Sludge pyrolysis assembly and sludge pyrolysis system

Abstract

The present invention discloses a sludge pyrolysis assembly and a sludge pyrolysis system. The sludge pyrolysis assembly includes a sludge dryer, a sludge carbonization furnace, a pyrolysis gas combustion furnace, a first heat exchanger, a second heat exchanger, and a condenser. Among them, the sludge is dried by the sludge dryer and then pyrolyzed by the sludge carbonization furnace to decompose the organic components in the sludge. The pyrolysis gas generated by pyrolysis is then burned by the pyrolysis gas combustion furnace. The flue gas generated by the pyrolysis gas combustion furnace is introduced into the sludge carbonization furnace to heat the sludge. The sludge dryer, the first heat exchanger, the condenser, and the second heat exchanger form a closed loop for circulating the drying carrier gas. The drying carrier gas needs to be condensed by the condenser during the circulation process to dehumidify, and the first heat exchanger realizes the heat energy recovery of the drying carrier gas. The second heat exchanger uses the flue gas discharged from the sludge carbonization furnace to heat and raise the temperature of the drying carrier gas. Its structure is simple and the energy consumption is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of sludge treatment, and particularly relates to a sludge pyrolysis assembly and a sludge pyrolysis system. Background Art

[0002] The treatment and utilization of municipal sludge have indeed become an urgent problem to be solved. Traditional sludge treatment methods, such as landfilling, composting, and incineration, often have problems such as high energy consumption and heavy pollution. They not only have low treatment efficiency but also may cause secondary pollution to the environment. As a new sludge treatment method, sludge pyrolysis technology converts the organic matter in sludge into gas, liquid, and solid products through high-temperature pyrolysis, thereby achieving sludge reduction and resource utilization. Compared with traditional methods, sludge pyrolysis technology has significant advantages, such as large processing capacity, high energy utilization efficiency, and reduced pollution.

[0003] However, there are indeed some problems in the practical application of existing sludge pyrolysis technologies, such as low efficiency and low heat energy recovery utilization rate. These problems not only affect the overall efficiency of sludge pyrolysis technology but also may increase the treatment cost and energy consumption. Summary of the Invention

[0004] In order to solve the above technical problems, one of the purposes of the present invention is to provide a sludge pyrolysis assembly, which performs multi-stage dehydration on semi-dry sludge to finally obtain dry sludge. In addition, during the drying process, it can burn the pyrolysis gas generated by drying and use the heat energy generated by combustion to dry the sludge. It has high heat energy utilization efficiency, good drying effect, and does not produce dioxins during drying.

[0005] To achieve the above object, the technical solution of the present invention is as follows: A sludge pyrolysis assembly includes a sludge dryer, a sludge carbonization furnace, a pyrolysis gas combustion furnace, a first heat exchanger, a second heat exchanger, and a condenser. The sludge dryer and the sludge carbonization furnace both have a solid material inlet and a solid material outlet. The sludge dryer also has a carrier gas inlet and a carrier gas outlet. The sludge carbonization furnace has a pyrolysis gas outlet and a heating jacket, and the heating jacket has a flue gas inlet and a flue gas outlet. The pyrolysis gas combustion furnace has a pyrolysis gas inlet and a flue gas outlet. The solid material outlet of the sludge dryer is communicated with the solid material inlet of the sludge carbonization furnace. The pyrolysis gas outlet of the sludge carbonization furnace is communicated with the pyrolysis gas inlet of the pyrolysis gas combustion furnace. The flue gas outlet of the pyrolysis gas combustion furnace is communicated with the flue gas inlet of the heating jacket. The carrier gas outlet of the sludge dryer is communicated with the heat medium inlet of the first heat exchanger. The heat medium outlet of the first heat exchanger is communicated with the refrigerant inlet of the first heat exchanger through the condenser. The refrigerant outlet of the first heat exchanger is communicated with the refrigerant inlet of the second heat exchanger. The refrigerant outlet of the second heat exchanger is communicated with the carrier gas inlet of the sludge dryer. The flue gas outlet of the heating jacket is communicated with the heat medium inlet of the second heat exchanger. The condenser is used to cool and dehumidify the drying carrier gas passing through it.

