Sludge incinerator and working method thereof

Abstract

The invention relates to a sludge incinerator and a working method thereof. The sludge incinerator is sequentially provided with an air chamber, a reducing section, an ascending section, a quick-drying section, a dust removal section and a smoke collection section from bottom to top. The air chamber is composed of a vertical section and a horizontal section, the vertical section is provided with an air distribution plate, and the horizontal section is provided with an ignition burner. The reducing section is provided with an ash overflow port, and an ash pool is arranged between the ash overflow port and the air distribution plate; the ascending section is provided with an auxiliary burner and a ventilation flow guide grid; the quick-drying section is provided with a sludge atomizing spray gun and a cooling water spray gun; the dedusting section is provided with a ceramic tube filter; the smoke collecting section is provided with a smoke outlet; the sludge incinerator is further provided with a temperature and pressure control system. According to the sludge incinerator, the sludge dewatering and burning processes are continuously completed in the same incinerator body, the closed incinerator body structure is adopted, sludge is directly incinerated without being dewatered, the technological process is shortened, and the possibility that the sludge or peculiar smell overflows in the operation process of a sludge treatment system is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of sludge treatment, and in particular to a sludge incinerator and a working method thereof. Background Art

[0002] Sludge incineration is a sludge treatment process that uses an incinerator to heat and dry the dehydrated sludge, and then uses high temperature to oxidize the organic matter in the sludge, turning the sludge into a small amount of ash. Therefore, it is a reduction, stabilization, and harmless treatment method that can completely remove water and organic matter in the sludge and kill pathogens.

[0003] Currently, the most widely used process involves first dewatering the sludge using mechanical sludge dewatering equipment (such as centrifugal dewatering machines, plate and frame filter presses, and belt presses), then subjecting the dewatered sludge to low-temperature thermal drying using sludge drying equipment (such as drum drying equipment, blade drying equipment, disc drying equipment, and fluidized bed drying equipment). The dehydrated sludge is then incinerated in an incinerator. However, the above process has drawbacks: a lengthy process flow and the inevitable presence of open interfaces between the main equipment and various auxiliary devices. These open interfaces can lead to sludge leakage or odor emission, resulting in severe air odor near the process system, deteriorating the working environment, and directly impacting the lives of nearby residents. For example, plate and frame filter presses must be operated openly during dosing, preparation, and sludge discharge, exposing the sludge cake to the atmosphere. This creates a harsh operating environment near the equipment and allows odor to easily escape. For example, conventional spray drying equipment requires external three-stage dust collectors, rotary kilns and other equipment. During the material transportation process, material overflow or odor overflow is very likely to occur at the scraper conveyor, air duct expansion joint, feeding port, dust collector and other parts. Summary of the Invention

[0004] The present invention provides a sludge incinerator and a working method thereof, which continuously completes the sludge dehydration and combustion processes in the same furnace body. A closed furnace body structure is adopted, and the sludge is directly incinerated without dehydration, thereby shortening the process flow and eliminating the possibility of sludge or odor overflow during the operation of the sludge treatment system.

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

[0006] A sludge incinerator, which is successively provided with an air chamber, a variable-diameter section, a rising section, a quick-drying section, a dust-removing section and a smoke-collecting section from bottom to top; the air chamber is composed of a vertical section and a horizontal section, the top of the vertical section is connected to the variable-diameter section, a wind-distributing plate is arranged in the middle of the vertical section, and an ignition burner is arranged in the horizontal section; the variable-diameter section is a conical cylinder structure with a small lower opening and a large upper opening, a slag overflow port is arranged on one side of the lower part of the variable-diameter section, and the space between the slag overflow port and the wind-distributing plate is a slag pool; the rising section, the quick-drying section and the dust-removing section are cylindrical structures with the same diameter; an auxiliary burner is arranged at the lower part of the rising section, and a ventilation and flow-guiding grille is arranged at the upper part; a sludge atomizing spray gun and a cooling water spray gun are arranged in the middle of the quick-drying section, and a plurality of sludge atomizing spray guns and cooling water spray guns are arranged at intervals along the circumferential direction; a ceramic tube filter is arranged in the dust-removing section; the smoke-collecting section is a dome structure, and a flue gas outlet is arranged at the central part; the sludge incinerator is also provided 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. Among them, the inlet thermometer is arranged on the side wall of the variable-diameter section on one side of the slag pool; the furnace thermometer is arranged on the side wall of the furnace body of the furnace chamber; the outlet thermometer is arranged on the flue gas outlet pipeline; the pressure sensor is arranged on the side wall of the furnace body at the upper part of the quick-drying section; the inlet thermometer, the furnace thermometer, the outlet thermometer and the pressure sensor are respectively connected to the control system, and the control system is additionally connected to the control ends of the ignition burner, the auxiliary burner, the sludge atomizing spray gun and the 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 an inclined surface; the wind-distributing plate is composed of a perforated plate and wind caps; a plurality of wind cap insertion holes are opened on the perforated plate, and the wind caps are fixedly arranged in the wind cap insertion holes one by one; the wind cap is composed of a cap top and a cap neck, and a plurality of 6-8 mm small holes are opened along the circumferential direction of the cap neck. The ratio of the total area of the small holes to the top area of the perforated plate, that is, the wind cap opening ratio, is 2.2% - 2.8%; the hole pitch of the wind cap insertion holes is 1.3 - 1.7 times the diameter of the wind cap, and the minimum distance between the rims of each wind cap is greater than 20 mm; one ash discharge hole is opened within every 1.3 - 1.5 m 2 range on the wind-distributing plate.

