A municipal sludge drying system

Abstract

A municipal sludge drying system outputs sludge with a low moisture content to a first mechanical dewatering device for dewatering through the structural design of a pyrolysis water tank. At the bottom of the sludge hydrothermal hydrolysis tank, the wet sludge that cannot be quickly heated due to depth is directly pumped to a second mechanical dewatering device for dewatering, forming sludge with a relatively high moisture content. The co-firing Nick hot pressing forming device forms a mud shell by hot pressing coal powder and wood chips in equal proportions, and injects wet sludge into the mud shell for hot pressing, maximizing the utilization of a small amount of sludge from hydrothermal hydrolysis and mixing to form a large amount of composite sludge blocks.

Description

Technical Field

[0001] The present invention relates to the technical field of sludge incineration, and particularly relates to a municipal sludge drying system. Background Art

[0002] As a by-product of sewage treatment, in recent years, with the increase in sewage treatment volume and treatment standards, the output of sludge has increased sharply. Wet sludge landfill is the most commonly used method at present, but it must occupy a large amount of land resources, and often emits unpleasant odors. If not properly treated, it may also pollute groundwater, spread infectious diseases, etc.; Incineration is one of the effective methods for volume reduction and harmless treatment of sludge, but there are also certain drawbacks. For example, small-scale incinerators such as fluidized bed boilers, bubbling fluidized beds, grate furnaces, and circulating fluidized beds have problems such as low thermal efficiency, high fan power, high dust content, incomplete combustion, and difficult ignition; especially when the water content of sludge is too high, it causes incomplete combustion in the pyrolysis gasification furnace.

[0003] The process of municipal sludge drying is the process of water evaporation from wet sludge. The water in the sludge is classified into free water, interstitial water, surface adsorbed water, and bound water according to its existence form. Free water is the water outside the sludge particles, accounting for about 65-85% of the total water content. There is no direct connection between it and the sludge particles, and it is easy to be removed; Interstitial water accounts for about 10-25%. It is the water contained in the gaps between sludge flocs. Due to the surface tension, it cannot flow freely on the sludge particles. To separate it, strong mechanical force must be used; The proportion of surface adsorbed water and bound water is about 10%. They are the water bound to the extracellular polymeric substances (EPS) or the surface of the particles, as well as the water inside the particles or cells respectively. Traditional mechanical dewatering is difficult to work, and usually, EPS and cells need to be destroyed to release the water for removal. Due to the complex water existence form and structural characteristics of sludge, it is extremely difficult to remove its water. Research shows that the difficulty of sludge dewatering mainly lies in the encapsulation effect of EPS and the high compressibility of sludge.

[0004] Regarding the problem of sludge EPS encapsulation, the effective means reported in domestic and foreign literature mainly include hydrothermal hydrolysis, acid-base conditioning, ultrasonic waves, freeze-thaw, advanced oxidation, biological leaching, enzyme treatment, etc. Among them, hydrothermal hydrolysis has received wide attention due to its characteristics such as no need to add chemical agents, ability to utilize waste heat, and high dehydration efficiency. Hydrothermal hydrolysis is to directly place high-moisture-content sludge in a closed inert environment, carry out hydrolysis reaction at a certain temperature (60-250°C) and autogenous pressure, destroy EPS, convert bound water and surface adsorbed water into other water, and improve the solid-liquid separation performance. After treatment at 180-210°C for 60 minutes, the water content of 6MPA hot-pressed dehydrated sludge is reduced to 30%.

[0005] For the problem of sludge EPS encapsulation, the effective means reported in domestic and foreign literature mainly include hydrothermal hydrolysis, acid-base conditioning, ultrasonic waves, freeze-thaw, advanced oxidation, biological leaching, enzyme treatment, etc. Among them, hydrothermal hydrolysis has received wide attention due to its characteristics such as no need to add chemical agents, ability to utilize waste heat, and high dehydration efficiency. Hydrothermal hydrolysis is to directly place high-moisture-content sludge in a closed inert environment, carry out hydrolysis reaction at a certain temperature (60-250°C) and autogenous pressure, destroy EPS, convert bound water and surface adsorbed water into other water, and improve the solid-liquid separation performance. After treatment at 180-210°C for 60 minutes, the water content of 6MPA hot-pressed dehydrated sludge is reduced to 30%.

[0006] However, in actual production, a large amount of sludge is stored in the sludge warehouse. The experimental hot hydrolysis method cannot quickly heat the deep sludge, and the warehouse needs to rotate efficiently, continuously outputting sludge for dehydration and incineration to make room for subsequent sludge input. Therefore, under the limited plant area and time pressure, a solution that meets the requirements of large-scale sludge hot hydrolysis cannot be formed.

