Fluidized bed gasification furnace

Abstract

The fluidized bed gasification furnace comprises a gasification furnace body, the gasification furnace body is sequentially provided with a gas outlet, a first feed port, a second feed port, a third feed port and a slag pool from top to bottom, and the axial distance y between the second feed port and the third feed port is larger than or equal to 0; the axis of the third feeding hole is inclined towards the direction of the slag pool, and the inclination angle alpha is 0-90 degrees and does not include 0 degree; by adopting the fluidized bed gasification furnace disclosed by the utility model, liquid slag discharge can be realized, the problem that the slag discharge pipe of the fluidized bed gasification furnace is easy to block is avoided, and the operation stability of the fluidized bed gasification furnace can be integrally improved.

Description

Technical Field

[0001] The utility model relates to a fluidized bed gasification furnace. Background Art

[0002] Fluidized bed reactors are widely used in the energy and chemical industries. The fluidized bed gasification process uses solid particles as raw materials. A gas distributor is located at the bottom of the fluidized bed gasifier. During the reaction, the gasifying agent enters the bed layer evenly through the distributor. The raw material particles above the distributor are fluidized by the gasifying agent and react with the gasifying agent under certain temperature and pressure conditions to produce product gas. Compared to other gasifier reactors, fluidized bed gasifiers offer advantages such as a wide range of raw material compatibility and uniform temperature distribution within the reactor.

[0003] Fluidized bed slagging is one of the major bottlenecks limiting the development of fluidized bed gasification technology. The raw material particles in the fluidized bed are constantly fluidized, causing frequent friction and collisions between particles, resulting in the production of a large number of fine particles. These fine particles remain fluidized within the bed, but when they enter the relatively narrow and slow-flowing slagging pipes, they can easily cause blockage. Furthermore, impurities in the raw materials and large particles can also cause blockage in the slagging system.

[0004] Existing fluidized bed gasification processes that have been implemented in engineering mostly use solid slag removal, such as U-shaped valves, L-shaped valves, cone valves and other on-bed slag removal methods and under-bed slag removal methods. These slag removal methods all have the problem of particle accumulation leading to slag discharge pipe blockage. Patent application number CN202320861589.9 discloses a circulating fluidized bed slag discharge device, which adopts a dual-channel slag discharge method above and below the bed. Although it improves the stability of the fluidized bed operation, it still cannot completely avoid the blockage of the slag discharge pipe; Patent application number CN202321366071.4 discloses a hydrogen production fluidized bed bottom slag anti-blocking device, but this method has a complex structure and is difficult to apply in large-scale fluidized bed gasification furnace processes; Patent application number CN201720578244.7 discloses a fluidized bed slag discharge system, which uses airflow to accelerate the flow rate of materials in the pipeline to reduce the probability of blockage, but the materials used in fluidized bed gasification furnaces in industry are often mixed with some impurities, including iron wire, etc. The slag discharge pipeline of this method is still relatively narrow and long, and it is difficult to avoid blockage caused by these impurities.

[0005] Therefore, in practice, there is an urgent need for a fluidized bed gasifier that has stable slag discharge, is not prone to clogging, has a simple structure, and is applicable to large fluidized beds. Utility Model Content

[0006] The technical problem to be solved by the utility model is that the existing gasification furnace slag discharge is prone to blockage. A fluidized bed gasification furnace is provided. The utility model gasification furnace and the slag discharge method thereof can solve the problem of slag discharge blockage and improve the operation stability of the fluidized bed gasification furnace.

[0007] The utility model solves the above technical problems through the following technical solutions:

[0008] The utility model provides a fluidized bed gasifier, which includes a gasifier body, wherein the gasifier body is provided with a gas outlet, a first feed port, a second feed port, a third feed port and a slag pool in sequence from top to bottom;

[0009] The axial distance y between the second feed port and the third feed port is ≥ 0;

[0010] The axis of the third feed port is inclined toward the slag pool, and the inclination angle α is 0 to 90° and does not include 0°. The inclination angle is the angle between the axis of the third feed port and the horizontal plane.

[0011] In the present invention, the tilt angle α is preferably 20-70°, more preferably 30-60°, for example 45°.

