Abstract:
An ion removal arrangement includes a filter having a filter material made of synthetic or naturally occurring crystalline hydrated aluminum silicates having a framework structure, which contain alkaline or alkaline earth ions. The filter is formed as a double pipe cartridge having an inner pipe and an outer pipe. The filter material is filled in the annular space between the inner pipe and the outer pipe. The filter is installed in the cast iron gutter pipe of a gutter system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. patent application Ser. No. 09/468,426, filed on Dec. 21, 1999, now U.S. Pat. No. 6,248,233. 
    
    
     BACKGROUND OF THE INVENTION 
     As a result of increased environmental awareness and the trend toward conserving natural water resources, the rainwater running off a roof is usually no longer conducted to a water treatment plant via the sewerage system, but rather increasingly is collected. It is then often used for watering gardens or filling ponds or used in the household as utility water, for example, for flushing toilets. 
     Usually rainwater is collected as roof runoff water. It contains, in addition to heavy metal dust from the atmosphere, dust accumulated on the roof surfaces coming from the environment or from the roofing materials. 
     It is known that metallic materials, such as zinc, lead, or copper, which are used as roofing materials or in the construction of gutters, are subject to corrosion due to the effect of air and rain. The amount of metal ions released into the roof runoff water as a result depends on different factors, which include the intensity and amount of the respective precipitation. For this very reason, the environmental friendliness of metallic roofing materials is presently the subject of much critical discussion. 
     In those cases where roof runoff water is not collected, it is conducted directly to water treatment plants via the sewerage system. Roof runoff water is, however, increasingly drained away directly, so that release of heavy metals into the environment cannot be avoided. Minimizing the release of heavy metals into the soil or natural waters would therefore reduce environmental pollution and reduce the metal content in the sludges produced in water treatment plants. Minimized heavy metal release allow roof runoff water to be used for different applications. Thus, for example, the usage of drinking water, treated at a high cost, for different purposes in the house and garden could be substantially reduced. 
     It is known that neutralizing systems can be installed at water treatment plants to precipitate heavy metals. This can, however, only be done centrally due to the size of such systems. These are expensive systems to build. In addition, they cannot capture roof runoff water. 
     Progressing from the related art, the object of the present invention is to provide an arrangement for removing heavy metal ions from roof runoff waters that can be easily and relatively inexpensively installed directly on the building either in new or existing structures. 
     SUMMARY OF THE INVENTION 
     The present invention provides an apparatus for removing heavy metal ions from roof runoff waters. A filter having a filter material made of synthetic or natural crystalline hydrated aluminum silicates and having a skeleton structure containing alkaline or alkaline earth ions is used according to the present invention. Such a filter is arranged immediately downstream from a gutter system. The advantage of such a filter material is that it is easy to handle, inexpensive, regeneratable, and hygienically non-objectionable. The roof runoff water thus purified can be used for different purposes in the household, garden, or pond without causing considerable environmental pollution. The invention also makes it possible to easily drain off roof runoff water into the soil or into natural waters. 
     The filter material can be regenerated and reused in filters via repeated ion exchange. Thus ion exchange costs are kept low and natural resources are saved. Furthermore, chemically bound heavy metals can be recovered so that they can be reused with only negligible amounts of waste being generated. 
     The filter material is preferably formed by compounds of the zeolite group. However, other materials with ion exchange properties can also be used. Natural zeolite include, for example, chabasite, mordenite, heulandite, clinoptilolite, laumontite, natrolite, analcim, philipsite, and/or also clays such as bentonite. One zeolith alone or different zeoliths can be used as mixtures. Depending on the size of the surface exposed to precipitation, the type of roof metal (zinc, copper, or lead) and the metal content of the roofing material or gutter, the amounts of filter material naturally vary. 
     According to a further aspect of the invention, it can be of advantage if absorbing means are added to the filter material. These may include, for example, activated carbon, iron oxide, or dolomite. Clinoptilolith or mixtures of clinoptilolith and other zeoliths are preferably used. 
     According to a further aspect of the invention, an arrangement is provided that is particularly well suited for surfaces exposed to precipitation measuring less than about 160 sq.m. This size corresponds to the DN 100 downpipe normally used in these cases. The filter is designed as a double-pipe cartridge with an inner pipe and an outer pipe with a filter material filled in the annular space between the inner pipe and the outer pipe. It is attached to the cast iron gutter pipe located above the ground surface of a gutter system so that it can be replaced. The cast iron gutter pipe normally terminates a DN 100 downpipe at the ground surface. Since the cast iron gutter pipe is usually coupled to the downpipe via a sliding cast iron gutter pipe cap, the cast iron gutter pipe can be turned after sliding the cast iron gutter pipe cap upward and the filter can then be easily changed. 
     In the event of a normal rainfall, the roof runoff water flows along the inside of the downpipe and reaches the annular space filled with filter material between the inner pipe and the outer pipe. The flow rate can be selected so the amount of normal rainfall is collected without problems. In the event of heavy rainfall, the excess water can be easily drained off via the inner pipe. Internal research has shown that such roof runoff water only contains low metal concentrations in such cases, which can be drained off unfiltered without objections. The inner pipe also allows leaves and sticks to be easily removed through the inner pipe to the sewerage system in the event of heavy rainfall. 
