DE3807748A1 - MULTILAYER POROESE FUEL CONSTRUCTION, ESPECIALLY FOR THE SEPARATION OF LIQUID AND SOLID PHASES - Google Patents

Abstract

A multilayer porous structure, particularly for the separation of liquid and solid phases and/or dispersing liquid or gas, especially for the treatment of waste water and sludges. The structure comprises at least one supporting layer and at least one active layer this latter consisting of chemically inactive inorganic granular material and binding material, the pore size of the active layer being smaller than that of the supporting layer. At least on the surface of the grains constituting the active layer there is provided a hydrophobic binding material formed by silicone resin and/or bisphenol-A based epoxy resin. The regenerating of the structure can be carried out by merely flushing its surface.

Description

The invention relates to a multilayer, porous filter or / and dispersion structure, whose at least one layer by glued solid granules is formed. The single ones porous layers are also through each other Gluing together. The porous filter according to the invention and / or dispersing microstructure in the same way for the separation of fixed and liquid phases and for dispersing gases in Liquids or liquids in other liquids or gases. The microstructure according to the invention can be beneficial in the field of wastewater treatment or in general the water treatment be used.

In the course of water purification become - under other - filtering operations performed; it there is a biological degradation of organic matter; Occasionally, the aggressive gases are expelled from the liquids or a supply of gases in the same, furthermore a drainage (dehydration) of sewage sludge. With the help of the invention Filtrierkonstruktion can handle these tasks Become: in a part of the cases becomes solid phase-containing Liquid led to the filtration structure, which filters out the solid phase; in the other part of the Cases - in the course of dispersion in the form of fine bubbles - gas through the structural structure supplied to the liquid mass.  

To solve the filtration and (sludge) dewatering tasks different methods are known:
Eg sand filtration; filtration through rigid filter plates; Filtration made by glued gravel filters, textile or metal sieves, as well as on-machine filtration (centrifugal and vacuum filtration, sludge pressing, etc.). The classic method of sludge dewatering is dehydration.

The efficiency of the known machine Filtration and drainage methods is cheap, their Filtration technology applicability but relatively closely, being their use in drainage technologies through their specifically high investment and operating costs is limited.

For this reason, in the sewage treatment predominantly on the use of natural Substance-based filtering technologies applied, of which the sand filtration the most widespread is.

In the sand filters, the material grain size increases in the direction of the liquid flow to. From the through the sand filter flowing wastewater adds the Solid phase in the sand layer, wherein the liquid phase flows through it. It follows that the filter layer clogged and only so again can be made operational, that one filtered out Solid phase removed by a countercurrent purge or degrades the clogged layers and new ones replaced.  

From US Pat. Nos. 4,452,698 and 43 81 998 are rigid, made of multilayer filter plates existing filter constructions recognizable. These made of granular material by gluing Filter constructions consist of a base layer and a filter layer. The base layer itself is course also liquid permeable, however their pores are larger than the pores of the filter plates. The granules are made of inorganic substances, it will be z. B. Al₂O₃-, corundum, silicon carbide, boron carbide and similar granules for making the filters used. These filters have a relative account-consuming construction on.

The US Patent No. 43 82 863 relates to one of the similar ones described above Construction, but contains three layers and is in their preparation also costly.

According to the description of the number 216/83 published Hungarian patent application are used to reduce the groundwater pressure z. B. For drainage of basements a homogeneous structure having used (single layer) glued gravel filters.

The drying out of the mud is one of the most problematic phases of wastewater treatment. The sludge drying plants have a large Space requirements and their mode of operation is largely of depending on the climatic conditions, so that the drainage the mud takes a long time and the extraction of the dry sludge requires - because  the need for appropriate protection of the drainage system - manual work. The others Use of the manually extracted sludge is prevented by its gravel content.

In the course of the (waste) water treatment Gas-liquid systems on the one hand in the Removing the gases in the liquid with the help of others in the liquid Gases, on the other hand, in biological purification in Course of the use of gases in appearance. On Example of the first-mentioned application is the expulsion of the aggressive CO₂ gas by air bubbles, for the latter case, dispersing from air or oxygen into the fluid mass Securing the living conditions of the liquid phase located microorganisms. From the to Solution of these tasks can be applied technologies made with the help of nozzles deep blowing of Air are considered to be the most effective in which, however the circumstance a problem means that the uniform Gas supply can not be guaranteed. A difficulty also causes the circumstance that usually a discontinuous gas supply is required and during breaks the solid phase in the liquid causes a blockage can cause the nozzles.