[0006] The beneficial effects of the above technical solution are as follows: In this way, the pyrolysis gas combustion furnace can be used to burn and generate high-temperature flue gas, and the high-temperature flue gas is supplied to the heating jacket to heat the sludge carbonization furnace to pyrolyze the organic components in the sludge to generate pyrolysis gas, and the pyrolysis gas is then introduced into the pyrolysis gas combustion furnace for combustion to generate heat. The flue gas discharged from the heating jacket can also be used to heat the drying carrier gas of the sludge dryer. Among them, the sludge dryer, the first heat exchanger, the condenser, and the other heat exchanger form a circulating gas path for the drying carrier gas. Among them, the drying carrier gas discharged from the sludge dryer carries a lot of moisture. In order to realize the circulation of the drying carrier gas, it is necessary to dehumidify the drying carrier gas. The first heat exchanger first cools and then heats the drying carrier gas. Its cooling is to cool the drying carrier gas entering the condenser, and its heating is to heat the drying carrier gas dehumidified by the condenser. Moreover, the heating and cooling of the drying carrier gas realize the exchange of heat energy. It can effectively utilize heat energy and dehumidify the drying carrier gas before it enters the sludge dryer. The second heat exchanger uses the flue gas discharged from the heating jacket to heat the drying carrier gas before it enters the sludge dryer, so as to further improve the drying effect of the sludge. The sludge dried by the sludge dryer is sent to the sludge carbonization furnace for pyrolysis treatment.

[0007] The above technical solution further includes a dust collector, and the dust collector is arranged at the connection between the carrier gas outlet of the sludge dryer and the heat medium inlet of the first heat exchanger.

[0008] The beneficial effects of the above technical solution are as follows: In this way, the dust collector can be used to remove dust from the circulating drying carrier gas.

[0009] The above technical solution further includes a circulation fan, which is arranged at the connection between the condenser and the refrigerant inlet of the first heat exchanger, and is used to pump the carrier gas dehumidified by the condenser into the refrigerant channel of the first heat exchanger.

[0010] The beneficial effects of the above technical solution are as follows: In this way, the circulation fan can provide power for the circulation of the drying carrier gas.

[0011] The above technical solution further includes a high-temperature fan, the air inlet of which is communicated with the flue gas outlet of the heating jacket, and the air outlet of which is communicated with the carrier gas inlet of the sludge dryer.

[0012] The beneficial effects of the above technical solution are as follows: In this way, the high-temperature fan can send part of the flue gas discharged from the heating jacket into the sludge dryer to supplement the drying carrier gas.

[0013] The above technical solution further includes a tail gas treatment station, the heat medium outlet of the second heat exchanger is communicated with the tail gas inlet of the tail gas treatment station, and the heat medium outlet of the first heat exchanger is communicated with the tail gas inlet of the tail gas treatment station or with the pyrolysis gas inlet of the pyrolysis gas combustion furnace.

[0014] The beneficial effects of the above technical solution are as follows: The flue gas passage and the drying carrier gas passage are also both communicated with the tail gas treatment station, so that the tail gas discharged from the entire sludge pyrolysis assembly can be harmlessly treated before being discharged, which is environmentally friendly.

[0015] The above technical solution further includes a sludge carbon bin, and the solid material outlet of the sludge carbonization furnace is communicated with the sludge carbon bin through a screw feeder.

[0016] The beneficial effects of the above technical solution are as follows: In this way, the sludge treated by the sludge carbonization furnace is sent into the sludge carbon bin through the bolt feeder for collection and finally transported away by a sludge transfer vehicle.

[0017] The above technical solution further includes a urea storage tank for supplying urea solution to the pyrolysis gas combustion furnace.

[0018] The beneficial effects of the above technical solution are as follows: In this way, the urea storage tank can spray urea into the pyrolysis gas combustion furnace to reduce the content of nitrogen oxides in the flue gas.

[0019] The second object of the present invention is to provide a sludge pyrolysis system with a simple structure and capable of drying the transported sludge.

[0020] To achieve the above object, the technical solution of the present invention is as follows: A sludge pyrolysis system includes a first scraper conveyor, a sludge pretreatment station, and the sludge pyrolysis assembly as described above. There are two sludge pretreatment stations. The sludge outlets of the two sludge pretreatment stations are both connected to the solid material inlet of the sludge dryer through the first scraper conveyor. The two sludge pretreatment stations are respectively a first sludge pretreatment station and a second sludge pretreatment station. The first sludge pretreatment station is used to perform pre-dehydration treatment on the incoming wet sludge, and the second sludge pretreatment station is used to perform crushing treatment on the incoming semi-dry sludge.

