WO1999002237A1

WO1999002237A1 - Method and device for separating materials and guiding device therefor

Info

Publication number: WO1999002237A1
Application number: PCT/EP1998/004201
Authority: WO
Inventors: Dieter Frankenberger
Original assignee: Dieter Frankenberger
Priority date: 1997-07-11
Filing date: 1998-07-07
Publication date: 1999-01-21
Also published as: EP0998341A1; CA2295692A1; DE19729802C2; DE19729802A1

Abstract

The invention provides for a method and device for separating solid mineral grain materials, such as sand, from organic materials, suspended mateterials, easily or hardly soluble materials contained in a liquid-solid mix, for instance a mix from waste water purification plants. According to said method, the liquid-solid mix is tangentially introduced into a vessel (1), at an inlet port (13). Said liquid-solid mix flows towards an outlet port (16), in said vessel (1), at a sufficiently low rate so that when flowing said heavy components from liquid-solid mix, that is essentially solid mineral grain materials, settle forming a sediment bed (22). Said components forming sediment bed are removed and optionally dehydrated. The method according to the invention is characterized in that said liquid-solid mix is forcibly conveyed, in order to flow in a spiral fashion, between the inlet port (13) and the outlet port (16), at least through a partial deep area.

Description

Method and device for separating substances and

Guide for this

Technical field

The invention relates to a method for separating granular mineral solids such as sand from organic matter, suspended matter, slightly and sparingly soluble substances in a liquid-solid mixture, for example a mixture from wastewater treatment plants, in which the liquid-solid mixture is tangential at a radially external inlet point is introduced into a container. In the container, the liquid-solid mixture flows from the inlet point to a radially inner outlet point at such a low speed that the heavy mixture constituents, essentially the granular mineral solids, of the liquid-solid mixture sink to form a sediment bed. The sunken components of the sediment bed are then discharged and, if necessary, dewatered. Furthermore, the invention relates to a completely new guide device for improving the method mentioned. The invention also relates to a device for separating granular, mineral solids, such as sand, from organic substances. Suspended substances, easily and poorly soluble substances in a liquid-solid mixture, such as a mixture of wastewater treatment plants, which contain a container for the

Liquid-solid mixture and to form a sediment bed from substantially sedimented solid particles. Furthermore, a correspondingly designed, radially external inlet point is provided for the tangential introduction of the liquid-solid mixture into the container. In addition, there is a radially internal discharge point on the device for the discharge of the excess liquid and the suspended matter therein, the organic matter and the like.

The method and the device are particularly intended for separating the sand in a solid-water mixture from organic substances, suspended substances, easily and slightly soluble substances which are carried along therein and, if appropriate, by an additionally introduced washing medium, for example water , Air or an air-water mixture. That means, in particular, the invention relates to sand traps or sand washing plants or their working methods, in which the sand from sewage treatment plants and street sweepers is separated from putrefactive organic substances. State of the art

A device for separating floating substances and suspended matter from a liquid is known for example from DE 195 01 034 AI. In a container there is an essentially vertically extending closed partition wall, the upper area of which projects above the liquid level and is open or at least permeable in its lower area. From Fig. 3 of this document it can be seen that this vertical partition has a circular cross-section, at which a liquid with the floating and sinking substances is introduced tangentially.

Circular sand traps or sand classifiers or heel basins in circular construction, in which the basins are fed centrally, are disclosed, for example, in DE 43 18 522 AI. The centric loading of these known devices has the disadvantage that flow losses occur which are to be avoided due to the flow direction directed from the inside to the outside.

