Efficient desulfurization system of alkali recovery furnace

Abstract

The utility model discloses an efficient desulfurization system of an alkali recovery furnace, which comprises the alkali recovery furnace, the alkali recovery furnace is connected with a waste gas inlet fixedly arranged on an absorption tower through a connecting pipeline, and the alkali recovery furnace enters the absorption tower through an induced draft fan arranged on the connecting pipeline and reacts with desulfurization liquid in the absorption tower. The absorption tower is connected with a factory desulfurization liquid preparation workshop through a connecting pipeline or is connected with a desulfurization liquid storage tank arranged near the absorption tower through a connecting pipeline, a leading-out pipeline is arranged on the absorption tower, and part of desulfurization liquid is discharged to a factory waste liquid treatment center for treatment through the leading-out pipeline. Two spraying layer groups are arranged in the absorption tower at intervals, each spraying layer group comprises at least four independent spraying layers, a demisting layer is arranged at the position, close to an outlet of the absorption tower, above the absorption tower, and the demisting layer is a rotational flow demisting layer.

Description

Technical Field

[0001] The utility model belongs to the technical field of industrial tail gas, and particularly relates to an efficient desulfurization system for an alkali recovery furnace. Background Art

[0002] An alkali recovery furnace uses the waste liquid (black liquor) discharged after washing pulp by the alkali method. After concentration, it is used as fuel and sent into the furnace for combustion. By absorbing the heat of the high-temperature flue gas discharged from the combustion, steam is generated. After the black liquor burns, the liquid slag is discharged from the furnace bottom and restored to alkali after causticization. It can not only recover the alkali used in papermaking (the recovery rate of the furnace body reaches 99%), but also supply heat and generate electricity, achieving the comprehensive effects of recovery, energy conservation, and pollution reduction.

[0003] The main components of the alkali furnace flue gas are mainly SO, NO, particulate matter, etc., and there is also a large amount of water vapor, etc. In order to solve the problems of large content and non-compliance of the alkali recovery furnace flue gas, in the prior art, the commonly used wet desulfurization technologies for coal-fired boilers, such as the calcium method, magnesium method, and ammonia method, or dry and semi-dry desulfurization technologies are adopted. Although good desulfurization effects can be achieved, they will bring difficulties in the treatment of desulfurization by-products.

[0004] Moreover, the existing technologies that adopt various wet or dry and semi-dry desulfurization technologies such as the calcium method, magnesium method, and ammonia method have high costs, large floor areas, and high energy consumption.

[0005] In view of the above factors, an efficient desulfurization system for an alkali recovery furnace is specially designed, which has a simple and reliable system, a small floor area, a low operating cost, and can achieve the purpose of desulfurization compliance while having a low cost. Content of the Utility Model

[0006] The purpose of the utility model is to provide an efficient desulfurization system for an alkali recovery furnace to solve the problems raised in the above background art.

[0007] The purpose of the utility model is realized by the following technical solutions: An efficient desulfurization system for an alkali recovery furnace includes an alkali recovery furnace. The alkali recovery furnace is connected to the waste gas inlet fixedly arranged on the absorption tower through a connecting pipeline. The alkali recovery furnace enters the absorption tower through an induced draft fan arranged in the connecting pipeline and reacts with the desulfurization liquid in the absorption tower. After dehydration and demisting, it is connected to the factory chimney for discharge;

[0008] The absorption tower is connected to the factory desulfurization liquid preparation workshop through a connecting pipeline or is connected to a desulfurization liquid storage tank arranged near the absorption tower through a connecting pipeline. An extraction pipeline is arranged on the absorption tower, and part of the desulfurization liquid is discharged through the extraction pipeline to the factory waste liquid treatment center for disposal.

[0009] Further, two spray layer groups are arranged at intervals in the absorption tower, and each spray layer group includes at least 4 independent spray layers.

[0010] Further, a demisting layer is arranged above the absorption tower near the outlet of the absorption tower, and the demisting layer is a cyclone demisting layer.

