Slag discharge system and slag discharge method

Abstract

This application relates to a slag discharge system, comprising a slag drying device for drying wet slag from an upstream reactor to obtain dry slag, and a slag cooling and conveying device for cooling the dry slag to obtain cooled dry slag. The slag drying device includes a shell, a heating assembly, and a stirring assembly. The shell is provided with a first slag inlet, a first slag outlet, and a gas outlet. The first slag inlet is used to receive wet slag. The heating assembly operates at a temperature between 500-700°C. The stirring assembly includes a stirring power system, a stirring shaft connected to the stirring power system, and a ribbon-type stirring paddle mounted on the stirring shaft. This application also relates to a slag discharge method. The slag discharge system described herein can dry wet slag more quickly, shorten the time spent on waste plastic pyrolysis to produce oil, increase the processing capacity of the waste plastic pyrolysis system, and can rapidly cool high-temperature dry slag, conveying the cooled slag to achieve continuous slag discharge.

Description

Technical Field

[0001] This application relates to the field of waste plastic recycling technology, specifically to a slag discharge system and slag discharge method. Background Technology

[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℃. If the reaction temperature is too high, the oil yield decreases while the gas yield increases, and coking is likely to occur. Currently, pyrolysis reactors typically use molten salt heating. In the later stages of the reaction, some substances in the material are not easily volatilized, and the ash residue is difficult to dry and cannot be quickly discharged from the reactor, occupying internal space and reducing the efficiency of waste plastic feeding. This leads to excessively long waste plastic processing times and difficulty in expanding processing capacity.

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

[0004] Finally, current ash and slag are cooled and conveyed using tubular screw conveyors or tubular chain conveyors. However, tubular screw conveyors are prone to clogging when conveying powdery materials over long distances. Tubular chain conveyors, on the other hand, have disadvantages such as complex structure, high energy consumption when unloaded, high manufacturing cost, poor cooling effect, and difficulty in heat recovery, and are also prone to clogging.

[0005] Therefore, there is an ongoing need in this field to develop a slag removal system and method. Summary of the Invention

[0006] To overcome at least one of the deficiencies in the prior art, the purpose of this application is primarily to provide a slag discharge system capable of rapidly drying and cooling ash slag and recovering the heat energy released during ash slag cooling. Specifically, the slag discharge system described herein includes an ash slag drying device and an ash slag cooling conveying device connected in sequence. The ash slag drying device can dry wet slag from the upstream reactor at an operating temperature of 500-700℃. Furthermore, the ash slag cooling conveying device described herein includes a cooling auger, which comprises a continuous blade auger section and a segmented blade auger section connected in series. The segmented blade auger section has a smaller auger driving force, allowing the ash slag to be refluxed and stirred in this section, thus ensuring sufficient cooling of the ash slag while preventing ash slag blockage.

[0007] The purpose of this application is also to provide a slag removal method that utilizes the slag removal system described above.

[0008] To address the aforementioned technical problems, this application provides the following technical solution.

[0009] In a first aspect, this application provides a slag removal system, the slag removal system comprising:

[0010] The ash drying device is used to dry the wet slag from the upstream reactor to obtain dry slag;

[0011] Ash and slag cooling and conveying device is used to cool dry slag and obtain cooled dry slag;

[0012] The ash drying device includes a shell, a heating component, and a stirring component. The shell is provided with a first ash inlet, a first ash outlet, and an air outlet. The first ash inlet is used to receive wet ash. The heating component operates at a temperature between 500-700℃. The stirring component includes a stirring power system, a stirring shaft connected to the stirring power system, and a ribbon stirring paddle mounted on the stirring shaft.

[0013] In one embodiment of the first aspect, the ash drying device further includes a slag discharge auger assembly, at least a portion of which is disposed within the housing on the side near the first slag discharge port.

[0014] In one embodiment of the first aspect, the lead of the ribbon impeller is between 60% and 100% of the inner diameter of the shell, and the width of the ribbon impeller is between 8% and 15% of the inner diameter of the shell.

