A moving bed reactor

Abstract

The present invention discloses a moving bed reactor, wherein a gas inlet and a solid reactant outlet are arranged at the lower part of the moving bed reactor; a gas outlet and a solid reactant inlet are arranged at the upper part of the moving bed reactor; a horizontally rotatable turntable is arranged inside the moving bed reactor, and the turntable includes a sealed partition, a breathable partition and a distribution port; wherein the sealed partition blocks the solid reactant and the gas from passing through; the breathable partition blocks the solid reactant from passing through, but allows the gas to pass through; and the distribution port allows the solid reactant to pass through. This embodiment divides the reactor into a plurality of stepped areas by means of a turntable, realizes multi-stage series adsorption, ensures the reaction effect, and at the same time maximizes the saturated working sulfur capacity of the activated coke at the saturated coke outlet, and prolongs the regeneration cycle of the activated coke.

Description

Technical Field

[0001] The present invention belongs to the field of flue gas desulfurization equipment, and specifically relates to a moving bed reactor. Background Art

[0002] At present, the main technologies in the field of flue gas desulfurization treatment include limestone / lime-gypsum wet desulfurization technology, magnesium wet desulfurization technology, double alkali wet desulfurization technology, circulating fluidized bed semi-dry desulfurization technology, and baking soda dry desulfurization technology. In recent years, activated coke desulfurization technology has been widely used in the field of steel flue gas treatment. The desulfurization principle of activated coke is somewhat different from the above desulfurization principle. The raw material of activated coke is coal. Its desulfurization principle mainly relies on the adsorption of SO2 by the developed pores of coke itself, and the adsorption process rate is relatively slow.

[0003] The process used for activated coke desulfurization is usually a cross-current moving bed or a countercurrent moving bed. The system equipment is large in size, the investment is high, and the initial coke loading is large.

[0004] In industrial applications, activated coke flue gas purification reactors can be divided into fixed bed, moving bed, fluidized bed and other types according to the reactor bed type.

[0005] The fixed bed reactor is the reactor with the simplest structure. Its basic principle is to pile up the activated coke in the reaction tower to form a granular bed with high porosity and dust absorption rate. During the flue gas purification process, the coke layer remains stationary and the flue gas passes through the activated coke layer from bottom to top. The activated coke undergoes an adsorption reaction, thereby achieving adsorption purification of the flue gas. The fixed bed reactor has a simple structure. During the flue gas purification process, the effective residence time of the flue gas in the bed can be strictly controlled, which is beneficial to improving the removal efficiency of the system. However, the adsorption capacity of the activated coke loaded in the fixed bed reactor is limited. Once the adsorption saturation is reached, it will no longer adsorb. Therefore, during the application of the reactor, the adsorption capacity of the bed will decrease as the adsorption time increases. When the flue gas volume exceeds the adsorption upper limit of the activated coke, the purification effect of the system is greatly reduced. In addition, when the processing volume is large, in order to ensure the removal efficiency, the equipment size needs to be enlarged. Most of them adopt the form of multi-tower parallel connection, which increases the site cost. Therefore, fixed bed reactors are generally used in single desulfurization processes.

[0006] Fluidized bed reactors have the advantages of large gas-solid flux, stable material flow in the reactor, high continuity and automation, uniform bed temperature distribution, and relatively ideal interphase mass and heat transfer efficiency. They are widely used in gas purification fields such as pulverized coal boiler flue gas purification, waste incineration waste gas, and electrolytic waste gas treatment. However, due to the characteristics of the fluidized bed, a large amount of activated coke powder will be entrained by the flue gas during the gas-solid two-phase flow process, which needs to be separated and recycled back to the bed. The requirements for gas-solid separation at the back end of the reactor are very high, which has become the key to restricting the industrialization of powdered activated coke fluidized bed flue gas purification.

[0007] Compared with fixed bed reactors, moving bed reactors have better continuity and the abrasion effect on internal particles is much smaller than that of fluidized bed reactors. Therefore, moving bed reactors are suitable for reactions that require medium mechanical properties of solid particles and require circulation, and are well matched with activated coke flue gas purification processes. Moving bed reactors have great advantages in terms of continuity and the degree of abrasion on activated coke particles, and moving bed reactors have strong flue gas adaptability. Moving bed reactors can be divided into three forms: cross-flow, parallel flow and counter-flow according to the different movement directions of flue gas and activated coke inside the reactor.

