CN112708429A

CN112708429A - Energy-saving thermal cracking reaction kettle for treating organic solid waste

Info

Publication number: CN112708429A
Application number: CN202011436047.4A
Authority: CN
Inventors: 胡进
Original assignee: Greenlina Switzerland
Current assignee: Greenlina Switzerland
Priority date: 2020-12-10
Filing date: 2020-12-10
Publication date: 2021-04-27

Abstract

The invention discloses an energy-saving thermal cracking reaction kettle for treating organic solid waste, which comprises an outer reaction kettle barrel (14) and an inner reaction kettle barrel (20), wherein at least one group of U-shaped pipe members are arranged on the inner reaction kettle barrel (20), each U-shaped pipe member comprises a U-shaped pipe (25) arranged at the upper part of the inner cavity of the inner reaction kettle barrel (20), two open ends of each U-shaped pipe (25) are respectively connected with the tail end of a flue gas inlet pipe (18) of each U-shaped pipe member and the starting end of a flue gas outlet pipe (26) of each U-shaped pipe member, the opening of the starting end of each flue gas inlet pipe (18) faces to the flowing direction of high-temperature flue gas, and the tail end of the flue gas outlet pipe (26) of each U-shaped pipe member is communicated with a hot air channel smoke. The thermal cracking reaction kettle utilizes part of high-temperature flue gas to directly heat materials in the kettle body through the U-shaped pipe member, so that the heat exchange area is increased, and the energy utilization efficiency is improved.

Description

Energy-saving thermal cracking reaction kettle for treating organic solid waste

Technical Field

The invention belongs to the field of energy and chemical technology, and particularly relates to an energy-saving thermal cracking reaction kettle for treating organic solid waste.

Background

Economic growth and changes in the manner of consumption and manufacture are leading to a rapid increase in the production of plastic waste worldwide. Global plastic production has been increasing for over 50 years. Moreover, since plastic is a non-biodegradable material, it remains in the soil and pollutes the environment.

Currently, only 14% of plastic packages are recycled worldwide [ the above data are derived from: https:// www.theguardian.com/substandable-Business/2017/feb/22/plastics-recycling-fish-chemicals-styrofoam-packaging ], about 800 million tons of plastic being discharged into the ocean each year. They are predated or ingested by marine life and birds, seriously affecting their lives. Some plastics can also be combined with industrial chemicals that have polluted the ocean for decades and raised concerns about possible toxins entering the food chain. According to a recent report by the Allen Macintosh Foundation (Ellen MacArthur Foundation), recycling the remaining 86% of the plastic used for packaging and packaging products at one time can generate revenue of 800-: https:// www.ellenmacarthurfoundation.org/publications/the-new-plastics-environmental-rethinking-the-future-of-plastics ].

Although incineration has been the main waste treatment method so far, the recent increase in the amount and variety of waste has forced policies to shift from simply promoting waste incineration to policies that also promote waste reduction. The amount of waste generated and the amount of waste can be reduced by reusing the waste and recycling it as a resource.

Moreover, the negative environmental impact of emissions from incineration, including atmospheric and soil pollution, is problematic, requiring advanced technologies, particularly to limit the production of dioxins. Currently, 5000 ten thousand tons of common waste (including about 400 thousand tons of waste plastics per year) are produced annually, with about 75% being incinerated. Toxic or harmful emissions associated with incineration are important issues that must be addressed.

The aim of waste-to-energy technology is to treat the potential materials contained in the waste, namely plastics, biomass and rubber tyres, converting them into combustible products, in particular biofuels. As an alternative to incineration technology, thermal cracking technology was developed in the 1970 s, aiming to limit the production of dioxins. Thermal cracking is a simple process, a process that heats organic materials or organics and decomposes them into solids, liquids and gases in an environment with little or no oxygen. The advantage of the thermal cracking process is that it is capable of cracking unsorted and unclean waste plastics/rubbers or other organic solid wastes. In addition, unlike incineration, thermal cracking does not release toxic or harmful emissions to the environment and does not add adverse conditions to further exacerbate an already deteriorating situation over the years.

Comparison of greenhouse gas emissions from thermal cracking processes with other Waste treatment processes [ Sam Haig, et. al Plastic to oil IFM002 final report "Zero Waste Scotland ].]: the emissions associated with the manufacture of other raw materials (excluding waste plastic streams) were 13.0kg CO₂. In the case of thermal cracking, this is due to the hydrogen consumed in the process. The on-site emission of 56kg CO from the incineration of the thermally cracked gas, distillation residue and 3% of the resulting diesel product₂. The emission associated with all transport elements (product and waste) was 197kg CO₂. According to these data, the emission associated with thermal cracking was 266kg CO₂. The emission savings associated with the production of alternative fossil diesel is 426kg CO₂. Overall, the net emission of thermal cracking was-160 kg CO₂。

The waste plastic raw materials mainly come from waste mixtures of plastic products such as Polyethylene (PE), polypropylene (PP), Polystyrene (PS), polyvinyl chloride (PVC) and the like in daily life, such as agricultural films, food packaging bags, engineering waste plastic products or mixed waste plastics selected from domestic garbage landfill sites and the like; the waste rubber raw materials mainly come from waste mixtures of rubber products such as Natural Rubber (NR), Styrene Butadiene Rubber (SBR), Butadiene Rubber (BR) and the like, such as waste tires, rubber soles, rubber part products and the like; under normal conditions, the decomposition temperature of Polyethylene (PE) is about 265 ℃, the decomposition temperature of polypropylene (PP) is about 350-The decomposition temperature is 150 ℃, and the Natural Rubber (NR) is rapidly decomposed at 270 ℃; the butyl Chloride Rubber (CR) is decomposed at 230-260 ℃; waste plastics are a mixture of various plastics such as PE, PP, PS, PVC, etc., waste rubber is a mixture of various rubbers such as NR, SBR, BR, CR., etc., some plastics (such as PE, PVC) or rubbers (such as CR) and the like can be thermally cracked or depolymerized at a lower temperature, and other plastics (such as PP) or rubbers (such as NR) and the like can be effectively and completely thermally decomposed at a higher temperature; other organic solid wastes are derived from municipal domestic wastes, agricultural and forestry wastes, and partial industrial wastes, mainly including paper, kitchen wastes, biomass, industrial sludge and the like. Other organic solid wastes are mainly composed of C, H, O and other elements, and in addition, N, S and other trace elements are also contained; meanwhile, compared with coal, the carbon content of other organic solid wastes is lower, and the H/C and O/C ratios are quite high, so that the organic solid wastes have higher volatile content, but the calorific value is lower than that of common coal, and the characteristics determine that the other organic solid wastes are more suitable for gasification. At the temperature of 200 ℃ below 120 ℃, other organic solid wastes are heated and dried, and the moisture and organic substances are volatilized; at the temperature of 300 ℃ and 500 ℃, most organic substances are completely thermally cracked and volatilized into thermal cracking gas, part of the thermal cracking gas can be condensed into bio-oil, and non-condensable combustible gas mainly comprises CO and H₂、 C₂H₂、 C₂H₄And the like.

In the thermal cracking of organic solid wastes, the conventional way is to heat the outside of the thermal cracking reactor directly or indirectly to reach the required temperature. At present, in various thermal cracking reactors for waste plastics and waste rubber reported in domestic and foreign patents and documents, a method for directly supplying heat to a reaction kettle body by using high-temperature flame is mostly adopted. The main defects are as follows: (1) the local material of the equipment is heated rapidly to raise the temperature due to uneven heating, and the local material at the part which is directly burnt rapidly generates the phenomena of thermal expansion, deformation, oxidation, decarburization and melting of the metal layer and the like, so that the service life of the equipment is greatly reduced; (2) when the oxide layer falls off seriously, the local burning-through of the reaction kettle is easy to cause, high-temperature oil gas in the kettle body leaks, a fire disaster or explosion is caused, and the like, and the reaction kettle is extremely unsafe; (3) direct heat supply is difficult to control the temperature accurately and stably; (4) the flow rate is too fast, so that the heat energy consumption is large and the heat efficiency is low.

The indirect heating of the thermal cracking reactor by burning oil or gas with a burner using a hot-blast stove or a combustion chamber is one of the improved methods for extending the life of the reactor. And the utilization rate of the energy of the thermal cracking reaction kettle is equal to: the energy loss of each of the following portions, subtracted from 100% of the input energy, includes: the energy loss taken away when the smoke generated by combustion is discharged, the heat loss taken away by the evaporation of water, the loss of convection and heat radiation and other various energy losses which are not taken into account.

