Sludge low-temperature waste heat drying coupling carbonization treatment system

Abstract

The utility model discloses a low-temperature waste heat drying coupling carbonization treatment system for sludge, and relates to the technical field of sludge treatment. The system comprises a low-temperature waste heat drying device, a gas treatment branch and a solid treatment branch, the low-temperature waste heat drying device is used for drying the wet sludge to obtain dried sludge and wet and hot air; the solid treatment branch is used for heating the dried sludge to obtain pyrolysis non-condensable gas and medium-temperature pyrolysis carbon, and carrying out cooling and dust suppression treatment on the medium-temperature pyrolysis carbon to obtain low-temperature pyrolysis carbon; the gas treatment branch is used for carrying out incineration treatment on the pyrolysis non-condensable gas and carrying out purification treatment on waste flue gas generated by incineration treatment; and the hot and humid air is dehumidified and heated through waste heat of incineration treatment, and condensate water and dry air are obtained. By arranging the gas treatment branch and the solid treatment branch, the automation level of sludge treatment can be improved, and meanwhile, the water content of solid products after sludge treatment is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of sludge treatment, in particular to a sludge low-temperature waste heat drying coupled carbonization treatment system. Background Art

[0002] Municipal sludge is an inevitable byproduct of sewage treatment. It has a huge output and a low harmless disposal rate, causing great pollution to the environment. The long-term "heavy water and light mud" has led to serious "backlog" of sludge. Municipal sludge has a high water content, a large volume, contains a variety of heavy metal ions, a high organic content, is easy to decay and stink, and contains bacteria. In recent years, the standards and regulations related to sludge have become increasingly strict. Sludge that has not been stabilized is not allowed to enter the land, and the requirements for heavy metals and persistent organic matter have become more stringent.

[0003] At present, the main methods for sludge disposal include deep dehydration sanitary landfill, composting, incineration, anaerobic digestion, sludge carbonization and other technologies. Sanitary landfill: Due to the potential pollution of leachate to groundwater and the reduction of urban land, the requirements for treatment technology standards are getting higher and higher. Many countries and regions even firmly oppose the construction of new landfills. In recent years, the proportion of sludge landfill disposal has become smaller and smaller. For example, the proportion of sludge landfill in the UK has dropped from 27% in 1980 to 10% in 1995, and continued to drop to 6% in 2005. Aerobic composting: Aerobic fermentation composting requires the addition of sawdust, straw and other materials, and is completed through ventilation and air supply, so it consumes electricity. The fertilizer produced is mainly sent to the forestry department for use, and there is a problem of sales. The main problems of sludge composting process are large land occupation and narrow subsequent outlets for compost products. Sludge incineration: It can achieve full treatment of sludge, and can maximize the harmlessness, reduction and resource utilization of sludge. Its disadvantages are that the investment in treatment facilities is large, the treatment cost is high, and the incineration of organic matter will produce some harmful substances. Therefore, the flue gas treatment requirements are high and there are more treatment facilities. Anaerobic digestion: The operation and management are complex, and the investment and operation costs are very high. It is only suitable for large and medium-sized sewage treatment plants. Biogas power generation is not economical, and the back-end of CNG is relatively complicated. The sludge and liquid biogas produced by anaerobic digestion need to be treated. The resource utilization degree is relatively high, but the reduction is not very reasonable. Sludge carbonization: Sludge carbonization technology is a sludge treatment route proposed to address the problems of incomplete sludge treatment and low resource utilization in existing sludge technologies. It conforms to the treatment principle of "harmless, stabilizing, and resource-based" sludge and has the following characteristics: (1) When the sludge is heated under anaerobic conditions, a large amount of volatiles are precipitated, which can reduce the weight by 75-85% and the volume by 95%, thereby achieving sludge reduction. (2) High-temperature reducing atmosphere operation can effectively kill pathogens in the sludge, and heavy metals are stably transferred through high-temperature complexation, reducing the leaching rate, which conforms to the principle of harmless and stabilizing sludge treatment. (3) The pyrolysis gas is isolated from the heating carrier to ensure the calorific value of the pyrolysis gas. After combustion, it is recycled into the heating system to maximize the thermal utilization rate and reduce the use of auxiliary fuels. The pyrolysis biochar can be further used for soil remediation, building materials preparation, etc., to achieve complete resource utilization of sludge. (4) It is carried out in a sealed, oxygen-free, non-combustion, and high-temperature state to avoid the production of harmful substances such as dioxins and nitrogen oxides. The tail gas can meet the emission standards after simple treatment, which has good environmental benefits. (5) It occupies a small area, requires less investment, and has a fast disposal speed.

