GB2448399A

GB2448399A - Apparatus for removing inorganic components from sewage in a sewer

Info

Publication number: GB2448399A
Application number: GB0805539A
Authority: GB
Inventors: Christian Frommann; Franz Spenger
Original assignee: Hans Huber AG Maschine und Anlagenbau
Current assignee: Huber SE
Priority date: 2007-04-10
Filing date: 2008-03-27
Publication date: 2008-10-15
Anticipated expiration: 2028-03-27
Also published as: GB0805539D0; GB2448399A8; DE102007017069A1; GB2448399B

Abstract

Apparatus for removing inorganic components (10) from sewage in a sewer (1) comprises a flow device (2), a discharge apparatus (4) and a sieve apparatus (6). The flow device (2) is arranged above the sewer bottom (17) in order that it effects a sewage flow at least partially in the direction of the sewer bottom (17) and/or the sieve apparatus (6).

Description

Apparatus and Method for Removing Inorganic Components from Sewage in a

Sewer The invention relates to an apparatus for a sewer for removing inorganic components from sewage with a flow device and assigned to this flow device, a discharge apparatus which is assigned a sieve apparatus, as well as to a sewer with a corresponding apparatus. In addition, a method is proposed for removing inorganic components from sewage in a sewer, in which the inorganic components are held back by a sieve apparatus, and removed from the sewer by a discharge apparatus associated with the sieve apparatus.

In order to relieve the load on physical andlor chemical sewage treatment apparatuses, it has long been known to remove coarse, in general, inorganic impurities, such as, stones, metal or synthetic material from the sewage by physical methods. Such mechanical treatment steps, as a rule, consist of a raking system or sieve system, by means of which suspended solids are taken out of the sewage and then fed to a corresponding recycling device.

Thus, for example DE 29 21 922 C2 describes a screen rake for wastewater treatment arranged in a sewer passage, and a lifting tool for horizontal and vertical movement of the rake in the flow path of the sewage, and for the swiveling the rake into and out of the through-flow area of the sewage is assigned to the screen rake. The rake has a drainage apparatus that is designed as a press, which has a pressure plate arranged on the screen rake and a counter pressure plate cooperating with it that is arranged above the through-flow area of the sewer. However, the removed impurities consist not only of inorganic pollutants, but also of organic matter, such as fecal matter or bio-waste, which have a relatively high water content. However, as such impurities can be compressed only with difficulty, a satisfactory removal of the water using press apparatuses is therefore expensive.

In order to address this problem, DE 42 22 128 Al proposes a method and an apparatus for improving the processing of sewage solids, sand, refuse, or the like. For the purpose of as good a dumping capability and combustion as possible, in dependence on the moisture content and content of harmful substances, a stirring device is provided, by means of which organic matter adhering to the solids is dissolved and removed with the fluid. In order to protect the drive motor and the drive axle of the stirring device from organic pollutants, especially long fiber impurities, the stirring device is arranged in a recess of the sewer bottom such that only the stirring wheel projects upwards into the sewer. This arrangement has the disadvantage that such an apparatus can be integrated into existing sewers only by making structural changes. In addition, through the arrangement of the stirring device close to the bottom, a satisfactory stirring of the sewage and connected with this a reliable separation of the organic impurities from the sewage is only conditionally possible.

Thus, the objective of the present invention is to propose an apparatus for integration into an existing sewer and a method, which permits a reliable separation of inorganic and organic impurities.

The objective is solved by the independent patent claims.

According to the invention, it is proposed that the flow device is arranged above the sewer bottom such that it effects a sewage flow at least partially in the direction of the sewer bottom and/or the sieve apparatus. Through the arrangement of the flow device according to the invention, it is achieved in a simple way, that a strong, turbulent flow is created in front of the discharge apparatus, which is arranged downstream. This flow is attained in that the sewage is not only set into a rotational motion by the flow device, but is also pressed against the sewer bottom and/or the sieve apparatus through the targeted flow direction. Through this, the sewage is again diverted by the sewer bottom and/or the sieve apparatus, in particular, when the latter is already at least partially clogged with impurities, resulting in a strong turbulent flow. The arising forces, eventually, cause a wash out of organic impurities, in particular, of the fecal matter or other bio-waste that is carried along by the sewage. Here, these are reliably removed from the inorganic components and at the same time broken down such that they can pass the sieve apparatus. In addition, due to the strong turbulence in the sewer, also long fiber inorganic impurities hardly collect on the flow device.

