Device for controlling water slag filter layer compaction by bypass membrane filtration

Abstract

The utility model relates to a device for controlling filter layer compaction of by-pass membrane filtration control water slag, belongs to the blast furnace ironmaking slag processing technical field. Increase the side filtration unit in the existing bottom filtration method slag flushing system, including all connection in the side filtration main pipe on the slag flushing cold water pool, side filtration effluent pipe, be equipped with side filtration pump group, by-pass membrane filtration unit and be used for monitoring the electric conductivity instrument of slag flushing water electric conductivity on the side filtration main pipe. Through the membrane filtration to the slag flushing circulating water in the slag flushing cold water pool regularly, the circulating water after the side filtration treatment returns to the slag flushing cold water pool through the side filtration effluent pipe, continuous operation, and the conductivity of water flow is determined to detect the salt content in water flow, can significantly reduce the salt content in the water quality of slag flushing circulating system, effectively slow down even avoid the enrichment and crystallization of calcium magnesium ion, silicate and other substances at the filtration interface, fundamentally alleviate the filter layer compaction problem, prolong the filter layer service life, reduce the adverse effect of filter material replacement on the continuous production of blast furnace.

Description

Technical Field

[0001] This utility model belongs to the field of blast furnace slag treatment technology, and relates to a device for controlling the caking of water slag filter bed through bypass membrane filtration. Background Technology

[0002] Blast furnace slag, an unavoidable byproduct of ironmaking, is directly related to the environmental performance and resource recycling efficiency of steel enterprises through its treatment. Currently, the industry commonly uses water-quenched slag technology to rapidly cool high-temperature molten slag, and then uses slag-water separation technology to achieve slag particle recovery and water resource recycling. From a process principle perspective, slag-water separation mainly falls into two technical routes: mechanical filtration and bottom filtration. Bottom filtration, with its unique fluidized bed filtration mechanism, demonstrates significant advantages in practical applications: by constructing a porous media filter layer, it effectively removes most suspended solids from the water through the synergistic effect of gravity settling and media interception, significantly outperforming the effluent indicators of mechanical filtration. Furthermore, this process system has a simple structure, low power consumption, high equipment operating rate, and does not require frequent filter media replacement, resulting in lower operating costs than mechanical methods, making it the preferred solution for most steel enterprises.

[0003] However, the bottom filtration method has gradually revealed a technical bottleneck in filter bed caking during long-term operation. Essentially, this is closely related to the unique water quality of the slag flushing circulating water: after water quenching, blast furnace slag has a high concentration of dissolved calcium and magnesium ions, and also contains soluble silica. During continuous operation of the filtration system, with the periodic changes in water temperature, according to the solubility product rule, calcium and magnesium ions easily react with carbonate and hydroxide ions in the water to form crystalline substances such as calcium carbonate and magnesium hydroxide. These microcrystalline particles continuously deposit in the pores of the filter bed, forming a dense crystalline layer. Simultaneously, silicates undergo polymerization in an alkaline environment, generating negatively charged silica colloids. These colloids aggregate on the surface of the filter media through electrostatic adsorption, gradually forming a silicate gel membrane layer.

[0004] The aforementioned dual effects lead to irreversible changes in the physical structure of the filter layer: the originally loose porous medium gradually evolves into a dense, compacted body, with reduced porosity and decreased permeability. This change not only causes a surge in filtration resistance, forcing a significant increase in the energy consumption of the circulating water pump, but more seriously, it disrupts the hydraulic balance of the filtration system, resulting in insufficient backwash water and deteriorated backwashing effect, forming a vicious cycle of "compaction - backwashing failure - accelerated compaction." In extreme cases, the filter layer completely loses its filtration function, forcing the blast furnace to shut down for maintenance, causing enormous economic losses.

