An external heating rotary kiln multi-burner oil sand retorting system

Abstract

The present application provides a kind of outside hot type rotary kiln multi-burner oil sand dry distillation system, including outside hot type rotary kiln, deslagging machine, two-stage condensing tower, primary condensing tower, spray tower and sedimentation tank;Spiral feeder is connected at the feed inlet of outside hot type rotary kiln, and outside hot type rotary kiln is provided with natural gas burner, and the hot air generated by natural gas burner combustion is preheated by heat exchanger, and the oil gas steamed out of outside hot type rotary kiln is sprayed into spray tower with water, part of which enters sedimentation tank for sedimentation, and the other part of oil gas mixture enters primary condensing tower and two-stage condensing tower by induced draft fan, and the oil-water mixture after condensation enters oil-water separator, and the recovered oil is stored, and the condensate is externally sent after reaching standard by three-stage oil separation pretreatment;The uncondensed non-condensable gas steamed out of outside hot type rotary kiln is sent into outside hot type rotary kiln by return air fan and is burned, to form energy cycle.The present application can handle viscous oil sand, oil sand containing corrosive gas, expand the feed range, and improve the equipment utilization.

Description

Technical Field

[0001] This invention belongs to the technical field of oil sand dry distillation equipment, specifically relating to an externally heated rotary kiln multi-burner oil sand dry distillation system. Background Technology

[0002] In the field of oil sands retorting, traditional equipment has the following shortcomings: 1. Insufficient adaptability to raw materials: Existing equipment is difficult to process sticky oil sand and oil sand containing corrosive gases, and the requirements for feeding are too fine, which limits the utilization rate of the equipment.

[0003] 2. Low heat transfer efficiency: The internal heating rotary kiln adopts a horizontal lifting plate arrangement, and the material is directly in contact with the flame after being lifted up, resulting in serious heat loss. In addition, there are no heat absorption plates on the cylinder wall, resulting in low heat utilization rate.

[0004] 3. High energy consumption and unstable temperature: The combustion chamber only uses aluminum silicate insulation cotton, which lacks heat absorption and release functions. Cold gas entering the kiln easily disturbs the temperature. At the same time, the waste heat is not utilized, resulting in a large consumption of natural gas.

[0005] 4. Defects in sealing and discharge: The fixed connection of the feeding part cannot adapt to thermal expansion and is difficult to adjust; the discharge sealing method is simple and easily causes dust leakage, which pollutes the environment.

[0006] 5. Poor environmental performance and energy waste: Non-condensable gases lack a recycling system, exhaust gas treatment costs are high, and energy is not recycled.

[0007] Based on this, an externally heated rotary kiln multi-burner oil sand dry distillation system is proposed. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an externally heated rotary kiln multi-burner oil sand dry distillation system to address the shortcomings of the prior art mentioned above.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an externally heated rotary kiln multi-burner oil sand dry distillation system, comprising: Externally heated rotary kiln, slag remover, secondary condenser, primary condenser, spray tower, and sedimentation tank; The externally heated rotary kiln is connected to a screw feeder at its feed inlet. The externally heated rotary kiln is equipped with a natural gas burner. The hot air generated by the natural gas burner is preheated by a heat exchanger to provide combustion air. The externally heated rotary kiln uses a two-stage interlocking mechanism for sealed feeding and is equipped with a slag discharge machine to prevent dust and improve the on-site environment.

[0010] The oil and gas vapors and water vapors distilled from the externally heated rotary kiln are sprayed through a spray tower. Part of the mixture enters a sedimentation tank for sedimentation, while the other part of the oil and gas mixture enters a primary condenser and a secondary condenser through an induced draft fan. The condensed oil and water mixture enters an oil-water separator. The recovered oil is stored, and the condensate is sent out after passing a three-stage oil separation pretreatment. The uncondensed non-condensable gas distilled from the externally heated rotary kiln is sent back into the externally heated rotary kiln for combustion by a return air fan, forming an energy cycle.

[0011] As a further explanation of the present invention, the front end of the screw feeder is also provided with a crusher, a scale conveyor, a belt scale and an elevator. The oil sand to be processed is fed into the screw feeder after being processed by the crusher, the scale conveyor, the belt scale and the elevator in sequence.

[0012] As a further explanation of the present invention, a waste heat utilization device is provided above the inlet of the screw feeder. The hot flue gas from the externally heated rotary kiln enters the waste heat utilization device to preheat the incoming oil sand and increase the temperature of the material.

