Ash cooling and conveying device, ash discharging system, and ash discharging method

Abstract

An ash cooling and conveying device. The ash cooling and conveying device comprises a second ash inlet, a cooling screw conveyor, a U-shaped cooling tank, and a second ash discharging port; the second ash inlet and the second ash discharging port are separately connected to the U-shaped cooling tank; the cooling screw conveyor is arranged in the U-shaped cooling tank; and the cooling screw conveyor comprises a continuous blade screw conveyor section and a segmented blade screw conveyor section which are connected. The present application further relates to an ash discharging system and an ash discharging method. The ash discharging system comprises an ash drying device used for drying wet ash from an upstream reaction kettle to obtain dry ash, and the ash cooling and conveying device used for cooling the dry ash to obtain cooled dry ash. The ash discharging system can dry the wet ash more quickly, thereby shortening the time spent on waste plastic pyrolysis for oil production and improving the treatment capacity of waste plastic pyrolysis systems, and can quickly cool high-temperature dry ash and convey cooled ash to achieve continuous ash discharging.

Description

Ash cooling and conveying device, slag discharge system and slag discharge method Technical Field

[0001] The present application relates to the technical field of waste plastic recycling, and in particular to an ash cooling and conveying device, a slag discharge system, and a slag discharge method. Background Art

[0002] In the production process of catalytic cracking of waste plastics to produce oil, the optimal oil yield and quality are achieved when the reaction temperature is controlled between 400-450°C. If the reaction temperature is too high, the oil yield decreases, the gas yield increases, and coking is more likely to occur. Currently, pyrolysis reactors typically use molten salt heating. In the later stages of the reaction, some substances in the material in these reactors are difficult to volatilize, and the ash residue is difficult to dry and cannot be quickly discharged from the reactor, occupying the reactor's internal space. This reduces the efficiency of waste plastic feeding, resulting in prolonged waste plastic processing time and difficulty in expanding processing capacity.

[0003] In addition, the temperature of the ash obtained after the catalytic cracking reaction of waste plastics is generally between 400-600℃. Currently, reactors all use continuous high-temperature slag discharge. The ash will burn when it comes into contact with air at this temperature, and natural cooling will waste heat energy, which is not conducive to heat energy recovery and storage.

[0004] Finally, current ash and slag are cooled and conveyed using tubular augers or tube chain conveyors. Tubular augers are prone to clogging when conveying powdered materials over long distances. Tubular chain conveyors, on the other hand, have drawbacks such as complex structure, high no-load energy consumption, high manufacturing costs, poor cooling performance, poor heat recovery, and the tendency to clog.

[0005] Therefore, there is a continuous need in the art to develop a slag discharge system and method.

[0006] Summary of the Invention

[0007] In order to overcome at least one of the defects in the above-mentioned prior art, the purpose of this application is first to provide a slag discharge system, which can quickly dry and cool the ash and recover the heat energy released when the ash is cooled. Specifically, the slag discharge system described herein includes an ash drying device and an ash cooling and conveying device connected in sequence. The ash drying device can dry the wet slag from the upstream reactor at an operating temperature of 500-700°C. In addition, the ash cooling and conveying device described herein includes a cooling auger, and the cooling auger includes a connected continuous blade auger section and a segmented blade auger section. The auger driving force of the segmented blade auger section is relatively small, so that the ash can be refluxed and stirred in this section, which can ensure sufficient cooling of the ash and prevent the ash from being blocked.

[0008] The purpose of this application is also to provide a slag discharge method using the slag discharge system as described above.

[0009] In order to solve the above technical problems, this application provides the following technical solutions.

[0010] In the first aspect, the present application provides an ash cooling and conveying device, which includes a second slag inlet, a cooling auger, a U-shaped cooling trough and a second slag discharge port, the second slag inlet and the second slag discharge port are respectively connected to the U-shaped cooling trough, the cooling auger is arranged in the U-shaped cooling trough, and the cooling auger includes a connected continuous blade auger section and a segmented blade auger section.

[0011] In one embodiment of the first aspect, the length of the segmented blade auger section is at least 50% of the length of the cooling auger, preferably 50%-70%.

