DE202004005736U1 - Filter for treating industrial waste water, comprises low pressure pumps, a storage vessel with a heat exchanger, a prefilter, and ultrafiltration modules - Google Patents

Abstract

A filter arrangement (100) for treating industrial waste water, esp for treating water containing tensides, comprises low pressure pumps (15,6), a storage vessel (3) with a heat exchanger (4), a prefilter (2) and ultrafiltration modules (7) for separating fibres, inorganic solids and micro-organisms. The vessel heat exchanger is used to warm the water to at least 60[deg]C which is the optimum temperature for inhibiting germs.

Description

The invention relates to a device or plant for the treatment of industrial and commercial waste water, in particular for the treatment of laundry wastewater containing tensides by micro- or ultrafiltration at elevated Temperatures of at least 60 ° C and others specially tailored to the respective system configuration Operating parameters. The separation takes place by means of a filter device (Membrane separation device), the medium to be filtered (raw waste water) into a concentrate / retentate enriched with foreign substances and is separated into a depleted filtrate / permeate.

Devices of this type are known. Known membrane separation devices according to the prior art exist essentially from the process stages pretreatment by wastewater equalization and Lint separation, microfiltration or ultrafiltration.

Treatment of surfactants wastewater extends according to the prior art according to the following scheme. The one in the washing process resulting waste water are about a pre-filter unit for separating lint into a compensation and stacking containers guided. Here takes place through constant stir an equalization of the differently loaded partial flows instead. Usually it cools Waste water here due to its dwell time before it enters the module cycle is fed.

However, there is a risk that by a possible Biofouling the plant runtime is very limited. Particularly The case of washing water treatment are favorable conditions for growth given by microorganisms. Carbon sources such as fats, proteins, carbohydrates and other organic soiling of the laundry form a suitable one Nutrient basis for microorganisms. Furthermore, temperatures are around 40 ° C and a pH of around 10 within the tolerance range of most microorganism species entered in the process. Contamination of the wash water to be treated with bacteria and Mushrooms of all kinds happen because of the soiled laundry this inevitably comes into contact with microorganisms in the environment. To counteract the problem of biofouling in washing water filtration In known systems, the medium to be filtered is usually chemicals added. A possibility is, for example, microbial growth with antibiotics that added to the wash water to counteract and the microorganisms kill. The addition of antibiotics in the wash water is very low Concentrations are effective but very cost-intensive. The technical solution the biofouling problem by optimizing the filtration parameters is therefore the most effective.

It is therefore the task of the present Invention to provide a device of the type mentioned in the introduction, which is made possible by various system components explained in more detail below, an effective and affordable Wash water treatment.

This problem is solved with those in the protection claims listed Features resolved.

According to the invention, that is in the reservoir - dirty water there is a heating element. This is necessary for (hot) filtration at higher Temperatures - at least 60 ° C. A hot filtration is cheap in that since the filtrate flow due to the lower density / viscosity compared to the wash solution increases at ambient temperature. A major advantage of filtration at elevated Temperature is also due to membrane fouling microbial growth is effectively prevented. In contrast to The state of the art in the invention is such that the ultra- or microfiltration stage discharges microbially unpolluted waste water. It there is therefore no risk of contamination of the following Washing processes. It is usually the case with state-of-the-art systems so that after the actual reprocessing there is still a sterilization step is arranged, this is not applicable here for the reasons mentioned.

Even with constant and almost optimal Operating conditions and product data, dead microorganisms are stored and dirt particles on the membrane surface. It therefore happens a decrease in permeate output. For this reason, membrane regenerations at regular intervals during the entire operation necessary to remove particle deposits from the membrane surface. These membrane regenerations are carried out in plants according to the state of the art Technology mostly ignored, causing it to sink the filtrate output comes after a short system runtime. The The principle applied to the membrane regeneration is the backflow of filtrate counterflow or "back flush" closed permeate outlet valve a small amount of permeate the dimensioned membrane surface integrated in the filtration system Volume-related Backwash tank, suddenly pressed through the membrane into the retentate space. Due to this pressure surge The top layer formed is lifted from the membrane along the entire length of the module and from the cross flow due to the high overflow speed carried away and evenly in the Retentate distributed. A large Advantage of the "back flush "device is that cleaning the entire module takes only a few seconds takes. Since backwashing in Possible intervals of a few minutes are, a high layer thickness of the inevitably formed Top layer can be prevented.

This backwashing at periodic intervals, combined with the hot filtration of the wastewater, ensures high permeate output over a long period of time.

Backwashing counteracts the deposition of organic and inorganic materials on the membrane, but cannot completely prevent it. A covering layer builds up during the operating time of the system. In the case of hard water, there is also the danger that, when passing through the membranes, hydrogen carbonates will convert to poorly soluble carbonates with the simultaneous formation of CO ₂ . The resulting carbonates settle in the pores (scaling). The CO ₂ formed during the decomposition of the bicarbonates leads to an additional blocking of pores by gas bubbles.

