WO2012123887A1

WO2012123887A1 - System and method for residential and commercial grey water management

Info

Publication number: WO2012123887A1
Application number: PCT/IB2012/051164
Authority: WO
Inventors: Reinoud Jacob HARTMAN
Original assignee: Idus Controls Ltd.
Priority date: 2011-03-14
Filing date: 2012-03-12
Publication date: 2012-09-20

Abstract

A grey water management system for a domestic residential application and also an irrigation application. The system has a modular pumping station comprising a digital controller and a water pump for pumping grey water to a plurality of consuming devices such as toilet flush water storage tanks. Grey water is collected from the drains of bathroom showers and sinks and stored in a grey water storage tank. A heat exchanger is in the grey water storage tank to transfer heat from the grey water to a hot water tank intake. The digital controller uses a control algorithm which has a learning cycle.

Description

SYSTEM AND METHOD FOR RESIDENTIAL AND COMMERCIAL GREY WATER MANAGEMENT

Technical Field

This invention is related to the field of liquid separation and more particularly relates to a system and method for residential and domestic grey water management comprising a water pumping station adapted to recycle non-potable water for purposes of flushing toilets or for utilizing non-potable water or domestic water for highly efficient irrigation purposes.

Background Art

Water conservation is becoming increasingly important as the cost of treating domestic water increases, demand on local supplies intensifies with population growth, and sources of clean potable water diminish. Global climate change phenomena affecting many areas will intensify this problem, with periods of prolonged drought, intensifying the need to conserve and manage water effectively. In most domestic households, treated potable water is used to flush toilets and water gardens. This is a waste of a valuable commodity. The cost of sewage treatment supplied to home owners increases with water use, as the municipal cost of sewage treatment is proportional to the amount of domestic water consumed. In rural settings, septic tank loading intensifies with the amount of water consumed and well water supplies may be limited by use of well water for toilet flushing and irrigation.

A number of attempts have been made to solve the problem of conserving domestic water. US Patent 4228006 'Domestic Water System' issued to Hanna on October 14, 1980 discloses a system whereby grey water from various in-home sources is directed to a clarifier. Chlorine is added. The water is then reused for non-potable applications. Hanna relies upon the addition of toxic chemicals and does not utilize solar energy for heating grey water as a supplemental source of heat. In addition this invention is not a unit pump station with sophisticated controls and integrated means of performing a number of operations for use and management of grey water in advantageous ways. In US Patent 5406657 'Water Recycling Device for Flush Toilet Use' issued to Donati on April 18, 1995, there is disclosed the use of grey water to supply the toilet tank with flushing water. This system can be retrofitted into existing domestic plumbing systems. The Donati system relies on an external pond to collect rain water. This source can easily become contaminated and turbid and is not suitable for pumping through domestic household pipes. Furthermore, it ignores the opportunity for the advantageous use of grey water from a more reliable source, i.e.- bath and shower water.

Availability of smart modular water conservation systems, lacking in complexity, which can be easily operated by a homeowner with minimal maintenance, create opportunities to gain conservation benefits and allow individuals to make such contributions, while also assisting local authorities in conserving and managing limited water supplies. Many systems that have been proposed are prohibitively complex, require extensive operational maintenance, and are beyond the abilities of the average homeowner to operate as well as lacking a centralized, convenient control and operations system. The modular pumping station described herein solves this problem.

Therefore there is a continued need for a modular pumping station that utilizes grey water from bath and shower sources to satisfy household toilet-flushing demands and can also take advantage of available solar energy to maintain a readily available source of grey water at a suitable temperature for indoor use. Furthermore, there is a need to capitalize on opportunities for energy collection via integration of grey water and solar heat recovery systems.

In addition, there is a need for a modular water pumping station that utilizes rainwater or domestic water for highly efficient automated irrigation with a unique algorithm that maintains soil moisture at a preset level, effectively conserving water, increasing usefulness of storage reservoirs and cisterns, and managing irrigation based on changing requirements as fluctuations in temperature and rainfall alter daily conditions in soil moisture content. Furthermore, there is a need for an easy and practicable modular system that performs these functions for the homeowner in an intelligent and automated way. Providing effective water conservation technology in a form that can be readily operated by homeowners fosters conservation on an individual basis, while also meeting the needs of city and municipal authorities, many of which, who face ever-increasing water supply and conservation challenges.

