CN210736521U

CN210736521U - Sludge drying system

Info

Publication number: CN210736521U
Application number: CN201921384942.9U
Authority: CN
Inventors: 王志玺; 单明焕; 魏晓东; 朱伟娜; 柳永盛; 赵强; 马淑叶
Original assignee: ANYANG AIERWANG NEW ENERGY ENVIRONMENTAL CO LTD
Current assignee: Henan aierwang new energy and environment Co.,Ltd.
Priority date: 2019-08-23
Filing date: 2019-08-23
Publication date: 2020-06-12
Anticipated expiration: 2029-08-23

Abstract

The utility model discloses a sludge drying system. This sludge drying system includes: a sludge bin; the mixing device is provided with a first sludge inlet, a second sludge inlet and a sludge mixing outlet, and the first sludge inlet is connected with the sludge bin; the sludge drying machine is internally provided with a forming device and is provided with a sludge mixing inlet, a dried and formed sludge outlet, an inert gas inlet and an inert gas outlet, and the sludge mixing inlet is connected with the sludge mixing outlet; the sorting device is provided with a drying forming sludge inlet, a first dry material outlet and a second dry material outlet, the drying forming sludge inlet is connected with the drying forming sludge outlet, and the second dry material outlet is connected with the second sludge inlet. The sludge drying system has the advantages of high treatment capacity, convenience in adjusting the water content of the outlet sludge, low energy consumption, no addition and no pollution, can realize sludge reduction, harmless and recycling treatment, and the outlet sludge can meet the requirement of sludge recycling.

Description

Sludge drying system

Technical Field

The utility model relates to a sludge drying handles technical field, particularly, the utility model relates to a sludge drying system.

Background

Along with the acceleration of the urbanization process in China, the urban sewage treatment rate is gradually improved, and the total sludge amount of the urban sewage treatment plant is also increased rapidly. According to the introduction of research data, the sludge yield of the municipal sewage treatment plant in China is increased at a growth rate of 4% in the next 3 years. It is expected that 6000 million tons of sludge will be produced annually by the year 2020. The water content of the sludge of the sewage treatment plant is usually about 80% after the sludge is preliminarily dehydrated, the volume is large, the sludge is not favorable for transportation and treatment, the sludge is easy to decay, the odor is large, and the environmental safety is seriously damaged.

At present, domestic sludge of sewage plants in China is mainly landfilled in garbage, and is very deficient in the aspect of comprehensive utilization of resources after sludge reduction, stabilization and innocent treatment. With the continuous improvement of the sewage treatment rate, a great amount of sludge is filled into the landfill to bring huge burden to the landfill site, and the landfill site is more and more limited.

Whether the sludge is buried, or is burnt or recycled, strict requirements are imposed on indexes such as water content and the like. The sludge water content of the sludge for mixed landfill of the sludge treatment of the urban sewage treatment plant (GBT23485-2009) is required to be less than 60 percent; sludge for landscaping in sludge treatment of urban sewage treatment plants (GBT23486-2009) requires that the water content of the sludge is less than 40 percent; sludge for separate incineration of sludge disposal in urban sewage treatment plants (GBT24602-2009) requires that the water content of sludge subjected to self-sustaining incineration is less than 50%, and the low-temperature heat value is greater than 5000 kJ/kg; the sludge for brick making by sludge treatment in urban sewage treatment plants (GBT23485-2009) requires that the water content of the sludge is less than 40 percent.

After the sludge is dehydrated and dried, the water content is reduced, the volume is reduced by about 4-5 times, the residual substances after drying are relatively stable, the malodorous substances and pathogenic organisms are greatly removed, and the heat value and the nutritional ingredients of the sludge are reserved. Therefore, it can be said that sludge drying is the prerequisite and key of sludge treatment and disposal technology. Sludge dewatering and drying can be divided into: natural drying, mechanical dehydration and heat drying. The natural drying is restricted by factors such as climate, field and the like, and basically cannot adapt to the current day with increasing sludge amount; mechanical dehydration, because the moisture content of the discharged sludge is high, the water-containing requirement of the existing sludge terminal treatment cannot be met, and the sludge can only be used as pretreatment before sludge heat drying; the heat drying has the advantages of high efficiency, large treatment capacity, high automation degree and the like, and is the main development direction of the sludge drying and dewatering technology in the future.