Downstream from the flow device itself is, in turn, a discharge device with a sieve device. The organic impurities solubilized by the flow device can pass the sieve apparatus, whereas inorganic impurities separated by the flow collect in the sieve device and finally can be discharged from the sewer by the discharge apparatus. They are ultimately collected in a landfill or recycled in other ways. Because the solubilized organic pollution can pass the sieve apparatus, the discharged quantity of waste can be reduced significantly, in addition, subsequent biological treatment steps are positively influenced by the organic impurities.

It is particularly favorable when the flow device is movably supported so that the flow direction is variable. Through this, the direction of the sewage flow can be exactly adjusted to the flow speed of the sewage within the sewer or to the degree of the pollution of the sewage. Also, at the same time, the geometry of the sewer or the possibly present installed equipment can be taken into account in a simple way. Here however, the flow direction according to the invention should be maintained in order to utilize the effect described above.

If an adjustable mounting device is assigned to the flow device, the distance between the flow device and the sieve arrangement and/or between the flow device and the sewer bottom can be adjusted to correspond to the geometry of the sewer as well as to the degree of pollution. For this, the mounting device can be attached directly to the sieve apparatus or the discharge apparatus, but can also be attached to the sewer wall.

In addition it is an advantage, if the flow device is affixed to a swivel arm, which in turn is connected to the wall of the sewer or the sieve arrangement or the discharge arrangement. Through this, a stable, and at the same time also, variably adjustable attachment is realized. Through this, the angle between the longitudinal axis of the sewer and the flow direction of the flow device can be easily changed, and adapted to the respective conditions.

Also, a motor and/or a hydraulic drive is conceivable, which is assigned to the swivel arm and permits a controlled movement of the same, or of the flow device. In order to improve the effectiveness of the flow device, also a continuous variation of the named angle can be advantageous.

In an advantageous design, the flow device can also have nozzles for creating the sewage flow. Either air, or alternatively, or additionally, water can be pumped through these nozzles. Here too, the nozzles can be movably supported or have movable baffles in order to vary the direction of the flow.

If the flow device is an agitator, the disintegration of the organic impurities is caused on the one hand by the generated sewage flow. In addition, the disintegration is also supported by the direct contact of the impurities with the agitator blades. In order to avoid that, in particular, long fiber inorganic impurities collect in the area of the agitator blades and/or the drive axle of the agitator, it can be helpful if the agitator has sharp-edged and/or coated agitator blades.

In addition, it is of particular advantage if the agitator has an impeller.

Through an advantageous design of the impeller, in particular, due to the use of blades whose flow edges are rounded similarly to those of a ship propeller, it is prevented that fibrous impurities that are carried along by the sewage, and which have a tendency to get entwined, accumulate on the agitator. In particular, if the impeller has a fiber-repelling, self-cleaning surface, a reliable operation of the agitator can be guaranteed. In addition, the direction of the sewage flow can be controlled by an agitator with an impeller in a defined way, not the least of which is a positive effect on the above named disintegration of the organic impurities.

Advantageously, an air injection apparatus is assigned to the agitator. The injection of air additionally supports the turbulent flow, and with it, the breaking down effect or wash-out effect of organic impurities. In the process, the injection can occur continuously, but also in pulses.

Advantageously, the discharge apparatus is a screw conveyor. Screw conveyors have the advantage that they are relatively robust and yet, in their construction can be designed relatively simply, and can be run in continuous operation as well as for specific time periods. The screw conveyor is arranged relative to the sewer such that the longitudinal axis of the screw conveyor encloses an acute angle with the longitudinal axis of the sewer. If the screw conveyor is arranged such that it inclines in a direction facing away from the flow device, impurities that collect in the sieve cover are captured particularly reliably by the screw conveyor.

