Patent Publication Number: US-6220301-B1

Title: Drainage system

Description:
The present invention relates to a drainage system for a conduit having a conduit inflow and a conduit outflow. 
     Such drainage systems are known and customary in a very wide variety of shapes and designs. In particular, measures are often necessary for water conservation which are frequently much too expensive in terms of manufacture. For example, the authorities require retaining basins to protect outfalls, i.e. streams, rivers and lakes. 
     In addition, there is a need for action when newly built areas are developed if conduits in the old area of a town are overloaded. In particular unsealing and drainage are rarely adequate so that either buffer basins have to be constructed or lengths of conduit have to be replaced in order to protect the older parts of the town. 
     In addition, conventional drainage systems can usually only be regulated and directed at considerable expense, are expensive to maintain and are therefore associated with extremely high operating costs. In addition, the intention is in particular to improve the environmental protection while reducing the volume of the basins and, in particular, that of the conduits. In addition, there is to be a saving or reduction in investment costs. 
     The present invention is therefore based on the object of providing a drainage system which overcomes the abovementioned disadvantages and with which a large stream of combined sewage can be slowed down in an easy and cost-effective way, for example when there is heavy rain, the intention being to avoid discharge peaks. 
     In addition, floods are to be prevented and the operation of sewage treatment plants therefore optimized. In addition, the intention is that it will be possible to use such a drainage system in conventional conduit systems and/or retrofitted into conventional conduit systems while reducing the costs associated with installation, manufacture and maintenance. 
     The fact that at least one drainage obstacle which can be moved in the direction of flow is provided for limiting, directing, regulating or influencing a stream of water leads to this object being achieved. 
     In the present invention, a drainage obstacle according to the invention can be introduced into a conventional conduit. Preferably, two drainage obstacles, arranged one opposite the other, are introduced into a conduit. Said obstacles can be moved in an articulated fashion and in the direction of flow, in particular they can be pivoted on conduit walls, in particular secured to an inner wall of the conduit. They are held in a horizontal position with respect to the conduit wall by an energy accumulator element. 
     A gap is preferably formed between a drainage obstacle and the inner wall or between two adjacent drainage obstacles which are located one opposite the other. Said gap can also be dispensed within a closed position of rest. 
     A bottom outlet with, if appropriate, a drain which is let into a base in a countersunk fashion may also be provided underneath the drainage obstacle. An overflow may also be provided above an upper edge of the drainage obstacle in the conduit. 
     In the present invention, water flows into a prechamber of the conduit, and when there are very large quantities of water or mass flow rates, the level in the prechamber, and/or upstream of the drainage obstacle, rises very quickly. As a result, high pressure forces act on the drainage obstacle, which then yield to the pressure forces and correspondingly open a gap which may be formed. In this context, the gap may be enlarged in order to conduct onward the desired quantities of water so that, as far as possible, there is no overflow over the threshold. This system preferably operates in a purely mechanical way and can also be regulated in a purely mechanical way. 
     This serves essentially to reduce and absorb peak loads. Particularly in the case of rain events, the effect of the drainage obstacles is utilized in a selective fashion to dam up water. This serves as a brake on the drainage. Such drainage systems, in particular drainage obstacles, can be used as systems whose length is divided into sections or which are even in the form of a cascade. They are also suitable, in particular, for installation in previously existing shafts or conduits. 
     A calculated discharge is conducted onward, for example, to the next mount, via the bottom outlet between the base and at least one drainage obstacle. As rain increases, damming up occurs upstream of the at least one drainage obstacle. The substances contained in the water are precipitated and are conveyed to the sewage treatment part by the bottom current via the drain or via the bottom outlet. 
     Thus, a coarse separation of the combined sewage from impurities or pollutant loading can also be performed so that the rise in water mass is free of them. As a result, the quantity of water which is relieved by the opening of the drainage obstacle under the effect of pressure has less pollutant loading, which also leads to a reduction in the peaks. Overloaded conduits can therefore convey the quantity of water whose drainage is delayed. 
     It is not necessary to replace the conduits, and the volumes of new basins can be correspondingly reduced. 
     This drainage system can be configured by means of conduit network calculation and the dimensions of the drainage obstacles can correspondingly be determined precisely by such calculations. 
     In particular, optimizing wastewater systems by activating retention spaces in sewage systems and delaying drainage by the use of the drainage system according to the invention enables both existing and also new conduits to be utilized, while drainage peaks are reduced and discharges are slowed down. 
     In addition, floods can be avoided, while adjoining sewage treatment operations can also be optimized. 
     The complete conduit network can be operated in purely mechanical terms as a sponge in a very cost-effective way requiring little maintenance. In addition, such a drainage system can be retrofitted into any shaft and is particularly easy to regulate. The frequency of flooding can be minimized and as a result the loading of outfalls can be reduced. 