[0011] Further, a number of nozzles are arranged on the independent spray layer at intervals. The independent spray layer adopts an internal circulation absorption method and is pumped from the absorption tower to the independent spray layer by a circulation pump, and is atomized by the nozzles on the independent spray layer.

[0012] Further, the independent spray layer is connected to the bottom of the absorption tower along the outside of the absorption tower through a connecting pipe, and a circulation pump is arranged on each independent spray layer.

[0013] Further, a slurry discharge pump is arranged on the lead-out pipe, and part of the desulfurized liquid is discharged to the waste liquid treatment center of the factory area through the slurry discharge pump for disposal.

[0014] Further, an activated carbon adding device is also arranged on the connecting pipe between the alkali recovery furnace and the absorption tower for adding activated carbon into the flue.

[0015] Further, the activated carbon adding device is of a drawer type structure, and an air inlet channel and an air outlet channel are arranged at both ends of the activated carbon adding device.

[0016] Further, a cyclone separator is also arranged on the connecting pipe between the alkali recovery furnace and the absorption tower, and the cyclone separator is arranged upstream of the activated carbon adding device.

[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0018] In the absorption section of the present utility model, there are no other devices except the nozzles, which reduces the probability of fouling, blockage and wear, improves the availability of the equipment, and reduces the maintenance workload.

[0019] The present utility model has a low resistance in the tower and low energy consumption of the fan. By arranging multiple independent spray layers, the operation mode can be flexibly adjusted according to the changes of the unit load and the SO2 concentration, and a stable desulfurization efficiency can be maintained.

[0020] The system of the present utility model is simple and reliable, occupies a small area, has a low operation cost, and can achieve the purpose of desulfurization up to standard while having a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic connection diagram of the alkali recovery furnace and the absorption tower of the present utility model;

[0022] Figure 2 is a schematic connection diagram of the present utility model with an activated carbon adding device and a cyclone separator;

[0023] Figure 3 is a schematic diagram of the absorption tower of the present utility model. Detailed implementation manners

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0025] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" 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 direct connection, or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0026] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0027] As Figures 1-3 shown, an efficient desulfurization system for an alkali recovery furnace includes an alkali recovery furnace 1. The alkali recovery furnace 1 is connected to the waste gas inlet fixedly arranged on an absorption tower 2 through a connecting pipeline. The alkali recovery furnace 1 enters the absorption tower 2 through a induced draft fan arranged in the connecting pipeline and reacts with the desulfurization liquid in the absorption tower 2, and is discharged to the factory chimney 3 after dehydration and demisting;

[0028] The absorption tower 2 is connected to the factory desulfurization liquid preparation workshop through a connecting pipeline or is connected to a desulfurization liquid storage tank arranged near the absorption tower 2 through a connecting pipeline. An extraction pipeline is arranged on the absorption tower 2, and part of the desulfurization liquid is discharged to the factory waste liquid treatment center 6 through the extraction pipeline.

[0029] In order to facilitate flexibly adjusting the operation mode according to the changes of the unit load and SO2 concentration during the use state and maintaining a stable desulfurization efficiency, two spray layer groups 4 are arranged at intervals in the absorption tower 2, and each spray layer group 4 includes at least 4 independent spray layers.

[0030] A demisting layer 5 is arranged above the absorption tower 2 near the outlet of the absorption tower 2, and the demisting layer 5 is a cyclone demisting layer.

[0031] The absorption tower 2 removes mist based on the function of the swirl plate to change the axial flow into swirl flow and the centrifugal force generated by the swirl flow. The contact between gas and liquid is strengthened by the centrifugal force, so that the liquid droplets are driven by the gas flow to rotate.

[0032] A number of nozzles 7 are arranged at intervals on the independent spray layer. The independent spray layer adopts an internal circulation absorption method and is pumped from the absorption tower 2 to the independent spray layer by a circulation pump, and is atomized by the nozzles 7 on the independent spray layer.

[0033] The independent spray layer is connected to the bottom of the absorption tower 2 along the outside of the absorption tower 2 through a connecting pipe, and a circulation pump 8 is arranged on each independent spray layer.