[0005] Current engineering practices primarily address filter bed caking through two methods: chemical cleaning and physical replacement. However, both have significant limitations: chemical cleaning requires strong acids or chelating agents, which, while dissolving some crystals, corrode the filter media structure and generate wastewater containing heavy metals, causing secondary pollution; physical replacement, on the other hand, faces challenges such as high workload and long replacement cycles, severely impacting production continuity. Therefore, there is an urgent need to develop an innovative technical solution to effectively alleviate the critical problem of filter bed caking. Utility Model Content

[0006] In view of this, the purpose of this utility model is to provide a device for controlling the caking of water sludge filter bed through bypass membrane filtration, thereby reducing the salt content in the flushing water from the source and effectively solving the problem of filter bed caking.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A device for controlling the caking of water sludge filter bed by bypass membrane filtration includes a bypass filtration unit whose inlet end and outlet end are both connected to a cooling unit. The bypass filtration unit includes a bypass filtration main pipe and a bypass filtration outlet pipe. The inlet end of the bypass filtration main pipe is connected to the cooling unit, the outlet end of the bypass filtration main pipe is connected to the inlet end of the bypass filtration outlet pipe, and the outlet end of the bypass filtration outlet pipe is connected to the cooling unit.

[0009] The bypass filtration main pipe is sequentially equipped with a bypass filtration pump group and a bypass membrane filtration unit; the inlet end of the bypass filtration pump group is equipped with a bypass filtration shut-off valve, and the outlet end of the bypass filtration pump group is equipped with a bypass filtration pump outlet valve; the bypass filtration main pipe is also equipped with a first conductivity meter, which is used to monitor the conductivity of the circulating water in the bypass filtration main pipe.

[0010] A side filter outlet valve is provided at one end of the side filter outlet pipe near the cooling unit;

[0011] The flushing water in the cooling unit circulates through the main side filter pipe and the side filter outlet pipe, and the conductivity of the circulating water in the pipe is monitored by the conductivity meter to reduce the salt content of the flushing water in the cooling unit.

[0012] Optionally, the cooling unit includes a cooling tower, a slag flushing cold water pool, a slag flushing pump set, and a granulation main pipe connected in sequence along the water flow direction.

[0013] Optionally, a second conductivity meter is provided on the granulation manifold to monitor the conductivity of the circulating water in the granulation manifold.

[0014] Optionally, the inlet end of the side filter main pipe is connected to the bottom of the slag flushing cold water tank, and the outlet end of the side filter outlet pipe is connected to the top of the slag flushing cold water tank.

[0015] Optionally, the outlet end of the slag flushing pump unit is equipped with a slag flushing pump outlet valve.

[0016] Optionally, it also includes an upper tower pump set connected to the inlet end of the cooling unit and a water slag tank connected to the outlet end of the cooling unit. The outlet end of the water slag tank is sequentially connected to the filter tank and the upper tower pump set. The outlet end of the upper tower pump set is connected to the inlet end of the cooling tower. The outlet end of the flushing pump set is connected to the inlet end of the water slag tank and the hot water main pipe, respectively. The flushing water sequentially passes through the flushing pump set, water slag tank, filter tank, and upper tower pump set of the cooling unit and returns to the cooling tower of the cooling unit to realize the circulation of the flushing water.

[0017] Optionally, the filter tank and the upper tower pump unit are connected via a hot water main pipe, and the outlet end of the cooling unit is connected to the inlet end of the hot water main pipe.

[0018] Optionally, a hot water valve is provided at the inlet end of the hot water main pipe.

[0019] Optionally, the inlet end of the slag tank is equipped with a slag flushing point water supply valve; the outlet end of the upper tower pump unit is equipped with an upper tower pump outlet valve.

[0020] Optionally, a filter layer is provided at the bottom of the filter tank.