     One advantageous property of the filter material is that it can run dry after a rain event. Drying out of the filter has no effect on the separating performance or metal absorption by the filter material. Rather, drying out of the filter has a certain advantage concerning potential clogging of the filter by dirt particles in the roof runoff water. The fact that such dirt particles are being continuously dried out and thus their consistency is being changed, reduces the risk of clogging. 
     The dimensions of the filter and thus its capacity depend on the outer diameter of the cast iron gutter pipe and on the inner diameter of the inner pipe. In order to reliably prevent clogging by leaves and sticks, the inner diameter of the inner pipe must be at least 30 mm. A maximum inner diameter of 100 mm is adequate. Due to the usual distance of the downpipe to the adjacent building wall and from the esthetic point of view, the outer diameter of the cast iron gutter pipe can be between approximately 100 mm and 250 mm. The height of the filter is between approximately 300 mm and 1800 mm. Within these extremes, the size of the filter is adapted to the conditions of the application, in particular to the surface exposed to rainfall. 
     The filter is preferably designed such that the lower end of the outer pipe is crimped inward. Thus it forms a stop for the inner pipe that is crimped outward at the lower end. The radial dimension of the annular space between the inner pipe and the outer pipe is also determined by a spacer, which is provided at the upper end of the inner pipe. This spacer can be formed by an annular disk, for example, which is attached to the external perimeter of the inner pipe. Such a filter is easy to manufacture and replace. 
     Another arrangement is provided that is preferably used if the surface exposed to precipitation is greater than approximately 160 sq.m. and if the roofing material is mainly made of metal. The collector well is usually at the end of the gutter system below ground surface and has a removable cover. A filter is usually installed in such a collector well so that a compact filter material column is present. This column is arranged at a distance from the inside of the collector well at least in some areas so that this distance is used for overflow. Due to the compact column, this filter is capable of filtering large amounts of roof runoff water. Distance specifications or esthetic considerations do not need to be taken into account, since the collector well has sufficient volume to accommodate the necessary amount of filter material. By modifying the filter cross section surface, it can be adapted to the local metal load and the surface area exposed to precipitation over a broad range. 
     The cover of the collector well allows the filter material to be regularly monitored and replaced as needed. 
     The height of the compact column in the collector well can be between 200 mm and 1000 mm. The diameter of the column is between 100 mm and 600 mm. 
     In order for the roof runoff water supplied to the filter to be distributed over the entire cross section of the compact filter column as evenly as possible, a water distributor is arranged above the filter. This can be a distributor spiral, for example. This prevents roof runoff water from dripping only on a certain area of the filter, which is then rapidly saturated and the filtering performance of the filter drops, although its total capacity is far from being exhausted. 
     Due to the compact design of the filter, there is the danger that dirt and leaves will accumulate on the surface of the filter material and thus clog it. To avoid this problem, a foreign body passage is provided in the lower portion of the gutter system. This foreign body passage can be arranged either directly in the downpipe of the gutter system or directly at the inlet of the collector well. 
     In cases where a rainwater use system is available or at least planned, it is advantageous if the filter is arranged in a container and located downstream from a water storage device located at the lower end of the gutter system with a pump connected between them. Such a water storage device has a capacity of approximately 1500 liters. The roof runoff water goes from the gutter system into the water storage device and is pumped therefrom by the pump into a container equipped with filter material, wherefrom it can be supplied to one or several consumers. 
     According to a further aspect of the invention, the filter material is filled into a pressure vessel. The compact filter material is located in a column at mid-height of the pressure vessel. The roof runoff water is fed under pressure from the water storage device above the filter material, flows through the filter material and reaches, at the bottom of the filter material, the discharge pipe that traverses the filter material, wherefrom it can be supplied to a consumer. 
     It is useful to equip the water storage device with a level control in order to protect the pump from running dry. 
     According to a further aspect of the invention, a foreign body trap is provided upstream from the water storage device, preferably in the downpipe of the gutter system. This trap separates large particles such as leaves, sticks, and dirt, and the roof runoff water thus pre-cleaned is then conducted into the water storage device. Dirty water in an amount of about 10% of the roof runoff water can be drained into the sewerage system without any problem, without causing any relevant environmental pollution. 
     The overflow ensures that no storage problems occur even in the event of large amounts of roof runoff water. 
     According to another aspect of the invention, a suction basket with a suction hose coupled to the pump is provided in the water storage device. This arrangement additionally ensures that no large dirt particles reach the filter material via the pump, causing it to clog. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in detail below with reference to the embodiments illustrated in the drawings. 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                  FIG. 1 
                  schematically shows a vertical section through an 
               
