Sewage sludge treatment method

Abstract

The present invention discloses a method for treating sewage sludge. The sewage sludge is fed into a sewage sludge treatment tank through a feeding port. During the treatment process, the feeding port and the discharging port are in a closed state. When the tank heating device 1 is started, it heats the sewage sludge treatment tank. The steam generated by heating the sewage sludge enters a distillation water tank along a steam pipeline through a vacuum pump. The dry powder formed after the sewage sludge is heated and dehydrated is used as fuel for combustion by the tank heating device 1. The present invention has the advantages of convenient sewage sludge treatment, energy conservation, low treatment cost, sanitation and environmental protection, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection equipment, and specifically relates to a method for treating sewage sludge. Background Art

[0002] Urban sewage treatment technology uses various facilities, equipment and process technologies to separate and remove the pollutants contained in the sewage discharged from urban sewage pipes from the water, convert harmful substances into harmless and useful substances, purify the water, and make full use of resources.

[0003] Urban sewage treatment is generally divided into three levels: primary treatment generally uses physical treatment technologies to filter out insoluble pollutants and parasite eggs in the sewage (such as sedimentation technology, filtration technology, air flotation technology, etc.), secondary treatment generally uses biological treatment technologies to oxidize and degrade various complex organic substances in the sewage (such as aerobic biological oxidation and anaerobic biological fermentation technologies), and tertiary treatment generally uses chemical treatment technologies, physicochemical technologies, etc. to remove refractory organic substances, inorganic salts, etc. in the sewage (such as neutralization, dosing coagulation, ion exchange, etc.);

[0004] The sludge filtered out during the sewage treatment process needs to be treated separately.

[0005] The deficiencies of the above sewage treatment methods are as follows: organic substances in the sewage can only be removed through multi-stage treatment, and the sludge also needs to be treated by separate treatment equipment, resulting in high treatment costs and long treatment times. With the development and progress of cities, the sewage discharge increases year by year, and the treatment load of urban sewage treatment plants is large, further increasing the cost and cycle of sewage treatment. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for treating sewage sludge that is convenient for sewage sludge treatment, energy-saving, odorless during the treatment process, low in treatment cost, and hygienic and environmentally friendly.

[0007] The technical solution adopted by the present invention to solve its technical problems is:

[0008] A method for treating sewage sludge, characterized in that the treatment method is:

[0009] The sewage sludge is fed into the sewage sludge treatment tank from the feeding port;

[0010] During the treatment process, the feeding port and the discharging port are in a closed state, and the tank heating device 1 is started to heat the sewage sludge treatment tank;

[0011] The steam generated by heating the sewage sludge enters the distillation water tank along the steam pipeline through the vacuum pump, and the dry powder formed after the sewage sludge is heated and dehydrated is used as fuel for combustion by the tank heating device 1;

[0012] The sewage and sludge discharged from urban sewage pipes can enter the sewage and sludge treatment tank together for treatment. The sewage vaporizes and is sterilized. After vaporization, the sewage enters the distillation water tank and can be recycled. The dry powder formed after the sludge is dehydrated can be recycled as fuel, eliminating the need for separate treatment of the sludge. Compared with the tertiary treatment of the original urban sewage, it has lower costs, is more convenient to treat, and saves energy.

[0013] This invention uses a sewage and sludge treatment device for treatment. The sewage and sludge treatment device includes a sewage and sludge treatment tank, a vacuum pump, a steam pipeline, and a first tank heating device. The sewage and sludge treatment tank is provided with a feeding port, a discharging port, and a steam outlet. One end of the steam pipeline is connected to the steam outlet, and the other end is connected to the distillation water tank. The sewage and sludge treatment tank is heated by the first tank heating device.

[0014] The sewage and sludge treatment tank of this invention includes a dehydration tank and a heat conduction interlayer. The dehydration tank is provided with a feeding port, a discharging port, and a steam outlet. The heat conduction interlayer is wrapped outside the dehydration tank, and a heat conduction medium is arranged in the heat conduction interlayer. The heat conduction medium is heated by the first tank heating device;

[0015] A heat conduction medium is arranged in the heat conduction interlayer, and the dehydration tank is heated through the heat conduction medium to realize the dehydration of the sludge in the dehydration tank to form dry powder.

[0016] The first tank heating device of this invention includes a hot water boiler, a first hot water circulation pump, a water inlet pipeline, and a water outlet pipeline. The heat conduction interlayer is provided with a water inlet and a water outlet. The hot water boiler is connected to the water inlet of the heat conduction interlayer through the water inlet pipeline and to the water outlet of the heat conduction interlayer through the water outlet pipeline. The first hot water circulation pump is connected to the water inlet pipeline or the water outlet pipeline;

[0017] The heat conduction medium of the hot water boiler enters the heat conduction interlayer to heat the dehydration tank. It can not only sterilize the sludge and sewage in the dehydration tank, but also vaporize the sewage for easy recovery, and can also dry the sludge. The dried sludge is used as the fuel of the hot water boiler, enabling the full and effective recycling of energy, saving costs, being hygienic and environmentally friendly, with a simple sewage and sludge treatment process and high treatment efficiency.

[0018] The steam generated by heating the sewage and sludge in this invention enters the steam pipeline from the steam outlet, first passes through the flue of the hot water boiler, and then enters the distillation water tank after the steam is pyrolyzed by the high-temperature flue gas in the flue;

[0019] The steam in the steam pipeline is heated by the high-temperature flue gas of the hot water boiler to realize steam pyrolysis. The organic matters and pollutants such as COD, BOD, and ammonia nitrogen in the steam are removed through high temperature, further enabling the drained water to meet the standards, without causing environmental pollution, and also realizing the utilization of waste heat.