[0012] In a second aspect, the present application provides a slag discharge system, comprising:

[0013] Ash drying device, used to dry wet slag from upstream reactor to obtain dry slag;

[0014] Ash cooling and conveying device, used to cool dry slag to obtain cooled dry slag;

[0015] Among them, the ash drying device includes a shell, a heating component and a stirring component. The shell is provided with a first slag inlet, a first slag discharge port and an air outlet. The first slag inlet is used to receive wet slag. The working temperature of the heating component is between 500-700°C. The stirring component includes a stirring power system, a stirring shaft connected to the stirring power system and a screw-belt stirring paddle arranged on the stirring shaft.

[0016] In one embodiment of the second aspect, the ash drying device further includes a slag discharge auger assembly, and at least a portion of the slag discharge auger assembly is disposed on a side of the shell close to the first slag discharge port.

[0017] In one embodiment of the second aspect, the lead of the helical ribbon stirring paddle is between 60% and 100% of the inner diameter of the shell, and the width of the helical ribbon stirring paddle is between 8% and 15% of the inner diameter of the shell.

[0018] In one embodiment of the second aspect, the ash drying device for a reactor further includes an oil and gas recovery device, and the gas outlet is connected to the oil and gas recovery device.

[0019] In one embodiment of the second aspect, the ash cooling and conveying device includes a second slag inlet, a cooling auger, a U-shaped cooling trough and a second slag discharge port, the second slag inlet and the second slag discharge port are respectively connected to the U-shaped cooling trough, the cooling auger is arranged in the U-shaped cooling trough, and the cooling auger includes a connected continuous blade auger section and a segmented blade auger section.

[0020] In one embodiment of the second aspect, the length of the segmented blade auger section is at least 50% of the length of the cooling auger, preferably 50%-70%.

[0021] In one embodiment of the second aspect, the length of a single blade turn of the segmented blade auger section is 30% to 70% of the length of a single blade turn of the continuous blade auger section.

[0022] In one embodiment of the second aspect, the ash cooling and conveying device also includes a heat exchange component, which includes a heat exchange medium inlet, a heat exchange pipeline and a heat exchange medium outlet connected in sequence, and the heat exchange pipeline is in contact with the U-shaped cooling trough and / or the main shaft of the cooling auger.

[0023] In an embodiment of the second aspect, the ash cooling and conveying device further includes a heat energy recovery device, and the heat exchange medium outlet is connected to the heat energy recovery device.

[0024] In one embodiment of the second aspect, the slag discharge system further includes an ash collecting device for collecting cooled dry slag from the ash cooling and conveying device.

[0025] In a third aspect, the present application provides a slag discharge method, which uses the slag discharge system described above.

[0026] Compared to the prior art, the present invention has the following positive effects: the slag discharge system includes an ash drying device and an ash cooling and conveying device. The ash drying device is used to dry the wet slag from the upstream reactor into dry slag, while the ash cooling and conveying device is used to cool the dry slag and convey the cooled and dried slag to an ash collection device. The ash drying device described herein is separate from the reactor, so it can independently adjust the operating temperature to between 500-700°C, which is higher than the reaction temperature of 400-450°C in the reactor. This allows for faster drying of the wet slag, shortening the time required to produce oil from waste plastic cracking, and increasing the processing capacity of the waste plastic cracking system.

[0027] In addition, the ash cooling and conveying device described in this article includes a cooling auger, which includes a connected continuous blade auger section and a segmented blade auger section. The auger driving force of the segmented blade auger section is relatively small, so that the ash can be refluxed and stirred in this section, which can not only ensure sufficient cooling of the ash, but also prevent the ash from being blocked. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present application may be better understood by describing the embodiments of the present application in conjunction with the accompanying drawings, in which:

[0029] FIG1 is a schematic structural diagram of an ash drying device and a reactor in one embodiment of the present application;

[0030] FIG2 is a schematic structural diagram of the ash drying device in the embodiment shown in FIG1 ;

[0031] FIG3 is a schematic side view of the ash drying device in the embodiment shown in FIG2 ;

[0032] FIG4 is a schematic structural diagram of an ash cooling and conveying device in one embodiment of the present application;

[0033] FIG5 is a schematic side view of the ash cooling and conveying device in the embodiment shown in FIG1 ;

[0034] FIG6 is a schematic diagram of a slag discharge system in one embodiment of the present application.