[0021] The beneficial effects of this utility model are as follows:

[0022] This invention adds a side-filter unit to the existing bottom-filtration slag flushing system. The side-filter unit includes a main side-filter pipe and a side-filter outlet pipe. Both the inlet end of the main side-filter pipe and the outlet end of the outlet pipe are connected to the slag flushing cold water tank. The main side-filter pipe is also equipped with a side-filter pump set, a bypass membrane filtration unit, and a conductivity meter for measuring the conductivity of the slag flushing water in the monitoring pipe. The side-filter unit can periodically perform membrane filtration on the slag flushing circulating water in the slag flushing cold water tank. The circulating water treated by the side-filter returns to the slag flushing cold water tank through the side-filter outlet pipe, operating continuously. Combined with the measurement of the water flow conductivity to detect the salt content in the water flow, it can significantly reduce the salt content in the slag flushing circulating water of the slag flushing circulation system, slowing down or even inhibiting the enrichment and crystallization of calcium and magnesium ions, silicates, and other substances at the filter interface from the source, significantly alleviating the problem of filter bed caking and extending the service life of the filter bed.

[0023] The overall device of this utility model has a simple structure, is easy to implement, and has low investment and operating costs, making it highly economical. It is also highly adaptable and can be flexibly applied to the upgrading and optimization of existing blast furnace bottom filtration systems, making it widely applicable and easy to promote industrialization.

[0024] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0026] Figure 1 This is a schematic diagram of the overall device of this utility model.

[0027] Figure label:

[0028] 1. Bypass filter main pipe, 2. First conductivity meter, 3. Bypass filter shut-off valve, 4. Bypass filter pump set, 5. Bypass filter pump outlet valve, 6. Bypass membrane filter unit, 7. Bypass filter outlet pipe, 8. Bypass filter outlet valve, 9. Slag tank, 10. Slag flushing point water supply valve, 11. Upper tower pump set, 12. Upper tower pump outlet valve, 13. Filter tank, 14. Filter layer, 15. Hot water main pipe, 16. Hot water valve, 17. Cooling tower, 18. Slag flushing cold water tank, 19. Slag flushing pump set, 20. Slag flushing pump outlet valve, 21. Granulation main pipe, 22. Second conductivity meter. Detailed Implementation

[0029] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0031] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0032] Please see Figure 1 This is a device for controlling the caking of water sludge filter bed through bypass membrane filtration. It includes a bypass filter unit with both its inlet and outlet ends connected to a cooling unit, an upper tower pump group 11 connected to the inlet end of the cooling unit, and a water sludge tank 9 connected to the outlet end of the cooling unit. The outlet end of the water sludge tank 9 is connected in sequence to a filter tank 13 and an upper tower pump group 11. The flushing water returns to the cooling unit in sequence through the cooling unit, the water sludge tank 9, the filter tank 13, and the upper tower pump group 11, thus realizing the circulation of the flushing water.

[0033] The bypass filtration unit includes a bypass filtration main pipe 1 and a bypass filtration outlet pipe 7. The inlet end of the bypass filtration main pipe 1 is connected to the cooling unit, and the outlet end of the bypass filtration main pipe 1 is connected to the inlet end of the bypass filtration outlet pipe 7. The outlet end of the bypass filtration outlet pipe 7 is connected to the cooling unit. A bypass filtration pump group 4 and a bypass membrane filtration unit 6 are sequentially installed on the bypass filtration main pipe 1. A bypass filtration shut-off valve 3 is installed at the inlet end of the bypass filtration pump group 4, and a bypass filtration pump outlet valve 5 is installed at the outlet end of the bypass filtration pump group 4. A first conductivity meter 2 is also installed on the bypass filtration main pipe 1. A bypass filtration outlet valve 8 is installed at the end of the bypass filtration outlet pipe 7 near the cooling unit. The bypass filtration process is regulated by the bypass filtration shut-off valve 3, the bypass filtration pump outlet valve 5, and the bypass filtration outlet valve 8 working together.

