust removal section carries a large amount of water vapor and is discharged from the sludge incinerator from the smoke collection section.

[0016] The inlet wind speed of the wind chamber shall not exceed 10 m / s; the wind speed at the small hole on the neck of the wind cap on the wind distribution plate shall be 35 to 45 m / s; the hot flue gas velocity in the rising section shall be less than 1 m / s; the hot flue gas temperature at the outlet of the rising section shall not be less than 850℃; the furnace pressure shall be maintained at -90 to -110 Pa; and the target flue gas temperature at the outlet of the smoke collection section shall be 120℃.

[0017] Temperature is measured by an outlet thermometer. When the outlet flue gas temperature is below 120°C, the auxiliary burner is turned on for auxiliary heating. When the outlet flue gas temperature is above 120°C, the output temperature of the ignition burner is reduced or the auxiliary burner is turned off. If the outlet flue gas temperature continues to rise, the sludge injection rate is increased. If the outlet flue gas temperature still rises and reaches 180°C after taking the above measures, emergency cooling water is injected through a cooling water spray gun to cool it down.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1) The sludge incinerator described in this invention helps to shorten the sludge treatment process, reduce the number of equipment, and lower the equipment failure rate.

[0020] 2) The sludge incinerator described in this invention integrates sludge drying and incineration, and the equipment occupies a small area (for example, a sludge incinerator with a daily sludge processing capacity of 300 tons / day occupies only 800m²). 2 It is highly adaptable to fluctuations in the inflow and outflow of upstream and downstream materials.

[0021] 3) The sludge incinerator described in this invention has good sealing performance, which eliminates the odor overflow that is prone to occur during the sludge treatment process and has little impact on the environment.

[0022] 4) The sludge incinerator described in this invention has high incineration efficiency; the ash is boiled and burned in the ash pool before being discharged, the char is burned off, the heat loss of the ash is small, and only one ash overflow port is needed to discharge the ash outside the furnace.

[0023] 5) The sludge incinerator described in this invention produces virtually no fly ash after incinerating sludge, eliminating the need for a bag filter, resulting in extremely low fly ash treatment costs and low operating costs.

[0024] 6) The sludge incinerator described in this invention is environmentally friendly, employing a low-temperature suspension incineration method, resulting in nitrogen oxide emissions of less than 200 mg / m³. 3 No chemical pretreatment process is required for the sludge. Without adding Cl, the native dioxins in the sludge can be decomposed by sludge in a suspended incineration state for more than 2 seconds. The sludge drying process is equivalent to a rapid cooling process, with no dioxin regeneration temperature range and no dioxin pollution. Adding CaO into the furnace can achieve in-furnace desulfurization.

[0025] 7) The sludge incinerator described in this invention uses a sludge atomizing spray gun. The droplets after sludge atomization are very small, and the dried sludge particles are extremely small. The combustion of sludge is mainly completed in the rising section and the diameter changing section. Only the residual carbon is burned in the ash and slag pool, and the heat release is low. Therefore, there is no need to install buried pipe cooling equipment in the ash and slag pool. Instead, an ignition burner is needed to provide temperature support.

[0026] 8) The sludge incinerator of the present invention is equipped with multiple auxiliary burners and ventilation and cooling grids in the high-temperature zone of the rising section, which can obtain a stable flue gas flow field and temperature field, ensuring that the sludge is dried more evenly, the drying effect is better, and the combustion process is more stable.

[0027] 9) The sludge incinerator described in this invention has good operational safety. The upper part of the furnace is cooled by sludge spraying (which can be further cooled by water spraying), and the open flame combustion in the rising section and the diameter changing section can prevent dust explosion.