[0012] In the present invention, the axial distance x between the first and second feed ports, and the axial distance z between the third feed port and the highest point of the slag pool preferably satisfy the following conditions: x ≥ z. More preferably, z is greater than or equal to 0.3 m. Even more preferably, 0.3 m ≤ z ≤ 0.2 H, where H is the axial distance from the gas outlet to the third feed port, measured in meters.

[0013] In the present invention, when y is not 0, the axial distance x between the first feed port and the second feed port, and the axial distance y between the second feed port and the third feed port preferably satisfy: x is 1 to 5 times of y, for example, 1.25 times.

[0014] In the present invention, the axial distance y between the second feed port and the third feed port, and the axial distance between the third feed port and the highest point of the liquid level in the slag pool, preferably satisfy the following conditions: 0 ≤ y ≤ 10z, for example, y is 0 or y is 1.7 times z. More preferably, z is greater than or equal to 0.3m, and even more preferably, 0.3m ≤ z ≤ 0.2H, where H is the axial distance from the gas outlet to the third feed port, measured in meters.

[0015] In the present invention, the axial distance z between the third feed port and the highest point of the liquid level of the slag pool preferably satisfies: z is greater than or equal to 0.3m. More preferably, 0.3m≤z≤0.2H, where H is the axial distance from the gas outlet to the third feed port, in meters.

[0016] In the present invention, the number of the first feed openings is at least one, and the specific number is determined according to the actual load, for example, two.

[0017] Among them, when there are at least two first feed ports, multiple second feed ports are evenly opposed to each other with the axis of the gasifier body as the center, and the projections of the first feed ports and the second feed ports on the cross section of the gasifier body are distributed at intervals. For example, when there are two first feed ports and four second feed ports, the projection of one of the first feed ports on the cross section of the gasifier body is located between the projection of the first second feed port on the cross section of the gasifier body and the projection of the second second feed port on the cross section of the gasifier body, and the projection of another first feed port on the cross section of the gasifier body is located between the projection of the third second feed port on the cross section of the gasifier body and the projection of the fourth second feed port on the cross section of the gasifier body.

[0018] In the present invention, the number of the second feed inlets is preferably at least two, and the plurality of second feed inlets are evenly opposed to each other with the axis of the gasification furnace body as the center. For example, the number of the second feed inlets is four.

[0019] In the present invention, the third feed ports are preferably at least 2, and the plurality of third feed ports are distributed in sequence along the circumference of the gasifier body and are located on the same cross-section, and the cross-section is a surface perpendicular to the axis of the gasifier body. More preferably, the third feed ports are an even number, and the plurality of third feed ports are evenly opposed to each other with the axis of the gasifier body as the center, and the inclination angles of the relative third feed ports are the same. For example, there are 4 third feed ports.

[0020] In the present invention, the fluidized bed gasifier preferably further includes a nozzle. When the axial distance y between the second feed inlet and the third feed inlet is greater than 0, or y=0, and the second feed inlet and the third feed inlet are disposed on the same cross-section of the gasifier body, the nozzle comprises a feed nozzle and a gasifying agent nozzle, wherein the feed nozzle is disposed on the second feed inlet, and the gasifying agent nozzle is disposed on the third feed inlet, with the axis of the gasifying agent nozzle outlet coinciding with the axis of the third feed inlet. In this case, the gasifying agent and the second raw material enter separately. More preferably, the second feed inlet and the third feed inlet are disposed sequentially and spaced apart on the same cross-section of the gasifier body.

[0021] When y=0, the second feed port is not set, the nozzle is set in the third feed port, the axis of the nozzle outlet coincides with the axis of the third feed port, and both the gasifying agent and the second raw material are fed through one nozzle, reducing the number of nozzles used.

[0022] In the present invention, a gasification zone, a combustion zone and a slag pool can be formed in sequence from top to bottom inside the gasification furnace body. The first feed port is arranged in the gasification zone, the second feed port is arranged in the combustion zone, and the third feed port is arranged above the slag pool and located in the combustion zone.

[0023] In the present invention, the gas outlet can be arranged on the top or side of the gasification furnace body.

[0024] In the present invention, the slag pool can be arranged at the bottom of the gasification furnace body, and a slag discharge port is provided at the bottom of the slag pool.

[0025] In the present invention, the slag pool is preferably an inverted cone structure that gradually contracts from the third feed port to the bottom of the gasification furnace body.