Through this, a backsliding into the sewer is effectively minimized.

However, a vertical arrangement of the screw conveyor relative to the longitudinal axis of the sewer is not excluded. Obviously, other discharge apparatuses can also be used, for example, conveyor belts or conveyor chains, which could, however, possibly have an increased susceptibility to fibrous impurities.

It is particularly advantageous if the sieve apparatus is formed by a sieve cover, which at least partially surrounds the screw conveyor. Due to the sewage flow, impurities that are not broken down collect in the area of the sieve cover and are subsequently caught by the screw conveyer and discharged from the sewer. At the same time, a continuous cleaning of the sieve cover is achieved due to the rotation of the screw conveyor.

It is also advantageous when the operation of the flow device and/or the screw conveyor can be controlled via a control unit. Through this, the corresponding apparatus can be operated depending on the degree of pollution of the sewage, such that an especially favorable energy efficiency results. With the control unit the named devices can not only be switched on or off. In addition, the rotational speed of the screw conveyor or the rotational speed of the agitator can be controlled as desired. In order to enable the automatic control, appropriate sensors can also be assigned to the apparatus according to the invention, which sensors register the degree of pollution, the sewage level and/or the flow speed of the sewage within the sewer.

If a reversible drive is assigned to the agitator and/or the screw conveyor, a particularly reliable operation of the apparatus is guaranteed. Through this, it is possible on the one hand, through changing the flow direction of the flow device, to increase the turbulence of the created sewage flow. On the other hand, changing the flow direction of the discharge apparatus and/or the flow direction of the flow device can counteract a blockage of the discharge device or eliminate such a blockage.

It is particularly advantageous if a seal is assigned to the sieve apparatus.

This seal is advantageously arranged in the area between the sieve apparatus and the wall of the sewer. Through this, it can be prevented efficiently that impurities that are not broken down can pass the discharge apparatus.

If the seal is composed at least partially of neoprene, the material used is wear-resistant and yet flexible. However, other seal materials can also be used, so long as they have sufficient durability.

Advantageously flow baffles can be assigned to the discharge apparatus, which baffles taper the sewer cross section to the cross section of the discharge apparatus. Also, the flow direction, which is created by the flow device, can be purposefully influenced by such baffles in order to take into account the structural conditions within the sewer.

If an emergency overflow is assigned to the apparatus, it can be advantageously guaranteed that the sewage can also pass the apparatus if the discharge apparatus fails and, as a result, the sieve apparatus is blocked. Such an emergency overflow can be realized, for example, in that at least one of the flow baffles does not extend up to the top of the sewer.

Thus, a flow gap is present between the upper edge of the flow baffle and the top of the sewer, through which the sewage can flow if the flow path according to the invention is not passable. Naturally, other solutions are also conceivable, for example, the arrangement of a bypass or a valve, which opens automatically at a defined sewage level.

While the discharge device serves mainly for discharging especially inorganic impurities, it also can also be advantageous if a press apparatus is additionally assigned to the discharge device. Through this, it is guaranteed that on the one hand, the volume of the impurities removed from the sewage is reduced. On the other hand, sewage water, which is removed from the impurities by the press procedure, flows back into the sewer via the discharge device. For this, the press apparatus is advantageously arranged on the top end of the discharge apparatus.

If a screw conveyor is used as the discharge apparatus, it is especially advantageous if the thread height of the screw conveyer decreases in the direction of conveyance. Through this, a press procedure of the impurities in the direction of the top end of the screw conveyor occurs in a simple way, and has the above named advantages.

The sewer according to the invention is distinguished in that it has an apparatus according to the above description. Such an apparatus can be subsequently integrated into existing sewers in a simple way, but can also be included in new plans of sewers.