               
                   
                   
                 arrangement for removing heavy metal ions from roof 
               
               
                   
                   
                 runoff water; 
               
               
                   
                 FIG. 2 
                 schematically shows a vertical section through an 
               
               
                   
                   
                 outer pipe for a filter of the arrangement; 
               
               
                   
                 FIG. 3 
                 schematically shows a vertical section through the 
               
               
                   
                   
                 inner pipe of the filter of the arrangement; 
               
               
                   
                 FIG. 4 
                 schematically shows a vertical section through the 
               
               
                   
                   
                 built-in filter of the arrangement; 
               
               
                   
                 FIG. 5 
                 schematically shows a vertical section through 
               
               
                   
                   
                 another embodiment of an arrangement for removing 
               
               
                   
                   
                 heavy metal ions from roof runoff water; and 
               
               
                   
                 FIG. 6 
                 schematically shows a vertical section through a 
               
               
                   
                   
                 third embodiment of an arrangement for removing 
               
               
                   
                   
                 heavy metal ions from roof runoff water. 
               
               
                   
                   
               
             
          
         
       
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In FIG. 1, the downpipe of a gutter system  2  is denoted as  1 . Downpipe  1  is attached using a bracket  3  at a distance from the building wall  4 . 
     The lower end of gutter system  2  is formed by a cast iron gutter pipe  5 , which extends above the ground surface  6 . Downpipe  1  and cast iron gutter pipe  5  are coupled via a cast iron gutter pipe coupling  7 , which can be displaced vertically according to arrow  8 . 
     A filter  9 , illustrated in more detail in FIGS. 2 through 4, for removing heavy metal ions from roof runoff waters is installed in cast iron gutter pipe  5 . Filter  9  is configured as a double-pipe cartridge having inner pipe  10  and outer pipe  11 , as well as filter material  13 , filled into annular space  12  between inner pipe  10  and outer pipe  11 . In this embodiment, filter material  13  is made of natural zeolite. As can be seen in FIG. 2, outer pipe  11  is crimped inward at its bottom end  14 . This forms an annular bottom  15 . According to FIG. 3, inner pipe  10  is crimped outward at its lower end  16 , thus forming outer annular flange  17 . If inner pipe  10  is inserted into outer pipe  11  as FIG. 4 shows, inner pipe  10  is supported by outer pipe  11  and secured at the lower end  16  of annular space  12 . In order to secure annular space  12  at the upper end of inner tube  10 , a spacer  18  in the form of a collar is provided. 
     According to FIG. 4, filter  9  is completely inserted in cast iron gutter pipe  5 ; for this purpose, only cast iron gutter pipe cap  7  must be pushed upward and cast iron gutter pipe  5  must be swivelled away from building wall  4 . 
     In the event of normal rainfall or sleet, the roof runoff water flows on the inside  19  of downpipe  1  and reaches the annular area of filter material  13 . If there are larger amounts of precipitation, they can be drained off via inner space  20  of filter  9 . 
     In the embodiment of FIGS. 1 through 4, a typical roof with about 100 sq.m. surface exposed to precipitation and a metallic portion of approximately 10% of this surface is assumed. In this case, the filter material can be used for approximately four years for a 100 mm diameter downpipe  1  and an outer diameter of filter  9  measuring 150 mm, as well as a height of 1000 mm and approximately 7 kg of filter material  13 . 
     The arrangement illustrated in FIG. 5 for removing heavy metal ions from roof runoff waters is used for filtering rainwater from metal roofs with a surface exposed to precipitation greater than 160 sq.m. 
     Also in this case, downpipe  1  of a gutter system  2  is attached to a building wall  4  using a bracket  3 . At the lower end  21  of downpipe  1  there is a foreign body trap  22 , in particular for sticks and leaves. Cast iron gutter pipe  5  secured at its lower end above ground surface  6  is also coupled with downpipe via a cast iron gutter pipe cap  7 . Cast iron gutter pipe cap  7  can be moved vertically according to arrow  8 . An elbow  23  is attached to cast iron gutter pipe  5 , which leads to a collector well  24  located under ground surface  6  and is connected to sewerage system  25 . A filter  9   a  in the form of a compact column of filter material  13  is arranged in this collector well  24 . A water distributor  26  in the form of a distributor spiral is located above filter material  13 . 
     Collector well  24  has a cover  27 , through which filter material  13  can be maintained and regularly changed within the usual periods. 
     In the arrangement for removing heavy metal ions from roof runoff waters schematically illustrated in FIG. 6, a water storage device  28  is arranged under ground surface  6 . Water storage device  28  is connected to downpipe  1  of a gutter system  2  via inlet  29 . A foreign body trap  31  (not illustrated) is arranged in section  30  of downpipe  1  having an increased diameter. Inlet  29  is located in the upper area of water storage device  28 . Immediately under it overflow  32  of water storage device  28  is connected to gutter system  2 . 
     In addition, in the upper area of water storage area  28  there is a level control  33 . 
     A suction basket  34 , having a suction hose  35  attached, is provided in water storage device  28 ; suction hose  35  is connected to a pipe  36 , which leads to a water pump  37 . A shutoff valve  35  is installed in pipe  36 . Water pump  37  is connected to a pressure vessel  40  via pipe  39 . Shutoff valves  38 , pressure gage  41 , and a check valve  42  are installed in pipe  39 . 
     A filter  9   b , having a column-like compact filter material  13 , is located at mid-height of pressure vessel  40 . Filter material  13  is also traversed by a discharge pipe  43 , which ends under filter  9   b . Via this discharge pipe  43 , provided with shutoff valve  38 , the filtered roof runoff water can be supplied to a consumer V as needed. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Reference Symbols 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                   1 
                 Downpipe of 2 
               
