DE102018128600A1 - Filter device - Google Patents

Abstract

A filter device (1) for filtering algae, microorganisms and the like from water comprises a filter space (2) to which water can be fed via an inlet (4), a filter membrane (5) for filtering out algae, microorganisms and the like, an outflow ( 6) for the filtered water, a gassing device (7) for supplying a gas to the filter membrane (5), an agitator (8) for mixing the water in the filter chamber (2) and a discharge device (10) for discharging foam (10) or Contamination on the surface (O) of the water in the filter chamber (2). A cleaning system (11) constructed therefrom is also specified.

Description

The invention relates to a filter device for filtering algae, microorganisms and the like from water and a cleaning system constructed therefrom.

In addition to the actual flora and fauna, micro-organisms such as algae, micro-organisms, bacteria and the like are also present in all saline oceans as well as in fresh water. The microorganisms contained in the world's oceans alone represent a biomass with a practically inexhaustible supply that also grows continuously. So-called algal blooms often occur, especially in heated and essentially immobile waters. This means that the number of algae and microorganisms, for example in g / m ³ , exceeds a certain value, so that the water is depleted of oxygen and, for example, fish suffocate.

To avoid this, it is known that the algae are filtered out of the water. This can be done by adding precipitants, among other things, but this is hardly feasible from a practical and ecological point of view. It is also known to mechanically filter algae out of the water using filter devices, for example by means of centrifuges or by adsorption or by pressure relaxation flotation. Such filter devices can also be designed to be floatable in order to be used in a mobile manner.

The filter devices usually have a filter chamber, to which water is supplied via an inlet, and a filter membrane for filtering out the algae and an outlet downstream of the filter membrane in order to remove the cleaned water again.

However, the problem often arises that the filter membrane is clogged by a filter cake that has to be removed mechanically in order to regain the desired filter performance. This can hardly be avoided with an additional agitator in the filter room.

It is also known to either foam and skim the algae or microorganisms or to design the filter device in the manner of a sedimentation tank. However, only small throughputs are achieved here.

The object of the invention is to develop a filter device for algae such that it can be operated in a simple manner and has a high degree of efficiency. Furthermore, a cleaning system constructed from it should be specified.

According to the invention the object is achieved by the features of claim 1. A cleaning system according to the invention can also be constructed with such a filter device.

The main idea of the invention is that the device for filtering algae, microorganisms and the like comprises a filter space to which the water to be filtered can be supplied by means of an inlet. A filter membrane for filtering out algae, microorganisms and the like is arranged in particular in the bottom of the filter space. Furthermore, a drain for the filtered water is provided below the filter membrane. To keep the filter membrane clean, a gassing device is used to supply a gas to the filter membrane in counterflow to the water, which is preferably arranged below the filter membrane. Furthermore, an agitator is provided in the filter room to keep the water in the filter room in circulation. Finally, there is a discharge device in the filter space for discharging contaminants on the surface of the water in the filter space.

The filter space, which is formed, for example, by a housing made of metal, in particular stainless steel, creates a delimited space in which an increasing algae concentration is obtained through the constant supply of water. The filter space is, for example, cubic, but it can also have any other shape. The area of the filter membrane or of a filter is preferably selected to be large enough that resistance due to the pressure loss when filtering out is minimized. The water flows through one or more inlets into the filter chamber in a flow direction, for example from top to bottom. Algae, microorganisms and the like are filtered out on the bottom-side filter or the filter membrane and the cleaned water emerges from the filter space via an outlet which is arranged behind the filter membrane as seen in the direction of flow.

To avoid clogging of the filter membrane, it is gassed in counterflow. For this purpose, a gassing device is arranged between the outlet and the filter membrane, for example to blow ambient air into the filter chamber from bottom to top. The rising gas bubbles penetrate the filter membrane and remove residues, especially on the top. In addition, the injected gas causes the filtrate to foam. The amount of gas, the gas pressure and the flow rate of the water are matched to one another in such a way that optimal filter performance is achieved. In particular, the flow velocities and volume flows are selected such that the ascending Gas bubbles should not be torn down by the water flow.

In principle, such gassing can alternatively or additionally take place with air nozzles which are distributed in the interior of the filter space in order to keep the surface of the filter membrane clean.

Furthermore, an agitator, also known as a disperser, is provided in the filter chamber, which can be designed in any way per se and, for example, also consists of metal / stainless steel in order to maintain a circulation of the water in the filter chamber and to prevent foam formation on the surface of the water promote. For example, several paddle-shaped and possibly aerodynamically shaped sheets can be rotatably supported via a linkage. The agitator also generates a current parallel to the filter membrane in order to minimize its clogging.