In the actual production process, the burner needs to continuously supplement oxygen in the use process, and the flue gas generated by combustion needs to be timely discharged by a draught fan, even if a flue gas flow equalizing plate or an airflow baffle plate is arranged on a hot flue gas channel to locally reduce the flow rate of high-temperature and high-speed flue gas [ jiamegapeng, xudang flag, zhang guang, lihongzhi, wear leakage of a low-temperature reheater and analysis and modification of the reason that the temperature of reheated steam is low, thermal power generation, volume 43, second stage, 2014 year 2 month ], but because the hot flue gas channel of a horizontal or vertical thermal cracking reaction kettle is usually very short, a large part of energy provided by combustion is quickly taken away by the flue gas. The practical energy utilization of such thermal cracking heating systems powered by burners is typically only 30-40% of the input energy. Thus in one study thermal cracking was previously described as "high efficiency, low energy consumption", but experimental results indicate that thermal cracking systems have negative efficiency overall, 5-87 times higher energy consumption compared to thermal cracking products [ Rollinson Andrew of Blushful Earth, by weight pyrolysis and 'plastics to fuels' is not a solution to the plastics project, Dec 42018, https:// www.lowimpact.org/pyrolysis-not-solution-plastics-project/].

In the thermal cracking process of the organic solid waste, hot air/flue gas acts on the outside of a thermal cracking reaction kettle, and heat is transferred to the kettle wall through forced convection heat exchange. The heat transfer from the heated tank walls to the organic solid waste within the tank is based primarily on both thermal conduction and thermal radiation. The wall of the kettle body is generally made of metal material, the thickness is not large, the heat conductivity is higher, the metal is 50-415W/m.K, the alloy is 12-120W/m.K [ Peter O.Cervenka, Lou Massa, Applications of dimensional variation to Scaling in the isolated, CARDIVNSWC-TR-95/002 January 1995], otherwise the heat conduction and heat resistance are very small. After the heat enters the interior of the reaction kettle body, the loaded organic solid waste and a small amount of residual air in the kettle body are used as heat carriers, and the heat transfer process of the heat carriers in the reaction kettle mainly depends on heat conduction and heat radiation. Only when the temperature of the heat carrier in the reaction kettle is high, the heat radiation can become the main heat transfer mode. At 23 ℃, the thermal conductivity of HDPE plastic is 0.45-0.52W/m.K, the thermal conductivity of LDPE plastic is 0.33W/m.K, the thermal conductivity of PET plastic is 0.15-0.4W/m.K, the thermal conductivity of PP plastic is 0.1-0.22W/m.K, and the thermal conductivity of PS plastic is 0.1-0.13W/m.K [ data from http:// www.professionalplastics.com (with last access 20.07.2020) ]. Although the thermal conductivity of plastics increases slightly with increasing temperature, it does not change its order of magnitude. The above data indicate that the thermal conductivity of common plastics is very low and the thermal conductivity and resistance are very high. Rubber is also a low thermal conductivity material, a high thermal resistance material, and the thermal conductivity is generally in the range of 0.15-0.4W/m.K [ R.C. Kerschbauer, S. Stieger, M. Gschwandl, T. Hutterer, M. Fasching, B. Lechner, L. Meinhart, J. Hildenbrand, B. Schrittesser, P.F. Fuchs, G.R. Berger, W. Friesenbichle, company of magnetic-state and transient thermal conductivity measuring method using differential industrial rubber group, Polymer Testing 80 (2019) 106121 ]. The thermal conductivity of organic solid waste materials such as wheat straw, oat straw, soybean straw, corn straw, alfalfa hay, and wood shavings is 0.03-0.30W/m.K [ H.K. Ahn, T.J. Sauer, T.L. Richard, T.D. Glanville, Determination of thermal properties of formulating materials, Bioresource Technology 100 (2009) 3971- & lt3 & gt 3973 ], and is also a low thermal conductivity, high thermal resistance material. The thermal conductivity of moist air (assuming a 10% humidity) is approximately 0.035W/m.K [ M. Boukhriss, K. Zhani, R. Ghribi, Study of thermal properties of a solar depletion system using solar energy, depletion and Water Treatment,51(2013)1290-1295, doi: 10.1080/19443994.2012.714925 ]. This means that the residual humid air in the reaction vessel is an excellent insulating material, and has a large thermal resistance.

The total thermal resistance in the heat transfer process is formed by superposing the thermal resistances of all links. The heat transfer coefficient K integrates the characteristics of each link, reflects the overall heat transfer capacity in the heat transfer process and can be expressed as the reciprocal of the total thermal resistance. According to the above data, when heat is transferred from the metallic tank body having high thermal conductivity to the organic solid waste and the residual wet air having internal thermal conductivity different from that of hundreds or even thousands times, since the heat transfer coefficient K of the material side is very low, the "maximum resistance" of the heat transfer process occurs in the reaction tank body, and the heat transfer is effectively prevented from being impaired, so that the temperature increase rate of the material is slow. And because the reaction kettle has large volume and mass, the thermal inertia is large, so that the temperature of the materials in the reaction kettle rises very slowly. Therefore, reducing the thermal resistance of each link can increase the heat transfer coefficient K. According to a general formula Q = KA Delta T for calculating the heat flow in the heat transfer process, three parameters on the right side of the formula are increased for increasing the heat flow Q, wherein K is a heat transfer coefficient, A is a heat transfer area, and Delta T is a temperature difference. By combining the above analysis, the following means are used in the process of directly or indirectly heating and raising the temperature outside the thermal cracking reaction kettle by using the burner: for example, the heat exchange area is increased by arranging heat transfer enhancing fins or fins inside and outside the wall of the reaction kettle body. In the reaction kettle body, because the thermal conductivity of the organic solid waste material in the material side cannot be changed, residual air in the kettle body is reduced, so that the heat transfer coefficient is increased, and the like. However, the above measures can only improve and utilize the part of the energy input by combustion, which is only 30-40% of the energy after deducting the huge heat loss to a certain extent. Most of the energy provided by combustion is taken away by the flue gas which is discharged quickly, and how to more effectively utilize the energy of the flue gas becomes a core problem for increasing the thermal efficiency of the thermal cracking system.

Disclosure of Invention

The invention aims to provide an energy-saving thermal cracking reaction kettle for treating organic solid waste, aiming at the problem that the utilization efficiency of heat energy of a thermal cracking reaction kettle indirectly heated by a combustion engine through a hot blast stove or a combustion chamber in the traditional mode is low.

The invention aims to solve the problems by the following technical scheme:

the utility model provides an energy-saving thermal cracking reation kettle for handling organic solid waste material, includes the outer barrel of reation kettle and the barrel in the reation kettle, its characterized in that: the reaction kettle is characterized in that at least one group of U-shaped pipe members are arranged on the inner barrel of the reaction kettle, each U-shaped pipe member comprises a U-shaped pipe arranged on the upper portion of an inner cavity of the inner barrel of the reaction kettle, two opening ends of each U-shaped pipe are respectively connected with the tail end of a flue gas inlet pipe of each U-shaped pipe member and the starting end of a flue gas outlet pipe of each U-shaped pipe member, the opening of the starting end of each flue gas inlet pipe faces the flowing direction of high-temperature flue gas, and the tail end of each flue gas outlet pipe of each U.

And a fine hole filter screen made of 310S stainless steel and capable of filtering smoke dust is additionally arranged on the inner side of the opening of the starting end of the smoke inlet pipe of the U-shaped pipe member.

The opening of the starting end of the flue gas inlet pipe of the U-shaped pipe member is in an enlarged horn shape, and the tail end of the flue gas inlet pipe of the U-shaped pipe member is connected with the inner barrel of the reaction kettle in a welding or high-temperature resistant sealing manner and is communicated with one opening end of the U-shaped pipe.

The starting end of the smoke outlet pipe of the U-shaped pipe member is connected with the inner cylinder of the reaction kettle in a welding or high-temperature resistant sealing manner and is communicated with the other opening end of the U-shaped pipe.

The flue gas inlet pipe of the U-shaped pipe member, the U-shaped pipe and the flue gas outlet pipe of the U-shaped pipe member are made of seamless stainless steel 310s or 316L, the pipe diameters of the flue gas inlet pipe of the U-shaped pipe member, the U-shaped pipe and the flue gas outlet pipe of the U-shaped pipe member are not less than 80mm, and the wall thicknesses of the flue gas inlet pipe of the U-shaped pipe member, the U-shaped pipe of the U-shaped pipe member.

The flue gas inlet pipe of the U-shaped pipe member and the flue gas outlet pipe of the U-shaped pipe member are both arranged at one end of the barrel body in the reaction kettle, which is close to the high-temperature flue gas source.