[0007] Moreover, the difference in sludge moisture content directly affects the in-furnace energy consumption parameters and emission parameters of the subsequent sludge incineration process.

[0008] Therefore, a production system that can maximize the sludge drying efficiency and improve the energy consumption utilization of sludge incineration needs to be designed. Summary of the Invention

[0009] In order to solve the above technical deficiencies, the present invention provides a municipal sludge drying system. The technical solution of the present invention: A municipal sludge drying system includes a sludge hot hydrolysis tank, a first mechanical dehydration device, a second mechanical dehydration device, an admixture-incinerated mud shell hot pressing and forming device, a wet and dry sludge perfusion hot pressing and forming device, and a sludge feeder; the sludge hot hydrolysis tank is a semi-underground sealed tank with a partition wall, which divides the sludge hot hydrolysis tank into a hot hydrolysis chamber and a sludge inlet chamber, and the sludge inlet chamber is provided with a sludge inlet channel;

[0010] Above the sludge liquid level in the hot hydrolysis chamber, there is a heating space, and a steam pipeline connected to the waste heat boiler system is laid in this heating space, and the steam pipeline is used to heat up and control the temperature of the heating space; a sludge scraping device is arranged in the heating space, and a sludge outlet channel is arranged on one side. The sludge scraping device circulates and scrapes the fully hot-hydrolyzed sludge in the heating space to the sludge outlet channel and outputs it to the first mechanical dehydration device for dehydration;

[0011] A wet sludge output pipeline is arranged at the bottom layer of the sludge hot hydrolysis tank, and the wet sludge at the bottom of the tank is pumped to the second mechanical dehydration device for dehydration; the admixture-incinerated mud shell hot pressing and forming device includes a pulverized coal and wood chip mixer and a hot pressing mold, and the hot pressing mold mixes and hot presses pulverized coal and wood chips with the sludge dehydrated by the first mechanical dehydration device into a cavity-containing mud shell;

[0012] The wet and dry sludge perfusion hot pressing and forming device injects the sludge dehydrated by the second mechanical dehydration device into the cavity-containing mud shell and hot presses it into an admixture-incinerated sludge briquette;

[0013] The sludge feeder inputs the admixture-incinerated sludge briquette into the incinerator.

[0014] With the above technical solution, in the actual sludge treatment production process, it is impossible to carry out long-term hydrothermal treatment on a large amount of sludge. Therefore, it is designed to carry out hydrothermal heat pressing dehydration on a small amount of sludge, mix it with pulverized coal and wood chips to form a cavity-bearing mud shell, improve the combustion performance of the outer shell, and then mechanically dehydrate a large amount of wet sludge and pour it into the cavity-bearing mud shell for hot pressing plasticity to form a sludge block. Due to the low moisture content of the outer cavity-bearing mud shell and the addition of pulverized coal and wood chips to improve the combustion performance of the mud shell, the outer cavity-bearing mud shell burns fully in the furnace, and the wet sludge inside is indirectly heated and dried by the combustion of the cavity-bearing mud shell. When the outer cavity-bearing mud shell burns out, the wet sludge inside has been further dried and its combustion performance has been improved. Under this effect, while improving the drying efficiency of a large amount of sludge, the combustion performance of the sludge is also improved. Thus, the problem of increased fuel consumption cost caused by directly inputting wet sludge is avoided.

[0015] Since only a small amount of sludge needs to be subjected to hydrothermal heat pressing dehydration, while a large amount of sludge is wet sludge dehydration, the overall efficient treatment of sludge is maintained.

[0016] The specific solution is as follows. The traditional sludge storage is changed to a semi-underground sealed hydrothermal hydrolysis pool. Through the liquid pressure balance between the sludge inlet chamber and the hydrothermal hydrolysis chamber separated by partitions, the sludge liquid level in the hydrothermal hydrolysis chamber is maintained at all times corresponding to the sludge outlet channel by the sludge inlet through the inlet channel. The heating space of the hydrothermal hydrolysis chamber is heated and temperature-controlled by the steam pipeline output from the waste heat boiler system, maintained between 180 and 210 °C. The sludge scraper runs regularly to scrape the fully hydrothermally hydrolyzed sludge on the liquid surface into the outlet channel, and then the new liquid surface continues the hydrothermal hydrolysis reaction in a cycle, and the sludge with low moisture content is output to the first mechanical dehydration equipment for dehydration.

[0017] At the bottom of the sludge hydrothermal hydrolysis pool, the wet sludge that cannot be quickly heated due to depth is directly pumped to the second mechanical dehydration equipment for dehydration to form sludge with a relatively high moisture content. Through proportional mixing and hot pressing, the small amount of sludge subjected to hydrothermal hydrolysis is maximally utilized to mix and form a large amount of composite sludge blocks.