[0020] The steam pipeline described in the present invention forms a serpentine pipeline in the flue of the hot water boiler; the steam evaporated from the dehydration tank enters the steam pipeline and flows along the serpentine pipeline in the flue. The serpentine pipeline is arranged to enable the steam to maintain a sufficiently long residence time in the flue, and under the action of high temperature, the organic matter in the steam can be decomposed better.

[0021] The high-temperature steam in the steam pipeline described in the present invention comes out of the flue, is condensed by the steam condensation device, and then enters the distillation water tank; the high-temperature steam is condensed and liquefied.

[0022] The steam condensation device described in the present invention includes a heat exchanger, a cooling tower, a cooling water pump and a first circulation pipeline. One end of the first circulation pipeline is communicated with the water inlet of the cooling tower, and the other end is communicated with the water outlet of the cooling tower. The first circulation pipeline exchanges heat with the steam pipeline through the heat exchanger, and the first circulation pipeline is connected to the cooling water pump;

[0023] The steam generated by heating the sewage sludge enters the steam pipeline from the steam outlet. First, it passes through the flue of the hot water boiler, and the high-temperature flue gas in the flue pyrolyzes the steam. Then, it passes through the heat exchanger, and the cooling water in the first circulation pipeline cools the high-temperature steam in the steam pipeline to realize steam condensation and then flow into the distillation water tank.

[0024] The steam condensation device described in the present invention includes an evaporator, a compressor, a condenser, an expansion valve and a second circulation pipeline. The second circulation pipeline sequentially passes through the evaporator, the compressor, the condenser and the expansion valve. The second circulation pipeline exchanges heat with the steam pipeline through the evaporator;

[0025] The compressor starts, and the refrigerant circulates in the second circulation pipeline. The steam generated by heating the sewage sludge enters the steam pipeline from the steam outlet. First, it passes through the flue of the hot water boiler, and the high-temperature flue gas in the flue pyrolyzes the steam. Then, it passes through the evaporator, and the evaporator absorbs the heat of the high-temperature steam in the steam pipeline to cool the high-temperature steam in the steam pipeline to realize steam condensation and then flow into the distillation water tank.

[0026] The sewage sludge treatment tank described in the present invention has at least two. The two sewage sludge treatment tanks are heated by the same first tank heating device, or the two sewage sludge treatment tanks are respectively heated by the first tank heating device, or one of the sewage sludge treatment tanks is heated by the first tank heating device, and the other sewage sludge treatment tank is heated by the second tank heating device.

[0027] The beneficial effects of the present invention are as follows: The sewage and sludge discharged from the urban sewage pipeline can enter the sewage sludge treatment tank together for treatment. The sewage is vaporized and sterilized. After the sewage is vaporized, it enters the distillation water tank and can be recycled. The dry powder formed after the sludge is dehydrated can be recycled as fuel, and there is no need to treat the sludge separately. Compared with the original tertiary treatment of urban sewage, the cost is low, the treatment is convenient, and energy is saved. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1.

[0029] Figure 2 It is a schematic diagram of the overall structure of Embodiment 2.

[0030] Figure 3 It is a schematic diagram of the steam pyrolysis structure in Embodiment 1 and Embodiment 2.

[0031] Reference numerals: temporary storage area - 1;

[0032] dehydration tank 1 - 201, feeding port 1 - 2011, discharging port 1 - 2012, heat conduction interlayer 1 - 202, dehydration tank 2 - 203, feeding port 2 - 2031, discharging port 2 - 2032, heat conduction interlayer 2 - 204;

[0033] filter 1 - 301, heat exchanger 1 - 302, vacuum pump 1 - 303, distillation water tank 1 - 304, discharge valve 1 - 305, check valve 1 - 306, filter 2 - 307, cooling tower - 308, cooling water pump - 309, steam pipeline 1 - 310, circulation pipeline 1 - 311, heat exchanger 2 - 312;

[0034] filter 3 - 401, evaporator - 402, vacuum pump 2 - 403, distillation water tank 2 - 404, discharge valve 2 - 405, check valve 2 - 406, circulation pipeline 2 - 407, compressor - 408, expansion valve - 409, steam pipeline 2 - 410;

[0035] hot water boiler - 501, furnace - 5011, water circulation interlayer - 5012, flue - 5013, filter 4 - 502, hot water circulation pump 1 - 503, expansion water tank 1 - 504, water inlet pipeline - 505, water outlet pipeline - 506;

[0036] hot water circulation pump 2 - 601, filter 5 - 602, expansion water tank 2 - 603, heat conduction pipeline - 604, condenser - 605;

[0037] dry powder slag stacking area - 7;

[0038] discharge channel 1 - 801, discharge channel 2 - 802;

[0039] snake - shaped pipeline - 9;

[0040] feeding channel 1 - 1001, feeding channel 2 - 1002. Detailed implementation manners

[0041] The present invention will be described below with reference to the accompanying drawings and embodiments.

