CN220110799U - Steel mill demineralized water ultrafiltration device backwash system - Google Patents

Abstract

The utility model discloses a backwashing system of a demineralized water ultrafiltration device of a steel mill, which comprises an ultrafiltration tank, a water inlet pipeline, a water outlet pipeline and a backwashing pipeline, wherein the end part of the water outlet pipeline is connected with a clean water tank, the backwashing pipeline comprises a backwashing pipe, a gas washing pipe, an adjusting pipe, an exhaust pipe and a blow-down pipe, one end of the backwashing pipe is communicated with the water inlet tank, the other end of the backwashing pipe is communicated with a water outlet, a backwashing pump and a backwashing valve are arranged on the backwashing pipe, one end of the gas washing pipe is communicated with a water inlet, the other end of the backwashing pipe is communicated with a compressed air storage tank, an air inlet valve is arranged on the gas washing pipe, the adjusting pipe is arranged at the upper part of the ultrafiltration tank, the adjusting pipe is provided with an adjusting valve, the exhaust pipe is arranged on the water outlet pipeline, the blow-down pipe is arranged at the bottom of the ultrafiltration tank, and the blow-down pipe is provided with a blow-down valve. The device not only improves the backwashing effect, but also has long running period after backwashing, improves the water yield after backwashing, and improves the water yield after backwashing by 10% on the basis of the original structure.

Description

Steel mill demineralized water ultrafiltration device backwash system

Technical Field

The utility model belongs to the technical field of steelmaking production equipment, and particularly relates to a backwashing system of a demineralized water ultrafiltration device of a steel mill.

Background

Iron and steel enterprises produce a large amount of industrial wastewater in the production process, and the wastewater has high salt content and needs desalination treatment to be recycled. The process flow of the demineralized water system operated by the current steel mill is as follows: raw water, a raw water pond, a multi-medium filter, an activated carbon filter, a self-cleaning filter, an ultrafiltration device, an ultrafiltration water producing pond, an ultrafiltration water producing pump, a primary reverse osmosis device, an intermediate pond, an intermediate water pump, a secondary reverse osmosis device, a pure water pond, an EDI water inlet pump, an EDI device, a desalting water pond and a desalting water pump. In the above treatment process flow, the ultrafiltration system is an important purification device, plays a role in supporting up and down, plays a vital role on the quality of the inflow water of the downstream (RO), the working principle of the existing ultrafiltration membrane filtration device is that water is usually introduced from the bottom of the water purification device, the water flows to the bottom of the device under the action of pressure, the water in the flowing process passes through the ultrafiltration membrane to be purified, organic matters, colloid matters, inorganic scaling matters, microorganisms and the like in the desalted water are all trapped on the surface of the ultrafiltration membrane in the using process of the existing ultrafiltration membrane filtration device, and along with the accumulation of the filtration time, the filter cake layer on the surface of the ultrafiltration membrane is thicker and denser, so that the filtration flux of the ultrafiltration membrane is reduced, and the ultrafiltration membrane is required to be reversely washed for 40-60 minutes generally, so that the membrane flux is recovered. In the prior art, the back washing of the ultrafiltration membrane adopts air and water to scrub and rinse algae particle colloid adsorbed by positive flow, however, because the pressure of the adopted compressed air is unstable and the pressure of the air is smaller than that of a backwash water pump, air can often enter the ultrafiltration membrane in the process of back washing, so that air scrubbing is invalid, the back washing effect of ultrafiltration is poor, in addition, the water quantity of the general back washing is 2-3 times of the water quantity of filtration, the back washing pressure is 2 times of the filtration pressure, the back washing duration is generally 3-5 minutes, so that the water yield of filtration is partially used for back washing by adopting hydraulic back washing, the water yield is reduced, the actual water yield is lower than 90 percent, in addition, the back washing pressure and the water flow rate are high, the corresponding power of a back washing pump is also high, the energy consumption is increased, more importantly, the flux of the ultrafiltration membrane cannot be recovered by 100 percent, after one filtration cycle, the flux is recovered to 99 percent, and the process of accumulation month only can cause the change of water yield resistance, so that the production requirement cannot be met. Therefore, the steel mill demineralized water ultrafiltration device backwashing system which is easy to control, can effectively improve backwashing effect, can prolong the running period after backwashing and ensures the water yield is objectively required.