[0018] The mechanical dehydration equipment is a conventional equipment, such as a flash dryer, a rotary dryer, etc.

[0019] The present invention is further configured as follows: the hot pressing forming equipment for the mixed fired mud shell comprises a first input pipe, a second input pipe, an electric rotating table and a plurality of groups of hot pressing mold mechanisms, the electric rotating table is provided with a plurality of groups of support arms along the radial direction of the rotation, the plurality of groups of hot pressing mold mechanisms are respectively fixedly connected with the plurality of groups of support arms, the hot pressing mold mechanisms comprise a left half-die, a right half-die, a hot pressing convex die, a horizontal track, a pair of horizontal cylinders and a vertical cylinder, the left half-die and the right half-die are respectively slidably engaged with the horizontal track, and are slidably assembled in the horizontal direction to form a complete die with a concave cavity, the pair of horizontal cylinders are fixedly connected with the horizontal track, and their piston rods are respectively connected with the left half-die and the right half-die to drive the left half-die and the right half-die to be assembled or separated; the horizontal track is fixedly connected with the support arm, and the support arm is provided with a bracket extending to the vertical upper side of the complete die;

[0020] The electric rotary table includes a starting station and an ending station, the first input pipe is connected to the first mechanical dewatering device to pump the dewatered sludge quantitatively into the complete concave mold at the starting station; the second input pipe is connected to the coal powder and sawdust mixer to quantitatively transport the coal powder and sawdust into the complete concave mold at the starting station;

[0021] The vertical cylinder is fixed on the bracket and cooperates with the hot pressing punch to drive the hot pressing punch in and out of the complete die to hot press into a mud shell with a cavity; the hot pressing punch, the left half die and the right half die are all provided with a heating unit.

[0022] By adopting the above technical scheme, the sludge dehydrated by the first mechanical dehydration equipment is quantitatively pumped into the complete concave mold of the starting station, the coal powder and wood chips are quantitatively transported into the complete concave mold of the starting station, and then the hot pressing punch is pressed down to close the mold with the complete concave mold, and the sludge, coal powder and wood chips are mixed and hot-pressed to form a cavity mud shell with a concave cavity.

[0023] The present invention is further configured as follows: the dry and wet sludge perfusion hot pressing molding equipment comprises a third input pipe, a first conveyor, a second conveyor and a plurality of sealing hot pressing mechanisms, the first conveyor is provided with a first conveyor belt, and the first and the second conveyors are connected with the complete concave mold of the termination station at the head and the tail, respectively, the first conveyor belt is located vertically below the complete concave mold, and is provided with a plurality of groups of guiding and positioning protrusions that fit the outer contour of the cavity mud shell, the left half concave surface and the right half concave mold are opened horizontally, the cavity mud shell falls into the guiding and positioning protrusions, and is transported to the second conveyor;

[0024] The second conveyor includes a second conveyor belt disposed vertically above the first conveyor belt and operates at the same synchronous frequency; the several sealing and hot pressing mechanisms are respectively fixed on the second conveyor belt corresponding to the spacing of several groups of guiding and positioning bumps. The sealing and hot pressing mechanism includes a sealing male mold, and the sealing male mold includes an end face adapted to the inner cavity opening of the mud shell with a cavity and several air column parts inserted into the inner cavity of the mud shell with a cavity. The sealing male mold rotates with the second conveyor belt wheel and merges with and separates from the inner cavity opening of the mud shell with a cavity;

[0025] The first conveyor belt transports the sealed mud shell with a cavity to the sludge feeder.

[0026] With the above scheme, the left half female mold and the right half female mold separate left and right along the horizontal track, and the mud shell with a cavity naturally falls onto the first conveyor belt and is transported to the lower part of the second conveyor belt. During the transportation process, the sludge with a higher moisture content dehydrated by the second mechanical dehydration equipment is quantitatively poured into the mud shell with a cavity. Along with the synchronous operation of the first and second conveyor belts, the sealing male mold arranged on the second conveyor belt merges with the mud shell with a cavity during operation, heat-seals the sludge with a higher moisture content in the mud shell with a cavity, uses the end face to hot-press the inner cavity opening surface of the mud shell with a cavity, and further dries the surface of the wet sludge by using heat and solidifies it in the mud shell with a cavity. At the same time, the arranged air column parts form several ventilation holes in the wet sludge, making the solidified sludge block have air holes, which can accelerate the drying of the wet sludge inside the mud shell with a cavity during subsequent incineration.

[0027] A further setting of the present invention: The hot pressing male mold, the left half female mold, the right half female mold, and the sealing male mold are all made of heat-conducting metal and are provided with electric heating modules inside.