Furthermore, a method for removing inorganic components from sewage in a sewer is proposed. According to the invention, a flow is created in the sewage in front of a sieve apparatus, where the flow is directed at least partially in the direction of the sewer bottom and/or the sieve apparatus.

This flow device, which for example, is formed by an agitator, creates a turbulent flow within the sewage, which effects a loosening of the organic impurities from the inorganic carrier material. Along with this wash-out procedure, the organic impurities are strongly stirred, resulting in a reduction of the aggregate size. In the process, the solubilizing of the organic impurities is caused not only by the primary sewage flow created by the flow device. Additionally, due to the flow direction according to the invention, at least partially in the direction of the sewer bottom and/or the sieve apparatus, a reversal of the sewage flow occurs and with it, an increase in the turbulence of the flow. The disintegration of the organic impurities is significantly improved by this. Contributing to this improvement is the fact that not only the sewage, but rather also the organic impurities are pressed against the sewer bottom and/or the sieve apparatus, and with it are at least partially deflected. In the process, the aggregate size of the organic impurities is reduced to a size which lies below the mesh size of the sieve cover. Through this, the organic material passes the sieve apparatus, and so passes the discharge apparatus, and even has a positive effect on a subsequent biological cleaning stage.

In addition, the sewage flow prevents that impurities can collect and accumulate in the area of the sewer bottom in the case of a low water level, because during the operation of the flow device, they are continuously stirred up and advanced in the direction of the sieve apparatus and the discharge apparatus.

Advantageously the operation of the discharge apparatus and/or the flow device is controlled by a control unit. In this control unit, for example, programs can be stored, which control a defined switching on and off of the named devices interdependently or depending on factors such as the type and intensity of pollution of the sewage, or for example, of the sewage level. Also, the control unit can be coupled with sensors, which detect the named factors.

It is especially advantageous, if the discharge apparatus and/or the flow device are driven in pulses. Along with the energy savings, this has a further decisive advantage. Namely, if both devices are not driven for a specific period, a covering of the sieve device by the present impurities occurs. This eventually causes a built-up of sewage in front of the sieve device. Through this, sufficient sewage always collects in the area of the flow device, even with a low volume flow of the sewage, such that during subsequent operation of the flow device a turbulent sewage flow and connected to it, disintegration of the organic impurities, can be guaranteed.

In addition, the pulsed operation of the flow device with especially short intervals can also have positive effect on the flow behavior, in particular, on the strength of the turbulence and with it on the degree of disintegration of the organic impurities.

If the direction of conveyance of the discharge apparatus and/or the flow direction of the flow device can be controlled reversibly, an especially reliable operation of the apparatus is guaranteed. Thus, by reversing the flow direction of the flow device, the turbulence of the created sewage flow can be increased. In addition, a blockage of the discharge apparatus can be counteracted, or such a blockage can be cleared.

It is additionally advantageous if the discharge apparatus and/or the flow device are operated essentially alternating. If namely, the discharge apparatus is operated only when the flow device is not operating, it is thus prevented that inorganic components, which have collected in the area of the sieve cover are again washed out.

However, it can also be advantageous, if the discharge apparatus and/or the flow device are operated in a time staggered manner. Thus, it can definitely be favorable, depending on the sewage level, the type of pollution or the level of pollution, if the discharge apparatus is not activated until the flow device has already operated for a determined time, or vice versa.

Naturally, both devices can also be operated completely independently of each other. Thus, an operation of the flow device depending on the type of pollution -and amount thereof, is sensible, whereas the discharge device should be operated primarily when a determined quantity of inorganic components has collected on the sieve apparatus.

Likewise, it is especially advantageous if the discharge apparatus and/or the flow device are operated depending on the level of sewage in front of the sieve apparatus, because this can be an indication that the sieve apparatus is about to be blocked or at least is loaded with a certain quantity of impurities.

In the following the invention is explained using the Figures. They show: Figure 1 a schematic side view of a sewer with an apparatus according to the invention, and Figure 2 a schematic top view of the sewer from Figure 1.