[0004] like Figure 1-Figure 3The sludge low-temperature waste heat drying machine uses a low-temperature heat source to heat the air and cool the air at the same time to condense and dehydrate the drying method: the waste heat type low-temperature drying system uses the waste heat that meets the corresponding standards on site to replace the dehumidification heat pump for heating and operation. In order to avoid the interference of waste heat thermal energy fluctuations on the automatic operation of the system, the waste heat is not directly used in the drying box to heat and dry the sludge. According to the size of the waste heat fluctuation on site, water with corresponding heat capacity is used as a medium to store energy and maintain the stability of the system. The drying condensation operation is the same as the dehumidification heat pump drying system.

[0005] Problems with existing sludge carbonization technology: (1) The wet sludge moisture content is relatively high, and the wet sludge moisture content is generally required to be controlled at 75% to 85%. Since the wet sludge produced by sewage treatment plants generally has a moisture content of 90% to 98%, the traditional sludge carbonization technology requires the wet sludge to be first passed through a screw press, a centrifuge or a belt filter press to reduce the moisture content to about 80%, and then undergo subsequent drying and carbonization treatment. Therefore, the investment is large, the equipment occupies a large area, and the raw material applicability is poor. (2) The sludge dehydration effect is poor. At present, the sludge moisture content can only be reduced to 60% to 75% through plate and frame filter presses, high-pressure belt filter presses, etc. If the sludge moisture content is to be reduced to about 30%, additional sludge drying equipment is required. For wet sludge with a moisture content of 90% to 98% produced by sewage treatment plants, two or more dehydration systems are required to dehydrate the sludge to a moisture content of about 30%. Therefore, the investment is large, the dehydration efficiency is low, and the operating cost is high. (3) Low automation level. Traditional plate and frame filter presses, vertical presses, etc. require a large number of workers and cannot fully realize automated operation. The sludge dewatering plant has a strong odor and a poor environment, which is harmful to the human body. It requires additional odor treatment equipment, so the labor cost is high, the investment is high, and the operation and management are difficult. (4) Low energy utilization rate. Generally, after the dried sludge with a moisture content of about 30% is carbonized, the pyrolysis gas generated needs to be incinerated. The high-temperature flue gas generated is difficult to effectively utilize its heat, resulting in low system thermal utilization rate and poor project returns. (5) Poor intensive level. Traditional sludge carbonization technology adopts a combined process of "dehydration + drying + carbonization". Two sets of dehydration systems are required alone. Therefore, the system is complex and the intensive level is poor, which is not conducive to operation and management. At the same time, the equipment investment is high, the floor space is large, and the operation cost is high. Utility Model Content

[0006] The utility model aims to provide a sludge low-temperature waste heat drying coupled carbonization treatment system, which can improve the automation level of sludge treatment and reduce the water content of solid products after sludge treatment.

[0007] To achieve the above purpose, the utility model provides the following solutions:

[0008] A sludge low-temperature waste heat drying coupled carbonization treatment system, comprising:

[0009] Low temperature waste heat drying device, gas processing branch and solid processing branch;

[0010] The gas processing branch and the solid processing branch are both connected to the low-temperature waste heat drying device; the gas processing branch is also connected to the solid processing branch;

[0011] The wet sludge inlet of the low-temperature waste heat drying device is used to input wet sludge;

[0012] The low-temperature waste heat drying device is used to dry the wet sludge to obtain dried sludge and moist hot air;

[0013] The solid treatment branch is used to heat the dried sludge to obtain pyrolytic non-condensable gas and medium-temperature pyrolytic carbon, and to cool and suppress the medium-temperature pyrolytic carbon to obtain low-temperature pyrolytic carbon;

[0014] The gas treatment branch is used to incinerate the pyrolysis non-condensable gas and purify the waste flue gas generated by the incineration to obtain qualified flue gas; the waste heat from the incineration is used to dehumidify and heat the hot and humid air to obtain condensed water and dry air, and the dry air is input into the low-temperature waste heat drying device.