The consequence of all these processes is a continuous decrease in the permeate flow. The cleaning cycle then applied is rinsing the membranes with acid and base. The acid dissolves the carbonates, but thereby forms CO ₂ bubbles. The base dissolves the CO ₂ and thus the gas bubbles. For this purpose, according to the invention, a CIP cleaning device is provided which feeds the chemicals into the system in an optimal, previously determined, concentration.

According to an advantageous and compact Design of the invention, the plant design is modular. Consequently it can be expanded as required and can be adapted to any capacity become. The facility is for the stationary Use for the treatment of industrial and commercial waste water, in particular for the treatment of wastewater containing surfactants. she serves recovery of water and possibly unused surfactants from the raw sewage. The system is a single-stage membrane filtration system.

• 1. Vorfiltration,
• 2. Auffangen des vorfiltrierten Abwassers in einem Vorlagebehälter,
• 3. Aufheizen des Abwassers im Vorlagebehälter,
• 4. Filtration des Abwassers durch die Filtereinrichtung,

The following technological sequence is given for the treatment of the waste water with the device according to the invention:

• 1. prefiltration,
• 2. collecting the pre-filtered wastewater in a storage container,
• 3. heating of the wastewater in the storage tank,
• 4. Filtration of the waste water through the filter device,

The penetration of those in the sewage A pre-filter unit prevents fluff in the system or largely restricted. For the Ultra- or microfiltration, the wastewater is freely selectable and over one Thermostat adjustable temperature heated.

In the subsequent cross-flow filtration will all be unresolved and dispersed contaminants are separated from the wastewater. That filtered Water is stored in a collection tank downstream of the system and is available for further use in the respective process.

The washing water treatment plant is designed to remove the following water constituents or can be significantly reduced:

• – Flusen und anorganische Feststoffe,
• – Mehrzellige Mikroorganismen und deren Sporen,
• – Algen, Bakterien und größere Viren.

Solids larger than a defined diameter:

• - lint and inorganic solids,
• - multicellular microorganisms and their spores,
• - Algae, bacteria and larger viruses.

The control panel - the control unit - the filter device is designed so that all system parameters are clearly arranged and are easy to grasp. In addition to the displays about the operating parameters in the front panel of the control cabinet also the switching elements for the control of the filtration process.

A feed pump feeds the material to be filtered Wash water from the storage tank into the cross - flow cycle on. At high transfer speeds and thus high filtrate flows To achieve this, the wash water is pumped through a cross-flow pump Membrane filter modules pumped.

The pumps (feed pump, cross-flow pump) are multi-stage inline low pressure centrifugal pumps advancement thinner, non-explosive media. The pumps are suitable for delivery of pure water, process water and water Solutions, Detergents, suspensions and other media of the same density or toughness like water without abrasive or long-fiber components. The pumps are self-priming for liquid Media.

The membrane filter modules are cylindrical Stainless steel case for each 7 membranes. Ceramic membranes are preferably used, where on the extruded support body the membrane on the inside of the tubes is sintered. Filtration on the membrane surfaces all undissolved components, such as microorganisms, solids of all kinds or colloids.

For flow measurement are preferred magnetic - inductive Flow meter used. The transmitter is directly on the Flow sensor installed.

Draw inductive flow meters themselves through their insensitivity across from solid components.

• 1. den / die Rohwasserspeicher und
• 2. den / die Produktwasserspeicher

wiedergegeben wird.Pressure sensors are used to measure the level in the containers. These sensors generate a current signal, which is used by an evaluation unit as a fill level for:

• 1. the raw water storage (s) and
• 2. the product water tank (s)

is played.

• – Anlagendruck auf der Rohwasserseite vor Membranmodul(en);
• – Anlagendruck auf der Rohwasserseite hinter Membranmodul(en);
• – Anlagendruck auf der Produktwasserseite, Rückspüldruck;
• – Luftdruck;

Standard and contact manometers are used to check the system pressure. The contact pressure gauges for the system pressure and for the air pressure switch off the system in the event of malfunctions. The pressure gauges are standard pressure gauges that give the system operator additional information about the condition of the filter units. The pressure gauges show the following pressures:

• - Plant pressure on the raw water side in front of the membrane module (s);
• - Plant pressure on the raw water side behind membrane module (s);
• - system pressure on the product water side, backwash pressure;
• - air pressure;

To control the process temperature is in the flow direction a resistance thermometer is installed directly in front of the membrane modules.

The fully automatic control of the Device is made via a PLC control module. All signals from measurement and control technology are processed here. The temporal processes are integrated in the program.

The sampling points are for sampling of samples for optical or analytical evaluation. The sampling taps are made of stainless steel and have a plastic handle for better usability. This provides thermal protection when taking hot samples.

