CN1491904A

CN1491904A - Film assembly cleaned mechanically

Info

Publication number: CN1491904A
Application number: CNA021459665A
Authority: CN
Inventors: 樊耀波; 徐慧芳
Original assignee: Research Center for Eco Environmental Sciences of CAS
Current assignee: Research Center for Eco Environmental Sciences of CAS
Priority date: 2002-10-25
Filing date: 2002-10-25
Publication date: 2004-04-28
Anticipated expiration: 2022-10-25
Also published as: CN1195575C

Abstract

The present invention belongs to the field of membrane bioreactor, and is especially one mechanically cleaned membrane assembly. The membrane assembly includes membrane plate, water outlet branched pipe and aeration pipe. The membrane plate consists of membrane filament, membrane brush and water collecting pipe; the parallel membrane filaments and membrane brushes are arranged alternately; the membrane filament has its two ends connected to upper and lower water collecting pipes separately with the drained water being collected via membrane filament to two water collecting pipes; the water outlet branched pipe has one end connected to the water collecting pipe and the other end to the general water outlet pipe; the aeration pipe is connected to the branch and general aeration pipe; and gas is generated on two sides of the aeration pipe below the membrane plate and raises along the sides of the membrane plate. The membrane assembly is used in treating waste water with high flux.

Description

The membrane module that adopts machinery to clean

Technical field

The invention belongs to field of membrane bioreactor, specially refer to a kind of membrane module that adopts machinery to clean.

Background technology

Known membrane bioreactor, film pollute and cause that energy consumption is higher, are one of problems that hinders the membrane bioreactor widespread use.Film pollutes by suspended substance, colloidalmaterial, larger molecular organics and stops up due to the fenestra at face deposition and small organic molecule, the film surface pollution thing is deposited on the film surface and forms settled layer, and then mud is deposited between the film silk, cause water stream channel to stop up, destroy the turbulent fluctuation state of current, weaken the cleanup action of flow shear to film, cause membrane flux to reduce rapidly, unit produces water consumption sharply to be increased.The split membrane bioreactor adopts increases the pollution that the circulating water flow flow velocity weakens settled layer; The submerged membrane bio-reactor adopts air-blowing to produce the air water stream of turbulent fluctuation state, its shear action in the film silk to reduce the thickness of settled layer.

According to the hydromechanics theory, fluid equals zero in the speed near the film surface, and it is extremely far away from the surface, flow velocity has the velocity slope [Yao-Bo Fan, Ju-Si Wang, the et al that progressively strengthen, Treatment of a Dying Wastewater from A Woolen Mill Using An A/OMembrane Bio-Reactor, Journal of EnvironmentalScience (China), 2000, Vol 12 (3): 344-488].No matter this that is to say how big it is that the speed (V-bar) of cross-flow has, always near having a fluid-flow rate to equal zero in the certain limit of film surface or being close to null detention layer.Exist the cake layer that can not wash away by cross-flow in this detention layer, this cake layer is called as frictional belt or film Pollution Boundary Layer.Simultaneously, depositing of film Pollution Boundary Layer easily forms the mud alluvial between the film silk.Because the existence in frictional belt, the pollution for the cake layer that prevents film must keep the speed of very big cross-flow, the required circular flow of cross-flow often tens times of permeable amount to hundred times.

Membrane module attracts each other between the film silk when big membrane flux easily in addition, forms film tow group, reduces the useful area of film greatly.

Detachable membrane bioreactor is by increasing the circulating water flow flow velocity, the submerged membrane bio-reactor increases the cross-flow flow velocity by increasing the air-blowing amount, though these methods have weakened the pollution in frictional belt, energy consumption is increased, the detachable membrane bioreactor energy consumption is usually at 2～12kWh/m ³, the submerged membrane bio-reactor, owing to do not need circulating water flow, energy consumption is lower than detachable membrane bioreactor, can drop to 0.3～0.6kWh/m ³, with traditional activated sludge process energy consumption 0.3～0.5kWh/m ³Compare approximate [Gu Guowei, He Yiliang, membrane bioreactor---research and application in sewage disposal, Beijing: Chemical Industry Press, 2002.5].