[0015] Optionally, the solid processing branch includes: a carbonization device and a discharging device;

[0016] The dried sludge inlet of the carbonization device is connected to the dried sludge outlet of the low-temperature waste heat drying device; the medium-temperature pyrolytic carbon outlet of the carbonization device is connected to the medium-temperature pyrolytic carbon inlet of the discharging device; the pyrolytic non-condensable gas outlet of the carbonization device is connected to the gas processing branch; the natural gas inlet of the carbonization device is used to input natural gas; the carbonization device burns natural gas to heat the dried sludge to obtain pyrolytic non-condensable gas and medium-temperature pyrolytic carbon;

[0017] The condensate inlet of the discharging device is connected to the gas treatment branch; the discharging device is used to use the condensate output by the gas treatment branch to cool the medium-temperature pyrolytic carbon and suppress dust to obtain low-temperature pyrolytic carbon; the sewage outlet of the discharging device is used to discharge the sewage generated during the cooling and dust suppression process.

[0018] Optionally, the discharging device is a water-cooled jacketed spiral device;

[0019] The inner wall of the water-cooling jacket spiral device is provided with a plurality of through holes;

[0020] The condensed water flows in the jacket of the water-cooled jacket spiral device to cool the medium-temperature pyrolytic carbon; the condensed water sprays the medium-temperature pyrolytic carbon through the plurality of through holes to cool it and suppress dust.

[0021] Optionally, the gas processing branch includes: a gas boiler, a dehumidification heat pump system and a flue gas purification device;

[0022] The pyrolysis non-condensable gas inlet of the gas boiler is connected to the pyrolysis non-condensable gas outlet of the carbonization device; the waste flue gas outlet of the gas boiler is connected to the waste flue gas inlet of the flue gas purification device; the hot water outlet of the gas boiler is connected to the hot water inlet of the dehumidification heat pump system; the circulating water inlet of the gas boiler is connected to the circulating water outlet of the dehumidification heat pump system; the gas boiler is used to incinerate the pyrolysis non-condensable gas, input the waste flue gas to the flue gas purification device, and use the waste heat of the incineration process to heat the circulating water output by the dehumidification heat pump system into hot water, and input the hot water into the dehumidification heat pump system;

[0023] The hot and humid air inlet of the dehumidification heat pump system is connected to the hot and humid air outlet of the low-temperature waste heat drying device; the dry air outlet of the dehumidification heat pump system is connected to the dry air inlet of the low-temperature waste heat drying device; the condensed water outlet of the dehumidification heat pump system is connected to the condensed water inlet of the discharge device; the dehumidification heat pump system is used to utilize the heat of the hot water input by the gas boiler in the inner tube to perform dehumidification and heating treatment on the hot and humid air to obtain condensed water and dry air, and the heat of the hot water is absorbed to form circulating water which is input into the gas boiler;

[0024] The flue gas purification device is used to purify the waste flue gas generated by incineration to obtain flue gas that meets the standards; the flue gas that meets the standards is output through the flue gas outlet of the flue gas purification device.

[0025] Optionally, the flue gas purification device is any one of a cyclone separator, a bag filter, an alkali washing tower or an activated carbon adsorption tower.

[0026] Optionally, the flue gas purification device is any of a cyclone separator, a bag dust collector, an alkali washing tower or an activated carbon adsorption tower, and any of the cyclone separator, bag dust collector, alkali washing tower or activated carbon adsorption tower are selected and connected in sequence.

[0027] According to the specific embodiments provided by the utility model, the utility model discloses the following technical effects:

[0028] A sludge low-temperature waste heat drying coupled carbonization treatment system has simple process, low equipment investment, high energy utilization rate, low operating cost, high level of harmlessness, reduction and resource utilization, and is easy to promote and apply in industry. (1) Wide adaptability of raw materials. Since the low-temperature waste heat drying device is used to dry the wet sludge with dry air, it is applicable to wet sludge with a moisture content of 60% to 98%, and has a wide adaptability of raw materials. (2) Good sludge dehydration effect. Since the dry air is used for circulating condensation, dehumidification and drying, the dry air temperature reaches 60% to 85°C, so the dehydration effect is good. (3) High level of automation. Since the low-temperature waste heat drying device does not require manual shoveling like a plate and frame filter press, nor does it require manual adjustment of the filter cloth like a vertical press, it can achieve fully automatic operation, so it has a high level of automation, low labor cost, and convenient operation and management. (4) High energy utilization rate. Since the dried sludge obtained after low-temperature waste heat drying treatment is carbonized, the pyrolysis gas produced by carbonization is directly sent to the gas boiler for incineration treatment. The high-temperature flue gas produced is heat recovered in the gas boiler and hot water is produced. The hot water then condenses the moisture in the humid hot air through the dehumidification heat pump system. Therefore, the whole system has high thermal utilization rate, low operating cost and good project benefits. (5) The system is simple and highly intensive. Since only one set of sludge low-temperature waste heat drying device is needed to dry wet sludge with a moisture content of 60% to 98% to a moisture content of 15% to 35%, the system is simple and highly intensive, which is conducive to operation and management. At the same time, the equipment investment is low, the footprint is small, and the operating cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is the first schematic diagram of the principle of the low-temperature waste heat sludge drying machine in the prior art;

[0031] Figure 2 It is the second schematic diagram of the principle of the low-temperature waste heat sludge drying machine in the prior art;

[0032] Figure 3 The third schematic diagram of the principle of the low-temperature waste heat sludge drying machine in the prior art;

[0033] Figure 4 A schematic diagram of the structure of a sludge low-temperature waste heat drying coupled carbonization treatment system provided in Example 1 of the utility model;

[0034] Figure 5A diagram showing a first implementation of a dehumidification heat pump system provided in Example 1 of the utility model;

[0035] Figure 6 A second implementation diagram of the dehumidification heat pump system provided in Example 1 of the utility model;

[0036] Figure 7 This is a diagram of the third implementation method of the dehumidification heat pump system provided in Example 1 of the utility model.

[0037] Explanation of symbols: low-temperature waste heat drying device-1; carbonization device-2; gas boiler-3; dehumidification heat pump system-4; flue gas purification device-5; discharge device-6. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] The utility model aims to provide a sludge low-temperature waste heat drying coupled carbonization treatment system, which can improve the automation level of sludge treatment and reduce the water content of solid products after sludge treatment.

[0040] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0041] Example 1

[0042] like Figure 4 As shown, a sludge low-temperature waste heat drying coupled carbonization treatment system in this embodiment includes: a low-temperature waste heat drying device, a gas treatment branch and a solid treatment branch; the gas treatment branch and the solid treatment branch are both connected to the low-temperature waste heat drying device; the gas treatment branch is also connected to the solid treatment branch; the wet sludge inlet of the low-temperature waste heat drying device is used to input wet sludge; the low-temperature waste heat drying device is used to dry the wet sludge to obtain dried sludge and moist hot air; the solid treatment branch is used to heat the dried sludge to obtain pyrolysis non-condensable gas and medium-temperature pyrolysis charcoal, and to cool and suppress the medium-temperature pyrolysis charcoal to obtain low-temperature pyrolysis charcoal; the gas treatment branch is used to incinerate the pyrolysis non-condensable gas, and to purify the waste flue gas generated by the incineration treatment to obtain qualified flue gas; the waste heat from the incineration treatment is used to dehumidify and heat the moist hot air to obtain condensed water and dry air, and the dry air is input into the low-temperature waste heat drying device.

[0043] The solid processing branch includes: a carbonization device and a discharging device.

[0044] The dried sludge inlet of the carbonization device is connected to the dried sludge outlet of the low-temperature waste heat drying device; the medium-temperature pyrolytic carbon outlet of the carbonization device is connected to the medium-temperature pyrolytic carbon inlet of the discharging device; the pyrolytic non-condensable gas outlet of the carbonization device is connected to the gas treatment branch; the natural gas inlet of the carbonization device is used to input natural gas; the carbonization device burns natural gas to heat the dried sludge to obtain pyrolytic non-condensable gas and medium-temperature pyrolytic carbon.

[0045] The condensate inlet of the discharging device is connected to the gas treatment branch; the discharging device is used to use the condensate output from the gas treatment branch to cool the medium-temperature pyrolytic carbon and suppress dust to obtain low-temperature pyrolytic carbon; the sewage outlet of the discharging device is used to discharge the sewage generated during the cooling and dust suppression process.