[0028] A further setting of the present invention: The hot pressing male mold, the left half female mold, the right half female mold, and the sealing male mold are all made of heat-conducting metal and are provided with heat-conducting oil channels inside. The system further includes a heat-conducting oil heater, and the heater inputs heat-conducting oil into each mold.

[0029] With the above technical scheme, the sludge in the mold is heated and dried through an electric heating module such as an electric heating wire module or a hot oil channel.

[0030] A further setting of the present invention: The hydrothermal hydrolysis chamber is provided with a mud outlet corresponding to the sludge liquid level height, and the mud outlet is provided with an electric control door. The mud scraping device includes a track extending to the mud outlet, a bucket, a transmission chain, a sprocket, and a motor. The bucket is in sliding fit with the track, and its bucket opening faces one side of the mud outlet. The bucket is fixedly connected to the transmission chain. Sprockets are rotatably arranged at both ends of the track, and the sprockets are engaged with the transmission chain and are rotationally matched with the motor. The motor drives the bucket to periodically scrape the surface layer of the sludge liquid level in the hydrothermal hydrolysis chamber into the mud outlet reciprocally;

[0031] A third conveyor and several steam pipelines are arranged in the mud outlet channel, and the third conveyor is provided with a vibration motor.

[0032] With the above technical solution, the hydrolyzed surface sludge in the heating space is regularly scraped into the sludge discharge channel by a sludge scraper, and a third conveyor is arranged in the sludge discharge channel to convey it to the first mechanical dewatering equipment. A steam pipeline is set to heat the channel to further dry the sludge. The vibration motor is arranged to further set the present invention: splicing flanges and splicing grooves with concave-convex structures are respectively arranged at the splicing end faces of the left half concave die and the right half concave die.

[0033] With the above technical solution, the sealing performance of the combination of the left and right concave dies is increased by the splicing of the concave-convex structure.

[0034] The beneficial effects of the present invention: Through the structural design of the pyrolysis water tank, sludge with a low moisture content is output to the first mechanical dewatering equipment for dehydration. At the bottom of the sludge pyrolysis tank, the wet sludge that cannot be quickly heated due to the depth is directly pumped to the second mechanical dewatering equipment for dehydration, forming sludge with a relatively high moisture content. The nickel hot-pressing forming equipment mixes and burns by proportionally mixing coal powder and wood chips to form a cavity-containing mud shell, and injects wet sludge into the cavity-containing mud shell for hot pressing, maximizing the utilization of a small amount of sludge by hydrolysis and mixing to form a large number of composite sludge blocks. Description of the Drawings

[0035] Figure 1 is the process flow of the embodiment of the present invention Figure 1 ;

[0036] Figure 2 is the structure of the embodiment of the present invention Figure 1 ;

[0037] Figure 3 is the structure of the embodiment of the present invention Figure 2 ;

[0038] Figure 4 is the structure of the embodiment of the present invention Figure 3 ;

[0039] Figure 5 is the structure of the embodiment of the present invention Figure 4 .

[0040] Figure 6 is the structure of the embodiment of the present invention Figure 5 ;

[0041] Figure 7 is the process flow of the embodiment of the present invention Figure 2 .

[0042] Among them, 1 - sludge hydrothermal hydrolysis tank, 11 - partition wall, 12 - hydrothermal hydrolysis chamber, 13 - sludge inlet chamber, 14 - sludge inlet channel, 15 - heating space, 16 - steam pipeline, 17 - sludge outlet channel, 171 - third conveyor, 2 - co-firing mud shell hot pressing and forming equipment, 21 - first input pipe, 22 - second input pipe, 23 - electric rotating table, 231 - support arm, 24 - left half female mold, 25 - right half female mold, 26 - hot pressing male mold, 27 - horizontal track, 28 - horizontal cylinder, 29 - vertical cylinder, 3 - wet and dry sludge perfusion hot pressing and forming equipment, 31 - third input pipe, 32 - first conveyor, 33 - second conveyor, 34 - sealing male mold, 35 - guiding and positioning projection, 341 - end face part, 342 - air column part, 4 - sludge scraping equipment, 41 - bucket, 42 - transmission chain, 43 - track. 5 - mud shell with cavity.

