WO2005078050A1

WO2005078050A1 - A chemical equipment for thermal cracking waste plastics, rubber, paraffin and heavy oil

Info

Publication number: WO2005078050A1
Application number: PCT/CN2005/000114
Authority: WO
Inventors: Jiwu Hao
Original assignee: Jiwu Hao
Priority date: 2004-02-10
Filing date: 2005-01-27
Publication date: 2005-08-25
Also published as: CN1219851C; CN1557912A

Abstract

The present invention provides an automatically decoking chemical equipment for the thermal cracking of hydrocarbons, such as waste plastics, rubber, paraffin, heavy oil and the mixture of them, which coking easily during hydrocarbon cracking reactions. The cracking reactor, which has metallic filler and screening apparatus, broadens the operation of easy coking hydrocarbons during thermal cracking reactions, the reaction temperature is 200°C~1100°C, reaction pressure less than 0.2Mpa. The equipment of the present invention has high output rate, may be used in continuous industrial production more than 60 days, and its continuous industrial productivity is more than 30ton/d.

Description

Chemical equipment for heating, cracking waste plastic, rubber, paraffin, heavy oil

The invention relates to a chemical equipment for heating and cracking using waste-containing plastics, rubbers, paraffin, heavy oil and mixtures thereof as a main raw material for hydrocarbon-containing materials that are easily coked during the thermal cracking process. Background technique

Traditional industrial external thermal cracking equipment mainly includes thermal storage cracking furnace, sand cracking furnace, molten salt cracking furnace and tube cracking furnace. According to the different heat transfer media, it can be divided into the following three types: ① With a fixed or flowing heat carrier (heat storage brick, sand, molten salt, etc.) as the medium, the heat generated by the combustion of the fuel is transferred to the heat carrier, and then by The heat carrier transfers heat to the reaction raw materials. The cracking furnaces belonging to this heat transfer method include heat storage furnaces, sand furnaces, and molten salt furnaces; ② The metal pipe wall is used as a medium to continuously heat the outer wall of the metal pipe with fuel combustion. Through the heat transfer between the walls, the heat is transferred to the reaction raw material of the tube to be cracked. The cracking furnace belonging to this heat transfer method is a tube-type cracking furnace, etc .; Mixing with the reaction raw materials and transferring heat to the reaction raw materials, cracking furnaces belonging to this heat transfer method include superheated steam cracking furnaces. Among the various types of furnace cracking methods described above, the tube furnace cracking method is the most mature and widely used. Today, 99% of the world's ethylene is produced by a tube furnace cracking process.

I. Thermal storage cracking furnace-The thermal storage cracking furnace is a cracking furnace with a solid thermal carrier as the thermal storage brick. In this cracking furnace, the heat storage bricks act as a heat transfer medium. The heat generated by the combustion of the fuel is stored on the thermal storage bricks and then transferred to the reaction material. Therefore, the regenerative cracking furnace alternates heat storage (heating) and cracking (gas production) in one cycle. Since the characteristic of this cracking method is that the cracking reaction proceeds through heat storage, it is called a thermal storage cracking method. In the cracking and gas making stage, the reaction materials are heated by the heat storage bricks, and the cracking reaction occurs to generate cracked gas containing ethylene, propylene, etc., and at the same time, some coke is formed on the heat storage bricks; while in the heating phase, the fuel will be stored on the one hand when the fuel is burned. The coke formed on the hot brick is burned out. On the one hand, the heat storage brick is heated, and after the purge, it is ready for the next gas generation stage. Therefore, the basic characteristic of the heat storage furnace cracking is that heating and gas production are alternately performed. Intermittent lysis.

The main advantages of thermal storage cracking furnace are as follows:

① The range of raw materials used is wide. Light oil can be used as well as crude oil, heavy oil and even residue as raw materials.

② The cracking furnace has a simple structure and no complicated processing requirements. The thermal storage layer can be made of refractory bricks, Very few steels are used, and no special high-temperature steels are required. It is easy to construct, has a short construction cycle, is fast to launch, and has a small investment. It is suitable for local small and medium-sized petrochemical plants.

Regenerative cracking furnace has the following problems in terms of technical performance:

①Temperature change problem: Because the thermal storage cracking furnace alternates with gas production and heating, the range of temperature change is large, not only changing with time, but also with space.