[0028] 9) The sludge incinerator described in this invention has a simple structure, low maintenance costs, long service life, simple operation, and low operating costs; the sludge atomizing spray gun adopts a horizontal spraying method, eliminating the need to consider the spraying angle, making it easy for workers to operate, with short maintenance and replacement times and low costs; the sludge incinerator has a low combustion temperature, a long operating time in the insulated furnace, and low maintenance costs; the dust removal section uses ceramic filters as dust collectors, which are high-temperature resistant, have a long service life, and low maintenance costs; the incinerator has no pressure components and is a non-pressure vessel, making it easy to operate and inexpensive; sludge pretreatment requires no chemical addition, eliminating chemical costs and investment in chemical dosing equipment.

[0029] 10) The sludge drying operation of the sludge incinerator described in this invention is highly flexible and has lower requirements for the atomizer. It adopts a counter-current drying method for flue gas and sludge, which results in a longer sludge drying time compared to the co-current drying method. Because the hot flue gas and sludge flow in opposite directions, larger sludge particles after atomization will not fall rapidly when they flow downwards due to the lifting effect of the hot flue gas, thus ensuring the combustion effect in the rising section. When the atomized sludge particles are smaller, they will flow upwards with the hot flue gas. Since there is sufficient drying space above, the sludge drying can be successfully ensured. The sludge atomizing spray gun is set at a certain height and is also equipped with a cooling water spray gun to control the temperature and ensure that the temperature field is within a reasonable range.

[0030] 11) Compared with the sludge treatment system of "drying tower + incinerator", the sludge incinerator of the present invention integrates sludge drying and incineration, and does not require conveying equipment between the two, thus saving equipment investment and reducing failure rate.

[0031] 12) This invention uses an incinerator to achieve suspended combustion, which has lower equipment investment costs and a lower failure rate compared with using a rotary kiln as the incineration equipment.

[0032] 13) The multiple auxiliary burners installed in the furnace of the sludge incinerator described in this invention are open flame burners, which create open flame conditions in the large cross-section furnace, have good redundancy, and control the dust concentration in the furnace at 11 g / m³. 3 The following measures ensure that conditions conducive to explosive dust explosions will not be created, resulting in a high level of safety.

[0033] 14) After using the sludge incinerator described in this invention, the water treatment cost after sludge incineration is low, and the water vapor in the flue gas becomes liquid water after condensation, which contains only a small amount of inorganic matter; while the water removed after dewatering sludge using filter press dewatering equipment, indirect drying equipment or circulating air drying dewatering equipment contains difficult-to-treat organic matter. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of a sludge incinerator according to the present invention.

[0035] Figure 2This is a plan view of the sludge spray gun and cooling water spray gun described in this invention.

[0036] Figure 3 This is a plan view of the thermometer arrangement at the outlet of the rising section as described in this invention.

[0037] Figure 4 This is a plan view of the burner layout of the rising section described in this invention.

[0038] Figure 5 This is a plan view of the ventilation beam described in this invention.

[0039] Figure 6 This is a plan view of the pressure sensor arrangement at the outlet of the quick-drying section described in this invention.

[0040] In the diagram: 1. Air chamber 1-1. Vertical section 1-2. Horizontal section 1-3. Air distribution plate 1-4. Ignition burner 2. Variable diameter section 2-1. Ash and slag pool 2-2. Ash and slag overflow port 2-3. Inlet thermometer 3. Rising section 3-1. Auxiliary burner 3-2. Ventilation guide grille 3-3. Furnace thermometer 4. Quick-drying section 4-1. Sludge atomizing spray gun 4-2. Cooling water spray gun 4-3. Pressure sensor 5. Dust removal section 6. Smoke collection section 6-1. Flue gas outlet pipe 6-2. Outlet thermometer 7. Thermal insulation layer Detailed Implementation