[0043] To better illustrate this embodiment, some components in the drawings are omitted, enlarged or reduced, which do not represent the dimensions of the actual product. In addition, the drawings are only for illustrative purposes and should not be construed as a limitation of this patent. Detailed implementation manners

[0044] To make the technical solutions and their advantages of this application clearer, the technical solutions of this application will be further described clearly and completely in combination with the drawings. It can be understood that the specific embodiments described herein are only partial embodiments of this application, which are only used to explain this application rather than limit this application. It should be noted that for the convenience of description, only the parts related to this application are shown in the drawings, and other related parts can refer to the general design. Without conflict, the embodiments and the technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0045] As Figures 1-7 shown, a municipal sludge drying system includes a sludge hydrothermal hydrolysis tank 1, a first mechanical dewatering device, a second mechanical dewatering device, a co-firing mud shell hot pressing and forming equipment 2, a wet and dry sludge perfusion hot pressing and forming equipment 3 and a sludge feeder; the sludge hydrothermal hydrolysis tank 1 is a semi-underground sealed tank, provided with a partition wall 11, and the partition wall 11 divides the sludge hydrothermal hydrolysis tank 1 into a hydrothermal hydrolysis chamber 12 and a sludge inlet chamber 13, and the sludge inlet chamber 13 is provided with a sludge inlet channel 14;

[0046] The hydrothermal hydrolysis chamber 12 is provided with a heating space 15 above the sludge liquid level, and a steam pipeline 16 communicating with the waste heat boiler system is laid in the heating space 15, and the steam pipeline 16 heats up and controls the temperature of the heating space 15; a sludge scraping equipment 4 is arranged in the heating space 15, and a sludge outlet channel 17 is arranged on one side. The sludge scraping equipment 4 circulates and scrapes the fully hydrothermally hydrolyzed sludge in the heating space 15 to the sludge outlet channel 17 and outputs it to the first mechanical dewatering device for dewatering;

[0047] The bottom layer of the sludge hydrothermal hydrolysis tank 1 is provided with a wet sludge output pipeline, and the wet sludge at the bottom of the tank is pumped to the second mechanical dewatering equipment for dewatering;

[0048] The co-firing mud shell hot pressing and forming equipment 2 includes a pulverized coal and wood chip mixer and a hot pressing die. The hot pressing die mixes and hot presses pulverized coal and wood chips and the sludge dehydrated by the first mechanical dewatering equipment into a cavity-containing mud shell 5;

[0049] The dry and wet sludge pouring and hot pressing and forming equipment 3 injects the sludge dehydrated by the second mechanical dewatering equipment into the cavity-containing mud shell 5 and hot presses it into a co-firing sludge block;

[0050] The sludge feeder inputs the co-firing sludge block into the incinerator.

[0051] In the actual sludge treatment production process, it is impossible to carry out long-term hydrothermal hydrolysis treatment on a large amount of sludge. Therefore, it is designed to carry out hydrothermal heat pressing and dehydration on a small amount of sludge, mix it with pulverized coal and wood chips to form a cavity-containing mud shell 5, improve the combustion performance of the outer shell, and then mechanically dehydrate a large amount of wet sludge and pour it into the cavity-containing mud shell 5 for hot pressing and plasticizing to form a composite sludge block. Due to the low water content of the outer cavity-containing mud shell 5 and the addition of pulverized coal and wood chips to improve the combustion performance of the cavity-containing mud shell 5, the outer cavity-containing mud shell 5 burns fully in the furnace, and the combustion of the cavity-containing mud shell 5 is used to indirectly heat and dry the internal wet sludge. When the outer cavity-containing mud shell 5 burns out, the internal wet sludge has been further dried and the combustion performance has been improved. Under this effect, while improving the drying efficiency of a large batch of sludge, the combustion performance of the sludge is improved. Thus, the problem of increased fuel consumption cost caused by directly inputting wet sludge is avoided.

[0052] Since only a small amount of sludge needs to be subjected to hydrothermal heat pressing and dehydration, while a large amount of sludge is wet sludge dehydration, the overall high-efficiency treatment of sludge is maintained.

[0053] The specific scheme is as follows. The traditional sludge storage is changed to a semi-underground sealed hydrothermal hydrolysis tank. Through the liquid pressure balance between the sludge inlet chamber 13 and the hydrothermal hydrolysis chamber 12 separated by partitions, the sludge liquid level in the hydrothermal hydrolysis chamber 12 is maintained at the same height as the sludge outlet channel 17 by the sludge inlet through the sludge inlet channel 14. The heating space 15 of the hydrothermal hydrolysis chamber 12 is heated and temperature-controlled by the steam pipeline 16 output from the waste heat boiler system, and is maintained between 180 and 210 °C. The sludge scraper runs regularly to scrape the fully hydrothermally hydrolyzed sludge on the liquid surface into the sludge outlet channel 17. Then, the new liquid surface continues the hydrothermal hydrolysis reaction, and so on, and the sludge with low water content is output to the first mechanical dewatering equipment for dewatering.