The object of the invention is to provide a filter and / or dispersing construction to provide the Filtration with maximum efficiency, you Operation only a minimal cost and energy expenditure requires, is insensitive to constipation and in  capable of distributing the gas evenly to supply the liquid.

The invention is based on the knowledge if the filter granules are hydrophobic Adhesive united to a filter layer get that on the surface of the filter construction the grains located there covering the adhesive skin in the course of the filtering process a with the electric charge of the material to be filtered present solid granules have the same sign having electric charge, whereby they are in the Solid particles to be filtered Good material particles repels. That way, in the field the hydrophobic adhesive coating containing on the surface of the filter granules layer effective force field emerge, a celebration of the in the product to be filtered granules on the Surface of the filter construction prevented. Instead develops out of these granules above the Filter construction a natural filter cake, the with the filter construction in no immediate Touch stands. Consequently, the cleaning of the Filters only a surface rinse, since the solid state contamination do not penetrate into the interior of the filter and its pores can clog. basis The invention is further the realization that the Resin coating on the surface as well prevents that in the course of biological Cleaning or to expel the harmful gases applied ventilation following that with the liquid Surface in contact with solids and / or Settle microorganisms and - the nozzle-like functioning -  Clog pores. This way will a more effective biological cleaning or gas injection possible.

Because of these findings, the Asked task in the context of the invention with the help solved a multilayer porous structure structure, the at least one support layer and at least one over smaller openings than the base layer having (smaller pore sizes) active Layer contains and at least the active layer from chemically inactive inorganic granular substances - Conveniently silicate-based - for example of basalt, zeolite, Al₂O₃ granules and binder (s) exists, with the essential feature of the filter construction It is that at least on the surface the granule forming the active layer a hydrophobic properties-containing binder made of silicone resin and / or epoxy resin on bisphenol A Base is provided.

The invention is accordingly a multilayered porous structure for the separation of Solid-liquid systems or for dispersion of gas-liquid systems, in particular for treatment and purification of wastewater or sewage sludge, the at least from a generally upper thinner active layer and a generally lower stronger one Support layer is made, each of which is porous, but where the pores of the active layer are smaller than those of the Support layer are and at least their active layer from a chemically inactive inorganic material, conveniently made from granules of materials  Silicate industry, preferably basalt, zeolite, Al₂O₃ and similar substances, and of binder (s) and characterized in that at least on the surface of the active layer forming Filter granules a strong hydrophobic properties exhibiting Binder is provided, which is made of silicone resin and / or bisphenol A based epoxy resin consists.

It is therefore considered by a "generally" spoken upper and a "generally" lower layer, because the filter construction not only in horizontal Position (eg for gravitational filtration) installed, but also arranged in a vertical position can be.

The silicone resins are expediently Resin types of siloxane units with functionality 1 . , , 4 and / or by the condensation of Monomers of functionality 1. , , 3 manufactured products Branched structure selected, so that advantageously Phenylmethyl polysiloxane and / or phenyl methyl polysiloxane-polyester and / or phenyl-methyl vinyl siloxane (polymerized with H₂O₂) can use.

As epoxy resin is suitably z. For example, a bisphenol-A based resin made from 4,4'-dihydroxydiphenylpropane and epichlorohydrin having a molecular weight between 380-38,000, its epoxy equivalent between 175-4,000, its ester equivalent between 80-200, a having functional group, its viscosity molecular 5-150 P (at 20 ° C), and its specific gravity between 1.14 to 1.2 ^- 17 OH. The formula is:

The filter construction will be convenient designed so that the active layer has a strength from 5-15 mm, the base layer has a thickness of 50-150 mm is.

While in contact with liquid coming surface of the porous filter and / or Dispersierkonstruktion to build a more effective force field the arrangement of relatively small pores seems expedient, it is expedient that Filter resistance in the opposite direction to diminish and so on in contact with the liquid coming surface opposite side provide larger pores, even one - expediently perforated - steel plate or other Metal construction possibly plastic construction z. As an aluminum or plastic mesh the role of the wearer can take.

The hydrophobic and the electric force field producing resin also sticks to the Filter granules together and guaranteed on this Make a constant pore size.