[0015] In one embodiment of the first aspect, the ash drying device for the reactor further includes an oil and gas recovery device, and the gas outlet is connected to the oil and gas recovery device.

[0016] In one embodiment of the first aspect, the ash cooling and conveying device includes a second ash inlet, a cooling auger, a U-shaped cooling trough, and a second ash outlet. The second ash inlet and the second ash outlet are respectively connected to the U-shaped cooling trough. The cooling auger is disposed in the U-shaped cooling trough and includes a continuous blade auger section and a segmented blade auger section connected together.

[0017] In one embodiment of the first aspect, the length of the segmented blade auger segment is at least 50% of the length of the cooling auger, preferably 50%-70%.

[0018] In one embodiment of the first aspect, the single-turn blade length of the segmented blade auger section is 30% to 70% of the single-turn blade length of the continuous blade auger section.

[0019] In one embodiment of the first aspect, the ash cooling and conveying device further includes a heat exchange component, the heat exchange component including a heat exchange medium inlet, a heat exchange pipeline and a heat exchange medium outlet connected in sequence, the heat exchange pipeline being in contact with the main shaft of the U-shaped cooling tank and / or the cooling auger.

[0020] In one embodiment of the first aspect, the ash cooling and conveying device further includes a heat recovery device, and the heat exchange medium outlet is connected to the heat recovery device.

[0021] In one embodiment of the first aspect, the slag discharge system further includes an ash collection device for collecting cooled dry slag from the ash cooling conveying device.

[0022] In a second aspect, this application provides a slag removal method, which uses the slag removal system described above.

[0023] Compared with existing technologies, the advantages of this invention lie in the fact that the slag discharge system described herein 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 dry slag to the ash collection device. The ash drying device described herein is separate from the reactor, so its operating temperature can be independently adjusted to between 500-700℃, higher than the reaction temperature of 400-450℃ in the reactor. This allows for faster drying of wet slag, shortens the time required for waste plastic pyrolysis to produce oil, and increases the processing capacity of the waste plastic pyrolysis system.

[0024] In addition, the ash and slag cooling and conveying device described in this article includes a cooling auger, which includes a continuous blade auger section and a segmented blade auger section connected together. The auger driving force of the segmented blade auger section is smaller, which can make the ash and slag reflux and stir in this section. This can ensure that the ash and slag are fully cooled and prevent the ash and slag from clogging. Attached Figure Description

[0025] This application can be better understood by describing the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 This is a schematic diagram of the ash drying device and reaction vessel in one embodiment of this application;

[0027] Figure 2 For example Figure 1 A schematic diagram of the ash drying device in the illustrated embodiment;

[0028] Figure 3 For example Figure 2 A side view of the ash drying device in the illustrated embodiment;

[0029] Figure 4 This is a schematic diagram of the ash cooling and conveying device in one embodiment of this application;

[0030] Figure 5 For example Figure 1 A side view of the ash cooling and conveying device in the embodiment shown;

[0031] Figure 6 This is a schematic diagram of a slag removal system in one embodiment of this application.

[0032] Explanation of icon numbers:

[0033] 100. Reactor; 200. Ash and slag drying device; 210. Shell; 212. First slag inlet; 214. First slag outlet; 216. Gas outlet; 220. Heating assembly; 222. Temperature measuring element; 230. Stirring assembly; 232. Stirring power system; 234. Stirring shaft; 236. Ribbon agitator; 240. Slag discharge auger assembly; 242. Slag discharge power system; 244. Slag discharge auger; 246. Slag discharge valve; 300. Ash and slag 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 plate; 340. Second slag discharge port; 350. Bearing sealing 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 and slag collection device; and 500. Heat recovery device. Detailed Implementation

[0034] Unless otherwise defined, the technical or scientific terms used in this specification and claims shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0035] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] 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 technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] As mentioned above, in existing catalytic cracking processes for waste plastics, plastic oil and ash are obtained by catalytic cracking waste plastics in a pyrolysis reactor. However, in the later stages of the reaction, some substances in the material are not easily volatilized, and the ash is not easy to dry and cannot be quickly discharged from the reactor, occupying the internal space of the reactor. This leads to a decrease in the feeding efficiency of waste plastics, resulting in excessively long processing times and difficulty in expanding processing capacity. In addition, current ash is cooled and transported using tubular screw conveyors or tubular chain conveyors, which are prone to clogging and cannot effectively recover the heat energy released during the cooling of the ash.