Technical Problem

Summary of the Invention

My invention is a grey water management system comprising a modular pumping station comprising a digital controller, a water pump for pumping demand water through a demand water supply system to a plurality of grey water consuming devices. The water pump has a suction in communication with a volume of grey water stored in a grey water storage tank which collects and stores a predetermined volume grey water from a plurality of grey water drains. The water pump has an outlet which is connected to a plurality of devices for consuming grey water. Included in the system is a normally closed first valve disposed between the grey water storage tank and a domestic water system for replenishing the contents of the grey water storage tank upon demand. There is also a normally closed second valve disposed between the grey water storage tank and a sewer drain for draining the grey water storage tank to a sewer drain on demand. A pressure switch is logically connected to the water pump and activates the water pump upon a drop in water pressure in the demand water supply system which might occur if someone were to flush a toilet and place a demand on system to fill the flush tank with grey water.

In one embodiment of the invention there is a heat transfer device disposed within the grey water storage tank and submersed within the volume of grey water. Since the grey water comes from shower drains and bathroom sink drains the volume of grey water contains a quantity of residual heat energy. The heat transfer device transfers this quantity of residual heat energy from the volume of grey water to a hot water tank by way of a connection to the hot water tank domestic cold water supply line. In this way, waste heat is recovered and put to use preheating cold water prior to it entering the hot water tank.

The heat transfer device comprises a heat sink having a first side and a second side. The first side is fixed to a first heat exchange coil and the second side is fixed to a second heat exchange coil so that heat is transferred from the first heat exchange coil to the second exchange coil through the heat sink which is typically a copper sheet.

The first heat exchange coil is in communication with a solar hot water heater and the second heat exchanger is in communication with the hot water tank.

In another embodiment of the invention, the water pump comprises a 12VDC pump motor which is powered by one of a 120 VAC source through a transformer, a 12VDC battery and a 12VDC solar electrical panel.

In yet another embodiment of the invention the digital controller comprises a memory device and a microprocessor having a software program having a control algorithm sensitive to a plurality of input signals comprising at least the following input signals: a water pump on signal, a water pump off signal, a demand water supply pressure signal, a water pump power draw signal, a 12VDC battery voltage signal and at least one operator input signal. The the control algorithm provides a plurality of output control signals comprising at least the following signals: a pump shutdown signal, a first and second valve open and close signal and a battery charge signal.

The digital controller opens the normally closed second valve to initiate a sewer drain on a 72 hour cycle.

The digital controller includes a grey water storage tank flush cycle following the sewer drain to clean sludge and other detritus from the bottom of the grey water storage tank.

The grey water storage tank flush cycle is initiated by the digital controller by opening the normally closed first valve and permitting a predetermined amount of domestic make-up water to enter and flush the grey water storage tank.

If the grey water tank is empty or if the pump suction is otherwise no longer in communication with the volume of grey water in the grey water storage tank the digital controller opens the normally closed first valve upon receipt of a water pump power draw signal exceeding a predetermined amperage.

The pump shutdown signal is initiated when the water pump operates for a period of time longer than a predetermined period of time.

The plurality of grey water drains comprise only shower and bath drains.

The plurality of devices consuming grey water comprise only toilet flush tanks.

The invention may also include a water filtration device to filter the volume of grey water on a predetermined cycle and/or a water purification device to purify the volume of grey water on said predetermined cycle.

In a further embodiment of the invention there is provided a heat transfer device disposed within the grey water storage tank and submersed within the volume of grey water. The volume of grey water contains a quantity of residual heat energy derived from the plurality of grey water drains and the heat transfer device transfers this quantity of residual heat energy from the volume of grey water to a hot water tank.

The control algorithm may further includes a learning cycle sensitive to a frequency and a time of toilet flushing, and the timing of the opening and the closing of the first and second valves and the timing of a plurality of grey water storage tank draining refilling events so that the control device can adjust to system water use patterns on an unsupervised basis.

The invention has domestic residence configuration as well as an irrigation application.

