A gasification furnace

Abstract

The present invention discloses a gasifier, characterized in that it comprises a reaction section and a quenching section, wherein the reaction section comprises a horizontally arranged front reaction section and a vertically arranged rear reaction section, wherein the front reaction section, the rear reaction section and the quenching section are sequentially connected; wherein an inlet for gasifying agent and solid materials to enter is provided at one end of the front reaction section away from the rear reaction section. The present invention has the advantages of good raw material particle size adaptability, high carbon conversion rate, etc.

Description

Technical Field

[0001] The present invention relates to the field of gasification technology, and more particularly to a gasification furnace. Background Art

[0002] Gasifier is a key equipment for chemically converting solid raw materials into gaseous products. For example, coal gasifier converts solid coal into synthesis gas through combustion and gasification reaction, which is a key step for further converting synthesis gas into ammonia, methanol, natural gas and oil products. Gasifiers are generally divided into fixed bed gasifiers, fluidized bed gasifiers and entrained flow gasifiers. Since the synthesis reaction in the subsequent section of the gasifier is generally carried out under high pressure, and the entrained flow gasifier has the characteristics of high reaction pressure, it is more energy-efficient to use an entrained flow gasifier as the pre-stage of high-pressure synthesis. In addition, the entrained flow gasifier also has the advantage of large production capacity, which can reduce the investment in large-scale chemical projects, and is therefore the most widely used in modern large-scale chemical projects.

[0003] The entrained flow gasifier has certain restrictions on the particle size of raw materials and can only process powdered solid raw materials below 1mm. For granular or block raw materials, they need to be crushed and ground in advance, which increases energy consumption. Moreover, for some raw materials that cannot be fed as powdered solids, the entrained flow gasifier technology cannot be used. Summary of the invention

[0004] The object of the present invention is to provide a gasifier to solve the problem that the existing entrained flow gasifier has poor adaptability to raw material particle size and cannot use granular raw materials.

[0005] In order to achieve the purpose and other advantages of the present invention, a gasifier is provided, including a reaction section and a quenching section, wherein the reaction section includes a horizontally arranged front reaction section and a vertically arranged rear reaction section, and the front reaction section, the rear reaction section and the quenching section are connected in sequence; wherein an inlet for gasifying agent and solid material is provided at one end of the front reaction section away from the rear reaction section, and the temperature of the front reaction section is not less than 300°C.

[0006] Preferably, in the gasifier, the number of the front reaction sections is greater than or equal to 2, and the plurality of front reaction sections are evenly distributed around the central axis of the rear reaction section.

[0007] Preferably, in the gasifier, a screw conveying mechanism or an intermittent conveying mechanism is provided in the front reaction section, and the reaction temperature of the front reaction section does not exceed 800°C.

[0008] Preferably, a burner installation opening is provided at the top of one end of the front reaction section connected to the rear reaction section, and a burner is connected to the burner installation opening.

[0009] Preferably, in the gasifier, the inlet includes a gasifying agent inlet and a solid material inlet.

[0010] Preferably, in the gasifier, the feed to the solid material inlet is solid material with a particle size of 1 mm to 50 mm; the feed to the burner is solid material and / or gasifying agent with a particle size less than 1 mm, and the feed to the burner directly enters the rear reaction section downward through the end of the front reaction section connected to the rear reaction section.

[0011] Preferably, the gasifier further comprises an outer shell, and the reaction section and the quenching section are both located inside the outer shell.

[0012] Preferably, in the gasifier, the reaction section is further provided with a lining, and the lining is a heat-insulating refractory material, or a heat-insulating device composed of a water-cooling pipe, or a heat-insulating device composed partly of a heat-insulating refractory material and partly of a water-cooling pipe.

[0013] Preferably, the gasifier further comprises a heat recovery section, which is arranged between the post-reaction section and the quenching section, and the heat recovery section comprises a heat exchanger, a heat absorbing medium inlet and a heat absorbing medium outlet.

[0014] Preferably, in the gasifier, the quenching section is provided with a product gas outlet, an ash outlet, a quenching water inlet and a quenching water outlet.