Disclosure of Invention

The utility model aims to provide a backwashing system of a steel mill demineralized water ultrafiltration device, which is easy to control, can effectively improve backwashing effect, can prolong the running period after backwashing and ensures the water yield.

The utility model aims at realizing the method by comprising an ultrafiltration tank, a water inlet pipeline, a water outlet pipeline and a backwash pipeline, wherein the water inlet pipeline is communicated with a water inlet at the bottom of the ultrafiltration tank, the water outlet pipeline is communicated with a water outlet at the top of the ultrafiltration tank, the end part of the water outlet pipeline is connected with a clean water tank, the backwash pipeline comprises a backwash pipe, a gas wash pipe, a regulating pipe, an exhaust pipe and a blow-down pipe, one end of the backwash pipe is communicated with the clean water tank, the other end of the backwash pipe is communicated with the water outlet, a backwash pump and a backwash valve are arranged on the backwash pipe, one end of the gas wash pipe is communicated with the water inlet, the other end of the gas wash pipe is communicated with a compressed air storage tank, an air inlet valve is arranged on the gas wash pipe, the regulating pipe is arranged at the upper part of the ultrafiltration tank, the regulating valve is arranged on the regulating pipe, the exhaust pipe is arranged on the water outlet pipeline, the blow-down pipe is arranged at the bottom of the ultrafiltration tank, the blow-down pipe is provided with the blow-down valve, and the lower part in the ultrafiltration tank is provided with a turbidity sensor I.

The structure of backwash pipeline has been optimized to this device, the gas wash pipe and backwash pipe separately set up, the gas wash pipe sets up in the water inlet and goes out, the backwash pipe sets up in delivery port department, when needs wash the milipore filter, utilize the gas wash pipe to clean the milipore filter earlier, utilize compressed air to clean the effect of friction interference to the milipore filter, let the debris that adsorbs on the membrane become flexible drift, thereby create the condition for the water conservancy backwash, after the gas wash is accomplished, adopt the backwash pipe to backwash the milipore filter again, be favorable to improving the effect of backwash like this, simultaneously the governing pipe and the blast pipe that set up can prevent the milipore filter in gas wash and the washing in-process to hold down the pressure, guarantee that the gas wash pressure in the milipore filter is stable, make the effect of backwash better thoroughly under the condition that consumes equal compressed air. Compared with the structure of the prior air-water mixed backwashing, the device has the advantages that: the process of air washing and water washing is easy to control, the backwashing effect is improved, the running period after backwashing can be prolonged to 40 minutes from 30 minutes before, the water yield after backwashing is improved by 10% on the basis of the original structure, the backwashing device has good popularization and utilization values, and the popularization and the use are easy.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the present utility model;

in the figure: 1-ultrafiltration tank, 2-clean water tank, 3-backwash pipe, 31-backwash pump, 32-backwash valve, 4-gas wash pipe, 41-intake valve, 5-regulator pipe, 51-regulator valve, 6-exhaust pipe, 61-exhaust valve, 7-blowdown pipe, 71-blowdown valve, 8-compressed air storage tank, 9-turbidity sensor I, 10-inlet pipe, 101-feedwater pump, 102-inlet valve, 103-first flow sensor, 11-first bypass pipe, 111-first bypass valve, 12-venturi mixer, 13-outlet pipe, 131-turbidity sensor II, 132-second flow sensor, 133-outlet valve, 14-second bypass pipe, 141-second bypass valve, 15-level gauge, 16-clean water pipe, 161-clean water valve, 17-ultrafiltration membrane module, 18-inlet distribution disk, 19-inlet distribution pipe, 20-third bypass pipe, 201-third blowdown valve.

Description of the embodiments

The utility model is further described below with reference to the accompanying drawings, without limiting the utility model in any way, and any alterations or modifications based on the teachings of the utility model are within the scope of the utility model.