[0034] In order to simplify the treatment process in the use state and avoid adding additional treatment equipment, a slurry discharge pump is arranged on the lead-out pipe, and part of the desulfurized liquid is discharged to the factory waste liquid treatment center for disposal through the slurry discharge pump.

[0035] In order to facilitate secondary filtration of the flue gas by setting an activated carbon adding device 9 in the use state, an activated carbon adding device 9 is also arranged on the connecting pipe between the alkali recovery furnace 1 and the absorption tower 2, and is used to add activated carbon into the flue duct.

[0036] The activated carbon adding device 9 has a drawer-type structure, and an air inlet channel and an air outlet channel are arranged at both ends of the activated carbon adding device 9.

[0037] In order to facilitate primary filtration of the coarse particles discharged from the alkali recovery furnace 1 by a cyclone separator 10 in the use state, a cyclone separator 10 is also arranged on the connecting pipe between the alkali recovery furnace 1 and the absorption tower 2, and the cyclone separator 10 is arranged upstream of the activated carbon adding device 9.

[0038] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0039] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An alkali recovery furnace high-efficiency desulfurization system, comprising an alkali recovery furnace (1), characterized in that: The alkali recovery furnace (1) is connected to the exhaust gas inlet fixedly arranged on the absorption tower (2) through a connecting pipe. The alkali recovery furnace (1) enters the absorption tower (2) through the induced draft fan arranged in the connecting pipe and reacts with the desulfurization liquid in the absorption tower (2). After dehydration and demisting, the exhaust gas is connected to the factory chimney (3) for discharge; The absorption tower (2) is connected to the desulfurization liquid preparation workshop in the factory through a connecting pipeline or is connected to the desulfurization liquid storage tank arranged near the absorption tower (2) through a connecting pipeline. The absorption tower (2) is provided with an outlet pipeline, and the outlet pipeline discharges part of the desulfurization liquid to the factory waste liquid treatment center for disposal (6).

2. The alkali recovery furnace high-efficiency desulfurization system according to claim 1 is characterized in that: Two spray layer groups (4) are arranged at intervals in the absorption tower (2), and each spray layer group (4) includes at least four independent spray layers.

3. The alkali recovery furnace high-efficiency desulfurization system according to claim 2 is characterized in that: A demisting layer (5) is arranged above the absorption tower (2) near the outlet of the absorption tower (2), and the demisting layer (5) is a cyclone demisting layer.

4. The alkali recovery furnace high-efficiency desulfurization system according to claim 3 is characterized in that: The independent spray layer is provided with a plurality of nozzles (7) arranged at intervals. The independent spray layer adopts an internal circulation absorption method, and a circulation pump is used to pump water from the absorption tower (2) to the independent spray layer, and the water is atomized by the nozzles (7) in the independent spray layer.

5. The alkali recovery furnace high-efficiency desulfurization system according to claim 4 is characterized in that: The independent spray layers are connected to the bottom of the absorption tower (2) through a connecting pipe along the outside of the absorption tower (2), and a circulation pump (8) is provided on each independent spray layer.

6. The alkali recovery furnace high-efficiency desulfurization system according to claim 5 is characterized in that: The outlet pipeline is provided with a slurry discharge pump, through which part of the desulfurized liquid is discharged to the waste liquid treatment center in the plant for disposal.

7. The alkali recovery furnace high-efficiency desulfurization system according to claim 6 is characterized in that: An activated carbon adding device (9) is also provided on the connecting pipe between the alkali recovery furnace (1) and the absorption tower (2) for adding activated carbon into the flue.

8. The alkali recovery furnace high-efficiency desulfurization system according to claim 7 is characterized in that: The activated carbon adding device (9) is a drawer-type structure, and an air inlet and an air outlet are provided at both ends of the activated carbon adding device (9).

9. The alkali recovery furnace high-efficiency desulfurization system according to claim 8 is characterized in that: A cyclone separator (10) is also provided on the connecting pipeline between the alkali recovery furnace (1) and the absorption tower (2), and the cyclone separator (10) is provided upstream of the activated carbon adding device (9).

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