[0026] In a preferred embodiment of the present invention, the fluidized bed gasifier includes a gasifier body, and the gasifier body is provided with a gas outlet, a first feed port, a second feed port, a third feed port and a slag pool in sequence from top to bottom; the first feed port is 2, and the two first feed ports are evenly opposed to each other with the axis of the gasifier body as the center, the second feed port is 4, and the four second feed ports are evenly opposed to each other with the axis of the gasifier body as the center, and each second feed port is provided with a feed nozzle Nozzle, there are 4 third feed ports, and the 4 third feed ports are evenly opposed to each other with the axis of the gasifier body as the center. Each third feed port is provided with a gasifying agent nozzle, α is 45°, and the axial distance x between the first feed port and the third feed port is 1.25 times the axial distance y between the second feed port and the third feed port, and the axial distance y between the second feed port and the third feed port is 1.71 times the axial distance z between the third feed port and the highest point of the liquid level of the slag pool.

[0027] In a preferred embodiment of the present invention, the fluidized bed gasifier includes a gasifier body, and the gasifier body is provided with a gas outlet, a first feed port, a third feed port and a slag pool in sequence from top to bottom; there are two first feed ports, and the two first feed ports are evenly opposed to each other with the axis of the gasifier body as the center, and there are four third feed ports, and the third feed ports are evenly opposed to each other with the axis of the gasifier body as the center, and each of the third feed ports is provided with a gasifier nozzle, and the gasifier nozzle is used to introduce the gasifier and the second raw material, and the gasifier nozzle is a multi-channel nozzle, α is 45°, and the axial distance x between the first feed port and the third feed port is 2.14 times the axial distance z between the third feed port and the highest point of the liquid level of the slag pool.

[0028] In a preferred embodiment of the present invention, the fluidized bed gasifier includes a gasifier body, and the gasifier body is provided with a gas outlet, a first feed port, a second feed port, a third feed port and a slag pool in sequence from top to bottom; there are two first feed ports, and the two first feed ports are evenly opposed to each other with the axis of the gasifier body as the center, the second feed port and the third feed port are located on the same cross-section of the gasifier body, there are four second feed ports and four third feed ports, and all of the second feed ports and the third feed ports are evenly opposed to each other with the axis of the gasifier body as the center, each second feed port is provided with a feed nozzle, and each third feed port is provided with a gasifying agent nozzle, α is 45°, and the axial distance x between the first feed port and the third feed port is 2.14 times the axial distance z between the third feed port and the highest point of the liquid level of the slag pool.

[0029] The present invention also provides a fluidized bed gasification method, which is carried out using the aforementioned fluidized bed gasifier, and specifically includes: introducing a first raw material into the gasifier body through the first feed port, introducing a second raw material into the gasifier body through the second feed port or the third feed port, and introducing a gasifying agent into the gasifier body through the third feed port, to carry out a reaction, wherein the particle size of the first raw material is larger than that of the second raw material.

[0030] In the present invention, the second raw material is introduced into the gasifier body through the second feed port or the third feed port, which means that: when the second feed port is set, the second raw material is introduced into the gasifier body through the second feed port; when the second feed port is not set, the second raw material and the gasifying agent enter the gasifier body together from the third feed port.

[0031] In the present invention, the first raw material is solid, and the second raw material can be any of solid, liquid, and gaseous. Preferably, when the second raw material is solid and / or liquid, the particle size of the first raw material is greater than or equal to a, and the particle size of the second raw material is less than a, a=2-6 mm, more preferably, a=3 mm, and even more preferably, the particle size of the first raw material is 3-60 mm, for example, 3-15 mm.

[0032] In the present invention, preferably, the gasifying agent is a mixed gas of one or more of oxygen, a mixture of oxygen and steam, air and oxygen-enriched air.

[0033] In the present invention, the first raw material may be a mixture of one or more of coal, oil shale, biomass and solid waste, such as coal or cotton stalks.

[0034] In the present invention, the second raw material can be a mixture of one or more of coal, oil shale, biomass, solid waste, heavy oil, gasifier synthesis gas and methane, such as water-coal slurry, cotton stalks or synthesis gas.

[0035] In the present invention, the second raw material may further include the gasifying agent, and the flow rate of the gasifying agent in the second raw material preferably accounts for 10-50% of the total flow rate of the gasifying agent.

[0036] In the present invention, the flow rate of the first raw material can be 5000-7000 kg / h, for example, 5760 kg / h, 6020 kg / h or 6220 kg / h.