As shown in figure 1, the utility model comprises an ultrafiltration tank 1, a water inlet pipeline, a water outlet pipeline and a backwash pipeline, wherein the water inlet pipeline is communicated with a water inlet at the bottom of the ultrafiltration tank 1, the water outlet pipeline is communicated with a water outlet at the top of the ultrafiltration tank 1, the end part of the water outlet pipeline is connected with a clean water tank 2, the clean water tank 2 is used for storing clean water purified by the ultrafiltration tank 1, the backwash pipeline comprises a backwash pipe 3, a gas wash pipe 4, an adjusting pipe 5, an exhaust pipe 6 and a sewage draining pipe 7, one end of the backwash pipe 3 is communicated with the clean water tank 2, the other end of the backwash pipe is communicated with the water outlet, a backwash pump 31 and a backwash valve 32 are arranged on the backwash pipe 3, one end of the gas wash pipe 4 is communicated with the water inlet, and the other end of the gas wash pipe is communicated with a compressed air storage tank 8, the air-wash pipe 4 is provided with the air inlet valve 41, the adjusting pipe 5 is arranged on the upper portion of the ultrafiltration tank 1, the adjusting valve 51 is arranged on the adjusting pipe 5, the exhaust pipe 6 is arranged on the water outlet pipeline, the exhaust valve 61 is arranged on the exhaust pipe 6, the blow-down pipe 7 is arranged on the bottom of the ultrafiltration tank 1, the blow-down pipe 7 is provided with the blow-down valve 71, the lower portion in the ultrafiltration tank 1 is provided with the turbidity sensor I9, the turbidity sensor I9 is a structure used in the prior art, a finished product can be purchased in the market directly, and the turbidity sensor I9 mainly plays a role in judging the pollution degree of the ultrafiltration tank 1 by measuring the pollution degree of water.

Further, the water inlet pipeline comprises a water inlet pipe 10, a water feeding pump 101, a water inlet valve 102 and a first flow sensor 103 which are sequentially arranged on the water inlet pipe 10, the water feeding pump and the water inlet valve can convey desalted water into the ultrafiltration tank, the first flow sensor is of a structure used in the prior art, and the water inflow of the desalted water into the ultrafiltration tank can be timely monitored.

Further, the water outlet pipeline comprises a water outlet pipe 13, and a turbidity sensor II 131, a second flow sensor 132 and a water outlet valve 133 which are sequentially arranged on the water outlet pipe 13, wherein the air outlet pipe 6 is arranged on the water outlet pipe 13 close to one side of the water outlet, the turbidity sensor II 131 and the second flow sensor 132 are of structures used in the prior art, the turbidity sensor II 131 is used for detecting the pollution degree of purified water discharged from the water outlet pipe, and the set second flow sensor 132 is used for monitoring the purified water output of the water outlet pipe untimely.

When the turbidity sensor I9 detects that the turbidity degree of the desalted water in the ultrafiltration tank 1 reaches a set value, and the ultrafiltration tank 1 needs to be backwashed, the operation steps of the backwashed are as follows:

step one: firstly, closing a water supply pump 101 and a water inlet valve 102 on the water inlet pipe 10, closing a water outlet valve 122 on the water outlet pipe 13 after 3 seconds of time delay, and simultaneously closing a regulating valve 51 on the regulating pipe 5 to prevent the pressure in the ultrafiltration tank 1 from being suppressed;

step two: then, the regulating valve 51 and the exhaust valve 61 are opened, the air inlet valve 41 on the air washing pipe 4 is slowly opened, compressed air in the compressed air storage tank 8 is led into the ultrafiltration tank 1 through the air washing pipe 4, the ultrafiltration tank 1 is scrubbed for 4 minutes by the compressed air, impurities adsorbed on a membrane are loosened and drifted by the action of the compressed air on the scrubbing friction interference of the ultrafiltration tank 1, thus creating conditions for hydraulic backwashing, and after scrubbing is completed, the air inlet valve 41 is closed and then the exhaust valve 61 is closed;

step three: opening a backwash pump 31 and a backwash valve 32 on a backwash pipe 3, returning purified water in a purified water tank 2 to the ultrafiltration tank 1 through the backwash pipe 3, backwashing the purified water, and discharging water after backwashing for 30 seconds through an adjusting pipe 5;

step 4: closing the regulating valve 51, opening the blow-off valve 71, continuously introducing clean water into the ultrafiltration tank 1 through the backwash pipe 3 for backwash, and discharging water after backwashing for 30 seconds through the blow-off pipe 7;

step 5: after backwashing is finished, the backwashing pump 31 and the backwashing valve 32 are closed, the sewage discharging valve 71 is closed after 3 seconds, the water inlet valve 102 and the water feeding pump 101 are opened, and the water purifying working state is entered;