[0041] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0042] like Figure 1 As shown, the sludge incinerator of the present invention comprises, from bottom to top, a wind chamber 1, a variable diameter section 2, an ascending section 3, a quick-drying section 4, a dust removal section 5, and a smoke collection section 6. The wind chamber 1 consists of a vertical section 1-1 and a horizontal section 1-2. The top of the vertical section 1-1 is connected to the variable diameter section 2. An air distribution plate 1-3 is provided in the middle of the vertical section 1-1, and an ignition burner 1-4 is provided in the horizontal section 1-2. The variable diameter section 2 is a conical cylindrical structure with a smaller lower opening and a larger upper opening. The lower part of the variable diameter section 2... An ash overflow outlet 2-2 is provided on one side, and the space between the ash overflow outlet 2-2 and the air distribution plate 1-3 is the ash pool 2-1; the rising section 3, the quick-drying section 4, and the dust removal section 5 are cylindrical structures with the same diameter; the lower part of the rising section 3 is provided with an auxiliary burner 3-1, and the upper part is provided with a ventilation guide grille 3-2; the middle part of the quick-drying section 4 is provided with a sludge atomizing spray gun 4-1 and a cooling water spray gun 4-2, and multiple sludge atomizing spray guns 4-1 and cooling water spray guns 4-2 are arranged alternately along the circumference (e.g., Figure 2(As shown); the dust removal section 5 is equipped with a ceramic tube filter; the smoke collection section 6 is a dome structure with a flue gas outlet in the center; the sludge incinerator is also equipped with a temperature and pressure control system; the temperature and pressure control system includes a control system, an inlet thermometer 2-3, a furnace thermometer 3-3, an outlet thermometer 6-2, and a pressure sensor 4-3, wherein the inlet thermometer 2-3 is located on the side wall of the variable diameter section 2 on one side of the ash and slag pool 2-1; the furnace thermometer 3-3 is located on the side wall of the furnace body (as shown); Figure 3 (as shown); outlet thermometer 6-2 is installed on flue gas outlet pipe 6-1; pressure sensor 4-3 is installed on the furnace side wall above the quick-drying section 4 (as shown). Figure 6 (As shown); the inlet thermometer 2-3, furnace thermometer 3-3, outlet thermometer 6-2 and pressure sensor 4-3 are respectively connected to the control system. The control system is also connected to the control terminals of the ignition burner 1-4, auxiliary burner 3-1, sludge atomizing spray gun 4-1 and cooling water spray gun 4-2.

[0043] The cross-section of the air chamber 1 is square; the bottom surface of the horizontal section 1-2 below the vertical section 1-1 is inclined; the air distribution plate 1-3 is composed of a perforated plate and air caps; multiple air cap insertion holes are opened on the perforated plate, and the air caps are fixed in the corresponding air cap insertion holes; the air cap is composed of a cap top and a cap neck, and multiple small holes of 6-8 mm are opened along the circumference of the cap neck. The ratio of the total area of ​​the small holes to the top area of ​​the perforated plate, i.e., the air cap opening rate, is 2.2%-2.8%; the hole spacing of the air cap insertion holes is 1.3-1.7 times the diameter of the air cap, and the minimum distance between the brims of each air cap is greater than 20 mm; every 1.3-1.5 m on the air distribution plate 1-3... 2 One ash discharge hole shall be opened within the area.

[0044] The variable diameter section 2 is a conical structure with a round top and a square bottom. The angle between the furnace wall of the variable diameter section 2 and the horizontal plane is not less than 60°. The inner side of the furnace wall of the variable diameter section 2 is provided with a heat insulation layer 7, and the ash overflow port 2-2 is located at a height of 0.5 to 1.5m from the bottom surface of the variable diameter section 2.

[0045] The inner side of the furnace wall of the rising section 3 is provided with a heat insulation layer 7; there are 8 auxiliary burners 3-1, evenly distributed along the circumference (e.g., Figure 4 (As shown); Furnace thermometers 3-3 consist of 8 units (e.g.) Figure 3 As shown), it is set one-to-one with the auxiliary burner 3-1 below; the ventilation guide grille 3-2 is composed of multiple ventilation beams arranged in a crisscross pattern (as shown). Figure 5 (As shown).