[0034] Before performing bypass membrane filtration (i.e., starting the bypass membrane filtration unit 6), the bypass main shut-off valve 3, the bypass pump group 4, and the bypass pump outlet valve 5 must be opened in sequence. After the bypass membrane filtration unit 6 has started stably, the bypass outlet valve 8 can be opened.

[0035] The cooling unit includes a cooling tower 17, a slag flushing cold water pool 18, a slag flushing pump group 19, and a granulation main pipe 21 connected sequentially along the water flow direction. A second conductivity meter 22 is installed on the granulation main pipe 21. When the conductivity measured by the second conductivity meter 22 is ≥500 μs / cm, a signal is issued allowing the bypass filtration to start. The limit value of the second conductivity meter 22 can be manually input and set on the control system. The slag flushing circulating water in the cooling unit circulates in the bypass filtration main pipe 1 and the bypass filtration outlet pipe 7. After the bypass filtration circulation process starts, the conductivity of the circulating water in the bypass filtration main pipe 1 and the granulation main pipe 21 is monitored simultaneously using the first conductivity meter 2 and the second conductivity meter 22 until the bypass filtration circulation process continues until the conductivity reaches the manually set value, thereby reducing the salt content of the slag flushing water in the cooling unit. In some embodiments of this utility model, the preferred measuring range of the first conductivity meter 2 and the second conductivity meter 22 is 0–5000 μs / cm.

[0036] The filter tank 13 and the upper tower pump set 11 are connected via a hot water main pipe 15, with a hot water valve 16 at the inlet end of the hot water main pipe 15. The outlet end of the upper tower pump set 11 is connected to the inlet end of the cooling tower 17; the outlet end of the slag flushing pump set 19 is connected to the inlet end of the slag tank 9 and the hot water main pipe 15, respectively. The inlet end of the side filter main pipe 1 is connected to the bottom of the slag flushing cold water tank 18, and the outlet end of the side filter outlet pipe 7 is connected to the top of the slag flushing cold water tank 18. The outlet end of the slag flushing pump set 19 is equipped with a slag flushing pump outlet valve 20; the inlet end of the slag tank 9 is equipped with a slag flushing point water supply valve 10; the outlet end of the upper tower pump set 11 is equipped with an upper tower pump outlet valve 12; and a filter layer 14 is provided at the bottom of the filter tank 13. The circulation of slag flushing water in the overall pipeline is regulated collaboratively by the slag flushing point water supply valve 10, the hot water valve 16, the upper tower pump outlet valve 12, and the slag flushing pump outlet valve 20.

[0037] This invention adds a side-filter unit to the existing bottom filtration slag flushing system. The side-filter unit includes a side-filter main pipe 1 and a side-filter outlet pipe 7. The inlet end of the side-filter main pipe 1 and the outlet end of the side-filter outlet pipe 7 are both connected to the slag flushing cold water tank 18. The side-filter main pipe 1 is also equipped with a side-filter pump group 4, a bypass membrane filtration unit 6, a first conductivity meter 2 for measuring the conductivity of the slag flushing water in the monitoring water pipe, and a second conductivity meter installed on the granulation main pipe 21. The side-filter unit can periodically perform membrane filtration on the slag flushing circulating water in the slag flushing cold water tank 18. The circulating water treated by the side-filter returns to the slag flushing cold water tank 18 through the side-filter outlet pipe 7, operating continuously. By measuring the conductivity of the water flow to detect the salt content in the water flow, it can significantly reduce the salt content in the slag flushing circulating water of the slag flushing circulation system, slowing down or even inhibiting the enrichment and crystallization of calcium and magnesium ions, silicates and other substances at the filtration interface from the source, significantly alleviating the problem of filter layer 14 caking and extending the service life of filter layer 14.