The inner wall inboard of the outer barrel of reation kettle has arranged the arc guide plate that sets up along cauldron body axial, and the arc curved surface of arc guide plate is facing the flow direction setting of high temperature flue gas for the arc curved surface of arc guide plate can block high temperature flue gas part and vertically water conservancy diversion to the reation kettle interior barrel that needs the heating.

The arc-shaped guide plates are distributed on the inner wall of the outer barrel of the reaction kettle at equal length and equal distance along the axial direction of the kettle body.

The included angle theta between the tangent line of the bottom end of the arc-shaped curved surface of the arc-shaped guide plate and the axis of the kettle body is 30-40 degrees.

The front end of the arc-shaped guide plate penetrates through the inner side refractory heat-insulating material layer in the composite refractory heat-insulating material and the metal material layer and is fixed on the inner wall of the outer side metal material layer in the composite refractory heat-insulating material and the metal material layer through the shaft support, and the composite refractory heat-insulating material and the metal material layer are positioned on the inner side of the inner wall of the outer barrel of the reaction kettle.

The thickness of the refractory heat-insulating material layer in the composite refractory heat-insulating material and the metal material layer is 25-30mm, and the thickness of the metal material layer is 6-8 mm.

The arc guide plate is made of 316L stainless steel, the length L of the arc guide plate is 300-500 mm, and the distance between the front arc guide plate and the rear arc guide plate along the axial direction of the kettle body is 500-600 mm.

The double-curved-surface-plate fin array reactor is characterized in that double-curved-surface-plate fins arranged in an array mode are arranged on the circumferential outer wall of the inner barrel of the reaction kettle, the double-curved-surface-plate fins are arranged on the circumferential outer wall of the inner barrel of the reaction kettle in an inclined mode of 30-45 degrees, the upper end face, the lower end face, the front side face and the rear side face of any double-curved-surface-plate fin are curved surfaces, the curvatures are kept consistent.

The double-curved-surface plate fins are arranged in a row along the axial direction of the barrel in the reaction kettle, and the double-curved-surface plate fins in any row of double-curved-surface plate fins are all arranged in parallel.

Any one row of the double curved surface plate fins and one row of the double curved surface plate fins on the left side of the double curved surface plate fins are arranged in a positive splayed manner, and the row of the double curved surface plate fins and one row of the double curved surface plate fins on the right side of the double curved surface plate fins are arranged in an inverted splayed manner; on the contrary, any row of the double curved surface plate fins and one row of the double curved surface plate fins on the left side of the double curved surface plate fins are arranged in an inverted splayed shape, and the row of the double curved surface plate fins and one row of the double curved surface plate fins on the right side of the double curved surface plate fins are arranged in a regular splayed shape.

The multiple rows of double curved surface plate fins are uniformly distributed on the circumferential outer wall of the inner cylinder of the reaction kettle, and the curvature of the upper end surface and the lower end surface of each double curved surface plate fin is equal to the curvature of the arc line of the outer surface of the inner cylinder of the reaction kettle, which is attached to the double curved surface plate fin.

The interval of two adjacent hyperboloid plate fins in the same row in the spanwise direction is equal to the curved surface chord length of the hyperboloid plate fins, and the center distance of two hyperboloid plate fins in the adjacent row in the same row is equal to the curved surface chord length of the hyperboloid plate fins.

The height of the double-curved-surface plate fin is 1/15-1/25 of the outer diameter of the cylinder in the reaction kettle, the length of the double-curved-surface plate fin is more than one time of the height of the double-curved-surface plate fin, and the thickness of each double-curved-surface plate fin is 8-10 mm.

The curvature radius of the front side surface and the rear side surface of the hyperboloid plate fin is the circumferential radius of the cylinder in the reaction kettle where the hyperboloid plate fin is located.

The double-curved-surface plate fin is made of 310s or 314 stainless steel and is fixed on the outer surface of the barrel in the reaction kettle in a welding mode.

The reaction kettle is characterized in that a stirring mechanism of a direct-connection transmission single-shaft cutting type is arranged on the inner barrel body, the stirring mechanism comprises a paddle of a spiral cutting type arranged on a stirring paddle main shaft, the two ends of the stirring paddle main shaft extend out of the end part of the inner barrel body of the reaction kettle, and the stirring paddle main shaft is driven by a motor gearbox direct-connection unit.

The main shaft of the stirring paddle is provided with two sections of alternating spiral cutting type blades with equal length, wherein one blade is twisted by 180 degrees clockwise and the other blade is twisted by 180 degrees anticlockwise, the diameter of any blade is 700-900 mm, and the intersection part between the two blades accounts for 15-18% of the length of the single blade.

And the extending end of the main shaft of the stirring paddle is respectively provided with a front bearing seat and a sealing assembly of the stirring mechanism and a rear bearing seat and a sealing assembly of the stirring mechanism.

The extension end of the stirring paddle main shaft is provided with a detachable cooling joint, and a cooling water inlet and a cooling water outlet of the detachable cooling joint are respectively communicated with a water outlet and a water return port of the air-cooled water chiller through pipelines.

The hot air channel exhaust port at the top of the outer barrel of the reaction kettle is communicated with a heat exchanger flue gas inlet of a gas-gas heat exchanger through an exhaust pipeline, a hot air outlet of the gas-gas heat exchanger is communicated with an inlet of an air blower, an outlet of the air blower is communicated with a movable hot air furnace, and high-temperature flue gas output by the movable hot air furnace is sent into a hot air channel between the inner wall of the outer barrel of the reaction kettle and the outer wall of the inner barrel of the reaction kettle.

The air-air heat exchanger is internally provided with pillow-shaped heat transfer plates, cold air input from a cold air inlet of the air-air heat exchanger enters the plate pieces of the pillow-shaped heat transfer plates, and hot air after heat exchange flows out of a hot air outlet and then enters the blower; high-temperature flue gas input from a flue gas inlet of the heat exchanger enters an outer plate channel of the pillow-shaped heat transfer plate, and low-temperature flue gas after heat exchange flows out from a flue gas outlet of the heat exchanger of the gas-gas heat exchanger.

The heat exchanger exhanst gas outlet be connected with centrifugal draught fan's entrance point through centrifugal draught fan inlet duct, centrifugal draught fan's exit end is equipped with centrifugal draught fan air-out pipeline.

Be equipped with the feed gate on the reation kettle feed end of barrel in the reation kettle and atmosphere protective gas entry, be equipped with the oil gas outlet pipe on the reation kettle exit end and overhaul and arrange the slag door, the oil gas outlet pipe with be linked together at high temperature resistant centrifugation draught fan, and the outlet side of high temperature resistant centrifugation draught fan is equipped with centrifugal draught fan air-out port connecting tube.

Compared with the prior art, the invention has the following advantages:

in order to better utilize high-temperature flue gas generated by combustion, the thermal cracking reaction kettle provided by the invention is additionally provided with the U-shaped pipe member on the inner cylinder of the reaction kettle, and partial high-temperature flue gas is utilized to directly heat materials in the inner cylinder of the reaction kettle through the U-shaped pipe member, so that the heat exchange area is increased, and the energy utilization efficiency is improved.

In order to solve the problems of uneven flow field and too high flow speed in the flue gas duct, the thermal cracking reaction kettle is provided with a plurality of arc-shaped guide plates facing the inner cylinder of the reaction kettle on the peripheral side of the hot air duct, and the arc-shaped guide plates can locally block the high-temperature flue gas and longitudinally guide the high-temperature flue gas to the inner cylinder of the reaction kettle to be heated, so that the thermal cracking reaction kettle has the functions of regulating the uniformity of the flow field, reducing the flow speed and regulating the air quantity and temperature of the hot air.

In order to enhance heat transfer of the thermal cracking reaction kettle, the outer surface of the inner cylinder body of the reaction kettle is provided with a hyperboloid plate fin array capable of enhancing heat transfer in a special mode, the hyperboloid plate fins arranged obliquely force fluid to move in a wingspan direction, and the height of the fluid is close to the surfaces of the hyperboloid plate fins, so that the heat transfer is greatly improved.

In order to improve the uniformity of materials, the thermal cracking reaction kettle is characterized in that a direct-connection transmission single-shaft cutting type stirring mechanism is arranged in a barrel in the reaction kettle, a main shaft of a stirring paddle is provided with two sections of alternating spiral cutting type blades with equal length, the stirring mechanism realizes the mixing and dispersion of high-viscosity materials through the combination of shearing, smearing, stretching, folding, compressing, kneading and tearing (mainly materials), and the cutting type stirring paddle has a firm structure and a special design, so that the surfaces of the spiral cutting type blades participating in the mixing are very wide and firm, the high-viscosity and high-load materials can be stably mixed, and the mixing uniformity can reach 99%.