[0008] The variable-diameter section is a conical structure with a round top and a square bottom, and the included angle between the furnace wall of the variable-diameter section and the horizontal plane is not less than 60°; a heat-insulating layer is arranged on the inner side of the furnace wall of the variable-diameter section, and the slag overflow port is arranged at a height of 0.5 - 1.5 m from the bottom surface of the variable-diameter section.

[0009] A heat-insulating layer is arranged on the inner side of the furnace wall of the rising section; there are 8 auxiliary burners, which are evenly distributed along the circumferential direction; there are 8 furnace thermometers, which are arranged in one-to-one correspondence with the auxiliary burners below; the ventilation and flow-guiding grille is composed of a plurality of ventilation beams arranged in a vertical and horizontal cross pattern.

[0010] The inner side of the furnace wall of the quick-drying section is provided with a heat-insulating layer; there are 4 groups of sludge atomizing spray guns and cooling water spray guns respectively; the vertical spraying opening angles of the sludge atomizing spray guns and the cooling water spray guns are both 45°, and the horizontal spraying opening angles are both 135°.

[0011] The inner side of the furnace wall of the dust removal section is provided with a heat-insulating layer; the ceramic tube filter is provided with a compressed air back-blowing dust cleaning device.

[0012] A working method of a sludge incinerator includes the following processes:

[0013] 1) After the ignition burner ignites and burns, the air is heated to above 850 °C, and the hot flue gas is evenly distributed into the furnace through the air distribution plate; through a plurality of auxiliary burners arranged at the lower part of the furnace, the temperature in the incinerator is maintained evenly.

[0014] 2) The sludge is sprayed into the furnace in the middle of the quick-drying section through the sludge atomizing spray gun, contacts and exchanges heat with the hot flue gas introduced from the rising section, 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 contacts the low-flow hot flue gas to achieve suspension incineration, and is burned out during the process of falling to the rising section and the variable-diameter section; the burned ash and unburned particles with large density fall into the ash pit for final incineration.

[0015] 3) The water vapor separated 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, are intercepted by the ceramic tube filter, combine with the ash and gradually agglomerate and become larger, and are finally blown back into the furnace during back-blowing dust cleaning until they are burned out; the clean flue gas after dust removal in the dust removal section discharges from the smoke collection section of the sludge incinerator with a large amount of water vapor.

[0016] The inlet wind speed of the air chamber does not exceed 10 m / s; the wind speed at the small holes on the wind cap neck of the air distribution plate is 35-45 m / s; the hot flue gas flow rate in the rising section is lower than 1 m / s; the hot flue gas temperature at the outlet of the rising section is not lower than 850 °C; the furnace pressure is maintained at -90 to -110 Pa; the target temperature of the flue gas at the outlet of the smoke collection section is 120 °C.

[0017] Measure the temperature through the outlet thermometer. When the outlet flue gas temperature is lower than 120 °C, turn on the auxiliary burner for auxiliary heating; when the outlet flue gas temperature is higher than 120 °C, weaken the output temperature of the ignition burner or turn off the auxiliary burner; if the outlet flue gas temperature continues to increase, increase the sludge injection amount; if after taking the above measures, the outlet flue gas temperature still rises and reaches 180 °C, spray emergency cooling water through the cooling water spray gun to cool down.

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

[0019] 1) The sludge incinerator of the present invention is conducive to shortening the process flow of sludge treatment, reducing the number of equipment, and lowering the equipment failure rate.

[0020] 2) The sludge incinerator of the present invention integrates sludge drying and incineration, with a small footprint (for a sludge incinerator with a daily sludge treatment capacity of 300 tons / d, the floor area is only 800 m 2 ), and has strong adaptability to fluctuations in the upstream and downstream material inflows and outflows.