[0035] Explanation of the accompanying figures: 100, reactor; 200, ash drying device; 210, shell; 212, first slag inlet; 214, first slag discharge port; 216, air outlet; 220, heating component; 222, temperature measuring element; 230, stirring component; 232, stirring power system; 234, stirring shaft; 236, ribbon stirring paddle; 240, slag discharge auger component; 242, slag discharge power system; 244, slag discharge auger; 246, slag discharge valve; 300, ash cooling and conveying device; 310, second slag inlet 312, trapezoidal bucket; 320, cooling auger; 322, continuous blade auger section; 324, segmented blade auger section; 330, U-shaped cooling trough; 332, U-shaped trough cover; 340, second slag discharge port; 350, bearing seal assembly; 360, support assembly; 370, power assembly; 380, heat exchange assembly; 382, ​​heat exchange medium inlet; 384, heat exchange pipeline; 386, heat exchange medium outlet; 400, ash collection device; and 500, heat energy recovery device. DETAILED DESCRIPTION

[0036] Unless otherwise defined, technical or scientific terms used in this specification and claims shall have the same general meaning as understood by persons having ordinary skills in the technical field to which the present invention belongs.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0038] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," etc., may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0039] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0040] As mentioned above, in existing waste plastic catalytic cracking processes, waste plastic undergoes a catalytic cracking reaction in a pyrolysis reactor to produce plastic oil and ash residue. However, in the later stages of the reaction, some substances in the material are difficult to volatilize, making the ash residue difficult to dry and unable to be quickly discharged from the reactor. This occupies the reactor's internal space, resulting in reduced waste plastic feeding efficiency, prolonged waste plastic processing time, and difficulty in expanding processing capacity. Furthermore, the ash residue is currently cooled and transported using tubular augers or tube chain conveyors, which are prone to clogging and cannot effectively recover the heat energy released during ash cooling.

[0041] To this end, in a first aspect, the present application provides a slag discharge system that can quickly dry and cool ash and recover the heat energy released when the ash is cooled. The slag discharge system described herein includes an ash drying device and an ash cooling and conveying device connected in sequence. The ash drying device can be used to dry wet slag from an upstream reactor, and the ash cooling and conveying device is used to cool the dried ash and convey it to an ash collection device. In a preferred embodiment, the slag discharge system described herein may also include a heat recovery device for recovering the heat energy released when the ash is cooled in the ash cooling and conveying device.

[0042] In a second aspect, the present application provides a slag discharge method utilizing the slag discharge system described above. In one embodiment, the slag discharge method includes the following steps: S1: drying wet slag from an upstream reactor in an ash drying device at a drying temperature of 500-700°C to obtain dry slag; S2: conveying the dry slag obtained in step S1 to an ash cooling and conveying device, cooling it to a desired temperature, and then conveying it to an ash collection device. In one embodiment, step S2 also includes recovering the heat energy released during the cooling of the dry slag.

[0043] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings and embodiments of the present application.

[0044] Example 1

[0045] This embodiment relates to an ash drying device 200 as shown in FIG. 1 to FIG. 3 , which can be communicated with an upstream reactor 100 to receive wet ash from the reactor 100 .

[0046] The ash drying device 200 may include a shell 210, a heating component 220 and a stirring component 230. The heating component 220 is arranged on the outside of the shell 210. At least part of the stirring component 230 is arranged in the shell 210. The shell 210 is provided with a first slag inlet 212, a first slag discharge port 214 and an air outlet 216. The first slag inlet 212 is connected to the slag discharge port of the reactor 100. The stirring component 230 includes a stirring power system 232, a stirring shaft 234 connected to the stirring power system 232, and a spiral belt stirring paddle 236 arranged on the stirring shaft 234. The heating component 220 can be a cast iron electric heating component. The cast iron electric heating component has the characteristics of high temperature resistance, fast heating speed and long service life. The ash drying device 200 uses the cast iron electric heating component as a heat source, and the operating temperature can reach between 500-700°C.

