Abstract:
Actuated bypass valves for use in swimming pool systems are disclosed. The valves automatically bypasses a swimming pool heating unit except when the heating unit is placed into service. The disclosed valves reduce the energy requirements of the circulation pump when the heating unit is bypassed. The valves comprise a tee-shaped valve body. Flow within the valve body is controlled by a sliding plate which slides relative to a stationary plate, where the sliding plate and the stationary plate each has a plurality of openings. Means for actuating the valves may comprise a 24 VAC solenoid. Minimal travel of the sliding plate is necessary for the valve to open from a minimum flow area to a maximum flow area. Methods for utilizing the disclosed valves are also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus and method for use with swimming pool filtering systems. More particularly, this invention relates to a actuated bypass valve and method of using the same which reduces energy consumption by automatically bypassing a heater unit for a swimming pool when the heater is not in operation. 
     It is known that operating a swimming pool can require a substantial amount of energy. The typical residential swimming pool installation has a filtering unit through which daily flows the total volume of water in the pool. The filtering unit is normally operated for several hours per day and is used in conjunction with chemical treatment, such as chlorination, to maintain the clarity and cleanliness of the water. The pool may also have a spa connected to it. If the user desires the pool and/or spa to have heated water, a heater unit is connected to the filtering unit. 
     A heater unit typically utilizes a heat exchanger comprising a tube bundle through which the water flows and a heat source adjacent to the tube bundle for heat transfer to the circulating water. Because of the relatively small diameter of the tubes of the tube bundle in comparison to other piping within the system, there is a pressure drop across the tube bundle and pumping water through the tube bundle increases the energy demand of the pump motor. A common variety of heater unit has a gas burner as a heat source. The heater will have either a lit gas pilot, or it will have a pilot circuit which is activated when the user desires to ignite the heater with the ignitor controls. Once the user activates the ignitor, a gas supply valve is opened, allowing gas to flow to the burner. A pressure switch is connected to the ignitor controls, which prevents the gas supply valve from opening if there is no pressure in the tube bundle. This feature of the heater unit prevents the gas burner from being activated if there is no water in the tube bundle. Otherwise, the components of the heater unit could be severely damaged. 
     Water is drawn into the filtering unit and pumped through the filtering unit, the heater unit and returned to the pool with a self-priming, single suction, centrifugal type pump. A pump motor is attached directly to the seal plate of the pump. The pump motor is an open-drip proof type, capacitor start/induction run design or capacitor start/capacitor run design. Perhaps the most commonly used motor is a single phase, 60 HZ, 3450 RPM motor operating on either a 115 VAC or 230 VAC circuit. 
     Water may be drawn into the pump inlet from several sources. The water may come from the pool skimmer, which cleans floating debris from the surface of the water. The water may also come from a submerged drain in either the pool or spa. The water may also come from a suction vacuum which, powered by water drawn through the unit from the pump suction, travels over the submerged surfaces of the swimming pool and collects debris such as leaves, dirt, and twigs which may accumulate at the bottom and side walls of the pool. The larger debris collected by the suction vacuum, including leaves and twigs, are typically accumulated in an in-line collection basket upstream of the pump suction. Suspended debris, such as suspended dirt and silt, is collected in the filtering medium of the filtering unit. 
     It has long been recognized that energy consumption by swimming pools can be substantial and efforts have been made to develop equipment and procedures which increase the efficiency of the pool cleaning and circulation system and decrease the required energy demand. One known way of reducing energy demand is bypassing a heater unit when the heater is not in operation. When a heater is installed on a pool and/or spa, the pump will lose approximately 15 to 20% of its flow capacity due to water circulation through the small diameter tubes of the tube bundle of the heat exchanger of the heater unit. The reduction in flow capacity can increase the energy demand of the pump motor in two different ways. First, because all of the water in a swimming pool should be filtered on a daily basis, the pump must run longer if the flow rate is decreased. Second, the change in flow rate may cause the pump to operate at less than its optimal efficiency, thereby increasing the amount of energy required to operate the pump. 
     In this regard, it is known to insert a manual bypass valve so that water discharged from the filter outlet may bypass the heater unit and go directly into the return line to the pool. With the installation of the manual bypass valve, if the user does not desire to use the heater unit, the valve may be opened, eliminating the flow restriction caused by the tube bundle of the heater unit. When the user desires to use the heater unit to heat either the pool or the spa, the valve is closed so that all water is directed from the filter outlet into the heater unit. 
     In order to maximize energy savings, the manual bypass must be opened whenever the heater is not in use, and only closed when use of the heater is desired. The repeated opening and closing of the manual bypass is inconvenient for the user and often forgotten. Because of the long periods which may pass between demand for use of the heater unit to heat the pool or spa, it is not uncommon for a user to forget the system is in bypass mode when attempting to start the heater for the first time after a prolonged period of non-use. The user will attempt to ignite the heater, but because there is no water flow in the tube bundle, the pressure switch prevents gas flow to the burner. Users will frequently call pool service companies believing there is something wrong with the heater, when in fact it is only necessary to shut the bypass valve. 