Technical Solution

My invention is a water pumping station which has a unique grey water system control algorithm which enables a process of intelligently managing a grey water storage tank, such that the grey water may be retained, utilized in discharged in an advantageous manner to flush domestic toilets with resultant significant savings of potable water. This invention further allows integration with a solar energy collector in fluid communication with stored grey water or domestic cold water via a heat exchange unit, whereby solar energy can be used to pre-heat cold water supplying a domestic water heater. A modification of the design of the water pumping station and a unique water system control algorithm allows it to be used to manage rainwater or stored domestic water for irrigation purposes. In that configuration the control algorithm, in combination with a moisture sensor, allows the pumping station to precisely regulate the soil moisture content at a 'just like that' set-point, watering when needed and remaining dormant when watering is not required.

An important element of the design of my invention is that it can be adapted for domestic or irrigation applications utilizing the same modular pumping station with specific control algorithms for each programmed into the same controller, making it a highly versatile device capable of performing a number of functions.

An algorithm-driven modular water pump station is used, enabling the beneficial storage and discharge of non-potable water for domestic toilet flushing and irrigation applications. In the domestic configuration, a low-voltage free-standing pump station whose electronic controller has a unique Grey Water System Control Algorithm is used, which enables a process of managing a grey water storage tank such that the grey water may be retained, utilized and discharged in an advantageous manner. The pump station manages the grey water flow in a way that is advantageous for flushing toilets with resultant savings in daily consumption of potable water. Domestic water can also be used to replenish the grey water tank. The system is controlled by an electronic controller using normally-closed low voltage solenoid valves and a pressure switch-activated pump. The invention may include a solar heating circuit, a heat exchanger for capturing solar energy in grey water, a means of storing heat from said grey water in a storage tank and for transferring said heat to a domestic hot water heating system.

A variation in the design of the modular non-potable water pump station allows it to be used in an irrigation configuration. In this mode, utilizing water collected in a tank or cistern, the free-standing pump station employs an electronic controller utilizing a unique Irrigation Water System Control Algorithm, which, in combination with daylight and moisture sensor information, maintains soil moisture at a desired set-point, watering efficiently and only as needed, with resultant significant water use savings and increased plant health and production. Domestic water may also be used to replenish the tank or cistern, to maintain irrigation during dry periods when other water sources are unavailable.

This variation provides for the effective conservation of water, allowing irrigation in a highly efficient automated manner, utilizing stored water when available, with administration of only the quantity of water needed to achieve desired soil moisture settings, eliminating over-watering and resultant waste of water.

In the domestic configuration of the invention for managing grey water for flushing toilets, the modular pumping station consists of a galvanized steel housing which contains a pressure-switch activated low voltage pump, a 12 volt DC battery, a low voltage electric solenoid valve which operates in the normally closed position, a power supply transformer that reduces 110 V AC line voltage to 12 volts output, an electronic controller circuit board, a switch and related control buttons, and appropriate plumbing and electrical connections. For purposes of reduction of noise and vibration in a domestic setting, the pump is mounted on brackets and suspended by springs, with the pump riding on spiral wire-cored flexible plastic piping affixed to the input and output ports on the pump chamber. In this configuration the springs and flexible piping absorb vibration and prevent its transfer to the pump housing, thus reducing noise within the dwelling. The battery retention bracket, electronic controller board mounting bracket, and switch/control button support are constructed of electro-galvanized 16 ga steel, secured to the housing back plane with suitable stainless steel fasteners. A manifold inserted in the base of the pump station housing consists of plastic plumbing fittings affixed to a normally-closed low voltage solenoid valve. This valve, when activated by the control algorithm of the controller, allows water to be diverted from a storage tank (described below) to sewer, for purposes of emptying the storage tank periodically, and thus maintaining its water quality. Alternately, said water in the storage tank can be re-circulated through a water treatment device, for purposes of maintaining water quality. In the normally-closed position, the solenoid valve allows water to flow from the storage tank, via the pump, to toilets for purposes of flushing them. A powder-coated protective aluminium shroud encloses the unit.