②Consumption and utilization of heat: Because there are four purges and two pre-blows in a cycle, and the stages are switched alternately, the waste heat is not fully utilized, so the thermal efficiency of the thermal storage cracking furnace is relatively low. This is a serious disadvantage.

③ Low equipment efficiency: As each cycle includes twelve phases, only two of which are gas production phases, and the other ten phases are in non-production state, the equipment efficiency of the thermal storage cracking furnace is low, and the production period Only about 42% of the entire cycle. .

④ Due to the low thermal efficiency of the equipment and the large pollution caused by scorching, thermal storage cracking furnaces are now rarely used.

Second, the sand cracking furnace.

The sand furnace cracking method is a fluidized bed cracking technology developed in the 1960s, which uses sand with a particle size of 0.4 to 1.4 mm as a flowing solid heat carrier. The sand, which has been heated to the hotness, comes into contact with the raw material oil in a fluidized state and sprayed in the reactor to cause a cracking reaction. The difference between this cracking method and the regenerative furnace cracking is that heating, scorching, and gas production are performed in different parts of the equipment, and the sand circulates in these parts and implements an operation at each part, so the cracking process can be Continuously.

The main advantages of the sand cracking furnace are as follows:

① The sand flows in the system, so that the raw hydrocarbon is cracked in the reactor, and the sand is heated and scorched in the riser. Therefore, cracking and heating are not performed in one place, and there is no need to switch alternately. Continuous production can be performed. For example, cracked crude oil flash oil can be used for more than half a year. The production capacity of the sand cracking furnace can be around 30,000 tons of ethylene per year, while the production capacity of most thermal storage cracking furnaces is below 10,000 tons of ethylene per year.

② Because continuous operation is achieved, and the sand particles in the reactor are stirred by the airflow, the heat transfer is good, and the temperature at a certain position in the reactor does not fluctuate greatly with time. Therefore, the olefin recovery rate is higher than that of the thermal storage cracking furnace. Consumption is small. Since the conditions of stable operation, and the reactor is not easily mixed into the flue gas and air, so that the cracked gas containing _{_{C0 2, C0, 0 2,}} N 2 less, preferably cracked gas quality. Due to the continuous operation, heat recovery is also easier than heat storage furnaces.

③ It is convenient to control the reaction conditions and cracking depth, so the ethylene / propylene ratio can be adjusted, and Butadiene and aromatics are by-produced.

④ China's small-scale sand cracking furnace that directly uses crude oil as raw material has been able to run stably, but there are still some problems with the equipment enlargement. Crude flash oil fractions can be used for long-term operation in large and medium sand cracking furnaces. After the crude oil is flashed and the heavy residue is separated, the hydrogen content is increased and the specific gravity is reduced. Since the quality of the flashed oil is improved compared to crude oil, coking can be reduced during the cracking process, and the residue obtained by flash evaporation Oil can be used for steam synthesis to produce raw ammonia for synthetic ammonia, which is a method of comprehensive utilization. After comprehensive utilization, the chemical utilization rate of crude oil can reach more than 60% of crude oil.

The main problems of the sand cracking furnace are as follows:

① There are many equipments, and the investment is larger than the thermal storage furnace cracking method; the equipment structure is more complicated than the thermal storage furnace, the reactor spray gun and internal components are easy to coke and wear, and the operation is more complicated.

② As a heat carrier, the sand flows and is strongly stirred in the equipment. The sand collides with each other and breaks, and at the same time, it rubs against the wall of the device and is worn away. Moreover, the sand undergoes drastic changes in temperature in the equipment: about 600 ~ 700Ό of sand falls from the reactor to the combustion chamber and comes into contact with the flue gas at about 1100 ° C, which suddenly rises in temperature, and about 90CTC of sand falling from the sand storage bucket enter The reactor was suddenly cooled in contact with the raw hydrocarbons and water vapor at about 450 ° C. After repeated repeated heat and cold cycles, the sand may crack and change. For these reasons, a large amount of sand powder and waste sand are generated in the sand cracking system. It is estimated that the abrasion amount of sand in a 1-year-scale sand cracking device of 20,000 to 40,000 tons of ethylene is about 1.6 to 2.3 tons per hour, and new sand and waste sand need to be replenished frequently, resulting in heavy sand transportation. More serious is that a part of the sand powder enters the cyclone separator with the cracking gas, which is caused by sand leakage through the lower sand tube, and the powder flies; the cracked gas entrained with the powder enters the post-processing system, which causes the equipment to be blocked and stops. Because sand is used as a heat carrier, this cracking device can only be built near the area where the sand is produced, which limits the promotion of the sand cracking method to a certain extent.

