In various applications and industries, there is often a need to provide for dividing and distributing of liquids. For example, there is often a need to distribute waste liquid, including wastewater and effluent. In particular, systems are sought for dividing the flow of wastewater, effluent, or other liquid into two or more equal aliquots, or other proportions, for distribution to separate outlets. The divided flow is then transferred to, for example, other treatment processes or different leach lines in a leach field. In the field of sewage treatment, such a liquid distribution system for dividing the flow of wastewater, effluent, or other liquid into two or more equal aliquots is referred to as a distribution box or D-box.
Many wastewater and sewage disposal systems are designed to disperse wastewater and/or effluent discharged from a wastewater storage system or septic tank into an absorption field. For example, the effluent discharged from a septic tank is conventionally directed first into a standard effluent distribution box. The distribution box is intended to divide the flow of effluent into separate, reasonably equal quantities of effluent, which then pass through separate discharge pipes for distribution in the absorption field. This division of effluent prevents overloading in a single discharge pipe. Unequal discharge of effluent can result in disproportionately high effluent loading in one of the discharge pipes, which can saturate the soil in one location while other locations receive only minimal effluent.
Conventionally, distribution boxes have one singular sump, relying exclusively on the inherent characteristics of liquids to seek their own level and divide themselves into separate flows by means of a number of discharge pipes connected to the singular sump. Each discharge pipe directs an allocated portion of the effluent into different locations in the absorption field. Each of the discharge pipes in the distribution box are set at the same elevation to encourage distribution of equal quantities of effluent into each of the discharge pipes. If the discharge pipes are set at different elevations, effluent entering the distribution box tends to flow out of the discharge pipe that is located at the lowest elevation in the distribution box, even if the difference in elevation among the discharge pipes is minimal.
Even recognizing the need to maintain the discharge pipes located within the distribution box at the same elevation, it is often difficult to install the discharge pipes perfectly level within the ground. Furthermore, even if the discharge pipes are properly installed so that they are level within the ground, it is often difficult to maintain them in a level position because of settling of the ground and other naturally occurring events. For example, components such as septic tanks, distribution boxes, interconnecting pipes, and leach fields commonly shift shortly after installation due to the settling of backfill in their vicinity. Also, such components sometimes shift when the soil around them heaves or falls due to frost action or due to shrinking or swelling related to changes in moisture content. Foot or vehicular traffic, erosion, earthquakes, and other events can also cause components to shift and move out of level.
A number of distribution systems have been proposed over the years. However, when a distribution box shifts after installation and the outlet pipes are no longer at their intended elevations, conventional systems fail to adequately compensate.
Even those discharge systems previously proposed to solve the problem of equalizing the flow of effluent out of a distribution box require human intervention. In other words, such systems must be monitored, inspected, and adjusted by a person. Due to the potentially severe consequences of disproportionate effluent loading, such monitoring and inspection may be a frequent operation taking considerable time and effort. Accordingly, there remains a need for a liquid distribution system that minimizes or even eliminates the need for human intervention after installation to maintain the intended distribution of liquid.
USPTO Backgrounds
USPTO Backgrounds