Multi-working-condition switching fixed bed gasifier

Abstract

The utility model discloses a multi-working-condition switching fixed bed gasifier which comprises a gasifier body, a feeding port is formed in the top of the gasifier body, an ash tray is arranged at the bottom of the gasifier body, the ash tray is connected with an upper suction air inlet, and a fuel gas outlet and a lower suction air inlet are sequentially formed in the side wall of the gasifier body from top to bottom. Wherein the fuel gas outlet is connected with the cyclone dust collector; the updraught air inlet is connected with an air blower through a first three-way valve and a second three-way valve which are connected in series; and the lower suction air inlet is connected with the second three-way valve. The utility model provides a biomass fixed bed gasification device capable of being used for producing hydrogen, which can be switched to three working conditions of upper part lower suction air gasification, lower part upper suction air gasification and water vapor gasification, can be used for producing biomass air fuel gas and hydrogen-rich fuel gas, and can be used for improving the economical efficiency and efficiency of biomass gasification hydrogen production. Biomass air fuel gas and pressure swing adsorption desorption gas can be sent to a boiler to be combusted and then used for heat supply or power generation, and hydrogen-rich fuel gas is purified for hydrogen production through a pressure swing adsorption procedure.

Description

Technical Field

[0001] The utility model relates to the field of biomass gasification, in particular to a fixed bed gasifier capable of switching between multiple working conditions. Background Art

[0002] Biomass gasification technology is one of the feasible technologies that can achieve efficient and clean utilization of biomass resources, and will play an increasingly important role in the conversion process of biomass resources. At present, the biomass fixed bed gasification technology is highly mature and has been put into industrial operation. However, the hydrogen content in the fixed bed gasifier fuel gas is 18%, and carbon monoxide (25-30%). After the conversion reaction, the hydrogen content in the fuel gas still does not exceed 35%. Compared with hydrogen extraction from coke oven gas and natural gas, the hydrogen content in the raw gas is too low to meet the economic requirements. Utility Model Content

[0003] The utility model aims to provide a fixed bed gasification furnace with multi-operating mode switching to solve the problems raised in the above-mentioned background technology.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A fixed-bed gasification furnace with multi-operating-mode switching comprises a furnace body, wherein a feeding port is provided at the top of the furnace body and an ash pan is provided at the bottom, the ash pan is connected to an upper air inlet, and the side walls of the furnace body are provided with a gas outlet and a lower air inlet in sequence from top to bottom; wherein the gas outlet is connected to a cyclone dust collector; the upper air inlet is connected to a blower via a first three-way valve and a second three-way valve connected in series; and the lower air inlet is connected to the second three-way valve.

[0006] A further solution: a valve port of the first three-way valve is connected to a steam source.

[0007] A further solution: a third three-way valve is connected to the top of the cyclone dust collector; the third three-way valve is respectively connected to an air gas pipeline and a water gas pipeline.

[0008] A further solution is that the number of the downward air inlets is at least three, which are evenly arranged along the circumference of the side wall of the furnace body; an air intake duct is provided in the downward air inlet, and the air outlet end of the air intake duct is horizontal and has a downward section.

[0009] A further solution: the outlet end of the air inlet pipe forms an angle of -° with the center line of the furnace body.

[0010] A further solution: the side wall of the furnace body includes an inner interlayer and an outer interlayer, the gas outlet is connected to the outer interlayer, and the upward air inlet is connected to the inner interlayer.

[0011] A further solution: there is a material storage space above the air intake pipe.

[0012] A further solution is that a temperature sensor is also arranged in the furnace body.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] The utility model provides a biomass fixed bed gasification device that can be used for hydrogen production. It can be switched to three working conditions: upper downward air suction gasification, lower upward air suction gasification, and water vapor gasification. It can also produce biomass air fuel gas and hydrogen-rich fuel gas, which can improve the economy and efficiency of biomass gasification hydrogen production. The biomass air fuel gas and pressure swing adsorption analysis gas can be sent to the boiler for combustion and then used for heating or power generation. The hydrogen-rich fuel gas is purified through the pressure swing adsorption process to produce hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a side sectional view of the utility model;

[0016] Figure 2 It is a top view of the furnace body in the utility model;

[0017] In the figure: 1-furnace body, 2-feeding port, 3-ash tray, 4-upper air inlet, 5-gas outlet, 6-lower air inlet, 7-cyclone dust collector, 8-first three-way valve, 9-second three-way valve, 10-blower, 11-third three-way valve, 12-air gas pipeline, 13-water gas pipeline, 14-intake pipeline, 15-inner interlayer, 16-outer interlayer. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0019] In the description of the present utility model, it should be noted that the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.

