SK279755B6 - Filling body, in particular for biological bodies in waste water purification plants, cooling towers and the like - Google Patents

Abstract

A filling body has vertically arranged channels (2) with open ends (3) through which liquid and gas mixtures flow. The intermediate (central) portion (4) of the channels (2) has a constant or substantially constant cross-section. Portions (5, 6, 7, 8) having a variable cross-section are linked at the top and bottom of the intermediate portions (4).

Description

BACKGROUND OF THE INVENTION The present invention relates to a filled body having channels for the flow of a mixture of liquids and gases and which can be used in particular as a biological burner, a solid biofilm treatment unit, a biological filter for sewage treatment plants, a cooling tower filler and the like.

BACKGROUND OF THE INVENTION

A method is known which relates to waste water treatment containing organic impurities, biological waste water treatment using a solid biological film.

In both cases, the biomass bound to the surface of the body below the surface of the process water is an active member of the system. The bur body may be made of a material with a large specific surface area, mesh or building elements with perpendicularly arranged channels.

The biofilm formed on the surface of the body must - in the case of an aerobic system - be supplied with oxygen. This is done by blowing air or technical oxygen under the normal body. The gas bubbles flow up in the ducts of the body and, during their stay, exert a turbulent flow around them, causing the gas to dissolve more efficiently, and the movement of water having a richer oxygen content in the ducts is more intense. All this leads to a more intensive gas exchange between the biofilm and the liquid, and thus a better functioning of the system is guaranteed. These aerobic systems are referred to as solid biofilm contactoxidation systems.

At the same time, other biological wastewater treatment systems are known, such as dispersion sludge settlers or systems for living sludge processes operating with two kinds of sludge, the other purifying the wastewater with sludge having the character of a solid biofilm formed on the surface of the contact sludge. elements and a floating dispersion sludge.

Contact elements, built-in or embedded in the system, are generally referred to as fillers (as fillers). The filler must meet more requirements. It must have a large specific surface area, be suitable for adhering biofilm, and have channels supporting the flow and turbulent movement of water. The channel cross-section is best when the emerging gas bubbles induce a rapid flow of water and at the same time, due to the large local concentration difference, there is a rapid and efficient gas exchange between the liquid and the channel wall causing turbulent liquid flow. In the case of an aerobic system, flow serves to more efficiently exchange gas between bubbles and liquid. These requirements are in part contradictory. Increasing the specific surface area relative to the surface of the filter body (characteristic values of m ² / m ³ ) is an important requirement in order to increase the total area of the biological film, but reducing the cross-section of the channels is limited by the disadvantageous slowing of the liquid-gas flow.

Further, there is a requirement that the filler material be chemically stable, its structure light, its surface suitable for biofilm adherence, cost-effective manufacture and simple assembly. These requirements are most easily met with fillers made of plastic.

Many contact elements made of plastics are known which, however, only partially meet the above requirements.

According to the German patent specification reg. no. DE 2 901 509 has a zigzag contact element. A disadvantage of this embodiment is that the gas bubble driving force (the so-called mammoth pump effect) is only applied to a small extent, the dispersion mixture can flow only with a large loss of flow through the contact element and the required turbulence can only be ensured using auxiliary energy.

Also known are fillers having perpendicular channels with a circular cross-section. The outer cylindrical casing of the tubes, however, does not form any active surface, so that with respect to film formation the effective surface is only about 40 to 60% of the total surface.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a filler for biological wastewater treatment plants, cooling towers and the like which removes the above-mentioned shortcomings of today's filler bodies for similar applications, can be manufactured using simple manufacturing technology, has a large specific surface and supports gas exchange more effective than the present solutions of embodiments of these filler bodies.

The invention is based on the discovery that in perpendicularly arranged channels for a liquid-gas flow mixture, the contact between the liquid and the material forming the channel wall as well as the liquid and gas is particularly strong and the gas exchange is particularly intense when varying pressure and flow ratios develop. . This can be achieved by having the channels between them which have a substantially constant cross-section to which the variable-cross section plates are attached. According to another observation, the most economical shape of the body can be achieved in such a way that the channels have a variable cross section and a wall having only a small thickness is arranged between the individual channels.

The invention is based on the further discovery that a filler body having variable cross-sectional channels can be realized most economically by making the flat and zigzag-shaped plates by vacuum molding the plastic plates, joining the plates together to form the channels described and preferably are fixed by gluing.

Based on this knowledge, the task was solved according to the invention by means of a filler, which can be used in particular for biological bodies of sewage treatment plants, cooling towers and similar devices having open channels at their ends arranged to flow a liquid-gas mixture which they are arranged perpendicularly, the essence of which is that the intermediate section of its channels has a constant or substantially constant cross-section and a variable cross section is connected to this intermediate section at the bottom and at the top.