The film Pollution Boundary Layer is thicker, when membrane flux is difficult to maintain the level of less expensive, and the mode that adopts matting or machinery to clean usually, mechanical cleaning way commonly used is that cotton balls is cleaned the film surface.Though matting and machinery clean and can remove the film Pollution Boundary Layer well, but complicated operation, need emit the mud in the reactor or take out membrane module, so cleaning only occurs in, and the film Pollution Boundary Layer thickens, membrane flux has descended more for a long time, therefore, be difficult to solve the problem of film Pollution Boundary Layer.

Summary of the invention

The object of the present invention is to provide a kind of membrane module that adopts machinery to clean, between the film silk, especially the rubbing effect between film silk and the film brush reaches the effect that film silk machinery is cleaned, overcome the problem of film Pollution Boundary Layer, alleviate the film pollution level, prevent that simultaneously the film silk from forming bundle group, the useful area that keeps film, increase permeable amount, prolong the film cleaning interval, cut down the consumption of energy.

The membrane module that adopts machinery to clean of the present invention comprises diaphragm, exit branch and aeration tube; Described diaphragm is made up of film silk, film brush and header; Settle the film brush between the film silk at interval, the film brush is parallel with the film silk, and the length of film silk and film brush will maintain surplus, film silk and film brush are lax the arrangements, and certain radian is arranged, film silk and film brush jitter motion make film silk and film brush produce friction when relative movement during with the assurance air-blowing.Two ends of film silk are connected to two headers up and down, and water outlet sees through the film silk and combines in two headers.

Described exit branch one end is communicated with header, and the other end is communicated with outfall sewer, and outfall sewer can be connected with sleeve pipe by loose joint with exit branch.

Described aeration arm one end is communicated with aeration tube, and the other end is communicated with the aeration house steward; Aeration house steward and aeration arm can be by loose joints and telescopic joint; Described aeration tube is positioned at the diaphragm bottom, and gas is created in aeration tube and tiltedly descends both sides, and along rising on two sides of diaphragm-operated.

Described diaphragm can be a slice, two or multi-disc, and the multi-disc diaphragm constitutes a row diaphragm.Mounting distance was to produce friction and be as the criterion to guarantee that film silk on each diaphragm can collide to intersect mutually when the multi-disc diaphragm was settled, as shown in Figure 2; How much can assembling of film silk and film brush according to mechanical cleaning performance.

Described film silk is hollow fiber ultrafiltration membrane or microfiltration membrane etc.

Described film brush comprises various materials, as nylon or cotton etc.; The film brush can be various forms, as smooth surface or surface cilium etc. is arranged.

The principle of work of the present invention's machinery rinsing membrane module is: the aeration dispersion device is positioned at the diaphragm bottom, and a large amount of gases pass through diaphragm along the diaphragm both sides, form the water flow of a large amount of violent turbulent fluctuations at face.Water flow makes the mutual friction of two diaphragm-operated film silk phases, and make that relative movement produces friction between each diaphragm-operated film silk and the film brush, the friction that reaches between the film silk between film brush and the film silk makes pollutent be difficult to reduce film Pollution Boundary Layer thickness greatly at film silk surface deposition.Because the film brush is not subjected to the suction negative pressure to its attracted by surfaces and densification pollutent, the shake of film brush can be removed its surperficial pollutent effectively simultaneously, is difficult for forming mud alluvial passage between film silk and the clean film brush.Like this, membrane module of the present invention has just realized that the limit goes out the machinery that cleans the waterside and cleans, and has overcome the pollution of film Pollution Boundary Layer effectively and has prevented that the film useful area from reducing.

Membrane module of the present invention is made simple, can advise film production greatly; Utilize membrane module of the present invention to handle waste water, membrane flux can improve 10%～30%; The membrane bioreactor of being made up of mechanical rinsing membrane module of the present invention can be applicable to the processing of various waste water, as zymamsis waste water, petrochemical wastewater, wool spinning waste water, municipal effluent etc.

Description of drawings

Fig. 1. the front view of the present invention's machinery rinsing membrane module;

Fig. 2. the side-view of the present invention's machinery rinsing membrane module;

Fig. 3. adopt preferred embodiment 1 process flow sheet of mechanical rinsing membrane module.

Reference numeral

1. film silk 2. films are brushed 3. exit branch, 4. aeration arms

5. header 6. aeration tubes 7. loose joints 8. sleeve pipes

9. outfall sewer 10. aeration house stewards 11. diaphragms 12. membrane modules

13. bio-reactor 14,15,16. pumps 17. effluent troughs

Specific embodiments

In order to understand the present invention better, technical scheme of the present invention is described below in conjunction with drawings and Examples.