Figure 1 shows a schematic side view of a sewer 1 with a flow device 2 in the form of an agitator 3, and a discharge apparatus 4, designed as a screw conveyor 5. The screw conveyor 5 is assigned a sieve apparatus 6 in the area of the sewer 1 on the side facing away from the agitator, where the sieve apparatus in the exemplary embodiment shown is formed by a sieve cover 7.

Organic impurities 8, which are located in the sewage, are captured by the flow, which is created by the agitator 3. This flow is indicated by arrows.

Through the flow, supported by the chaff effect of the impeller 9 of the agitator 3, the organic impurities 8 are broken down or washed-out from inorganic components 10.

The thusly broken down organic impurities 8 then pass the sieve cover 7, whereas inorganic components 10, such as stones, fibrous refuse, metal or plastic, essentially retain their size, and are detained by the sieve cover 7.

These are then captured by the rotating screw conveyor 5, and transported upwards. As can be seen in the figure, the height of the threads of the screw conveyor decreases with increasing conveyor height. Through this, the carried-along, mainly inorganic components 10 are subjected to a press procedure. This effects a general reduction in the volume of the discharged material, in connection with a pressing out of sewage water that is still contained. The sewage water then flows along the wall of the screw conveyor back into the sewer 1. The components 10 that are removed from the sewage, can afterwards, depending on need, be led to a further recycling device, or transferred to intermediate storage, for example, in a container 11. Naturally, the corresponding components 10 can also leave the screw conveyer 5 un-pressed, if a compression is not desired. In this case, the screw conveyor 5 has a uniform thread height.

The agitator 3 itself is attached to a swivel arm 12. In order to change the flow direction of the agitator 3, either the connection between the sewer wall and the swivel arm 12, or correspondingly between the swivel arm 12 and the flow device 2, can be changed. Also, the possibility exists to equip the appropriate connection site with a movement device, for example, a drive motor 13. The agitator 3 or the swivel arm 12 can alternatively also be fastened to the wall of the screw conveyor or its attachment, such that an especially compact apparatus results, which can be easily integrated into existing sewers 1.

In addition also an air injection apparatus, which supports the sewage flow created by the flow device 2 can be assigned to the apparatus. This can be arranged either in the bottom area of the sewer 1 or also be a component of the flow device 2 in the form of nozzles attached upon it.

In the case of a blockage of the screw conveyor 5, a pivoting of the agitator 3 in the direction of the screw conveyor 5 is possible due to its movable support, such that the resulting sewage flow effects a flushing of the screw conveyor 5. At the same time, or alternatively, due to a reversible drive device 14 of the screw conveyor 5, the direction of conveyance can be reversed, such that possibly blocked material can again reach the area of the sewage flow.

As can be seen in Figure 2, baffles 15 are assigned to the sieve cover 7, where said baffles essentially taper the sewer cross section to the diameter of the sieve cover 7. This achieves that the sewage is led targeted in the direction of the sieve cover 7. There, the baffles 15 advantageously have a height which is less than the height of the sewer. Through this, in the upper region of the sewer 1, a flow gap 18 arises, which serves as an emergency overflow. This emergency overflow eventually allows a passage of the sewage, if the flow path according to the invention should be blocked.

The sieve cover 7, or as in the example shown, the baffles 15 are, on their part, provided with a seal 16 relative to the sewer wall. This seal 16 can, for example, be composed at least partially of neoprene, because this material, on the one hand, is flexible, and on the other hand, also has a particularly abrasion-proof surface. Naturally, other seals 16 can also be used, for example, packing rubber or different filler or grouting compounds.

The present invention was explained in detail using an exemplary embodiment. Modifications of the invention are easily possible in the scope of the patent claims, wherein expressly all features listed in the description and in the description of the figures can be realized in any combination with each other, insofar as this appears meaningful and possible.