[0037] In the present invention, when the second raw material is solid or liquid, the flow rate of the second raw material can be 900-2000 kg / h, such as 980 kg / h, 1037 kg / h or 1168 kg / h; when the second raw material is gaseous, the flow rate of the second raw material can be 2000-3000 Nm 3 / h, for example 2024Nm 3 / h.

[0038] In the present invention, when the gasifying agent is a mixture of oxygen and steam, the flow rate of the oxygen is preferably 1000-5000 Nm 3 / h, for example 1591Nm 3 / h、2141Nm 3 / h、4523Nm 3 / h、3542Nm 3 / h or 4198Nm 3 / h; the steam flow rate is 5000-12000 kg / h, for example 5827 kg / h, 5737 kg / h, 9489 kg / h, 11352 kg / h or 10509 kg / h.

[0039] In the present invention, preferably, the diameter of the first feed port is larger than the diameter of the feed nozzle.

[0040] In the utility model, the pressure of the liquid slag discharge method of the fluidized bed gasifier is not greater than 10 MPa.

[0041] In the present invention, the temperature of the slag pool is preferably 50°C higher than the ash melting point of the material. For example, when the material is coal with an ash melting point of FT~1300°C, the temperature of the gasification zone can be 900~1100°C, the temperature of the combustion zone can be 1100~1600°C, and the temperature of the slag pool can be 1400~1500°C.

[0042] In the present invention, preferably, the maximum temperature of the combustion zone of the gasification furnace body is not lower than the temperature of the slag pool.

[0043] In the present invention, preferably, the temperature of the gasification zone of the gasification furnace body is not higher than the ash melting point of the material.

[0044] In the present invention, the fluidized bed gasification reaction method preferably includes: introducing the first raw material, the second raw material and the gasifying agent into the gasifier body through the first feed port, the second feed port and the third feed port respectively to react.

[0045] The present utility model also provides a fluidized bed liquid slag removal method, which is carried out using the aforementioned fluidized bed gasifier, and specifically includes: introducing a first raw material into the gasifier body through the first feed port, introducing a second raw material into the gasifier body through the second feed port or the third feed port, and introducing a gasifying agent into the gasifier body through the third feed port, to carry out a reaction, wherein the particle size of the first raw material is larger than that of the second raw material.

[0046] In the present invention, the second raw material is introduced into the gasifier body through the second feed port or the third feed port, which means that: when the second feed port is set, the second raw material is introduced into the gasifier body through the second feed port; when the second feed port is not set, the second raw material and the gasifying agent enter the gasifier body together from the third feed port.

[0047] In the present invention, preferably, when the second raw material is solid and / or liquid, the particle size of the first raw material is greater than or equal to a, and the particle size of the second raw material is less than a, a=2~6mm, more preferably, a=3mm, and further more preferably, the particle size of the first raw material is 3~60mm, for example 3~15mm.

[0048] In the present invention, preferably, the gasifying agent is a mixed gas of one or more of oxygen, a mixture of oxygen and steam, air and oxygen-enriched air.

[0049] In the present invention, the first raw material may be a mixture of one or more of coal, oil shale, biomass and solid waste, such as coal or cotton stalks.

[0050] In the present invention, the second raw material can be a mixture of one or more of coal, oil shale, biomass, solid waste, coal-water slurry, heavy oil and synthesis gas, such as coal-water slurry, cotton stalks or synthesis gas.

[0051] In the present invention, the second raw material may further include the gasifying agent. The gasifying agent in the second raw material preferably accounts for 10 to 50% of the total amount of the gasifying agent.

[0052] In the present invention, the second raw material may further include the aforementioned gasifying agent.

[0053] In the present invention, the flow rate of the first raw material can be 5000-7000 kg / h, for example, 5760 kg / h, 6020 kg / h or 6220 kg / h.

[0054] In the present invention, when the second raw material is solid or liquid, the flow rate of the second raw material can be 900-2000 kg / h, such as 980 kg / h, 1037 kg / h or 1168 kg / h; when the second raw material is gaseous, the flow rate of the second raw material can be 2000-3000 Nm 3 / h, for example 2024Nm 3 / h.