In accordance with the foregoing have according to another feature of the invention the active layer (layers) forming granule dimensions  from 0.2-1 mm, the pores of the layer (layers) the dimensions of 0.1-1 mm.

It is also advantageous if - how has already been referred to above - the Supporting layer of the porous filter according to the invention and / or dispersing construction by perforated Steel plates or others made of metal or plastic manufactured openwork constructions, eg. B. Aluminum or plastic mesh or other existing inorganic granules and binders Layers is formed, with the size of the granules 1-5 mm, the pore size 0.8-1.2 mm, advantageously about 1 mm. In general, the Strength of the active layer / layers 5-15 mm, the strength the base layer / base layers 50-150 mm.

The porous construction can also look more than two layers are built, z. B. so that the two upper layers of inorganic Filter granules and binder, the lower however, from a perforated steel plate or a other openwork made of metal or plastic Plate, z. As an aluminum or plastic grid. However, the filter construction can also be designed in this way be that the support layer by a mechanical Attachment, z. B. Probation is reinforced.

Another embodiment of the invention porous construction is characterized that it is composed of three layers, of which at least one outer active layer and a intermediate layer of inorganic material granules  and binder.

Both the active area and the Surface of the base layer may be one from the plane deviating geometry z. B. a pipe, cone, hemisphere etc. shape.

In one with the filter construction according to the invention Filtration performed in their course on the surface of the active layer - which works as a filter surface - a stronger one Solid phase (eg, sludge) arise, however not stuck on this. Just for that reason The sludge can be removed mechanically and the filter be regenerated by rinsing off its surface.

The multilayer porous according to the invention Structure construction is not only suitable for filtering, but also for dispersing gases in liquids. In this case, the desired Gas supplied from the carrier layer ago and the former filter surface is considered an active dispersant (Atomizer) work. It is special in this case expedient, this surface one of to give the plane different geometry. By the By the way, fine pores of the active surface can be one assured fine distribution of the injected gas and also prevents that on the liquid side Surface hydrophobic properties having binder, the z. In the case a discontinuous operation of the microorganisms z. B. Fito and monoplankton organisms (eg algae) settle and clog your pores. To this  Way, the construction is permanently operational.

The invention will be further explained below described in detail by examples:

Example 1

For filtration of municipal sewage sludge is calculated on an area of 1 m² the Filter construction according to the invention produced as follows:

active filter layer
- Material (aluminum oxide Al₂O₃)
- structure:

Size (FEPA standard) Quantity (kg) 22 10.4 36 0.60 70 0.60

- Binder: Epoxy resin adhesive (TIPOX IHS) 1,22 Kg
- Layer thickness: 5 mm
Permeability coefficient of the active filter plate K = 2.1 × 10 ^-3 cm / s;
Void content n 2 32%
base course
- Material: pearl gravel
- Grain size: 3-7 mm
- Binder: Epoxy resin adhesive (TIPOX IHS) 2.25 kg
- Thickness: 45 mm
- Mass: 90.0 Kg

The initial dry content of the municipal Sewage sludge was 2.0% (its moisture content accordingly 98.0%). As a conditioner was a  4% solution of the drug "Zetag 57" used. The Dry content of the dewatered sludge was 38%. It became a pure, filter-free filtrate receive. FEPA is a particle size standard international standard, the Hungarian standard MSZ 6506-84 corresponds.

The one component of the epoxy resin adhesive "TIPOX IHS" is a modified with a reactive diluent Bisphenol-alpha-diglycidyl ether epoxy resin, the other component is an aliphatic polyamine mixture (Manufacturer: "Tiszamenti Vegyimüvek" Tiszaszederk'ny, Hungary).

The preparation "Zetag 57" is a polyacrylamide-based polyelectrolyte, a product of the "Alleid Colloid" GmbH, Hamburg, Germany).

example 2

Sewage sludge from a leather factory was filtered with the filter construction according to the invention, which for an area of 1 m² is composed as follows has been:

active filter layer
- Material: silicon carbide (SIC)
- grain structure

Size (FEPA standard) Quantity (kg) 22 10.40 36 0.60 70 0.60

- Binder: Silicone resin adhesive (VP 2261) 1.35 Kg
- Thickness: 5 mm

The active filter plate was over 3 Heat treated at a temperature of 150 ° C hours. The permeability coefficient and the void volume were similar to those in Example 1;

- Supporting layer: same as described in Example 1

The initial dry content of sewage sludge the leather factory was 1.5% (the moisture content accordingly 98.5%). As a conditioner In this case, a 4 ‰ solution of the preparation was also used Used "Zetag 57". The chromium content of the wastewater was 100 mg / liter. As a result of filtering became a dewatered mud with a dry content of 30% and a deodorant-free filtrate with one Chromium content of 0.05 mg / liter.