[0015] The present invention has at least the following beneficial effects:

[0016] First, the raw material particle size adaptability is good. For solid powders below 1 mm, they directly enter the post-reaction section of the gasifier from the burner. The post-reaction section is a reactor in the form of an entrained bed, and the gasification reaction rate is high. For solid materials of 1 mm to 50 mm, they first enter the front reaction section of the gasifier, and the solid materials are carried by the gas in a pneumatic conveying manner without deposition, or are transported to the post-reaction section by a screw conveying mechanism or an intermittent conveying mechanism. As the solid materials are rapidly heated and crushed and decomposed, the solid materials continuously collide and crush during the pneumatic conveying process, and the ash layer on the surface of the solid materials falls off, the particle size of the solid materials is continuously reduced, the reaction rate is increased, and the solid materials are converted into powders below 1 mm before entering the post-reaction section. The gasifier of the present invention can gasify raw materials of different particle sizes at the same time, reducing the requirements for the size of the raw materials, thereby reducing the cost of raw material pretreatment for crushing and grinding. In addition, the gasifier of the present invention can process certain raw materials that cannot be fed in powdered solid form.

[0017] Second, the production capacity is large. By increasing the number of pre-reaction stages, the feed amount of solid materials can be increased, thereby increasing the processing capacity of the gasifier, and the gasifier has a large production capacity.

[0018] Third, the carbon conversion rate is high. By controlling the gas flow rate in the front reaction section, or controlling the speed of the screw conveying mechanism, or the frequency of the intermittent conveying mechanism, the residence time of the solid material in the front reaction section can be controlled, thereby ensuring that the carbon element in the solid material can fully react and be converted into product gas.

[0019] Fourth, the reaction pressure is high. The shell of the gasifier can be made of pressure-bearing steel shell. Due to the use of thermal insulation lining structure, the shell does not need to withstand high temperature to withstand pressure, so the operating pressure of the gasifier can reach 8.7MPag, which is particularly suitable for the chemical field that requires high-pressure synthesis.

[0020] Fifth, high energy utilization rate. By setting up a heat recovery section, the sensible heat of gaseous products and ash is recovered and the heat absorbing medium is heated, which can improve the energy utilization rate of the gasifier. If the heat absorbing medium is boiler water, the generated hot water or steam can be used for heating or power generation.

[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the overall structure of a gasifier according to an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 One of the structural diagrams in the middle AA direction;

[0024] Figure 3 yes Figure 1 Another structural diagram of the middle AA direction;

[0025] Figure 4 yes Figure 1 Another structural diagram of the middle AA direction;

[0026] Figure 5 is a schematic diagram of the overall structure of a gasifier according to another embodiment of the present invention;

[0027] Figure 6 is a schematic diagram of the overall structure of a gasifier according to another embodiment of the present invention;

[0028] Figure 7 It is a schematic diagram of the overall structure of a gasifier in the conveying stroke of an intermittent conveying mechanism according to another embodiment of the present invention;

[0029] Figure 8 It is a schematic diagram of the overall structure of a gasifier during the resetting stroke of an intermittent conveying mechanism according to another embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with embodiments and drawings so that those skilled in the art can implement the invention with reference to the description.

[0031] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0032] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] Embodiment 1:

[0034] like Figure 1 , Figure 2 As shown, this embodiment provides a gasifier, including a reaction section 11 and a quenching section 13, the reaction section 11 includes a horizontally arranged front reaction section 111 and a vertically arranged rear reaction section 112, the front reaction section 111, the rear reaction section 112 and the quenching section 13 are connected and communicated in sequence; wherein, the front reaction section 111 is a hollow structure, and an end of the front reaction section 111 away from the rear reaction section 112 is provided with an inlet for gasifying agent and solid material to enter, and the inlet can be set to 1 or 2. When it is set to 1, the gasifying agent and the solid material both enter the front reaction section 111 from the inlet. Preferably, the inlet is set to two, namely a gasifying agent inlet 113 and a solid material inlet 114, the gasifying agent enters the front reaction section 111 from the gasifying agent inlet 113, and the solid material enters the front reaction section 111 from the solid material inlet 114, and the rear reaction section 112 is a fluidized bed reactor.