[0047] The ash drying device 200 can be used in conjunction with the upper-stage reactor 100. That is, the wet slag that requires high temperature to dry in the late pyrolysis stage of the reactor 100 is discharged into the ash drying device 200 for separate high-temperature drying, while the empty upper-stage reactor 100 can be recharged with new material, thereby improving the working efficiency of the reactor 100. Moreover, since the volume of the material in the late reaction stage is relatively small, the volume of the ash drying device 200 can also be reduced accordingly. Such an ash drying device 200 has the advantages of easy heating, fast slag drying speed, and greater energy conservation and environmental protection. The volume of the ash drying device 200 shown in Figures 1 to 3 is only less than 1 / 3 of that of the reactor 100.

[0048] In some embodiments, the heating assembly 220 is provided with a temperature measuring element 222 and a temperature control system, and the temperature measuring element 222 and the temperature control system are connected. The temperature measuring element 222 can be provided on the inner wall of the housing 210. By providing the temperature measuring element 222 and the temperature control system, the heating temperature of the heating assembly 220 can be more accurately controlled.

[0049] In some embodiments, the ash drying device 200 further includes a slag discharge auger assembly 240. The slag discharge auger assembly 240 facilitates discharging the dried material from the ash drying device 200. At least a portion of the slag discharge auger assembly 240 is disposed within a side of the housing 210 near the first slag discharge port 214. In some specific embodiments, the slag discharge auger assembly 240 may include a slag discharge power system 242 and a slag discharge auger 244 connected to the slag discharge power system 242. The slag discharge auger 244 is disposed within the housing 210, with the end of the slag discharge auger 244 away from the slag discharge power system 242 disposed near the first slag discharge port 214.

[0050] In some embodiments, the ash drying device 200 further includes a discharge valve 246 disposed at the first discharge port 214. The discharge valve 246 can be used to control the discharge of materials. In some embodiments, the gas outlet 216 is provided with a check valve. The check valve can be used to control the flow of oil, gas, and other volatile gases dried by the ash drying device 200. In some embodiments, the ash drying device 200 used in the reactor 100 further includes an oil and gas recovery device, and the gas outlet 216 is connected to the oil and gas recovery device.

[0051] In some embodiments, the ash drying device 200 for the reactor 100 further includes a humidity detection element disposed on the inner wall of the housing 210. The humidity detection element can be connected to the slag discharge valve 246 and / or the cast iron heating assembly 220. The humidity detection element can help control the drying process.

[0052] Next, the working method of the ash drying device 200 for the reactor 100 will be briefly described with reference to the embodiments shown in FIG. 1 to FIG. 3 .

[0053] First, the wet slag from the upstream reactor 100 enters the ash drying device 200 through the first slag inlet 212 provided in the shell 210. At this time, the stirring power system 232 drives the screw-belt stirring paddle 236 to rotate through the stirring shaft 234, and the material is driven by the screw-belt stirring paddle 236, thereby achieving the stirring of the material and the slag discharge and pushing. At the same time, the heating component 220 heats the shell 210, thereby heating the material, and the oil, gas and other volatile gases in the material are volatilized by the heat and discharged from the ash drying device 200 through the air outlet 216 on the shell 210, thereby achieving the drying of the material. The dried material is pushed to the vicinity of the first slag discharge port 214 by the screw-belt stirring paddle 236, and the slag discharge auger component 240 assists in discharging the dried material from the first slag discharge port 214 out of the ash drying device 200 and into the downstream ash cooling and conveying device 300.

[0054] In a specific embodiment, the lead of the screw-belt stirring paddle 236 is between 60% and 100% of the inner diameter of the ash drying device shell 210. If the lead is too small, the slag discharge speed is slow, and if the lead is too large, the propulsion speed is too fast and is not conducive to stirring; the width of the screw-belt stirring paddle 236 is between 8% and 15% of the inner diameter of the ash drying device shell. If it is too narrow, the thrust is small and is not conducive to stirring and slag discharge; if it is too wide, the thrust is too large and is not conducive to the slag reflux, resulting in ash accumulation at one end, causing the equipment to be unable to operate.

