Abstract:
In a drainage device for draining road surfaces, parking areas, roof surfaces or the like, comprising a trough body and filter material which is situated in the trough body and is intended for cleaning water loaded with solid particles and/or dissolved pollutants, the filter material is a constituent part of a filter device which has a plurality of filter elements which can be handled individually and, if required, can be removed from the trough body, which filter elements each have a water-permeable enveloping wall with the filter material situated within the enveloping wall.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application No. PCT/EP2012/004945, filed on Nov. 30, 2012, entitled “Drainage Device,” which claims priority under 35 U.S.C. §119 to Application No. DE 10 2012 001 574.7 filed on Jan. 27, 2012, entitled “Drainage Device,” the entire contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a drainage device for draining road surfaces, parking areas, roof surfaces or the like, comprising a trough body and filter material which is situated in the trough body for purifying water loaded with solid particles and/or dissolved pollutants. 
       BACKGROUND 
       [0003]    A drainage device of this type is, for example, known from DE 20 2008 004 861 U1. The device disclosed in this publication, which is designed for discharging filtered rain water, comprises a trough body filled with filter granulate. A half-drainage pipe through which the filtered water is drained is embedded in the filter granulate. As time passes, filtration residues accumulate in the filter granulate, necessitating the replacement of the filter granulate. For this purpose, the filter granulate has to be removed from the trough body, which is accomplished by extraction as a rule. The filter granulate also has to be removed for the maintenance of the half-drainage pipe. 
       SUMMARY 
       [0004]    The invention is based on the problem of creating a drainage device of the type referred to above, which can be handled simply and cost-effectively, in particular in terms of maintenance and the replacement of filter material, and with which contaminated water can be filtered more effectively. 
         [0005]    This problem is solved by a drainage device with the features of the independent claim  1  and the features of the independent claim  9 . Further developments of the invention are specified in the dependent claims. 
         [0006]    The drainage device according to the invention is characterised in that the filter material is a constituent part of a filter apparatus which comprises a plurality of filter elements which can be handled individually and, if required, can be removed from the trough body, each of the filter elements having a water-permeable enveloping wall with the filter material placed within the enveloping wall. 
         [0007]    This makes it possible to remove the filter elements from the trough body in a simple way. There is no longer any need to extract filter granulate as, for example, in the case of the prior art mentioned above. Furthermore, specific individual filter elements can be replaced while other filter elements can remain in the trough body. This is, for example, useful if maintenance or repair work has to be performed at a specific point along the trough body. As a whole, the drainage device according to the invention offers a considerable time advantage when replacing filter material or performing maintenance, inspection or repair operations, resulting in not inconsiderable cost advantages. 
         [0008]    In a further development of the invention, the water-permeable enveloping wall is flexible. In a particularly preferred embodiment, the water-permeable enveloping wall is represented by a bag envelope which is in particular made of a woven fabric. In this case, the filter elements can be referred to as filter bags filled with filter material. Alternatively, the enveloping wall could conceivably be rigid, so that the filter elements can be designed as containers filled with filter material. 
         [0009]    In a further development of the invention, the filter apparatus comprises at least one water-permeable filter element support for the filter elements, which is in particular releasably secured in the trough body. In this case, it is possible for the filter element support to remain in the trough body, while only individual filter elements are removed. Alternatively, it is, however, also possible for the filter element support and the filter elements together to form a filter module which can be removed from the trough body. The filter elements are expediently arranged such that they cover the entire width of the trough body. The filter elements can be arranged one behind the other in the longitudinal direction of the trough. The filter elements can be arranged in a single layer or in several layers on top of one another. 
         [0010]    As an alternative to the water-permeable filter element support, the filter elements can be designed to be self-supporting, for example in the case of filter containers filled with filter material. In this case, the self-supporting filter elements can be releasably secured in the trough body itself. 
         [0011]    Filter elements having a flexible enveloping wall, i.e. filter bags for example, can be placed on the filter element support in such a way that they adapt to the shape of the filter element support and bear against an inner wall of the trough body while forming a seal. A sealing action between the filter elements and the inner wall of the trough body is important if any flow bypassing the filter elements is to be prevented. In the case of filter bags, this sealing action can be achieved by a pressure applied by the filter bags to the inner wall of the trough body. As a result, separate sealing elements are no longer required. 