[0039] Therefore, in a first aspect, this application provides a slag discharge system capable of rapidly drying and cooling ash slag and recovering the heat energy released during the cooling process. The slag discharge system described herein includes an ash slag drying device and an ash slag cooling conveying device connected in sequence. The ash slag drying device is used to dry wet slag from an upstream reactor, while the ash slag cooling conveying device is used to cool the dried ash slag and convey it to an ash slag collection device. In a preferred embodiment, the slag discharge system described herein may further include a heat recovery device for recovering the heat energy released during the cooling process of the ash slag in the ash slag cooling conveying device.

[0040] In a second aspect, this application provides a slag removal method utilizing the slag removal system described above. In one specific embodiment, the slag removal method includes the following steps: S1: drying wet slag from the upstream reactor in the 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 the ash cooling conveying device, cooling it to the required temperature, and then conveying it to the ash collection device. In one specific embodiment, step S2 further includes recovering the heat energy released during the cooling of the dry slag.

[0041] The technical solution of this application will be clearly and completely described below with reference to the accompanying drawings and embodiments.

[0042] Example 1

[0043] This embodiment involves, for example Figures 1 to 3 The ash drying device 200 shown can be connected to the upstream reactor 100 to receive wet ash from the reactor 100.

[0044] The ash drying device 200 may include a shell 210, a heating assembly 220, and a stirring assembly 230. The heating assembly 220 is located outside the shell 210. At least a portion of the stirring assembly 230 is located inside the shell 210. The shell 210 is provided with a first slag inlet 212, a first slag outlet 214, and a gas outlet 216. The first slag inlet 212 is connected to the slag outlet of the reactor 100. The stirring assembly 230 includes a stirring power system 232, a stirring shaft 234 connected to the stirring power system 232, and a ribbon-type stirring paddle 236 mounted on the stirring shaft 234. The heating assembly 220 may be a cast iron electric heating assembly. Cast iron electric heating assemblies are characterized by high temperature resistance, fast heating speed, and long service life. The ash drying device 200 uses the cast iron electric heating assembly as a heat source, and the operating temperature can reach between 500-700℃.

[0045] The ash drying device 200 can be used in conjunction with the upstream reactor 100. That is, the wet slag requiring high temperatures for drying in the later stages of pyrolysis in the reactor 100 is discharged into the ash drying device 200 for separate high-temperature drying, while the emptied upstream reactor 100 can be refilled with fresh material, thereby improving the working efficiency of the reactor 100. Furthermore, because the material volume is smaller in the later stages of the reaction, the volume of the ash drying device 200 can be correspondingly reduced. This ash drying device 200 has the advantages of easy heating, fast drying speed, and greater energy efficiency and environmental friendliness. Figures 1 to 3 The volume of the ash drying device 200 shown is less than 1 / 3 of that of the reaction vessel 100.

[0046] In some embodiments, the heating assembly 220 is provided with a temperature sensing element 222 and a temperature control system, and the temperature sensing element 222 and the temperature control system are connected. The temperature sensing element 222 may be disposed on the inner wall of the housing 210. By providing the temperature sensing element 222 and the temperature control system, the heating temperature of the heating assembly 220 can be made more precise and controllable.

[0047] In some embodiments, the ash drying apparatus 200 further includes a slag discharge auger assembly 240. The slag discharge auger assembly 240 facilitates the discharge of the dried material from the ash drying apparatus 200. At least a portion of the slag discharge auger assembly 240 is disposed within the housing 210 on the side 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 being disposed within the housing 210, with one end of the slag discharge auger 244 away from the slag discharge power system 242 positioned near the first slag discharge port 214.