[0021] The beneficial effect of the above technical solution is that: in this way, it is possible to select whether to be processed by the first sludge pretreatment station or the second sludge pretreatment station according to the moisture content of the transported sludge. Sludge with a high moisture content is processed by the first sludge pretreatment station, and sludge with a low moisture content is processed by the second sludge pretreatment station.

[0022] In the above technical solution, the first sludge pretreatment station includes a wet sludge bin, a sludge pump, a sludge metering bin, a modification mixer, a high-pressure belt deep dewatering machine, a lime storage tank, and an iron salt storage tank. The wet sludge bin, the sludge pump, the sludge metering bin, the modification mixer, and the high-pressure belt deep dewatering machine are connected in sequence. Both the lime storage tank and the iron salt storage tank are connected to the modification mixer. The sludge outlet of the high-pressure belt deep dewatering machine is connected to the feed inlet of the first scraper conveyor.

[0023] The beneficial effect of the above technical solution is that: Wet sludge with a moisture content of 80 - 83% is transported to the wet sludge bin by a sludge transfer vehicle for transfer storage, and the sludge is lifted to the sludge metering bin by a sludge pump; the sludge in the sludge metering bin is sent to the modification mixer to be mixed and modified with lime and iron salt (using chemical methods and electrochemistry methods to condition and modify the sludge) to improve the sludge dewatering performance; the modified sludge is evenly distributed on the filter belt of the high-pressure belt deep dewatering machine for continuous pressure filtration to produce a sludge cake with a moisture content of about 60%. Such sludge meets the processing requirements of the sludge pyrolysis assembly.

[0024] In the above technical solution, the second sludge pretreatment station includes a cake bin, a second scraper conveyor, and a sludge crusher that are connected in sequence. The sludge outlet of the sludge crusher is connected to the feed inlet of the first scraper conveyor.

[0025] The beneficial effect of the above technical solution is that: If the moisture content of the transported sludge is about 60%, it can be directly crushed into particles and processed by the sludge pyrolysis assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of the sludge pyrolysis assembly described in Embodiment 1 of the present invention;

[0027] Figure 2 Schematic diagram of the sludge carbonization furnace in Embodiment 1 of the present invention;

[0028] Figure 3 Schematic diagram of the flow directions of sludge, flue gas, and drying carrier gas of the sludge pyrolysis assembly in Embodiment 1 of the present invention;

[0029] Figure 4 Schematic structural diagram of the sludge pyrolysis system described in Embodiment 2 of the present invention;

[0030] Figure 5 Schematic structural diagram of the first scraper conveyor and two sludge pretreatment stations described in Embodiment 2 of the present invention.

[0031] In the figure: 1 sludge dryer; 2 sludge carbonization furnace; 21 heating jacket; 3 pyrolysis gas combustion furnace; 4 first heat exchanger; 5 second heat exchanger; 6 condenser; 7 tail gas treatment station; 71 spray tower; 72 induced draft fan; 73 discharge stack; 74 alkali liquid storage tank; 8 dust collector; 9 circulation fan; 10 high-temperature fan; 11 sludge carbon bin; 12 screw feeder; 13 tube chain conveyor; 14 urea storage tank; 100 sludge pyrolysis assembly; 200 first scraper conveyor; 300 sludge pretreatment station; 300a first sludge pretreatment station; 300b second sludge pretreatment station; 301 wet sludge bin; 302 sludge pump; 303 sludge metering bin; 304 modification mixer; 305 high-pressure belt deep dewatering machine; 306 lime storage tank; 307 ferric salt storage tank; 308 cake bin; 309 second scraper conveyor; 310 sludge crusher. Detailed implementation manners

[0032] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. In the following paragraphs, the present invention is described more specifically by way of example with reference to the accompanying drawings. The advantages and features of the present invention will be clearer according to the following description and the claims. It should be noted that the accompanying drawings are all in very simplified forms and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0033] Embodiment 1