[0054] At the bottom of the sludge thermal hydrolysis tank 1, the wet sludge that cannot be heated quickly due to its depth is directly pumped to the second mechanical dehydration equipment for dehydration, forming sludge with a higher water content. Through equal-proportional blending and hot pressing, the small amount of thermal hydrolysis sludge is utilized to the maximum extent, and a large amount of composite sludge blocks are formed by blending.

[0055] Mechanical dehydration equipment is conventional equipment, such as flash dryer, rotary drum dryer, etc.

[0056] The mixed-burning mud shell hot pressing forming equipment 2 includes a first input pipe 21, a second input pipe 22, an electric rotating table 23 and a plurality of hot pressing mold mechanisms. The electric rotating table 23 is provided with a plurality of support arms 231 along the radial direction of the rotation. The plurality of hot pressing mold mechanisms are respectively fixedly connected to the plurality of support arms 231. The hot pressing mold mechanisms include a left half die 24, a right half die 25, a hot pressing punch 26, a horizontal track 27, a pair of horizontal cylinders 28 and a vertical cylinder 29. The left half die 24 and the right half die 25 are respectively slidably engaged with the horizontal track 27 and slide together in the horizontal direction to form a complete die with a cavity. The pair of horizontal cylinders 28 are fixedly connected to the horizontal track 27, and their piston rods are respectively connected to the left half die and the right half die 25 to drive the left half die and the right half die 25 to be combined or separated.

[0057] The horizontal track 27 is fixedly connected to a support arm 231, and the support arm 231 is provided with a bracket extending vertically above the complete die;

[0058] The electric rotating table 23 includes a starting position and an ending position. The first input pipe 21 is connected to the first mechanical dehydration device to pump the dehydrated sludge quantitatively into the complete concave mold at the starting position; the second input pipe 22 is connected to the coal powder and sawdust mixer to quantitatively transport the coal powder and sawdust into the complete concave mold at the starting position.

[0059] The vertical cylinder 29 is fixed on the bracket and cooperates with the hot pressing punch 26 to drive the hot pressing punch 26 in and out of the complete die to hot press into a mud shell 5 with a cavity; the hot pressing punch 26, the left half die and the right half die 25 are all provided with heating units.

[0060] The sludge dehydrated by the first mechanical dehydration equipment is quantitatively pumped into the complete concave mold of the starting station, the coal powder and wood chips are quantitatively transported into the complete concave mold of the starting station, and then the hot pressing punch 26 is pressed down to close the mold with the complete concave mold, and the sludge, coal powder and wood chips are mixed and hot-pressed to form a cavity mud shell 5 with a concave cavity.

[0061] The wet and dry sludge perfusion hot pressing and forming equipment 3 includes a third input pipe 31, a first conveyor 32, a second conveyor 33 and a number of sealing and hot pressing mechanisms. The first conveyor 32 is provided with a first conveyor belt, and its head and tail are respectively connected to the complete female mold at the termination station and the second conveyor. The first conveyor belt is located vertically below the complete female mold and is provided with several groups of guiding and positioning convex blocks 35 that are adapted to surround the outer contour of the belt cavity mud shell 5. The left half female mold and the right half female mold are opened horizontally, and the belt cavity mud shell 5 falls into the guiding and positioning convex blocks 35 and is conveyed to the second conveyor 33;

[0062] The second conveyor 33 includes a second conveyor belt arranged vertically above the first conveyor belt and operates at the same synchronous frequency; the number of sealing and hot pressing mechanisms corresponds to the spacing of several groups of guiding and positioning convex blocks 35 and are respectively fixed on the second conveyor belt. The sealing and hot pressing mechanism includes a sealing male mold 34. The sealing male mold 34 includes an end face portion 341 adapted to the inner cavity opening of the belt cavity mud shell 5 and several air column portions 342 inserted into the inner cavity of the belt cavity mud shell 5. The sealing male mold 34 rotates with the second conveyor belt and merges with and separates from the inner cavity opening of the belt cavity mud shell 5;

[0063] The first conveyor belt conveys the sealed belt cavity mud shell 5 to the sludge feeder.

[0064] The left half female mold and the right half female mold 25 are separated left and right along the horizontal track 27, and the belt cavity mud shell 5 naturally falls onto the first conveyor belt and is transported to the lower part of the second conveyor belt. During the transportation process, the higher moisture content sludge dehydrated by the second mechanical dehydration equipment is quantitatively poured into the belt cavity mud shell 5. Along with the synchronous operation of the first and second conveyor belts, the sealing male mold 34 arranged on the second conveyor belt merges with the belt cavity mud shell 5 during operation to heat-seal the higher moisture content sludge in the belt cavity mud shell 5. The end face portion 341 is used to hot-press the inner cavity opening surface of the belt cavity mud shell 5, and the surface of the wet sludge is further dried using heat and solidified in the belt cavity mud shell 5. At the same time, the arranged air column portions 342 form several ventilation holes in the wet sludge, making the solidified sludge block have pores, which can accelerate the drying of the wet sludge inside the belt cavity mud shell 5 during subsequent incineration.