[0021] 3) The sludge incinerator of the present invention has good sealing performance, preventing the odor overflow that is prone to occur during the sludge treatment process, and having little impact on the environment.

[0022] 4) The sludge incinerator of the present invention has high incineration efficiency; before the ash slag is discharged, it burns in a boiling state in the ash slag pool, the carbon is completely burned, and the heat loss of the ash slag is small. Only one ash slag overflow port is required to discharge the ash slag outside the furnace.

[0023] 5) After incinerating the sludge, the sludge incinerator of the present invention basically does not generate fly ash, eliminating the need to set up a bag filter. The fly ash treatment cost is extremely low, and the operating cost is small.

[0024] 6) The sludge incinerator of the present invention is environmentally friendly. Adopting the low-temperature suspension incineration method, the nitrogen oxide generation amount is lower than 200 mg / m 3 ; no chemical pretreatment is required for the sludge, no Cl is added, and the sludge suspension incineration state exceeds 2 s, which can decompose the original dioxins in the sludge; the sludge drying process is equivalent to a rapid cooling process, without a temperature range for dioxin regeneration, and there is no dioxin pollution. Adding CaO into the furnace can achieve in-furnace desulfurization.

[0025] 7) The sludge incinerator of the present invention uses a sludge atomizing spray gun. The mist droplets after sludge atomization are very small, and the dried sludge particles are extremely small. The combustion of the sludge is mainly completed in the rising section and the variable diameter section. Only the residual carbon is burned in the ash slag pool, with a low heat release. Therefore, there is no need to set up buried tube cooling equipment in the ash slag pool, but an ignition burner is required to provide temperature support.

[0026] 8) The sludge incinerator of the present invention sets multiple auxiliary burners and ventilation and cooling ventilation diversion grilles in the high-temperature area of the rising section, which can obtain a stable flue gas flow field and temperature field, ensure more uniform sludge drying, good drying effect, and more stable combustion process.

[0027] 9) The sludge incinerator of the present invention has good operation safety. The upper part of the furnace chamber is cooled by spraying sludge (further water spraying can be carried out), and the open flame combustion in the rising section and the variable diameter section can prevent the occurrence of dust deflagration.

[0028] 9) The sludge incinerator of the present invention has a simple structure, low maintenance cost, long service life, simple operation and low operating cost; the sludge atomizing spray gun adopts a horizontal spraying method, without considering the spraying angle, easy for workers to operate, short maintenance and replacement time, and low cost; the sludge incinerator has a low combustion temperature, a long operating time of the insulated furnace, and low maintenance cost; the dust removal section uses ceramic filter as the dust collector, which is resistant to high temperature, long service life and low maintenance cost; the incinerator has no pressure components and is a non-pressure vessel, with low operation difficulty and low cost; no drug addition is required for sludge pretreatment, and there is no drug cost and dosing equipment investment.

[0029] 10) The sludge incinerator described in the present invention has great flexibility in sludge drying operation and low requirements for the atomizer. It adopts a countercurrent drying method of flue gas and sludge. Compared with the cocurrent drying method, the sludge drying time is longer; because the hot flue gas and the sludge flow in the opposite direction, when the larger sludge particles flow downward after the sludge is atomized, they will not fall rapidly due to the lifting effect of the hot flue gas, thereby ensuring the incineration effect of the ascending section; when the sludge particles after atomization are small, the sludge particles will flow upward with the hot flue gas. Since there is enough drying space above, the sludge drying can be ensured to be successful; the sludge atomization spray gun is set at a high height and a cooling water spray gun is provided at the same time to control the temperature to ensure that the temperature field is within a reasonable range.

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

[0031] 12) The present invention uses an incinerator to achieve suspended combustion. Compared with using a rotary kiln as an incineration device, the equipment investment cost is low and the failure rate is low.

[0032] 13) The multiple auxiliary burners installed in the furnace of the sludge incinerator of the present invention are open flame burners, which form open flame conditions in the large cross-section furnace, have good redundancy, and the dust concentration in the furnace is controlled at 11g / m 3 The following ensures that explosive dust explosion conditions will not be formed, and safety is high.

[0033] 14) After using the sludge incinerator of the present invention, the cost of water treatment after sludge incineration is low, and the liquid water converted from the water vapor in the flue gas after condensation contains only a small amount of inorganic matter; while the water removed after dehydrating the sludge using filter press dehydration equipment, indirect drying equipment or circulating air drying type dehydration equipment contains difficult-to-treat organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a sludge incinerator described in the present invention.