    
    
     Further advantages, features and details of the invention emerge from the following description of preferred exemplary embodiments and with reference to the drawing, in which: 
     FIG. 1 shows a schematically illustrated plan view of a drainage system for a conduit; 
     FIG. 2 shows a cross section through the drainage system, in particular through the conduit according to FIG. 1 along the line II—II; 
     FIG. 3 shows a schematically illustrated plan view of a drainage system for a conduit according to FIG. 1 as a further exemplary embodiment; 
     FIG. 4 shows a schematically illustrated cross section through the drainage system, in particular through the conduit according to FIG. 3 along the line III—III. 
    
    
     According to FIG. 1, a drainage system R 1  according to the invention has a conduit  1  which is formed from lateral conduit walls  2 . At the ends, the conduit  1  can be closed off by means of end walls  3 . However, a conduit  1  which is open at the end is also within the scope of the present invention. 
     In cross section, as illustrated in particular in FIG. 2, the conduit  1  is formed from the conduit walls  2  in the manner of a rectangle or square. 
     A base  4  forms a lower boundary, a countersunk drain  5  being preferably formed in the center of the base  4 . The base  4  preferably extends in the center, with a slight incline with respect to the drain  5 . The drain  5  may be of square, rectangular or even semicircular design. 
     The water flows in a direction of flow X via a conduit inflow  6  through the conduit  1  to a conduit outflow  7 . Between the conduit inflow  6  and conduit outflow  7 , the conduit  1  is preferably provided with a slight negative gradient. 
     However, it is important in the present invention that at least one drainage obstacle  8 . 1 ,  8 . 2  is introduced in the conduit  1 , such as is apparent, in particular, in FIGS. 1 and 2. The drainage obstacle  8 . 1 ,  8 . 2  is connected in an articulated fashion by means of a joint  9  to an inner wall  10  of the conduit, and is mounted in a pivotable fashion, in particular in the direction of flow X. 
     The drainage obstacle  8 . 1 ,  8 . 2  is preferably formed in the manner of a plate made of symmetrical plate elements on which an energy accumulator element  11 , designed in particular as a pressure spring element, acts in an articulated fashion, preferably at the other end of the joint  9 , and is also connected in an articulated fashion to the inner wall  10  of the conduit wall  2 . 
     In this context, in a position of rest or home position, the energy accumulator element  11  and the plate element of the drainage obstacle  8 . 1  preferably enclose an angle β of approximately 45°. 
     In a position of rest, the drainage obstacles  8 . 1 ,  8 . 2 , in particular their plate elements, lie in a plane E, and are preferably perpendicular to the conduit wall  2  or to the inner wall  10  of the conduit. 
     In this context, a gap  12  is formed through which water can flow, in particular wastewater or the like, which enters the conduit  1  through the conduit inflow  6  in the direction of flow X. The gap is formed between the two drainage obstacles  8 . 1 ,  8 . 2 . 
     If the liquid level rises strongly in a prechamber  13  of the conduit  1 , the pressure on the two drainage obstacles  8 . 1 ,  8 . 2  increases, said drainage obstacles  8 . 1 ,  8 . 2  yielding to the pressure of the masses of water by compression of the energy accumulator element  11 . In this way, the drainage obstacles  8 . 1 ,  8 . 2  are moved in a purely mechanical way in the direction of flow X, with the result that the gap  12  is enlarged. A considerably larger volume flow of water can be moved through this larger gap, with the result that in this way the drainage obstacle  8 . 1 ,  8 . 2  regulates itself automatically. 
     In order to make fine adjustments of a position of rest, a trimming device  14  may be provided, said trimming device  14  limiting the length of the energy accumulator element  11  and in particular the position of the drainage obstacle  8 . 1 ,  8 . 2 . In addition, consideration should be given to changing mechanically the spring stiffness or the spring constant, or even a prestress of the energy accumulator element  11  in order to be able to influence the spring characteristics. 
     The water which flows out through the gap  12  then passes through the conduit  1 , in particular through the conduit outflow  7  to the outside and can be conducted onward there. 
     As is also clear from FIG. 2, an opening is formed underneath a lower edge  15  of the drainage obstacle  8 . 1 ,  8 . 2 , in particular a bottom outlet  16  being formed in the manner of a gap which is of slit-like design. The drain  5  which is let into the base  4  is also associated with the bottom outlet  16 . The bottom outlet  16  can be changed by means of a vertical adjustment of the at least one drainage obstacle  8 . 1  to  8 . 3 . 
     An overflow  18 , which forms an overflow orifice  19 , adjoins an upper edge  17  of the drainage obstacle  8 . 1 ,  8 . 2 . Said overflow orifice serves as an additional protection against the ingress of large amounts of water, but is not used if the drainage system is configured correctly. 
     The water flows at maximum up to the upper edge  17  of the outflow obstacles  8 . 1 ,  8 . 2 . 