In the domestic configuration, my invention is typically connected to a vented storage tank which receives grey water by gravity and a fluid connection via grey water piping to bath and shower units in the home (Figure- 1). Standard plumbing connections to the grey water storage tank allow it to be drained to sewer, flushed or re-circulated to treatment periodically to maintain water quality, and refilled with potable water, via an air gap, should insufficient grey water reach it from the bath or shower sources. A low voltage normally-closed solenoid valve, in liquid communication with the dwelling's domestic water supply, is externally mounted adjacent to the pumping station and connected electrically to it for control purposes. As required when the supply of grey water in the storage tank is low and the pump senses a lack of water supply, the control algorithm opens this external solenoid valve and admits a timed pulse of make-up water to the storage tank.

In one example of the invention, a roof-mounted solar collector, in fluid connection with a heat exchanger in the grey water storage tank, transfers heat to the grey water . This grey water, in fluid connection to a domestic hot water heater via a heat exchanger, transfers heat to water entering the hot water heater, avoiding the necessity of supplying the hot water heater with only cold water at the input stage and improving the energy efficiency of the dwelling. Heat is also transferred directly from the re-circulating solar heating fluid by conductivity across the copper plating of the heat exchanger to cold potable water circulating in the heat exchanger.

The domestic configuration of the water pump station operates using an intelligent control algorithm via the electronic controller. When a toilet is flushed, the pressure switch-activated pump senses a pressure drop, turns on, and is monitored by the controller. The pump in fluid communication with stored shower or bath grey water in the grey water storage tank, pumps grey water to the toilet to refill the toilet tank. Should there be insufficient water in the tank, the control algorithm, which monitors the amperage draw of the pump, notes the current drop and opens the external solenoid valve and adds a timed pulse of domestic water discharged to the tank via the air gap. Every 72 hours, if the tank has not been previously emptied by toilet flushing, the control algorithm, by opening the purge solenoid valve housed within the water pump station and thus activating the pump, purges the tank to maintain its water quality and prevent it becoming stale. Alternately, if a water treatment device such as a filtration system or ultra-violet system is present in an optional configuration, the controller periodically opens the purge valve, activating the pump, which re-cycles water through the treatment device and from it, back to the storage tank, thus maintaining water quality.

Timing sequences, pressure settings, power draw requirements of the pump motor, battery voltage and operational information received by the controller according to the control algorithm allow it to operate efficiently and also maintain the low voltage battery in good operating condition. Visual signals (red and green LED's) and sound emissions from the controller provide operator information on normal operation, pump cycling, make-up water faults, pump cycle problems, leaks in the system or toilet tanks, or voltage errors. Catastrophic failure, such as breakage of a toilet tank and flooding of the house, is prevented by the control algorithm which shuts down the system when a toilet continues to demand water and the pump continues to run in response, beyond a specified length of time.

In the irrigation configuration the water pumping station components housed within the station are typically configured slightly differently from the domestic grey water configuration. Unless desired by the user, suspension of the pump on spring brackets and springs for pump noise reduction is not required. A bracket is installed within the housing to support the power supply transformer to protect it from the elements and the make-up water solenoid valve is contained within the housing instead of being externally mounted. A hole in the protective shroud with a weather-tight clear plastic window permits light to enter the unit adjacent to a photocell located on the controller, which allows the controller to receive information on day and night and initiate system function after dawn on a daily basis.

In a typical installation the irrigation water pump station is connected to a rain storage tank or cistern by fluid connection so that water in the storage tank is pumped by the water pump station to an irrigation system installed in the garden or plot to be irrigated. Fluid connections from the domestic water supply to an air gap (mandatory to prevent back flow and contamination of domestic water) controlled by the controller and internal make-up water solenoid valve allow the storage tank to be refilled if insufficient rainwater has been accumulated in the storage tank. Optional debris strainers to keep rainwater clean, a pressure tank to smooth the flow to the irrigation system and a solar panel power supply can be used to augment the system.