[0055] When the helical ribbon stirring paddle 236 is stirring, it is constantly scraping the inner wall of the ash drying device like a scraper to prevent the ash from coking on the inner wall of the ash drying device. At the same time, it flips the ash on the inner wall of the ash drying device into the ash drying device, which is conducive to the interface renewal of the ash. Because the helical ribbon stirring paddle 236 has a certain thrust, it can push the ash to the slag discharge port during slag discharge. When the slag is not discharged, since the helical ribbon stirring paddle 236 is narrow and has a small thrust, most of the ash will flow back, and there will be no accumulation phenomenon, and it will always remain in a stirring state. The helical ribbon stirring paddle 236 solves both the stirring and the pushing of the ash during slag discharge.

[0056] Example 2

[0057] This embodiment relates to an ash cooling and conveying device 300 as shown in FIG. 4 to FIG. 6 .

[0058] The ash cooling and conveying device includes a second slag inlet 310, a cooling auger 320, a U-shaped cooling trough 330, and a second slag outlet 340. The second slag inlet 310 and the second slag outlet 340 are respectively connected to the U-shaped cooling trough 330, and the cooling auger 320 is disposed within the U-shaped cooling trough 330. In some embodiments, the second slag inlet 310 is provided with a trapezoidal bucket 312 that is narrow at the top and wide at the bottom.

[0059] In the embodiment shown in Figures 1 and 2, the ash cooling and conveying device may further include a bearing seal assembly 150 provided at both ends of the cooling auger 320, the outside of which is surrounded by a cooling water jacket. The bearing seal assembly 150 can carry and seal the lubricating oil, and the cooling water jacket surrounding it can cool the bearing seal assembly 150. The ash cooling and conveying device may further include a support assembly 160, which can arbitrarily install the ash cooling and conveying device on the ground or on a platform. The ash cooling and conveying device may further include a power assembly 370 connected to the cooling auger 320, the power assembly 370 including a reduction motor and a power gear connecting the reduction motor and the cooling auger 320. The ash cooling and conveying device may further include a U-shaped groove cover plate 332, which can be sealed on top of the U-shaped cooling groove 330 to prevent leakage of high-temperature dust and high-temperature gas.

[0060] The ash cooling and conveying device further includes a heat exchange assembly 380, which includes a heat exchange medium inlet 382, ​​a heat exchange pipe 384, and a heat exchange medium outlet 386 connected in sequence. The heat exchange pipe 384 contacts the U-shaped cooling trough 330 and / or the main shaft of the cooling auger 320. The heat exchange assembly 380 can use cooling water as the cooling medium.

[0061] In some embodiments, the main shaft of the cooling auger 320 is a hollow shaft, and the heat exchange pipe 384 is the hollow portion of the hollow shaft. The heat exchange pipe 384 can also be the interior space of a U-shaped cooling trough water jacket. In some embodiments, the ash cooling and conveying device further includes a heat recovery device 500, and the heat exchange medium outlet 386 is connected to the heat recovery device 500.

[0062] In the embodiment shown in Figures 4 and 5, the heat exchange assembly 380 includes two cooling paths. The first path is a U-shaped cooling trough water jacket path. Cooling water flows into the U-shaped cooling trough water jacket through the heat exchange medium inlet 382 for heat exchange. After absorbing the heat energy of the ash in the U-shaped cooling trough water jacket, it flows from the heat exchange medium outlet 386 to the heat energy recovery device. The second path is the cooling auger 320 path. Cooling water flows through the heat exchange medium inlet 382 and into the hollow portion of the main shaft of the cooling auger 320 through a rotary joint. After heat exchange with the ash through the blades and the surface of the main shaft of the cooling auger 320, it absorbs heat energy and flows from the rotary joint at the other end to the heat energy recovery device 500. By adopting this design, the ash cooling and conveying device can effectively achieve ash cooling and heat energy recovery.