Embodiment 1.

See also Fig. 1 and Fig. 2.Membrane module 12 comprises diaphragm, exit branch and aeration tube.The placement of two diaphragms 11 is can collide intersection generation friction mutually with the film silk 1 that guarantees each diaphragm 11 to be as the criterion, and the film silk is a hollow fiber ultrafiltration membrane.Film silk 1 and film brush 2 have certain radian, film silk 1 and film brush 2 energy jitter motion when guaranteeing air-blowing, and the film brush is ganoid nylon.Spaced and parallel is placed film brush 2 between the film silk 1, and film silk 1 and film brush 2 has relative movement to produce friction during air-blowing.Two ends of film silk 1 are connected to two headers 5 up and down, and water outlet sees through film silk 1 and combines in two headers 5, and film silk 1, film brush 2 and header 5 are formed diaphragm 11.Outlet system comprises exit branch 3 and outfall sewer 9, exit branch one end is communicated with header, the other end is communicated with outfall sewer, and exit branch 3 is connected with sleeve pipe 8 by loose joint 7 with outfall sewer 9, and the filtered water in the header 5 finally obtains by outfall sewer 9.Aerating system comprises aeration house steward 10, aeration arm 4 and aeration tube 6.Described aeration arm one end is communicated with aeration tube, and the other end is communicated with the aeration house steward; Aeration house steward 10 is connected with loose joint 7 by sleeve pipe 8 with aeration arm 4, and aeration tube 6 is positioned at the diaphragm bottom, and the gas that always is in control by aeration is created in aeration tube 6 oblique both sides down, and along rising on two sides of diaphragm 11.

See also Fig. 3.Fig. 3 represents the application of the present invention's machinery rinsing membrane module 12 in water technology, comprises bio-reactor 13, mechanical rinsing membrane module, effluent trough 17, service pump 14, suction pump 16, air-blowing pump 15 and pipeline.Sewage to configuration is handled, and its COD is 1000～5000mg/L.Waste water is pumped in the anaerobic pond by service pump, and gravity flow enters in the bio-reactor, and the biodegradable material in the waste water is adsorbed, degrades by microorganism in reactor.The air-blowing pump has two effects by the air-blowing of aeration tube, and the one, for the microorganism in the reactor provides oxygen, the 2nd, the water flow that produces the turbulent fluctuation state washes away the film surface, prevents that film from polluting.Water outlet is pumped through the film silk by suction pump.COD is less than 50mg/L in its water outlet, and clearance is greater than 95%, and the membrane flux of unit membrane flux ratio normal film assembly improves 50-100%, and energy consumption also correspondingly reduces 10-30%.

Claims

1. a membrane module that adopts machinery to clean comprises diaphragm, exit branch, aeration arm and aeration tube; It is characterized in that:

Described diaphragm is made up of film silk, film brush and header; Settle the film brush between the film silk at interval, the film brush is parallel with the film silk; Two ends of film silk are connected to two headers up and down, and water outlet sees through the film silk and combines in two headers;

Described exit branch one end is communicated with header, and the other end is communicated with outfall sewer;

Described aeration arm one end is communicated with aeration tube, and the other end is communicated with the aeration house steward;

Described aeration tube is positioned at the diaphragm bottom.

2. membrane module as claimed in claim 1 is characterized in that: described film silk and film brush are lax the arrangements, and certain radian is arranged.

3. membrane module as claimed in claim 1 is characterized in that: described diaphragm is a slice, two or multi-disc, and the multi-disc diaphragm constitutes a row diaphragm.

4. membrane module as claimed in claim 3 is characterized in that: mounting distance was to produce friction and be as the criterion to guarantee that film silk on each diaphragm can collide to intersect mutually when described multi-disc diaphragm was settled.

5. membrane module as claimed in claim 1 or 2 is characterized in that: described film silk is hollow fiber ultrafiltration membrane or microfiltration membrane.

6. membrane module as claimed in claim 1 or 2 is characterized in that: described film brush is smooth surface or surperficial ciliate film brush.

7. membrane module as claimed in claim 6 is characterized in that: described film brush comprises nylon or cotton.