A general method and a device for separating solids from a suspension is known from DE 43 12 540 Cl. Here there is a tangential introduction on the outside of the container and a central discharge. It is pointed out that the flow to the center of the clarification chamber is essentially spiral, but this is essentially achieved in that the flow is caused by fluidic means before entering the clarification chamber and is moved in a spiral path to the center in the clarification chamber. Due to cross flow losses, this device is not optimal with regard to the possible degree of separation. A procedure and a device of the type mentioned are known from DE 44 10 969 Cl. The device described here is used to separate easily soluble substances, suspended substances and poorly soluble substances from a solid or liquid-solid mixture and comprises a washing and separating container and a motor-driven, obliquely upward-facing, which adjoins the deep region of the washing and separating container a screw conveyor device with a discharge helix for discharging the separated mineral solids. In addition, a drain device for discharging the liquid is created at the upper edge of the container. An inlet opening for introducing a washing liquid is arranged in the deep region of the washing and separating container. A drain device is used for the discharge of the washed-out, easily soluble substances, suspended substances and poorly soluble substances. It is also vertically spaced from the deep region of the washing and separating container and extends essentially vertically within the same.

This device known from this is indeed well suited for the separation or separation of the granular mineral solids in general, in particular the sand in the waste water. However, it has been found that the possible efficiency of a device of the type mentioned, in particular a sand trap or a sand washing system, has not yet been fully exploited in the current design. Presentation of the invention

The invention is based on the technical problem of increasing the efficiency of a procedure or a corresponding device explained at the outset, and a

To provide structural element with which existing devices can be retrofitted for this purpose without great effort.

This technical problem is solved by a procedure with the

Features of claim 1 solved. In addition, a control device with the features of claim 6 is provided to solve the technical problem. Finally, the technical problem underlying the invention is solved by a device with the features of claims 11 and 19, respectively.

The invention is based on the idea that the flow forming during the introduction of the liquid-solid mixture between a radially outer inlet point and a radially inner outlet point is forced to run in a spiral manner, so that the degree of excretion is increased, which is due to an extension of the travel distance and thus the Residence time of the mixture supplied is achieved. In addition, the available area in a container is optimally used in order to achieve separation over a longer path length by sedimentation of the granular mineral solids present in the liquid-solid mixture. The invention prevents, for the first time, so-called "short-circuit flows" from the outside to the inside of the container, which leads to a less than optimal result in the sedimentation of the solid particles carried in the mixture. So-called round sand traps are known, in which the water with the sand located therein is introduced tangentially, which in some cases forms a spiral flow which effectively supports the settling of the sand. However, the spiral flow is only predetermined by the outer container edge and the tangential introduction, so that favorable separation conditions are only created in the outer edge region of the container. The separation or sedimentation process is reduced by the short-circuit currents already mentioned which run transversely to the main flow. With these known sand traps, they are deposited towards the center, where the sand is then conveyed out of a sand shaft with compressed air.

The invention for the first time optimally continues the spiral flow which forms itself in the edge region, namely up to the discharge point, as a result of which any cross-flow or short-circuit flow is avoided, so that the settling of the sand is supported even more effectively. This increases the efficiency of the separation of granular mineral solids in a liquid-solid mixture.

The forced guidance in spiral form only has to take place in the upper part of the total height of the liquid in the container. Because only there is an ascertainable substantial horizontal flow taking place.

A very even flow, which also enables optimal sedimentation of the solid particles in the mixture, is given when the forced flow is carried out in uniformly winding turns. But it depends Rectangular turns are also possible, but speed fluctuations can still occur here, especially in the corner areas. The corner areas can in turn also form sedimentation-increasing eddies in an optimal manner.

By reducing the spiral distance between the individual turns towards the diversion point, the flow rate from the introduction point to the diversion point can be kept essentially constant, which further increases the degree of separation.

A guide device according to the invention for spiral forced guidance between an inlet and an outlet point in a container, the heavier constituents of the liquid-solid mixture, essentially the granular mineral solids, being separated out by sedimentation, can be readily used in existing devices or systems , as they were explained at the beginning. For this purpose, the guide device must simply be attached in the upper area of the container. In particular, it is possible to attach the guide device to a container lid at intervals.

The efficiency of the device can be increased even further if a mechanical one in front of the inlet point

Pre-stage separating device for separating a part of the suspended matter, slightly and slightly soluble matter in the liquid-solid mixture is arranged. As a result, in the downstream device for separating granular mineral solids, as explained at the beginning, the comprises a guide device according to the invention, achieves even better sedimentation.

