Jet bubbling fluidized bed gasification furnace with double gas chambers

Abstract

The utility model relates to a jet bubbling fluidized bed gasifier with double gas chambers. The jet bubbling fluidized bed gasifier comprises a hearth, an upper gas chamber, a lower gas chamber and a grading deslagging ring pipe, the hearth comprises a pressure-bearing furnace shell and a fluidization distribution plate, a plurality of fluidization air holes are formed in the conical fluidization distribution plate, and the small-caliber end of the fluidization distribution plate is connected with the grading deslagging ring pipe; the hearth below the fluidization distribution plate is divided into the upper gas chamber and the lower gas chamber by a spacer, the top end of the spacer is connected to the fluidization distribution plate, and the bottom end of the spacer is connected to the side wall of the hearth; and the upper gas chamber and the lower gas chamber are respectively provided with a gasifying agent inlet and an ash discharge port. According to the fluidized bed gasifier provided by the invention, the lower part of the hearth is divided into the upper gas chamber and the lower gas chamber through the spacer, and other gases are introduced into one of the gas chambers, so that partial steam fluidization can be replaced, the use amount of steam and the discharge amount of wastewater are greatly reduced, the energy consumption is reduced, and the economic benefit is improved.

Description

Technical Field

[0001] The invention relates to the technical field of biomass pressurized fluidized bed, in particular to a double-chamber jet bubbling fluidized bed gasifier. Background Art

[0002] In order to cope with global warming, the world's major economies are actively promoting carbon neutrality and carbon emission reduction. Biomass energy, as the most promising renewable energy, has become the fourth largest energy source after coal, oil and natural gas by converting it into solid fuels (direct combustion), liquid fuels (methanol, ethanol, diesel, etc.) and gaseous fuels (biogas, natural gas, carbon monoxide and hydrogen, etc.) for power generation, heating, transportation fuel and industrial raw materials, and has great development potential. The promotion and application of biomass technology will be an effective technical approach to achieve the "dual carbon" goal, which can achieve zero carbon emissions and play a significant role in promoting the large-scale and efficient and clean utilization of my country's biomass resources and achieving the goal of carbon neutrality.

[0003] Gasification is an important means of converting biomass into other energy sources, and fluidized bed gasification is the most effective technology among these means. Fluidized bed gasification is different from other forms of gasification. It requires steam to be introduced into the bottom of the gasifier for fluidization. Generally, coal gasification adopts this steam fluidization method. However, biomass is different from coal. Its main characteristics are five highs and three lows: high volatile matter, high oxygen content, high reactivity, high alkali metal content, high chloride ion content, low ash content, low sulfur content, and low ash melting point. Among them, the high oxygen content will lead to more water generated after gasification. In addition, the biomass itself contains a lot of water. At this time, if water vapor is still used for fluidization, it will inevitably lead to a high water vapor content in the synthesis gas, and the steam decomposition rate will be greatly reduced, and the precious water vapor will become wastewater.

[0004] The first goal is to ensure the safety and stability of industrial production, while taking into account the economic benefits of production. In summary, there is an urgent need to use a gas to replace water vapor for fluidization. Considering that a small amount of water vapor is still needed in some areas, in order to prevent water vapor and the fluidizing gas from affecting each other, the present invention provides a double-chamber gasifier. Summary of the invention

[0005] The present invention aims at solving the problems of high water vapor content in synthesis gas, low steam decomposition rate and large amount of wastewater generated due to water vapor fluidization, in view of the high oxygen content of biomass, more water generated by gasification and the fact that biomass itself contains a large amount of water. The technical scheme adopted is: a double-chamber jet bubbling fluidized bed gasifier, comprising: a furnace, an upper gas chamber, a lower gas chamber and a graded slag discharge ring pipe; the furnace comprises: a pressure furnace shell and a fluidization distribution plate, a plurality of fluidization gas holes are arranged on the conical fluidization distribution plate, and the large-diameter end of the fluidization distribution plate is connected to the pressure furnace shell; the small-diameter end of the fluidization distribution plate is connected to the graded slag discharge ring pipe; the furnace below the fluidization distribution plate is divided into the upper gas chamber and the lower gas chamber by a spacer, the top end of the spacer is connected to the fluidization distribution plate, and the bottom end of the spacer is connected to the side wall of the furnace; the upper gas chamber and the lower gas chamber are both provided with a gasifying agent inlet and an ash discharge port.