[0013] As a further explanation of the present invention, the externally heated rotary kiln consists of a rotary kiln body, lifting plates, and a combustion chamber; The lifting plates are arranged obliquely inside the rotary kiln cylinder. The lower half of the combustion chamber is made of refractory castable and equipped with aluminum silicate insulation cotton. Refractory gratings are also installed inside the combustion chamber.

[0014] As a further explanation of the present invention, the externally heated rotary kiln is 14 meters long and 1.8 meters in diameter, and is made of 310S stainless steel, with horizontal reinforcing ribs welded to the high-temperature section of the externally heated rotary kiln.

[0015] Compared with the prior art, the present invention has the following advantages: This invention can process viscous oil sand and oil sand containing corrosive gases, expanding the feeding range and improving equipment utilization.

[0016] The thermal efficiency of this invention is greatly improved. The externally heated rotary kiln consists of a rotary kiln body, lifting plates and a combustion chamber. A refractory grid is installed in the combustion chamber, which improves the heat transfer efficiency by more than 30% and stabilizes the internal temperature at 850-900℃.

[0017] The present invention has outstanding energy-saving effect. The natural gas burner combined with waste heat utilization technology can save more than 10% of natural gas. At the same time, the design of refractory castable and refractory grid reduces temperature fluctuation and improves thermal stability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the internal lifting plate arrangement of the externally heated rotary kiln of the present invention; Figure 3 This is a schematic diagram of the combustion chamber and burner configuration of the present invention; Figure 4 This is a process flow diagram of oil-water separation and non-condensable gas treatment according to the present invention.

[0019] Explanation of reference numerals in the attached figures: 1-Crusher; 2-Scale plate conveyor; 3-Belt scale; 4-Elevator; 5-Screw feeder; 6-Externally heated rotary kiln; 6.1-Rotary kiln body; 6.2-Lifting plate; 6.3-Combustion chamber; 7-Natural gas burner; 8-Slag discharger; 9-Return air fan; 10-Secondary condenser; 11-Primary condenser; 12-Spray tower; 13-Induced draft fan; 14-Sedimentation tank; 15-Waste heat recovery device; 16-Oil-water separator. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the described embodiments are only a part of the embodiments of this application, not all of them. The specific embodiments described herein are only used to explain the invention and are not intended to limit the invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] like Figure 1-4 As shown, the present invention provides a technical solution: an externally heated rotary kiln multi-burner oil sand dry distillation system, comprising: Externally heated rotary kiln 6, slag discharger 8, secondary condenser tower 10, primary condenser tower 11, spray tower 12, and sedimentation tank 14; The feed inlet of the externally heated rotary kiln 6 is connected to a screw feeder 5. The front end of the screw feeder 5 is also equipped with a crusher 1, a scale conveyor 2, a belt scale 3, and an elevator 4. The oil sand to be processed is fed into the screw feeder 5 after being processed by the crusher 1, the scale conveyor 2, the belt scale 3, and the elevator 4 in sequence. This can stably and efficiently complete the material feeding work, laying a solid foundation for subsequent production.

[0022] The externally heated rotary kiln 6 consists of a rotary kiln body 6.1, a lifting plate 6.2, and a combustion chamber 6.3; The lifting plates 6.2 are arranged obliquely inside the rotary kiln body 6.1. The lower half of the combustion chamber 6.3 is made of refractory castable and equipped with aluminum silicate insulation cotton, which has both heat preservation and heat absorption and release functions, and can balance the temperature of the kiln body. In addition, a refractory grid is installed in the combustion chamber 6.3 to preheat the non-condensable gas that is being burned back, and to avoid the cold gas disturbing the temperature.

[0023] The externally heated rotary kiln 6 is 14 meters long and 1.8 meters in diameter. It is made of 310S stainless steel and has horizontal reinforcing ribs welded to the high-temperature section to prevent deformation and extend the warranty period.

[0024] The externally heated rotary kiln 6 is equipped with a natural gas burner 7, and there are 7 natural gas burners 7. This ensures a stable hot air temperature and prevents the flame from directly spraying into the rotary kiln body 6.1. The hot air generated by the combustion of the natural gas burner 7 is preheated by a heat exchanger to save more than 10% of natural gas.

[0025] A waste heat utilization device 15 is installed above the inlet of the screw feeder 5. The hot flue gas from the externally heated rotary kiln 6 enters the waste heat utilization device 15 to preheat the incoming oil sand and increase the temperature of the material.