[0046] The inner side of the furnace wall of the quick-drying section 4 is provided with a heat insulation layer 7; there are 4 sets of sludge atomizing spray guns 4-1 and cooling water spray guns 4-2; the vertical spray opening angle of the sludge atomizing spray guns 4-1 and cooling water spray guns 4-2 is 45° and the horizontal spray opening angle is 135°.

[0047] The inner side of the furnace wall of the dust removal section 5 is provided with a heat insulation layer 7; the ceramic tube filter is equipped with a compressed air back-blowing dust removal device.

[0048] A method for operating a sludge incinerator includes the following processes:

[0049] 1) After the ignition burner 1-4 ignites and burns, it heats the air to above 850°C. The hot flue gas is evenly distributed into the furnace through the air distribution plate 1-3. The temperature inside the incinerator is kept uniform through multiple auxiliary burners 3-1 set at the bottom of the furnace.

[0050] 2) The sludge is sprayed into the furnace in the middle of the quick-drying section 4 through the sludge atomizing spray gun 4-1, and exchanges heat with the hot flue gas introduced from the rising section 3. It is instantly dehydrated into sludge dry powder with a particle size of 60-120 mesh and a moisture content of 20%-25%. The sludge dry powder is contacted with the low-velocity hot flue gas to achieve suspension combustion, and is burned off as it falls into the rising section 3 and the variable diameter section 2. The denser burnt ash and unburned particles fall into the ash and slag pool 2-1 for final combustion.

[0051] 3) Water vapor released from the sludge flows upward with the hot flue gas. The dried fine sludge particles are carried by the rising hot flue gas to the dust removal section. After being intercepted by the ceramic tube filter, they combine with ash and gradually agglomerate and grow larger. Finally, they are blown back into the furnace during the backflushing cleaning until they are burned out. The clean flue gas after dust removal in the dust removal section 5 carries a large amount of water vapor and is discharged from the sludge incinerator in the smoke collection section 6.

[0052] The inlet air velocity of wind chamber 1 shall not exceed 10 m / s; the air velocity at the small hole on the neck of the wind cap on the air distribution plate 1-3 shall be 35-45 m / s; the hot flue gas velocity in the rising section 3 shall be less than 1 m / s; the hot flue gas temperature at the outlet of the rising section 3 shall not be less than 850℃; the furnace pressure shall be maintained at -90 to -110 Pa; and the target flue gas temperature at the outlet of the smoke collection section 6 shall be 120℃.

[0053] Temperature is measured using outlet thermometer 6-2. When the outlet flue gas temperature is below 120℃, auxiliary burner 3-1 is turned on for auxiliary heating. When the outlet flue gas temperature is above 120℃, the output temperature of ignition burner 1-4 is reduced or auxiliary burner 3-1 is turned off. If the outlet flue gas temperature continues to rise, the sludge injection rate is increased. If the outlet flue gas temperature still rises and reaches 180℃ after taking the above measures, emergency cooling water is injected through cooling water spray gun 4-2 to cool it down.

[0054] The sludge incinerator described in this invention can treat sludge with a moisture content of about 80% generated from domestic sewage treatment plants. It can be directly fed into the furnace for incineration without dewatering, and the drying, incineration and primary dust removal of sludge are integrated into the same incinerator.

[0055] The upper part of the sludge incinerator is a vertical cylindrical structure, and the lower part connects to the air chamber 1 after a diameter change. Specifically, the sludge incinerator consists of, from bottom to top, the air chamber 1, the diameter change section 2, the rising section 3, the quick-drying section 4, the dust removal section 5, and the smoke collection section 6. The sludge flows in the opposite direction to the hot flue gas flow after entering the furnace, which is a counter-current flow. The sludge is mainly in a suspended combustion state, and there is a clear stratification between the combustion zone and the ash and slag pool 2-1. The sludge incinerator described in this invention is an adiabatic incinerator without heat absorption surfaces. Temperature control is achieved through multi-point temperature control, low-temperature combustion is used, and the combustion temperature is controlled at around 850℃. Sludge spray cooling and water spray cooling protection are used, and only one ash and slag overflow port 2-2 is provided.