[0042] Embodiment 1 (as shown in the attachedFigure 1 , attached Figure 3 as shown in

[0043] Example 1 shows the structure of a sewage sludge treatment device including a sewage sludge treatment tank. A sewage sludge treatment device includes a first sewage sludge treatment tank, a first vacuum pump 303, a first steam pipeline 310, and a first tank heating device. The first sewage sludge treatment tank is provided with a first feeding port 2011, a first discharging port 2012, and a first steam outlet. One end of the first steam pipeline 310 is communicated with the first steam outlet, and the other end is communicated with a first distillation water tank 304. The first steam pipeline 310 is connected to the first vacuum pump 303, and the first vacuum pump is connected to a controller;

[0044] The first tank heating device heats the first sewage sludge treatment tank and uses the dry powder after dehydration treatment in the first sewage sludge treatment tank as fuel;

[0045] When the first tank heating device works, the first feeding port 2011 and the first discharging port 2012 are in a closed state;

[0046] The sewage and sludge discharged from the urban sewage pipeline can enter the first sewage sludge treatment tank together for treatment. The sewage vaporizes and is sterilized. After the sewage vaporizes, it enters the first distillation water tank and can be recycled. The dry powder formed after the sludge is dehydrated can be recycled as fuel, and there is no need to treat the sludge separately. Compared with the original tertiary treatment of urban sewage, the cost is low, the treatment is convenient, and energy is saved; the setting of the first vacuum pump 303 facilitates the timely extraction of steam in the first sewage sludge treatment tank, improves work efficiency, realizes the rapid treatment of sewage sludge, has a low cost, and at the same time, the negative pressure of the first vacuum pump also makes the water in the sewage sludge treatment tank easier to vaporize, and the vacuum environment can also kill some germs.

[0047] During this process, some bacteria are killed by the vacuum environment, and some bacteria are killed by high temperature in the first dehydration tank.

[0048] The first sewage sludge treatment tank includes a first dehydration tank 201 and a first heat conduction interlayer 202. The first dehydration tank 201 is provided with a first feeding port 2011, a first discharging port 2012, and a first steam outlet. The first heat conduction interlayer 202 is wrapped outside the first dehydration tank 201. A heat conduction medium is arranged in the first heat conduction interlayer 202, and the heat conduction medium is heated by the first tank heating device; a heat conduction medium is arranged in the first heat conduction interlayer, and the dehydration tank is heated by the high temperature of the heat conduction medium and the high-temperature steam generated by the heat conduction medium to realize the dehydration of the sludge in the dehydration tank to form dry powder.

[0049] In this embodiment, the heat conduction medium adopts a mixture of distilled water + antifreeze, and the heat conduction medium is selected according to actual use needs.

[0050] In this embodiment, a heat-conducting outer wall is arranged outside the first dehydration tank 201. The heat-conducting outer wall surrounds the outer wall of the first dehydration tank. The upper part of the heat-conducting outer wall is fixedly connected to the outer wall of the first dehydration tank through a heat-conducting upper wall, and the lower part is fixedly connected to the outer wall of the first dehydration tank through a heat-conducting lower wall. A sealed first heat-conducting interlayer is formed between the heat-conducting outer wall and the outer wall of the first dehydration tank, as well as between the heat-conducting upper wall and the heat-conducting lower wall. This is only one way of arranging the first heat-conducting interlayer. A heat-conducting groove can also be arranged so that the first dehydration tank is inserted into the heat-conducting groove, and the upper part of the heat-conducting groove is hermetically connected to the outer wall of the first dehydration tank to form the first heat-conducting interlayer.

[0051] The first tank heating device includes a hot water boiler 501, a first hot water circulation pump 503, a fourth filter 502, an expansion tank 504, a water inlet pipe 505 and a water outlet pipe 506. The first heat-conducting interlayer 202 is provided with a water inlet and a water outlet. The hot water boiler 501 is connected to the water inlet of the first heat-conducting interlayer 202 through the water inlet pipe 505 and to the water outlet of the first heat-conducting interlayer 202 through the water outlet pipe 506. The hot water boiler 501 uses the dry powder in the first dehydration tank 201 as fuel. The first hot water circulation pump 503 is connected to the water inlet pipe 505 or the water outlet pipe 506, and the first hot water circulation pump is connected to the controller.

[0052] In this embodiment, the first hot water circulation pump 503 is connected to the water inlet pipe 505. A fourth filter 502 is installed on the water inlet pipe 505 between the hot water boiler 501 and the first hot water circulation pump 503. The expansion tank is arranged on the water outlet pipe 506. The expansion tank is used to accommodate the expansion amount of water and also plays a role in constant pressure and water replenishment.

[0053] The hot water in the hot water boiler 501 enters the first heat-conducting interlayer 202 under the action of the first hot water circulation pump 503 to heat the first dehydration tank 201, which can not only sterilize the sludge and sewage in the first dehydration tank 201, but also vaporize the sewage for recovery, and can also dry the sludge. The dried sludge is used as the fuel of the hot water boiler 201, so that the energy can be fully and effectively recycled, the cost is saved, the sanitation and environmental protection are achieved, the sewage and sludge treatment process is simple, and the treatment efficiency is high.

[0054] In this embodiment, the hot water boiler 501 includes a furnace 5011, a water circulation interlayer 5012 and a flue 5013. The water circulation interlayer 5012 is wrapped outside the furnace 5011. The water inlet pipe 505 is communicated with the water outlet of the water circulation interlayer 5012, and the water outlet pipe 506 is communicated with the water inlet of the water circulation interlayer 5012. A fourth filter 502 and a first hot water circulation pump 503 are installed on the water inlet pipe 505. The flue 5013 is arranged at the upper end of the furnace 5011 and is communicated with the furnace 5011. The dry powder burns in the furnace 5011 to heat the water circulation interlayer 5012, and the flue gas generated by the combustion goes out from the flue 5013.

[0055] The first steam pipeline 310 first passes through the flue 5013 of the hot water boiler 501 and then passes through the steam condensation device and extends into the first distillation water tank 304; the high temperature of the flue 5013 of the hot water boiler is used to heat the steam in the first steam pipeline 310 to achieve pyrolysis, and organic matters and pollutants such as COD, BOD, and ammonia nitrogen in the steam are removed through high temperature, further enabling the drained water to meet the standards, not causing environmental pollution, and realizing the utilization of waste heat.