③ The sand used as a heat carrier needs continuous heating and scorching, and the pollution is large, so the sand cracking furnace is now rarely used.

Third, the tube cracking furnace:

The tube furnace is a set of metal tubes arranged in the furnace. Inside the tube is used to crack raw materials. The outside of the tube is heated by the heat generated by the combustion of liquid fuel or gaseous fuel, and then the heat is transferred through the tube wall to transfer the heat. Give the reaction material in the tube. Due to the high cracking reaction temperature (about 800 ° C), the tube wall temperature must be higher in order to transfer heat into the tube. Therefore, tube furnaces require high-temperature resistant (more than 100Ό) alloy steel pipes. The previous cracking furnaces do not transfer heat through the partition wall, so high temperature resistant alloy steel is not required. In this respect, the requirements of the tubular cracking furnace are higher than other cracking furnaces. But the tube furnace can be operated continuously, which can avoid heat storage. The problems caused by the periodic operation of the furnace; the tubes are fixed during continuous operation of the tube furnace, and it is not necessary to rely on a flowing heat carrier, which can eliminate the problems caused by the sand circulating flow of the sand furnace.

When the cracking reaction occurs in the tube, some secondary reactions will inevitably occur, and coke will be deposited on the inner wall of the tube. Due to continuous production, the coke layer on the inner wall of the tube will become thicker and thicker. After two or three months of operation, it will burn once. And because heavy raw materials with low hydrogen content are more likely to coke during cracking, compared with other cracking furnaces, tube furnaces have certain restrictions on raw materials. Generally, only lighter materials such as light hydrocarbons and naphtha can be used. , Diesel, light diesel, etc., cannot be directly used for hydrocarbon-containing materials that are easily coked during the thermal cracking process.

From the above, it can be seen that the above conventional equipments are not suitable for directly cracking hydrocarbon-containing materials that are easily coked during thermal cracking processes such as waste plastics, rubber, paraffin, and heavy oil.

Waste plastic recycling technology:

With the widespread application of plastics, more and more plastic wastes have seriously polluted the urban and rural environment, and the recycling of waste plastics can not only reduce environmental pollution, but also save a lot of resources. There are three methods for recycling waste plastics: physical processing methods, incineration methods, and cracking oil recovery methods. The physical processing method is to grind waste plastics, remelt them, and process them into fillers and fibers. Typical incineration methods are the waste incinerator method and the coke oven method introduced in 2003, but the incineration method requires a large amount of air to participate in the combustion It is easy to cause atmospheric pollution, and will produce the highly toxic substance Dioxin-DI0XIN, which has been restricted or banned by many European and American countries. The method of cracking and oiling is to heat waste plastic insulation air to a certain temperature for retorting. Similar oil and gas, after further processing, oil products such as gasoline, diesel, kerosene or lubricants can be obtained.

Because the cracking and oil recovery system is completely closed, there is little pollution. At the same time, the cracking and oil recovery method can generate a large number of valuable petrochemical products with a hydrocarbon structure. Using this method to treat plastic waste is more beneficial than incineration or use as fuel.

Special equipment is needed for the cracking, oiling and recycling of waste plastics. The main difficulties to be solved are as follows: ① Due to the poor thermal conductivity of plastics, a long heating time is required before reaching thermal decomposition. When the volume of thermal cracking equipment is constant, the processing capacity per unit time Smaller.

② The coking and carbon deposits generated in the cracking reaction of waste plastic tend to stick to the inner wall of the thermal cracking reactor, which will cause a decrease in thermal efficiency and difficult removal of residual materials.