         [0012]    In a further development of the invention, the filter element support is placed above a trough base of the trough body, a lower region of the trough body forming a gutter for purified water below the filter element support. Depending on the distance between the filter element support and the trough base, a gutter having a larger or smaller cross-section is formed. It is therefore possible to use a relatively large area of the trough body for the discharge of purified water, allowing for a high output. In contrast, output is relatively low in the prior art referred to above, because the pipe cross-section of the half-drainage pipe of prior art is kept relatively small as a rule, in order to accommodate as much filter granulate as possible in the trough body. As an alternative to the drainage or rain-water gutter, the invention can also be applied to a soak-away. In this case, purified water is discharged from the filter apparatus for soaking into the ground. 
         [0013]    In a further development of the invention, a filling of filter granules is used as a filter material. Particularly preferred are granules of an ion-exchange material. 
         [0014]    The invention is further characterised in that a water inlet body having a flow-through section with a plurality of flow-through apertures through which contaminated water enters the filter material and a sedimentation chamber for the sedimentation of suspended matter is located above the filter material, the water inlet body having at least one water ducting element via which the contaminated water can be passed into the sedimentation chamber and from there into the flow-through apertures, or else directly into the flow-through apertures while at least partially bypassing the sedimentation chamber. 
         [0015]    Normally, contaminated water is first passed into the sedimentation chamber, where suspended matter can settle. As a result of the rising water level of the sedimentation chamber, the water can be discharged from the water inlet body via the flow-through apertures and reach the filter apparatus. At high levels of precipitation, for example rain, the water can flow directly into the flow-through apertures while partially or wholly bypassing the sedimentation chamber, resulting in a higher water throughput. 
         [0016]    In a particularly preferred embodiment, the water ducting element is arranged above the sedimentation chamber in such a way that, from a specified water volume, water can be passed directly into the flow-through apertures by means of a jumping tower effect while at least partially bypassing the sedimentation chamber. The water ducting element can be designed to be either stationary or adjustable. In an adjustable water ducting element, it would for example be possible to adjust its length or inclination. 
         [0017]    In a particularly preferred embodiment, the water ducting element has an inward- and downward-oriented inlet incline. The water ducting element can be represented by a continuous edge of the water ducting body. Expediently, this edge is uninterrupted. 
         [0018]    In a further development of the invention, the flow-through section of the water inlet body is represented by a dome-shaped high area, which is in particular formed from the base material of the water inlet body and surrounded by the trench-like sedimentation chamber. 
         [0019]    The water inlet body can be placed on the filter elements of the filter apparatus. The weight of the water inlet body and of the water in the water inlet body applies a pressure to the filter elements, so that, in the case of filter elements designed as filter bags, additional pressure can be obtained for sealing the filter elements against the inner wall of the trough body. 
         [0020]    It is particularly expedient if the water inlet body is a component which can be handled separately from the filter module. It is then possible to remove the water inlet body from the trough body without having to remove the filter apparatus. Together, the filter module and the water inlet body form a drainage module which can be removed from the trough body as a unit. Expediently, several such drainage modules are arranged one behind the other in the longitudinal direction of the trough body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    A preferred embodiment of the invention is illustrated in the drawings and will be explained in greater detail below. Of the drawings: 
           [0022]      FIG. 1  is a perspective view of a preferred embodiment of the drainage device according to the invention, 
           [0023]      FIG. 2  is a longitudinal section through the drainage device from  FIG. 1  along line 
           [0024]      FIG. 3  is an enlarged perspective view of the drainage device according to the invention as shown in  FIG. 1 , 
           [0025]      FIG. 4  is a cross-section through the drainage device from  FIG. 1  along line IV-IV, 
           [0026]      FIG. 5  is a perspective view of the drainage device from  FIG. 1  without its grating cover, 
           [0027]      FIG. 6  is a perspective view of a drainage module of the drainage device from  FIG. 1 , 
           [0028]      FIG. 7  is a perspective view of a filter module comprising a filter element support and filter elements, 
           [0029]      FIG. 8  is a perspective view of the filter element support, 
           [0030]      FIG. 9  is a perspective view of the water inlet body of the drainage device, and 
           [0031]      FIG. 10  is a section through the water inlet body from  FIG. 9  along line X-X. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]      FIGS. 1 to 10  show a preferred embodiment of the drainage device  11  according to the invention. The drainage device  11  is used for draining large surfaces such as road surfaces, parking areas or roof surfaces. By way of example, the drainage device  11  according to the invention is explained below in the form of a drainage or rain-water gutter. Alternatively, however, the drainage device  11  could be designed as a soak-away. 