[0008] When the gas phase and the solid phase move in countercurrent, it is more conducive to the step-by-step adsorption reaction in the reactor, which can ensure the outlet flue gas purification effect and maximize the saturated working capacity of the activated coke at the reactor outlet.

[0009] The cross-flow moving bed activated coke desulfurization process mainly relies on the gravity of the coke itself to achieve slow movement. There will be blind spots for the movement of activated coke in the moving bed body, and the activated coke in some corners will be stored in certain areas for a long time due to the characteristics of the stacking angle, which affects the uniform and stable fall of the coke. The counter-flow moving bed is similar to the cross-flow moving bed, and both have the phenomenon of uneven coke fall. Summary of the invention

[0010] The technical problem solved by the present invention is that both fixed bed reactors and fluidized bed reactors have obvious disadvantages, while moving bed reactors can overcome the above-mentioned defects in some aspects. However, the existing co-current moving bed has a low working capacity of activated coke; counter-current moving bed and cross-current moving bed both have the phenomenon of uneven coke drop.

[0011] In order to solve the above technical problems, the present invention provides a moving bed reactor, wherein a gas inlet and a solid reactant outlet are arranged at the lower part of the moving bed reactor; a gas outlet and a solid reactant inlet are arranged at the upper part of the moving bed reactor; a horizontally rotatable turntable is arranged inside the moving bed reactor, and the turntable includes a sealed partition, a breathable partition and a distribution port; wherein the sealed partition blocks the passage of solid reactants and gas; the breathable partition blocks the passage of solid reactants but allows the passage of gas; and the distribution port allows the solid reactants to pass through.

[0012] During operation, the turntable rotates and the solid reactants on the turntable are in a relatively static state. The sealed partitions and breathable partitions prevent the solid reactants from falling, and the solid reactants can only flow down from the distribution port. Since the distribution port rotates with the turntable, the solid reactants fall evenly from the distribution port to the surface of the turntable of the next level, achieving uniform distribution.

[0013] Taking the flue gas desulfurization of activated coke as an example, in this scheme, the boiler flue gas is in countercurrent contact with the activated coke. The boiler flue gas with a higher sulfur concentration in the flue gas inlet area contacts and reacts with the activated coke close to the saturated working sulfur capacity, and the boiler flue gas with a lower sulfur concentration in the purified flue gas outlet area contacts and reacts with the newly added regenerated activated coke, ensuring the balanced and stable adsorption reaction rate of the activated coke in the entire tower body.

[0014] The turntable of the present invention rotates at a uniform speed. Since the closed partition cannot pass gas, the gas can only move upward from the air-permeable partition (the area of ​​the material distribution opening is generally very small, and the gas passing through can be ignored). This can guide the flue gas in the tower, so that the active coke in the tower can react with the flue gas evenly and completely, avoiding the formation of dead corners.

[0015] The moving bed reactor of the present invention divides the active coke in the tower into multiple step areas through a rotating disk, thereby realizing a multi-stage series adsorption reaction. The flue gas connection of different step areas is realized through the air permeable partition on the rotating disk, and there is no need to set up a series flue gas pipeline, thereby reducing construction land occupation and construction investment.

[0016] Preferably, the number of the turntables is more than two levels, and the turntables of each level are arranged at the upper and lower parts and are parallel to each other.

[0017] The activated coke in the reactor is divided into multiple stepped areas through a multi-stage turntable to achieve multi-stage series adsorption, ensuring the desulfurization effect of the outlet flue gas. At the same time, the saturated working sulfur capacity of the saturated coke outlet activated coke is maximized, extending the regeneration cycle of the activated coke.

[0018] Preferably, from bottom to top, the air permeable baffles of each stage of the rotating disk are arranged alternately with the air permeable baffles of the adjacent rotating disk, so that the gas is deflected and moves upward.

[0019] This arrangement enables the flue gas to flow in a curved manner (bend) within the tower body, extending the flue gas flow path and further achieving full contact between the flue gas and the activated coke.

[0020] Preferably, the area of ​​the air-permeable partition occupies 1 / 3 to 2 / 3 of the area of ​​the turntable. When the cloth opening is not considered, the area of ​​the air-permeable partition and the area of ​​the sealed partition both occupy 1 / 2 of the area of ​​the turntable.