③ When the waste plastic is heated, many plastics become high-viscosity melts that are difficult to transport and difficult to transport. In the current prior art of waste plastic cracking and oilification recovery methods, the same-purpose reactors are mostly ordinary chemical equipment. During the production process of such equipment, the internal wall and agitator will quickly deposit carbon and coke. As a result, the thermal efficiency of the reactor drops rapidly, and the pipes are blocked, making continuous and efficient production impossible. and so A variety of new plastic and rubber cracking processes that have appeared over the years are all from the perspective of chemical technology. Using existing chemical equipment, the intention is to control the reaction temperature and reaction pressure to suppress heating, cracking equipment, and coking and coking of transmission pipelines. Purpose, but has not achieved significant results. Due to the above disadvantages, most of the existing devices can only handle a single or a few varieties of plastic, and it is generally difficult to achieve continuous large-scale production. Typical thermal cracking equipment such as Ma Zhongjun's method in China, United Carbide Corporation's equipment, Japan Steel's thermal cracking equipment, Mitsubishi Heavy Industries' thermal cracking equipment, Mitsui's thermal cracking process, University of Hamburg lava reactor, University of Hamburg fluidized bed reaction Reactors and other reaction devices have not yet reached a good scale of economic industrialization.

(Note: The above data sources:

1. Chemical Industry Press, Principles and Technology of Petrochemical Cracking, Zou Renjun

2. Liu Junke, "Recycling and Utilization Technology of Plastic Waste", China Petrochemical Press

3. Chemical Industry Press, Domestic Waste Incineration Technology

Typical patented devices with similar functions that can be retrieved are as follows:

1. Name: Reactor for continuous large-scale industrial production. Publication number: CN2425704Y. Patent number: 00236577. 4 Main classification number: B01J19 / 00.

2. Name: Waste plastic refining device capable of continuous industrial production. Publication number: CN2513996Y. Patent number: 01275608. 3 Main classification number: C10B53 / 00.

3. Name: Waste plastic thermal cracking equipment. Publication number: CN1030928A. Application number: 88103988. 8. Main classification number: C10B53 / 00. Applicant: Brownbovilli, Mannheim, Germany. (The patented cracking equipment belongs to sand furnace type)

The purpose of the present invention is to provide a waste plastic, rubber, paraffin, heavy oil and mixtures thereof with a simple structure, capable of automatically removing carbon deposits and coking in the equipment in a continuous production process, and having high thermal efficiency. Hydrocarbon-containing materials that are easily coked during heating and cracking are chemical equipment for heating and cracking as main raw materials.

The disadvantages of the prior art and equipment are that, in the past, this type of cracking reactor structure mainly consisted of a metal container and a stirring device, and the coking inside the container was removed by means of the stirring device. This cracking reactor has the following defects. First, there is an unavoidable gap between the stirring device and the metal container (such as the national standard GB150-1998- 10.2.0.10 for steel pressure vessels). The difference e between the maximum inner diameter and the minimum inner diameter is not more than 1% of the section inner diameter Di, and not more than 25 dishes is qualified. At the same time, considering the thermal deformation of the metal container and the installation error of the stirring device (including a diameter of 1 meter) The average minimum distance between the stirring blades in the above metal container and the inner wall of the container should be more than 10mm). This part of the space will be quickly filled with coke, forming a layer of coke insulation layer, which prevents the smooth conduct of heat conduction and reduces the thermal efficiency. Secondly, the stirring device itself will be gradually covered by coking, and gradually lose the stirring effect, while reducing the effective volume inside the container. Finally, it is generally difficult for the stirring device to pulverize the large coke inside the metal container. Instead, the large coke is rotated together with the stirring device. After long-term use, the internal large piece of coke will gradually increase, further reducing the effective inside the metal container. Volume. Generally, the thermal efficiency of such equipment decreases rapidly, and continuous operation is more difficult. In the heating and cracking chemical equipment of the present invention, a metal filler is added to a metal container, and the metal filler is used to clear the coking inside the metal container. First, the metal filler can achieve close contact with the inner wall of the metal container without improving the manufacturing accuracy of the metal container. The movement of the metal filler relative to the inner wall of the metal container can grind and clear the coke and carbon deposits on the inner wall of the metal container. Secondly, the movement of the metal filler relative to the stirring device can remove the coke on the stirring device. Finally, the metal filler separates and squeezes the material into small pieces, which suppresses the occurrence of large-scale coking. At the same time, the collision of metal fillers with each other will also smash the large-scale coking. Because the thermal conductivity of metal fillers is much higher than that of hydrocarbon-containing materials, the addition of metal fillers enhances the thermal conductivity inside the equipment and improves the thermal efficiency of the device.