[0046] Among them, the discharging device is a water-cooled jacket spiral device; the inner wall of the water-cooled jacket spiral device is provided with multiple through holes; condensed water flows in the jacket of the water-cooled jacket spiral device to cool the medium-temperature pyrolytic carbon; the condensed water sprays the medium-temperature pyrolytic carbon through the multiple through holes to cool it down and suppress dust.

[0047] The gas processing branch includes: gas boiler, dehumidification heat pump system and flue gas purification device.

[0048] The pyrolysis non-condensable gas inlet of the gas boiler is connected to the pyrolysis non-condensable gas outlet of the carbonization device; the waste flue gas outlet of the gas boiler is connected to the waste flue gas inlet of the flue gas purification device; the hot water outlet of the gas boiler is connected to the hot water inlet of the dehumidification heat pump system; the circulating water inlet of the gas boiler is connected to the circulating water outlet of the dehumidification heat pump system; the gas boiler is used to incinerate the pyrolysis non-condensable gas, input the waste flue gas into the flue gas purification device, and use the waste heat from the incineration to heat the circulating water output by the dehumidification heat pump system into hot water, and input the hot water into the dehumidification heat pump system.

[0049] The hot and humid air inlet of the dehumidification heat pump system is connected to the hot and humid air outlet of the low-temperature waste heat drying device; the dry air outlet of the dehumidification heat pump system is connected to the dry air inlet of the low-temperature waste heat drying device; the condensed water outlet of the dehumidification heat pump system is connected to the condensed water inlet of the discharge device; the dehumidification heat pump system is used to utilize the heat of the hot water input by the gas boiler in the inner tube to dehumidify and heat the hot and humid air to obtain condensed water and dry air, and the heat of the hot water is absorbed to form circulating water and input into the gas boiler.

[0050] The flue gas purification device is used to purify the waste flue gas generated by incineration to obtain flue gas that meets the standards; the flue gas that meets the standards is output through the flue gas outlet of the flue gas purification device.

[0051] The flue gas purification device is any one of a cyclone separator, a bag dust collector, an alkali washing tower or an activated carbon adsorption tower. Or the flue gas purification device is any of a cyclone separator, a bag dust collector, an alkali washing tower or an activated carbon adsorption tower, and any selected ones of the cyclone separator, the bag dust collector, the alkali washing tower or the activated carbon adsorption tower are connected in sequence.

[0052] Specifically, the system includes a low-temperature waste heat drying device 1, a carbonization device 2, a gas boiler 3, a dehumidification heat pump system 4, a flue gas purification device 5 and a discharge device 6.

[0053] The low temperature waste heat drying device 1 has a wet sludge inlet, a dry air inlet, a dried sludge outlet and a wet hot air outlet. The low temperature waste heat drying device 1 is used to dry the wet sludge to obtain dried sludge.

[0054] The carbonization device 2 has a dried sludge inlet, a natural gas inlet, a pyrolysis non-condensable gas outlet, and a medium-temperature pyrolysis char outlet. The dried sludge inlet of the carbonization device 2 is connected to the dried sludge outlet of the low-temperature waste heat drying device 1. The carbonization device 2 is used to carbonize the dried sludge to obtain pyrolysis non-condensable gas and medium-temperature pyrolysis char.

[0055] Furthermore, the carbonization device 2 adopts the internal heat carbonization principle, using the high-temperature flue gas obtained by burning natural gas to directly contact and heat the dried sludge, thereby completing the carbonization reaction.

[0056] The gas boiler 3 has a pyrolysis non-condensable gas inlet, a circulating water inlet, a waste flue gas outlet and a hot water outlet. The pyrolysis non-condensable gas inlet of the gas boiler 3 is connected to the pyrolysis non-condensable gas outlet of the carbonization device 2. The gas boiler 3 is used to incinerate the pyrolysis non-condensable gas and utilize the waste heat to obtain waste flue gas and hot water.