[0048] In some embodiments, the ash drying device 200 further includes a slag discharge valve 246 disposed at the first slag discharge port 214. The slag discharge valve 246 can be used to control the discharge of materials. In some embodiments, a check valve is disposed on the air outlet 216. The check valve can be used to control the flow direction of the oil vapor and other volatile gases dried by the ash drying device 200. In some embodiments, the ash drying device 200 for the reactor 100 further includes an oil vapor recovery device, and the air outlet 216 is connected to the oil vapor recovery device.

[0049] In some embodiments, the ash drying apparatus 200 for the reactor 100 further includes a humidity detection element disposed on the inner wall of the housing 210. The humidity detection element may 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.

[0050] Below, in conjunction with Figures 1 to 3 The illustrated embodiment briefly describes the operation of the ash drying device 200 used in the reactor 100.

[0051] First, wet slag from the upstream reactor 100 enters the ash drying device 200 through the first slag inlet 212 located on the shell 210. At this time, the stirring power system 232 drives the ribbon agitator 236 to rotate via the stirring shaft 234. The material is agitated by the ribbon agitator 236, thus achieving material stirring and slag discharge. Simultaneously, the heating component 220 heats the shell 210, thereby raising the temperature of the material. Oil and other volatile gases in the material evaporate upon heating and are discharged from the ash drying device 200 through the air outlet 216 on the shell 210, thus achieving material drying. The dried material is pushed by the ribbon agitator 236 to the vicinity of the first slag discharge port 214. The slag discharge auger assembly 240 assists in discharging the dried material from the first slag discharge port 214 into the downstream ash cooling and conveying device 300.

[0052] In one specific embodiment, the lead of the ribbon agitator 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; if the lead is too large, the propulsion speed is too fast, which is not conducive to agitation. The width of the ribbon agitator 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, which is not conducive to agitation and slag discharge; if it is too wide, the thrust is too large, which is not conducive to ash backflow, causing ash to accumulate at one end and making the equipment unable to operate.

[0053] When the ribbon agitator 236 is in operation, it acts like a scraper, constantly scraping the inner wall of the ash drying device to prevent ash from slagging. Simultaneously, it turns the ash from the inner wall towards the inside of the device, facilitating interface renewal. Because the ribbon agitator 236 has a certain thrust, it can push the ash to the discharge port during ash discharge. When not discharging ash, due to the narrowness and low thrust of the ribbon agitator 236, a large portion of the ash flows back, preventing accumulation and maintaining constant agitation. The ribbon agitator 236 solves both the agitation and ash pushing problems during ash discharge.

[0054] Example 2

[0055] This embodiment relates to a method such as Figures 4 to 6 The ash and slag cooling and conveying device 300 shown is shown.

[0056] The ash cooling and conveying device includes a second ash inlet 310, a cooling auger 320, a U-shaped cooling trough 330, and a second ash outlet 340. The second ash inlet 310 and the second ash 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 ash inlet 310 is provided with a trapezoidal hopper 312 that is narrower at the top and wider at the bottom.

[0057] In such Figure 4 and Figure 5 In the illustrated embodiment, the ash cooling and conveying device may further include bearing sealing assemblies 350 disposed at both ends of the cooling auger 320, which are externally enclosed by cooling water jackets. The bearing sealing assemblies 350 serve to bear and seal the lubricating oil, and the externally enclosed cooling water jackets can cool the bearing sealing assemblies 350. The ash cooling and conveying device may further include a support assembly 360, which allows the ash cooling and conveying device to be arbitrarily installed on the ground or platform. The ash cooling and conveying device may further include a power assembly 370 connected to the cooling auger 320, which includes a geared motor and a power gear connecting the geared motor and the cooling auger 320. The ash cooling and conveying device may further include a U-shaped trough cover plate 332, which can cover the U-shaped cooling trough 330 to prevent leakage of high-temperature dust and high-temperature gas.