the structure of backwash pipeline has been optimized to this device, the air wash pipe 4 and backwash pipe 3 separately set up, air wash pipe 4 sets up in the water inlet and goes out, backwash pipe 3 sets up in delivery port department, when needs wash ultra-filtration jar 1, utilize air wash pipe 4 to clean ultra-filtration jar 1 earlier, utilize compressed air to clean the effect of friction interference to ultra-filtration jar 1, let the debris that adsorbs on the membrane become flexible drift, thereby for the hydraulic backwash condition creation, after the air wash is accomplished, back wash is carried out to ultra-filtration jar 1 to backwash pipe 3 again, be favorable to improving the effect of backwash like this, simultaneously regulation pipe 5 and blast pipe 6 that set up can prevent that ultra-filtration jar 1 from holding down the pressure at air wash and water wash in-process, guarantee that the air wash pressure in the ultra-filtration jar 1 is stable, make the effect of backwash better thoroughly under the condition that consumes equal compressed air volume.

Preferably, in order to further improve the air scrubbing effect of the compressed air, a first bypass pipe 11 is arranged on the water inlet pipe 10 between the water inlet valve 102 and the water inlet, the first bypass pipe 11 is communicated with the air scrubbing pipe 4, a first bypass valve 111 is arranged on the first bypass pipe 11, a venturi mixer 12 is arranged on the air scrubbing pipe 4 close to the water inlet, the first bypass pipe 11 can be opened when necessary in the process of conveying the compressed air into the ultrafiltration tank 1 by the air scrubbing pipe 4, a certain amount of desalted water is conveyed into the venturi mixer 12 by the first bypass pipe 11, after the desalted water and the compressed air are mixed in the venturi mixer 1, the desalted water and the compressed air are sprayed into the ultrafiltration tank 1, so that the pressure and the humidity of the air inlet can be improved, and the air scrubbing effect can be improved.

Preferably, a second bypass pipe 14 is installed on the water outlet pipe 13 between the second flow sensor 132 and the water outlet valve 133, the second bypass pipe 14 is communicated with the sewage drain pipe 7, a second bypass valve 141 is installed on the second bypass pipe 14, when the turbidity sensor II 131 monitors that the pollution degree of the purified water in the water outlet pipe 13 reaches a set value, the water outlet valve 133 can be closed, the second bypass valve 141 is opened, and unqualified purified water is discharged into the sewage drain pipe 7 through the second bypass pipe 14 for subsequent treatment.

Further, the top of the clean water tank 2 is provided with a liquid level meter 15, the clean water tank 2 is provided with a clean water pipe 16, the clean water pipe 16 is provided with a clean water valve 161, the liquid level meter 15 is of a structure used in the prior art and is mainly used for monitoring the water level in the clean water tank 22, and when the water level exceeds the highest water level, the clean water valve 161 can be opened to discharge clean water in the clean water tank 2 through the clean water pipe 16.

Further, the ultrafiltration tank 1 internally mounted has a plurality of milipore filter subassemblies 17, milipore filter subassemblies 17 are the structure that prior art used, milipore filter subassemblies 17 include parts such as support, milipore filter subassemblies 17, the governing pipe 5 is installed in the upside of milipore filter subassemblies 17, turbidity sensor I9 installs in the downside of milipore filter subassemblies 17, and in milipore filter subassemblies 17 downside's milipore filter subassemblies 1, be provided with into water distributor and can carry out even distribution with the demineralized water of inlet tube 10 import, so also be favorable to improving the effect of purifying, preferably, it includes the many water distribution pipes 19 of water distribution dish 18 to advance, water distribution dish 18 communicates with the water inlet, the vertical installation of many water distribution pipes 19 is on the upper surface of water distribution dish 18, and many water distribution pipes 19 extend to the clearance between a plurality of milipore filter subassemblies 17, the upper end of water distribution pipe 19 is sealed, be provided with a plurality of distribution holes on the pipe wall of water distribution pipe 19, water distributor can carry out even distribution to entering into brine tank 1 in the time of even distribution, can carry out even distribution to the compressed air distribution's of water distributor and even distribution, further the compressed air is scrubbed with the air of the further area of the ultrafiltration membrane 17, further improves the effect of scrubbing.

Preferably, a third communicating pipe 20 is installed between the water inlet pipe 10 and the sewage draining pipe 7, a third communicating valve 201 is installed on the third communicating pipe 20, and in the process of backwashing, the backwashed water may be guided into the water inlet distributor through the water inlet distributing pipe 19, at this time, the third communicating valve 301 is opened, and the water guided into the water inlet distributor is discharged through the third communicating pipe 20.