[0065] The hot pressing male mold 26, the left half female mold 24, the right half female mold 25, and the sealing male mold 34 are all made of heat-conducting metal and are provided with electric heating modules inside.

[0066] The hot pressing male mold 26, the left half female mold 24, the right half female mold 25, and the sealing male mold 34 are all made of heat-conducting metal and are provided with heat-conducting oil channels inside. The system also includes a heat-conducting oil heater, which inputs heat-conducting oil into each mold.

[0067] The sludge in the mold is heated and dried through an electric heating module such as an electric heating wire module or a hot oil channel.

[0068] The hydrolysis chamber 12 is provided with a sludge outlet corresponding to the height of the sludge liquid level. The sludge outlet is provided with an electric control door. The sludge scraping device 4 includes a track 43 extending to the sludge outlet, a bucket 41, a transmission chain 42, a sprocket and a motor. The bucket 41 is slidably engaged with the track, and its bucket opening faces the side of the sludge outlet. The bucket 41 is fixedly connected to the transmission chain 42. Sprockets are rotatably arranged at both ends of the track. The sprockets are engaged with the transmission chain and rotationally cooperate with the motor. The motor drives the bucket 41 to periodically scrape the surface layer of the sludge liquid level in the hydrolysis chamber 12 into the sludge outlet reciprocally.

[0069] A third conveyor 171 and a plurality of steam pipelines 16 are arranged in the sludge outlet passage 17. The third conveyor is provided with a vibration motor.

[0070] The surface layer of the hydrolyzed sludge in the heating space 15 is periodically scraped into the sludge outlet passage 17 by a sludge scraper, and a third conveyor 171 is arranged in the sludge outlet passage 17 to convey it to the first mechanical dehydration device. Moreover, steam pipelines 16 are arranged to heat the inside of the passage to further dry the sludge. The vibration motor arranged makes the third conveyor 171

[0071] At the joint end faces of the left half female die and the right half female die 25, a splicing flange and a splicing groove with a concave-convex structure are respectively arranged.

[0072] The sealing performance of the combination of the left and right female dies is increased through the splicing of the concave-convex structure.

[0073] Through the structural design of the pyrolysis water tank, sludge with a low moisture content is output to the first mechanical dehydration device for dehydration. At the bottom of the sludge hydrolysis tank 1, those wet sludges that cannot be quickly heated due to the depth are directly pumped to the second mechanical dehydration device for dehydration, forming sludges with a relatively high moisture content. The nickel hot-pressing forming device mixes and burns coal powder and wood chips in equal proportions to hot-press a cavity-containing mud shell 5, and injects wet sludge into the cavity-containing mud shell 5 for hot-pressing, maximizing the utilization of a small amount of sludge by hydrolysis and mixing to form a large number of composite sludge blocks.

[0074] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the drawings. Those skilled in the art should understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.

Claims

1. A municipal sludge drying system, characterized in that: It includes a sludge thermal hydrolysis tank, a first mechanical dehydration device, a second mechanical dehydration device, a mixed burning mud shell hot pressing molding device, a dry and wet sludge perfusion hot pressing molding device and a sludge feeder; the sludge thermal hydrolysis tank is a semi-underground sealed tank, provided with a partition wall, the partition wall divides the sludge thermal hydrolysis tank into a thermal hydrolysis chamber and a mud inlet chamber, and the mud inlet chamber is provided with a mud inlet channel; The thermal hydrolysis chamber is provided with a heating space above the sludge liquid surface, and the heating space is paved with a steam pipeline connected to the waste heat boiler system, and the steam pipeline heats and controls the temperature of the heating space; a sludge scraping device is provided in the heating space, and a sludge discharge channel is provided on one side, and the sludge scraping device scrapes the sludge that is fully thermally hydrolyzed in the heating space to the sludge discharge channel for output to the first mechanical dehydration device for dehydration; The bottom of the sludge thermal hydrolysis tank is provided with a wet sludge output pipeline, and the wet sludge at the bottom of the tank is pumped to the second mechanical dehydration equipment for dehydration; The hot-pressing molding equipment for the mixed burning mud shell includes a coal powder sawdust mixer and a hot-pressing mold, and the hot-pressing mold mixes the coal powder sawdust and the sludge dehydrated by the first mechanical dehydration equipment and hot-presses them into a mud shell with a cavity; The dry-wet sludge injection and hot-pressing molding equipment injects the sludge dehydrated by the second mechanical dehydration equipment into the mud shell with cavity, and hot-presses it into mixed combustion sludge blocks; The sludge feeder feeds the mixed sludge blocks into the incinerator.

