CN1695776A

CN1695776A - Method for rinsing membrane-filtering unit of hollow fiber

Info

Publication number: CN1695776A
Application number: CN 200510013249
Authority: CN
Inventors: 王志; 樊智锋; 解利昕; 王纪孝; 王世昌
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2005-03-28
Filing date: 2005-03-28
Publication date: 2005-11-16
Anticipated expiration: 2025-03-28
Also published as: CN1317056C

Abstract

A method for flushing the hollow fibre membrane filter features that when the flow and quality of the product of membrane module are lowered, a flushing pump is turned on to perform reverse flushing and the reverse flushing channel is then cut off the perform forward flushing. Said reverse fushing and forward flushing are alternatively performed until the flow is restored to normal value.

Description

The purging method of doughnut membrane-filtering unit

Technical field

The present invention relates to a kind of purging method of doughnut membrane-filtering unit, promptly supply with backwashing water by regular pulse mode, realize hydrodynamic cleaning efficiently, the cleaning on intact pair of films surface recovers film properties.

Background technology

In recent years, along with the successful exploitation of new membrane material and membrane process, membrane separation technique has been used to industrial production and wastewater treatments such as petrochemical industry, medicine, textile printing and dyeing, food, papermaking.Film all can be polluted in actual application, causes film to produce water flux and descends, and the cutoff performance variation of film can have influence on the normal use of film when serious.It is one of bottleneck that influences the membrane separation technique broader applications that film pollutes.Effectively cleaning method is to solve the important channel that film pollutes.

The cleaning method of film has physics to clean and Chemical cleaning usually.Chemical cleaning wherein is to add certain suitable chemical agent in current, continuous wash cycles, and this method can be removed compound dirt, recovers membrane flux rapidly.The difficult point of chemical cleaning method is to need to select suitable cleaning agent, particularly for the system of complicated component, selects very difficulty of cleaning agent, and this method also can produce the cleaning waste liquid simultaneously.It is the fluid-mixing flushing membrane surface that utilizes the water or the empty G﹠W of high flow rate that physics cleans.Common physics cleaning method has the low pressure high flow rate to clean and backwash.Conventional back-washing method is that the backwash stream is set in the membrane module purging system, starts this stream during backwash the membrane module continuous water feeding is cleaned.This cleaning method exists cleaning efficiency to hang down and problems such as water consumption is big.Above-mentioned cleaning method cleaning performance all is subjected to the restriction of condition own, under many circumstances, can not efficiently solve the membrane pollution problem in the film use.

Summary of the invention

The object of the present invention is to provide a kind of purging method of doughnut membrane-filtering unit, this method flushing process water consumption is few, flush efficiency height, thereby the service life of having improved film device effectively.

The present invention is realized that by following technical proposals described doughnut membrane-filtering unit comprises hollow fiber film assembly; What be connected with membrane module comprises what receiver and feed pump were formed, to the membrane module feeding device; The product receiving system and the flusher that comprise compositions such as product storage tank or clear water jar and flushing water pump that are connected with membrane module.

This device is implemented the central purging method of operation, it is characterized in that comprising following process:

1, when the product flow of membrane module and quality have obvious reduction, stop to the membrane-filtering unit feed, start the scavenging pump in the flusher, carry out backwash by the products export end water inlet of membrane module and with pulsating flow, flushing water is by the discharging of the sewage draining exit up and down in the device;

2, cut off the backwash stream then, with constant flow rate membrane module is just washed, flushing water is sent into hollow fiber film assembly charging port via feed pump, washes away behind the film surface by last sewage draining exit discharging;

3, above-mentioned steps 1 backwash and step 2 are just being washed mutually and are being hocketed, till the flux of hollow-fibre membrane recovers.

Above-mentioned each backwash process generally comprises the water inlet of 3～4 subpulses, each pulsation water inlet cycle time was 30～90 seconds, the pulsation flow of inlet water equates or does not wait that the intermittent time was 5～10 seconds, and this intermittent time, washing intakes to finished flush discharge process required time in order to stop; Just washing process time was 40～60 seconds at every turn.

The invention has the advantages that, adopt pulse mode to supply with flushing water, the impact of flushing water to the film silk strengthened in the cooperation of step such as rely on water inlet, emptying and leave standstill, and helps the vibration of film silk self, thereby can effectively remove the pollutant on film surface; Adopt pulse mode to supply with flushing water, can strengthen the intensity of hydrodynamic cleaning, improve flush efficiency as much as possible, reduce the wash water amount, effectively prolong the service life of film, strengthen the economy of this process.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Among the figure 1 be material-storage jar, 2 for feed pump, 3 for the charging valve, 4 for down blow mouth valve, 5 for the down blow mouth, 6 be hollow fiber film assembly, 7 for last sewage draining exit valve, 8 for last sewage draining exit, 9 for the return valve door, 10 for the products export valve, 11 for clean inlet valve, 12 clean the water inlet control valves, 13 for flushing water pump, 14 be product jar or clear water jar.