A structurally simple but very effective pre-stage separation device consists of a rotatable one

Sieve drum, in the sieve drum wall there are small holes. The inside of the sieve drum is connected to a drain for mixture components of the liquid-solid mixture which do not fit through the holes. A collecting line leading to the inlet point on the container of the downstream combustion device is arranged below the screening drum. In the sieve drum, which has the large number of holes with a diameter between approximately 2 and 5 mm, the organic substances are sieved off and the sand adhering to them is rinsed off.

In particular, it is advantageous if the sieve drum has a slope, which results in better pre-separation and the water can be drained off without further aids.

It is very advantageous if the introduced liquid-solid mixture is guided over a vertical gradient in front of the inlet point, so that the liquid-solid mixture at the inlet point in the container has the advantageous low speed for sedimentation, which depends on

Mixing ratios and the solids to be sedimented is about 0.3 m per second or less.

The diversion point advantageously comprises a drain funnel, which is dimensioned in its angled length so that only a minimal suction effect arises from the drain speed. As in the prior art, the sand or, in general, the granular mineral solids forming the sediment bed is drawn off in small batches and, if appropriate, dewatered. For this purpose, a screw conveyor device, as also disclosed in DE 44 10 969 Cl explained at the beginning, is advantageous.

In an optimal embodiment, the "channel width" specified by the guide device is constant. In combination with the outlet (in particular the head height specified by its shape), a flow unit that is as uniform as possible is achieved.

The inlet and outlet are preferably at the same level, so that "short-circuit currents" below the guide device are further minimized.

The guide device extends - starting from a maximum loading quantity - optimally approximately 100 mm above the water surface.

Brief description of the drawings

In the following, several exemplary embodiments are described and explained in more detail with reference to the accompanying drawings for further explanation and for a better understanding of the invention. It shows:

1 is a schematic side view of a sand washing system according to the invention, which is equipped with a new guide device,

FIG. 2 shows a top view of the device according to FIG. 1,

Fig. 3 is a schematic perspective view of a baffle according to the invention and

Fig. 4 is a schematic plan view of a further embodiment of a guide device according to the invention.

Description of exemplary embodiments of the invention

A first embodiment of the invention is described in more detail below with reference to FIGS. 1 to 3. The sand washing system shown in Fig. 1 comprises a washing and separating container 1, which comprises a funnel part tapering downwards. The container 1 is supported on the floor by means of supports 2. As can be seen from the plan view in FIG. 1, the container 1 has a circular shape in the upper part and is also cylindrical in this part. On one side, in the figures on the right, is above an introduction point 13 in the washing and Separation container 1, a pre-stage separation device 9 is arranged, which is a rotatable

Sieve drum 10 with holes therein and an underlying collecting channel 12 comprises. Both the screening drum 10 and the collecting trough 12 are accommodated in a housing 11. The entire pre-stage separating device has a length that almost corresponds to the diameter of the washing and separating container 1. The sieve drum 10 is driven by a motor, not shown here, and has a gradient. An inlet for the mixture coming from a wastewater treatment plant, for example, which contains granular mineral solids such as sand, organic substances, suspended substances, easily and slightly soluble substances, opens into the interior of the sieve drum. The collecting trough in turn opens into an outlet 14 which is arranged higher than the inlet point 13 in the washing and separating container 1. The outlet 14 and the inlet point 13 are connected to one another via a pipeline.

In the middle of the container there is a funnel 16 which opens into an outlet 17. The upper edge of the funnel determines that

Liquid level WSP. The inclination of the discharge funnel 16, seen in cross section, is designed so that a minimal suction effect arises from the discharge speed of the excess liquid, here water with the suspended substances, easily and slightly soluble substances as well as organic substances carried therein.