The irrigation water pump station operates using a unique control algorithm that utilizes information received from a moisture sensor, photocell inputs, pump performance assessed by amperage draw, voltage and timing information to effect control. On initial start-up of the system the moisture sensor is inserted in compacted soil from the plot to be irrigated with the soil moisture level selected by the system operator (the 'just like that' setting) as the initial set-point calibration setting for subsequent irrigation sessions. Each day, in communication with the photocell daylight sensor and the moisture sensor, the controller manages irrigation utilizing the control algorithm which also integrates information on past watering history (for storage-tank water make-up) as well as providing sufficient water to maintain soil water levels while not over-watering the plot. Additional elements of the control algorithm and manual interface allow the operator to adjust the irrigation set-point up and down, re-calibrate the system to a new initial 'just like that' set-point, as well as operate an audible tone for operator information and signalling controller response to control commands. In addition, the control algorithm monitors battery voltage, administers efficient pulse charging of the battery, or automatically senses and utilizes an optional solar cell instead of a plug-in power supply transformer if required.

Advantageous Effects

Several objects and advantages of the invention in the domestic grey water application are to:

save domestic treated water by diverting away from non-potable uses;

recycle and store grey water for non-potable uses;

recover heat from solar energy, transfer it to stored grey water and utilize the heat from stored grey water to augment domestic water heating in a dwelling;

recover heat from solar energy, transfer it directly by conductivity to cold potable water and utilize said heat to augment domestic water heating in a dwelling;

reduce municipal water use by reducing the daily water consumption of dwellings by using bath and shower water to flush toilets, thus saving around 30% of daily indoor water use in a typical dwelling;

reduce municipal sewer loading and resultant infrastructure requirements and treatment costs by reducing discharge to sewer from a typical dwelling by around 30% on a daily basis;

reduce domestic septic system loading in rural areas lacking municipal sewage systems by about 30 % for a typical dwelling;

reduce domestic well water and other water use in locations where water supplies are limited;

provide a modular, all-in-one system for new construction or retrofitted dwellings utilizing standard plumbing fittings which can be installed in a code-compliant fashion;

utilize low voltage components and an optional solar power source with resultant energy savings;

protect the dwelling from catastrophic damage in the event of rupture of a toilet tank or toilet water supply as the invention will shut down the water flow in those areas if a leak or rupture occurs and signal alarm to the operator.

save potable treated water or other sources of water by enabling the use of stored rain-water for irrigation purposes with significant advantages, particularly during summer peak-demand periods;

control irrigation in such a way as to achieve the maximum efficiency in use of water and prevent over watering;

recycle and store rain water for non-potable uses;

augment the supply of stored rain water with domestic or other water sources when needed, refilling the storage tank in only such a manner as to not displace potentially stored rainwater;

provide precise control of the moisture level in the plot to be irrigated, to achieve a 'just like that' soil moisture set-point as established by the operator in keeping with the location of the plot and the unique characteristics of the soil;

provide a range of control settings whereby the set-point soil moisture calibration can be adjusted upwards or downwards according to operator's preference;

utilize low voltage components and an optional solar power source with resultant savings in energy.

Increased plant health and production as a result of achieving optimal daily watering conditions without over- or under-watering.

Finally, an overall advantage of the invention is that it is versatile and can be used for both domestic grey water re-cycling purposes or for irrigation purposes, utilizing the pump station components for both purposes, by application of a specific unique control algorithm for each function to the program supplied to the system controller.

Further objects and characteristics of the invention will become apparent from a consideration of the ensuing description and drawings.

Description of Drawings

Figure 1 is a schematic diagram of the modular grey water pumping station in its domestic configuration for utilizing stored shower and bath grey water for toilet flushing purposes.

Figure 2 illustrates the connections between the pumping station, stored grey water, toilet tanks, storage tank water make-up, and solar energy transfer to grey water and domestic water heating functions.

Figure 3 illustrates details of the heat exchanger submerged in the grey water storage tank for purposes of extracting solar energy from a solar heating device, transferring said heat to stored grey water, and thus to domestic cold water, or directly to domestic cold water.

Figure 4 provides details of the modular pumping station and the noise reduction aspects of the pump mounting.

Figure 5 shows the modular pumping station in its irrigation configuration.

Figure 6 illustrates the logic and control connections in the domestic configuration.

Figure 7 illustrates the logic and control connections in the irrigation configuration.