[0056] The first steam pipeline 310 forms a serpentine pipeline 9 in the flue 5013 of the hot water boiler; the steam evaporated from the first dehydration tank 201 enters the first steam pipeline 310 and then flows along the serpentine pipeline 9 in the flue 5013. The serpentine pipeline 9 is arranged to make the flow time of the steam in the flue 5013 long, and the organic matters in the steam are better pyrolyzed under the action of high temperature.

[0057] In this embodiment, the first steam pipeline 310 exchanges heat through the second heat exchanger 312 before entering the flue 5013. The steam in the first dehydration tank 201 passes through the first steam pipeline 310 to reach the second heat exchanger 312, then passes through the serpentine pipeline 9, and then passes through the second heat exchanger 312 again and is condensed by the steam condensation device; the function of the second heat exchanger 312 is that the steam coming out of the first dehydration tank 201 in the first steam pipeline 310 has a relatively low temperature, and the steam in the first steam pipeline 310 after passing through the serpentine pipeline 9 has a relatively high temperature. The high-temperature steam in the first steam pipeline 310 is used to preheat the low-temperature steam in the first steam pipeline 310, further ensuring the steam pyrolysis effect, and at the same time enabling the high-temperature steam to cool down, further ensuring the condensation effect.

[0058] In this embodiment, the steam condensation device includes a first heat exchanger 302, a cooling tower 308, a cooling water pump 309, and a first circulation pipeline 311. One end of the first circulation pipeline 311 is communicated with the water inlet of the cooling tower 308, and the other end is communicated with the water outlet of the cooling tower 308. The first circulation pipeline 311 exchanges heat with the first steam pipeline 310 through the first heat exchanger 302. The first circulation pipeline 311 is connected to the cooling water pump 309, and the cooling water pump is connected to the controller; the cold water in the cooling tower 308 exchanges heat with the steam in the first steam pipeline 310 under the action of the cooling water pump 309 to realize the condensation of the steam in the first steam pipeline 310.

[0059] The structure of the cooling tower 308 is a prior art and will not be described in detail here.

[0060] The structure of the steam condensation device is not limited to this. Using an evaporator, a condenser, etc. to realize the cooling of the steam in the first steam pipeline is sufficient.

[0061] In this embodiment, a second filter 307 is installed on the first circulation pipeline. The cooling water coming out of the cooling tower outlet first passes through the second filter 307 and then enters the first heat exchanger 302 through the cooling water pump 309 for heat exchange.

[0062] In this embodiment, a first filter 301 is installed on the first steam pipeline 310. The steam in the first dehydration tank 201 first passes through the first filter 301 for filtration and then undergoes high-temperature pyrolysis and heat exchange in the heat exchanger, and then enters the first distillation water tank 304 through the first vacuum pump 303. A first discharge valve 305 is installed on the first distillation water tank. When the water in the first distillation water tank accumulates to a certain amount, the first discharge valve 305 is opened for discharge. The first discharge valve 305 can be a manual valve or an electric valve. When the first discharge valve 305 is an electric valve, the first discharge valve 305 is connected to the controller.

[0063] In this embodiment, a first one-way valve 306 is installed on the first steam pipeline. The first one-way valve 306 is arranged between the first heat exchanger and the first vacuum pump to prevent the steam from condensing and flowing back.

[0064] In this embodiment, the first feeding port is communicated with the first feeding channel 1001. A first control valve is installed on the first feeding channel 1001. The first control valve can be manual or electric. When the first control valve is electric, the first control valve is connected to the controller. In this embodiment, the first feeding port 2011 is sealed through the first control valve, and the first discharge port 2012 is covered with a discharge port cover.

[0065] In this embodiment, a dry powder stacking area is provided near the hot water boiler. The dry powder is conveyed from the first discharge port to the dry powder stacking area through a conveying device, and then enters the furnace of the hot water boiler from the dry powder stacking area. In this embodiment, the conveying device is driven by a motor to convey a conveyor belt. The conveyor belt structure is a prior art and will not be described in detail here.

[0066] In this embodiment, a temperature sensor is provided for detecting the temperature of the first heat conduction layer. In this embodiment, the temperature sensor uses a thermal resistance sensor. A first thermal resistance sensor and a second thermal resistance sensor are installed on the first heat conduction layer. The first thermal resistance sensor and the second thermal resistance sensor are respectively connected to the controller. By setting the first thermal resistance sensor and the second thermal resistance sensor, the temperature inside the first heat conduction layer is detected to prevent the temperature inside the first heat conduction layer from being too high.

[0067] This embodiment is provided with a pressure transmitter for detecting the pressure of the first dehydration tank. The pressure transmitter is installed on the first dehydration tank and is connected to the controller. By setting the pressure transmitter to detect the pressure of the first dehydration tank, it is ensured that the inside of the tank is maintained at a certain vacuum degree. Through the monitoring of the vacuum, it can be fed back whether the performance of the first vacuum pump is normal, whether the first filter is blocked, the drying condition of the material, etc. When the negative pressure value in the first dehydration tank is higher than the set value, the equipment is controlled to stop working through the controller, and the equipment is overhauled to check whether there are blockages in the first filter, pipeline, etc. or whether there is damage to the first vacuum pump, etc.

[0068] This embodiment is provided with a safety valve, and the safety valve is installed on the first heat conduction interlayer. The safety valve plays a protective role. When the pressure in the first heat conduction interlayer is too high, the safety valve automatically opens to release the pressure in the first heat conduction interlayer, avoiding too high pressure in the first heat conduction interlayer and ensuring the safety of the equipment. In this embodiment, the safety valve adopts a spring-type safety valve, but it is not limited to this, and a lever-type safety valve, etc. can also be adopted.