Claims

1. Apparatus for a sewer (1) for removal of inorganic components (10) from sewage with a flow device (2) and, assigned to the flow device (2), a discharge apparatus (4), which a sieve apparatus (6) is assigned to, characterized in that the flow device (2) is arranged above the bottom of the sewer (17) in such a way that it effects a sewage flow at least partially in the direction of the sewer bottom (17) and/or the sieve apparatus (6).

2. Apparatus according to Claim 1, characterized in that the flow device (2) is movably supported.

3. Apparatus according to one or both of the preceding claims, characterized in that an adjustable attachment device is assigned to the flow device (2), which device allows an adjustment of the distance between the flow device (2) and the sieve apparatus (6) and/or between the flow device (2) and the sewer bottom (17).

4. Apparatus according to one or more of the preceding claims, characterized in that the flow device (2) is fastened to a swivel arm (12).

5. Apparatus according to one or more of the preceding claims, characterized in that the flow device (2) has nozzles for creating a sewage flow.

6. Apparatus according to one or more of the preceding claims, characterized in that the flow device (2) is an agitator (3).

7. Apparatus according to Claim 6, characterized in that the agitator (3) has an, in particular self-cleaning impeller (9).

8. Apparatus according to one or more of the preceding claims, characterized in that an air injection apparatus is assigned to the agitator (3).

9. Apparatus according to one or more of the preceding claims, characterized in that the discharge apparatus (4) is a screw conveyor (5).

10. Apparatus according to Claim 9, characterized in that the sieve apparatus (6) is formed by a sieve cover (7), which surrounds the screw conveyor (5) at least partially.

11. Apparatus according to one or more of the preceding claims, characterized in that the operation of the flow device (2) and/or the screw conveyor (5) is controllable via a control unit.

12. Apparatus according to one or more of the preceding claims, characterized in that a reversible drive is assigned to the agitator (3) and/or the screw conveyor (5).

13. Apparatus according to one or more of the preceding claims, characterized in that a seal (16) is assigned to the sieve apparatus (6).

14. Apparatus according to Claim 13, characterized in that the seal (16) is composed at least partially of neoprene.

15. Apparatus according to one or more of the preceding claims, characterized in that baffles (15) are assigned to the discharge apparatus (4).

16. Apparatus according to one or more of the preceding claims, characterized in that an emergency overflow is assigned to the apparatus.

17. Apparatus according to one or more of the preceding claims, characterized in that a press apparatus is assigned to the discharge apparatus (4).

18. Apparatus according to one or more of the preceding claims, characterized in that the thread height of the screw conveyor (5) decreases in the direction of conveyance.

19. Sewer, characterized in that it has an apparatus according to one or more of the preceding claims.

20. Method for the removal of inorganic components (10) from sewage in a sewer (1), wherein the inorganic components (10) are held back by a sieve apparatus (6) and are removed from the sewer (1) by a discharge apparatus (4) assigned to the sieve apparatus (6), characterized in that in the sewage in front of the sieve apparatus (6), a flow is created, which is directed at least partially in the direction of the sewer bottom (17) and/or the sieve apparatus (6).

21. Method according to Claim 20, characterized in that the operation of the discharge apparatus (4) and/or the flow device (2) is controlled by a control unit.

22. Method according to one or more of the preceding claims, characterized in that the discharge apparatus (4) and/or the flow device (2) are driven in pulses.

23. Method according to one or more of the preceding claims, characterized in that the discharge apparatus (4) and/or the flow device (2) can be controlled reversibly.

24. Method according to one or more of the preceding claims, characterized in that the discharge apparatus (4) and/or the flow device (2) are driven essentially alternately.

25. Method according to one or more of the preceding claims, characterized in that the discharge apparatus (4) and/or the flow device (2) are driven staggered.

26. Method according to one or more of the preceding claims, characterized in that the discharge apparatus (4) and/or the flow device (2) are driven depending on the sewage level in front of the sieve apparatus (6).

27. Apparatus for a sewer for removal of inorganic components from sewage substantially as described herein with reference to the accompanying figures.

28. Method for the removal of inorganic components from sewage in a sewer substantially as described herein with reference to the accompanying figures.