[0035] Figure 2It is the plan layout drawing of the sludge spray gun and the cooling water spray gun described in the present invention.

[0036] Figure 3 It is the plan layout drawing of the thermometer at the outlet of the ascending section described in the present invention.

[0037] Figure 4 It is the plan layout drawing of the burner of the ascending section described in the present invention.

[0038] Figure 5 It is the plan layout drawing of the ventilation beam described in the present invention.

[0039] Figure 6 It is the plan layout drawing of the pressure sensor at the outlet of the quick-drying section described in the present invention.

[0040] In the figure: 1. Air chamber 1-1. Vertical section 1-2. Horizontal section 1-3. Air distribution plate 1-4. Ignition burner 2. Reducing section 2-1. Ash pit 2-2. Ash overflow port 2-3. Inlet thermometer 3. Ascending section 3-1. Auxiliary burner 3-2. Ventilation and flow guiding 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 manners

[0041] The following further explains the detailed implementation manners of the present invention with reference to the accompanying drawings:

[0042] As Figure 1 shown, for a sludge incinerator described in the present invention, the sludge incinerator is successively provided with an air chamber 1, a reducing section 2, an ascending section 3, a quick-drying section 4, a dust removal section 5 and a smoke collection section 6 from bottom to top; the air chamber 1 is composed of a vertical section 1-1 and a horizontal section 1-2, the top of the vertical section 1-1 is connected to the reducing section 2, a air distribution plate 1-3 is arranged in the middle of the vertical section 1-1, and an ignition burner 1-4 is arranged on the horizontal section 1-2; the reducing section 2 is a conical cylinder structure with a small lower opening and a large upper opening, an ash overflow port 2-2 is arranged on one side of the lower part of the reducing section 2, and the space between the ash overflow port 2-2 and the air distribution plate 1-3 is an ash pit 2-1; the ascending section 3, the quick-drying section 4 and the dust removal section 5 are cylindrical structures with the same diameter; an auxiliary burner 3-1 is arranged at the lower part of the ascending section 3, and a ventilation and flow guiding grille 3-2 is arranged at the upper part; a sludge atomizing spray gun 4-1 and a cooling water spray gun 4-2 are arranged in the middle of the quick-drying section 4, and a plurality of sludge atomizing spray guns 4-1 and cooling water spray guns 4-2 are arranged at intervals along the circumferential direction (such as Figure 2as shown); the dust removal section 5 is provided with a ceramic tube filter; the smoke collection section 6 is of a dome structure, and a flue gas outlet is provided at the central part; the sludge incinerator is also provided 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. Among them, the inlet thermometer 2-3 is arranged on the side wall of the reduced diameter section 2 on one side of the ash pit 2-1; the furnace thermometer 3-3 is arranged on the side wall of the furnace body of the furnace (as Figure 3 shown); the outlet thermometer 6-2 is arranged on the flue gas outlet pipe 6-1; the pressure sensor 4-3 is arranged on the side wall of the furnace body above the quick drying section 4 (as Figure 6 shown); the inlet thermometer 2-3, the furnace thermometer 3-3, the outlet thermometer 6-2 and the pressure sensor 4-3 are respectively connected to the control system, and the control system is additionally connected to the control ends of the ignition burner 1-4, the auxiliary burner 3-1, the sludge atomizing spray gun 4-1 and the 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; a plurality of air cap insertion holes are opened on the perforated plate, and the air caps are fixedly arranged in the air cap insertion holes one by one; the air cap is composed of a cap top and a cap neck, and a plurality of small holes with a diameter of 6-8 mm are opened along the circumferential direction of the cap neck. The ratio of the total area of the small holes to the top area of the perforated plate, that is, the air cap opening ratio, is 2.2% - 2.8%; the hole pitch 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 20 mm; one ash discharge hole is opened within every 1.3 - 1.5 m 2 range on the air distribution plate 1-3.

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

[0045] A heat preservation and insulation layer 7 is arranged on the inner side of the furnace wall of the rising section 3; there are 8 auxiliary burners 3-1, which are evenly distributed along the circumferential direction (as Figure 4 shown); there are 8 furnace thermometers 3-3 (as Figure 3 shown), which are arranged in one-to-one correspondence with the auxiliary burners 3-1 below; the ventilation and flow guiding grille 3-2 is composed of a plurality of ventilation beams arranged vertically and horizontally (as Figure 5 shown).

[0046] A heat preservation and insulation layer 7 is arranged on the inner side of the furnace wall of the quick drying section 4; there are 4 groups of sludge atomizing spray guns 4-1 and 4 groups of cooling water spray guns 4-2 respectively; the vertical spraying opening angles of the sludge atomizing spray gun 4-1 and the cooling water spray gun 4-2 are both 45°, and the horizontal spraying opening angles are both 135°.