[0069] In this embodiment, the controller can adopt a PLC controller or a controller developed based on an MCU.

[0070] The sewage sludge dehydration treatment method in Embodiment 1 is as follows:

[0071] 1. The sewage and sludge discharged from the urban sewage pipeline enter the temporary storage area 1. The first control valve is opened, and the sewage and sludge enter the first dehydration tank 201 through the feeding channel 1001 and the first feeding port 2011. The first control valve is closed, and during this process, the outlet cover is in a closed state.

[0072] 2. Dry powder that has been dehydrated is placed in the furnace 5011 of the hot water boiler 501, and the dry powder is ignited and burned. The heat conduction medium in the water circulation interlayer 5012 is heated by the high temperature of the furnace. The controller controls the first hot water circulation pump 503 to work. The heated heat conduction medium is filtered by the fourth filter 502 and then transported from the water inlet of the first heat conduction interlayer to the first heat conduction interlayer 202 through the water inlet pipeline 505. The heat conduction medium in the first heat conduction interlayer 202 returns to the water circulation interlayer 5012 from the water outlet pipeline 506 through the water outlet of the first heat conduction interlayer. The incoming heat conduction medium is heated by the high temperature of the water circulation interlayer, and the first dehydration tank is heated by the high temperature of the heat conduction medium.

[0073] 3. The controller controls the operation of vacuum pump 1 (303), creating a negative pressure in dewatering tank 1 (201). The heat-conducting medium heats dewatering tank 1 (201), causing the sludge to dehydrate and form steam. The steam in dewatering tank 1 (201) first passes through filter 1 (301), then successively through heat exchanger 2 (312), flue 5013, heat exchanger 2 (312), heat exchanger 1 (302), check valve 1 (306), and vacuum pump 1 (303) before flowing into distillation water tank 1 (304). The steam in dewatering tank 1 (201) is relatively low in temperature (low-temperature steam) before entering flue 5013 and relatively high in temperature (high-temperature steam) after passing through flue 5013. The low-temperature steam in steam pipeline 1 first increases in temperature after heat exchange with high-temperature steam and then enters flue 5013, further ensuring the steam pyrolysis effect. The high-temperature steam coming out of flue 5013 in steam pipeline 1 first decreases in temperature after heat exchange with low-temperature steam and then exchanges heat and condenses with circulation pipeline 1 (311).

[0074] 4. After the sewage in dewatering tank 1 (201) evaporates, the dried sludge forms dry powder. Open the discharge port cover, convey the dry powder to the dry powder slag stacking area 7 through the conveying device, and then add the dry powder into the furnace chamber 5011 of the hot water boiler as fuel for combustion.

[0075] 5. The slag after combustion is collected in the dry powder slag stacking area 7, and the slag can be used for brick making.

[0076] 6. During the sewage sludge dewatering process, thermal resistance sensor 1 and thermal resistance sensor 2 detect the temperature of heat-conducting layer 1 and feedback the signal to the controller. When the temperature in heat-conducting layer 1 reaches the set value, reduce the fuel supply in the hot water boiler (manually or the controller controls the automatic feeder to reduce the fuel addition) to reduce the heat supply. When the temperature of the heat-conducting layer is lower than the set value, increase the fuel supply in the hot water boiler (manually or the controller controls the automatic feeder to increase the fuel) to increase the heat supply. The pressure transmitter detects the steam pressure in dewatering tank 1 and feedbacks the signal to the controller to ensure that the inside of the tank is maintained at a certain vacuum degree. Through the monitoring of the vacuum, it can be reflected whether the performance of vacuum pump 1 is normal, whether filter 1 is blocked, the material drying situation, etc. When the pressure in heat-conducting layer 1 exceeds a certain value, the safety valve automatically opens to discharge the steam, ensuring the safety of the equipment.

[0077] This sewage sludge treatment device realizes the primary, secondary, and tertiary treatment of the original sewage treatment plant as well as the re-treatment of sludge. It has a simple structure, can replace the original sewage treatment mode, treats sewage and sludge simultaneously, and there is no need to separately treat the filtered sludge. The distilled water in the distillation water tank meets the discharge standard and can be reused. The slag after sludge combustion can be used for brick making, and the energy is greatly recycled. This sewage sludge treatment device can also be used as the primary or secondary or tertiary treatment device of the sewage treatment plant according to actual usage needs.

[0078] Example 2 (as shown in the appendixFigure 2 as shown

[0079] Example 2 is based on Example 1 with an additional sewage sludge treatment tank 2. The structure of the sewage sludge treatment tank 2 is the same as that of the sewage sludge treatment tank 1. The sewage sludge treatment tank 2 includes a dehydration tank 203 and a heat conduction interlayer 204. The dehydration tank 203 is provided with a feeding port 2031, a discharging port 2032 and a steam outlet 2. The heat conduction interlayer 204 is wrapped outside the dehydration tank 203, and a heat conduction medium is arranged in the heat conduction interlayer 204. When the sewage in the dehydration tank is heated, the feeding port 2031 and the discharging port 2032 are in a closed state;

[0080] One end of the steam pipeline 2 410 is communicated with the steam outlet 2, and the other end is communicated with the distillation water tank 2 404. The steam pipeline 2 410 is connected to a vacuum pump 2 403, and the vacuum pump 2 403 is connected to a controller; The setting of the vacuum pump 2 403 facilitates timely extraction of the steam in the sewage sludge treatment tank 2, improves work efficiency, realizes rapid treatment of sewage sludge, has low cost, and at the same time, the negative pressure of the vacuum pump 2 403 also makes the water in the sewage sludge treatment tank easier to vaporize, and the vacuum environment is convenient for sterilization.