[0006] A further improvement is that the spacer includes: a small-end flexible variable section and a large-end flexible variable section in a regular octagonal shape, the top end of the small-end flexible variable section is connected to the fluidization distribution plate, the bottom end is connected to the top end of the large-end flexible variable section, and the bottom end of the large-end flexible variable section is connected to the side wall of the furnace.

[0007] A further improvement is that a corrugated expansion joint is provided between the small-end flexible variable diameter section and the large-end flexible variable diameter section of the regular octagon.

[0008] A further improvement is that the angle between the central axis of the fluidizing gas hole and the central axis of the fluidizing distribution plate is between 45° and 105°.

[0009] A further improvement is that the cone apex angle of the conical fluidizing distribution plate is between 60° and 120°.

[0010] A further improvement is that a gas buffer plate is provided at the end of the gasifying agent inlet of the upper gas chamber, and the gas buffer plate is used to change the entry direction of the gas entering the upper gas chamber.

[0011] A further improvement is that the gasifying agent inlet of the lower gas chamber is arranged at the bottom of the lower gas chamber, and a gas distributor is provided at the end of the gasifying agent inlet of the lower gas chamber, and the gas distributor includes a hole array.

[0012] A further improvement is that a heat insulating and wear-resistant lining layer is provided on the inner wall of the furnace, the inner wall of the upper air chamber, and the inner wall of the lower air chamber.

[0013] A further improvement is that the grading slag discharge ring pipe is an annular cavity formed by a jet center tube built into the classifier cylinder, comprising: an upper classifier cylinder connected to the bottom of the fluidized distribution plate, and a lower classifier cylinder passing through a pressure-bearing lower head and connected to the upper classifier cylinder.

[0014] A further improvement is that a corrugated expansion joint is provided between the upper cylinder of the classifier and the lower cylinder of the classifier.

[0015] The beneficial effects of the present invention are:

[0016] The double-chamber jet bubbling fluidized bed gasifier provided by the present invention divides the lower part of the furnace into two upper and lower air chambers by a spacer. Other gases are introduced into one of the air chambers to replace part of the steam fluidization, thereby greatly reducing the steam usage and wastewater discharge, lowering energy consumption and improving economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a schematic structural diagram of a double-chamber jet bubbling fluidized bed gasifier of the present invention. DETAILED DESCRIPTION

[0019] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0020] In the description of the invention, it is necessary to understand that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to the specific circumstances.

[0023] The specific implementation is as follows:

[0024] like Figure 1 As shown, the present invention provides a double-chamber jet bubbling fluidized bed gasifier, comprising: a furnace 10, an upper gas chamber 20, a lower gas chamber 30, and a graded slag discharge ring pipe 40. The furnace is divided into the upper gas chamber and the lower gas chamber by a partition, and the top of the partition is connected to the fluidization distribution plate. The lower part of the furnace is divided into an upper and lower gas chamber by a partition, and other gases are introduced into one of the gas chambers to replace part of the steam fluidization, so that the steam usage and wastewater discharge are greatly reduced, the energy consumption is reduced, and the economic benefits are improved.

[0025] Specifically, the top of the spacer is connected to the middle of the fluidizing distribution plate 103, and the bottom of the spacer is connected to the side wall of the furnace. The upper air chamber 20 corresponds to the fluidizing gas holes 104 in the upper part of the fluidizing distribution plate 103, and the lower air chamber 30 corresponds to the fluidizing gas holes 104 in the lower part of the fluidizing distribution plate 103.