[0055] In the present invention, when the gasifying agent is a mixture of oxygen and steam, the flow rate of the oxygen is preferably 1000-5000 Nm 3 / h, for example 1591Nm 3 / h、2141Nm 3 / h、4523Nm 3 / h、3542Nm 3 / h or 4198Nm 3 / h; the steam flow rate is 5000-12000 kg / h, for example 5827 kg / h, 5737 kg / h, 9489 kg / h, 11352 kg / h or 10509 kg / h.

[0056] In the present invention, preferably, the diameter of the first feed port is larger than the diameter of the feed nozzle.

[0057] In the utility model, the pressure of the liquid slag discharge method of the fluidized bed gasifier is not greater than 10 MPa.

[0058] In the present invention, the temperature of the slag pool is preferably 50°C higher than the ash melting point of the material. For example, when the material is coal with an ash melting point of FT~1300°C, the temperature of the gasification zone can be 900~1100°C, the temperature of the combustion zone can be 1100~1600°C, and the temperature of the slag pool can be 1400~1500°C.

[0059] In the present invention, preferably, the maximum temperature of the combustion zone of the gasification furnace body is not lower than the temperature of the slag pool.

[0060] In the present invention, preferably, the temperature of the gasification zone of the gasification furnace body is not higher than the ash melting point of the material.

[0061] In the present invention, the fluidized bed liquid slag removal method preferably includes: introducing the first raw material, the second raw material and the gasifying agent into the gasifier body through the first feed port, the second feed port and the third feed port respectively to react.

[0062] In the above-mentioned fluidized bed gasification method and fluidized bed liquid slag discharge method of the present invention, large-particle raw materials enter the gasification zone from the first feed port and are fluidized in the gasification zone and the combustion zone, small-particle raw materials enter the combustion zone from the second feed port, and the gasifying agent is introduced from the third feed port to contact the slag pool, and is evenly dispersed under the action of the slag pool, and the liquid slag is discharged from the slag discharge port.

[0063] The positive progress effect of this utility model is:

[0064] The fluidized bed gasifier of the present invention can realize liquid slag discharge. On the one hand, it avoids the problem of easy clogging of the slag discharge pipe of the fluidized bed gasifier, and can improve the overall stability of the operation of the fluidized bed gasifier. On the other hand, the gasifier enters the slag pool and stirs the slag pool, which can effectively utilize the residual organic matter in the gasified slag produced by the fluidized bed gasifier and increase the temperature of the slag pool. At the same time, by setting the first feed port and the second feed port, large and small particles can be fed separately, wherein the small particle material is set in the combustion zone above the slag pool. After entering the combustion zone, the small particle material reacts rapidly with the gasifier entering from the third feed port, thereby increasing the temperature of the slag pool and realizing liquid slag discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is a structural schematic diagram of the fluidized bed gasifier described in Example 1 of the present utility model.

[0066] Figure 2 This is a schematic diagram of the relative horizontal positions of the first feed port, the second feed port and the third feed port of the fluidized bed gasifier described in Example 1 of the present utility model.

[0067] Figure 3 This is a schematic structural diagram of the fluidized bed gasifier described in Example 2 of the present utility model.

[0068] Description of reference numerals:

[0069] Gasifier body 1

[0070] First feed port 101

[0071] Second feed port 102

[0072] The third feed port 103

[0073] Slag pool 104

[0074] Slag discharge port 105

[0075] Gasification zone A

[0076] Combustion zone B DETAILED DESCRIPTION

[0077] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0078] Example 1

[0079] This embodiment discloses a fluidized bed gasifier, such as Figure 1 As shown, it includes a gasifier body 1, and the gasifier body 1 is provided with a gas outlet, a first feed port 101, a second feed port 102, a third feed port 103 and a slag pool 104 from top to bottom. The first feed port 101 is used to introduce the first raw material, the second feed port 102 is used to introduce the second raw material, and the third feed port 103 is used to introduce the gasifying agent. The gas outlet is arranged at the top of the gasifier body, the slag pool 104 is arranged at the bottom of the gasifier body 1, and a slag discharge port 105 is arranged at the bottom of the slag pool 104.

[0080] The axial distance x between the first feed port 101 and the second feed port 102 is 1.5 m, the axial distance y between the second feed port 102 and the third feed port 103 is 1.2 m, and the axial distance z between the third feed port 103 and the highest point of the liquid level of the slag pool 104 is 0.7 m.