[0047] An insulating layer 7 is provided on the inner side of the furnace wall of the dust removal section 5; the ceramic tube filter is provided with a compressed air backwashing and dust cleaning device.

[0048] A working method of a sludge incinerator includes the following processes:

[0049] 1) After the ignition burner 1-4 is ignited and burns, the air is heated to above 850 °C, and the hot flue gas is evenly distributed into the furnace through the air distribution plate 1-3; through a plurality of auxiliary burners 3-1 arranged at the lower part of the furnace, the temperature in the incinerator is maintained evenly.

[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, contacts and exchanges heat with the hot flue gas introduced from the rising section 3, 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 contacts the low-flow hot flue gas to achieve suspended incineration, and is burned out during the process of falling to the rising section 3 and the variable diameter section 2; the burned ashes and unburned particles with large density fall into the ash pit 2-1 for final incineration.

[0051] 3) The water vapor separated 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, are intercepted by the ceramic tube filter, combine with the ash, and gradually gather and become larger. Finally, they are blown back into the furnace during backwashing and dust 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 through the smoke collecting section 6.

[0052] The inlet air velocity of the air chamber 1 does not exceed 10 m / s; the air velocity at the small holes on the wind cap neck of the air distribution plate 1-3 is 35-45 m / s; the hot flue gas velocity in the rising section 3 is lower than 1 m / s; the temperature of the hot flue gas at the outlet of the rising section 3 is not lower than 850 °C; the furnace pressure is maintained at -90 to -110 Pa; the target temperature of the flue gas at the outlet of the smoke collecting section 6 is 120 °C.

[0053] The temperature is measured by the outlet thermometer 6-2. When the outlet flue gas temperature is lower than 120 °C, the auxiliary burner 3-1 is turned on for auxiliary heating; when the outlet flue gas temperature is higher than 120 °C, the output temperature of the ignition burner 1-4 is weakened or the auxiliary burner 3-1 is turned off; if the outlet flue gas temperature continues to increase, the sludge injection amount is increased; if after taking the above measures, the outlet flue gas temperature still rises and reaches 180 °C, emergency cooling water is sprayed through the cooling water spray gun 4-2 to cool down.

[0054] Using the sludge incinerator described in the present invention to treat sludge with a moisture content of about 80% generated by a domestic sewage treatment plant, dehydration is not required, and the sludge can be directly incinerated in the furnace, and the drying, incineration and primary dust removal of the sludge are completed in the same incinerator.

[0055] The upper part of the sludge incinerator is of a vertical cylindrical structure, and the lower part is connected to the air chamber 1 after a diameter change. Specifically, the sludge incinerator successively includes an air chamber 1, a diameter-changing section 2, a rising section 3, a quick-drying section 4, a dust-removing section 5, and a smoke-collecting section 6 from bottom to top. The flow direction of the sludge after entering the furnace is opposite to that of the hot flue gas, that is, a countercurrent flow mode. The incineration state of the sludge is mainly a suspended incineration state, and there is an obvious stratification between the incineration area and the ash slag pool 2-1. The sludge incinerator described in the present invention is an adiabatic incinerator without a heat-absorbing surface. The temperature control adopts multi-point temperature control, and low-temperature incineration is used. The incineration temperature is controlled at about 850°C. The sludge spray cooling and water spraying are used for cooling and protection, and only one ash slag overflow port 2-2 is provided.

[0056] The cross-section of the air chamber 1 is square and is composed 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 the air chamber 1 generally does not exceed 10 m / s. A wind distribution plate 1-3 is provided in the middle of the vertical section 1-1. The wind distribution plate 1-3 is composed of a perforated plate (i.e., a perforated plate) and wind caps. The perforated plate is a perforated flat plate made of steel plate or cast iron plate and is used to fix the wind caps. The size of the perforated plate is adapted to the inner cross-sectional size of the corresponding part of the furnace chamber, and the thickness is 20-35 mm. The wind cap sockets on the perforated plate are generally arranged in an equilateral triangle, and the hole pitch is 1.3-1.7 times the diameter of the wind cap. The minimum distance between the cap edges shall not be less than 20 mm. Every 1.3-1.5 m 2 area is provided with an ash discharge hole (preferably with a diameter of ). The wind cap neck is provided with small holes with a diameter of 6-8 mm (preferably the number is 6-8) along the circumferential direction. The small holes can be horizontally opened or inclined downward by 15° inward. The opening ratio of the wind cap, that is, the ratio of the total area of the small holes to the top area of the perforated plate, is 2.2%-2.8%. The small hole air velocity is 35-45 m / s; the air inlet of the air chamber 1 is provided with an ignition burner 1-4.