In order to solve the problem that the waste heat of the discharged high-temperature flue gas is not utilized, the thermal cracking reaction kettle recovers the heat taken away by the flue gas discharged from the combustion chamber by arranging the gas-gas heat exchanger and uses the heat to preheat the combustion air of the hot blast stove, the preheating temperature of the combustion air is increased, the stable combustion range of the fuel can be expanded, and the higher the preheating temperature is, the larger the stable combustion range is.

Drawings

FIG. 1 is a schematic view showing the operation state of an energy-saving thermal cracking reactor for treating organic solid wastes according to the present invention;

FIG. 2 is a schematic view of the external and internal structure of the thermal cracking reactor of the present invention;

FIG. 3 is a schematic cross-sectional view of the layout of U-tube components of the present invention on a horizontal thermal cracking reactor;

FIG. 4 is a schematic view of a U-shaped tube structure in the U-shaped tube member of the present invention;

FIG. 5 is a schematic view of an arcuate baffle configuration of the present invention;

FIG. 6 is a schematic diagram of various heat transfer enhancing fins of the prior art, which are distinguished by shape;

FIG. 7 is a schematic structural view of the heat transfer enhanced hyperboloid plate fin of the present invention;

FIG. 8 is a schematic diagram of the arrangement of the heat transfer enhancing hyperboloid plate fin of the present invention on the inner cylinder of the reaction kettle;

FIG. 9 is a schematic cross-sectional view of the arrangement of the enhanced heat transfer hyperboloid plate fin of the present invention on the inner cylinder of a horizontal thermal cracking reactor;

FIG. 10 is a schematic structural view of a direct drive single-axis cutting type stirring mechanism of the present invention;

FIG. 11 is a schematic diagram showing the installation layout and the movement track of stirring blades of a direct-coupled driving single-shaft cutting type stirring mechanism in the inner cylinder of a horizontal thermal cracking reactor;

fig. 12 is a schematic structural view of the gas-gas plate heat exchanger of the present invention.

Wherein: 1-a mobile hot blast stove; 2-oil/gas combustion engine; 3, a blower; 4-hot air outlet of hot-blast stove; 5, a hot air inlet of the reaction kettle; 6-refractory heat-insulating material; 7-hot air inlet support column; 8, a riding wheel bracket and a riding wheel bracket seat; 9-coarse filter screen; 10-feeding end of the reaction kettle; 11-an atmospheric shielding gas inlet; 12-a feed gate; 13-front bearing seat and sealing component of stirring mechanism; 14-outer cylinder of reaction kettle; 15-outer cylinder support frame; 16-composite refractory heat-insulating material and metal material layer; 17-an arc-shaped guide plate; 18-a flue gas inlet tube of a U-shaped tubular member; 19-fine mesh filter screen; 20-inner cylinder of reaction kettle; 21-a hyperboloid plate fin; 22-hot air channel; 23-a blade; 24-stirring paddle main shaft; 25-a U-shaped tube; 26-flue gas outlet pipe of U-shaped tubular member; 27-hot air channel smoke vent; 28-smoke exhaust duct; 29-outlet end of the reaction kettle; 30-oil gas outlet pipe; 31-maintenance and slag discharge door; 32-rear bearing seat and sealing component of stirring mechanism; 33-motor gearbox direct-coupled unit; 34-detachable cooling joint; 35-a support frame body; 36-air-cooled water chiller; 37-cooling water inlet; 38-cooling water outlet; 39-high temperature resistant centrifugal draught fan; 40-centrifugal draught fan support group; 41-connecting a pipeline at an air outlet port of the centrifugal draught fan; 42-gas heat exchanger; 43-fire-resistant insulating layer; 44-pillow shaped heat transfer plates; 45-heat exchanger flue gas inlet; 46-heat exchanger flue gas outlet; 47-cold air inlet; 48-hot air outlet; 49-air inlet pipeline of centrifugal draught fan; 50-centrifugal draught fan; 51-air outlet pipeline of centrifugal draught fan.

Detailed Description

The invention is further described with reference to the following figures and examples.

As shown in fig. 1: in order to better utilize high-temperature flue gas generated by combustion, the energy-saving thermal cracking reaction kettle for treating the organic solid waste is additionally provided with a U-shaped pipe member on the inner cylinder body 20 of the reaction kettle; in order to solve the problems of flow field unevenness and too high flow speed in the flue gas duct, a plurality of arc-shaped guide plates 17 facing the inner cylinder 20 of the reaction kettle are arranged on the outer periphery side of the hot air channel 22; in order to enhance heat transfer, an array of hyperboloid plate fins 21 capable of enhancing heat transfer is arranged on the outer surface of the barrel 20 in the reaction kettle in a special way; in order to improve the uniformity of materials, a direct-connection transmission single-shaft cutting type stirring mechanism is arranged in the inner cylinder body 20 of the reaction kettle; a gas-gas heat exchanger 42 for preheating combustion air in the movable hot blast stove 1 by using the waste heat of the flue gas outside the reaction kettle; the details are as follows.

One, U-shaped pipe member

In order to better utilize the high-temperature flue gas generated by combustion, in the invention, as shown in fig. 2, 3 and 4, a U-shaped pipe member is adopted to directly heat the materials in the reaction kettle body by utilizing part of the high-temperature flue gas, so that not only is the heat exchange area increased, but also the energy utilization efficiency is improved. The U-shaped pipe member is composed of a flue gas inlet pipe 18 of the U-shaped pipe member, a fine mesh screen 19, a U-shaped pipe 25, and a flue gas outlet pipe 26 of the U-shaped pipe member. The U-shaped pipe member is made of seamless stainless steel 310s or 316L, and the wall thickness of the U-shaped pipe member is consistent with the thickness of the barrel body 20 in the reaction kettle. The initial section of the U-shaped pipe member is a flue gas inlet pipe 18 of the U-shaped pipe member, which in practical application is used as an inlet pipe of the U-shaped pipe member for receiving high-temperature flue gas, and is placed outside the inner cylinder 20 of the reaction kettle and inside the hot air channel 22 between the outer cylinders 14 of the reaction kettle. The intermediate main portion of the U-shaped tube member is a U-shaped tube 25 as shown in figures 3 and 4. The U-shaped pipe 25 is arranged above the paddle 23 of the single-shaft stirring mechanism in the inner cylinder 20 of the reaction kettle and is parallel to the central axis of the horizontal thermal cracking reaction kettle. The length of the U-shaped pipe 25 is less than the length of the inner cavity of the barrel 20 in the reaction kettle. The outlet section of the U-shaped pipe member is a flue gas outlet pipe 26 of the U-shaped pipe member, the flue gas outlet pipe 26 of the U-shaped pipe member and the flue gas inlet pipe 18 of the U-shaped pipe member are distributed on the left side and the right side of the feeding end 10 of the reaction kettle, and the axial leads of the two pipelines are parallel to each other and are positioned on the left side of the inner barrel body 20 of the reaction kettle.

As shown in figure 1 and figure 2, in order to utilize high-temperature flue gas, a detachable 310S stainless steel coarse-hole filter screen 9 is arranged at the tail part of a hot air inlet 5 of a reaction kettle of the horizontal thermal cracking reaction kettle. The opening of the starting end of the flue gas inlet pipe 18 of the U-shaped pipe member is in an enlarged trumpet shape and is used as an inlet of high-temperature flue gas; in order to prevent dust carried by the smoke from blocking a pipeline of the U-shaped pipe member, the diameter of the seamless stainless steel pipe adopted in the invention is larger, the pipe diameter is more than or equal to 80mm, and a fine hole filter screen 19 made of 310S stainless steel for filtering smoke dust is additionally arranged at the smoke inlet end (starting end) of the smoke inlet pipe 18 of the U-shaped pipe member; the tail end of the flue gas inlet pipe 18 of the U-shaped pipe member is connected with the inner cylinder 20 of the reaction kettle in a welding or high temperature resistant sealing way and is communicated with one open end of the U-shaped pipe 25. The starting end of the flue gas outlet pipe 26 of the U-shaped pipe member is connected with the inner cylinder 20 of the reaction kettle in a welding or high temperature resistant sealing manner and is communicated with the other opening end of the U-shaped pipe 25, and the tail end of the flue gas outlet pipe 26 of the U-shaped pipe member is communicated with the hot air channel smoke exhaust port 27 through a bypass. The three hot air channel exhaust ports 27 shown in fig. 1 not only allow the removal of flue gases from the hot air channels 22, but also from the U-shaped tubular members.