An agitator 18 is arranged in the lower region of the washing and separating container 1. In Fig. 1 the agitator is arranged obliquely, but it is also possible to arrange this agitator vertically. The agitator 18 comprises individual paddles, which in the sediment bed 22 which is formed from the sunken granules mineral solids, essentially sand, are rotated via an agitator drive 20 and an intermediate gear 19. This is followed by a screw conveyor 3 connected to the lower container part 1, which, supported by a support 5, projects obliquely upwards. The

Screw conveyor 3 comprises a hollow helix 4 which is driven by a screw drive 7 and an intermediate gear 6. In the upper end region there is an ejection chute 8, via which sand that has been discharged and conveyed by the hollow helix 4 is conveyed out.

As can be seen very well from the plan view according to FIG. 2, a guide device according to the invention in the form of a guide plate 15 is arranged in the upper container part 1. The baffle plate 15 is a spirally wound plate, which initially forms a channel with a substantially constant width together with the container edge, which is then formed by the adjacent baffle plate walls and spirals up to the funnel 16. A spiral guide for the liquid-solid mixture introduced into the container is thus formed. This means that there is an even flow of mixture flowing inwards.

The baffle 15 extends only over a partial depth range below the liquid level WSP, namely to a depth at which there is still a substantially horizontal one

Flow is noticeable. Furthermore, it extends over the liquid level WSP, so that on the

Liquid surfaces floating, for example organic substances or suspended substances, cannot splash over or overflow. 3, in particular, the spiral shape and design of the guide plate 15 are again clearly visible; especially the spiral winding and the height.

The operation of such a device will now be described below. The water mixed with sand, organic substances, suspended substances, easily and sparingly soluble substances, for example from a wastewater treatment plant, is introduced into the rotating sieve drum 10. The organic parts are sieved through the holes in them with a hole size between 2 and 5 mm and the adhering sand is rinsed off. The remaining sand-water mixture is taken up by the collecting channel 12 and passed through the outlet 14 to the inlet point 13. The gradient between the outlet 14 and the inlet point 13 gives the sand-water mixture a speed suitable for the sedimentation taking place in the container.

At this speed, this mixture is at the

The introduction point 13 is introduced tangentially into the washing and separating container 1 filled with water, as can best be seen from FIG. 2. By means of the guide device 15 according to the invention, this tangentially introduced flow is now uniform, i.e. essentially with the same

Speed, about 0.3 m / sec. or underneath it spirally to the discharge point, the funnel 16. During the dwell time in the container 1, the granular mineral solids, essentially the sand, separate from the organic substances, suspended substances, easily and slightly soluble substances that were still present in the introduced mixture, and form a sediment bed 22 in the lower container part 1 The excess Water is discharged via the funnel 1 with the residues located thereon or therein via the outlet 17.

The agitator 18 is operated for thorough mixing in the formed sediment bed 22. The collected sand is continuously transported in batches via the screw conveyor. Due to the hollow-helical design, the extracted sand is also dewatered in the discharge device 3. The sand conveyed by the hollow helix 3 is then filled into a suitable container via the discharge chute 8.

The second embodiment shown in FIG. 4 is a rectangular container 31, in which a baffle plate having rectangular turns comprises an optimization for the length of the section available for sedimentation. Although flow velocity changes occur in the area of the corners of the rectangular windings, there is generally also a better division and positive guidance of the available surface.

Claims

claims

1. A method for separating granular mineral solids such as sand from organic substances, suspended matter, easily and slightly soluble substances in a liquid-solid mixture, such as a mixture from wastewater treatment plants, in which the liquid-solid mixture at a radially external discharge point (13) is introduced tangentially into a container (1), - the liquid-solid mixture flows at such a low speed to a radially inner discharge point (16) in the container (1) that the heavier mixture components, essentially the granular ones, meanwhile mineral solids, the liquid-solid mixture to form a

Sediment bed (22) sink, and the sunken components of the sediment bed (22) are discharged and, if necessary, dewatered, characterized in that the liquid-solid mixture between the inlet point (13) and the outlet point (16) is spirally forced at least over a partial depth range .

2. The method according to claim 1, characterized in that the forced current guidance takes place in uniformly winding turns.