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

[0058] The ascending section 3 is a cylindrical structure. An insulating layer 7 is provided on the inner side of the furnace wall of the ascending section 3. At the lower part of the ascending section 3, a plurality of (preferably 8) auxiliary burners 3-1 are evenly distributed along the circumferential direction. At the top of the ascending section 3, a ventilation and flow guiding grille 3-2 made of ventilation beams (through which cooling air can pass) is provided. The preferred dimensions of the ventilation beams are: width 200 mm, spacing 500 mm, arranged in a crisscross pattern. At the position of the hot flue gas outlet of the ascending section 3, a plurality of groups (preferably 8 groups) of furnace thermometers 3-3 are evenly distributed along the circumferential direction. Each group of furnace thermometers 3-3 is arranged in one-to-one correspondence with the auxiliary burner 3-1 below, for controlling the temperature level of the corresponding area, so as to ensure the consistency of the temperature field in each part of the furnace.

[0059] The quick-drying section 4 is a cylindrical structure, with the same diameter as the ascending section 3. An insulating layer 7 is provided on the inner side of the furnace wall of the quick-drying section 4. In the middle of the quick-drying section 4, a plurality of groups (preferably 4 groups) of sludge atomizing spray guns 4-1 are evenly distributed along the circumferential direction. One group of cooling water spray guns 4-2 is arranged between every two groups of sludge atomizing spray guns 4-1. After the sludge is sprayed out from the sludge atomizing spray gun 4-1, it slowly descends under the lifting action of the hot flue gas and is instantaneously dried. The lighter sludge particles will move upward with the hot flue gas, combine and grow with the dust falling during dust removal, or be intercepted by the ceramic tube filter in the dust removal section 5, and then fall downward. At the hot flue gas outlet of the quick-drying section 4, a plurality of groups (preferably 4 groups) of pressure sensors 4-3 are arranged along the circumferential direction. Through the interlocking control of the control system, the furnace pressure is maintained at about -100 Pa.

[0060] The dust removal section 5 is a cylindrical structure, with the same diameter as the quick-drying section 4. An insulating layer 7 is provided on the inner side of the furnace wall. A ceramic tube filter is used as the dust collector, for filtering particles above 0.3 μm. It can intercept the vast majority of unburned sludge and ash and return them to the furnace for burning. The ceramic tube filter realizes online ash cleaning by means of compressed air backwashing.

[0061] The smoke collecting section 6 is located at the top of the sludge incinerator, adopting a dome structure. The flue gas outlet is arranged at the central position. An outlet thermometer 6-2 is provided on the flue gas outlet pipe 6-1. The target control temperature of the outlet flue gas is 120 °C. 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 weakened or the auxiliary burner 3-1 is turned off. If the temperature continues to rise, the sludge injection amount is increased. If there is still no improvement and the temperature rises to 180 °C, emergency cooling water is sprayed in for cooling.

[0062] In order to more intuitively reflect the present invention, the implementation manner of the present invention will be further described in combination with embodiments. The following embodiments are only the preferred specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be obtained obviously by those skilled in the art within the technical scope disclosed by the present invention, including simple changes or equivalent replacements, is within the protection scope of the present invention.

[0063]

Example

[0064] Taking a sludge incinerator with a daily treatment capacity of 300t as an example, this example describes the operation process of the sludge incinerator:

[0065] As Figures 1-6 shown, the diameter of the sludge incinerator is 10m, the height of the dust removal section 5 is 1.5m, the height of the quick-drying section 4 is 8m, the height of the rising section 3 is 5m, and the height of the variable diameter section 2 is 6m; the upper diameter of the variable diameter section 2 is 10m, the lower size 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 example, the sludge incinerator is equipped with 4 groups of sludge atomizing spray guns 4-1, 4 groups of cooling water spray guns 4-2, and another 4 pressure sensors 4-3, 8 furnace thermometers and 1 outlet thermometer 6-2 are provided. The rising section 3 is provided with 8 auxiliary burners 3-1 and 1 ventilation and diversion grille 3-2.