In the research and development of sludge treatment technology, the phenomena of 'heavy equipment and light process' generally exist. Therefore, although there are many different treatment processes for sludge heat drying, the difference of the treatment processes mainly lies in the difference of sludge drying equipment, and the overall comprehensive energy consumption is not greatly different. In order to further reduce the heat consumption of sludge treatment, a new process route needs to be developed besides adopting efficient sludge drying equipment to enhance the systematicness of the sludge heat drying process.

At present, the sludge heat drying can be carried out by low-temperature drying and high-temperature drying according to the operating process temperature. The low-temperature drying is generally operated under micro-negative pressure, a large amount of low-temperature circulating gas is adopted to directly contact with the sludge, and the moisture is taken away by mainly utilizing the unsaturation degree of water vapor in dry air, so that the sludge drying is realized. At present, a low-temperature drying process is generally coupled with a heat pump technology, and a belt type drying machine is adopted to directly dry sludge by low-temperature air. The main disadvantages of this process are: the drying temperature is low, and the sludge can not be sterilized; the belt type drying efficiency is low; the heat pump converts electricity into heat or cold to heat or cool the dried air, which causes energy waste. The high-temperature drying mainly depends on absorbing heat to evaporate water, the operating temperature is about 100 ℃, the operating pressure is normal pressure or micro negative pressure, indirect drying equipment is adopted, and a plurality of heat sources can be utilized, such as waste heat steam, heat conduction oil, hot flue gas, natural gas and the like. Sludge high-temperature heat drying: the temperature is high, and the sludge can be sterilized; the heat source is wide, and the device is suitable for being matched with industrial parks, thermal power plants, biogas plants and the like. However, the existing sludge high-temperature heat drying process also has some disadvantages: small processing capacity, high energy consumption, insufficient waste heat recovery, low system safety and the like. Therefore, it is required to develop a sludge drying process with high treatment capacity, low energy consumption and high safety.

SUMMERY OF THE UTILITY MODEL

The present invention aims at solving at least one of the technical problems in the related art to a certain extent. Therefore, the utility model discloses an aim at propose sludge drying system. The sludge drying system has the advantages of high treatment capacity, convenience in adjusting the water content of the outlet sludge, low energy consumption, no addition and no pollution, can realize sludge reduction, harmless and recycling treatment, and the outlet sludge can meet the requirement of sludge recycling.

In one aspect of the present invention, the utility model provides a sludge drying system. According to the utility model discloses an embodiment, this sludge drying system includes: a sludge bin; the mixing device is provided with a first sludge inlet, a second sludge inlet and a sludge mixing outlet, and the first sludge inlet is connected with the sludge bin; the sludge drying machine is internally provided with a forming device and is provided with a sludge mixing inlet, a dried and formed sludge outlet, an inert gas inlet and an inert gas outlet, and the sludge mixing inlet is connected with the sludge mixing outlet; and the sorting device is provided with a drying forming sludge inlet, a first dry material outlet and a second dry material outlet, the drying forming sludge inlet is connected with the drying forming sludge outlet, and the second dry material outlet is connected with the second sludge inlet.