[0056] The cross-section of wind chamber 1 is square, consisting of a vertical section 1-1 and a horizontal section 1-2. The horizontal section 1-2 has an inclined bottom surface. The inlet air velocity of wind chamber 1 generally does not exceed 10 m / s. A distribution plate 1-3 is located in the middle of the vertical section 1-1. The distribution plate 1-3 consists of a perforated plate (i.e., a multi-hole plate) and air caps. The perforated plate is a perforated flat plate made of steel or cast iron, used to fix the air caps. The dimensions of the perforated plate are adapted to the corresponding internal cross-sectional dimensions of the furnace, with a thickness of 20–35 mm. The air cap insertion holes on the perforated plate are generally arranged in an equilateral triangle, with a hole spacing of 1.3–1.7 times the air cap diameter, and the minimum distance between the cap edges shall not be less than 20 mm. The perforations on the perforated plate are spaced every 1.3–1.5 m... 2 A ash-collecting hole (preferably with a diameter of [missing information]) is opened in the area. The neck of the vent cap has small holes with a diameter of 6-8 mm (preferably 6-8 holes) along its circumference. These holes can be horizontal or angled inwards and downwards at a 15° angle. The vent cap's opening ratio (the ratio of the total area of ​​the holes to the top area of ​​the perforated plate) is 2.2%-2.8%. The air velocity through the holes is 35-45 m / s. Ignition burners 1-4 are installed at the air inlet of the air chamber 1.

[0057] The variable diameter section 2 adopts a round-top, square-bottom structure to achieve the transition between the rising section 3 and the air chamber 1. The angle between the furnace wall of the variable diameter section 2 and the horizontal plane is not less than 60°, and the inner side of the furnace wall is lined with a heat insulation layer 7 to prevent heat loss. In the variable diameter section 2, the flue gas turbulence gradually decreases from bottom to top, and the degree of combustion gradually decreases. An ash overflow port 2-2 is provided 0.5 to 1.5m from the bottom of the variable diameter section 2. The space below the ash overflow port 2-2 and the air distribution plate 1-3 is the ash pool 2-1. The ash accumulated here flows out of the sludge incinerator through the ash overflow port 2-2.

[0058] The ascending section 3 has a cylindrical structure. The inner wall of the ascending section 3 is provided with a heat insulation layer 7. The lower part of the ascending section 3 has multiple (preferably 8) auxiliary burners 3-1 evenly distributed along the circumference. The top of the ascending section 3 has a ventilation guide grille 3-2 made of ventilation beams (allowing for cooling air to pass through). The ventilation beams preferably have a width of 200mm and a spacing of 500mm, arranged in a crisscross pattern. At the hot flue gas outlet of the ascending section 3, multiple sets (preferably 8 sets) of furnace thermometers 3-3 are evenly distributed along the circumference. Each set of furnace thermometers 3-3 corresponds one-to-one with the auxiliary burners 3-1 below, used to control the temperature level of the corresponding area, thereby ensuring the consistency of the temperature field throughout the furnace.

[0059] The quick-drying section 4 is a cylindrical structure with the same diameter as the rising section 3. The inner wall of the quick-drying section 4 is equipped with a heat-insulating layer 7. Multiple sets (preferably four sets) of sludge atomizing spray guns 4-1 are evenly distributed circumferentially in the middle of the quick-drying section 4. A cooling water spray gun 4-2 is placed between two sets of sludge atomizing spray guns 4-1. After the sludge is sprayed from the sludge atomizing spray guns 4-1, it slowly descends under the support of the hot flue gas and dries instantly. Lighter sludge particles will rise with the hot flue gas, combining with dust falling during dust removal and growing, or being intercepted by the ceramic tube filter of the dust removal section 5, and then falling downwards. Multiple sets (preferably four sets) of pressure sensors 4-3 are installed circumferentially at the hot flue gas outlet of the quick-drying section 4, and the furnace pressure is maintained at approximately -100 Pa through interlocking control of the control system.