[0063] In some embodiments, the cooling auger 320 includes a continuous-blade auger section 322 and a segmented-blade auger section 324. The continuous-blade auger section 322 can be positioned near the second slag outlet 340. In some embodiments, the length of the segmented-blade auger section 324 is at least 50% of the length of the cooling auger 320, preferably 50%-70%. In some embodiments, the length of a single blade turn of the segmented-blade auger section 324 is 30%-70% of the length of a single blade turn of the continuous-blade auger section 322. The auger blades of the segmented-blade auger section 324 are not continuous, and therefore, the auger propulsion force is relatively small. By using the segmented-blade auger section 324, the ash can be refluxed and stirred in this section, thereby fully cooling the ash.

[0064] In the embodiment shown in Figures 4 and 5, the length of the segmented blade auger section 324 is 50% of the length of the cooling auger 320, and the length of a single blade circle of the segmented blade auger section 324 is 50% of the length of a single blade circle of the continuous blade auger section 322.

[0065] The segmented blade auger section 124 has a relatively low thrust, which serves to reflux and stir the ash, but its conveying capacity is reduced. A 15%-25% continuous blade auger section 122 is provided at the slag inlet, whose primary task is to push all incoming ash to the middle section for stirring and cooling. A 15%-25% continuous blade auger section 122 is also provided at the slag discharge outlet, whose primary task is to quickly push the ash cooled by the segmented blade auger section 124 to the slag discharge outlet. Although a segmented blade auger section 124 that is too long has a good cooling effect, it reduces the thrust and is prone to congestion. If a segmented blade auger section 124 is too short, the ash will have a short residence time in the device, resulting in poor cooling. Therefore, selecting the appropriate ratio of segmented agitators is particularly important.

[0066] In the embodiment shown in Figures 4 and 5, the high-temperature ash from the ash drying device 200 enters the ash cooling and conveying device through the second slag inlet 310. The second slag inlet 310 is provided with a trapezoidal bucket 312 that is narrow at the top and wide at the bottom. Due to the shape characteristics of the trapezoidal bucket 312, which is narrow at the top and wide at the bottom, the ash is not easily bridged in the trapezoidal bucket 312. The ash is then conveyed through the cooling auger 320. When the ash passes through the segmented blade auger section 324, because the auger blades of the segmented blade auger section 324 are not continuous, the auger propulsion force is relatively small, causing the ash to reflux and stir in this section, thereby fully cooling the ash. The fully cooled ash is quickly pushed toward the second slag outlet 340 through the continuous blade auger section 122 located near the second slag outlet 340, and is discharged from the ash cooling and conveying device 300 and enters the ash collection device 400.

[0067] Example 3

[0068] This embodiment relates to a slag discharge system as shown in FIG6 .

[0069] In the embodiment shown in Figure 6, the slag discharge system includes an ash drying device 200 and an ash cooling and conveying device 300. The ash drying device 200 is used to dry the wet slag from the upstream reactor 100 to obtain dry slag. The ash cooling and conveying device 300 is used to cool the dry slag from the ash drying device 200 to obtain cooled dry slag, and then convey the cooled dry slag to the ash collection device 400. In a preferred embodiment, the slag discharge system may also include a heat recovery device 500 to recover the heat energy released when the high-temperature dry slag is cooled in the ash cooling and conveying device 300.

[0070] The features of the ash drying device 200 and the ash cooling and conveying device 300 are as described in the above embodiment 1 and embodiment 2 respectively, and will not be repeated here.

[0071] Example 4

[0072] This embodiment relates to a slag removal method.

[0073] In one specific embodiment, the slag discharge method utilizes the slag discharge system described in Example 3. The slag discharge method may include the following steps: S1: drying wet slag from the upstream reactor 100 in the ash drying device 200 at a drying temperature of 500-700°C to obtain dry slag; S2: conveying the dry slag obtained in step S1 to the ash cooling and conveying device 300, cooling it to the desired temperature, and then conveying it to the ash collection device 400. In a preferred embodiment, step S2 also includes utilizing a heat recovery device 500 to recover heat energy released during the cooling of the dry slag.