Fig. 2 is pulse water-feeding flow changing curve in the flushing process of the present invention's employing;

The specific embodiment

The invention provides a kind of cleaning method of doughnut membrane-filtering unit.In specific embodiment, used hollow fiber film assembly is four cun a polyvinylidene fluoride microporous filtering film assembly, the charging of doughnut membrane-filtering unit is the sewer of circulation cooling tower, after the processing through the micro-filtration membrane device, can hold back most suspended substances in the waste water, colloid, algae and other microorganisms, product water is as clear as crystal can do middle water reuse.What the backwash in this Industrial Wastewater Treatment process was adopted is the pulse water-supply scheme, and as shown in Figure 2, backwashing water wherein is the product water of micro-filtration membrane device, describes the present invention below in detail and utilizes pulse to supply with the method that flushing water carries out the film cleaning.

Through the operation of certain hour, the product water-based of micro-filtration membrane can descend, and need clean.At first carry out backwash according to the present invention,

closure valve

3,10 is opened valve 4,7,11, by the flow and the pressure of control valve 12 control backwash water inlets.Backwash water enters membrane module by the products export end on hollow fiber microfiltration membrane assembly 6 tops, and the back flush film is discharged by last sewage draining exit 8 and down blow mouth 5.In the backwash process of film, according to the mode intermittent entry backwash water in the accompanying drawing 2, promptly the backwash water yield remains on 20L/min in preceding 40 seconds, 5 seconds then, close flushing water pump 13 and valve 11, stop the backwash water inlet, flushing water in the emptying membrane module 6, leave standstill hollow-fibre membrane, open flushing water pump 13 and valve 11 then, continued into backwash water 40 seconds, close flushing water pump 13 and valve 11 again, emptying was left standstill 5 seconds, opened flushing water pump 13 and valve 11 at last again, supplied with backwash water 40 seconds.By pulse water-feeding, emptying so clocklike and leave standstill, can make backwash water that the pollutant of face is produced bigger impact, the film silk is effectively shaken, cause the pollutant of face to come off.

After above-mentioned backwash operation is finished, carry out the positive flushing operation of film.Generally, flushing water just adopts the feed liquid of storage tank 1.Open valve 3,7, closure valve 4,10,11.Flushing liquor enters in the hollow fiber film assembly 6 via feed pump 2 from material-storage jar 1, positive flushing water flow keeps being stabilized in 30L/min, flushing water can effectively wash away the film surface, take away the film surface pollution thing that above-mentioned backwash operation stays, the cleaning of intact pair of films, recover membrane flux, then by last sewage draining exit 8 emptyings.

By hocketing of above-mentioned backwash and positive flushing operation, observe water and the backwash effluent quality situation of just flushing out, when the pollutant load in the water was few, the stopper film cleaning operation resumed production, backwash and just washing each flux is restored in the present embodiment.Experimental result shows, adopts method of the present invention that film device is washed, and than the service life that the method for continuous supply flushing water has improved film, can improve 3～5 times the service life of film.

Claims

1, a kind of purging method of doughnut membrane-filtering unit, described doughnut membrane-filtering unit comprises: hollow fiber film assembly; The membrane module feeding device that comprises receiver and feed pump composition that is connected with membrane module; The product receiving system and the flusher that comprise product storage tank and flushing water pump composition that are connected with membrane module are implemented the central purging method of operation to this device, it is characterized in that comprising following process:

(1) when the product flow of membrane module and quality have obvious reduction, stop to the membrane-filtering unit feed, start the scavenging pump in the flusher, carry out backwash by the products export end water inlet of membrane module and with pulsating flow, flushing water is by the discharging of the sewage draining exit up and down in the device;

(2) cut off the backwash stream then, with constant flow rate membrane module is just washed, flushing water is sent into hollow fiber film assembly charging port via feed pump, washes away behind the film surface by last sewage draining exit discharging;

(3) the positive flushing operation of step (1) backwash and step (2) hockets mutually, till the flux of hollow-fibre membrane recovers.

2, the purging method of doughnut membrane-filtering unit according to claim 1 is characterized in that:

Each backwash process generally comprises the water inlet of 3～4 subpulses, each pulsation water inlet cycle time was 30～90 seconds, the pulsation flow of inlet water equates or does not wait that the intermittent time was 5～10 seconds, and this intermittent time, washing intakes to finished flush discharge process required time in order to stop; Just washing process time was 40～60 seconds at every turn.