According to the utility model discloses sludge drying system at first supplies with pending mud in the mud feed bin to the compounding device in with the sludge drier mix, gained mud compounding gets into sludge drying machine, carries out the mummification dehydration in the inert gas atmosphere to form the particle shape under forming device's effect, obtain mummification shaping mud. And further, the dried and formed sludge enters a sorting device to be sorted according to a certain specification, a part of dry sludge is returned to the mixing device to be mixed with the sludge to be treated, and the other part of dry sludge can be used as an outlet dry material to be recycled. From this, the utility model provides a sludge drying system single line, single set throughput are greater than 120t/d, can handle the mud that contains water about 80%, and the moisture content of export mud can be adjusted according to mud end use, and the sludge drying system adopts the inert gas atmosphere, and the security is high, does not have the explosion hidden danger. Additionally, the utility model discloses an except containing a small amount of flocculating agent in the product that the sludge drying system handled and obtain, do not add other medicaments, export the drier and can realize land use, also can be used to burn uses such as carbomorphism, brickmaking, the utility model discloses a sludge drying system can realize innoxious, minimizing, the resourceful treatment requirement of mud completely.

Optionally, the sludge drying system further comprises: and the sludge pump is connected with the sludge bin.

Optionally, a conveyor is arranged between the sludge bin and the first sludge inlet.

Optionally, an insulating layer is arranged outside the sludge drying machine.

Optionally, the sludge drying system further comprises: and the preheating conveying device is arranged between the drying forming sludge outlet and the drying forming sludge inlet and is connected with the inert gas inlet.

Optionally, a lifter is arranged between the preheating conveying device and the drying formed sludge inlet.

Optionally, the sludge drying system further comprises: the waste heat recovery device is provided with a high-temperature medium inlet and a low-temperature medium outlet, and the high-temperature medium inlet is connected with the inert gas outlet; the gas-liquid separation device is provided with a low-temperature medium inlet, a gas outlet and a liquid outlet, the low-temperature medium inlet is connected with the low-temperature medium outlet, and the gas outlet is connected with the preheating conveying device.

Optionally, a gas detector is arranged between the high-temperature medium inlet and the inert gas outlet.

Optionally, a circulating fan is arranged between the gas outlet and the preheating conveying device.

Optionally, the sludge drying system further comprises: and the dry material bin is connected with the first dry material outlet, and a conveyor is arranged between the dry material bin and the first dry material outlet.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural view of a sludge drying system according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a sludge drying system according to another embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In one aspect of the present invention, the utility model provides a sludge drying system. According to the embodiment of the present invention, referring to fig. 1, the sludge drying system comprises: the device comprises a sludge bin 10, a mixing device 20, a sludge drier 30 and a sorting device 40. The mixing device 20 is provided with a first sludge inlet 21, a second sludge inlet 22 and a sludge mixing outlet 23, and the first sludge inlet 21 is connected with the sludge bin 10; a forming device 31 is arranged in the sludge drier 30, the sludge drier 30 is provided with a sludge mixing inlet 32, a drying formed sludge outlet 33, an inert gas inlet 34 and an inert gas outlet 35, and the sludge mixing inlet 32 is connected with the sludge mixing outlet 23; the sorting device 40 is provided with a dried formed sludge inlet 41, a first dry material outlet 42 and a second dry material outlet 43, the dried formed sludge inlet 41 is connected with the dried formed sludge outlet 33, and the second dry material outlet 43 is connected with the second sludge inlet 22.

According to the utility model discloses sludge drying system at first supplies with pending mud in the mud feed bin to the compounding device in with the sludge drier mix, gained sludge compounding gets into sludge drying machine, carries out the mummification dehydration in inert gas (for example nitrogen gas and/or argon gas) atmosphere to form the particle shape under forming device's effect, obtain mummification shaping mud. And further, the dried and formed sludge enters a sorting device to be sorted according to a certain specification, a part of dry sludge is returned to the mixing device to be mixed with the sludge to be treated, and the other part of dry sludge can be used as an outlet dry material to be recycled. From this, the utility model provides a sludge drying system single line, single set throughput are greater than 120t/d, can handle the mud that contains water about 80%, and the moisture content of export mud can be adjusted according to mud end use, and the sludge drying system adopts the inert gas atmosphere, and the security is high, does not have the explosion hidden danger. Additionally, the utility model discloses an except containing a small amount of flocculating agent in the product that the sludge drying system handled and obtain, do not add other medicaments, export the drier and can realize land use, also can be used to burn uses such as carbomorphism, brickmaking, the utility model discloses a sludge drying system can realize innoxious, minimizing, the resourceful treatment requirement of mud completely.