Finally, the foamed algae on the surface of the water are removed from the filter space and collected using a discharge device. The discharge device can, for example, be a fixed component in the form of a flow guide plate. Due to the rotary movement of the agitator and the cross flow generated in a cleaning system composed of several filter devices, the foam floating on the surface of the water is also set in rotation and can be automatically skimmed off with a suitably arranged and shaped flow baffle and sent for further use via a separate outlet . This flow guide plate can also be designed to be height-adjustable, for example by means of screws on one or more vertically arranged perforated rails, in order to achieve an optimal discharge result. As an alternative or in addition, the discharge device can also comprise a movable, that is to say a linearly movable or rotating slide or the like which, by its movement, skims off the foam floating on the surface of the water.

For example, the filter room can have a volume of 375m ³ with a filter area of 125m ² . The filter membrane has a pore size or mesh size of, for example, a maximum of 20 µm, in particular a maximum of 10 µm.

With the filter device, in particular, algae are filtered out of the water, collected and concentrated. The algae or the filtrate can then be used for further purposes. For example, they are composted and used as fertilizers. They can also be used to generate biogas or other fuels. It is also possible to reuse the protein and other nutrients it contains to produce food.

Such a filter device can be designed to be stationary in order to also serve as a wastewater treatment plant. It can also be designed to be mobile, that is to say mounted on or in a vehicle. In particular, it can be installed in a ship, such as a motor or sailing ship or a barge, which is equipped with a preferably movable funnel in order to collect sea water and to feed it to the filter device. Likewise, the filter device can be constructed stationary at a location of high flow speed in a body of water, with corresponding supply and discharge channels being provided. The current can be determined by tides and / or geological conditions. Preferably, the water, regardless of whether in mobile or stationary operation, is first passed through a turbine for energy generation in order to subsequently be fed to the actual filter device. This means that a considerable part of the energy required for operation can be obtained.

The subclaims represent advantageous embodiments of the invention.

In a first embodiment, a foamer is assigned to the inflow or inlets, which already swirls the inflowing water in order to improve the foam formation. The frother can either be designed as a static component or also movable, for example according to the functional principle of a whisk.

All filters or sieves known to the person skilled in the art can be used as the filter membrane, for example a fine-meshed metal grid. In particular, it is proposed that the filter membrane or the filter consist of ceramic. For example, the filter membrane is formed by a ceramic membrane. This can be produced with the mesh size described above and has sufficient strength and resistance, for example to sea water. The surface thereof is preferably hydrophobic and / or provided with the lotus effect in order to prevent residues from accumulating. A mass transfer between the water and the blown air can also be supported.

Furthermore, baffles can be arranged at the desired positions with the desired size and shape at the inlet and outlet and in the filter space in order to guide the water to be filtered in a preferred amount and flow rate. The baffles are rigidly arranged or movable trained to adapt to different volume flows, for example.

The water flowing into the filter device through one or in particular two symmetrically arranged inlets is preferably conducted in such a way that cross-flow or semi-cross-flow filtration takes place. In particular, if, as described below, several filter devices, each with the same size filter surface, are switched or arranged one after the other, the volume flow flowing into each successive filter device is gradually reduced, while the total water flow emerging from all filter devices or an entire cleaning system remains constant. Since decreasing volume flows flow into the successively arranged filter devices, different, decreasing concentrations of the filtrate are then also present in the filter devices. Thus conventional cleaning processes such as flotation and dispersion are combined with simultaneous cross-flow or semi-cross-flow filtration.

A purification system for water can be constructed from such a filter device. When viewed in the direction of flow, a plurality of essentially identical filter devices are preferably arranged one behind the other. The flow conditions are preferably selected such that a smaller volume flow occurs in each successive filter device, in particular with the same flow rate in each case. Thus, cross-flow or semi-cross-flow filtration can be obtained. Thus, with a compact structure of the entire cleaning system, an optimal filter result with, for example, maximum algae yield can be achieved. In principle, the filter devices can also be arranged as a square or rectangle. It can be seen that, for example, a central feed line is provided, from which the water to be cleaned is in each case supplied to the individual filter devices via pipelines. Likewise, the respective processes for the purified water can be combined into a central process.

It can be seen that all components of the filter device are controlled centrally, for example in order to be able to set the throughput quantity of water and gas and all functionalities. For this purpose, valves, flow meters, sensors and the like are provided.

In the foregoing, the invention was essentially described in connection with the filtering of sea water, but it can be seen that the filter device or cleaning system can also be used in all other fields of technology.

It goes without saying that the features mentioned above and still to be explained below can be used not only in the respectively specified combination but also in other combinations. The scope of the invention is defined only by the claims.

• 1 eine Filtervorrichtung in schematischer Darstellung und
• 2 eine zusammengesetzte Reinigungsanlage.