[0021] Preferably, a transmission shaft is arranged at the center of the turntable, the turntable is driven to rotate by the transmission shaft, and a speed reducer is arranged on the top of the transmission shaft. Under the drive of the motor, the transmission shaft and the turntable are driven to rotate.

[0022] Preferably, a cloth piece is provided at the cloth opening.

[0023] The cloth opening is generally arranged at the junction of the breathable partition and the sealing partition.

[0024] The cloth sheet can be set to be tilted at a certain angle, and the tilt angle is set according to the particle size and type of the solid reactant and the relevant characteristics of the reactor. For example, the angle between the cloth sheet and the horizontal plane is 5-70 degrees.

[0025] When the angle between the cloth piece and the horizontal plane is 0 degrees, the cloth piece completely blocks the cloth opening, that is, there is no need to cloth downward temporarily. When the angle between the cloth piece and the horizontal plane is 90 degrees, the cloth opening is completely open. The downward inclination direction of the cloth piece side is preferably consistent with the rotation direction, which is conducive to the downward flow of materials.

[0026] In some technical solutions, the length of the fabric piece is equal to the radius of the turntable.

[0027] Preferably, the main structure of the moving bed reactor is cylindrical. Compared with the square structure, the cylindrical structure is more stable and requires less construction materials under the same volume.

[0028] In terms of the technology of flue gas desulfurization using activated coke, the gas inlet is the flue gas inlet, the gas outlet is the purified flue gas outlet, the solid reactant inlet is the regenerated coke inlet; and the solid reactant outlet is the saturated coke outlet.

[0029] The gas and the fixed reactant of the present invention refer to substances that can undergo physical adsorption or chemical reaction, wherein the solid reactant can also be a catalyst. The solid reactant can be in the form of particles or blocks.

[0030] It should be noted that, in the description of the positional relationship, the lower part of the present invention includes the bottom part, and the upper part includes the top part.

[0031] Compared with the existing moving bed reactor, the beneficial effects of the present invention are:

[0032] 1. The reactor is divided into multiple stepped areas by a turntable to achieve multi-stage series adsorption, ensuring the reaction effect. At the same time, the saturated working sulfur capacity of the activated coke at the saturated coke outlet is maximized, extending the regeneration cycle of the activated coke.

[0033] 2. The present invention guides the flue gas in the reactor by rotating the turntable, so that the active coke in the reactor can be uniformly and completely contacted with the flue gas to react, avoiding the occurrence of dead corners. Through rotation, the active coke flows out through the distribution port and is transported to the next layer, realizing the uniform and smooth transportation of the active coke and the cascade utilization of the active coke.

[0034] 3. The moving bed reactor of the present invention is a cylindrical tower structure. The cylindrical structure is more stable than the square structure, and under the condition of the same volume, less construction materials and land are required.

[0035] 4. The countercurrent contact between the gas and the solid reactant of the present invention ensures the balanced stability of the adsorption reaction rate of the activated coke in the entire reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a three-dimensional schematic diagram of a moving bed reactor according to an embodiment of the present invention.

[0037] Figure 2 The figure is a top view of a turntable of a moving bed reactor according to an embodiment of the present invention.

[0038] Reference numerals:

[0039] 1- solid reactant inlet; 2- gas outlet; 3- solid reactant outlet; 4- gas inlet; 5, turntable; 6- transmission shaft; 7- reducer;

[0040] 51- breathable partition; 52- airtight partition; 53- fabric opening; DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the embodiments.

[0042] Example

[0043] This embodiment provides a moving bed reactor, and its three-dimensional structure schematic diagram is as follows Figure 1 As shown, a gas inlet 4 and a solid reactant outlet 3 are provided at the lower part of the moving bed reactor; a gas outlet 2 and a solid reactant inlet 1 are provided at the upper part of the moving bed reactor;

[0044] A horizontally rotatable turntable 5 is arranged inside the moving bed reactor. There are three turntables 5 in total, which are evenly spaced and parallel to each other. Figure 2 As shown, the turntable 5 includes a breathable baffle 51, a sealed baffle 52 and a material distribution port 53; all of which are located on the plane of the turntable 5. Among them, the sealed baffle 52 blocks the solid reactant and gas from passing through; the breathable baffle 51 blocks the solid reactant from passing through, but allows the gas to pass through; the material distribution port 53 allows the solid reactant to pass through. The area occupied by the material distribution port 53 is very small and can be ignored compared with the breathable baffle 51 and the sealed baffle 52. The areas of the breathable baffle 51 and the sealed baffle 52 each occupy 1 / 2 of the area of ​​the turntable 5.