Advantageously, the sections having a tapering and expanding variable cross-section of adjacent channel sections of the filler body have an increasing and decreasing cross-section with each other, as well as when the channel cross-section has a hexagonal shape; generally, the channel cross-section is an equilateral or substantially equilateral purpose serving a hexagon.

According to another feature of the invention, the cross-sectional area is between 1.0 and 15.0 cm ² , furthermore the ratio of the length of the opposite section with constant cross-section of the channels and the length of any section with variable cross section is between 1: 4 and 4: 1. virtually any practical task of contacting a liquid with a gas can solve it.

SK 279755-6

Advantageously, the walls of the channels of the filler body are further formed by means of profile plates, when the plates forming the channels are fixed non-movably to one another, preferably glued.

In general, the channel walls consist of thermoplastic plastics, preferably PVC, and the filler bodies can of course also be made of other materials.

It may happen that the padding body is formed from a single block, and the padding bodies are generally made up of several blocks. Generally, the height of the filler body is less than 1 m, its weight is less than 50 kg.

Finally, it is preferred that the channels produced preferably by vacuum forming are bounded by mutually connected and preferably glued fastened profile plates.

Overview of the figures in the drawing

The invention is further described with reference to the accompanying drawings, which show one preferred embodiment of a filling element. In the drawings: FIG. 1 shows a part of an exemplary embodiment of a filler according to the invention in a perpendicular section along the line M-M in FIG. 2, FIG. 2 is a plan view of a portion of the padding body of FIG. 1 along line B-B of FIG. 1, FIG. 3 shows a cross-section along line A-A in FIG. 1, FIG. 4 is a top detail of the padding body of FIG. 1 to 3, shown in an axonometric view.

DETAILED DESCRIPTION OF THE INVENTION

For easier understanding of the drawings, FIG. 1, 2 and 3, respectively, one channel emphasized by parallel or cross-hatching and edges not lying in the cutting plane are shown by dashed lines.

In FIG. 1 to 3, it is possible to see in a perpendicular section three mutually parallel, open at their ends channels 2 of the highlighted part of the filling body. FIG. it is clear that the intermediate section 4 of the channels 2 has a constant or substantially constant cross-section to which is further connected a section 5 or 6 having an equally variable cross-section and upwards a section 7 or 8 equally with a variable cross-section.

In FIG. 1 to 3, a channel has been cross-hatched to which an intermediate (middle) section 4, with a constant or substantially constant cross-section, a downwardly connecting section 5 with a variable cross-section is formed upwardly narrowing (outwardly extending outwardly) and upwardly connecting section 8 with variable cross-section expands upwards (i.e. outwards).

In FIG. 1 to 3, a channel has been designated by parallel hatching to which the intermediate / middle section 4 with a constant or substantially constant cross-section, the downwardly connecting variable section 6 extends upwards (narrows outwardly) and the upwardly connecting variable section 7 the cross-section narrows upward (i.e. outwardly). In the embodiment shown in FIG. 1 to 3, the variable cross-section sections 5 and 6 connecting to the intermediate (central) section 4 with a constant or substantially constant cross-section at the bottom are formed complementary to each other upwardly tapering and widening upwardly, the upper sections 7 and 8 having a variable cross section have complementary embodiments tapering upwards and widening upwards.

Fig. 4 shows an axonometric view in the direction of the upper end seen from the upper part of the filler body according to FIG. 1 to 3, wherein the open upper end 3 of the channels 2 can be seen. The bounding walls between the variable cross-section sections 7 narrowing upwards and the variable cross-section sections 8 widening upwards have been denoted 9.

From the comparison of FIG. 1, 2, 3 and 4, it can be recognized that only the wall 9 of the channels 2 lies between adjacent channels 2 and the intermediate (middle) section 4 of the channels 2 joins downwardly the variable section 5 with the cross section and the variable section 6 having an upwardly extending and tapering cross-section as well as an intermediate (middle) section 4 of the channels 2, an upwardly connecting upwardly tapering variable cross-section having a section 7 and an upward section 8 having a variable the cross-sections have complementary widening and tapering cross-sections.

In the example of FIG. 2 and 3, the cross-sectional shape of the intermediate sections 4, the sections 5 and 7 tapering upwardly and having a variable cross-section, as well as the sections 6 and 8 upwardly spreading, and having a variable cross-sectional area of the hexagonal ducts 2.