[0067] During operation, the ignition burner 1-4 is ignited and started, and the temperature in the furnace gradually rises. When the furnace thermometer 3-3 measures that the temperature in the furnace rises to 200°C, cooling water mist is sprayed through the cooling water spray gun 4-2. When the temperature in the furnace rises to 850°C, the spraying amount of cooling water is reduced, and sludge is sprayed through the sludge atomizing spray gun 4-1. After the sludge is sprayed into the furnace from the sludge atomizing spray gun 4-1, it slowly descends under the lifting action of the hot flue gas and is instantly dried. The lighter sludge will move upward with the hot flue gas, combine and grow with the dust falling after dust removal in the dust removal section 5 or be intercepted by the dust removal section 5 and then fall, and move downward. When the dried sludge falls to the rising section 3, it is further dehydrated, volatile components are released, and it is gradually ignited after contacting the air. Most of the sludge starts to burn suspended in the rising section 3. During the combustion process, the sludge continues to fall to the variable diameter section 2, where the flue gas turbulence gradually strengthens from top to bottom. After the sludge falls into the ash slag pool 2-1, it burns turbulently in the pool, and after burning out the final fixed carbon, ash slag is formed, and the ash slag is discharged from the ash slag overflow port 2-2.

[0068] The high-pressure primary air blown out from the ignition burner 1-4 passes through the small holes on the air distribution plate 1-3, causing the ash slag in the ash slag pool 2-1 above the air distribution plate 1-3 to boil, and the sludge burns out here. The air and the hot flue gas formed after the sludge burns move upward in the sludge incinerator, gradually decelerate in the variable diameter section 2, and the flue gas flow velocity is lower than 1m / s when reaching the rising section 3, and the flue gas temperature is not lower than 850°C (the heat can be provided by the auxiliary burner 3-1). 8 groups of furnace thermometers 3-3 are evenly arranged along the circumferential direction at the outlet position of the rising section 3, and are arranged in one-to-one correspondence with the auxiliary burner 3-1 in the vertical direction; the start-stop and output temperature control of the auxiliary burner 3-1 in the rising section 3 are determined by the temperature feedback value of the corresponding thermometer 3-3, so as to ensure the consistency of the temperature field in the rising section 3.

[0069] The hot flue gas enters the quick-drying section 4 upwards and contacts the sludge, instantaneously cooling down, and the hot flue gas carries the light sludge and moves upwards. Four groups of pressure sensors 4-3 are evenly arranged along the circumferential direction at the outlet of the quick-drying section 4 to keep the pressure in the furnace at about -100 Pa.

[0070] After the flue gas is dust-removed in the dust-removing section 5, it only carries particles below 0.3 μm and a large amount of water vapor into the smoke collection section 6, and finally is discharged from the flue gas outlet pipe 6-1 of the smoke collection section 6 out of the sludge incinerator. The target value of the flue gas temperature at the flue gas outlet pipe 6-1 is 120 °C; the temperature is measured by the outlet thermometer 6-2. When the outlet flue gas temperature is lower than 120 °C, the auxiliary burner 3-1 is turned on. When the outlet flue gas temperature is higher than 120 °C, the output temperature of the ignition burner 1-4 is weakened or the auxiliary burner 3-1 is turned off. If the outlet flue gas temperature continues to increase, the sludge injection amount is increased; if after taking the above measures, the outlet flue gas temperature still rises and reaches 180 °C, emergency cooling water is sprayed in through the cooling water spray gun 4-2 to cool down.

[0071] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, should be covered within the protection scope of the present invention.

Claims

1. A sludge incinerator, characterized in that, The sludge incinerator is successively provided with an air chamber, a reduced-diameter section, an ascending section, a quick-drying section, a dust-removing section and a smoke-collecting section from bottom to top; the air chamber consists of a vertical section and a horizontal section, the top of the vertical section is connected to the reduced-diameter section, a wind-distributing plate is arranged in the middle of the vertical section, and an ignition burner is arranged in the horizontal section; the reduced-diameter section is a conical cylindrical structure with a small lower opening and a large upper opening, a slag overflow port is arranged on one side of the lower part of the reduced-diameter section, and the space between the slag overflow port and the wind-distributing plate is a slag pool; the ascending section, the quick-drying section and the dust-removing section are cylindrical structures with the same diameter; an auxiliary burner is arranged at the lower part of the ascending section, and a ventilation and flow-guiding grille is arranged at the upper part; a sludge atomizing spray gun and a cooling water spray gun are arranged in the middle of the quick-drying section, and a plurality of sludge atomizing spray guns and cooling water spray guns are arranged at intervals along the circumferential direction; a ceramic tube filter is arranged in the dust-removing section; the smoke-collecting section is a dome structure, and a flue gas outlet is arranged at the central part; the sludge incinerator is also provided 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. Among them, the inlet thermometer is arranged on the side wall of the reduced-diameter section on one side of the slag pool; the furnace thermometer is arranged on the side wall of the furnace body of the furnace chamber; the outlet thermometer is arranged on the flue gas outlet pipeline; the pressure sensor is arranged on the side wall of the furnace body at the upper part of the quick-drying section; the inlet thermometer, the furnace thermometer, the outlet thermometer and the pressure sensor are respectively connected to the control system, and the control system is additionally connected to the control ends of the ignition burner, the auxiliary burner, the sludge atomizing spray gun and the cooling water spray gun.