The flow direction of the high-temperature flue gas in the hot air channel 22 of the pyrolysis reactor and in the U-shaped pipe member is shown by the marked flue gas flow direction arrows in fig. 1 and 2 under the synergistic action of the blower 3 and the centrifugal induced draft fan 50 in fig. 1. A part of the flue gas in the hot air channel 22 is filtered by the fine-hole filter screen 19 and then is sucked by the flue gas inlet pipe 18 of the U-shaped pipe member; because the U-shaped pipe member is seamless and is in sealed connection with the barrel 20 in the reaction kettle and independently conveys hot fluid, the sucked flue gas can only flow and transfer heat along the U-shaped pipe member, and the high-temperature flue gas transfers heat to the materials in the barrel 20 in the reaction kettle, passes through the flue gas outlet pipe 26 of the U-shaped pipe member and the hot air channel exhaust port 27 and is finally pumped and discharged into the exhaust pipeline 28. The U-shaped member of the present invention can be used not only in a horizontal thermal cracking reactor but also in a vertical thermal cracking reactor or the like.

Second, guide plate

In order to solve the problem of non-uniform flow field in the flue gas duct, a guide plate is usually arranged in the flue gas main duct.

In the invention, a plurality of arc-shaped guide plates 17 which are equal in length and are distributed at equal intervals are arranged in the hot air channel 22 on the inner side of the inner wall of the outer cylinder 14 of the reaction kettle along the axial direction of the kettle, and the arc-shaped curved surfaces of the arc-shaped guide plates 17 are parallel to each other. The arc-shaped guide plate 17 is used for locally blocking hot air by the arc-shaped curved surface and longitudinally guiding the hot air to the inner cylinder 20 of the reaction kettle to be heated, so that the effect of adjusting the air volume and the temperature of the hot air is achieved. As shown in fig. 5, the included angle θ between the tangent line of the bottom end of the arc curved surface of the arc guide plate 17 and the axis of the kettle body is 30-40 °, the length L of the arc guide plate 17 is 300-500 mm, and the size of the arc guide plate can be revised according to the actual working condition. In order to effectively prevent high-temperature corrosion and ensure the safe and reliable flow guiding, the arc-shaped flow guide plate 17 is made of 316L stainless steel. The front end of each arc-shaped guide plate 17 penetrates through the composite refractory heat-insulating material of the outer barrel 14 of the reaction kettle and the refractory heat-insulating material layer with the thickness of 25-30mm in the metal material layer 16 and is fixed on the inner wall of the composite refractory heat-insulating material and the metal material layer 16 through a shaft support, and the metal material layer is 6-8mm thick. The distance between the front and the rear arc-shaped guide plates 17 is 500-600 mm. According to the computer CFD simulation experiment data, the arc-shaped guide plate 17 can not only guide the flow of gas, so that the gas flow tends to be stable, but also can reduce a high-speed area and a low-speed area, so that the speed uniformity is greatly improved, and the pressure loss of the system can be reduced. When theta is 30-40 degrees, the heat exchange efficiency can be increased by more than 10 percent.

Third, strengthen the heat transfer fin

The function of the fins is to enhance heat transfer. The heat transfer amount is proportional to the heat transfer area, the heat transfer coefficient and the temperature difference. Q = KA Δ T, where Q is the heat transfer amount, K is the heat transfer coefficient, a is the heat transfer area, and Δ T is the temperature difference. To enhance heat transfer, it is necessary to increase the heat transfer area, enhance the heat transfer coefficient, or increase the temperature difference. Since the operating temperature is usually limited, increasing the temperature difference is not always feasible in practice. The more common method is to increase the heat transfer coefficient or increase the heat transfer area. Methods of enhancing heat transfer coefficients include the use of forced convection, the use of two-phase flow; the method for enlarging the heat transfer area is to use fins, and the fins can enhance heat transfer and can also be used for heat dissipation. In the air flow, heat transfer at the fin surface is achieved by three main mechanisms, natural convection, forced convection, and radiant heat transfer.

Various different shapes of fins are used in industrial production as shown in fig. 6: plate fins such as flat plate fins, triangular fins, parabolic fins, cylindrical fins such as cylinders, square columns, hexagonal columns and cones, annular fins such as circular rings and -type fins; in addition, there are fixed cross-section fins and variable cross-section fins, which are distinguished by cross-sectional area. Rectangular fins are often used in practice to increase the rate of convective heat transfer, since they are both simple and easy to manufacture.

As shown in fig. 1 and fig. 2, eight groups of arrays of hyperboloid plate fins 21 with an inclination angle of 45 ° are arranged on the outer surface of the inner cylinder 20 of the horizontal thermal cracking reactor to enhance heat conduction, and the structure of the hyperboloid plate fins 21 is shown in fig. 7. One pair of the array of the hyperboloid plate fins 21 is shown in fig. 8, wherein the height of each hyperboloid plate fin 21 is about 1/15-1/25 of the outer diameter of the cylinder 20 in the reaction kettle, and the length of each hyperboloid plate fin is twice of the height. The thickness of each hyperboloid plate fin 21 is 8-10 mm, the span-wise interval (equal to the interval between the same ends of the two hyperboloid plate fins 21, but not the shortest distance between the two hyperboloid plate fins) between two adjacent hyperboloid plate fins 21 in the same column is equal to the curved surface chord length of the hyperboloid plate fin 21, and the center distance between two hyperboloid plate fins 21 in the adjacent column and the same row is equal to the curved surface chord length of the hyperboloid plate fin 21. The hyperboloid plate fin 21 is made of 310s or 314 stainless steel and is fixed on the outer surface of the barrel body 20 in the reaction kettle in a welding mode. The curvature of the upper end surface and the lower end surface of each hyperboloid plate fin 21 is equal to the curvature of an arc line of the outer surface of the inner cylinder 20 of the reaction kettle, which is attached to the hyperboloid plate fin, and the arc line can be regarded as a certain arc on an elliptic section intersecting line with a section plane and the axis of the cylindrical kettle forming an inclination angle of 45 degrees; the curvature radius of the front and back side surfaces of the double-curved-surface plate fin 21 is the circumferential radius of the barrel 20 in the reaction kettle.

The cross-sectional view of the arrangement of the fin array on the outer surface of the inner cylinder 20 of the horizontal thermal cracking reactor is shown in fig. 9, and fig. 9 shows that the hyperboloid plate fins 21 with the inclination angle of 45 degrees are arranged on each circular arc with the interval of 45 degrees on the circumference of 360 degrees of the cross section of the inner cylinder 20 of the horizontal thermal cracking reactor.

After the hyperboloid plate fin 21 inclined at an angle of 45 degrees is arranged, the fluid is forced to move along the span direction, and the height of the fluid is close to the surface of the hyperboloid plate fin 21, so that the heat transfer is greatly improved; heat transfer increases in laminar flow of about 40-50% and turbulent flow of about 15-20%, but pressure drop is insignificant and less than 1 Pa; when the reynolds number is high, the heat conduction of the model with the fin inclination angle θ of 45 ° is slightly higher than that of the model with the inclination angle θ of 30 °, and the arrangement of the hyperboloid plate fins 21 can greatly change the temperature distribution of the heat transfer sheet.

Four, directly ally oneself with rabbling mechanism of transmission unipolar cutting type

The physical and mechanical properties of the plastic are closely related to the temperature, and the stress behavior of the plastic changes when the temperature changes, so that different physical states are presented. With the temperature rise of the thermal cracking reaction kettle, the waste plastic or rubber presents three mechanical states of glass state, high elastic state and viscous state on the macroscopic performance, and two changes from the glass state to the high elastic state and from the high elastic state to the viscous state.

Generally, the viscosity of low molecular liquid is small, and the viscosity is basically not changed along with the flowing state after the temperature is determined, such as room temperature,the viscosity of water is about 1 mpa.s. The absolute value of the viscosity of non-Newtonian liquid such as high molecular plastic or rubber is generally high when the non-Newtonian liquid is converted into liquid by heating. Zero shear viscosity eta of polymer melt_０Are all at 10²～10⁴In the range of Pa.s, 10 of the viscosity of water⁶The melt viscosity was found to be high. Fluids with a viscosity of less than 5pa.s are generally considered low viscosity fluids; the fluid of 5-50Pa.s is medium viscosity fluid; 50-500Pa.s of a high viscosity fluid. For very high viscosity fluids above 500pa.s, such as plastic or rubber melts as described herein.