         [0033]    As  FIGS. 1 to 5  show, the drainage device  11  comprises a trough body  12 , which may be made of concrete, for example. As a rule, the trough body  12  is embedded in the soil. The trough body  12  contains a trough  13 , which in the illustrated embodiment consists of a rectangular cross-section adjoined by a circular section. As the name suggests, the trough body  12  is open towards the top, the trough  13  being laterally bounded by two side walls  14   a,    14   b  of the trough body  12 , while the lower end of the trough body  12  forms the trough base  15 . 
         [0034]    As  FIG. 1  shows particularly clearly, the upper end of the trough body  12  is covered by a grating cover  16 . The grating cover  16  is provided with a plurality of inlet openings  17 , through which contaminated water can enter the trough  13 . The grating cover  16  is flush with the surface to be drained, for example a parking area or a road surface. The drainage device  11 , i.e. the trough body  12  with the grating cover  16  in particular, is passable. The material of the trough body  12  and the material of the grating cover  16 , which is made of a metallic material in particular, can be chosen such that heavy loads can pass over it. 
         [0035]    As  FIGS. 1 to 5  show particularly clearly, a filter apparatus  18  is located in the trough  13 . The filter apparatus  18  comprises a plurality of filter elements  19 , which can be handled individually and, if required, removed from the trough body  12 , each of which filter elements  19  has a water-permeable enveloping wall  20  with filter material located within the enveloping wall  20 . 
         [0036]    According to the preferred embodiment, a flexible, water-permeable enveloping wall  20  is provided, which is represented by a bag-type envelope. The bag-type envelope is made of a textile fabric and filled with the filter material, so that the unit as a whole can be referred to as a filter bag. 
         [0037]    Depending on the purification requirements applying to the surface water, various filter materials can be used. It is, for example, possible to use a filling of filter granules  40  ( FIG. 4 ) as filter material. The filter granules expediently have a uniform shape, for example a spherical shape. Such a filling can for example meet the requirements of the separation regulations, so that water purified in this way no longer requires additional filtration in a precipitation tank. 
         [0038]    If requirements are more stringent, for example in the case of water loaded with contaminants, an ion exchanger in granule form can be used as a filter material. With such a filter material, dissolved heavy metal ions can be filtered out, for example. In addition, a high AFS retention is obtained. 
         [0039]    As  FIGS. 6 and 7  show in particular, the filter apparatus  18  comprises at least one water-permeable filter element support  21 , on which the filter elements  19 , i.e. the filter bags for example, are placed. The filter bags adapt to the shape of the filter element support  21  while contacting the inner wall  22  of the trough body  12  and provide a seal between the outside of the bag-type envelope and the inner wall  22  of the trough body  12 , thereby preventing undesirable bypass flow. 
         [0040]    As  FIG. 8  shows, the filter element support  21  can be designed as a sheet metal profile having a plurality of discharge openings  23 , for example in the form of slots. The filter element support  21  comprises a base section  24 , which may, for example, be represented by the sheet metal profile. The base section  24  may be designed in the manner of a saddle, for example. The filter bags then lie on the base section  24 . The filter bags extend across the entire width of the trough  13 , therefore abutting one inner wall on one side and the other inner wall on the opposite side. Below the base section  24  of the filter element support  21 , there are rail-type support sections  25 , by way of which the filter element support  21  is held in the trough body  12 . As the trough body  12  of the illustrated embodiment ends in a circular section at the bottom, resulting in a cross-section reduction, the filter element support  21  does not have to be secured to the inner wall  22  of the trough body  12  by separate fastening means. It is exclusively held in the trough  13  by the wedge action between the support section  25  and the reducing cross-section of the trough  13 . In an alternative variant, the base section could be designed without any discharge openings, for example as a continuous sheet metal profile. In this case, the base section terminates in the radial direction, as shown in  FIG. 8 , at a distance from the inner wall of the trough body  12 , being therefore shorter than the support section  25 . This forms a discharge gap extending in the longitudinal direction between the outer edge of the base section and the inner wall. In this variant, the water is forced to flow downwards and outwards within the filter bag, until it reaches the discharge gap and is discharged there. This extends the dwell time of the water to be purified in the filter bag. 