[0026] The externally heated rotary kiln 6 uses a two-stage interlocking mechanism for sealed feeding and is equipped with a slag discharger 8, which can prevent dust and improve the on-site environment.

[0027] The oil and gas vapors and water vapors distilled from the externally heated rotary kiln 6 pass through the spray tower 12. Part of the mixture enters the sedimentation tank 14 for sedimentation, while the other part of the oil and gas mixture enters the primary condenser tower 11 and the secondary condenser tower 10 through the induced draft fan 13. The condensed oil and water mixture enters the oil-water separator 16. The recovered oil is stored, and the condensate is sent out after passing the three-stage oil separation pretreatment. The uncondensed non-condensable gas distilled from the externally heated rotary kiln 6 is sent back into the externally heated rotary kiln 6 for combustion via the return air fan 9, forming an energy cycle.

[0028] The experimental example is the dry distillation of oil sands from the Fengcheng oil sand mine in Karamay City, Xinjiang.

[0029] The oil sands mainly consist of quartz (50%–70%) and feldspar (10%–20%), with particle sizes mostly ranging from 0.1 to 0.5 mm. Clay minerals are primarily montmorillonite and illite (5%–15%), with a small amount of kaolinite. Other inorganic components include small amounts of carbonates, iron oxides, and trace metal elements. The oil sands have an average oil content of 8.9%, an average water content of 0.4%, and a crude oil density > 0.9 g / cm³. 3 It has high viscosity at room temperature, reaching thousands to tens of thousands of mPa·s, and moderate sulfur content, ranging from 0.5% to 2%.

[0030] After mixing and screening, the oil sand is transported to the hopper above the crusher 1 by a loader or belt. After being crushed, it is fed into the screw feeder 5 by the scale conveyor 2, belt scale 3 and elevator 4. Before feeding, the oil sand particles are crushed to less than 5mm. This device can process 500 tons of oil sand per day and the feeding speed is 20.8 tons / hour.

[0031] Material is fed into the externally heated rotary kiln 6 by the screw feeder 5. The externally heated rotary kiln 6 rotates at low speed, and the lifting plates 6.2 lift the material and roll it along the inner wall of the rotary kiln body 6.1, ensuring that the material has maximum contact with the inner wall of the rotary kiln body 6.1 to absorb heat. Seven separate natural gas burners 7 outside the externally heated rotary kiln 6 work synchronously. The hot air generated by combustion is preheated by the combustion air through a heat exchanger. The flame does not directly contact the material to avoid pollution. The refractory castable in the lower half of the combustion chamber 6.3 absorbs heat and releases it evenly, maintaining a stable temperature of 850-900℃ inside the kiln. During the equipment commissioning phase, the combustion chamber 6.3 mainly uses externally supplied natural gas, with a daily natural gas consumption of 2500m³. 3 During the stable production phase, the equipment will primarily utilize the non-condensable gases generated by the equipment itself.

[0032] The heating program, heating rate, and products of the distillation furnace are as follows: The temperature ranges from 35℃ to 100℃, with a heating rate of 1.5℃ / min. The product is adsorbed water. 100℃-500℃, heating rate 6℃ / min, products are light oil and dry distillation gas; 500℃-800℃, heating rate 5℃ / min, products are semi-coke and dry distillation gas; >800℃, heating rate 5℃ / min, product is solid waste.

[0033] To prevent coking, the heating rate during the production of light oil is relatively high, reaching 6°C / minute.

[0034] After dry distillation, the material falls from the tail outlet of the externally heated rotary kiln 6 into the kiln head hood. It is then sealed and discharged through a two-stage interlocking mechanism. The scraper-type slag discharger 8 transports the material to subsequent processing equipment. The entire process is dust-free, ensuring a clean on-site environment.

[0035] After the evaporated oil and gas and water pass through the spray tower 12, part of it enters the sedimentation tank 14 for sedimentation, and the other part of the oil and gas mixture enters the primary condenser tower 11 and the secondary condenser tower 10 through the induced draft fan 13. The condensed oil and water mixture enters the oil-water separator 16. The recovered oil is stored, and the condensate is sent out after passing the three-stage oil separation pretreatment. The uncondensed non-condensable gas, after being de-misted by a demister to remove water mist and oil mist, is sent to the internal combustion chamber 6.3 of the externally heated rotary kiln 6 by the return air fan 9, providing heat energy for the rotary kiln heating of the externally heated rotary kiln 6 and realizing energy recycling.

[0036] The main products of this pyrolysis system are: adsorbed water, light oil, pyrolysis gas, semi-coke, and solid waste.