[0034] As Figure 1 shown, this embodiment provides a sludge pyrolysis assembly, including a sludge dryer 1, a sludge carbonization furnace 2, a pyrolysis gas combustion furnace 3, a first heat exchanger 4, a second heat exchanger 5, a condenser 6, and a tail gas treatment station 7. Both the sludge dryer 1 and the sludge carbonization furnace 2 have a solid material inlet and a solid material outlet. The sludge dryer 1 also has a carrier gas inlet and a carrier gas outlet. The sludge carbonization furnace 2 has a pyrolysis gas outlet and a heating jacket 21 (as Figure 2As shown, the heating jacket 21 has a flue gas inlet and a flue gas outlet, the pyrolysis gas combustion furnace 3 has a pyrolysis gas inlet and a flue gas outlet, the solid material outlet of the sludge dryer 1 is communicated with the solid material inlet of the sludge carbonization furnace 2, the pyrolysis gas outlet of the sludge carbonization furnace 2 is communicated with the pyrolysis gas inlet of the pyrolysis gas combustion furnace 3, and the flue gas outlet of the pyrolysis gas combustion furnace 3 is communicated with the flue gas inlet of the heating jacket 21; the carrier gas outlet of the sludge dryer 1 is communicated with the heat medium inlet of the first heat exchanger 4, the heat medium outlet of the first heat exchanger passes through the condenser 6 and is communicated with the refrigerant inlet of the first heat exchanger 4, the refrigerant outlet of the first heat exchanger 4 is communicated with the refrigerant inlet of the second heat exchanger 5, the refrigerant outlet of the second heat exchanger 5 is communicated with the carrier gas inlet of the sludge dryer 1, the flue gas outlet of the heating jacket 21 is communicated with the heat medium inlet of the second heat exchanger 5, the heat medium outlet of the second heat exchanger 5 is communicated with the tail gas inlet of the tail gas treatment station 7, and the heat medium outlet of the first heat exchanger 4 is communicated with the tail gas inlet of the tail gas treatment station 7 or the pyrolysis gas inlet of the pyrolysis gas combustion furnace 3 [Of course, the connection point of the drying carrier gas channel with the tail gas treatment station or the pyrolysis gas combustion furnace can also be set at the heat medium inlet of the first heat exchanger or the heat medium outlet of the second heat exchanger (as shown in Figure 3 ), and of course, it is not limited to this], and the condenser 6 is used to cool and dehumidify the drying carrier gas passing through it. In this way, high-temperature flue gas generated by the combustion of the pyrolysis gas combustion furnace can be utilized, and the high-temperature flue gas is supplied to the heating jacket to heat the sludge carbonization furnace to pyrolyze the organic components in the sludge to generate pyrolysis gas, and the pyrolysis gas is then introduced into the pyrolysis gas combustion furnace for combustion to generate heat. The flue gas discharged from the heating jacket can also be used to heat the drying carrier gas of the sludge dryer. Among them, the sludge dryer, the first heat exchanger, the condenser, and the second heat exchanger form a circulating gas path for the drying carrier gas. Among them, the drying carrier gas discharged from the sludge dryer carries a lot of moisture. In order to realize the circulation of the drying carrier gas, it is necessary to dehumidify the drying carrier gas. The first heat exchanger first cools and then heats the drying carrier gas. Its cooling is to cool the drying carrier gas entering the condenser, and its heating is to heat the drying carrier gas dehumidified by the condenser. Moreover, the heating and cooling of the drying carrier gas realize the exchange of heat energy, which can effectively utilize heat energy, and dehumidify the drying carrier gas before it enters the sludge dryer. The second heat exchanger uses the flue gas discharged from the heating jacket to heat the drying carrier gas before it enters the sludge dryer, so as to further improve the drying effect of the sludge. The sludge dried by the sludge dryer is sent to the sludge carbonization furnace for pyrolysis treatment, and both the flue gas path and the drying carrier gas path are also communicated with the tail gas treatment station, so that the tail gas discharged from the entire sludge pyrolysis assembly can be harmlessly treated before being discharged, which is friendly to the environment. Figure 3 As shown, and of course, it is not limited to this.

[0035] The above technical solution further includes a dust collector 8, which is arranged at the connection between the carrier gas outlet of the sludge dryer 1 and the heat medium inlet of the first heat exchanger 4, so that the dust collector can dust the circulating drying carrier gas.

[0036] The above technical solution further includes a circulation fan 9, which is arranged at the connection between the condenser 6 and the refrigerant inlet of the first heat exchanger 4, and is used to pump the carrier gas dehumidified by the condenser 6 into the refrigerant channel of the first heat exchanger 4, so that the circulation fan can provide power for the circulation of the drying carrier gas.

[0037] The above technical solution further includes a high-temperature fan 10, the air inlet of which is connected to the flue gas outlet of the heating jacket 21, and the air outlet of which is connected to the carrier gas inlet of the sludge dryer 1, so that the high-temperature fan can send a part of the flue gas discharged from the heating jacket into the sludge dryer to supplement the drying carrier gas.