         [0041]    The filter element support  21  is therefore situated above the trough base  15 , with a gutter for the discharge of purified water forming below the filter element support  21 . As a whole, the filter element support  21  and the filter elements  19  in the form of filter bags form a filter module  26 , which can be removed from the trough body  12  as an assembly. The filter apparatus  18  comprises a plurality of such filter modules  26 , which are lined up one behind the other in the longitudinal direction of the trough. 
         [0042]    As  FIGS. 1 to 5  show in particular, above the filter apparatus  18  there is provided a water inlet body  27 , via which water enters the trough through the grating cover  16 . The water inlet body  27  is expediently designed as a plastic component. As  FIGS. 9 and 10  show in particular, the water inlet body  27  has a box-shaped base section  28 , which encloses a water chamber  29 . The water chamber  29  is basically divided into two different sections. On the one hand, there is provided a flow-through section  31  having a plurality of flow-through apertures  30 , which is represented by a dome-shaped high area of the base of the water inlet body  27 . The water chamber  29  further comprises a sedimentation chamber  32 , which extends in the manner of a trench around the dome-shaped high area of the flow-through section  31 , thereby enclosing it. 
         [0043]    The sedimentation chamber  32  is used for the sedimentation or accumulation of suspended matter. From the sedimentation chamber  32 , contaminated water flows to the flow-through section, where it flows through the flow-through apertures  31  into the filter apparatus  18  placed below. 
         [0044]    An important aspect is that the water inlet body  27  has at least one water ducting element  33 , via which the raw water can be passed into the sedimentation chamber  32  and from there into the flow-through apertures  30 , or else directly into the flow-through apertures  30  while at least partially bypassing the sedimentation chamber  32 . 
         [0045]    In the illustrated embodiment, the water ducting element  33  is represented by a lip-shaped continuous upper edge of the water inlet body  27 , which projects inwards into the region of the water chamber  29 . The water ducting element  33  has an inward- and downward-oriented inlet incline  34 . From a specified water volume, contaminated water flows directly to the flow-through apertures  30  by means of a jumping tower effect, while at least partially bypassing the sedimentation chamber  32 . As a result, a higher water throughput can be obtained at times of heavy precipitation, e.g. heavy rain, thereby avoiding banking As  FIGS. 2 and 3  in particular show, the water inlet body  27  is placed on the filter sacks. The pressure applied by the weight of the water inlet body and the water therein additionally pushes the filter bags against the inner wall  22  of the trough body  12 . 
         [0046]    To prevent bypass flow between the inner wall of the trough body  12  and the outer wall of the water inlet body  27 , a seal is provided. For example, sealing lips  35  can be provided, each of which is installed into a seal groove  36  provided for this purpose on the outside of the base section  28  of the water inlet body. 
         [0047]    Together, the water inlet body  27  and the filter module  26  placed below and comprising filter elements  19 , i.e. filter bags, and filter element supports  21  form a drainage module. This drainage module can be removed from the trough body  12  as an assembly. It is, however, also possible to remove only the water inlet body  27 , while the filter module  26  remains in the trough body. For the removal of the water inlet body  27 , handles  50  are in particular provided on the two opposite end faces of the water inlet body  27 . 
         [0048]    For draining the connected area, for example a parking area, road surface of even roof surface, contaminated water initially enters the trough  13  via the inlet openings  17  of the grating cover  16 . At normal water volumes, the water first flows via the inlet incline  34  of the water ducting element  33  into the sedimentation chamber  32 , where suspended matter settles. Contaminated water then flows via the flow-through apertures  30  of the flow-through section  31  into the filter module  26  placed below, where it enters the filter material through the water-permeable enveloping wall  20  made of sacking to be filtered there. Filtered, purified water is then discharged from the filter bags and flows via the discharge openings  23  in the base section  24  of the filter element support  21  into the gutter placed below, from where it can drain off.