[0060] The dust removal section 5 is a cylindrical structure with the same diameter as the quick-drying section 4. The inner side of the furnace wall is equipped with a heat insulation layer 7. A ceramic tube filter is used as a dust collector to filter particles larger than 0.3μm. It can intercept most of the unburned sludge and ash and return them to the furnace for incineration. The ceramic tube filter uses compressed air backflushing to achieve online ash removal.

[0061] The flue gas collection section 6 is located at the top of the sludge incinerator and adopts a dome structure. The flue gas outlet is located in the center, and an outlet thermometer 6-2 is installed on the flue gas outlet pipe 6-1. The target control temperature of the outlet flue gas is 120℃. When the temperature is lower than the target value, the auxiliary burner 3-1 is turned on. When the temperature is higher than the target value, the heat output of the ignition burner 1-4 is reduced or the auxiliary burner 3-1 is turned off. If the temperature continues to rise, the sludge injection rate is increased. If there is still no improvement and the temperature rises to 180℃, emergency cooling water is injected to lower the temperature.

[0062] To more intuitively illustrate the present invention, the embodiments of the present invention will be further described in conjunction with the examples. The following examples are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention, including simple variations or equivalent substitutions, are all within the scope of protection of the present invention.

[0063]

Example

[0064] This embodiment uses a sludge incinerator with a daily processing capacity of 300t as an example to illustrate the operation process of the sludge incinerator:

[0065] like Figures 1-6 As shown, the sludge incinerator has a diameter of 10m, the dust removal section 5 has a height of 1.5m, the quick-drying section 4 has a height of 8m, the rising section 3 has a height of 5m, and the variable diameter section 2 has a height of 6m; the upper diameter of the variable diameter section 2 is 10m, the lower diameter is 2.5m×2.5m, and the diameter of the flue gas outlet pipe 6-1 of the smoke collection section 6 is 0.7m.

[0066] In this embodiment, the sludge incinerator is equipped with 4 sets of sludge atomizing spray guns 4-1, 4 sets of cooling water spray guns 4-2, 4 pressure sensors 4-3, 8 furnace thermometers, and 1 outlet thermometer 6-2. The rising section 3 is equipped with 8 auxiliary burners 3-1 and 1 ventilation guide grille 3-2.

[0067] During operation, the burners 1-4 are ignited and started, and the furnace temperature gradually rises. When the furnace temperature reaches 200℃ as measured by the furnace thermometer 3-3, cooling water mist is sprayed into the furnace through the cooling water spray gun 4-2. When the furnace temperature reaches 850℃, the amount of cooling water sprayed is reduced, and sludge is sprayed into the furnace through the sludge atomizing spray gun 4-1. After being sprayed into the furnace through the sludge atomizing spray gun 4-1, the sludge slowly descends under the support of the hot flue gas and dries instantly. Lighter sludge rises with the hot flue gas, combining with the dust falling from the dust removal section 5 or being intercepted by the dust removal section 5 and falling downwards. When the dried sludge falls to the rising section 3, it is further dehydrated and volatiles are released. Upon contact with air, it is gradually ignited, and most of the sludge begins to burn in suspension in the rising section 3. During combustion, the sludge continues to fall to the variable diameter section 2, where the flue gas turbulence gradually increases from top to bottom. After the sludge falls into the ash and slag tank 2-1, it boils and burns in the tank. After the last fixed carbon is burned off, ash and slag are formed and discharged from the ash and slag overflow port 2-2.