     The method of operation of the present exemplary embodiment is as follows: 
     If water, wastewater, rainwater or the like flows into the conduit  1  via the conduit inflow  6 , in the case of small amounts the water is directed through the drain  5 , in particular the dry-weather drain. If the water level rises, it flows through the entirety of the bottom outlet  16  and at least partially through the gap  12 . 
     In the case of strongly rising water, the water can be dammed up in the prechamber  13 , in which case when a certain degree of pressure is applied to the drainage obstacles  8 . 1 ,  8 . 2 , their energy accumulator elements  11  yield in the direction of flow X and pivot upward. 
     As a result, the gap  12  is continuously opened, permitting a relatively large amount of water to flow into the following conduit  1 . As a result, a drainage delay is formed by retention spaces or damming-up spaces. This permits rainwater to be treated. 
     In addition, this reduces drainage peaks, undesired damming up is prevented and it becomes possible to use retention spaces. 
     However, it is also important with the present invention that the quantities of water are controlled and directed and in particular influenced, in a purely mechanical way as a result of the pivoting of the drainage obstacles  8 . 1 ,  8 . 2  under the application of pressure. As a result, such drainage systems R 1  can be manufactured, maintained and regulated very cost-effectively. 
     The intention is that the scope of the present invention will also include the fact that, for example, the energy storage elements  11  can be replaced by torsion spring elements, helical spring elements or the like which can also be arranged in the vicinity of the joints  9 . The intention is that no limit will be placed on the invention in this respect. 
     The present invention also includes the fact that, for example, only a single drainage obstacle  8 . 1 ,  8 . 2  is introduced into the conduit  1  in the manner described above. In this context, the gap  12  can then be formed between the inner wall  10  of the conduit wall  2  and the plate element. The latter can also be given a narrow setting or be preset to any desired width as a basic setting. The method of operation is that described above. 
     In a further exemplary embodiment of the present invention according to FIG. 3, a drainage system R 2  is shown, which is correspondingly constructed in the manner described above. Essentially, details on the individual components will not be given again here. However, there is a difference in that a drainage obstacle  8 . 3  is formed on one side by one of the two conduit walls  2  composed of a plurality of elements  20 . 1  to  20 . 3 . The first element  20 . 1  extends at an angle α of approximately 0° to 90° into the conduit  1 , the element  20 . 1  being positioned at an angle in the direction of flow X. 
     The preferably plate-like element  20 . 1  is adjoined by an arc-like element  20 . 2 . The elements  20 . 1 ,  20 . 2  are connected to one another in an articulated fashion by means of connecting joints  21 . 
     The element  20 . 2  is adjoined by an element  20 . 3  which is formed in a plate-like fashion, is preferably slightly inclined with respect to the conduit wall  2  in the direction of flow, in particular with respect to the inner wall  10  of the conduit, and leads there into a guide rail  22  and is moveably mounted there by means of a roller element  23 . In this context, the roller element  23  may be a wheel, gearwheel or the like. 
     If water, wastewater or the like is then fed to the conduit  1 , a pressure is exerted on the element  20 . 1  which is of planar construction, if the water level in the conduit  1  rises. As a result, the gap  12  which is formed between the element  20 . 2  and the inner wall  10  of the conduit is enlarged in the direction of flow X, as is illustrated by broken lines in FIG. 3, by displacing the drainage obstacle  8 . 3 , in particular by moving one end of the element  20 . 3  in the guide rail  22 . A larger amount of water can flow past. 
     An energy accumulator element  11  can be connected at one end to the element  20 . 3  in the guide rail  22  and can move said element  20 . 3  back into a vertical home position or position of rest if said element  20 . 3  is, for example, designed as a pressure spring. 
     At the other end, the position of the energy accumulator element  11  can be changed in the guide rail  22  by means of a locking device  24 , for example a securable gear, wheel or the like. As a result, it is possible to influence the position of the element  20 . 3 , and in particular to influence prestressing of the energy accumulator element  11 . 
     The scope of the present invention is also to include the fact that two such drainage obstacles  8 . 3  can, in accordance with the exemplary embodiment in FIG. 1, also be arranged located one opposite the other in order to change in the manner described above a gap  12  which is preferably arranged in the center. 
     The idea of the present invention should also include the fact that two drainage obstacles  8 . 1 ,  8 . 2  and  8 . 3  which are located one opposite the other are provided in the conduit  1  and are also arranged outside a common plane E, for example offset in the conduit. 
     FIG. 4 shows a similar cross section corresponding to FIG. 2, the bottom outlet  16  being formed underneath the lower edge  15  of the drainage obstacle  8 . 3 , and the overflow  18  being provided with an overflow orifice  19  above the upper edge  17 . However, the gap  12  is formed between the inner wall  10  of the conduit and the arc-like element  20 . 2 .