An oil shale retorting device with time-sharing operation

Abstract

This solution discloses a time-sharing oil shale retorting device, which includes three fixed time-sharing retorting furnaces and a retorting gas treatment unit connected thereto; the retorting furnace includes a furnace body, a sealed water basin located below the furnace body, as well as a retorting gas outlet and an ash discharge port. A tray is provided on the upper side of the sealed water basin, and a raw material bin is provided above the furnace body; a flue gas inlet and a combustion gas outlet are provided on both side walls of the furnace body; the flue gas inlet is simultaneously connected to the atmosphere and the combustion gas outlet of the adjacent furnace body; an air regulating valve is provided at the connection between the flue gas inlet and the atmosphere, and a flue gas shut-off valve is provided at the combustion gas outlet; a retorting gas shut-off valve is provided on the retorting gas outlet. This solution avoids the problem that the shale retorting in the prior art with simple shaping generates fragmentation during the retorting process, which affects the retorting; at the same time, it is environmentally friendly and easy to operate automatically.

Description

Technical Field

[0001] The present invention belongs to the technical field of shale retorting, and particularly relates to a time-segmented oil shale retorting device for retorting small particle oil shale. Background Art

[0002] At present, in the technical field of above-ground retorting of oil shale, the gas heat carrier retorting technology is relatively mature. In particular, due to the characteristics of the Fushun retorting process, such as the ability to utilize the heat of fixed carbon to retort low-grade shale, self-sufficiency in heat, and relatively low operating costs, it is widely used in industrial production. However, since a certain amount of small particle fine powder tailings are generated during the raw material crushing and screening process in the gas heat carrier retorting technology and cannot be fully used for retorting, it results in partial waste of resources and also increases the mining and retorting costs.

[0003] In recent years, in order to improve the utilization rate of shale resources, a large amount of technical research has been invested in the retorting utilization of small particle tailing shale below 12 mm that was discarded before and in improving the oil yield, and gratifying achievements have been made. As is well known, currently small particle shale cannot be directly retorted and must be processed after being formed by pressing or the like. However, the product formed after simple pressing is particularly loose and is extremely easy to break during the retorting process, resulting in the inability to continuously retort. Although it has been successful in retorting small particle powdered shale by adding additives to form it and then using the Fushun retorting process technology, the forming cost is relatively high, the oil yield is relatively low, and there is no economic value.

[0004] There is also a method, usually called the "Sanbao Furnace" method, which adopts simple forming of powdered shale (without adding additives), loading it into a basket and putting it into the furnace, then burning the upper basket to supply heat for the retorting of the lower basket. After the upper basket finishes burning and the lower basket finishes retorting, the upper basket is taken away, and the lower basket is moved to the upper part as the burning part, and a new basket is added below. This method has also been successful in retorting. Although the simple forming cost of this method is relatively low and the oil yield is relatively high, the equipment and the retorting process are relatively complex, the retorting operation cost is relatively high, hydrocarbon vapor will leak during the process of swapping the upper and lower baskets, causing certain pollution to the environment, and there are disadvantages such as a relatively small retorting processing capacity and it is not easy to realize industrial automation operation and large-scale application, so its application prospect is limited to a certain extent. Summary of the Invention

[0005] The purpose of the present invention is to provide a time-segmented oil shale retorting device to achieve economic and environmental protection retorting of small particle shale, so as to solve the problems of relatively high cost, low oil yield, and environmental pollution in retorting fine powdered shale in the prior art.

[0006] The present invention is realized through the following technical solutions: A time-segmented oil shale retorting device, characterized in that: it includes three fixed time-segmented retorting furnaces and a retorting gas treatment unit connected thereto;

[0007] The retorting furnace includes a furnace body, a sealed water basin located below the furnace body. A retorting gas outlet and an ash discharge port are provided below the sealed water basin. A tray is provided on the upper side of the sealed water basin, and a raw material bin and a feeding valve are provided above the furnace body. Smoke inlets and combustion gas outlets are oppositely arranged on both side walls of the furnace body. The smoke inlet is communicated with the atmosphere and the combustion gas outlet of an adjacent furnace body, and the combustion gas outlet is communicated with the smoke inlet of another adjacent furnace body. An air regulating valve is provided at the connection between the smoke inlet and the atmosphere, and a smoke switch valve is provided at the combustion gas outlet. A retorting gas switch valve is provided on the retorting gas outlet.