[0057] The dehumidification heat pump system 4 has a hot and humid air inlet, a hot water inlet, a condensed water outlet, a dry air outlet and a circulating water outlet. The hot and humid air inlet of the dehumidification heat pump system 4 is connected to the hot and humid air outlet of the low-temperature waste heat drying device 1, the hot water inlet of the dehumidification heat pump system 4 is connected to the hot water outlet of the gas boiler 3, the dry air outlet of the dehumidification heat pump system 4 is connected to the dry air inlet of the low-temperature waste heat drying device 1, and the circulating water outlet of the dehumidification heat pump system 4 is connected to the circulating water inlet of the gas boiler 3. The dehumidification heat pump system 4 is used to dehumidify and heat the hot and humid air to obtain condensed water, dry air and circulating water.

[0058] Furthermore, the dehumidification heat pump system 4 includes a compressor, an expansion valve, an evaporator and a condenser. The dehumidification heat pump system adopts the reverse Carnot cycle principle and uses electric energy to drive the compressor to work, so that the water vapor in the hot and humid air is cooled through the evaporator to condense water and discharged. After passing through the condenser to increase the temperature, the heated dry air can continue to absorb the moisture in the wet sludge due to unsaturation, thereby playing a drying role. Condenser (heating process): converts the high-temperature and high-pressure refrigerant gas into liquid, and transfers the heat in the pipe to the nearby air. The working process of the condenser is an exothermic process. Evaporator (refrigeration process): the low-temperature and low-pressure refrigerant liquid is heat exchanged with the outside air through the evaporator, and gasification absorbs heat. The working process of the evaporator is an endothermic process. The function of the compressor is to compress the low-temperature and low-pressure gas into a high-temperature and high-pressure gas and send it to the condenser. Expansion valve: plays a throttling role in the system; the high-temperature and high-pressure refrigerant liquid becomes a low-temperature and low-pressure gas after throttling through the expansion valve. Dehumidification heat pump system implementation method Figures 5 to 7 .

[0059] The flue gas purification device 5 has a waste flue gas inlet and a standard flue gas outlet. The waste flue gas inlet of the flue gas purification device 5 is connected to the waste flue gas outlet of the gas boiler 3. The flue gas purification device 5 is used to purify the waste flue gas to obtain standard flue gas.

[0060] Furthermore, the flue gas purification device 5 includes one or a combination of a cyclone separator, a bag filter, an alkali washing tower, and an activated carbon adsorption tower.

[0061] The discharge device 6 has a medium-temperature pyrolytic carbon inlet, a condensed water inlet, a low-temperature pyrolytic carbon outlet and a sewage outlet. The medium-temperature pyrolytic carbon inlet of the discharge device 6 is connected to the medium-temperature pyrolytic carbon outlet of the carbonization device 2, and the condensed water inlet of the discharge device 6 is connected to the condensed water outlet of the dehumidification heat pump 4 system. The discharge device 6 is used to cool the medium-temperature pyrolytic carbon and suppress dust at the same time, so as to obtain low-temperature pyrolytic carbon and sewage.

[0062] Furthermore, the discharging device 6 adopts a water-cooled jacket spiral device, and condensed water is passed into the jacket of the water-cooled jacket spiral device to cool the medium-temperature pyrolytic carbon.

[0063] Furthermore, the inner wall of the water-cooled jacket spiral device is provided with a plurality of small holes so as to spray and cool the medium-temperature pyrolytic carbon to play a role in dust suppression.

[0064] (1) Wet sludge with a moisture content of 70% to 98% is sent to a low-temperature waste heat drying device for drying to obtain dried sludge with a moisture content of 15% to 35%.

[0065] (2) The dried sludge is sent to a carbonization device for carbonization treatment to obtain 500°C to 700°C pyrolysis non-condensable gas and 400°C to 500°C medium-temperature pyrolysis carbon.

[0066] (3) The pyrolysis non-condensable gas is sent to a gas boiler for incineration and waste heat utilization to obtain waste flue gas at 200°C to 250°C and hot water at 70°C to 95°C.

[0067] (4) The hot water is sent to the dehumidification heat pump system for heat exchange treatment to obtain dry air at 60°C to 85°C and circulating water at 50°C to 75°C.

[0068] (5) The hot dry air is sent to the low-temperature waste heat drying device as a heat source for sludge drying, so as to improve the thermal utilization rate of the system and reduce the operating cost, and obtain 45°C to 70°C moist hot air and 15% to 35% moisture content dried sludge.

[0069] (6) The hot and humid air is sent to the dehumidification heat pump system for heat exchange treatment to obtain condensed water and dry air at 60℃~85℃.