An advantage of the filler according to the invention is that its specific surface area (m ² / m ³ ), based on its volume, allows the establishment and adherence of a large biological lawn (film), alternating constant and variable cross-sectional flow channel sections induced flow of liquid-gas mixture (the effect of mammoth pumps) variable pressure ratios, bubble chamber sizes, flow rate ratios, channel dimensions and bubble size of turbulent gas flow in which more gas dissolves, aerobic biological turf settles on channel surfaces on the other hand, better oxygen supply.

The contact element according to the invention was used for the biological pre-treatment of very heavily contaminated waste water coming from an industrial meat processing plant before entering the public canal. The plant capacity was 2000 m ³ / day; its organic load 4000 -

- 6000 kg / day BSB ₅ (biological oxygen demand) / day; the organic matter concentration of the raw waste water to be treated was 3000-4000 mg / l CSB _cr (chemical oxygen demand).

Industrial waste water, heavily contaminated, mechanically and flotation pre-treated to be treated, was introduced into two sequentially aerated tanks (bioreactors). In two tanks a total of 300 m ^{3 of} contact element made of plastic according to the invention was arranged below the waste water level. The specific surface of the contact elements was 200 m ² / m ³ , the length of the channel openings varied between 24 mm and 12 mm. Air from 3000 to 4000 m ³ / h was introduced into the contact elements from below. By means of the biofilm formed on the contact elements and the strong, intense turbulence of the air flowing through the channels of the contact elements, an extremely good biological cleaning effect could be achieved in said bioreactor. The parameters of the treated waste water were as follows: content of organic substances after treatment -100 mg / l CSB _cr

- 1 mg / l NH ₄

- 10 mg / l N.

These parameters correspond to the following degree of purification effect

-95 -98% BSB ₅

- 96% CSB _cr

- 95 - 98% NH ₄ -90 N.

In another case of use, the contact element according to the invention was used for the overall treatment of municipal waste water. The plant capacity was 1000 m ³ / day and the organic concentration was 300-500 mg / l KOI.

Purified, heavily contaminated waste water was introduced into the bioreactor after mechanical pretreatment. A total of 200 m ³ of contact elements (as described) were arranged in the tank below the waste water level. 300 m ³ / h air was introduced from below into the contact elements.

The biofilm formed on the plastic contact elements and the severe, intense turbulence reduced the organic matter content of the waste water to 8 mg / l BSB ₅ and 50 mg / l CSB _cr ; these values correspond to a degree of purification of about 90%.

The effects of the filler according to the invention will save the use of artificial recirculation devices or mixing devices. The filler body according to the invention can be produced economically from simple means and from cost-effective materials and its assembly can also be carried out simply and quickly.

The invention is in no way limited to the details described. The forms of protection are defined in the claims.

PATENT CLAIMS

Claims (13)

A padding element, in particular for biological wastewater treatment plants, cooling towers and the like, having channels for the flow of a liquid-gas mixture arranged perpendicularly and open at their ends, characterized in that the intermediate (central) section ( 4) the channels (2) have a constant or almost constant cross-section, and the intermediate sections (4) are connected at the bottom and at the top with sections (5, 6, 7, 8) having a variable cross-section. A padding body according to claim 1, characterized in that the sections (5, 6, 7, 8) having a tapering and expanding variable cross section of adjacent channels (2) have mutually widening and tapering cross sections. A padding body according to claim 1 or 2, characterized in that the cross-sectional shape of the channels (2) is hexagonal. A padding body according to claim 3, characterized in that the cross-section of the channels (2) is an equilateral or nearly equilateral, preferably hexagonal profile. Padding element according to one of Claims 1 to 4, characterized in that the cross-sectional area of the channels (2) is in the range of 1.0 to 15.0 cm ² . Padding element according to one of Claims 1 to 5, characterized in that the ratio of the length of the intermediate (4) having a constant cross-section and each section (5, 6, 7, 8) having a variable cross-section of the channels (2) is ranging from 1: 4 to 4: 1. Filling element according to one of Claims 5 or 6, characterized in that the walls (9) of the channels (2) consist of shaped plates. A padding body according to claim 7, characterized in that the plates forming the channels (2) are fixed non-slidably, preferably glued together. Filling element according to one of Claims 1 to 8, characterized in that the walls (9) of the channels (2) are made of thermoplastic, preferably PVC. A padding body according to any one of claims 1 to 9, characterized in that it consists of one block. Padding element according to one of Claims 1 to 9, characterized in that it also comprises a plurality of blocks. Padding body according to one of Claims 1 to 12 11, characterized in that its height is less than 1 m and its weight is less than 50 kg. A padding body according to any one of claims 1 to 13 12, characterized in that the channels (2) are bounded by shaped sheets, preferably made by vacuum forming and joined together, preferably glued together.