In the thermal cracking process of waste plastics or rubber and other materials, when the temperature in the thermal cracking reaction kettle exceeds the viscous flow temperature T of the materials_fIf the thermal cracking reaction kettle is not uniformly stirred and the heat transfer between the kettle wall of the thermal cracking reaction kettle and the material is not uniform, abnormal operation phenomena such as sticking of the material to the kettle, agglomeration and even bed death are easily caused, and the normal operation of the thermal cracking reaction kettle is influenced. The slag formation on the inner wall of the kettle body after the thermal cracking reaction frequently encountered in the thermal cracking production industry is caused by the reason that the materials become extremely high-viscosity fluid and then flow smoothly and are heated unevenly. If the kettle body is not cleaned, the slagging on the inner wall of the kettle body becomes thicker and thicker, and the heat conduction is seriously influenced. When the plastic or the rubber is in a viscous state, the viscosity is 1000-10000 Pa.s. In order to solve the above-mentioned problem of adhesion, the present invention introduces a direct-drive single-shaft cutting type stirring mechanism shown in fig. 10 into the body of the thermal cracking reactor. The cutting type stirring paddle is the most tough stirring paddle, and the mixing and dispersion of high-viscosity materials are realized by the combination of shearing, smearing, stretching, folding, compressing, kneading and tearing (mainly materials). Due to the strong structure and special design of the cutting type stirring paddle, the surface of the spiral cutting type stirring paddle 23 participating in mixing is very wide and strong, so that high-viscosity and high-load materials can be stably mixed, and the mixing uniformity can reach as high as 99%.

The direct-drive single-shaft cutting type stirring mechanism shown in fig. 10 is mainly composed of the following components: the device comprises a spiral cutting type blade 23, a stirring paddle main shaft 24, a front bearing seat and sealing assembly 13 of a stirring mechanism, a rear bearing seat and sealing assembly 32 of the stirring mechanism, a motor gearbox direct connection unit 33, a detachable cooling joint 34 and the like.

As shown in fig. 10: the stirring mechanism of the invention adopts a single-shaft layout, and the main shaft 24 of the stirring paddle is provided with two sections of alternating spiral cutting type blades 23 with equal length. One of the blades 23 is twisted 180 ° clockwise and the other blade 23 is twisted 180 ° counter-clockwise. The diameter of the paddle 23 is 700-900 mm, and the arrangement can provide sufficient radial and axial mixing; and the intersection between two paddles 23 accounts for 15-18% of the length of a single paddle 23. Because the operation temperature in the barrel 20 in the reaction kettle is higher, the paddle 23 is made of high-temperature-resistant stainless steel. In addition, in order to prevent the bearings of the main shaft 24 of the stirring paddle from overheating, the front end and the rear end of the stirring mechanism are respectively provided with a detachable cooling joint 34, the front end and the rear end of the stirring mechanism can be connected with a set of air-cooled water cooler 36 for preventing the bearings from overheating, the air-cooled water cooler 36 is connected with the detachable cooling joints 34 through pipelines, and the bearings are cooled through the circulation of cooling water between a cooling water inlet 37 and a cooling water outlet 38.

The installation layout of the direct-drive single-shaft cutting type stirring mechanism in the thermal cracking reaction kettle is shown in figures 1 and 2. Because the material (waste plastic or waste rubber) filled in the inner cylinder 20 of the reaction kettle is heated to a certain temperature, the solid → liquid transition occurs, and thus, the volume change is very significant, so that a large space appears above the inner cavity of the inner cylinder 20 of the reaction kettle which is almost filled initially, and the liquid level line at this time may be slightly higher than the central axis of the inner cylinder 20 of the reaction kettle or below the central axis. If the main shaft 24 of the stirring paddle of the stirring mechanism is arranged along the central axis of the barrel 20 in the reaction kettle, after the material is heated to be liquid, the paddle 23 can not contact the material in the circumferential motion, so that the stirring is not uniform, and the efficiency is low. In order to sufficiently stir the molten liquid, a paddle shaft 24 is disposed below the central axis of the barrel 20 in the reaction vessel, as shown in fig. 11. The motion track of the stirring blade 23 in the inner cylinder 20 of the reaction kettle is shown by a dotted line in fig. 11, the maximum circumferential motion range of the blade 23 should be as close to the inner wall kettle bottom of the inner cylinder 20 of the reaction kettle as possible, and such a layout can enable the materials to be sufficiently stirred in both solid and liquid states; the clearance between the outermost edge of blade 23 of stirring and the inner wall bottom of barrel 20 in the reation kettle is 8 ~ 10 mm.

Five, gas-gas heat exchanger

In order to solve the problem that the waste heat of the discharged high-temperature flue gas is not utilized, the heat taken away by the flue gas discharged from the combustion chamber is recovered and used for heating combustion air. The preheating temperature of the combustion air is increased, so that the stable combustion range of the fuel can be expanded; the higher the preheating temperature, the larger the stable combustion range.

The gas-gas heat exchanger is applied to working conditions of gas heating (preheating), cooling (precooling), waste heat recovery and the like. Under the working condition of gas-gas heat exchange, the traditional heat exchanger has low heat transfer efficiency, too large pressure loss and incapability of being effectively used or almost incapable of coping with dust. The gas-gas heat exchanger 42 employed in the present invention is used for heat exchange between flue gas and air, and is designed based on a laser welding pillow plate heat transfer technology. The pillow-shaped heat transfer plate 44 shown in fig. 12 is processed by full-automatic laser welding and post-forming process, and its special pillow-shaped structure makes the fluid in and between the pillow-shaped heat transfer plate 44 form the best turbulent state, so as to achieve efficient heat transfer. A plurality of pillow-shaped heat transfer plates 44 are arranged in the gas-gas heat exchanger 42 at certain intervals; the interior of the plate is a clean gas channel, cold air enters the interior of the plate of the pillow-shaped heat transfer plate 44 from a cold air inlet 47, and hot air after heat exchange flows out from a hot air outlet 48, enters the blower 3 and is sent into the movable hot blast stove 1. The outside of the pillow-shaped heat transfer plate 44 is a high-temperature flue gas channel, and high-temperature flue gas enters the gas-gas heat exchanger 42 from the smoke exhaust pipeline 28 through a heat exchanger flue gas inlet 45; the low-temperature flue gas after heat exchange flows out from the flue gas outlet 46 of the heat exchanger, enters the air inlet pipeline 49 of the centrifugal induced draft fan, and is discharged through the air outlet pipeline 51 of the centrifugal induced draft fan under the action of the centrifugal induced draft fan 50. The distance between the pillow-shaped heat transfer plates 44 can be flexibly designed and adjusted according to the use condition. The gas-gas heat exchanger 42 has the technical characteristics of extremely high heat exchange coefficient, small pressure drop, high temperature and high pressure resistance, dust resistance, easy cleaning and the like which are obviously superior to those of the traditional heat exchanger.

Example one

In the present invention, as shown in FIG. 1, the inner barrel 20 of the horizontal thermal cracking reactor is placed inside the outer barrel 14 of the reactor. The feed end 10 and the outlet end 29 of the reaction vessel are partially located in the outer cylinder 14 of the reaction vessel and partially located outside the outer cylinder 14 of the reaction vessel. In the figure 1, the weights of a reaction kettle feed end 10, a reaction kettle inner cylinder 20, a reaction kettle outlet end 29, waste raw materials filled in the kettle, a stirring mechanism of the reaction kettle and a U-shaped pipe member are supported by four groups of supporting roller supports and supporting roller support seats 8, a plurality of hot air inlet supporting columns 7 and supporting frame bodies 35; the weight of the outer cylinder 14 of the reaction kettle is supported by a plurality of outer cylinder supporting frames 15; the hot air channel 22 is a space between the inner wall of the outer barrel 14 of the reaction kettle and the outer wall of the inner barrel 20 of the reaction kettle; and a composite fireproof heat-insulating material and a metal material layer 16 are filled between the outer barrel 14 of the reaction kettle and the hot air channel 22.