[0081] There are two first feed ports 101, which are evenly opposed to each other with the axis of the gasifier body as the center; there are four second feed ports 102, which are evenly opposed to each other with the axis of the gasifier body as the center; each second feed port 102 is provided with a feed nozzle, and the projection of one first feed port 101 on the cross section of the gasifier body 1 is located between the projection of the first second feed port 102 on the cross section of the gasifier body 1 and the projection of the second second feed port 102 on the cross section of the gasifier body 1; the projection of another first feed port 101 on the cross section of the gasifier body 1 is located between the projection of the third second feed port 102 on the cross section of the gasifier body 1 and the projection of the fourth second feed port 102 on the cross section of the gasifier body 1, as shown in FIG. Figure 2 There are four third feed ports 103 , which are evenly spaced with the axis of the gasifier body as the center. Each third feed port 103 is provided with a gasifying agent nozzle, and all gasifying agent nozzles are inclined toward the slag pool 104 , with an inclination angle α of 45°.

[0082] The bed height H in the gasifier body 1 is 12 m, where H is the axial distance from the gas outlet to the third feed port 103 , and the inner diameter R of the gasifier body 1 is 2 m.

[0083] The fluidized bed gasification reaction is carried out using the fluidized bed gasifier, comprising the following steps:

[0084] The first raw material is coal with a particle size of 3 to 15 mm, the second raw material is coal with a particle size of 0 to 3 mm (excluding 3 mm) and 30% gasifying agent, wherein the mass ratio of the first raw material (large particles) to the second raw material (small particles) is 10:1, the total feed flow rate of the first raw material and the second raw material is 6842 kg / h, and the ash melting point of the coal is FT~1300°C. The gasifying agent is a mixture of oxygen and steam, wherein the total oxygen flow rate is 3831 Nm 3 / h, the total steam flow rate is 10924kg / h. The operating pressure of the gasifier is 0.1MPaG.

[0085] Among them, the first raw material is transported into the gasifier body 1 through the first feed port 101 by a screw feeder; the coal in the second raw material is transported into the gasifier body 1 through the feed nozzle of the second feed port 102 by the CO2 airflow, and the pulverized coal nozzle flow rate in the feed nozzle is 5m / s. 30% of the gasifier enters the gasifier body 1 together with the second raw material, the oxygen nozzle flow rate in the gasifier is 50m / s, the steam nozzle flow rate is 2m / s, and the remaining gasifier enters the furnace through the gasifier nozzle.

[0086] The fluidized bed gasifier is divided into a gasification zone A, a combustion zone B, and a slag pool 104 from top to bottom. Each zone is provided with a temperature measuring point for measuring its own temperature.

[0087] According to measurements, the temperature of the gasification zone of this embodiment is 900-1100°C, the temperature of the combustion zone is 1100-1600°C, and the temperature of the slag pool is 1400-1500°C. The slag pool temperature is more than 50°C higher than the melting point of the coal ash, which can ensure smooth slag discharge.

[0088] Example 2

[0089] This embodiment discloses a fluidized bed gasifier, such as Figure 3 As shown, it includes a gasifier body 1, and the gasifier body 1 is provided with a gas outlet, a first feed port 101, a third feed port 103 and a slag pool 104 from top to bottom. The first feed port 101 is used to introduce the first raw material, and the third feed port 103 is used to introduce the second raw material and the gasifying agent. The gas outlet is arranged at the top of the gasifier body, and the slag pool 104 is arranged at the bottom of the gasifier body 1. A slag discharge port 105 is provided at the bottom of the slag pool 104.

[0090] The axial distance x between the first feed port 101 and the third feed port 103 is 1.5 m, and the axial distance z between the third feed port 103 and the highest point of the liquid level of the slag pool 104 is 0.7 m.

[0091] There are two first feed ports 101, which are evenly opposed to each other with the axis of the gasifier body 1 as the center. There are four third feed ports 103, which are evenly opposed to each other with the axis of the gasifier body as the center. Each third feed port 103 is provided with a gasifier nozzle, and the gasifier nozzle is a multi-channel nozzle. All gasifier nozzles are inclined toward the slag pool 104, and the inclination angle α is 45°. The distribution of the projections of the first feed port 101 and the third feed port 103 on the cross section of the gasifier body 1 is the same as the distribution of the projections of the first feed port 101 and the second feed port 102 on the cross section of the gasifier body 1 in Example 1.