The metal container in the heating and cracking chemical equipment of the present invention mainly has two structures; one is a vertical reactor or called a tank type (as shown in FIG. 1), and the other is a horizontal reactor or a cracked tube type. (Figure 2).

The tank reactor has a large volume and is suitable for the preheating stage in the cracking process of hydrocarbon-containing materials. The hydrocarbon-containing materials are initially preheated to 200 ~ 700 ° C. When used in the preheating stage of the waste plastic cracking process, melt the waste plastic and preheat it to 200 ~ 450 ° C. Polyvinyl chloride (PVC) will release most of the chlorine in this temperature range, which facilitates the separate treatment of chlorine. At the same time, the tank reactor can also independently complete the work of heating and cracking the hydrocarbon-containing materials, but the cracking efficiency is lower than that of the cracking tube reactor.

The cracked tube reactor has a large heating area and high thermal efficiency, which can independently complete the heating and cracking of hydrocarbon-containing materials, but it is more effective when used in conjunction with a tank reactor, especially in the heating and cracking reactions of waste plastics and rubber. In the process. The diameter of the cracking tube is 50 ~ 2000 mm. Among them, it is more difficult to install a stirring device in a cracking tube with a diameter of less than 50 mm, and the flow of reactants is small; a cracking tube with a diameter of more than 2000 mm has a smaller heating area and a lower thermal efficiency than a small diameter cracking tube. T / CN2005 / 000114 Difficult to manufacture and install.

The metal filler used in the present invention is repeatedly used in production. The metal filler is made of abrasion-resistant metal or alloy as the outer surface to facilitate heat transfer and increase service life. The typical structure of a metal filler is a solid or hollow metal spherical or ellipsoidal object. This structure is easy to manufacture, has good mobility, and has a small surface area. The coking on the surface is easy to squeeze and clear each other during relative movement, and its smooth appearance can Reduce the adhesion of coke on its surface. Its single largest external dimension is 5 ~ 300 mm, because the metal fillers that are too small (especially less than 5 dishes) require sieve plates with smaller sieve openings than metal fillers to filter. Such sieve openings are easy to plug in use ( Note: The maximum external dimension refers to the distance between two points on the outer surface of the object. Oversized metal fillers have poor mutual mobility and poor focusing. According to the density of the material, the metal filler is made into a structure with different densities of 500 ~ 9000 kg / m3, that is, the metal filler smaller than the material density will float on the upper part of the material inside the reactor, while the density is the opposite. By selecting metal packings of different densities, the metal packings can be more uniformly mixed with the materials inside the reactor, instead of simply sinking to the bottom of the container. When the density and viscosity of the material are large, it is necessary to select a metal filler monomer with a small external size and a high density. In production, one or several metal fillers of different specifications can be selected according to the density and viscosity of the reaction material. If the density of the metal filling is greater than 9000 kg / m3, the energy loss of mechanical stirring will increase, and the wear of the equipment will increase.

The metal filler can be used for surface anti-coking treatment (such as polishing, plating, coating, etc.), or a surface treatment process with a catalyst function for improving cracking efficiency.

When the heating and cracking chemical equipment is composed of a plurality of interconnected containers or cracking tubes, the metal fillers sieved by the screening device in the metal container at the next stage can be lifted to the Material outlet to achieve the purpose of clearing the internal coking of the connecting pipeline of the metal container.

Above the liquid or solid reaction product outlet of the heating and cracking chemical equipment or in the metal filling lifting mechanism, a screening device for separating the reaction material and the metal filling is provided, which can make the solid or liquid material and the metal filling after the reaction react. Separate and enter the next stage of the reactor, while the metal filling remains in the reactor or is lifted to the material inlet of the metal container by a closed mechanical lifting mechanism and re-enters the metal container to continue recycling. Since the heating and cracking chemical equipment of the present invention has a metal filler added, a continuous stirring paddle structure-auger stirring is selected. In a horizontal reactor or a cracking tube cracking reactor, when the total length of the cracking tube is constant, reducing the rotation speed of the spiral stirring can extend the residence time of the reactants in the reactor; on the contrary, it can shorten the reactants in the reaction. Time in the device.