[0020] See also Figure 1-2A fixed bed gasifier with multi-mode switching comprises a furnace body 1, wherein a charging port 2 is arranged on the top of the furnace body 1, an ash tray 3 is arranged on the bottom, an upper air inlet 4 is connected to the ash tray 3, and a gas outlet 5 and a lower air inlet 6 are arranged on the side wall of the furnace body 1 from top to bottom; wherein the gas outlet 5 is connected to a cyclone dust collector 7; the upper air inlet 4 is connected to a blower 10 through a first three-way valve 8 and a second three-way valve 9 in series; the lower air inlet 6 is connected to the second three-way valve 9, so that the air at the blower outlet is delivered to the upper air inlet 4 or the lower air inlet 6 in different time periods, so as to realize time-sharing gasification; the furnace body 1 is cylindrical, the upper part of the furnace body 1 is a cyclone air inlet self-feeding lower air gasifier, the gas is drawn out from the interlayer channel of the gasifier in the middle, and the lower part of the furnace body 1 is an upper reaction zone for air heat storage gasification and water-coal gasification to produce hydrogen. The gas is drawn out from the gas outlet 5, and the hydrogen-rich water gas and air gas are respectively transported to the pressure swing adsorption section and the gas boiler through the third three-way valve 11. The air supply is switched between the upper downward suction and the lower upward suction, and at different times, according to different working conditions, between heat storage gasification and water gas gasification, thereby realizing a multi-operating mode in which the hydrogen-rich gas and air gas alternately flow out of the furnace body 1 through different outlets.

[0021] Furthermore, there are four downward air inlets 6, which are evenly arranged along the circumference of the side wall of the furnace body 1; an air intake pipe 14 is provided in the downward air intake pipe 6, and the air outlet end of the air intake pipe 14 is horizontal and has a downward section. The air outlet end of the air intake pipe 14 forms an angle of 15-30° with the center line of the furnace body 1, and the air enters the furnace through the rotating nozzles formed by the four air intake pipes 14, forming a stable downward swirling airflow, ensuring balanced air intake of the downward air intake gasifier at the upper part of the furnace body 1, and uniform distribution of the fire layer.

[0022] Furthermore, the storage space above the air inlet pipe 14 is used as a feeder to introduce biomass materials into the gasifier. The space in the furnace above the outlet end of the air inlet pipe 14 and below the feed port 2 is used as a storage bin, which has a large storage capacity and a long feeding interval, which is conducive to material level detection.

[0023] Furthermore, the steam valve port of the first three-way valve 8 is connected to a steam source and connected to a boiler to generate steam.

[0024] Furthermore, a third three-way valve 11 is connected to the top of the cyclone dust collector 7; the third three-way valve 11 is respectively connected to an air gas pipeline 12 and a water gas pipeline 13. The first three-way valve 8, the second three-way valve 9 and the third three-way valve 11 are all program-controlled valves.

[0025] Furthermore, the side wall of the furnace body 1 includes an inner interlayer 15 and an outer interlayer 16, the gas outlet 5 is connected to the outer interlayer 16, and the upward air inlet 4 is connected to the grate at the center of the ash pan 2 and introduced into the gasifier through the interlayer gap for upward suction gasification reaction.

[0026] Furthermore, a temperature sensor is provided below the air intake pipe 14. Two-core K-graded thermocouples are vertically installed at 200 mm and 600 mm below the air intake pipe 14 to measure the position and temperature of the oxide layer and the position and temperature of the carbon layer. When the temperature reaches the set value, the operating mode of each program-controlled valve is switched. This installation method can use the solid air intake pipe to provide good protection for the thermocouple sleeve.