[0092] The bed height H in the gasifier body 1 is 12 m, where H is the axial distance from the gas outlet to the third feed port 103 , and the inner diameter R of the gasifier body 1 is 2 m.

[0093] The fluidized bed gasification reaction is carried out using the fluidized bed gasifier, comprising the following steps:

[0094] The first raw material is coal with a particle size of 3 to 15 mm, and the second raw material is coal with a particle size of 0 to 3 mm (excluding 3 mm). The mass ratio of the first raw material (large particles) to the second raw material (small particles) is 10:1. The total feed flow rate of the coal is 6842 kg / h, and the ash melting point of the coal is FT~1300°C. The gasifying agent is a mixture of oxygen and steam, and the oxygen flow rate is 3831 Nm 3 / h, steam flow rate is 10924kg / h. The operating pressure of the gasifier is 0.1MPaG.

[0095] The first raw material is transported into the gasifier body 1 through the first feed port 101 by a screw feeder; the second raw material is transported into the gasifier body 1 through the gasifier nozzle by the CO2 airflow, and the gasifier also enters the gasifier body 1 through the gasifier nozzle. The flow rate of the pulverized coal nozzle in the gasifier nozzle is 5m / s, the flow rate of the oxygen nozzle is 50m / s, and the flow rate of the steam nozzle is 2m / s.

[0096] The fluidized bed gasifier is divided into a gasification zone A, a combustion zone B, and a slag pool 104 from top to bottom. Each zone is provided with a temperature measuring point for measuring its respective temperature. According to measurements, the temperature of the gasification zone of this embodiment is 900-1100°C, the temperature of the combustion zone is 1100-1600°C, and the temperature of the slag pool is 1400-1500°C. The temperature of the slag pool is more than 50°C higher than the melting point of the coal ash. This embodiment can ensure smooth slag discharge.

[0097] Examples 3 to 7

[0098] Except for some process parameters that are different from those in Example 1 (see Table 2 for details), the remaining equipment parameters and reaction conditions in Examples 3 to 7 are the same as those in Example 1. The composition of the synthesis gas used as the second raw material in Examples 5 and 7 is shown in Table 3.

[0099] Table 2 Fluidized bed gasifier process parameters of Examples 3 to 7

[0100]

[0101]

[0102] Table 3 Composition of the synthesis gas used as the second raw material in Examples 5 and 7

[0103]

[0104] The results show that the experimental effects of Examples 3 to 7 are similar to those of Example 1, and the slag pool temperature is more than 50° C. higher than the ash melting point of the material, which can ensure smooth slag discharge.

[0105] Comparative Example 1

[0106] The only difference between this comparative example and Example 1 is that the gasifying agent nozzle in this comparative example is tilted upward and the tilt angle (i.e., the angle between the gasifying agent nozzle outlet axis and the horizontal plane) is 30°. The remaining equipment parameters and reaction conditions are the same as those in Example 1.

[0107] The results showed that the slag pool temperature of the fluidized bed gasifier was 1200-1300°C, which was too low to operate normally.

Claims

1. A fluidized bed gasifier, characterized in that: The gasifier comprises a gasifier body, wherein the gasifier body is provided with a gas outlet, a first feed port, a second feed port, a third feed port and a slag pool in sequence from top to bottom; The axial distance y between the second feed port and the third feed port is ≥ 0; The axis of the third feed port is inclined toward the slag pool, and the inclination angle α is 0 to 90° and does not include 0°. The inclination angle is the angle between the axis of the third feed port and the horizontal plane.

2. The fluidized bed gasifier according to claim 1, wherein: The inclination angle α is 20 to 70 degrees.

3. The fluidized bed gasifier according to claim 2, wherein: The inclination angle α is 30 to 60 degrees.

4. The fluidized bed gasifier according to claim 1, wherein: When y is not 0, the axial distance x between the first feed port and the second feed port, and the axial distance y between the second feed port and the third feed port satisfy: x is 1 to 5 times y.

5. The fluidized bed gasifier according to claim 1, wherein: The axial distance x between the first feed port and the second feed port, and the axial distance z between the third feed port and the highest point of the liquid surface of the slag pool satisfy the following conditions: x ≥ z, where z is greater than or equal to 0.3 m; And / or, the axial distance y between the second feed port and the third feed port, and the axial distance z between the third feed port and the highest point of the liquid level of the slag pool satisfy: 0≤y≤10z.