[0037] Adsorbed water: The original water content of the oil sand is 0.4%, which is completely desorbed at 35~100℃. The main components are free water and mineral adsorbed water, with almost no impurities (because the decomposition temperature of organic matter has not been reached).

[0038] Light oil: mainly consists of light hydrocarbons (alkanes C) decomposed from asphalt. 10 The following (including cycloalkanes and some aromatic hydrocarbons), due to the rapid heating rate (which inhibits coking), the yield of light oil is about 35% to 40% of the total asphalt.

[0039] Dry distillation gas: mainly comes from the pyrolysis (volatilization of small molecules) of hydrocarbons in asphalt and the decomposition of sulfur and nitrogen compounds, accounting for 15% to 20% of the total asphalt volume.

[0040] Semi-coke: The incompletely decomposed heavy components (colloids, asphaltenes and some condensed aromatics) in asphalt, accounting for 20% to 30% of the total asphalt.

[0041] Solid waste: mainly consists of the original mineral matrix of oil sands (accounting for 90.7% of the total amount of oil sands) and the residues after the high-temperature decomposition of semi-coke (about 70% of the semi-coke is converted into carbonaceous matter in solid waste).

[0042] Through the above-mentioned system structure and process design, this invention achieves efficient, energy-saving and environmentally friendly operation of oil sand dry distillation, solves the core defects of existing technologies, and has significant technological innovation and industrial application value.

[0043] When a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0044] The directional terms "inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself. The terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," or "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0045] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, and the spatial relative descriptions used herein will be interpreted accordingly.

[0046] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, and "several" means one or more, unless otherwise explicitly specified.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An externally heated rotary kiln multi-burner oil sand dry distillation system, characterized in that, include: External heating rotary kiln (6), slag discharger (8), secondary condenser (10), primary condenser (11), spray tower (12) and sedimentation tank (14). The externally heated rotary kiln (6) is connected to a screw feeder (5) at its feed inlet. The externally heated rotary kiln (6) is equipped with a natural gas burner (7). The hot air generated by the combustion of the natural gas burner (7) is preheated by a heat exchanger to aid combustion air. The externally heated rotary kiln (6) adopts a two-stage interlocking mechanism for sealed feeding and is equipped with a slag discharge machine (8); this can prevent dust and improve the on-site environment. The oil and gas vapors and water vapors distilled from the externally heated rotary kiln (6) pass through the spray tower (12). Part of the mixture enters the sedimentation tank (14) for sedimentation, while the other part of the oil and gas mixture enters the primary condenser (11) and the secondary condenser (10) through the induced draft fan (13). The condensed oil and water mixture enters the oil-water separator (16). The recovered oil is stored, and the condensate is sent out after passing the three-stage oil separation pretreatment. The non-condensable gas distilled out by the externally heated rotary kiln (6) is sent into the externally heated rotary kiln (6) by the return air fan (9) for combustion, forming an energy cycle.

2. The externally heated rotary kiln multi-burner oil sand dry distillation system according to claim 1, characterized in that, The front end of the screw feeder (5) is also equipped with a crusher (1), a scale conveyor (2), a belt scale (3) and an elevator (4). The oil sand to be processed is fed into the screw feeder (5) after being processed by the crusher (1), the scale conveyor (2), the belt scale (3) and the elevator (4).

3. The externally heated rotary kiln multi-burner oil sand dry distillation system according to claim 1, characterized in that, The screw feeder (5) is equipped with a waste heat utilization device (15) above the inlet. The hot flue gas from the externally heated rotary kiln (6) enters the waste heat utilization device (15) to preheat the incoming oil sand and increase the temperature of the material.

4. The externally heated rotary kiln multi-burner oil sand dry distillation system according to claim 1, characterized in that, The externally heated rotary kiln (6) consists of a rotary kiln body (6.1), a lifting plate (6.2), and a combustion chamber (6.3); The lifting plate (6.2) is arranged obliquely inside the rotary kiln body (6.1). The lower half of the combustion chamber (6.3) is made of refractory castable and is equipped with aluminum silicate insulation cotton. Refractory grids are also installed inside the combustion chamber (6.3).

5. The externally heated rotary kiln multi-burner oil sand dry distillation system according to claim 1, characterized in that, The externally heated rotary kiln (6) is 14 meters long and 1.8 meters in diameter. It is made of 310S stainless steel and has horizontal reinforcing ribs welded to the high-temperature section of the externally heated rotary kiln (6).

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