[0035] Furthermore, the reaction temperature of the front reaction section is not less than 300° C., and the length of the front reaction section is preferably such that the particle size of the solid material after exiting the front reaction section becomes less than 1 mm, which can be specifically determined according to the type of solid material.

[0036] Furthermore, the number of the front reaction sections 111 is 2, and the two front reaction sections 111 are symmetrically arranged around the central axis of the rear reaction section 112 .

[0037] Furthermore, the feed of the solid material inlet 114 is solid material with a particle size of 1 mm to 50 mm.

[0038] Furthermore, the gasifier further comprises an outer shell 10 , which is a pressure-bearing steel shell, and the reaction section 11 and the quenching section 13 are both located inside the outer shell 10 .

[0039] Furthermore, the reaction section 11 is also provided with a lining 115, and the lining 115 is a heat-insulating refractory material, or a heat-insulating device composed of a water-cooling pipe, or a heat-insulating device composed of part of a heat-insulating refractory material and part of a water-cooling pipe.

[0040] Furthermore, the gasifier further comprises a heat recovery section 12, which is disposed between the post-reaction section 112 and the quenching section 13, and the heat recovery section 12 comprises a heat exchanger 121, a heat absorbing medium inlet 122 connected to the inlet of the heat exchanger 121, and a heat absorbing medium outlet 123 connected to the outlet of the heat exchanger 121.

[0041] Furthermore, the quenching section 13 is provided with a product gas outlet 131, an ash outlet 132, a quenching water inlet 133 and a quenching water outlet 134, wherein the product gas outlet 131 is arranged at the upper part of the quenching section 13, the ash outlet 132 is arranged at the bottom of the quenching section 13, and the quenching water inlet 133 and the quenching water outlet 134 are both arranged on the side wall of the quenching section 13.

[0042] Working principle:

[0043] 1. The gasifier and the carbon-containing solid material of 1 mm to 50 mm enter the front reaction section 111 of the gasifier through a common inlet, or the gasifier enters the front reaction section 111 of the gasifier through the gasifier inlet 113 and the carbon-containing solid material of 1 mm to 50 mm enters the front reaction section 111 of the gasifier through the solid material inlet 114. In the front reaction section 111, the solid material is carried by the gas in a pneumatic conveying manner and does not deposit. During the conveying process, the solid material undergoes combustion and gasification reaction with oxygen, water vapor, carbon dioxide, etc. in the gasifier at high temperature to generate gaseous products and ash containing CO and H2. As the solid material is rapidly heated and broken and decomposed, the solid materials continuously collide and break during the pneumatic conveying process, and the ash layer on the surface of the solid material falls off, the particle size of the solid material is continuously reduced, which increases the reaction rate. The gas-solid mixture in the two front reaction sections 111 converges at their connection and enters the rear reaction section 112 downward to continue the gasification reaction, so that the unreacted carbon in the solid material is further reacted and converted into gaseous products.

[0044] 2. The lining in the reaction section acts as a heat insulator, maintaining a high temperature environment in the reaction chamber and reducing the heat dissipation loss of the gasification reaction. If the lining is made of insulating refractory materials, the heat flux density and heat dissipation loss are small due to the low thermal conductivity of the insulating refractory materials themselves. If the lining is a heat-insulating device composed of water-cooled pipes, a solid and liquid ash layer is formed on the water-cooled pipes, and the slag-resisting slag effect can prevent the water-cooled pipes from being corroded by the slag, and the ash layer has a low thermal conductivity, which can reduce the heat absorption loss of the water-cooled pipes. At the same time, the outer shell of the gasifier can be made of a pressure-bearing steel shell. Due to the use of an insulating lining structure, the outer shell does not have to withstand high temperatures to withstand pressure, so the operating pressure of the gasifier can reach 8.7MPag.