[0008] Further: The retorting gas treatment unit includes an intercooling recovery device, a cooling tower and a clean water pump connected in series. The inlet of the intercooling recovery device is communicated with the retorting gas outlet. The liquid outlet of the intercooling recovery device is communicated with an oil-water separation tank. The gas outlet is connected to a waste gas combustion waste heat utilization device through a gas blower. A combustion gas control valve and a vent valve are provided on the pipeline connecting the gas blower and the waste gas combustion waste heat utilization device.

[0009] Further: The tray is a deflecting tray. The tray is provided with pores communicated with the retorting gas outlet, and the tray is connected to a water basin ash discharger.

[0010] Further: An annular furnace inlet gas distributor is provided on the upper furnace wall inside the retorting furnace, and an annular gas outlet collector is provided on the middle furnace wall.

[0011] Further: The air inlet end of the upper part is connected to its own water basin closed cavity by a pipeline, and a combustion air regulating valve is provided in the middle.

[0012] Further: The sealed water basin is a rotating water basin, which is driven by a rotating motor arranged outside.

[0013] The advantages of the present invention are as follows: This device uses three fixed time-sharing retort furnaces to automatically complete the processes of retorting → combustion → cooling, slag discharging, and feeding in different time periods respectively, and continuously and automatically alternates to complete the retorting task in a cycle. During the retorting and combustion processes, the materials are relatively stationary in the furnace, avoiding the economic and technical problems of retorting affected by the low thermal strength after heating and the fragmentation phenomenon caused by the flow of materials in the furnace during the retorting process of powdered shale in the Fushun retorting process after simple shaping (without adding additives to reduce the shaping cost). At the same time, the process switching of retorting, combustion, and cooling, slag discharging, and feeding in different time periods is realized through valve switching pipeline control. There is no external leakage of hydrocarbon steam during the entire retorting process, avoiding the problem of environmental pollution caused by the inevitable external leakage of hydrocarbon steam during the process of placing a new shale basket, removing the ash basket after combustion, and moving the semi-coke in the lower basket after retorting to the upper part for combustion in the Sanbao furnace. At the same time, the fixed time-sharing retorting device operates fully automatically from feeding, switching in each time period to slag removal, with a simple device structure and being easy to realize industrial scale-up application and other characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a system diagram of the fixed time-sharing retorting device;

[0015] Figure 2 is a fixed time-sharing retort furnace;

[0016] Figure 3 is Figure 2 a sectional view taken at A of

[0017] Figure 4 is Figure 2 a sectional view taken at B of

[0018] Explanation of the numbers in the figure: 1 is the retort furnace, 2 is the retort gas treatment unit, 3 is the furnace body, 4 is the water basin, 5 is the retort gas outlet, 6 is the tray, 7 is the raw material bin, 8 is the flue gas inlet, 9 is the combustion gas outlet, 10 is the air regulating valve, 11 is the flue gas shut-off valve, 12 is the retort gas shut-off valve, 13 is the intermediate cooling recovery device, 14 is the cooling water tower, 15 is the clean water pump, 16 is the oil-water separation tank, 17 is the gas blower, 18 is the waste gas combustion waste heat utilization device, 19 is the combustion gas control valve, 20 is the gas distributor, and 21 is the outlet gas collector. DETAILED DESCRIPTION OF THE INVENTION

[0019] As Figures 1-4 shown, a time-sharing oil shale retorting device of the structure of the present invention includes three fixed time-sharing retort furnaces 1, namely Furnace A, Furnace B, and Furnace C; and a retort gas treatment unit 2 connected thereto; the material retorting process in each retort furnace includes three stages, namely the retorting stage, the combustion stage, and the cooling, slag discharging, and feeding stage (abbreviated as the slag discharging stage), and the three retort furnaces in this solution are in different stages of the distillation range (i.e., time-sharing) at the same time.