The heating and cracking chemical equipment of the present invention belongs to industrial external heating heating and cracking chemical equipment. Its main principle is close to that of a tubular cracking furnace, except that metal fillers, stirring devices and screening devices are added to improve the anti-coking ability inside the equipment. And thermal conductivity, the raw materials that can be cracked include crude oil, heavy oil, and hydrocarbon-containing materials that are easily coked during thermal cracking, such as waste plastics, rubber, paraffin, and residual oil. The range of raw materials that can be cracked is larger than the existing three The main cracking furnace and the production capacity of a single furnace can reach Γ40,000 tons / year. This device has incomparable advantages in other chemical equipment in terms of waste plastics, rubber cracking and oiling, heating, cracking paraffin, and heavy oil. Its main advantages are as follows:

① The heating and cracking chemical equipment of the invention broadens the range of materials that can be heated and cracked, and can be used for economical industrial heating and cracking of hydrocarbon-containing materials that are easily coked during the heating and cracking process such as waste plastics, rubber, paraffin, and heavy oil. . At the same time, it is especially suitable for cracking reactants with uncertain composition such as waste plastics, rubber, residues and their mixtures.

② The process conditions for heating and cracking have been broadened. Because the equipment has automatic on-line coking ability, it can choose the process section with more coking for reaction, such as increasing the reaction temperature to speed up the reaction speed.

③ It is convenient and quick to adjust the heating and cracking time and temperature. The equipment can adjust the heating and cracking time by adjusting the speed of the stirring device. Temperature adjustment can be achieved by adjusting the temperature of the external heater and burner. This equipment can prolong the cracking time and reduce the reaction temperature when the waste plastic is cracked and oiled, which is beneficial to increase the proportion of oil products in the cracked product.

④ The metal filler can not only remove the coke inside the metal container, but also share and adhere the coke.

⑤ The mixing of the metal filler and the material improves the thermal conductivity of the mixed material in the metal container, thereby improving the overall thermal efficiency of the equipment during production.

⑥ The metal filler separates the cracked reactants into several small pieces in the metal container, which improves the reaction speed and thermal efficiency.

⑦ The reaction materials are reacted in a closed heating and cracking chemical equipment, which is isolated from the air, thereby reducing air pollution. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an assembly diagram of a vertical reactor;

Figure 2 is an assembly drawing of a horizontal reactor;

Figure 3 is a typical structural diagram of a metal filler;

Figure 4 is a detailed view of the vertical reactor screening device of Figure 1;

Figure 5 is an enlarged view of the bottom of the vertical reactor of Figure 1;

Figure 6 is a detailed view of the horizontal reactor screening device of Figure 2;

7 is a partial detail view of the left side of the horizontal reactor of FIG. 2;

Fig. 8 is a partial detail view on the right side of the horizontal reactor of Fig. 2. Drawing number description

In Figure 1: 1. Motor, 2. Transmission, 3. Coupling, 4. Rolling bearing, 5. Frame and flange seal coupling, 6. Packing seal, 7. Gaseous product outlet, 8. Oval head, 9. Flange and its sealing connection parts. 10. Material inlet. 11. Metal filler. 12. Ear support. 13. Stirring shaft. 14. Stirring blades. 15. Cylinder body. 16. 60 degree cone. Head, 17, scraper, 18, sieving device, 19, reaction product outlet, 20, instrument pipe and flange seal coupling, 21, plain bearing, 22, shaft end nut.

In Figure 2: 1. Outlet of reaction product, 2. Screening device, 3. Lead tube of cracking tube, 4. Support tube of cracking tube, 5. Flange cover and its sealing coupling, 6. Sliding bearing, 7. Metal Filler, 8, mixing shaft, 9, propeller blade, 10, material inlet, 11, cracking tube, 12, combustion furnace body, 13, gaseous product outlet, 14, mechanical cabinet, 15, flange and its sealing connection, 16, packing seal, 17, frame, 18, rolling bearing, 19, chain, 20, sprocket, 21, motor, 22, transmission, 23, coupling, 24, rectangular cracking tube, 25, metal filler outlet. detailed description

The device of the present invention is further described below with reference to the drawings.