     There is a need for a bypass valve which is normally open, when the heater unit is not in operation, but which automatically diverts fluid flow to the heater when the heater unit is activated, without the user having to manually open or close the bypass valve. It is desirable that such an automated bypass valve be inexpensive to purchase and repair and of simple design. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an apparatus and method for reducing swimming pool energy consumption, meeting the needs identified above. 
     An actuated valve for reducing swimming pool energy consumption is disclosed. The valve comprises a tee-shaped valve body, where the body has a first axis defined by a first leg and a second leg opposite the first leg. A second axis is defined by a third leg, where the third leg is perpendicular to the first leg and second leg and the second axis is perpendicular to the first axis. An inlet is formed by the first leg of the tee and an outlet is formed by the second leg of the tee. A stationary plate is attached within the valve body with attachment means. The stationary plate has a first face, where the first face has a plurality of openings. The stationary plate is attached within the valve body such that the first face is perpendicular to the first axis and parallel to the second axis. A sliding plate is slideably attached within the valve body such that the sliding plate is parallel to and abutting the stationary plate. The sliding plate has a second face, where the second face has a plurality of openings. The sliding plate is slideable in the direction of the second axis. A flow area is created by the positioning of the plurality of openings of the second face with respect to the openings of the first face. Actuating means are attached to the sliding plate for sliding the sliding plate in a direction parallel to the second axis. The actuating means are activated by an electrical current, wherein the flow area is decreased when the actuating means is activated. Biasing means are attached to the sliding plate. The biasing means maintain the flow area at a maximum size when the actuating means is not activated. Sealing means seal off the third leg. 
     Methods of reducing swimming pool energy consumption are also disclosed, the methods comprising steps for utilizing embodiments of the disclosed valve. 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a perspective view of the disclosed automated bypass valve. 
     FIG. 2 shows a side view of the disclosed automated bypass valve. 
     FIG. 3 shows a view facing the inlet of the disclosed valve. 
     FIG. 4 shows a top view of the disclosed valve. 
     FIG. 5 shows a sectional view along line  5 — 5  of FIG.  4 . 
     FIG. 6A shows a sectional view along line  6 — 6  of FIG. 4, when the valve is in a first open position. 
     FIG. 6B shows a sectional view along line  6 — 6  of FIG. 4, when the valve is in a second closed position. 
     FIG. 7 is a schematic of a pump, filter and heater unit of a swimming pool, showing a possible placement of the disclosed valve. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring now specifically to the drawings, FIGS. 1 through 4 show the exterior components of the disclosed actuated bypass valve  10 . The valve  10  generally comprises a tee-shaped valve body  12 , where the body  12  has a first axis A defined by a first leg  14  and a second leg  16  opposite the first leg. A second axis B is defined by a third leg  18 , where the third leg is perpendicular to the first leg  14  and the second leg  16  and the second axis B is perpendicular to the first axis A. An inlet  20  is formed by the first leg  14  of the tee and an outlet  22  is formed by the second leg  16  of the tee. In its most simple form, valve body  12  may be formed from a PVC Tee. For application in a residential pool environment, a PVC Tee in a size ranging from 2 inches to 3 inches may be used. 
     A stationary plate  24  is attached within the valve body  12  with attachment means, such as plate supports  26 . Plate supports  26  may be glued or otherwise attached within the valve body  12 , or the plate supports may be formed as an integral part of the valve body  12  if the valve body is cast or manufactured by an injection mold process. 
     The stationary plate  24  has a first face  28 , where the first face has a first plurality of openings  30 . The stationary plate  24  is attached within the valve body  12  such that the first face  28  is perpendicular to the first axis A and parallel to the second axis B. A sliding plate  32  is slideably attached within the valve body  12  such that the sliding plate  32  is parallel to and abutting the stationary plate  24 . The sliding plate  32  has a second face  34 , where the second face has a second plurality of openings  36 . The sliding plate  32  also has a top end  33  and a bottom end  35 . The sliding plate  32  is guided and laterally retained by plate guides  37 , which may be glued or otherwise attached within the valve body  12 , or the plate guides may be formed as an integral part of the valve body if the valve body is cast or manufactured by an injection mold process. 
     The sliding plate  32  is slideable in the direction of the second axis B. A flow area is created by the positioning of the second plurality of openings  36  of the second face  34  with respect to the openings  30  of the first face  28 . Actuating means, such as a solenoid  38  combined with an operating rod  40  are attached to the sliding plate  32  for sliding the sliding plate in a direction parallel to the second axis B. The operating rod  40  may be bonded to the plunger of the solenoid using known adhesives, or an integral plunger/operating rod may be implemented. The solenoid  38  may be attached to cap  44 , which acts as sealing means for sealing off the third leg  18 . 
     The actuating means are activated by an electrical current, such that the flow area is decreased when the actuating means is activated. An acceptable solenoid  38  is model number 701-24AB2C available from Industrial Plastic Valves Company of Carson City, Nev. This solenoid uses a series 701 solenoid coil, operating at 24 VAC. Many 24 VAC solenoids are acceptable, including those which are sold off-the-shelf at many facilities for use with automatic irrigation and sprinkler systems. The 24 VAC solenoid is desirable, because the voltage to the pressure switch of most heater units is 24 VAC, although the input voltage to the controls of a heater unit is commonly 120 or 240 VAC. 