Before the organic solid waste is filled, a high-temperature resistant centrifugal induced draft fan 39 is started to pump out air in the barrel 20 in the reaction kettle; firstly, pre-treating 2000 kg of waste plastic/rubber by rough crushing, metal recovery, mechanical dehydration, drying, crushing, and the like, then compacting into small blocks, then feeding the small blocks into a barrel body 20 in a reaction kettle through a feeding door 12 by an external feeder, starting a direct-connection transmission single-shaft cutting type stirring mechanism to mix and feed materials in the feeding process, and closing the feeding door 12 after filling; then, nitrogen or CO2 protective gas is injected into the inner cylinder body 20 of the reaction kettle through the atmosphere protective gas inlet 11, so that the whole thermal cracking reaction is in an oxygen-free or low-oxygen condition, and then the atmosphere protective gas inlet 11 is closed; firstly, pre-treating 2000 kg of waste plastic/rubber by rough crushing, metal recovery, mechanical dehydration, drying, crushing, and the like, then compacting into small blocks, then feeding the small blocks into a barrel body 20 in a reaction kettle through a feeding door 12 by an external feeder, starting a direct-connection transmission single-shaft cutting type stirring mechanism to mix and feed materials in the feeding process, and closing the feeding door 12 after filling; moving a movable hot blast stove 1 to a horizontal thermal cracking reaction kettle, hermetically connecting a hot blast stove hot blast outlet 4 of the movable hot blast stove 1 with a hot blast inlet 5 of the reaction kettle, arranging a refractory heat-insulating material 6, starting ignition of an oil/gas burner 2, and making hot blast enter a hot blast channel 22 from the hot blast inlet 5 of the reaction kettle after passing through a 310S stainless steel coarse-hole filter screen 9 under the action of a blower 3; the high-temperature flue gas flowing in the hot air channel 22 can heat the whole barrel 20 in the reaction kettle, so that the condition of uneven heat distribution can be reduced. Along the axial direction of the kettle body, a plurality of arc-shaped guide plates 17 are arranged on the upper edge and the lower edge of an air channel of the hot air channel 22, the arc-shaped surfaces of the arc-shaped guide plates 17 partially block hot air and longitudinally guide the hot air to the inner barrel 20 of the reaction kettle to be heated, and therefore the effect of adjusting the hot air quantity and the temperature is achieved. In order to enhance heat conduction, eight groups of hyperboloid plate fin arrays 21 with the inclination angle of 45 degrees are arranged on the outer surface of the cylinder 20 in the reaction kettle. Under the synergistic action of the blower 3 and the centrifugal induced draft fan 50 shown in fig. 1, as shown in fig. 2, a part of high-temperature flue gas in the hot air channel 22 is filtered by the 310S stainless steel fine-hole filter screen 19 and then is sucked by the flue gas inlet pipe 18 of the U-shaped pipe member; because the U-shaped pipe member is seamless, the U-shaped pipe member is in sealed connection with the barrel 20 in the reaction kettle and independently conveys hot fluid, the sucked flue gas can only flow along the inner cavity of the U-shaped pipe member and transfer heat, the flue gas can directly heat materials in the barrel 20 in the reaction kettle, and the materials are finally pumped and discharged into the smoke discharge pipeline 28 after being transferred heat through the flue gas outlet pipe 26 of the U-shaped pipe member and the smoke discharge port 27 of the hot air channel. In addition, the high temperature flue gas collected by the other two hot air channel exhaust ports 27 is also discharged into the exhaust flue 28. The high-temperature flue gas enters the gas-gas heat exchanger 42 through the smoke exhaust pipeline 28 and the heat exchanger flue gas inlet 45; the low-temperature flue gas after heat exchange of the gas-gas heat exchanger 42 flows out of the heat exchanger flue gas outlet 46 and enters the air inlet pipeline 49 of the centrifugal draught fan, under the action of the centrifugal draught fan 50, the low-temperature flue gas enters the air outlet pipeline 51 of the centrifugal draught fan, and the air outlet pipeline 51 of the centrifugal draught fan can be connected with other series of gas processing equipment to carry out desulfurization and dust removal processing on the flue gas and then safely discharge. Fresh cold air enters the plate pieces of the pillow-shaped heat transfer plates 44 in the air-air heat exchanger 42 from a cold air inlet 47, and high-temperature hot air obtained after heat exchange flows out of a hot air outlet 48 and then enters the blower 3; the high-temperature hot air is sent into the movable hot blast stove 1 by the blower 3 to be used as combustion-supporting air, the preheating temperature of the combustion-supporting air is increased, the stable combustion range of the fuel can be expanded, and the higher the preheating temperature is, the larger the stable combustion range is.

In the process of heating the barrel 20 in the reaction kettle, the stirring mechanism of the direct-connection transmission single-shaft cutting type stirs the materials under the synergistic effect of all the components, and the stirring speed is 40-50 rpm. In addition, in order to prevent the bearings of the stirring paddle main shaft 24 from overheating, the stirring mechanism can be connected with a set of air-cooled water coolers 36 which can prevent the bearings from overheating, the air-cooled water coolers 36 are connected to the detachable cooling joint 34 through pipelines, and the bearings are cooled through the circulation of cooling water between a cooling water inlet 37 and a cooling water outlet 38.

The material begins to generate the material state change when being heated from normal temperature to about 450-500 ℃ in the horizontal thermal cracking reaction kettle, and a large amount of high-temperature thermal cracking gas begins to generate; the generated high-temperature pyrolysis gas flows along the oil gas outlet pipe 30 and then enters the connecting pipeline 41 of the air outlet port of the centrifugal fan under the air inducing action of the high-temperature resistant centrifugal fan 39. Then the high-temperature pyrolysis gas can sequentially enter a dechlorinating tank in a subsequent system for dechlorination, a stainless steel steam-water separation tank for steam-water separation, and then the clean and dry light oil gas enters a condensing system for condensing into oil. The non-condensable gases after safe treatment can be introduced into the mobile stove 1 for combustion. When thermal cracking is finished and the horizontal thermal cracking reaction kettle is cooled, the residues of the thermal cracking reaction such as carbon black and ash powder can be cleaned by opening the overhaul and slag discharge door 31 and then being externally connected with a matched mobile powder industrial dust collector; the collected carbon black can be recycled.

The above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby, and any modification made on the basis of the technical scheme according to the technical idea proposed by the present invention falls within the protection scope of the present invention; the technology not related to the invention can be realized by the prior art.

Claims

1. An energy-saving thermal cracking reaction kettle for treating organic solid waste comprises a reaction kettle outer barrel (14) and a reaction kettle inner barrel (20), and is characterized in that: the reaction kettle is characterized in that at least one group of U-shaped pipe members are arranged on the inner barrel (20) of the reaction kettle and comprise U-shaped pipes (25) arranged on the upper portion of an inner cavity of the inner barrel (20) of the reaction kettle, two opening ends of each U-shaped pipe (25) are respectively connected with the tail end of a flue gas inlet pipe (18) of each U-shaped pipe member and the starting end of a flue gas outlet pipe (26) of each U-shaped pipe member, the opening of the starting end of each flue gas inlet pipe (18) faces to the flowing direction of high-temperature flue gas, and the tail end of each flue gas outlet pipe (26) of each U-shaped pipe member is communicated with a.

2. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 1, characterized in that: a fine hole filter screen (19) made of 310S stainless steel and capable of filtering smoke dust is additionally arranged on the inner side of the opening of the starting end of the smoke inlet pipe (18) of the U-shaped pipe member.

3. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 1, characterized in that: the opening of the starting end of the flue gas inlet pipe (18) of the U-shaped pipe member is in an enlarged horn shape, and the tail end of the flue gas inlet pipe (18) of the U-shaped pipe member is connected with the inner barrel (20) of the reaction kettle in a welding or high-temperature resistant sealing manner and is communicated with one opening end of the U-shaped pipe (25).

4. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 1, characterized in that: the starting end of a flue gas outlet pipe (26) of the U-shaped pipe member is connected with the inner cylinder (20) of the reaction kettle in a welding or high-temperature resistant sealing manner and is communicated with the other opening end of the U-shaped pipe (25).

5. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 1, characterized in that: the flue gas inlet pipe (18) of the U-shaped pipe member, the U-shaped pipe (25) and the flue gas outlet pipe (26) of the U-shaped pipe member are made of seamless stainless steel 310s or 316L, the pipe diameters of the flue gas inlet pipe (18) of the U-shaped pipe member, the U-shaped pipe (25) of the U-shaped pipe member and the flue gas outlet pipe (26) of the U-shaped pipe member are larger than or equal to 80mm, and the wall thicknesses of the flue gas inlet pipe (18), the U-shaped pipe (25) of.

6. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 1, characterized in that: the flue gas inlet pipe (18) of the U-shaped pipe member and the flue gas outlet pipe (26) of the U-shaped pipe member are both arranged at one end of the barrel body (20) in the reaction kettle, which is adjacent to a high-temperature flue gas source.