[0058] The ash and slag cooling and conveying device further includes a heat exchange assembly 380, which includes a heat exchange medium inlet 382, ​​a heat exchange pipeline 384, and a heat exchange medium outlet 386 connected in sequence. The heat exchange pipeline 384 is in contact with the main shaft of the U-shaped cooling tank 330 and / or the cooling auger 320. The heat exchange assembly 380 can use cooling water as the cooling medium.

[0059] 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 may also be the internal space of a U-shaped cooling tank 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.

[0060] In such Figure 4 and Figure 5 In the illustrated embodiment, the heat exchange assembly 380 includes two cooling pathways. The first pathway is a U-shaped cooling tank water jacket pathway, where cooling water flows into the U-shaped cooling tank water jacket through the heat exchange medium inlet 382 for heat exchange. After absorbing the heat energy of the ash slag within the U-shaped cooling tank water jacket, it flows from the heat exchange medium outlet 386 to the heat energy recovery device. The second pathway is a cooling auger 320 pathway, where cooling water flows into the hollow part of the main shaft of the cooling auger 320 through the heat exchange medium inlet 382 and a rotary joint. The cooling water exchanges heat with the ash slag through the blades and the surface of the main shaft of the cooling auger 320, absorbing heat energy, and then flows from the other end of the rotary joint to the heat energy recovery device 500. By adopting this design, the ash slag cooling and conveying device can effectively achieve ash slag cooling and heat energy recovery.

[0061] In some embodiments, the cooling auger 320 includes a continuous blade auger section 322 and a segmented blade auger section 324 connected to each other. The continuous blade auger section 322 may be located 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 turn of the blades in the segmented blade auger section 324 is 30%-70% of the length of a single turn of the blades in the continuous blade auger section 322. The auger blades of the segmented blade auger section 324 are not continuous, therefore, the auger driving force is relatively small. By employing the segmented blade auger section 324, the ash can be refluxed and stirred in this section, thereby fully cooling the ash.

[0062] In such Figure 4 and Figure 5 In the embodiment shown, 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 turn of the blade in the segmented blade auger section 324 is 50% of the length of a single turn of the blade in the continuous blade auger section 322.

[0063] The segmented blade auger section 324 has a relatively small thrust, serving to agitate and return ash and slag, but its conveying capacity is reduced. A 15%-25% continuous blade auger section 322 is located at the slag inlet end, its main task being to push all the incoming ash and slag into the middle section for agitation and cooling. A 15%-25% continuous blade auger section 322 is also located at the slag outlet end, its main task being to quickly push the ash and slag cooled by the segmented blade auger section 324 to the slag outlet. If the segmented blade auger section 324 is too long, although the cooling effect is good, the driving force is reduced, and it is prone to clogging; if the segmented blade auger section 324 is too short, the ash and slag have a short residence time in the device, resulting in poor cooling effect. Therefore, selecting an appropriate ratio for the segmented agitator is particularly important.

[0064] In such Figure 4 and Figure 5 In the illustrated embodiment, high-temperature ash from the ash drying device 200 enters the ash cooling and conveying device through the second inlet 310. The second inlet 310 is equipped with a trapezoidal hopper 312 that is narrower at the top and wider at the bottom. Due to the shape of the trapezoidal hopper 312, the ash is less likely to bridge within it. Subsequently, the ash is conveyed by a cooling auger 320. When the ash passes through the segmented blade auger section 324, the auger blades are not continuous, resulting in a relatively small auger driving force, causing the ash to be refluxed and stirred in this section, thus fully cooling the ash. The fully cooled ash is then rapidly pushed towards the second outlet 340 by the continuous blade auger section 322 located near the second outlet 340, and discharged from the ash cooling and conveying device 300, entering the ash collection device 400.

[0065] Example 3

[0066] This embodiment involves, for example Figure 6 The slag removal system shown.

[0067] exist Figure 6 In the illustrated embodiment, 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 conveys the cooled dry slag to the ash collection device 400. In a preferred embodiment, the slag discharge system may further include a heat recovery device 500 for recovering the heat released when the high-temperature dry slag is cooled in the ash cooling and conveying device 300.