[0026] At the same time, the technical solution allows different fluidizing gases to be introduced into the gasifier through two air chambers, thereby greatly reducing steam usage and wastewater discharge. At the same time, compared with multiple air chambers, the space of each air chamber is large enough, so that the buffer zone against gas pressure fluctuations is large enough, and the fluidizing gas will pass through all the pores corresponding to each air chamber evenly, avoiding the problem of material backflow to the air chamber caused by uneven gas distribution.

[0027] like Figure 1 , further improved as follows, the furnace 10 includes: a pressure-bearing furnace shell 101, a heat-resistant and wear-resistant lining layer 102 is laid on the inner surface of the pressure-bearing furnace shell 101, a fluidizing distribution plate 103 is fixedly installed in the inner cavity of the pressure-bearing furnace shell 101, and the fixing method is preferably welding connection, the large end of the conical fluidizing distribution plate 103 is connected to the pressure-bearing furnace shell 101, and a certain number of fluidizing gas holes 104 are arranged on the fluidizing distribution plate 103 in an equilateral triangle arrangement.

[0028] like Figure 1, further improved as follows: the fluidized distribution plate 103 is a cone formed by rolling a steel plate, and a 30mm to 150mm thick heat-insulating and wear-resistant lining layer is provided on the surface of the cone on the furnace side, and the cone top angle θ of the conical fluidized distribution plate 103 is between 60° and 120°.

[0029] like Figure 1 , further improved as follows: the angle β between the central axis of the fluidizing gas hole 104 and the central axis of the fluidizing distribution plate 103 is between 45° and 105°.

[0030] like Figure 1 , further improved as follows: the upper gas chamber 20 includes: a heat-resistant and wear-resistant lining layer 201, 1 to 6 gasifying agent inlets 202 are opened on the pressure-bearing furnace shell 101, and a gas buffer plate 203 is provided at the end of the gasifying agent inlet 202. The gas buffer plate 203 is used to change the entry direction of the gas entering the upper gas chamber. Specifically, the gas buffer plate 203 is used to prevent the gas from blowing directly or upward along the entry direction, resulting in uneven gas pressure in different fluidizing gas holes 104 and poor fluidization effect. The gas buffer plate 203 changes the direction of the gas after entering the upper gas chamber to blow downward. After passing through the entire upper gas chamber, the gas can be blown out from all the fluidizing gas holes 104 corresponding to the upper gas chamber in a relatively balanced manner. If the above purpose is achieved, the gas buffer plate 203 can be preferably an L-shaped gas buffer plate, so that the gas enters the upper gas chamber and blows downward into the gas chamber.

[0031] The spacer includes: a regular eight-shaped small-end flexible reducing section 204 and a large-end flexible reducing section 206. The regular eight-shaped small-end flexible reducing section 204 is welded to the surface of the fluidized distribution plate 103 near the middle position, and the regular eight-shaped large-end flexible reducing section 206 is welded to the inner surface of the pressure-bearing furnace shell. Furthermore, a corrugated expansion joint 205 is connected between the small-end flexible reducing section and the large-end flexible reducing section to absorb the axial displacement of the fluidized distribution plate under hot working conditions. One to three ash discharge ports 207 are set on the pressure-bearing furnace shell and near the bottom of the large-end flexible reducing section to discharge fine ash in the upper air chamber, and a manhole 208 for upper air chamber maintenance is opened on the pressure-bearing furnace shell.

[0032] like Figure 1, further improved as follows: the lower gas chamber 30 comprises: a pressure-bearing lower end cap 301, the pressure-bearing lower end cap 301 is fixedly connected to the bottom end of the pressure-bearing furnace shell, a heat-resistant and wear-resistant lining layer 302 is laid on the inner surface of the pressure-bearing lower end cap 301, 1 to 4 gasifying agent inlets 304 are opened on the lower end cap, and a gas distributor 303 is connected to the end of the gasifying agent inlet 304 in the lower gas chamber, and a hole array is opened on the gas distributor 303, and the gas is dispersedly blown into the lower gas chamber through the gas distributor 303 to avoid direct blowing of gas into some of the fluidizing gas holes corresponding to the lower gas chamber, resulting in uneven gas blown into the fluidizing gas holes corresponding to the lower gas chamber, and poor fluidization effect. A manhole 306 for lower gas chamber maintenance and an ash discharge port 305 for discharging fine powder in the gas chamber are opened on the pressure-bearing lower end cap.