               
                   
                  2 
                 Gutter system 
               
               
                   
                  3 
                 Bracket 
               
               
                   
                  4 
                 Building wall 
               
               
                   
                  5 
                 Cast iron gutter pipe 
               
               
                   
                  6 
                 Ground surface 
               
               
                   
                  7 
                 Cast iron gutter pipe cap 
               
               
                   
                  8 
                 Arrow 
               
               
                   
                  9 
                 Filter 
               
               
                   
                  9a 
                 Filter 
               
               
                   
                  9b 
                 Filter 
               
               
                   
                 10 
                 Inner pipe of 9 
               
               
                   
                 11 
                 Outer pipe of 9 
               
               
                   
                 12 
                 Annular space between 10 and 11 
               
               
                   
                 13 
                 Filter material 
               
               
                   
                 14 
                 Lower end of 11 
               
               
                   
                 15 
                 Bottom of 11 
               
               
                   
                 16 
                 Lower end of 10 
               
               
                   
                 17 
                 Annular flange on 16 
               
               
                   
                 18 
                 Spacer 
               
               
                   
                 19 
                 Inside of 1 
               
               
                   
                 20 
                 Inner space of 9 
               
               
                   
                 21 
                 Lower end of 1 
               
               
                   
                 22 
                 Foreign body trap 
               
               
                   
                 23 
                 Elbow 
               
               
                   
                 24 
                 Collector well 
               
               
                   
                 25 
                 Sewerage system 
               
               
                   
                 26 
                 Water distributor 
               
               
                   
                 27 
                 Cover of 24 
               
               
                   
                 28 
                 Water storage device 
               
               
                   
                 29 
                 Inlet of 28 
               
               
                   
                 30 
                 Section of 1 
               
               
                   
                 31 
                 Foreign body trap 
               
               
                   
                 32 
                 Overflow of 28 
               
               
                   
                 33 
                 Level control 
               
               
                   
                 34 
                 Suction basket 
               
               
                   
                 35 
                 Suction hose 
               
               
                   
                 36 
                 Pipe 
               
               
                   
                 37 
                 Water pump 
               
               
                   
                 38 
                 Shutoff valve 
               
               
                   
                 39 
                 Pipe 
               
               
                   
                 40 
                 Pressure vessel 
               
               
                   
                 41 
                 Pressure gage 
               
               
                   
                 42 
                 Check valve 
               
               
                   
                 43 
                 Drain pipe 
               
               
                   
                 V 
                 Consumer