7. The energy-saving thermal cracking reactor for treating organic solid wastes according to any one of claims 1 to 6, characterized in that: the inner wall inboard of the outer barrel of reation kettle (14) has arranged arc guide plate (17) that set up along the cauldron body axial, and the arc curved surface of arc guide plate (17) is facing to the flow direction setting of high temperature flue gas for the arc curved surface of arc guide plate (17) can block high temperature flue gas part and vertically water conservancy diversion to on the reation kettle inner tube body (20) that need heat.

8. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 7, wherein: the arc-shaped guide plates (17) are distributed on the inner wall of the outer barrel (14) of the reaction kettle at equal length and equal distance along the axial direction of the kettle body.

9. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 7, wherein: the included angle theta between the tangent line of the bottom end of the arc-shaped curved surface of the arc-shaped guide plate (17) and the axis of the kettle body is 30-40 degrees.

10. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 7, wherein: the front end of the arc-shaped guide plate (17) penetrates through the inner side refractory heat-insulating material layer in the composite refractory heat-insulating material and metal material layer (16) and is fixed on the inner wall of the outer side metal material layer in the composite refractory heat-insulating material and metal material layer (16) through a shaft support, and the composite refractory heat-insulating material and metal material layer (16) are positioned on the inner side of the inner wall of the outer barrel (14) of the reaction kettle.

11. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 10, wherein: the thickness of the refractory heat-insulating material layer in the composite refractory heat-insulating material and the metal material layer (16) is 25-30mm, and the thickness of the metal material layer is 6-8 mm.

12. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 7, wherein: the arc-shaped guide plate (17) is made of 316L stainless steel, the length L of the arc-shaped guide plate (17) is 300-500 mm, and the distance between the front arc-shaped guide plate and the rear arc-shaped guide plate (17) along the axial direction of the kettle body is 500-600 mm.

13. The energy-saving thermal cracking reactor for treating organic solid wastes according to any one of claims 1 to 6, characterized in that: the double-curved-surface-plate fin structure is characterized in that double-curved-surface-plate fins (21) arranged in an array mode are arranged on the circumferential outer wall of the inner barrel (20) of the reaction kettle, the double-curved-surface-plate fins (21) are arranged on the circumferential outer wall of the inner barrel (20) of the reaction kettle in an inclined mode of 30-45 degrees, the upper end face, the lower end face, the front side face and the rear side face of any double-curved-surface-plate fin (21) are curved surfaces, the curvatures are kept consistent, and the left end.

14. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 13, wherein: the double-curved-surface plate fins (21) are arranged in a row along the axial direction of the barrel (20) in the reaction kettle, and the double-curved-surface plate fins (21) in any row of the double-curved-surface plate fins (21) are all arranged in parallel.

15. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 14, wherein: any one row of the double curved surface plate fins (21) and one row of the double curved surface plate fins (21) on the left side of the double curved surface plate fins are arranged in a positive splayed shape, and the row of the double curved surface plate fins (21) and one row of the double curved surface plate fins (21) on the right side of the double curved surface plate fins are arranged in an inverted splayed shape; on the contrary, any row of the double curved plate fins (21) and one row of the double curved plate fins (21) on the left side of the double curved plate fins are arranged in an inverted splayed shape, and the row of the double curved plate fins (21) and one row of the double curved plate fins (21) on the right side of the double curved plate fins are arranged in a regular splayed shape.

16. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 14, wherein: the multiple rows of double-curved-surface plate fins (21) are uniformly distributed on the circumferential outer wall of the inner barrel (20) of the reaction kettle, and the curvature of the upper end surface and the lower end surface of each double-curved-surface plate fin (21) is equal to the curvature of an arc line of the outer surface of the inner barrel (20) of the reaction kettle, which is attached to the upper end surface and the lower end surface of each double-curved-surface plate.

17. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 14, wherein: the span direction interval of two adjacent hyperboloid plate fins (21) in the same row is equal to the curved surface chord length of the hyperboloid plate fins (21), and the center distance of two hyperboloid plate fins (21) in the adjacent row is equal to the curved surface chord length of the hyperboloid plate fins (21).

18. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 13, wherein: the height of the double-curved-surface plate fin (21) is 1/15-1/25 of the outer diameter of the cylinder (20) in the reaction kettle, the length of the double-curved-surface plate fin (21) is more than one time of the height of the double-curved-surface plate fin, and the thickness of each double-curved-surface plate fin (21) is 8-10 mm.

19. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 13, wherein: the curvature radius of the front side surface and the rear side surface of the hyperboloid plate fin (21) is the circumferential radius of the cylinder (20) in the reaction kettle.

20. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 13, wherein: the double-curved-surface plate fin (21) is made of 310s or 314 stainless steel, and the double-curved-surface plate fin (21) is fixed on the outer surface of the barrel (20) in the reaction kettle in a welding mode.

21. The energy-saving thermal cracking reactor for treating organic solid wastes according to any one of claims 1 to 6, characterized in that: the reaction kettle is characterized in that a direct-connection transmission single-shaft cutting type stirring mechanism is arranged on the inner barrel body (20), the stirring mechanism comprises a spiral cutting type paddle (23) arranged on a stirring paddle main shaft (24), two ends of the stirring paddle main shaft (24) extend out of the end of the inner barrel body (20) of the reaction kettle, and the stirring paddle main shaft (24) is driven by a motor gearbox direct-connection unit (33).

22. The energy efficient thermal cracking reactor for processing organic solid waste material of claim 21, wherein: the stirring paddle main shaft (24) is provided with two sections of alternating spiral cutting type blades (23) with the same length, one blade (23) is twisted by 180 degrees clockwise, the other blade (23) is twisted by 180 degrees anticlockwise, the diameter of any blade (23) is 700-900 mm, and the intersection part of the two blades (23) accounts for 15-18% of the length of the single blade (23).

23. The energy efficient thermal cracking reactor for processing organic solid waste material of claim 21, wherein: and the extending end of the stirring paddle main shaft (24) is respectively provided with a front bearing seat and a sealing assembly (13) of the stirring mechanism and a rear bearing seat and a sealing assembly (32) of the stirring mechanism.

24. The energy efficient thermal cracking reactor for processing organic solid waste material of claim 23, wherein: the extension end of the stirring paddle main shaft (24) is provided with a detachable cooling joint (34), and a cooling water inlet (37) and a cooling water outlet (38) of the detachable cooling joint (34) are respectively communicated with a water outlet and a water return port of the air-cooled water cooler (36) through pipelines.

25. The energy-saving thermal cracking reactor for treating organic solid wastes according to any one of claims 1 to 6, characterized in that: the hot air channel smoke outlet (27) at the top of the outer barrel (14) of the reaction kettle is communicated with a heat exchanger smoke inlet (45) of the gas-gas heat exchanger (42) through a smoke exhaust pipeline (28), a hot air outlet (48) of the gas-gas heat exchanger (42) is communicated with an inlet of the air blower (3) and an outlet of the air blower (3) is communicated with the movable hot air furnace (1), and high-temperature smoke output by the movable hot air furnace (1) is sent into a hot air channel (22) between the inner wall of the outer barrel (14) of the reaction kettle and the outer wall of the inner barrel (20) of the reaction kettle.

26. The energy efficient thermal cracking reactor for processing organic solid waste material of claim 25, wherein: a pillow-shaped heat transfer plate (44) is arranged in the air-air heat exchanger (42), cold air input from a cold air inlet (47) of the air-air heat exchanger (42) enters the plate pieces of the pillow-shaped heat transfer plate (44), and hot air after heat exchange flows out from a hot air outlet (48) and then enters the blower (3); high-temperature flue gas input from a flue gas inlet (45) of the heat exchanger enters an outer plate channel of the pillow-shaped heat transfer plate (44), and low-temperature flue gas after heat exchange flows out from a flue gas outlet (46) of the heat exchanger of the gas-gas heat exchanger (42).

27. The energy efficient thermal cracking reactor for processing organic solid waste material of claim 26, wherein: the heat exchanger exhanst gas outlet (46) is connected with the inlet end of a centrifugal draught fan (50) through a centrifugal draught fan air inlet pipeline (49), and the outlet end of the centrifugal draught fan (50) is provided with a centrifugal draught fan air outlet pipeline (51).

28. The energy efficient thermal cracking reactor for processing organic solid waste material according to claim 1, characterized in that: be equipped with on reation kettle feed end (10) of barrel (20) in the reation kettle feed end (12) and atmosphere protective gas entry (11), reation kettle exit end (29) and be equipped with oil gas outlet pipe (30) and overhaul and slag discharge door (31), oil gas outlet pipe (30) with be linked together at high temperature resistant centrifugation draught fan (39), and the outlet side of high temperature resistant centrifugation draught fan (39) is equipped with centrifugation draught fan air-out port connecting tube (41).