2. The sludge incinerator according to claim 1, wherein The cross-section of the air chamber is square; the bottom surface of the horizontal section below the vertical section is an inclined plane; the air distribution plate is composed of a perforated plate and air caps; a plurality of air cap insertion holes are formed in the perforated plate, and the air caps are fixedly arranged in the air cap insertion holes in a one-to-one correspondence; the air cap is composed of a cap top and a cap neck, and a plurality of small holes with a diameter of 6-8 mm are formed in the cap neck along the circumferential direction, and the ratio of the total area of the small holes to the top area of the perforated plate, that is, the air cap opening ratio, is 2.2%-2.8%; the hole pitch 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 20 mm; one ash discharge hole is arranged within every 1.3-1.5 m 2 on the air distribution plate.

3. A sludge incinerator according to claim 1, characterized in that, The reduced-diameter section is a conical structure with a round top and a square bottom, and the angle between the furnace wall of the reduced-diameter section and the horizontal plane is not less than 60°; a heat-insulating layer is arranged on the inner side of the furnace wall of the reduced-diameter section, and the slag overflow port is arranged at a height of 0.5 - 1.5 m from the bottom surface of the reduced-diameter section.

4. A sludge incinerator according to claim 1, characterized in that, A heat-insulating layer is arranged on the inner side of the furnace wall of the ascending section; there are 8 auxiliary burners, which are evenly distributed along the circumferential direction; there are 8 furnace thermometers, which are arranged in one-to-one correspondence with the auxiliary burners below; the ventilation and flow-guiding grille consists of a plurality of ventilation beams arranged in a vertical and horizontal cross pattern.

5. A sludge incinerator according to claim 1, characterized in that, A heat-insulating layer is arranged on the inner side of the furnace wall of the quick-drying section; there are 4 groups of sludge atomizing spray guns and cooling water spray guns respectively; the vertical spraying opening angles of the sludge atomizing spray gun and the cooling water spray gun are both 45°, and the horizontal spraying opening angles are both 135°.

6. The sludge incinerator according to claim 1, characterized in that, A heat-insulating layer is arranged on the inner side of the furnace wall of the dust-removing section; the ceramic tube filter is provided with a compressed air back-blowing dust-removing device.

7. A working method of a sludge incinerator according to any one of claims 1 to 6, characterized in that, It includes the following process: 1) After the ignition burner ignites and burns, the air is heated to above 850 °C, and the hot flue gas is evenly distributed into the furnace chamber through the wind-distributing plate; through a plurality of auxiliary burners arranged at the lower part of the furnace chamber, the temperature in the incinerator is maintained uniform. 2) The sludge is sprayed into the furnace chamber in the middle of the quick-drying section through the sludge atomizing spray gun, contacts and exchanges heat with the hot flue gas introduced from the ascending section, 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 contacts with the hot flue gas with a low flow rate to achieve suspension incineration, and is burned out during the process of falling to the ascending section and the reduced-diameter section; the burned ash and unburned particles with a large density fall into the slag pool for final incineration. 3) The water vapor separated 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, where they are intercepted by the ceramic tube filter, combine with the ash, gradually aggregate and grow larger, and are finally blown back into the furnace during the reverse blowing and dust cleaning process until they are completely 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 through the smoke collecting section.

8. The working method of a sludge incinerator according to claim 7, characterized in that, The inlet air velocity of the air chamber does not exceed 10 m / s; the air velocity at the small holes on the wind cap neck on the air distribution plate is 35 - 45 m / s; the hot flue gas velocity in the rising section is lower than 1 m / s; the temperature of the hot flue gas at the outlet of the rising section is not lower than 850 °C; the furnace pressure is maintained at -90 to -110 Pa; the target temperature of the flue gas at the outlet of the smoke collecting section is 120 °C.

9. The working method of a sludge incinerator according to claim 8, characterized in that, The temperature is measured by the outlet thermometer. When the outlet flue gas temperature is lower than 120 °C, the auxiliary burner is turned on for auxiliary heating; when the outlet flue gas temperature is higher than 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 increase, the sludge injection amount is increased; if the outlet flue gas temperature still rises and reaches 180 °C after taking the above measures, emergency cooling water is sprayed in through the cooling water spray gun to cool down.

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