[0033] like Figure 1 , further improved as follows: the grading slag discharge ring pipe 40 is an annular cavity formed by a jet center pipe 404 built into the classifier cylinder, comprising: an upper classifier cylinder 401 connected to the bottom of the fluidized distribution plate 103, and a lower classifier cylinder 403 passing through the pressure-bearing lower head and connected to the upper classifier cylinder 401. Furthermore, a corrugated expansion joint 402 is provided between the upper classifier cylinder 401 and the lower classifier cylinder 403 to absorb the axial displacement of the fluidized distribution plate under hot working conditions.

[0034] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A double-chamber jet bubbling fluidized bed gasifier, characterized in that: include: Furnace, upper gas chamber, lower gas chamber and graded slag discharge ring pipe; The furnace comprises: a pressure furnace shell and a fluidizing distribution plate, the conical fluidizing distribution plate is provided with a plurality of fluidizing gas holes, and the large-diameter end of the fluidizing distribution plate is connected to the pressure furnace shell; The small-diameter end of the fluidized distribution plate is connected to the graded slag discharge ring pipe; The furnace below the fluidizing distribution plate is divided into an upper gas chamber and a lower gas chamber by a partition, the top end of the partition is connected to the fluidizing distribution plate, and the bottom end of the partition is connected to the side wall of the furnace, and the upper gas chamber and the lower gas chamber are both provided with a gasifying agent inlet and an ash discharge port.

2. The double-chamber jet bubbling fluidized bed gasifier according to claim 1, characterized in that: The spacer includes: a small-end flexible variable diameter section and a large-end flexible variable diameter section in a regular octagonal shape, the top end of the small-end flexible variable diameter section is connected to the fluidization distribution plate, the bottom end is connected to the top end of the large-end flexible variable diameter section, and the bottom end of the large-end flexible variable diameter section is connected to the side wall of the furnace.

3. The double-chamber jet bubbling fluidized bed gasifier according to claim 2, characterized in that: A corrugated expansion joint is arranged between the regular octagonal small-end flexible variable diameter section and the large-end flexible variable diameter section.

4. The double-chamber jet bubbling fluidized bed gasifier according to claim 1, characterized in that: The angle between the central axis of the fluidizing gas hole and the central axis of the fluidizing distribution plate is between 45° and 105°.

5. The double-chamber jet bubbling fluidized bed gasifier according to claim 1, characterized in that: The cone apex angle of the conical fluidizing distribution plate is between 60° and 120°.

6. The double-chamber jet bubbling fluidized bed gasifier according to claim 1, characterized in that: A gas buffer plate is provided at the end of the gasifying agent inlet of the upper gas chamber, and the gas buffer plate is used to change the entry direction of the gas entering the upper gas chamber.

7. The double-chamber jet bubbling fluidized bed gasifier according to claim 1, characterized in that: The gasifying agent inlet of the lower gas chamber is arranged at the bottom of the lower gas chamber, and a gas distributor is arranged at the end of the gasifying agent inlet of the lower gas chamber, and the gas distributor includes a hole array.

8. The double-chamber jet bubbling fluidized bed gasifier according to claim 1, characterized in that: The inner wall of the furnace, the inner wall of the upper air chamber, and the inner wall of the lower air chamber are all provided with a heat-insulating and wear-resistant lining layer.

9. The double-chamber jet bubbling fluidized bed gasifier according to claim 1, characterized in that: The grading slag discharge ring pipe is an annular cavity formed by a jet center tube built into the classifier cylinder, and comprises: an upper classifier cylinder connected to the bottom of the fluidized distribution plate, and a lower classifier cylinder passing through a pressure-bearing lower head and connected to the upper classifier cylinder.

10. The double-chamber jet bubbling fluidized bed gasifier according to claim 9, characterized in that: A corrugated expansion joint is arranged between the upper cylinder of the classifier and the lower cylinder of the classifier.

Images