I. Vertical reactor:

The main container of the vertical reactor (as shown in Figure 1) consists of standard elliptical heads 8, cylinders 15, 60-degree conical heads 16, flanges and their sealing couplings 9, frames and flanges sealed together. Connection piece 5, The instrument takeover and flange seal coupling 20, gaseous product outlet 7, reaction product outlet 19, material inlet 10, and packing seal 6 together form a relatively sealed metal container body. The metal container body is fixed on a steel frame by an ear support 12 welded to the cylinder body 15.

The main body of the mechanical power unit is mounted on the oval head 8 of the container. From top to bottom, it is the motor 1, the transmission 2, the coupling 3, the rolling bearing 4, the frame and flange seal coupling 5, the packing seal 6, and the stirring shaft. 13. Stirring blades 14, most of which are standard chemical machinery and equipment. In order to ensure the stability of the stirring shaft 13, one end of the stirring shaft 13 is fixed on the coupling 3, and the other end is inserted into the sliding bearing 21 in the center of the screening device 18 embedded in the bottom of the metal container. Because the density and viscosity of the mixed material of the reactant and the metal filler 11 are relatively large, a propeller blade structure is used for the stirring blade 14.

The metal filler 11 is generally pre-filled in a metal container before production. The typical structure of the metal filler 11 is a hollow metal sphere, which is made into different densities according to the process characteristics of the reaction material, so as to be evenly mixed with the reaction material, and not only simply sink to the bottom of the reactor, but this structure can also reduce the reaction in the container. The overall density of the mixture of the material and the metal filler 11 improves the stirring efficiency. In order to prevent the metal filler from flowing out of the reactor with the material, a sieving device 18 is installed on the upper part of the material outlet. Its structure is shown in FIG. And the coke block smoothly flows out of the device.

The coking at the outlet can be solved by the following methods: First, the metal fillings of some lower-level metal containers are circulated back to this place; Second, steam is passed at this place to reduce the temperature and suppress the generation of coking; Finally, the A stirring blade is installed at the end to remove coking. These three methods can be used independently or simultaneously, but the latter is more effective.

One function of this equipment is to preheat and liquefy the reaction materials, and initially heat the materials to 200 ~ 70 ° C. The reaction materials such as waste plastics and rubber are preheated and softened. After compression and removal of most of the air, they enter the reactor and metal. The fillers are mixed, mixed with the metal filler under the action of the spiral stirring device, and squeezed and separated into small pieces by the metal filler. The heat transfer medium outside the reactor transmits heat to the outer wall of the metal container and the metal filler. The reactants gradually heat up and liquefy. The liquefied material sinks to the bottom of the reactor under the effect of gravity and enters the next-stage reactor through the reaction product outlet 19. The vaporized oil and gas and cracked gas are from the upper part of the oval head 8. The gaseous product outlet 7 is discharged. The flow control valve at the lower part of the reaction product outlet 19 or the temperature of an external heater can be adjusted to control the preheating temperature of the preheated material. Another function of this equipment is to coke crack various hydrocarbon-containing materials. Second, the horizontal reactor

The main metal container of the horizontal reactor (Figure 2) consists of a plurality of cracking tubes 11, cracking tube conducting tubes 3, flange covers and their sealing couplings 5, the reaction product outlets 1, and the metal filler outlets which are horizontally connected to each other. 25. Material inlet 10, gaseous product outlet 13, flange and its sealing coupling 15, and packing seal 16 together form a relatively sealed metal container body. In order to meet the structural strength requirements, a cracked tube support tube 4 is welded between the cracked tubes. A cracking tube at the bottom of the horizontal reactor is a rectangular cracking tube 24 with rounded corners and a screening device 2 welded in the middle. The main function of the lower spiral of the rectangular cracking tube 24 is to remove the reactant residue.