     It is to be appreciated that the flow area of the disclosed valve is adjusted by the relative position of the sliding plate  32  with respect to the stationary plate  24 , because adjusting the relative position of the sliding plate with respect to the stationary plate changes the respective arrangements of the first plurality of openings  30  of the first face  28  of the stationary plate  24  with respect to the second plurality of openings  36  of the second face  34 . The more the openings  36  of the sliding plate  32  line up with the openings  30  of the stationary plate  24 , the larger the flow area. 
     In one embodiment of the valve  10 , the dimensions of the stationary plate  24  may be equivalent to the dimensions of the sliding plate  32 , and the pattern of the first plurality of openings  30  of the first face  28  may match the pattern of the second plurality of openings  36  of the second face  34 , as shown in FIGS. 3,  6 A and  6 B. In these figures, the first plurality of openings  30  and the second plurality of openings  36  may comprise a series of slots and holes. It has been found for a 2″ valve body that a maximum flow area of 1.76 square inches works well. It is to be appreciated that for the valve shown in FIGS. 3,  6 A and  6 B, a very small movement of sliding plate  32  along axis B results in the valve being either fully open or fully closed. Such minimal travel is desirable because the plunger of solenoid  38  generally has limited travel, approximately ⅛″ to ¼″. 
     Biasing means, such as a spring  42  are attached to the sliding plate  32  and the valve body  12 . The biasing means maintain the flow area at a maximum size when the actuating means is not activated, where the biasing means retains the sliding plate in a first open position along the second axis. In this first open position of the sliding plate  32 , the second plurality of openings  36  of the second face  34  are in facing relation with the first plurality of openings  30  of the first face  28 . When the actuating means are activated, the sliding plate  32  may be placed in a second closed position wherein the second plurality of openings  36  of the second face  34  are in facing relation to portions of the first face  28  having no openings. Therefore, the sliding plate  32  is retained in the first open position except when the actuating means are activated. As shown in FIG. 5, an adjustment screw  45  may be inserted through valve body  12 , so that the tip of the adjustment screw engages sliding plate  32 . The adjustment screw allows the user to manually adjust the amount of bypass. 
     Unlike most other valves, the disclosed actuated valve  10  is designed so that even in the fully closed position, a certain amount of bypass is allowed through the valve. The valve described herein is not one which requires a positive seal in the bypass valve. Water will begin to flow through the tube bundle of the heater unit once the flow area of the valve has been restricted such that the head required to pump through the bypass valve is equivalent to the head required to pump through the tube bundle. Further closing of the bypass valve will result in greater flow through the heater unit. However, the bypass valve is intended to allow a bypass of approximately 20% even when the valve is in the “closed position.” Because solenoid  38  must be energized for the valve  10  to be in a “closed” position, the bypassing liquid serves to cool the solenoid. 
     A method of using the disclosed actuated bypass valve is also disclosed. A “swimming pool system” may be thought of as the swimming pool itself, plus means for filtering and heating the water. A schematic of the means for filtering and heating the water is depicted in FIG.  7 . The swimming pool system will have at least one suction line  46  from the pool to the suction end of a pump  48 . A filter  50  for removing particulate matter from the pool water has an inlet  52  and an outlet  54 , where the inlet is connected to the discharge side of the pump  48 . The filter outlet  54  is connected to a heater unit  56 . The heater unit  56  has an outlet  58  connected to a return line  60  for returning filtered water to the pool. The heater unit  56  has an electrical switch or control  62  which activates a valve for directing gas to the heater burner, which heats water circulating in a tube bundle adjacent to the heater burner. For this type of swimming pool system, a method is disclosed for reducing swimming pool energy consumption. The method comprises the steps of connecting a bypass line  64  from the filter outlet  54  to the return line  60  to allow bypassing the heater unit  56 . An embodiment of the actuated valve  10  disclosed herein is installed in the bypass line  64 , wherein the actuated valve has actuating means, such as solenoid  38 . The electrical switch or control  62  of the heater unit  56  is connected to the actuating means such that the actuating means is activated when the electrical switch is activated. When heated water is desired, the user activates the electrical switch or control  62  of the heater unit  56 , which energizes the actuating means connected to the actuated valve  10 . When the actuating means are energized, the flow area of the actuated valve  10  is reduced to a minimum size and water flows through the tube bundle of the the heater unit  56 , where the water is heated by the heater burner. When heated water is no longer desired, the electrical switch or control  62  of the heater unit  56  is switched off so that gas no longer flows to the heater unit. When the electrical switch or control  62  is switched off, the actuating means of the actuated valve  10  are no longer energized and the flow area of the actuated valve returns to its maximum size, so that the heater units  56  is bypassed once again. The above method may be utilized for each embodiment of the actuated bypass valve disclosed herein. 
     While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the size, shape, and/or material of the various components may be changed as desired. Thus the scope of the invention should not be limited by the specific structures disclosed. Instead the true scope of the invention should be determined by the following claims.