[0038] In the above technical solution, the tail gas treatment station 7 includes a spray tower 71, a draft fan 72, an exhaust stack 73 and an alkali liquor storage tank 74. The spray tower 71 has a tail gas inlet, a tail gas outlet and an alkali liquor inlet. The heat medium outlet of the second heat exchanger 5 and the heat medium outlet of the first heat exchanger 4 are both connected to the tail gas inlet of the spray tower 71. The tail gas outlet of the spray tower 71 is connected to the exhaust stack 73 through the draft fan 72, and the alkali liquor storage tank 74 is connected to the alkali liquor inlet of the spray tower 71, which performs denitrification and desulfurization treatment on the tail gas. Among them, the tail gas inlet of the spray tower is the tail gas inlet of the tail gas treatment station.

[0039] The above technical solution further includes a sludge carbon bin 11. The solid material outlet of the sludge carbonization furnace 2 is connected to the sludge carbon bin 11 through a screw feeder 12 (preferably, a tube chain conveyor 13 can be additionally arranged between the screw feeder 12 and the sludge carbon bin for transportation). In this way, the sludge treated by the sludge carbonization furnace is sent into the sludge carbon bin through the screw feeder for collection and finally transported away by a sludge transfer vehicle.

[0040] The above technical solution further includes a urea storage tank 14 for supplying urea solution to the pyrolysis gas combustion furnace 3, so that the urea storage tank can spray urea into the pyrolysis gas combustion furnace to reduce the content of nitrogen oxides in the flue gas.

[0041] In this embodiment, both the sludge dryer and the sludge carbonization furnace are of a tunnel structure. Among them, the direction of the sludge in the sludge dryer is in reverse heat exchange drying with the drying carrier gas. Similarly, the direction of the sludge in the sludge carbonization furnace is in reverse heat exchange carbonization with the high-temperature flue gas.

[0042] In this embodiment, there are two gas passages, namely the drying carrier gas circulation passage and the flue gas passage. For the entire drying carrier gas circulation passage, in addition to carrying out moisture in the sludge dryer, it will also carry out some odor components in the sludge, which leads to the accumulation of odor gases in the drying carrier gas. In order to keep the drying carrier gas uniform, it is necessary to have both outflows (discharging part of the drying carrier gas, with the discharge amount being about 10 vol%) and inflows (supplementing part of the fresh drying carrier gas) during the circulation of the drying carrier gas. The part of the drying carrier gas discharged from the drying carrier gas circulation passage is discharged to the tail gas treatment station through the heat medium outlet of the first heat exchanger, while the fresh drying carrier gas supplemented to the drying carrier gas circulation passage is the flue gas supplemented into the sludge dryer by the high-temperature fan through the flue gas outlet of the heating jacket.

[0043] Of course, preferably, the heat medium outlet of the first heat exchanger may not be connected to the tail gas treatment station, but directly connected to the pyrolysis gas inlet of the pyrolysis gas combustion furnace, so that the drying carrier gas discharged from the drying carrier gas circulation passage can be directly sent into the pyrolysis gas combustion furnace for combustion treatment (since the odor gases entrained in the drying carrier gas are more convenient to be treated by combustion, which can reduce the treatment burden of the tail gas treatment station).

[0044] In this embodiment, the sludge fed into the solid material inlet of the sludge desiccant is granular or powdered sludge with a moisture content of about 60%, and the moisture content of the sludge discharged from the solid material outlet of the sludge dryer is about 20%.

[0045] The drying temperature in the sludge dryer is 180 - 300 °C, and the temperature of the sludge in the sludge dryer is heated to 250 - 280 °C (at this temperature, the organic components contained in the sludge are not likely to generate dioxins), and the moisture content of the sludge drops to about 20%.

[0046] The temperature of the flue gas discharged from the pyrolysis gas combustion furnace is 1000 - 1200 °C;

[0047] The temperature of the flue gas discharged from the sludge carbonization furnace is 550 - 600 °C, and the temperature of the sludge in the sludge carbonization furnace is about 650 - 700 °C.

[0048] In this embodiment, the temperature of the drying carrier gas discharged from the sludge dryer is about 180°C (characterized by high dust, high odor, and steam close to saturation), so a dust collector needs to be set up for dust removal and a condenser for dehumidification. After the drying carrier gas passes through the first heat exchanger, the temperature drops from 180°C to 100°C, and then enters the condenser. The condenser cools the drying carrier gas so that the moisture in the drying carrier gas condenses into water droplets and is removed. Through indirect gas-water heat exchange, the temperature is cooled to 40°C by the condenser, and the nearly saturated water vapor turns into condensed water and is removed. Then the circulation fan sends the dehumidified drying carrier gas back into the first heat exchanger for heating up, thereby recovering the heat in the drying carrier gas, and then enters the second heat exchanger to be heated by the flue gas to about 590°C.