[0068] The features of the ash drying device 200 and the ash cooling conveying device 300 are as described in Embodiments 1 and 2 above, respectively, and will not be repeated here.

[0069] Example 4

[0070] This embodiment relates to a slag removal method.

[0071] In one specific embodiment, the slag removal method uses the slag removal system described in Example 3. The slag removal method may include the following steps: S1: drying the 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 conveying device 300, cooling it to the required temperature, and then conveying it to the ash collecting device 400. In a preferred embodiment, step S2 further includes recovering the heat energy released during the cooling of the dry slag using a heat recovery device 500.

[0072] The beneficial effects of the slag removal system and method described in this article are that the use of an independent ash drying device 200 to dry the wet slag obtained in the upstream reactor 100 significantly shortens the drying time of the wet slag and increases the overall capacity of the waste plastic recycling system. Furthermore, the use of a segmented cooling auger 300 with anti-clogging properties to cool and transport the high-temperature dry slag from the ash drying device 200 achieves continuous slag removal and increases the safety of the entire waste plastic recycling system.

[0073] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any 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 discharge system for catalytic cracking of waste plastics, characterized in that, The slag removal system includes: The ash drying device is used to dry the wet slag from the upstream reactor to obtain dry slag; Ash and slag cooling and conveying device is used to cool dry slag and obtain cooled dry slag; The ash drying device includes a shell, a heating component, and a stirring component. The shell is provided with a first ash inlet, a first ash outlet, and an air outlet. The first ash inlet is used to receive wet ash. The heating component operates at a temperature between 500-700℃. The stirring component includes a stirring power system, a stirring shaft connected to the stirring power system, and a ribbon stirring paddle mounted on the stirring shaft. The lead of the ribbon impeller is between 60% and 100% of the inner diameter of the shell, and the width of the ribbon impeller is between 8% and 15% of the inner diameter of the shell. The ash cooling and conveying device includes a second ash inlet, a cooling auger, a U-shaped cooling trough, and a second ash outlet. The second ash inlet and the second ash outlet are respectively connected to the U-shaped cooling trough. The cooling auger is disposed in the U-shaped cooling trough and includes a continuous blade auger section and a segmented blade auger section connected together. The length of the segmented blade auger section is 50%-70% of the length of the cooling auger. The ash cooling and conveying device has a continuous blade auger section of 15%-25% at the second slag inlet end and a continuous blade auger section of 15%-25% at the second slag outlet end. The blade auger sections are segmented in between.

2. The slag discharge system as described in claim 1, characterized in that, The ash drying device also includes a slag discharge auger assembly, at least a portion of which is located on the side of the housing near the first slag discharge port.

3. The slag discharge system as described in claim 1, characterized in that, The length of a single turn of the segmented blade auger section is 30%-70% of the length of a single turn of the continuous blade auger section.

4. The slag discharge system as described in claim 1, characterized in that, The ash and slag cooling and conveying device further 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. The heat exchange pipeline is in contact with the main shaft of the U-shaped cooling tank and / or the cooling auger.

5. The slag discharge system as described in claim 4, characterized in that, The ash and slag cooling and conveying device also includes a heat recovery device, and the heat exchange medium outlet is connected to the heat recovery device.

6. The slag discharge system as described in claim 1, characterized in that, The slag discharge system also includes an ash collection device for collecting the cooled dry slag from the ash cooling and conveying device.

7. A method for removing slag, characterized in that, The slag removal method uses the slag removal system as described in any one of claims 1-6, comprising: S1: The wet slag from the upstream reactor is dried in the ash drying device at a temperature of 500-700℃ to obtain dry slag; S2: The dry slag obtained in step S1 is transported to the ash cooling and conveying device, cooled to the required temperature, and then transported to the ash collection device.

8. The slag removal method as described in claim 7, characterized in that, Step S2 also includes recovering the heat energy released during the cooling of the dry residue.

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