The mechanical power unit of the horizontal reactor is in order from right to left: motor 21, coupling 23, transmission 22, stirring shaft 8, sprocket 20, chain 19, frame 17, packing seal 16, propeller blade 9, support Bearings (rolling bearings 18, plain bearings 6). Adjacent two shafts are connected by sprocket wheels and chains, and the master-slave transmission relationship ensures that the adjacent two shafts rotate in opposite directions, so that the material flows back and forth in the adjacent two cracking tubes. The stirring shaft 8 is supported by bearings at both ends of the cracking tube. On the other hand, the propeller blade 9 pushes the mixture of the reaction material and the metal filler 7 forward along the cracking tube. The mechanical cabinet 14 is a box made of iron sheet for protecting mechanical parts.

The metal filler 7 is mixed with the material at the material inlet 10 at the upper part of the reactor, and then enters the reactor and is discharged from the metal filler outlet 25 at the end of the bottommost rectangular cracking tube 24. The sieving structure of the metal filler is shown in Figure 6. The solid reaction residue in the material mixture transmitted by the upper propeller blade of the rectangular cracking tube leaks into the lower layer through the screening device 2 and is transported to the reaction product outlet 1 by the lower propeller blade and discharged. The metal container is filled with the metal filler by the upper propeller blade and the metal filler outlet 25 is discharged to the closed lifting device. The closed lifting device lifts the metal filler 7 to the material inlet 10, and the metal filler 7 is mixed with the material at the material inlet 10 at the upper part of the reactor, and then enters the reactor again, so the closed cycle is thus ensured the continuous operation of the production.

The cracked tubular reactor has a large heating area and high thermal efficiency, and its main function is to deep crack the reaction materials. Its cracking temperature is 250 ~ 1200 ° C. The heat emitted by the external burner of the reactor in the combustion furnace body 12 passes through the cracking tube wall and the metal filler 7 and acts on the reactant to cause it to crack and vaporize. The cracked gas is led out of the reactor from the gaseous product outlet 13, and the cracked residue is discharged from the reaction product outlet 1 at the end of the reactor.

When the internal diameter of the cracking tube is 250mm and the spiral speed is 30 rpm, the net liquid reactant flow rate is 3.4 cubic meters / hour; when the internal diameter of the cracking tube is 250mm and the spiral speed is 20 rpm When the net liquid reactant flow rate was 2.2 cubic meters / hour. When the total length of the cracking tube is constant, reducing the rotation speed of the spiral stirring can extend the residence time of the reactants in the reactor. By adjusting the heating temperature and the rotation speed of the spiral stirring at the same time, the cracking reaction speed and the components of the reaction product can be adjusted.

Claims

Claim

1. A chemical equipment for heating and cracking waste plastics, rubber, paraffin, and heavy oil, including metal containers, mechanical power devices, stirring devices, material inlets, liquid or solid reaction product outlets, gaseous product outlets, characterized in that the chemical industry The metal container in the equipment is provided with a metal filler. The metal filler plays a main role in removing coke from the inside of the metal container. The chemical equipment is equipped with a screening device for separating the metal filler from the liquid or solid reaction products.

The chemical equipment according to claim 1, wherein the metal container comprises a single metal container or a plurality of interconnected metal chemical containers.

The chemical equipment according to claim 2, wherein the metal chemical container is a steel chemical container or has a diameter of 50iM! ~ 2000 Legs of Lysis Tube.

The chemical equipment according to claim 1, wherein the metal filler can be repeatedly used in the production process.

The chemical equipment according to claim 1, wherein the metal filler is composed of a plurality of independent metal filler monomers.

The chemical equipment according to claim 5, characterized in that the outer surface of the metal filler monomer is made of metal.

The chemical equipment according to claim 5, wherein the metal filler monomer is solid or hollow, and has a density of 500 to 9000 kg / m3.

The chemical equipment according to claim 5, characterized in that the maximum outer dimension of the metal filler monomer ranges from 5 to 300 legs.

The chemical equipment according to claim 5, characterized in that the metal filler monomers can adopt metal filler monomer structures with different densities and maximum external dimensions according to the characteristics of the processed materials.

The chemical equipment according to claim 1, characterized in that the sieving device prevents the metal filler from passing and allows the liquid or small-diameter solid reaction products to pass.