[0020] The retorting furnace 1 includes a furnace body 3, a rotatable water basin 4 with an ash discharge port located below the furnace body, a retorting gas outlet 5 provided below the water basin, a tray 6 provided on the water basin at the position of the inner axis of the furnace body, and a raw material bin 7 with a feed valve provided above the furnace body; a flue gas inlet 8 and a combustion gas outlet 9 are oppositely arranged on both side walls of the furnace body, and their preferred positions are Figure 1 divided into left and right sides in the middle and arranged one above the other (in the middle of the furnace body); the flue gas inlet is simultaneously communicated with the atmosphere and the combustion gas outlet of the adjacent previous furnace body, and the combustion gas outlet is communicated with the flue gas inlet of the next adjacent furnace body; an air regulating valve 10 is provided at the connection of the flue gas inlet and the atmosphere, and a flue gas shut-off valve 11 is provided at the combustion gas outlet; a retorting gas shut-off valve 12 is provided on the retorting gas outlet.

[0021] The retorting gas treatment unit can have the same structure as that in the prior art. The specific structure of this solution includes an intercooling recovery device 13, a cooling tower 14, and a clean water pump 15 connected in series. The intercooling recovery device is cooled by the clean water pump, its inlet is communicated with the retorting gas outlet for introducing retorting gas, its liquid outlet is communicated with an oil-water separation tank 16, and its gas outlet is communicated with an exhaust gas combustion waste heat utilization device 18 through a gas blower 17. A combustion gas control valve 19 and a vent valve are provided on the pipeline connecting the gas blower and the exhaust gas combustion waste heat utilization device.

[0022] The material carbonization process in the carbonization furnace of this solution is as follows: In the furnace body, first, simply formed powdered shale is added from the upper feed inlet. After the feeding is completed, high-temperature flue gas (prepared by heating air or introduced from the system) enters the furnace body from the flue gas inlet, and carbonizes the powdered shale from the upper part downwards. Under the suction of the gas blower, the carbonization oil gas is absorbed by the gaps on the lower tray in the furnace and exported from the carbonization gas outlet, and enters the carbonization gas treatment unit through the carbonization gas outlet switch valve for treatment and recovery. In the carbonization gas treatment unit, it first passes through the indirect cooling recovery device, and the oil gas forms a gas-liquid two-phase state through the indirect cooling recovery device, and then is separated. The liquid phase is introduced into the oil-water separation tank for separation to obtain the corresponding products, and the separated gas is sent to the gas combustion waste heat utilization device through the gas control valve under the traction of the gas blower. After the carbonization stage is completed, it enters the combustion stage. At this time, the carbonization gas outlet switch valve is closed and the flue gas switch valve is opened. At this time, air (or flue gas) enters the gas distributor 20 at the upper part of the carbonization furnace through the air regulating valve, and is collected by the outlet gas collector 21 and exported from the combustion gas outlet after being heated by combustion or contacting and exchanging heat with the ash residue after combustion in the furnace, absorbing the heat generated by the combustion of the carbonization residue. After the combustion is completed, it enters the cooling, slag discharging and feeding stage. The water basin and the tray are rotated by the rotary drive motor. The tray is a deflected tray, that is, it is not a shape with a relatively axisymmetric shape. Therefore, during rotation, it plays a good role in stirring the ash residue, which is beneficial to discharging the residual matter after combustion in the furnace, improving the ash discharging efficiency and preventing ash bridging, etc. After the slag discharging is completed, the ash discharging is closed, and new materials are introduced from the inlet to start the next cycle process. During the whole process, except for the feeding and slag discharging processes, there is no connection with the outside at other times, and there is no risk of hydrocarbon gas discharge.