6. The fluidized bed gasifier according to claim 5, characterized in that: 0.3m≤z≤0.2H, H is the axial distance from the gas outlet to the third feed port, in m.

7. The fluidized bed gasifier according to claim 1, wherein: The fluidized bed gasifier further includes a nozzle; When the axial distance y between the second feed inlet and the third feed inlet is greater than 0, or y is equal to 0 and the second feed inlet and the third feed inlet are arranged on the same cross section of the gasifier body, the nozzle includes a feed nozzle and a gasifying agent nozzle, the feed nozzle is arranged on the second feed inlet, the gasifying agent nozzle is arranged on the third feed inlet, and the axis of the outlet of the gasifying agent nozzle coincides with the axis of the third feed inlet; When y=0, the second feed port is not provided, the nozzle is provided in the third feed port, and the axis of the nozzle outlet coincides with the axis of the third feed port.

8. The fluidized bed gasifier according to claim 1, wherein: The fluidized bed gasifier satisfies one or more of the following conditions ① to ③: ① There is at least one first feed inlet. When there are at least two first feed inlets, the plurality of first feed inlets are evenly opposed to each other with the axis of the gasifier body as the center, and the projections of the first feed inlet and the second feed inlet on the cross section of the gasifier body are spaced apart. ② There are at least two second feed inlets, and the plurality of second feed inlets are evenly opposed to each other with the axis of the gasifier body as the center; ③ There are at least two third feed ports, and the plurality of third feed ports are distributed in sequence along the circumference of the gasifier body and are located on the same cross section, where the cross section is a surface perpendicular to the axis of the gasifier body.

9. The fluidized bed gasifier according to claim 1, wherein: The fluidized bed gasifier satisfies one or more of the following conditions ① to ③: ① The gas outlet is arranged on the top or side of the gasifier body; ② The slag pool is arranged at the bottom of the gasification furnace body, and a slag discharge port is provided at the bottom of the slag pool; ③ The slag pool is an inverted cone structure that gradually shrinks from the third feed port to the bottom of the gasification furnace body.

10. The fluidized bed gasifier according to claim 1, wherein: The fluidized bed gasifier includes a gasifier body, on which a gas outlet, a first feed port, a second feed port, a third feed port, and a slag pool are sequentially provided from top to bottom; there are two first feed ports, which are evenly opposed to each other with the axis of the gasifier body as the center, there are four second feed ports, which are evenly opposed to each other with the axis of the gasifier body as the center, each second feed port is provided with a feed nozzle, there are four third feed ports, which are evenly opposed to each other with the axis of the gasifier body as the center, each third feed port is provided with a gasifying agent nozzle, α is 45°, an axial distance x between the first feed port and the third feed port is 1.25 times the axial distance y between the second feed port and the third feed port, and an axial distance y between the second feed port and the third feed port is 1.71 times the axial distance z between the third feed port and the highest point of the liquid surface of the slag pool; Alternatively, the fluidized bed gasifier includes a gasifier body, on which a gas outlet, a first feed port, a third feed port, and a slag pool are sequentially provided from top to bottom; there are two first feed ports, which are evenly opposed to each other with the axis of the gasifier body as the center, there are four third feed ports, which are evenly opposed to each other with the axis of the gasifier body as the center, each third feed port is provided with a gasifying agent nozzle, the gasifying agent nozzle is used to introduce a gasifying agent and a second raw material, the gasifying agent nozzle is a multi-channel nozzle, α is 45°, and the axial distance x between the first feed port and the third feed port is 2.14 times the axial distance z between the third feed port and the highest point of the liquid level of the slag pool; Alternatively, the fluidized bed gasifier includes a gasifier body, and the gasifier body is provided with a gas outlet, a first feed port, a second feed port, a third feed port and a slag pool in sequence from top to bottom; there are two first feed ports, and the two first feed ports are evenly opposed to each other with the axis of the gasifier body as the center, the second feed port and the third feed port are located on the same cross-section of the gasifier body, there are four second feed ports and four third feed ports, and all of the second feed ports and the third feed ports are evenly opposed to each other with the axis of the gasifier body as the center, each second feed port is provided with a feed nozzle, and each third feed port is provided with a gasifying agent nozzle, α is 45°, and the axial distance x between the first feed port and the third feed port is 2.14 times the axial distance z between the third feed port and the highest point of the liquid level of the slag pool.

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