The silicone resin adhesive "VP 2261" is the Product of the company "Wacker Chemie" Munich, Germany.

example 3

Oil-containing sewage sludge was treated with the in Example 1 filter structure filtered. The initial dry content of the sludge was 2%, its moisture content is 98%, as a conditioner was a 4% solution of the drug "Zetag 57" used. As a result of filtration became a dehydrated Mud with a dry content of 33% and a feedable into the general sewerage network Received quality having filtrate.

In the case of all three examples was for regeneration  the surface of the active layer of the Filter plate only a rinse the surface required.

The filter resistance in the individual Layers also changed after a longer one Operating time by no means, a flushing (backwashing) was not required.

example 4

Of the above-described filter constructions, air was dispersed in water using the construction set forth in Example 2. In a construction with a surface of 1 m², the air transport was 20 m³ / h, the amount of oxygen 100 g / O₂ / h; the energy consumption gross 0.6 kW / 1000 g O₂; the average bubble size d = 2.5 mm.

The biggest advantage of the invention exists in that for the regeneration of the construction no Rinse, only temporarily rinsing off his Surface is required, its energy and time and the amount of human labor insignificant is. The construction is simple, their usability extraordinarily versatile.

The invention is of course limited by no means to those described in detail above Examples, but may be within the claims defined scope of protection in many ways become.

Claims (9)

1. Multilayer porous microstructure construction for the separation of liquid and solid phases and / or dispersion of liquids or gases, in particular for the treatment of wastewaters and sewage sludges having at least one base layer and at least one opening having smaller dimensions than the base layer (having smaller pore sizes) contains active layer and at least the active layer of chemically inactive inorganic granular materials - expediently based on silicate - z. B. of basalt, zeolite, Al₂O₃ granules and binder (s), characterized in that at least on the surface of the active layer forming granules hydrophobic properties exhibiting binder of silicone resin and / or epoxy resin on bisphenol-A- Base is provided. 2. Microstructure according to claim 1, characterized characterized in that the binders from siloxane units of functionality 1. , , 4 built resin types and / or by the condensation of monomers of functionality 1. , , 3 produced, branched structure, expediently Phenyl-methyl-polysiloxane and / or phenyl-methyl- polysiloxane-polyester and / or - expediently polymerized with H₂O₂ - phenyl-methyl-vinyl-siloxane Resin types are. 3. microstructure according to claim 1, characterized in that  the hydrophobic properties having binder Epoxy resin which is one of 4,4'-dihydroxydiphenyl Propane and epichlorohydrin produced resin based on bisphenol A, its molecular weight 380-3800, epoxy equivalent 175-4000, ester equivalent 80-200; has a 4-17 OH functional group, its molecular viscosity 5-150 P (at 20 ° C); and its specific gravity is 1.14-1.2. 4. Structure construction according to one of the claims 1-3, characterized that the active layer / layers forming Granules a grain size of 0.2-1 mm, the pores the layer / layers have a size of 1.0-1 mm. 5. Microstructure construction according to one of the claims 1-4, characterized the base layer is perforated by steel plate (s) or one of inorganic granules and Binder existing layer is formed in the the size of the grains between 1-5 mm, the pore size between 0.8 and 1.2 mm, advantageously 1 mm. 6. Structure construction according to one of the claims 1-5, characterized that the thickness of the active layer / layers 5-15 mm, that of the base layer / base layers, however 50-150 mm. 7. Microstructure construction according to one of the claims 1-6, characterized  that they have a mechanical strength of Supporting layer-increasing construction, advantageously Contains concrete steel inserts. 8. Structure construction according to one of the claims 1-7, characterized that it's made up of three layers, of which at least one outer active layer as well an intermediate layer of inorganic granules of material and binder. 9. Structure construction according to one of the claims 1-8, characterized that the surface of the active layer and / or the support layer deviates from the plane, expediently Pipe, cone, hemisphere or candle shape having.