[0049] In this embodiment, the fuel of the pyrolysis gas combustion furnace can be mainly biomass or natural gas. In this embodiment, the pyrolysis gas combustion furnace provides heat energy for the entire sludge pyrolysis assembly, and the transfer of its heat energy is conducted with flue gas as the medium. After the flue gas is generated by the pyrolysis gas combustion furnace, it passes through the sludge carbonization furnace and the second heat exchanger in sequence and then is discharged to the tail gas treatment station for treatment. After the flue gas exchanges heat in the second heat exchanger, the temperature drops to about 150°C, and then enters the alkaline spray tower for washing to remove acidic gases and dust in the flue gas, and then is discharged through the induced draft fan into the discharge stack.

[0050] In this embodiment, the sludge carbonization furnace has a sludge channel, and its heating jacket is sleeved outside the sludge channel. The pyrolysis gas outlet of the sludge carbonization furnace is communicated with the sludge channel. Since the pyrolysis gas generated during the pyrolysis of sludge is in the sludge channel, it needs to be transported into the pyrolysis gas combustion furnace through the pyrolysis gas outlet communicated with the sludge channel.

[0051] As Figures 1 - 3 shown, the marks of the solid material inlet, solid material outlet, carrier gas inlet, and carrier gas outlet of the sludge dryer are A, B, C, and D respectively; the marks of the heat medium inlet, heat medium outlet, cold medium inlet, and cold medium outlet of the first heat exchanger are E, F, G, and H respectively; the marks of the heat medium inlet, heat medium outlet, heat medium inlet, and cold medium outlet of the second heat exchanger are I, J, K, and L respectively; the marks of the solid material inlet, solid material outlet, pyrolysis gas outlet, flue gas inlet, and flue gas outlet of the sludge carbonization furnace are M, N, O, P, and Q respectively, and the marks of the pyrolysis gas inlet and flue gas outlet of the pyrolysis gas combustion furnace are R and S respectively; XX is the sludge transfer vehicle.

[0052] Note: In this embodiment, the moisture content refers to the mass fraction.

[0053] In this embodiment, the sludge dryer, sludge carbonization furnace, pyrolysis gas combustion furnace, etc. are all existing products.

[0054] In this embodiment, the first heat exchanger can adopt a plate heat exchanger, and the second heat exchanger can adopt a regenerative heat exchanger.

[0055] Preferably, in this embodiment, the sludge dryer can adopt a sludge drying device in the form of a fluidized bed or a rotary kiln (both of which belong to the prior art), which can ensure uniform heating of the sludge in the high-temperature zone and improve the pyrolysis efficiency of the organic components.

[0056] Specifically, the sludge dryer used in this embodiment is a horizontal internal-heat rotary drying device, which mainly consists of a rotary cylinder, a feeding system (kiln head), a discharging system (kiln tail), a transmission device, a supporting device (bracket) and a sealing ring, etc. (belonging to the prior art). The sludge moves from the kiln head to the kiln tail in the sludge dryer, and is continuously lifted and sprinkled during the movement, so as to fully contact with the carrier gas until it is dried and discharged. In this embodiment, the sludge with a water content of 60 wt% is continuously and efficiently heat-exchanged with the carrier gas in the rotary cylinder of the sludge dryer, and the water content of the sludge is reduced from 60 wt% to 20 - 30 wt%. The temperature of the carrier gas decreases after passing through the sludge dryer (and the humidity gradually increases), and the sludge gradually forms fine particles in the sludge dryer (the specific surface area increases), thereby improving the drying efficiency. In addition, the fine sludge particles will rotate at a high speed in the sludge dryer, and they can form a thin film on the surface of the incoming sludge, reducing the viscosity of the sludge and completely solving the phenomenon that the sludge is easy to stick to the wall when it first enters, and improving the drying efficiency again and reducing the energy consumption.

[0057] The inner walls of the pipelines used in this embodiment can be subjected to anti-corrosion treatment (mainly by coating an anti-corrosion coating on the inner walls of the pipelines). Since the pyrolysis gas during the pyrolysis process of the sludge may contain various corrosive pollutants (such as SOx, NOx), which have strong corrosion ability, if not properly treated, it is easy to cause premature aging of the ventilation pipelines.