Other characteristics result from the following description of an embodiment.

embodiment

1 shows a device according to the invention with all system components and peripheral system components, the device being designed as a system with two modules and 7 membranes each.

In the figure is a filter device 100 for the treatment of industrial and commercial wastewater, in particular for the treatment of wastewater containing surfactants. The actual micro or ultrafiltration system is a corrosion-resistant storage container 3 with a pre-filter unit for separating lint and coarse dirt particles 2 upstream. There is a heat exchanger in the reservoir 4 which can be operated both electrically and via the superheated steam in the laundry. This heat exchanger is necessary to heat the waste water to be filtered to the optimal process temperature of at least 60 ° C. The heat exchanger is made of corrosion-resistant 1.4301 stainless steel.

The system is charged by means of a multi-stage, self-priming inline low-pressure centrifugal pump 6 for the conveyance of thin, non-explosive media. The wastewater is supplied using stainless steel pipes. There is a non-return valve in front of the pump 5 arranged which prevents the backflow of the medium to be filtered into the storage container. The pipes are connected to the pump 6 flanged. In the exemplary embodiment shown, the recycling system contains two cylindrical filter modules 7 , These are designed as stainless steel cylinders. The cylinders are made of corrosion-resistant stainless steel 1.4301, they are welded, straightened and highly polished. On both cylinders there is an outlet for filtrate / permeate 8th and a pressure measuring point. In order to achieve high overflow speeds and thus high permeate flows, the heated wastewater is pumped using the cross - flow pump 15 pumped over the modules. This is a multi-stage, self-priming inline low-pressure centrifugal pump.

The resulting filtrate is first fed through the filtrate outlets into the two volume-dependent passages - stainless steel - backwash tank installed in the system, which are sized for the membrane surface 9 guided. These are cylindrical and made of stainless steel 1.4301. They serve to temporarily store a defined amount of filtrate, which is used for backwashing (blasting off the membrane coatings). The system is a collecting tank for storing the filtrate 11 beige sets.

Appropriate devices are provided on the system for the sample name 19 . 20 , The sampling taps are made of stainless steel and have a plastic handle for better usability, which provides thermal protection when taking hot samples.

Pneumatic diaphragm valves are used as shut-off devices 10 used. These are operated with the compressed air that is always available in the laundries.

The compressed air is present at the system and is initially controlled by a pressure reducer 18 headed to reduce air pressure. The existing compressed air is also required to remove a defined volume of permeate from the backwash tanks during backwashing 9 to push through the membranes in the opposite direction to the filtration. A solenoid valve is used to clean the membranes 13 and a check valve 14 necessary. The solenoid valve 13 is required to inject the Reini supply solution. The built-in check valve 14 serves to shut off or release the cleaning agent.

Claims (9)

filtering device 100 , for the treatment of industrial and commercial wastewater, in particular for the treatment of wastewater containing surfactants, characterized in that effective micro- or ultrafiltration at elevated temperatures is made possible by the arrangement of low-pressure pumps 15 and 6 over one in front of the storage container 3 with heat exchanger 4 arranged prefilter unit 2 and ultrafiltration modules 7 to separate fibers and fluff, inorganic solids, single and multicellular microorganisms and their spores, algae and larger viruses. Filter device according to claim 1, characterized in that in the storage container 3 a heat exchanger 4 , for heating the wastewater to the optimal filtration and germ inhibition temperature of at least 60 ° C, is arranged. Filter device according to claim 1 and 2, characterized in that for charging the system and the cross-flow circuit (feed pump, circulation pump) multi-stage inline low-pressure centrifugal pumps 15 and 6 can be used to convey low-viscosity, non-explosive media. Filter device according to claim 1, 2 and 3, characterized in that cylindrical filter modules for micro- or ultrafiltration 7 are used, in which ceramic membranes are preferably used. Filter device according to claim 1 to 4, characterized in that the membrane-sized, volume-dependent backwashing tank 9 Pass-through backwash tanks are in which the resulting permeate is temporarily stored. Filter device according to claim 1 to 5, characterized in that the temporarily stored permeate for backwashing under claim 5 from the volume-dependent backwashing containers dimensioned by the membrane surface 9 with the help of compressed air against the direction of filtration through the membranes. Filter device according to claim 1 to 6, characterized in that to carry out the cleaning of the membranes no extensions and conversions are necessary on the system and cleaning with the elements integrated in the system 13 and 14 can take place. Filter device according to claim 1 to 7, characterized in that the derived permeate in a collecting tank 11 is saved. Filter device according to claim 1 to 8, characterized in that corresponding shut-off devices for the sample name on the system 19 . 20 are provided. The shut-off devices are made of corrosion-resistant material and have a plastic handle for better usability, which provides thermal protection when taking hot samples.