[0045] 3. After the gaseous products and ash flow out from the post-reaction section 112, they are cooled in the heat recovery section (12) and the heat absorbing medium is heated to recover the sensible heat of the products, and then enter the quenching section (13). In the quenching section (13), the high-temperature gaseous products and ash are cooled by quenching water, and the high-temperature ash is rapidly solidified to form glass particles, sinking to the bottom of the quenching section and discharged from the ash outlet 132. The gaseous products are washed with cooling water to separate the ash, and flow upward to be discharged from the product gas outlet 131.

[0046] In this embodiment, by setting the reaction section as a front reaction section and a rear reaction section to simultaneously gasify solid materials of different particle sizes, the requirements of the gasifier on the size of solid materials are reduced; by setting multiple front reaction sections to increase the feed amount of solid materials, the processing capacity of the gasifier is increased, and the production capacity of the gasifier is improved; by controlling the gas flow rate in the front reaction section to control the residence time of the solid material in the front reaction section, it is ensured that the carbon element in the solid material can be fully reacted and converted into product gas, thereby improving the carbon conversion rate of the solid material.

[0047] Embodiment 2:

[0048] like Figure 1 , Figure 3 As shown, this embodiment provides a gasifier, which is different from Example 1 in that the two front reaction sections 111 are arranged along the tangent direction of the cross section of the rear reaction section 112. In this case, the rear reaction section 112 forms a cyclonic flow field, which strengthens gas-solid mixing and chemical reaction. In addition, the solid material entering the rear reaction section 112 moves toward the wall under the action of centrifugal force, and is more likely to adhere to the wall to form liquid slag and flow downward. Compared with the reaction of the solid material in the gas space of the rear reaction section 112, the residence time of the solid material is increased, which is conducive to the improvement of the carbon conversion rate.

[0049] Embodiment 3:

[0050] like Figure 1 and Figure 4As shown, this embodiment provides a gasifier, which is different from Embodiment 1 in that three front reaction sections 111 are provided, and the three front reaction sections 111 are evenly distributed along the central axis of the rear reaction section 112. Compared with Embodiment 1, the production capacity of the gasifier in this embodiment is increased by 50%.

[0051] Embodiment 4:

[0052] like Figure 5 As shown, a burner installation port 116 is provided at the top of one end connected to the plurality of front reaction sections 111, and a burner 14 is connected to the burner installation port 116. The feed of the burner 14 is a solid material and / or a gasifying agent with a particle size less than 1 mm, and the feed of the burner 14 directly enters the rear reaction section 112 downward through one end connected to the rear reaction section 112 of the front reaction section 111. In the rear reaction section 112, the solid material undergoes combustion and gasification reaction with oxygen, water vapor, carbon dioxide, etc. in the gasifying agent at high temperature to generate gaseous products containing CO and H2 and ash.

[0053] In this embodiment, a burner is added to further improve the raw material particle size adaptability of the gasifier, so that solid powder below 1 mm and solid materials above 1 mm are fed through the burner and the solid material inlet respectively.

[0054] Embodiment 5:

[0055] like Figure 6 As shown, a screw conveying mechanism 117 is provided in the front reaction section 111, and the solid material is continuously conveyed to the rear reaction section 112 by the screw conveying mechanism 117. In order to ensure the service life of the screw conveying mechanism, the reaction temperature of the front reaction section 111 does not exceed 800° C. By controlling the rotation speed of the screw conveying mechanism, the residence time of the solid material in the front reaction section can be controlled, so that the solid material is fully crushed and decomposed in the front reaction section, and continuously collides and crushes and decomposes during the conveying process, and finally the solid material is converted into powder below 1 mm before entering the rear reaction section, thereby ensuring that the carbon element in the solid material can fully react and be converted into product gas, thereby improving the carbon conversion rate of the solid material.