[0058] Of course, before the tail gas enters the tail gas treatment station in this embodiment, the waste heat in the tail gas can also be recycled (such as using the recycled waste heat in the tail gas to preheat the incoming sludge or for other processes in the factory area that require heat energy), so as to realize the recovery and utilization of heat to a greater extent.

[0059] Example 2

[0060] Such as Figure 4 And Figure 5As shown in the figure, this embodiment provides a sludge pyrolysis system, which includes a first scraper conveyor 200, a sludge pretreatment station 300, and the sludge pyrolysis assembly 100 as described in Embodiment 1. There are two sludge pretreatment stations 300. The sludge outlets of the two sludge pretreatment stations 300 are both connected to the solid material inlet of the sludge dryer 1 through the first scraper conveyor 200. The two sludge pretreatment stations 300 are respectively a first sludge pretreatment station 300a and a second sludge pretreatment station 300b. The first sludge pretreatment station 300a is used to perform pre-dehydration treatment on the incoming wet sludge, and the second sludge pretreatment station 300b is used to crush the incoming semi-dry sludge. In this way, the treatment can be selected from the first sludge pretreatment station or the second sludge pretreatment station according to the moisture content of the transported sludge. The sludge with a high moisture content is treated by the first sludge pretreatment station, and the sludge with a low moisture content is treated by the second sludge pretreatment station.

[0061] In the above technical solution, the first sludge pretreatment station 300a includes a wet sludge bin 301, a sludge pump 302, a sludge metering bin 303, a modification mixer 304, a high-pressure belt type deep dehydrator 305, a lime storage tank 306, and an iron salt storage tank 307. The wet sludge bin 301, the sludge pump 302, the sludge metering bin 303, the modification mixer 304, and the high-pressure belt type deep dehydrator 305 are connected in sequence. Both the lime storage tank 306 and the iron salt storage tank 307 are connected to the modification mixer 304. The sludge outlet of the high-pressure belt type deep dehydrator 305 is connected to the feed inlet of the first scraper conveyor 200. The wet sludge with a moisture content of 80 - 83% is transported to the wet sludge bin for transfer and storage by a sludge transport vehicle, and the sludge is lifted to the sludge metering bin by a sludge pump; the sludge in the sludge metering bin is sent to the modification mixer to be mixed and modified with lime and iron salt (using chemical methods and electrochemistry methods to condition and modify the sludge) to improve the sludge dehydration performance; the modified sludge is evenly distributed on the filter belt of the high-pressure belt type deep dehydrator for continuous pressure filtration to produce a sludge cake with a moisture content of about 60%. Such sludge meets the treatment requirements of the sludge pyrolysis assembly (the first sludge pretreatment station is applicable to some manufacturers who do not have a plate and frame filter press, so the directly transported sludge has a high moisture content and needs to be pre-dehydrated to meet the treatment requirements of the sludge pyrolysis assembly).

[0062] In the above technical solution, the second sludge pretreatment station 300b includes a mud cake silo 308, a second scraper conveyor 309 and a sludge crusher 310 connected in sequence. The sludge outlet of the sludge crusher 310 is connected to the feed port of the first scraper conveyor 200. If the moisture content of the transferred sludge is about 60%, it can be directly crushed into particles and processed by the sludge pyrolysis assembly (the second sludge pretreatment station is suitable for some manufacturers who are pre-installed with a plate and frame filter press, so the mud cake transported is pre-dried, and the moisture content of the mud cake can meet the processing requirements of the sludge pyrolysis assembly, but it is in block form and needs to be crushed in advance to be better processed by the sludge dryer).