[0070] (7) The waste flue gas is sent to a flue gas purification device for purification so as to obtain flue gas that meets the standards.

[0071] (8) The medium-temperature pyrolytic carbon is discharged through a discharging device to obtain low-temperature pyrolytic carbon at 50° C. to 80° C.

[0072] Example 2

[0073] The wet sludge with a moisture content of 70% is sent to the low-temperature waste heat drying device 1 for drying treatment to obtain dried sludge with a moisture content of 15%. The dried sludge is sent to the carbonization device 2 for carbonization treatment to obtain 700°C pyrolysis non-condensable gas and 500°C medium-temperature pyrolysis carbon. The pyrolysis non-condensable gas is sent to the gas boiler 3 for incineration treatment and waste heat utilization to obtain 250°C waste flue gas and 95°C hot water. The hot water is sent to the dehumidification heat pump system 4 for heat exchange treatment to obtain 85°C dry air and 75°C circulating water. The hot dry air is sent to the low-temperature waste heat drying device 1 as a heat source for sludge drying, so as to improve the system's thermal utilization rate and reduce operating costs, and obtain 70°C humid hot air and dried sludge with a moisture content of 15%. The humid hot air is sent to the dehumidification heat pump system 4 for heat exchange treatment to obtain condensed water and 85°C dry air. The waste flue gas is sent to the flue gas purification device for purification treatment to obtain qualified flue gas. The flue gas purification device 5 includes a cyclone separator, a bag filter, an alkali washing tower, and an activated carbon adsorption tower. The medium-temperature pyrolytic carbon is discharged through the discharging device to obtain 80°C low-temperature pyrolytic carbon. The discharging device 6 adopts a water-cooled jacket spiral device to directly and indirectly cool the medium-temperature pyrolytic carbon. The system has simple process, low equipment investment, high energy utilization, low operating cost, high level of harmlessness, reduction and resource utilization, and is easy to promote and apply industrially.

[0074] Example 3

[0075] The wet sludge with a moisture content of 98% is sent to the low-temperature waste heat drying device 1 for drying treatment to obtain dried sludge with a moisture content of 35%. The dried sludge is sent to the carbonization device 2 for carbonization treatment to obtain 500°C pyrolysis non-condensable gas and 400°C medium-temperature pyrolysis carbon. The pyrolysis non-condensable gas is sent to the gas boiler 3 for incineration treatment and waste heat utilization to obtain 200°C waste flue gas and 70°C hot water. The hot water is sent to the dehumidification heat pump system 4 for heat exchange treatment to obtain 60°C dry air and 50°C circulating water. The hot dry air is sent to the low-temperature waste heat drying device 1 as a heat source for sludge drying to improve the thermal utilization rate of the system and reduce the operating cost, and obtain 60°C humid hot air and dried sludge with a moisture content of 35%. The humid hot air is sent to the dehumidification heat pump system 4 for heat exchange treatment to obtain condensed water and 60°C dry air. The waste flue gas is sent to the flue gas purification device for purification treatment to obtain qualified flue gas. The flue gas purification device 5 includes a bag filter, an alkali washing tower, and an activated carbon adsorption tower. The medium-temperature pyrolytic carbon is discharged through the discharging device to obtain 50°C low-temperature pyrolytic carbon. The discharging device 6 adopts a water-cooled jacket spiral device to directly and indirectly cool the medium-temperature pyrolytic carbon. The system has simple process, low equipment investment, high energy utilization, low operating cost, high level of harmlessness, reduction and resource utilization, and is easy to promote and apply industrialization.

[0076] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] This article uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the system and core ideas of the utility model. At the same time, for those skilled in the art, according to the ideas of the utility model, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the utility model.

Claims

1. A sludge low-temperature waste heat drying coupled carbonization treatment system, characterized in that: include: Low temperature waste heat drying device, gas processing branch and solid processing branch; The gas processing branch and the solid processing branch are both connected to the low-temperature waste heat drying device; the gas processing branch is also connected to the solid processing branch; The wet sludge inlet of the low-temperature waste heat drying device is used to input wet sludge; The low-temperature waste heat drying device is used to dry the wet sludge to obtain dried sludge and moist hot air; The solid treatment branch is used to heat the dried sludge to obtain pyrolytic non-condensable gas and medium-temperature pyrolytic carbon, and to cool and suppress the medium-temperature pyrolytic carbon to obtain low-temperature pyrolytic carbon; The gas treatment branch is used to incinerate the pyrolysis non-condensable gas and purify the waste flue gas generated by the incineration to obtain qualified flue gas; the waste heat from the incineration is used to dehumidify and heat the hot and humid air to obtain condensed water and dry air, and the dry air is input into the low-temperature waste heat drying device.