[0027] When the utility model is in operation, the gasifier is divided into two parts, the upper part is a downdraft gasifier, and the lower part is an updraft gasifier. When the upper part is downdrafting, the air passes through the second three-way valve 9 under the action of the blower, enters the furnace body 1 from the downdraft air inlet 6, and passes through the cyclone nozzle (composed of four air inlet pipes 14) to form a rotating downward airflow. After high-temperature reaction, low-tar air and fuel gas are obtained, which enter the middle outer interlayer and exchange heat with the inner interlayer air, and are led out through the fuel gas outlet 5 and sent to the cyclone dust collector 7. Gas-solid separation is carried out in the cyclone dust collector, and the gas is discharged from the top of the dust collector and sent to the gas boiler through the third three-way valve 11. The semi-coke charcoal generated by the downdraft gasification reaction moves to the lower part of the gasifier during the fixed bed gasification operation. After the set working time of the downdraft gasification of the upper part of the gasifier is reached, or the temperature detects that the oxidation layer has reached the vicinity of the air inlet, the second three-way valve 9 is switched. Valve mouth, open the first three-way valve 8, let air enter the furnace body 1 from the upper air inlet, the air undergoes oxidation-reduction reaction with the high-temperature carbon layer to obtain tar-free air fuel gas, enters the middle outer interlayer and exchanges heat with the inner interlayer air, and then is led out from the fuel gas outlet 5 and sent to the cyclone dust collector 7 for gas-solid separation. The gas is led out from the top of the dust collector. When the temperature of the oxidation layer at the lower part of the furnace body reaches the upper limit (the fuel gas temperature reaches the set value), the first three-way valve 8 is switched to allow steam to enter the furnace body 1, and the obtained water gas is led out from the fuel gas outlet 5 and sent to the cyclone dust collector 7, where gas-solid separation is carried out, and the gas flows out from the top of the dust collector. By switching the third three-way valve, the gas passes through the water gas pipeline 13 and enters the pressure swing adsorption section to extract hydrogen. The process of decomposing water vapor to produce hydrogen is an endothermic reaction. The oxidation temperature gradually decreases, and the temperature near the gas outlet 5 decreases synchronously. When the set value is reached, the first three-way valve 8 is switched to allow air to enter the furnace body 1, and the lower part is sucked up again to heat up the air and store heat. When the temperature of the oxidation layer at the lower part of the furnace body reaches the upper limit (the gas temperature reaches the set value), the first three-way valve 8 is switched to allow steam to enter the furnace body 1 to produce water gas. Under the action of the ash pan ash discharge movement, the upper semi-coke charcoal moves downward basically (the number of reciprocating cycles can be set as a conversion condition), and the water gas heats up and stores heat and produces hydrogen. The semi-coke charcoal at the upper part of the furnace body is basically consumed. When the first three-way valve 8 completes the last air heating and heat storage procedure, the air inlet 6 is switched through the second three-way valve 9 to enter the furnace body 1, and the lower part is sucked up for gasification to produce semi-coke charcoal. The air gas is supplied to the boiler through the third three-way valve 11, and the subsequent upward absorption oxidation layer temperature heating and heat storage and hydrogen production mode are repeated, and target gases with different components are obtained in different time periods.

[0028] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0029] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A fixed bed gasifier with multi-mode switching, comprising a furnace body (1), characterized in that: The furnace body (1) is provided with a feeding port (2) at the top and an ash tray (3) at the bottom, the ash tray (3) is connected to an upper air inlet (4), and the side wall of the furnace body (1) is provided with a gas outlet (5) and a lower air inlet (6) in sequence from top to bottom; wherein the gas outlet (5) is connected to a cyclone dust collector (7); the upper air inlet (4) is connected to a blower (10) via a first three-way valve (8) and a second three-way valve (9) connected in series; and the lower air inlet (6) is connected to the second three-way valve (9).

2. The fixed bed gasifier with multi-operating mode switching according to claim 1, characterized in that: A valve port of the first three-way valve (8) is connected to a steam source.

3. The fixed bed gasifier with multi-operating mode switching according to claim 1, characterized in that: The top of the cyclone dust collector (7) is connected to a third three-way valve (11); the third three-way valve (11) is respectively connected to an air gas pipeline (12) and a water gas pipeline (13).

4. The fixed bed gasifier with multi-operating mode switching according to claim 1, characterized in that: The number of the downward air inlets (6) is at least three, and they are evenly arranged along the circumference of the side wall of the furnace body (1); an air intake pipe (14) is provided in the downward air inlet (6), and the air outlet end of the air intake pipe (14) is horizontal and has a downward section.

5. The fixed bed gasifier with multi-operating mode switching according to claim 4, characterized in that: The gas outlet end of the gas inlet pipe (14) forms an angle of 15-30° with the center line of the furnace body (1).

6. The fixed bed gasifier with multi-operating mode switching according to claim 1, characterized in that: The side wall of the furnace body (1) comprises an inner interlayer (15) and an outer interlayer (16), the gas outlet (5) is in communication with the outer interlayer (16), and the upward air inlet (4) is in communication with the inner interlayer (15).

7. The fixed bed gasifier with multi-operating mode switching according to claim 4, characterized in that: Above the air intake pipe (14) is a material storage space.

8. The fixed bed gasifier with multi-operating mode switching according to claim 4, characterized in that: A temperature sensor is also provided in the furnace body (1).

Images