The sludge drying system according to the embodiment of the present invention is further described in detail with reference to fig. 1-2.

According to the utility model discloses an embodiment, compounding device 20 has first mud entry 21, second mud entry 22 and mud compounding export 23, and first mud entry 21 links to each other with mud feed bin 10. The mixing device 20 is suitable for mixing the sludge to be treated from the sludge bin 10 with the dry sludge from the sorting device 40 to obtain a sludge mixture. The inventor finds that the subsequent drying and forming effect of the sludge to be treated can be obviously improved by mixing the sludge to be treated with the water content of about 80% with the drying and forming sludge output by the sorting device, so that the treatment efficiency of a subsequent sludge drying machine and the quality of the drying and forming sludge are obviously improved. In addition, the mixing ratio of the sludge to be treated and the sludge dry material is not particularly limited, and may be adjusted according to the water content required for the end use of the export sludge.

According to the utility model discloses an embodiment is equipped with forming device 31 in the sludge drying machine 30, and sludge drying machine 30 has mud compounding entry 32, mummification shaping sludge outlet 33, inert gas entry 34 and inert gas export 35, and mud compounding entry 32 links to each other with mud compounding export 23. The sludge drier 30 is adapted to dry and form the sludge mixture in an inert gas atmosphere to obtain the dried and formed sludge in a particle shape. Specifically, the sludge drier may dehydrate and dry the sludge mixture by using external heat (as shown in a in fig. 1 and 2), and the specific type of the external heat is not particularly limited, and may be, for example, high-temperature steam, high-temperature heat transfer oil, high-temperature flue gas, and the like. Meanwhile, the forming device in the sludge drying machine can carry out forming treatment on the sludge mixed material. Therefore, the sludge drying machine collaborative forming device can utilize external heat to realize the functions of dewatering, drying, transporting, mixing, stirring, forming and the like of the sludge.

According to the utility model discloses an embodiment, sorting unit 40 has mummification shaping sludge inlet 41, first drier export 42 and second drier export 43, and mummification shaping sludge inlet 41 links to each other with mummification shaping sludge outlet 33, and second drier export 43 links to each other with second sludge inlet 22. The sorting device is suitable for sorting the dried and formed sludge according to a certain specification so as to obtain a first dry material and a second dry material, wherein the first dry material can be used as an outlet dry material for resource utilization, and the second dry material is returned to the mixing device to be mixed with the sludge to be treated. Specifically, the sorting device can sort the dried sludge according to the particle size to obtain a first dry material with the particle size of more than or equal to 6mm and a second dry material with the particle size of less than 6 mm.

According to the embodiment of the present invention, referring to fig. 2, the sludge drying system further comprises: a sludge pump 50. The sludge pump 50 is connected to the sludge silo 10. Therefore, the sludge pump 50 can be used for supplying the sludge to be treated to the sludge bin 10 for temporary storage, thereby further improving the production continuity.

According to the embodiment of the present invention, a conveyor 60 is provided between the sludge storage bin 10 and the first sludge inlet 21. In addition, according to the embodiment of the present invention, a conveyor 60 is also disposed between the second dry material outlet 43 and the second sludge inlet 22. Thereby, the conveyor 60 can be used for supplying the sludge to be treated in the sludge bin 10 to the mixing device 20 and returning the part of the dry sludge separated by the separation device 40 to the mixing device 20.