2. The municipal sludge drying system according to claim 1, characterized in that: The hot pressing forming equipment for the mixed fired mud shell comprises a first input pipe, a second input pipe, an electric rotating table and a plurality of hot pressing mold mechanisms, wherein the electric rotating table is provided with a plurality of supporting arms along the radial direction of the rotation, and the plurality of hot pressing mold mechanisms are respectively fixedly connected to the plurality of supporting arms, and the hot pressing mold mechanisms comprise a left half-die, a right half-die, a hot pressing convex die, a horizontal track, a pair of horizontal cylinders and a vertical cylinder, wherein the left half-die and the right half-die are respectively slidably engaged with the horizontal track, and are slidably assembled in the horizontal direction to form a complete die with a cavity, and the pair of horizontal cylinders are fixedly connected to the horizontal track, and the piston rods thereof are respectively connected to the left half-die and the right half-die, and drive the left half-die and the right half-die to be assembled or separated; The horizontal track is fixedly connected to the support arm, and the support arm is provided with a bracket extending to the vertical upper part of the complete die; the electric rotary table includes a starting station and an ending station, the first input pipe is connected to the first mechanical dewatering equipment, and the dehydrated sludge is quantitatively pumped into the complete die at the starting station; the second input pipe is connected to the coal powder and sawdust mixer, and the coal powder and sawdust are quantitatively transported to the complete die at the starting station; the vertical cylinder is fixed on the bracket, and cooperates with the hot pressing punch to drive the hot pressing punch in and out of the complete die, and hot presses it into a mud shell with a cavity.

3. The municipal sludge drying system according to claim 2, characterized in that: The dry and wet sludge perfusion hot pressing molding equipment includes a third input pipe, a first conveyor, a second conveyor and a plurality of sealing hot pressing mechanisms. The first conveyor is provided with a first conveyor belt, and the first and the second conveyors are connected with the complete concave mold of the termination station at the head and the tail, respectively. The first conveyor belt is located vertically below the complete concave mold and is provided with a plurality of groups of guiding and positioning protrusions adapted to the outer contour of the mud shell with cavity. The left half concave mold and the right half concave mold are opened horizontally, and the mud shell with cavity falls into the guiding and positioning protrusions and is transported to the second conveyor. The second conveyor includes a second conveyor belt disposed vertically above the first conveyor belt and operates at the same synchronous frequency; a plurality of sealing and hot pressing mechanisms are respectively fixed on the second conveyor belt corresponding to the spacing of a plurality of groups of guiding and positioning bumps. The sealing and hot pressing mechanism includes a sealing punch. The sealing punch includes an end face adapted to the inner cavity opening of the belt cavity mud shell and a plurality of air column parts inserted into the inner cavity of the belt cavity mud shell. The sealing punch rotates with the second conveyor belt wheel and merges or separates from the inner cavity opening of the belt cavity mud shell; The first conveyor belt conveys the sealed belt cavity mud shell to the sludge feeder.

4. A municipal sludge drying system according to claim 3, characterized in that: The hot pressing punch, the left half die, the right half die, and the sealing punch are all made of heat-conducting metal and are provided with electric heating modules inside.

5. A municipal sludge drying system according to claim 3, characterized in that: The hot pressing punch, the left half die, the right half die, and the sealing punch are all made of heat-conducting metal and are provided with heat-conducting oil channels inside. The system further includes a heat-conducting oil heater, which inputs the heat-conducting oil into each mold.

6. A municipal sludge drying system according to any one of claims 2-5, characterized in that: The hydrothermal hydrolysis chamber is provided with a mud outlet corresponding to the sludge liquid level height. The mud outlet is provided with an electric control door. The mud scraping device includes a track extending to the mud outlet, a bucket, a transmission chain, a sprocket, and a motor. The bucket is slidably matched with the track, and its bucket mouth faces the side of the mud outlet. The bucket is fixedly connected to the transmission chain. Sprockets are rotatably provided at both ends of the track. The sprockets are engaged with the transmission chain and rotationally matched with the motor. The motor drives the bucket to periodically reciprocate and scrape the surface layer of the sludge liquid level in the hydrothermal hydrolysis chamber into the mud outlet; A third conveyor and a plurality of steam pipelines are provided in the mud outlet channel. The third conveyor is provided with a vibration motor.

7. A municipal sludge drying system according to claim 6, characterized in that: The mating end faces of the left half die and the right half die are respectively provided with a splicing flange and a splicing groove with a concave-convex structure.

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