[0081] In this embodiment, the heat conduction medium is a mixture of distilled water + antifreeze, and the heat conduction medium is selected according to actual use needs.

[0082] In this embodiment, an evaporator 402, a compressor 408, an expansion valve 409, a second circulation pipeline 407, a second hot water circulation pump 601, a fifth filter 602, an expansion tank 603, a condenser 605 and a heat conduction pipeline 604 are provided. The second circulation pipeline 407 exchanges heat with a second steam pipeline 410 through the evaporator 402. The second circulation pipeline sequentially passes through the evaporator, the compressor, the condenser, and the expansion valve to form a closed loop. The compressor 408 is arranged at the air outlet end of the evaporator 402 and is connected to a controller. The expansion valve 409 is arranged at the air inlet end of the evaporator 402. The condenser 605 is arranged between the expansion valve 409 and the compressor 408. The second circulation pipeline 407 exchanges heat with the heat conduction pipeline 604 through the condenser 605. One end of the heat conduction pipeline 604 is communicated with the water outlet of a second heat conduction layer 204, and the other end is communicated with the water inlet of the second heat conduction layer 204. An expansion tank 603 is provided on the heat conduction pipeline 604 between the water outlet of the second heat conduction layer 204 and the condenser 605. A fifth filter 602 and a second hot water circulation pump 601 are installed between the condenser 605 and the second heat conduction layer 204. The steam in the second steam pipeline 410 is condensed by absorbing heat from the second steam pipeline 410 through the evaporator 402. The condenser 605 releases heat outward to increase the temperature of the heat conduction medium in the heat conduction pipeline 604 (the second tank heating device in the specification). The heat conduction medium in the second heat conduction layer 204 flows out from the water outlet of the second heat conduction layer 204, is first heated up by the condenser 605 in the heat conduction pipeline 604, and then flows into the second heat conduction layer 204 from the water inlet of the second heat conduction layer 204 through the fifth filter 602 and the second hot water circulation pump 601.

[0083] In this embodiment, the steam evaporated from the second dehydration tank 203 enters the second steam pipeline 410, first passes through the flue 5013 of the hot water boiler 501, and then passes through the evaporator and extends into the second distillation tank 404. The high temperature of the flue 5013 of the hot water boiler is used to heat the steam in the second steam pipeline 410 to achieve steam pyrolysis. Organic substances and pollutants such as COD, BOD, and ammonia nitrogen in the steam are removed through high temperature, further enabling the drained water to meet the standards, without causing environmental pollution, and also realizing the utilization of waste heat.

[0084] In this embodiment, the structure for high-temperature steam pyrolysis is the same as that in Embodiment 1 (same as the appendix Figure 3 ) and will not be elaborated in detail here.

[0085] In this embodiment, a third filter 401 is installed on the second steam pipeline 410. The steam in the second dehydration tank 203 is first filtered by the third filter 401, then undergoes high-temperature pyrolysis and heat exchange in the evaporator, and then enters the second distillation water tank 404 through the second vacuum pump 403. A second discharge valve 405 is installed on the second distillation water tank 404. When the water in the second distillation water tank accumulates to a certain amount, the second discharge valve 405 is opened for discharging. The second discharge valve 405 can be a manual valve or an electric valve. When the first discharge valve 405 is an electric valve, the first discharge valve 405 is connected to the controller.

[0086] In this embodiment, a second check valve 406 is installed on the second steam pipeline. The second check valve 406 is arranged between the evaporator 402 and the second vacuum pump 403 to prevent the steam from condensing and flowing back.

[0087] In this embodiment, the second feeding port is communicated with the second feeding channel 1002. A second control valve is installed on the second feeding channel 1002. The first control valve can be manual or electric. When the second control valve is electric, the second control valve is connected to the controller. In this embodiment, the second feeding port 2031 is sealed through the second control valve, and the second discharge port 2032 is covered with a discharge port cover. The dry powder is conveyed from the second discharge port to the dry powder stacking area through the conveying device to provide fuel for the hot water boiler in Embodiment 1.

[0088] In this embodiment, a temperature sensor and a safety valve are also provided on the second heat conduction layer, and a pressure transmitter is provided on the first dehydration tank.

[0089] The sewage and sludge treatment method of Embodiment 2 is as follows:

[0090] 1. The sewage and sludge discharged from the urban sewage pipeline enter the temporary storage area 1. The first control valve and the second control valve are opened. The sewage and sludge enter the first dehydration tank 201 through the first feeding port 2011 along the first feeding channel 1001, and enter the second dehydration tank 203 through the second feeding port 2031 along the second feeding channel 1002. The first control valve and the second control valve are closed. During this process, the discharge port covers at the first discharge port and the second discharge port are in the closed state;

[0091] 2. The dehydrated dry powder is placed in the furnace 5011 of the hot water boiler 501. The dry powder is ignited and burned, and the heat conduction medium in the water circulation layer 5012 is heated by the high temperature in the furnace. The controller controls the first hot water circulation pump 503 to work. The heated heat conduction medium is filtered by the fourth filter 502 and then transported to the second heat conduction layer 202 through the water inlet pipe 505 from the water inlet of the first heat conduction layer. The heat conduction medium in the second heat conduction layer 202 returns to the water circulation layer 5012 through the water outlet pipe 506 from the water outlet of the first heat conduction layer. The incoming heat conduction medium is heated by the high temperature of the water circulation layer, and the first dehydration tank is heated by the high temperature of the heat conduction medium;