According to the embodiment of the present invention, the heat insulating layer 36 is disposed outside the sludge drying machine 30. Therefore, the heat loss in the sludge drying machine 30 can be effectively reduced, and the utilization rate of heat in the sludge drying machine 30 is further improved.

According to the embodiment of the present invention, referring to fig. 2, the sludge drying system further comprises: the conveyor 70 is preheated. The preheating conveying device 70 is arranged between the drying formed sludge outlet 33 and the drying formed sludge inlet 41 and is connected with the inert gas inlet 34. The preheating conveying device 70 can preheat the inert gas sent by the subsequent gas-liquid separation device by using the heat carried by the dried formed sludge while conveying the dried formed sludge, and then the preheated inert gas enters the sludge drying machine 30, so that the overall thermal efficiency of the system can be further improved.

According to the utility model discloses an embodiment, preheat conveyor 70 and connect towards mummification shaping sludge outlet 33 direction slope to mummification shaping sludge discharge.

According to the embodiment of the present invention, referring to fig. 2, a lifting machine 80 is provided between the preheating conveying device 70 and the drying and forming sludge inlet 41.

According to the embodiment of the present invention, referring to fig. 2, the sludge drying system further comprises: the waste heat recovery device 90 and the gas-liquid separation device 100. The waste heat recovery device 90 is provided with a high-temperature medium inlet 91 and a low-temperature medium outlet 92, wherein the high-temperature medium inlet 91 is connected with the inert gas outlet 35; the gas-liquid separation device 100 has a low-temperature medium inlet 101, a gas outlet 102 and a liquid outlet 103, the low-temperature medium inlet 101 is connected with the low-temperature medium outlet 92, and the gas outlet 102 is connected with the preheating conveying device 70. The high-temperature inert gas discharged from the sludge drying machine 30 enters the waste heat recovery device 90 for waste heat recovery treatment, and the obtained heat (shown as B in fig. 2) can be applied to other production units. The inert gas after waste heat recovery is discharged from the low-temperature medium outlet 92, and further enters the gas-liquid separation device 100 for gas-liquid separation treatment, the separated gas returns to the preheating conveying device 70, and is preheated by the dried formed sludge, and the separated liquid (the main component is water, as shown in fig. 2C) can be applied to other production systems. Therefore, the utility model discloses a sludge drying system preheats conveyor 70, waste heat recovery device 90 and gas-liquid separation device 100 through the setting, can further make the system waste heat obtain abundant recovery, has effectively reduced sludge drying's energy consumption, and retrieves the waste heat that obtains and can be used for other production units.

According to an embodiment of the present invention, referring to fig. 2, a gas detector 110 is provided between the high temperature medium inlet 91 and the inert gas outlet 35. The gas detector 110 is adapted to monitor the inert gas component discharged from the sludge drying machine 30 and respond to the change of the inert gas component in time to ensure that the inside of the sludge drying machine 30 is in an inert gas atmosphere.

According to an embodiment of the present invention, referring to fig. 2, a circulation fan 120 is provided between the gas outlet 102 and the preheating conveying device 70. The circulation fan 120 is adapted to supply the gas discharged from the gas-liquid separation device 100 to the preheating conveyor 70.

According to the embodiment of the present invention, referring to fig. 2, the sludge drying system further comprises: a dry stock bin 130. The dry material bin 130 is connected to the first dry material outlet 42, and a conveyor 60 is provided between the dry material bin 130 and the first dry material outlet 42. The dry material bin 130 is adapted to store a portion of the sludge dry material sorted by the sorting device 40.

For convenience of understanding, a sludge drying method implemented by using the sludge drying system according to an embodiment of the present invention will be described below.