Claims (9)

1. The utility model provides a steel mill demineralized water ultrafiltration device backwash system, includes milipore filter (1), water inlet pipeline, water outlet pipeline and backwash pipeline, its characterized in that: the utility model provides a water inlet intercommunication of intake pipe and milipore filter (1) bottom, the delivery port intercommunication at outlet pipe and milipore filter (1) top, the end connection of outlet pipe has clean water tank (2), backwash pipe includes backwash pipe (3), gas wash pipe (4), governing pipe (5), blast pipe (6) and blow off pipe (7), the one end and the clean water tank (2) intercommunication of backwash pipe (3), the other end and delivery port intercommunication, install backwash pump (31) and backwash valve (32) on backwash pipe (3), the one end and the water inlet intercommunication of gas wash pipe (4), the other end and compressed air storage tank (8) intercommunication, install admission valve (41) on gas wash pipe (4), the upper portion at milipore filter (1) is installed in governing pipe (5), install governing valve (51) on blast pipe (6) on the outlet pipe, install discharge valve (61) on blast pipe (6), blow off pipe (7) are installed in the bottom of milipore filter (1), install on blow off pipe (7) and install in milipore filter (1) under ultra-filtration portion (I) sensor (9).

2. The steel mill desalinated water ultrafiltration device backwash system of claim 1, wherein: the water inlet pipeline comprises a water inlet pipe (10), and a water feeding pump (101), a water inlet valve (102) and a first flow sensor (103) which are sequentially arranged on the water inlet pipe (10).

3. The steel mill desalinated water ultrafiltration device backwash system of claim 2, wherein: a first bypass pipe (11) is arranged on the water inlet pipe (10) between the water inlet valve (102) and the water inlet, the first bypass pipe (11) is communicated with the air washing pipe (4), a first bypass valve (111) is arranged on the first bypass pipe (11), and a venturi mixer (12) is arranged on the air washing pipe (4) close to the water inlet.

4. The steel mill desalinated water ultrafiltration device backwash system of claim 1, wherein: the water outlet pipeline comprises a water outlet pipe (13), and a turbidity sensor II (131), a second flow sensor (132) and a water outlet valve (133) which are sequentially arranged on the water outlet pipe (13), and the exhaust pipe (6) is arranged on the water outlet pipe (13) close to one side of the water outlet.

5. The steel mill desalinated water ultrafiltration device backwash system of claim 4, wherein: a second bypass pipe (14) is arranged on the water outlet pipe (13) between the second flow sensor (132) and the water outlet valve (133), the second bypass pipe (14) is communicated with the sewage draining pipe (7), and a second bypass valve (141) is arranged on the second bypass pipe (14).

6. The steel mill desalinated water ultrafiltration device backwash system of claim 1, wherein: the top of water purification tank (2) is installed liquid level gauge (15), be provided with water purification pipe (16) on water purification tank (2), install water purification valve (161) on water purification pipe (16).

7. The steel mill desalinated water ultrafiltration device backwash system of claim 1, wherein: the ultrafiltration tank is characterized in that a plurality of ultrafiltration membrane assemblies (17) are arranged in the ultrafiltration tank (1), the regulating pipe (5) is arranged on the upper side of the ultrafiltration membrane assemblies (17), the turbidity sensor I (9) is arranged on the lower side of the ultrafiltration membrane assemblies (17), and a water inlet distributor is arranged in the ultrafiltration tank (1) on the lower side of the ultrafiltration membrane assemblies (17).

8. The steel mill desalinated water ultrafiltration device backwash system of claim 7, wherein: the water inlet distributor comprises a water inlet distribution disc (18) and a plurality of water inlet distribution pipes (19), wherein the water inlet distribution disc (18) is communicated with a water inlet, the water inlet distribution pipes (19) are vertically arranged on the upper surface of the water inlet distribution disc (18), the water inlet distribution pipes (19) extend into gaps between the ultrafiltration membrane components (17), the upper ends of the water inlet distribution pipes (19) are sealed, and a plurality of distribution holes are formed in the pipe wall of the water inlet distribution pipes (19).

9. The steel mill desalinated water ultrafiltration device backwash system of claim 2, wherein: a third communicating pipe (20) is arranged between the water inlet pipe (10) and the sewage draining pipe (7), and a third communicating valve (201) is arranged on the third communicating pipe (20).