[0092] The controller controls the operation of the second hot water circulation pump 601 and the compressor 408. The high temperature in the second circulation pipeline 407 releases heat through the condenser 605, increasing the temperature in the heat conduction pipeline 604. The heat conduction medium in the heat conduction pipeline 604 enters the second heat conduction layer 204 from the water inlet of the second heat conduction layer 204 after being filtered by the fifth filter 602 under the action of the second hot water circulation pump 601, realizing the heating of the second dehydration tank 203. It then exits from the water outlet of the second heat conduction layer, passes through the heat conduction pipeline, and after passing through the condenser, releases heat to the outside again to heat the heat conduction medium in the heat conduction pipeline;

[0093] 3. The controller controls the operation of the first vacuum pump 303 to create a negative pressure in the first dehydration tank 201. The heat conduction medium heats the first dehydration tank 201, causing the sludge to dehydrate and form water vapor. The steam in the first dehydration tank 201 first passes through the first filter 301 and then successively through the second heat exchanger 312, the flue 5013, the second heat exchanger 312, the first heat exchanger 302, the first check valve 306, and the first vacuum pump 303 before flowing into the first distillation water tank 304. The steam in the first dehydration tank 201 is relatively low in temperature before entering the flue 5013 and is low-temperature steam, and relatively high in temperature after passing through the flue 5013 and is high-temperature steam. The low-temperature steam in the first steam pipeline first increases in temperature after heat exchange with the high-temperature steam and then enters the flue 5013 to further ensure the steam pyrolysis effect. The high-temperature steam coming out of the flue 5013 in the first steam pipeline first decreases in temperature after heat exchange with the low-temperature steam and then exchanges heat and condenses with the first circulation pipeline 311;

[0094] The controller controls the operation of the second vacuum pump 403 to create a negative pressure in the second dehydration tank 203. The heat conduction medium heats the second dehydration tank 203, causing the sludge to dehydrate and form water vapor. The steam in the second dehydration tank 203 first passes through the third filter 401 and then successively through the heat exchanger (with the same heat exchanger structure as Figure 3 ), the flue 5013, the heat exchanger (with the same heat exchanger structure as Figure 3 ), the evaporator 402, the second check valve 406, and the second vacuum pump 403 before flowing into the second distillation water tank 404. The steam in the second dehydration tank 203 is relatively low in temperature before entering the flue 5013 and is low-temperature steam, and relatively high in temperature after passing through the flue 5013 and is high-temperature steam. The low-temperature steam in the second steam pipeline first increases in temperature after heat exchange with the high-temperature steam and then enters the flue 5013 to further ensure the steam pyrolysis effect. The high-temperature steam coming out of the flue 5013 in the second steam pipeline first decreases in temperature after heat exchange with the low-temperature steam and then exchanges heat and condenses with the second circulation pipeline 407;

[0095] 4. After the sewage in the first dehydration tank 201 evaporates, the dried sludge forms dry powder. Open the discharge port cover at the first discharge port, convey the dry powder to the dry powder furnace slag stacking area 7 through the conveying device, and then add the dry powder into the furnace chamber 5011 of the hot water boiler as fuel for combustion;

[0096] After the sewage in the dehydration tank 203 evaporates, the dried sludge forms dry powder. Open the discharge port cover at the second discharge port, and convey the dry powder to the dry powder slag stacking area 7 through the conveying device. Then add the dry powder into the furnace chamber 5011 of the hot water boiler as fuel for combustion;

[0097] 5. The slag after combustion is collected in the dry powder slag stacking area 7, and the slag can be used for making bricks;

[0098] 6. During the sewage sludge dehydration treatment process, the first thermal resistance sensor and the second thermal resistance sensor detect the temperature of the first heat conduction interlayer and feedback the signal to the controller. When the temperature in the first heat conduction interlayer reaches the set value, reduce the fuel supply in the hot water boiler (manually or the controller controls the automatic feeder to reduce the fuel addition) to reduce the heat supply. When the temperature of the heat conduction interlayer is lower than the set value, increase the fuel supply in the hot water boiler (manually or the controller controls the automatic feeder to increase the fuel) to increase the heat supply. The pressure transmitter detects the steam pressure in the first dehydration tank and feedbacks the signal to the controller to ensure that the inside of the tank is maintained at a certain vacuum degree. Through the monitoring of the vacuum, the performance of the first vacuum pump, whether the first filter is blocked, the material drying situation, etc. can be fed back. When the pressure in the first heat conduction interlayer exceeds a certain value, the safety valve automatically opens to discharge the steam to ensure the safety of the equipment;

[0099] The temperature sensor on the second heat conduction interlayer detects the temperature of the second heat conduction interlayer and feedbacks the signal to the controller. When the temperature in the second heat conduction interlayer reaches the set value, the controller controls the compressor to stop working. The pressure transmitter on the second dehydration tank detects the steam pressure in the second dehydration tank and feedbacks the signal to the controller to ensure that the inside of the tank is maintained at a certain vacuum degree. Through the monitoring of the vacuum, the performance of the second vacuum pump, whether the third filter is blocked, the material drying situation, etc. can be fed back. When the pressure in the second heat conduction interlayer exceeds a certain value, the safety valve automatically opens to discharge the steam to ensure the safety of the equipment.

[0100] In Example 2, the dry powder in the second dehydration tank is also sent into the hot water boiler as fuel, and only the first dehydration tank is heated by the heating method of the hot water boiler.

[0101] Example 3:

[0102] In this example, it can be set that the two dehydration tanks are heated by the same first tank heating device, and the heat conduction pipeline communicated with the second heat conduction interlayer 204 is communicated with the water circulation interlayer 5012 of the hot water boiler 501. A second hot water circulation pump and a fifth filter are installed on the heat conduction pipeline, and the heat conduction medium in the water circulation interlayer 5012 can enter the first heat conduction interlayer 202 and the second heat conduction interlayer 204 at the same time.