[0038] The overall device of this utility model has a simple structure, is easy to implement, and has low investment and operating costs, making it highly economical. It is also highly adaptable and can be flexibly applied to the upgrading and optimization of existing blast furnace bottom filtration systems, making it widely applicable and easy to promote industrialization.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A device for controlling the caking of water sludge filter bed in bypass membrane filtration, characterized in that: The system includes a bypass filter unit with both its inlet and outlet ends connected to the cooling unit. The bypass filter unit includes a bypass filter main pipe (1) and a bypass filter outlet pipe (7). The inlet end of the bypass filter main pipe (1) is connected to the cooling unit, the outlet end of the bypass filter main pipe (1) is connected to the inlet end of the bypass filter outlet pipe (7), and the outlet end of the bypass filter outlet pipe (7) is connected to the cooling unit. The bypass filter main pipe (1) is provided with a bypass filter pump group (4) and a bypass membrane filter unit (6) in sequence; the inlet end of the bypass filter pump group (4) is provided with a bypass filter shut-off valve (3), and the outlet end of the bypass filter pump group (4) is provided with a bypass filter pump outlet valve (5); the bypass filter main pipe (1) is also provided with a first conductivity meter (2), which is used to monitor the conductivity of the circulating water in the bypass filter main pipe (1); The side filter water outlet pipe (7) is provided with a side filter water outlet valve (8) at one end near the cooling unit.

2. The device for controlling the caking of water sludge filter bed by bypass membrane filtration according to claim 1, characterized in that: The cooling unit includes a cooling tower (17), a slag flushing cold water pool (18), a slag flushing pump group (19), and a granulation manifold (21) connected in sequence along the water flow direction.

3. The device for controlling the caking of water sludge filter bed according to claim 2, characterized in that: A second conductivity meter (22) is installed on the granulation manifold (21) to monitor the conductivity of the circulating water in the granulation manifold (21).

4. The device for controlling the caking of water sludge filter bed by bypass membrane filtration according to claim 2, characterized in that: The inlet end of the side filter main pipe (1) is connected to the bottom of the slag flushing cold water tank (18), and the outlet end of the side filter outlet pipe (7) is connected to the top of the slag flushing cold water tank (18).

5. The device for controlling the caking of water sludge filter bed by bypass membrane filtration according to claim 2, characterized in that: The outlet end of the slag flushing pump set (19) is equipped with a slag flushing pump outlet valve (20).

6. The device for controlling the caking of water sludge filter bed according to claim 2, characterized in that: It also includes an upper tower pump group (11) connected to the inlet end of the cooling unit, and a water slag tank (9) connected to the outlet end of the cooling unit. The outlet end of the water slag tank (9) is connected to the filter tank (13) and the upper tower pump group (11) in sequence. The outlet end of the upper tower pump group (11) is connected to the inlet end of the cooling tower (17). The outlet end of the flushing pump group (19) is connected to the inlet end of the water slag tank (9) and the hot water main pipe (15) respectively. The flushing water passes through the flushing pump group (19), water slag tank (9), filter tank (13), and upper tower pump group (11) of the cooling unit in sequence and returns to the cooling tower (17) of the cooling unit to realize the circulation of flushing water.

7. The device for controlling the caking of water sludge filter bed in bypass membrane filtration according to claim 6, characterized in that: The filter tank (13) and the upper tower pump group (11) are connected through the hot water main pipe (15), and the outlet end of the cooling unit is connected to the inlet end of the hot water main pipe (15).

8. The device for controlling the caking of water sludge filter bed according to claim 7, characterized in that: The hot water main pipe (15) is equipped with a hot water valve (16) at its inlet end.

9. The device for controlling the caking of water sludge filter bed according to claim 6, characterized in that: The inlet end of the slag tank (9) is provided with a slag flushing point water supply valve (10); the outlet end of the upper tower pump group (11) is provided with an upper tower pump outlet valve (12).

10. The device for controlling the caking of water sludge filter bed according to claim 6, characterized in that: The bottom of the filter tank (13) is provided with a filter layer (14).

Images