3. The method according to claim 1, characterized in that the positive current is carried out in rectangular turns.

4. The method according to claim 1, 2 or 3, characterized in that the positive guidance by a spiral wound

Guide device (15; 32) is effected, which extends both above and below the liquid level (WSP).

5. The method according to claim 4, characterized in that the spiral distance of the guide device (15; 32) to the diversion point (16) becomes narrower to such an extent that the flow rate remains essentially constant.

6.Director with a spirally wound changing element (15; 32) for the spiral forced guidance of a liquid-solid mixture, which contains granular mineral solids such as sand and also organic substances, suspended substances, easily and slightly soluble substances, such as a mixture of wastewater treatment plants, between a radially outer inlet point (13) and a radially inner outlet point (16) in a container (1), the heavier constituents of the liquid-solid mixture, essentially the granular mineral solids, being separated out by sedimentation.

7. Guide device according to claim 6, characterized in that it extends both above and below the liquid level (WSP).

Guide device according to claim 7, characterized in that the guide device (15; 32) extends to a depth extends below the liquid level (WSP), in which a substantial horizontal flow can still be determined.

9. Guide device according to one of claims 6-8, characterized in that the spiral distance of the guide device (15; 32) to the diversion point (16) decreases continuously.

10. Guide device according to one of claims 6-9, characterized in that the guide device is a guide plate (15; 32).

11. Device for separating granular mineral solids such as sand from organic matter, suspended matter, easily and poorly soluble substances in a liquid-solid mixture, such as a mixture of wastewater treatment plants, with a container (1) for holding the liquid-solid Mixture and for forming a sediment bed (22) from essentially the sedimented solid particles, an inlet point (13) for the liquid-solid mixture for tangential introduction into the container (1), - an outlet point (16) for discharging the excess liquid and the one inside

Suspended matter, organic matter and the like, and a discharge device (3) for discharging and, if necessary, dewatering the sunken components of the sediment bed (22), characterized in that a guide device with a spirally wound changing element (15; 32) for the spiral positive guidance of the

Liquid-solid mixture between the inlet (13) and the outlet (16) is arranged in the container.

12. The apparatus according to claim 11, characterized in that a mechanical pre-stage separation device (9) for separating a part of the suspended solids in the liquid-solid mixture, easily and slightly soluble substances is arranged in front of the inlet point (13).

13. The apparatus according to claim 12, characterized in that - the mechanical pre-stage separating device (9) consists of a rotatable sieve drum (10), in the sieve drum wall of which there are small holes, the sieve drum interior with a derivation for mixture components of the liquid which do not fit through the holes. Solid mixture is connected and a collecting line leading to the inlet point (13) is arranged below the screening drum (10).

14. The apparatus according to claim 13, characterized in that the screening drum (10) has a gradient.

15. The apparatus according to claim 11, characterized in that the guide device (15; 32) extends both above and below the liquid level (WSP).

16. The apparatus according to claim 11, characterized in that the guide device (15; 32) to a depth extends below the liquid level (WSP), in which a substantial horizontal flow can still be determined.

17. The apparatus according to claims 11, characterized in that the spiral distance of the guide device (15; 32) to the diversion point (16) decreases continuously.

18. The apparatus according to claim 11, characterized in that the guide device is a guide plate (15; 32).

19. Device for separating granular mineral solids such as sand from organic matter, suspended matter, easily and slightly soluble substances in a liquid-solid mixture, such as a mixture from wastewater treatment plants, with a container (1) for holding the liquid-solid Mixture and to form a sediment bed (22) from essentially the sedimented solid particles, an inlet point (13) for the liquid-solid mixture for tangential introduction into the container (1), an outlet point (16) for discharging the excess liquid and the located in it

Suspended substances, the organic substances and the like, and a discharge device (3) for discharging and, if necessary, dewatering the sunken components of the sediment bed (22), characterized in that a guide device with a spirally wound changing element (15; 32) for spiral positive guidance of the

Liquid-solid mixture between the inlet (13) and the discharge point (16) is arranged in the container and the channel width formed by the wall element from the inlet (13) to the discharge point (16) is essentially constant.