[0103] Example 4:

[0104] In this embodiment, two hot water boilers can be set up. Each dehydration tank is heated through a hot water boiler, and the dried dry powder in each dehydration tank serves as the fuel for its respective hot water boiler.

Claims

1. A sewage sludge treatment method, characterized in that there are provided a sewage sludge treatment tank, a vacuum pump, a steam pipeline and a first tank heating device. The sewage sludge treatment tank includes a dehydration tank and a heat conduction interlayer. The dehydration tank is provided with a feeding port, a discharging port and a steam outlet. The heat conduction interlayer is wrapped outside the dehydration tank. The heat conduction interlayer is provided with a water inlet and a water outlet. A heat conduction medium is arranged in the heat conduction interlayer. One end of the steam pipeline is communicated with the steam outlet, and the other end is communicated with a distillation water tank; the first tank heating device includes a hot water boiler, a hot water circulation pump, a water inlet pipeline and a water outlet pipeline. The hot water boiler includes a furnace chamber, a water circulation interlayer and a flue. The water circulation interlayer is wrapped outside the furnace chamber. The water inlet pipeline is communicated with the water outlet of the water circulation interlayer, and the water outlet pipeline is communicated with the water inlet of the water circulation interlayer. The hot water circulation pump is connected to the water inlet pipeline or the water outlet pipeline. The flue is arranged at the upper end of the furnace chamber and is communicated with the furnace chamber; a temperature sensor is arranged on the heat conduction interlayer; a pressure transmitter is arranged on the dehydration tank; the treatment method is as follows: the sewage and sludge discharged from the sewage discharge pipeline enter the temporary storage area. The control valve is opened, and the sewage and sludge enter the dehydration tank through the feeding port along the feeding channel. The control valve is closed, and during this process, the discharging port cover is in a closed state; dry powder that has been dehydrated is placed in the furnace chamber of the hot water boiler. The dry powder is ignited and burned. The heat conduction medium in the water circulation interlayer is heated by the high temperature of the furnace chamber. The controller controls the hot water circulation pump to work. The heated heat conduction medium is transported to the heat conduction interlayer through the water inlet of the heat conduction interlayer by the water inlet pipeline. The heat conduction medium in the heat conduction interlayer returns to the water circulation interlayer from the water outlet of the heat conduction interlayer through the water outlet pipeline. The incoming heat conduction medium is heated by the high temperature of the water circulation interlayer. The dehydration tank is heated by the high temperature of the heat conduction medium; the controller controls the vacuum pump to work, so that a negative pressure is formed in the dehydration tank. The heat conduction medium heats the dehydration tank, so that the sludge is dehydrated to form steam. The steam in the dehydration tank successively passes through a second heat exchanger, a flue, a second heat exchanger, a first heat exchanger and a one-way valve and then flows into the distillation water tank. The steam in the dehydration tank has a relatively low temperature before entering the flue and is low-temperature steam, and has a relatively high temperature after passing through the flue and is high-temperature steam. The low-temperature steam in the steam pipeline is first heated by the high-temperature steam and then enters the flue after the temperature rises. The high-temperature steam coming out of the flue in the steam pipeline is cooled after being heat-exchanged with the low-temperature steam; after the sewage in the dehydration tank evaporates, the dried sludge forms dry powder, and the dry powder is added to the furnace chamber of the hot water boiler as fuel for combustion; during the sewage sludge dehydration treatment process, the temperature sensor detects the temperature of the heat conduction interlayer and feeds back the signal to the controller. When the temperature in the heat conduction interlayer reaches the set value, the fuel supply in the hot water boiler is reduced. When the temperature in the heat conduction interlayer is lower than the set value, the fuel supply in the hot water boiler is increased. The pressure transmitter detects the steam pressure in the dehydration tank and feeds back the signal to the controller. When the negative pressure value in the dehydration tank is higher than the set value, the equipment is controlled to stop working through the controller; 2. The sewage sludge treatment method according to claim 1, characterized in that: the steam pipeline forms a serpentine pipeline in the flue of the hot water boiler; 3. A sewage sludge treatment method according to claim 1 or 2, characterized in that: the high-temperature steam in the steam pipeline comes out of the flue, is condensed by a steam condensation device and then enters the distillation water tank.

4. A sewage sludge treatment method according to claim 3, wherein: The steam condensation device includes a heat exchanger, a cooling tower, a cooling water pump, and a first circulation pipeline. One end of the first circulation pipeline is communicated with the water inlet of the cooling tower, and the other end is communicated with the water outlet of the cooling tower. The first circulation pipeline exchanges heat with the steam pipeline through the heat exchanger, and the first circulation pipeline is connected to the cooling water pump.

5. A sewage sludge treatment method according to claim 3, characterized in that: The steam condensation device includes an evaporator, a compressor, a condenser, an expansion valve, and a second circulation pipeline. The second circulation pipeline sequentially passes through the evaporator, the compressor, the condenser, and the expansion valve. The second circulation pipeline exchanges heat with the steam pipeline through the evaporator.

6. A sewage sludge treatment method according to claim 1 or 2 or 4 or 5, characterized in that: At least two sewage and sludge treatment tanks are provided. The two sewage and sludge treatment tanks are heated by the same first tank heating device, or the two sewage and sludge treatment tanks are respectively heated by the first tank heating device, or one of the sewage and sludge treatment tanks is heated by the first tank heating device, and the other sewage and sludge treatment tank is heated by the second tank heating device.

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