[0023] The retorting device and process described in this solution will be further described below. It includes three fixed-time retorting furnaces, namely Furnace A, Furnace B, and Furnace C, which are arranged in sequence. Smoke gas shut-off valves A1, B1, and C1, combustion air regulating valves A2, B2, and C2, and retorting gas outlet shut-off valves A3, B3, and C3 are respectively provided on each furnace body. It also includes an intermediate cooling and recovery device with a gas blower and a waste heat utilization device for gas combustion. Each device is connected by pipelines and electric control valves. The materials are automatically controlled by electric valves according to a set program to complete different processes in the three retorting furnaces, that is, the tasks of retorting → combustion → cooling, slag discharging, and feeding; the specific working process is as follows: When Furnace A is in the retorting period, Furnace B is in the cooling, slag discharging, and feeding period, and Furnace C is in the combustion period; at this time, the combustion air regulating valve (B1 open) at the upper part of Furnace B is opened. Driven by the power of the gas blower, the air in the closed cavity of the water basin in Furnace B enters the gas distributor at the upper part of the furnace through the air regulating valve (B1), contacts and exchanges heat with the ash after combustion in Furnace B, and is then exported from the combustion gas outlet at the middle part of Furnace B (B2 open) and enters the upper part of Furnace C. At this time, the semi-coke after retorting in Furnace C contacts the preheated air and starts to burn gradually from the upper layer to the lower layer in Furnace C. The high-temperature flue gas generated by combustion is exported from the combustion gas outlet at the middle part of Furnace C (C2 open) and enters the upper part of Furnace A to start shale retorting. The retorting oil and gas descend in the furnace and are exported from the retorting gas outlet through the gaps on the trays at the lower part of Furnace A. Through the retorting gas outlet shut-off valve of Furnace A (A3 open), it enters the intermediate cooling and recovery device. The oil and gas pass through the intermediate cooling and recovery device to separate the gas and water, and then enter the waste heat utilization device for gas combustion through the inlet and outlet of the gas blower under the traction of the gas blower and through the combustion gas regulating valve. At the same time, the waste residue after combustion in Furnace B drives the water basin and the tray to rotate through the water basin driving device, so that the ash at the upper part of the furnace falls into the water basin, is further cooled, and then discharged outside the furnace. The new material is automatically loaded into the furnace through the high-temperature feeding valve, completes the cooling, slag discharging, and feeding tasks, and waits to enter the next retorting period.

[0024] Preferably: The fixed-time retorting furnace includes a furnace body metal shell structure with a circular shape. There is a feeding port at the furnace top, a flue gas (air) inlet, an upper-layer temperature control thermocouple, a combustion gas outlet at the middle part, a middle-layer temperature control thermocouple, a water basin and a water basin rotation driving device at the lower part, and a retorting gas outlet at the lower part of the water basin.

[0025] Preferably: Heat insulation and refractory materials are provided in the furnace. A circular inlet gas distributor is provided on the upper furnace wall inside the furnace, a circular outlet gas collector is provided on the middle furnace wall inside the furnace, a circular deflection tray is provided at the lower part of the furnace, and pores are provided on the tray. The inlet gas distributor is a circular pipe, and ventilation openings are provided on the pipe. The pipe is connected to the flue gas inlet. The outlet gas collector is similar in structure to the inlet gas distributor and will not be elaborated here.

[0026] Preferably, the devices are connected by pipelines and electric valves. Specifically, the middle combustion gas outlet of the fixed time-sharing retort furnace is connected to the air inlet at the upper part of another adjacent retort furnace by a pipeline, and a flue gas shut-off valve is provided in the middle; the air inlet end at the upper part of the retort furnace is connected to the water basin closed cavity by a pipeline, and a combustion air regulating valve is provided in the middle; the retort gas outlet end at the lower part of the retort furnace is connected to the retort gas inlet end of the indirect cooling and recovery device by a pipeline, and a retort gas shut-off valve is provided on one side of the retort gas outlet end; the retort gas outlet end of the indirect cooling and recovery device is connected to the inlet end of the gas blower by a pipeline, and the outlet end of the gas blower is connected to the gas inlet end of the gas combustion waste heat utilization device by a pipeline, and a combustion gas regulating control valve is provided in the middle.

[0027] It should be noted that by controlling the time and speed of each stage, it is possible to synchronously carry out different stages in three retort furnaces. In addition, in order to achieve effective gas circulation, devices such as air pumps can be added behind the corresponding valve bodies, or gas buffer structures can be set on the pipelines. In summary, in this solution, only the improved parts relative to the prior art are described in detail, and the structures identical to the prior art or well-known to those skilled in the art are not elaborated. Those skilled in the art can implement this solution based on the prior art.