[0068] High-pressure primary air blown from the ignition burner 1-4 passes through small holes in the air distribution plate 1-3, causing the ash and sludge in the ash and sludge pool 2-1 above the air distribution plate 1-3 to boil, where the sludge is completely burned. The hot flue gas formed by the combustion of air and sludge moves upward to the upper part of the sludge incinerator, gradually slowing down in the variable diameter section 2. When it reaches the rising section 3, the flue gas velocity is less than 1 m / s, and the flue gas temperature is not less than 850℃ (the heat can be provided by the auxiliary burner 3-1). Eight sets of furnace thermometers 3-3 are evenly arranged circumferentially at the outlet position of the rising section 3, and are set one-to-one with the auxiliary burners 3-1 in the vertical direction. The start-up, shutdown and output temperature control of the auxiliary burners 3-1 in the rising section 3 are determined by the temperature feedback value of the corresponding thermometers 3-3, thereby ensuring the consistency of the temperature field in the rising section 3.

[0069] After the hot flue gas enters the quick-drying section 4, it comes into contact with the sludge and is instantly cooled. The hot flue gas also carries the light sludge upwards. Four sets of pressure sensors 4-3 are evenly arranged along the circumference at the outlet of the quick-drying section 4 to maintain the pressure inside the furnace at around -100Pa.

[0070] After dust removal in dust removal section 5, the flue gas carries only particles smaller than 0.3μm and a large amount of water vapor into flue gas collection section 6, and finally exits the sludge incinerator from flue gas outlet pipe 6-1 of flue gas collection section 6. The target value for the flue gas temperature at flue gas outlet pipe 6-1 is 120℃. The temperature is measured by outlet thermometer 6-2. When the outlet flue gas temperature is below 120℃, auxiliary burner 3-1 is turned on. When the outlet flue gas temperature is above 120℃, the output temperature of ignition burner 1-4 is reduced or auxiliary burner 3-1 is turned off. If the outlet flue gas temperature continues to rise, the sludge injection rate is increased. If the outlet flue gas temperature still rises and reaches 180℃ after taking the above measures, emergency cooling water is injected through cooling water spray gun 4-2 to cool it down.

[0071] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A sludge incinerator, characterized in that, The sludge incinerator is configured from bottom to top as follows: an air chamber, a variable diameter section, an ascending section, a quick-drying section, a dust removal section, and a smoke collection section. The air chamber consists of a vertical section and a horizontal section. The top of the vertical section connects to the variable diameter section, and an air distribution plate is located in the middle of the vertical section. The horizontal section houses the ignition burner. The cross-section of the air chamber is square. The bottom surface of the horizontal section below the vertical section is inclined. The air distribution plate consists of a perforated plate and air caps. Multiple air cap insertion holes are provided on the perforated plate, and the air caps are fixed in corresponding holes. Each air cap consists of a cap top and a cap neck. Multiple 6-8mm small holes are provided along the circumference of the cap neck. The ratio of the total area of ​​the small holes to the top area of ​​the perforated plate (i.e., the air cap opening rate) is 2.2%-2.8%. The hole spacing of the air cap insertion holes is 1.3-1.7 times the diameter of the air cap, and the minimum distance between the edges of each air cap is greater than 20mm. Every 1.3-1.5m... 2 One ash discharge hole is opened within the range; the variable diameter section is a conical cylindrical structure with a small bottom opening and a large top opening, and a round top and square bottom. The angle between the furnace wall of the variable diameter section and the horizontal plane is not less than 60°. The inner side of the furnace wall of the variable diameter section is provided with a heat insulation layer. An ash overflow port is provided on one side of the lower part of the variable diameter section. The ash overflow port is located at a height of 0.5 to 1.5m from the bottom surface of the variable diameter section. The space between the ash overflow port and the air distribution plate is an ash pool; the rising section, quick-drying section and dust removal section are cylindrical structures with the same diameter; the lower part of the rising section is provided with an auxiliary burner, and the upper part is provided with a ventilation guide grille; the middle part of the quick-drying section is provided with sludge atomizing spray guns and cooling water spray guns, and multiple sludge atomizing spray guns and cooling water spray guns are arranged alternately along the circumference; the dust removal section is provided with The system includes a ceramic tube filter; the smoke collection section has a dome structure with a flue gas outlet at the center; the sludge incinerator is also equipped with a temperature and pressure control system; the temperature and pressure control system includes a control system, an inlet thermometer, a furnace thermometer, an outlet thermometer, and a pressure sensor, wherein the inlet thermometer is located on the side wall of the variable diameter section on one side of the ash and slag pool; the furnace thermometer is located on the side wall of the furnace body; the outlet thermometer is located on the flue gas outlet pipe; and the pressure sensor is located on the side wall of the furnace body above the quick-drying section; the inlet thermometer, furnace thermometer, outlet thermometer, and pressure sensor are respectively connected to the control system, which is also connected to the control terminals of the ignition burner, auxiliary burner, sludge atomizing spray gun, and cooling water spray gun.