The sludge pump is used for conveying sludge with the moisture content of about 80% from the outside to the sludge bin, and then the sludge enters the mixing device and dry materials conveyed by the sorting device to be mixed; the mixed materials enter a sludge drier to be heated and dehydrated to reach the required water content and form a granular shape; the dry materials at the outlet of the sludge drier are sent to a lifting device by a preheating conveying device; in the preheating conveying device, the high-temperature materials can also be heated to enter the inert gas of the sludge drying machine, so that the energy consumption is further reduced; the lifting device sends the dry materials into a sorting device to separate the materials according to a certain specification; the discharge conveyor conveys the materials meeting the requirements into the dry material bin, and the circulating conveyor conveys the materials which do not meet the requirements into the material mixing device to be mixed with the sludge output by the sludge bin; in order to monitor the inert condition in the drier, a gas detector is additionally arranged on a steam pipeline at the outlet of the sludge drier, then the steam enters a waste heat recovery device to recover the heat in the steam, and the part of heat is used for other heat using units; after the inert gas with the heat recovered is treated by the gas-liquid separation device, the inert gas is sent into the sludge drier again through the circulating fan for recycling; the condensate and the separated water are sent to other production systems for use.

The sludge drying system according to the embodiment of the utility model can have at least one of the following advantages:

(1) single line and single set processing capacity is large, and the processing capacity is larger than 120 t/d;

(2) the sludge with water content of about 80% can be treated, and the water content of the outlet sludge can be adjusted according to the terminal use of the sludge;

(3) the waste heat is fully recovered, and the waste heat recovery system can be used for other production units, so that the energy consumption of sludge drying is effectively reduced;

(4) the inert atmosphere is adopted, so that the safety is high, and the potential explosion hazard is avoided;

(5) the dried sludge product contains a small amount of flocculant and is not added with any medicament, the dry material at the outlet can realize land utilization, and can be incinerated, carbonized, brickmaking and the like, thereby completely realizing the requirements of harmlessness, reduction and reclamation of the sludge.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims

1. A sludge drying system, comprising:

a sludge bin;

the mixing device is provided with a first sludge inlet, a second sludge inlet and a sludge mixing outlet, and the first sludge inlet is connected with the sludge bin;

the sludge drying machine is internally provided with a forming device and is provided with a sludge mixing inlet, a dried and formed sludge outlet, an inert gas inlet and an inert gas outlet, and the sludge mixing inlet is connected with the sludge mixing outlet;

the sorting device is provided with a drying forming sludge inlet, a first dry material outlet and a second dry material outlet, the drying forming sludge inlet is connected with the drying forming sludge outlet, and the second dry material outlet is connected with the second sludge inlet.

2. The sludge drying system of claim 1, further comprising:

and the sludge pump is connected with the sludge bin.

3. The sludge drying system of claim 1, wherein a conveyor is disposed between the sludge bin and the first sludge inlet.

4. The sludge drying system of claim 1, wherein an insulating layer is arranged outside the sludge drying machine.

5. The sludge drying system of claim 1, further comprising:

and the preheating conveying device is arranged between the drying forming sludge outlet and the drying forming sludge inlet and is connected with the inert gas inlet.

6. The sludge drying system of claim 5, wherein a lifter is disposed between the preheating conveyor and the dried sludge inlet.

7. The sludge drying system of claim 5, further comprising:

the waste heat recovery device is provided with a high-temperature medium inlet and a low-temperature medium outlet, and the high-temperature medium inlet is connected with the inert gas outlet;

the gas-liquid separation device is provided with a low-temperature medium inlet, a gas outlet and a liquid outlet, the low-temperature medium inlet is connected with the low-temperature medium outlet, and the gas outlet is connected with the preheating conveying device.

8. The sludge drying system of claim 7, wherein a gas detector is disposed between the high temperature medium inlet and the inert gas outlet.

9. The sludge drying system of claim 7, wherein a circulation fan is disposed between the gas outlet and the preheating conveying device.

10. The sludge drying system of any one of claims 1 to 9, further comprising:

and the dry material bin is connected with the first dry material outlet, and a conveyor is arranged between the dry material bin and the first dry material outlet.