[0063] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. Sludge pyrolysis assembly, characterized in that: The invention comprises a sludge dryer (1), a sludge carbonization furnace (2), a pyrolysis gas combustion furnace (3), a first heat exchanger (4), a second heat exchanger (5) and a condenser (6), wherein the sludge dryer (1) and the sludge carbonization furnace (2) both have a solid material inlet and a solid material outlet, the sludge dryer (1) also has a carrier gas inlet and a carrier gas outlet, the sludge carbonization furnace (2) has a pyrolysis gas outlet and a heating jacket (21), and the heating jacket (21) has a smoke inlet and a smoke outlet, and the pyrolysis gas combustion furnace (3) has a pyrolysis gas inlet and a smoke outlet. The solid material outlet of the sludge dryer (1) is connected to the solid material inlet of the sludge carbonization furnace (2), the pyrolysis gas outlet of the sludge carbonization furnace (2) is connected to the pyrolysis gas inlet of the pyrolysis gas combustion furnace (3), and the smoke outlet of the pyrolysis gas combustion furnace (3) is connected to the smoke inlet of the heating jacket (21); the carrier gas outlet of the sludge dryer (1) is connected to the heat medium inlet of the first heat exchanger (4), the heat medium outlet of the first heat exchanger is connected to the refrigerant inlet of the first heat exchanger (4) through the condenser (6), and the first The refrigerant outlet of the heat exchanger (4) is connected to the refrigerant inlet of the second heat exchanger (5), the refrigerant outlet of the second heat exchanger (5) is connected to the carrier gas inlet of the sludge dryer (1), the flue gas outlet of the heating jacket (21) is connected to the heat medium inlet of the second heat exchanger (5), and the condenser (6) is used to cool and dehumidify the drying carrier gas passing through it; it also includes a dust collector (8), the dust collector (8) is arranged at the connection between the carrier gas outlet of the sludge dryer (1) and the heat medium inlet of the first heat exchanger (4); it also includes a circulating A fan (9), wherein the circulating fan (9) is arranged at the connection point between the condenser (6) and the refrigerant inlet of the first heat exchanger (4), and is used to pump the carrier gas after dehumidification of the condenser (6) into the refrigerant channel of the first heat exchanger (4); and further comprising an exhaust gas treatment station (7), wherein the heat medium outlet of the second heat exchanger (5) is connected to the exhaust gas inlet of the exhaust gas treatment station (7), and the heat medium outlet of the first heat exchanger (4) is connected to the exhaust gas inlet of the exhaust gas treatment station (7) or to the pyrolysis gas inlet of the pyrolysis gas combustion furnace (3).

2. The sludge pyrolysis assembly according to claim 1, characterized in that: It also comprises a high-temperature fan (10), wherein the air inlet of the high-temperature fan (10) is connected to the smoke outlet of the heating jacket (21), and the air outlet of the high-temperature fan (10) is connected to the carrier gas inlet of the sludge dryer (1).

3. The sludge pyrolysis assembly according to claim 1, characterized in that: It also comprises a sludge charcoal bin (11), and the solid material outlet of the sludge carbonization furnace (2) is connected to the sludge charcoal bin (11) via a screw feeder (12).

4. The sludge pyrolysis assembly according to any one of claims 1 to 3, characterized in that: It also includes a urea storage tank (13) for supplying urea liquid to the pyrolysis gas combustion furnace (3).

5. Sludge pyrolysis system, characterized in that: The invention comprises a first scraper conveyor (200), a sludge pretreatment station (300) and a sludge pyrolysis assembly (100) according to any one of claims 1 to 4, wherein two sludge pretreatment stations (300) are provided, and the sludge outlets of the two sludge pretreatment stations (300) are both connected to the solid material inlet of the sludge dryer (1) through the first scraper conveyor (200), and the two sludge pretreatment stations (300) are respectively a first sludge pretreatment station (300a) and a second sludge pretreatment station (300b), wherein the first sludge pretreatment station (300a) is used for pre-dehydrating the delivered wet sludge, and the second sludge pretreatment station (300b) is used for crushing the delivered semi-dry sludge.

6. The sludge pyrolysis system according to claim 5, characterized in that: The first sludge pretreatment station (300a) comprises a wet sludge silo (301), a sludge pump (302), a sludge metering silo (303), a modified mixer (304), a high-pressure belt-type deep dehydrator (305), a lime storage tank (306) and an iron salt storage tank (307); the wet sludge silo (301), the sludge pump (302), the sludge metering silo (303), the modified mixer (304) and the high-pressure belt-type deep dehydrator (305) are connected in sequence; the lime storage tank (306) and the iron salt storage tank (307) are both connected to the modified mixer (304); and the sludge outlet of the high-pressure belt-type deep dehydrator (305) is connected to a feed port of the first scraper conveyor (200).

7. The sludge pyrolysis system according to claim 5, characterized in that: The second sludge pretreatment station (300b) comprises a sludge cake silo (308), a second scraper conveyor (309) and a sludge crusher (310) which are connected in sequence, and the sludge outlet of the sludge crusher (310) is connected to the feed inlet of the first scraper conveyor (200).

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