2. The sludge incinerator according to claim 1, characterized in that, The inner side of the furnace wall in the rising section is provided with a heat insulation layer; there are 8 auxiliary burners, evenly distributed along the circumference; there are 8 furnace thermometers, which are set one by one with the auxiliary burners below; the ventilation guide grille is composed of multiple ventilation beams arranged in a crisscross pattern.

3. A sludge incinerator according to claim 1, characterized in that, The inner side of the furnace wall of the quick-drying section is provided with a heat insulation layer; there are 4 sets of sludge atomizing spray guns and 4 sets of cooling water spray guns; the vertical spray opening angle of the sludge atomizing spray gun and the cooling water spray gun is 45° and the horizontal spray opening angle is 135°.

4. A sludge incinerator according to claim 1, characterized in that, The inner wall of the dust removal section is equipped with a heat insulation layer; the ceramic tube filter is equipped with a compressed air backflushing and dust removal device.

5. A method for operating a sludge incinerator as described in any one of claims 1 to 4, characterized in that, The process includes the following: 1) After the ignition burner is ignited and combusted, it heats the air to above 850°C. The hot flue gas is evenly distributed into the furnace through the air distribution plate. Multiple auxiliary burners set in the lower part of the furnace maintain a uniform temperature in the incinerator. 2) The sludge is sprayed into the furnace in the middle of the quick-drying section through a sludge atomizing spray gun. It comes into contact with the hot flue gas introduced from the rising section for heat exchange and is instantly dehydrated into sludge dry powder with a particle size of 60-120 mesh and a moisture content of 20%-25%. The sludge dry powder comes into contact with the low-velocity hot flue gas to achieve suspension combustion and is burned off as it falls into the rising section and the diameter changing section. The denser burnt ash and unburned particles fall into the ash and slag pool for final combustion. 3) Water vapor released from the sludge flows upward with the hot flue gas. The dried fine sludge particles are carried by the rising hot flue gas to the dust removal section. After being intercepted by the ceramic tube filter, they combine with ash and gradually agglomerate and grow larger. Finally, they are blown back into the furnace during the backflushing cleaning until they are burned out. The clean flue gas after dust removal in the dust removal section carries a large amount of water vapor and is discharged from the sludge incinerator from the smoke collection section.

6. The operating method of a sludge incinerator according to claim 5, characterized in that, The inlet wind speed of the wind chamber shall not exceed 10 m / s; the wind speed at the small hole on the neck of the wind cap on the wind distribution plate shall be 35 to 45 m / s; the hot flue gas velocity in the rising section shall be less than 1 m / s; the hot flue gas temperature at the outlet of the rising section shall not be less than 850℃; the furnace pressure shall be maintained at -90 to -110 Pa; and the target flue gas temperature at the outlet of the smoke collection section shall be 120℃.

7. The operating method of a sludge incinerator according to claim 6, characterized in that, Temperature is measured by an outlet thermometer. When the outlet flue gas temperature is below 120°C, the auxiliary burner is turned on for auxiliary heating. When the outlet flue gas temperature is above 120°C, the output temperature of the ignition burner is reduced or the auxiliary burner is turned off. If the outlet flue gas temperature continues to rise, the sludge injection rate is increased. If the outlet flue gas temperature still rises and reaches 180°C after taking the above measures, emergency cooling water is injected through a cooling water spray gun to cool it down.

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