[0056] Embodiment 6:

[0057] like Figure 7 and Figure 8An intermittent conveying mechanism 118 is provided in the front reaction section 111, and the solid material is intermittently conveyed to the rear reaction section 112 by the intermittent conveying mechanism 118. In order to ensure the service life of the intermittent conveying mechanism, the reaction temperature of the front reaction section (111) does not exceed 800° C. By controlling the frequency of the intermittent conveying mechanism, the residence time of the solid material in the front reaction section can be controlled, so that the solid material is fully crushed and decomposed in the front reaction section, and the solid material is continuously collided and crushed and decomposed during the conveying process, and finally the solid material is converted into powder below 1 mm before entering the rear reaction section, thereby ensuring that the carbon element in the solid material can be fully reacted and converted into product gas, thereby improving the carbon conversion rate of the solid material.

[0058] Application examples:

[0059] When corn stalks are crushed to less than 1 mm, their bulk density is only about 150 kg / m 3 It is difficult to achieve dense phase transportation. Since the amount of gas transported is too large, it is not practical to use it directly in an entrained flow gasifier.

[0060] The gasifier of Example 1 is used to process corn stalks into 10 mm to 50 mm pellets, which enter the gasifier from the solid material inlet 114 and first enter the front reaction section 111 of the gasifier. The solid material is carried by the gas in a pneumatic conveying manner and does not deposit. The volatile content of corn stalks is about 75%. As the solid material is rapidly heated and precipitates a large amount of volatile matter, the particles are broken and decomposed. In addition, the solid materials collide and break continuously during the pneumatic conveying process, and the ash layer on the surface of the solid materials falls off, which continuously reduces the particle size of the solid materials and increases the reaction rate. After the solid materials are converted into powders below 1 mm, they enter the rear reaction section 112 to continue the reaction. Therefore, the present invention can realize the entrained bed gasification of pellets of 10 mm to 50 mm.

[0061] The number of equipment and processing scales described herein are intended to simplify the description of the invention. Applications, modifications and variations of the gasifier of the present invention will be apparent to those skilled in the art.

[0062] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A gasifier, characterized in that: The invention comprises a reaction section and a quenching section, wherein the reaction section comprises a horizontally arranged front reaction section and a vertically arranged rear reaction section, wherein the front reaction section, the rear reaction section and the quenching section are sequentially connected; wherein a gasifying agent inlet and a solid material inlet for gasifying agent and solid material are provided at one end of the front reaction section away from the rear reaction section, a screw conveying mechanism or an intermittent conveying mechanism is provided in the front reaction section, the temperature of the front reaction section is 300°C to 800°C, and the length of the front reaction section is such that the particle size of the solid material after exiting the front reaction section is reduced to 0.1%. It is preferably converted to less than 1mm; a burner installation port is provided at the top of one end of the front reaction section connected to the rear reaction section, and a burner is connected to the burner installation port; the feed of the solid material inlet is a solid material with a particle size of 50mm, the feed of the gasifying agent inlet is a gasifying agent, the feed of the burner is a solid material with a particle size of less than 1mm and a gasifying agent, and the feed of the burner directly enters the rear reaction section downward through one end of the front reaction section connected to the rear reaction section, and the gasifying agent includes oxygen, water vapor and carbon dioxide; The number of the front reaction sections is greater than or equal to 2, and the plurality of front reaction sections are evenly distributed around the central axis of the rear reaction section.

2. The gasifier according to claim 1, characterized in that: It also includes a shell, and the reaction section and the quenching section are both located inside the shell.

3. The gasifier according to claim 1, characterized in that: The reaction section is also provided with a lining, which is a heat-insulating refractory material, or a heat-insulating device composed of a water-cooling pipe, or a heat-insulating device composed partly of a heat-insulating refractory material and partly of a water-cooling pipe.

4. The gasifier according to claim 1, characterized in that: It also includes a heat recovery section, which is arranged between the post-reaction section and the quenching section. The heat recovery section includes a heat exchanger, a heat absorbing medium inlet and a heat absorbing medium outlet.

5. The gasifier according to claim 1, characterized in that: The quenching section is provided with a product gas outlet, an ash outlet, a quenching water inlet and a quenching water outlet.

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