[0074] The beneficial effect of the slag discharge system and method described herein lies in the use of an independent ash drying device 200 to dry the wet slag obtained in the upstream reactor 100, significantly shortening the drying time of the wet slag and increasing the production capacity of the entire waste plastics recycling system. Furthermore, the use of an ash cooling and conveying device 300 with a segmented cooling auger with anti-clogging properties to cool and convey the high-temperature dry slag from the ash drying device 200 enables continuous slag discharge and increases the safety of the entire waste plastics recycling system.

[0075] The above description of the embodiments is intended to facilitate understanding and application of the present application by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without expending any creative effort. Therefore, the present application is not limited to the embodiments described herein, and improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. A slag cooling and conveying device, characterized in that, The ash slag cooling and conveying device includes a second slag inlet, a cooling auger, a U-shaped cooling tank and a second slag outlet. The second slag inlet and the second slag outlet are respectively connected to the U-shaped cooling tank. The cooling auger is arranged in the U-shaped cooling tank. The cooling auger includes a continuous blade auger section and a segmented blade auger section connected to each other.

2. The slag discharging system according to claim 1, characterized in that, The length of the segmented blade auger section is at least 50% of the length of the cooling auger, preferably 50%-70%.

3. A slag discharging system, characterized in that, The slag discharging system includes: An ash slag drying device for drying the wet slag from the upstream reactor to obtain dry slag; An ash slag cooling and conveying device for cooling the dry slag to obtain the cooled dry slag; Wherein, the ash slag drying device includes a housing, a heating component and a stirring component. The housing is provided with a first slag inlet, a first slag outlet and an air outlet. The first slag inlet is used to receive the wet slag. The operating temperature of the heating component is between 500°C and 700°C. The stirring component includes a stirring power system, a stirring shaft connected to the stirring power system, and a spiral ribbon stirring paddle arranged on the stirring shaft.

4. The slag discharging system according to claim 3, characterized in that, The ash slag drying device further includes a slag discharging auger component, and at least part of the slag discharging auger component is arranged inside the housing on one side close to the first slag outlet.

5. The slag discharging system according to claim 3, characterized in that, The lead of the spiral ribbon stirring paddle is between 60% and 100% of the inner diameter of the housing, and the width of the spiral ribbon stirring paddle is between 8% and 15% of the inner diameter of the housing.

6. The slag discharging system according to any one of claims 3 - 5, characterized in that, The ash slag cooling and conveying device includes a second slag inlet, a cooling auger, a U-shaped cooling tank and a second slag outlet. The second slag inlet and the second slag outlet are respectively connected to the U-shaped cooling tank. The cooling auger is arranged in the U-shaped cooling tank. The cooling auger includes a continuous blade auger section and a segmented blade auger section connected to each other.

7. The slag discharging system according to claim 4, characterized in that, The length of the segmented blade auger section is at least 50% of the length of the cooling auger, preferably 50%-70%.

8. The slag discharging system according to claim 5, characterized in that, The single-turn blade length of the segmented blade auger section is 30%-70% of the single-turn blade length of the continuous blade auger section.

9. The slag discharging system according to claim 5, characterized in that, The ash slag cooling and conveying device further includes a heat exchange component. The heat exchange component includes a heat exchange medium inlet, a heat exchange pipeline and a heat exchange medium outlet connected in sequence. The heat exchange pipeline is in contact with the U-shaped cooling tank and / or the main shaft of the cooling auger.

10. The slag discharging system according to claim 7, characterized in that, The ash slag cooling and conveying device further includes a heat energy recovery device, and the heat exchange medium outlet is connected to the heat energy recovery device.

11. The slag discharging system according to claim 4, characterized in that, The slag discharging system further includes an ash slag collection device for collecting the cooled dry slag from the ash slag cooling and conveying device.

12. A slag discharging method, characterized in that, The slag discharging method uses the slag discharging system according to any one of claims 3-11, and includes: S1: Drying the wet slag from the upstream reactor in the ash slag drying device at a drying temperature of 500°C to 700°C to obtain dry slag; S2: Conveying the dry slag obtained in step S1 to the ash slag cooling and conveying device, cooling it to the required temperature and then conveying it to the ash slag collection device; Preferably, step S2 further includes recovering the heat energy released when cooling the dry slag.

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