The invention is explained in more detail below using an exemplary embodiment with reference to the associated drawing. The figures in the drawing show:

• 1 a filter device in a schematic representation and
• 2nd a composite cleaning system.

In the 1 is purely schematic of a filter device 1 shown in cross section. It has a filter room 2nd , for example, by a housing 3rd is made of stainless steel. Via an inflow 4th water flows in the direction of flow according to the arrow S into the filter room 2nd and leaves it again via a drain 7 at the bottom of the filter room 2nd .

A filter membrane is used to clean the water, in particular from algae, microorganisms and the like 5 , which is designed, for example, as a metal grid or as a ceramic membrane or filter and has, for example, a hydrophobic and / or lotus effect surface.

In the direction of flow according to the arrow S seen below the filter membrane 5 is a fumigation facility 7 arranged, for example a pressurized, perforated pipeline network, which is only indicated schematically here. The escaping gas flows in the opposite direction according to the arrow G upwards and thereby passes through the filter membrane 5 . This leaves residues on the filter membrane 5 detached from this and thus their clogging avoided.

There is also an agitator 8th provided that, as by the double arrow D indicated, is rotatably driven. With the agitator 8th is a mixing of the water in the filter room 2nd achieved. The agitator 8th includes, for example, some paddles, which are rotatably mounted on a frame, around a stream parallel to the filter membrane 5 to generate, so that their clogging or clogging is reduced.

On the surface O the water forms a foam 10th , which consists of foamed algae, and is indicated here schematically with wavy lines. The foam 10th is through a discharge device 9 , here one according to the arrow L linearly movable slide, from the filter room 2nd carried out and preferably collected. With that according to the arrow L linearly movable slide is the one on the surface O the water floating foam 10th skimmed off. The discharge device 9 can also be designed in a simple manner as in particular a height-adjustable flow guide plate, which automatically acts on the surface O of the water floating and co-rotating with the water 10th skimmed off and feeds, for example, a separate outlet for further use.

Through the combination of filtration on the filter membrane 5 and foaming by the rising gas and by the stirrer 8th For example, the algae concentration increases with the amount of filtered water in the foam 10th steadily until it has reached a desired value. The foam 10th can then be composted, for example, or further processed into fuels, food or other end products.

In 2nd is also purely schematic of a cleaning system 11 pictured, which consists of four filter devices 1 is composed, the filter devices 1 are simply reproduced as a block. From the flow direction of the water according to the arrow S it can be seen that all four filter devices 1 Water is supplied, which then flows out cleaned. There may also be more or fewer filter devices 1 be provided, they can also be arranged square or rectangular when viewed from above. The filter devices 1 for example two inlets arranged in particular symmetrically 4th and one sequence each 6 exhibit.

Such a filter device 1 , or cleaning system 11 , is built stationary, for example, and can also function as a sewage treatment plant. However, it is preferably installed in a mobile manner, for example in a sailing ship, a trimaran would provide the process with particular stability, and this water is taken up, cleaned and released again when it travels through the water. In this way, an algal bloom in seawater can be combated efficiently. A substantial part of the energy required preferably comes from a turbine drive which is driven by the speed of the ship through the water. After the flowing water has passed the turbine and given part of its kinetic energy to it, the water becomes the actual filter device 1 or the cleaning system 11 fed. A flowing or flowing body of water can also flow through such a filter device 1 getting cleaned.

Reference symbol list

1

Filter device

2nd

Filter space

3rd

casing

4th

Intake

5

Filter membrane

6

procedure

7

Fumigation facility

8th

Agitator

9

Discharge device

10th

foam

11

Cleaning system

S

arrow

G

arrow

D

Double arrow

L

arrow

O

surface

Claims (6)

Filter device (1) for filtering algae, microorganisms and the like from water comprising a filter chamber (2) to which water can be fed via an inlet (4), a filter membrane (5) for filtering out algae, microorganisms and the like, - a drain (6) for the filtered water, - A gassing device (7) for supplying a gas to the filter membrane (5), - An agitator (8) for mixing the water in the filter chamber (2) and - A discharge device (10) for discharging foam (10) or impurities on the surface (O) of the water in the filter chamber (2). Filter device (1) after Claim 1 , characterized in that a foamer is assigned to the inlet (4). Filter device (1) after Claim 1 or 2nd , characterized in that the filter membrane (5) consists of ceramic. Filter device (1) according to one of the Claims 1 to 3rd , characterized in that the filter chamber (2) are assigned baffles. Filter device (1) according to one of the Claims 1 to 4th , characterized in that a cross-flow filtration takes place in the filter device (1). Cleaning system (11) for filtering algae, microorganisms and the like from water comprising one or more filter devices according to one of the Claims 1 to 5 .

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