[0028] The retorting device of the present invention has the following advantages:

[0029] (1) Since the materials are always in a static state in the furnace during the entire retorting and combustion processes, powdered shale can be put into the furnace for retorting after simple shaping (shaping without additives), avoiding the phenomenon that the materials are broken due to flow extrusion in the furnace during the retorting process in the existing Fushun furnace, which affects the retorting, thereby reducing the retorting cost and enabling 100% retorting utilization of shale resources;

[0030] (2) Since this device uses three fixed time-sharing retort furnaces to complete the entire processes of retorting, combustion, cooling, slag discharging, and feeding at different times respectively, and operates completely in a closed state during the process, without pollution, avoiding the phenomenon that hydrocarbon vapor leaks during the switching process of the existing Sanbao furnace's retorting method, where the upper basket is taken away after the upper basket finishes burning and the lower basket finishes retorting, the lower basket is moved to the upper part for combustion, and a new basket is re-added below, which causes certain pollution to the environment;

[0031] (3) Since a deflection tray is provided in the lower part of the fixed time-sharing retort furnace, and the deflection tray rotates along with the water basin during the slag discharging process, the coke blocks formed by combustion in the upper part of the furnace can be broken and fall into the water basin and be smoothly discharged outside the furnace, avoiding the phenomenon that coke blocks are formed in the basket of the existing Sanbao furnace and cannot be poured out of the basket, which affects the normal operation of the equipment;

[0032] (4) Since this device uses electric valves to control the on / off of each pipeline and can be automatically switched according to a program, it has a high degree of automation, low operating costs, and is easy to scale up for industrial production;

[0033] (5) Since this device introduces high-temperature gas from the upper part of the retort furnace during the retorting period and gradually retorts downward, the relatively high-density oil gas generated during the retorting process moves downward. The direction of the gas flow is the same as the gravity direction of the relatively high-density oil gas, and it is relatively easy to be exported from the retort gas outlet at the bottom of the retort furnace. Even if the export capacity of the gas blower is insufficient, there will be no occurrence of oil burning or carbonization of oil, thus improving the oil production rate;

[0034] (6) Since the power of the combustion air entering the upper part of the retort furnace during the combustion period of this device comes from the kinetic energy of the same gas blower, it is easy to control, safe and reliable.

Claims

1. A time - segmented oil shale retorting device, characterized in that: It includes three fixed time - segmented retorting furnaces and a retorting gas treatment unit connected thereto; the retorting furnace includes a furnace body, a sealed water basin located below the furnace body, a retorting gas outlet and an ash discharge port are arranged below the sealed water basin, a tray is arranged on the upper side of the sealed water basin, a raw material bin and a feeding valve are arranged above the furnace body; a flue gas inlet and a combustion gas outlet are oppositely arranged on both side walls of the furnace body; the flue gas inlet is connected to the atmosphere and the combustion gas outlet of the adjacent furnace body, and the combustion gas outlet is connected to the flue gas inlet of another adjacent furnace body; an air regulating valve is arranged at the connection of the flue gas inlet and the atmosphere, and a flue gas switch valve is arranged at the combustion gas outlet; a retorting gas switch valve is arranged on the retorting gas outlet; the tray is a deflecting tray, and pores connected to the retorting gas outlet are arranged on the tray, and the tray is connected to a water basin ash discharger; an annular gas distributor for inlet gas is arranged on the upper inner wall of the retorting furnace, and an annular gas collector for outlet gas is arranged on the middle inner wall; the air inlet end at the upper part is connected to its own water basin closed cavity by a pipeline, and a combustion air regulating valve is arranged in the middle.

2. The time - segmented oil shale retorting device according to claim 1, characterized in that: The retorting gas treatment unit includes an inter - cooling recovery device, a cooling tower and a clean water pump connected in series. The inlet of the inter - cooling recovery device is connected to the retorting gas outlet, the liquid outlet of the inter - cooling recovery device is connected to an oil - water separation tank, the gas outlet is connected to an exhaust gas combustion waste heat utilization device through a gas blower, and a combustion gas control valve and a vent valve are arranged on the pipeline connecting the gas blower and the exhaust gas combustion waste heat utilization device.

3. The time - segmented oil shale retorting device according to claim 1, characterized in that: The sealed water basin is a rotating water basin, which is driven by a rotating motor arranged outside.

Images