2. A sludge low-temperature waste heat drying coupled carbonization treatment system according to claim 1, characterized in that: The solid processing branch includes: a carbonization device and a discharging device; The dried sludge inlet of the carbonization device is connected to the dried sludge outlet of the low-temperature waste heat drying device; the medium-temperature pyrolytic carbon outlet of the carbonization device is connected to the medium-temperature pyrolytic carbon inlet of the discharging device; the pyrolytic non-condensable gas outlet of the carbonization device is connected to the gas processing branch; the natural gas inlet of the carbonization device is used to input natural gas; the carbonization device burns natural gas to heat the dried sludge to obtain pyrolytic non-condensable gas and medium-temperature pyrolytic carbon; The condensate inlet of the discharging device is connected to the gas treatment branch; the discharging device is used to use the condensate output by the gas treatment branch to cool the medium-temperature pyrolytic carbon and suppress dust to obtain low-temperature pyrolytic carbon; the sewage outlet of the discharging device is used to discharge the sewage generated during the cooling and dust suppression process.

3. The sludge low-temperature waste heat drying coupled carbonization treatment system according to claim 2 is characterized in that: The discharging device is a water-cooled jacketed spiral device; The inner wall of the water-cooling jacket spiral device is provided with a plurality of through holes; The condensed water flows in the jacket of the water-cooled jacket spiral device to cool the medium-temperature pyrolytic carbon; the condensed water sprays the medium-temperature pyrolytic carbon through the plurality of through holes to cool it and suppress dust.

4. The sludge low-temperature waste heat drying coupled carbonization treatment system according to claim 2 is characterized in that: The gas processing branch includes: a gas boiler, a dehumidification heat pump system and a flue gas purification device; The pyrolysis non-condensable gas inlet of the gas boiler is connected to the pyrolysis non-condensable gas outlet of the carbonization device; the waste flue gas outlet of the gas boiler is connected to the waste flue gas inlet of the flue gas purification device; the hot water outlet of the gas boiler is connected to the hot water inlet of the dehumidification heat pump system; the circulating water inlet of the gas boiler is connected to the circulating water outlet of the dehumidification heat pump system; the gas boiler is used to incinerate the pyrolysis non-condensable gas, input the waste flue gas to the flue gas purification device, and use the waste heat of the incineration process to heat the circulating water output by the dehumidification heat pump system into hot water, and input the hot water into the dehumidification heat pump system; The hot and humid air inlet of the dehumidification heat pump system is connected to the hot and humid air outlet of the low-temperature waste heat drying device; the dry air outlet of the dehumidification heat pump system is connected to the dry air inlet of the low-temperature waste heat drying device; the condensed water outlet of the dehumidification heat pump system is connected to the condensed water inlet of the discharge device; the dehumidification heat pump system is used to utilize the heat of the hot water input by the gas boiler in the inner tube to perform dehumidification and heating treatment on the hot and humid air to obtain condensed water and dry air, and the heat of the hot water is absorbed to form circulating water which is input into the gas boiler; The flue gas purification device is used to purify the waste flue gas generated by incineration to obtain flue gas that meets the standards; the flue gas that meets the standards is output through the flue gas outlet of the flue gas purification device.

5. A sludge low-temperature waste heat drying coupled carbonization treatment system according to claim 4, characterized in that: The flue gas purification device is any one of a cyclone separator, a bag filter, an alkali washing tower or an activated carbon adsorption tower.

6. The sludge low-temperature waste heat drying coupled carbonization treatment system according to claim 4 is characterized in that: The flue gas purification device is any of a cyclone separator, a bag dust collector, an alkali washing tower or an activated carbon adsorption tower, and any of the cyclone separator, bag dust collector, alkali washing tower or activated carbon adsorption tower is selected and connected in sequence.

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