[0045] From bottom to top, the air permeable baffles 51 of each rotating disk are arranged alternately with the air permeable baffles 51 of the adjacent rotating disk, so that the gas is diverted and moves upward. Figure 1 As shown, the air-permeable partition 51 of the top turntable is located on the left, the air-permeable partition 51 of the second stage is located on the right, and the air-permeable partition 51 of the third stage is located on the left.

[0046] A transmission shaft 6 is arranged at the center of the rotating disk 5, and the rotating disk 5 is driven to rotate by the transmission shaft 6. A speed reducer 7 is arranged at the top of the transmission shaft. Driven by the motor, the speed reducer 7 drives the rotating disk 5 to rotate at a uniform speed.

[0047] In this embodiment, a distribution piece is provided at the distribution port, and the length of the distribution piece is equal to the radius of the turntable. The angle between the distribution piece and the horizontal plane is 30 degrees. The main structure of the moving bed reactor in this embodiment is cylindrical, and the lower part is conical.

[0048] In some embodiments, the angle of the fabric piece can be adjusted in real time to adapt to different reaction conditions at any time. Usually, it is fixed at a certain angle to ensure the stability of the reaction conditions.

[0049] When the moving bed reactor of this embodiment is used in the flue gas desulfurization technology using activated coke, the gas inlet 4 is the flue gas inlet, the gas outlet 2 is the purified flue gas outlet, the solid reactant inlet 1 is the regenerated coke inlet, and the solid reactant outlet 3 is the saturated coke outlet.

[0050] In this embodiment, the reactor is divided into multiple stepped areas by a turntable, achieving multi-stage series adsorption, ensuring the reaction effect, and at the same time maximizing the saturated working sulfur capacity of the activated coke at the saturated coke outlet, extending the regeneration cycle of the activated coke. The flue gas in the reactor is diverted by the rotation of the turntable, so that the active coke in the reactor is uniformly and completely in contact with the flue gas to react, avoiding the occurrence of dead corners. Through rotation, the active coke flows out through the distribution port and is transported to the next layer, achieving uniform and smooth transportation of the active coke and the stepped utilization of the active coke.

Claims

1. A moving bed reactor, wherein a gas inlet and a solid reactant outlet are provided at the lower part of the moving bed reactor; a gas outlet and a solid reactant inlet are provided at the upper part of the moving bed reactor; It is characterized in that A horizontally rotatable turntable is arranged inside the moving bed reactor, and the turntable comprises a sealed baffle, a breathable baffle and a material distribution port; Among them, the closed partition blocks the solid reactants and gas from passing through; the breathable partition blocks the solid reactants from passing through, but allows gas to pass through; the cloth port allows the solid reactants to pass through; From bottom to top, the air-permeable baffles of each level of the rotating disk are staggered with the air-permeable baffles of the adjacent rotating disk, so that the gas is diverted and moves upward; The cloth opening is arranged at the junction of the air-permeable partition and the sealing partition; A cloth piece is provided at the cloth opening; The length of the fabric piece is equal to the radius of the turntable; The angle between the fabric sheet and the horizontal plane is 5-70 degrees.

2. The moving bed reactor according to claim 1, characterized in that: The number of the rotating disks is more than two levels, and the rotating disks of each level are arranged at the upper and lower parts and are parallel to each other.

3. The moving bed reactor according to claim 1, characterized in that: The area of ​​the air-permeable partition occupies 1 / 3 to 2 / 3 of the area of ​​the turntable.

4. The moving bed reactor according to claim 1, characterized in that: A transmission shaft is arranged at the center of the turntable, and the turntable is driven to rotate by the transmission shaft. A reducer is arranged on the top of the transmission shaft.

5. The moving bed reactor according to any one of claims 1 to 4, characterized in that: The main structure of the moving bed reactor is cylindrical.

6. The moving bed reactor according to any one of claims 1 to 4, characterized in that: The gas inlet is a flue gas inlet, the gas outlet is a purified flue gas outlet, the solid reactant inlet is a regenerated coke inlet; and the solid reactant outlet is a saturated coke outlet.

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