Best Mode

Mode for Invention

Referring to Figure 1, there is illustrated a generalized schematic drawing of one embodiment of the invention (100) installed within a residential home (102). The system of the invention comprises a grey water storage tank (112) which will be located at the low point in the residence such as the basement. The system of the invention further includes a modular pumping station (110) which is installed proximate to the grey water storage tank (112) and in fluid communication with the grey water storage tank by pipe (124) for pump suction. Pipe (126) allows the storage tank to be pumped to the sewer as required by the controller. Pipe (108) is in communication with the pump outlet and the grey water loads such as the toilet (106). The modular pumping station (110) is installed in a basement, utility room, or crawl space adjacent to a grey water storage tank (112). Grey water is supplied to the tank from bath and shower (104) utilities by pipe (130). The grey water storage tank (112) can be drained (114) to a sewer or recycled to treatment or purification devices. For health and septic reasons it is necessary to keep the quality of grey water high. Power is supplied to the water pumping station via a plug-in transformer (120) connected to the main electrical supply or by an optional solar panel (124) connected to the pump module(110). In this configuration several toilets in a residential unit can be supplied with grey water for toilet flushing purposes. Multiple baths and showers can be connected to the grey water storage tank according to the nature of the domestic facilities in the dwelling.

Referring to Figure 2 there is illustrated in a more detailed drawing another embodiment of the invention (200). The modular pumping station (202) is integrated with a solar heating circuit (204), domestic hot water system (206) and a domestic make-up water supply (224). Here grey water from showers (210) and baths (212) flows (214) by a gravity-driven liquid connection to the grey water storage tank (216). The grey water storage tank is vented (218) and has a sewer connection (220) for draining the tank during maintenance. The grey water storage tank (216) is supplied with make-up water (222) from the domestic water supply (224) to supplement the grey water supply should insufficient water reach the tank from that source. Make-up water enters the system via an air-gap (226) which is a mandatory provision to prevent contamination of the potable water supply with grey water. Make-up water is supplied from the domestic water supply (224) by means of an electronic low voltage solenoid valve (255) controlled by the water pumping station (202). This valve remains in the 'normally closed' position, preventing potable water from entering the air gap (226) supplying the grey water storage tank (216) unless the pumping station controller calls for it, by monitoring the amperage draw on the pump motor. When the grey water storage tank is dry, the pump motor's amperage draw decreases, triggering the controller to call for make-up water according to its control algorithm. Manual isolation valve (230) is normally closed to divert grey water to tank (216).

Still referring to Figure 2, an optional integration of a solar heating circuit (204) and domestic hot water heating system (206) is illustrated as one configuration of the invention. A solar heating panel (240) exposed to sunlight is illustrated in fluid connection (242) with a heat exchanger (244) submerged in the grey water storage tank (216) for purposes of converting solar energy to heat. Within the storage tank (216) heat is transferred from the solar heat transfer fluid in the solar heating circuit (242) by direct conductivity at the heat exchanger surfaces as well as to surrounding grey water via the heat exchanger. Heat is then transferred from the heated grey water to cold domestic water (206) via heat exchange piping on the heat exchanger which is in fluid circulation with a domestic hot water heater (248). The supplemental heat supplied from the heated grey water and by conductivity to the domestic heated water (250) reduces energy requirements and costs for domestic hot water supply to the dwelling.

Referring now to Figure 3 (A to E) there is illustrated the radiating heat exchanger (244) which is installed as an optional configuration of the invention for purposes of keeping the predetermined volume of grey water in the storage tank at a predetermined temperature and transferring solar energy in the form of heat to grey water and to domestic heated water. Heat from the solar energy collector (240- Figure 2) is transferred by circuit 242 to the radiating heat exchanger (244) disposed within the grey water storage tank (216) near bottom (260). The radiating heat exchanger (244) comprises a heat transfer fluid intake (242), a heat transfer fluid discharge (254) and a radiating coil (262) between the transfer intake and discharge. The radiating heat exchanger is adapted to radiate collected solar energy from the re-circulating heat transfer fluid within the heat exchange circuit (242) into the stored water until a desired temperature is achieved. Referring to Figure 3E, the radiating heat exchanger (244) comprises a sheet of copper (270) with the radiating coil (262) on the underside and a domestic water heating coil (272) on the top side of the copper sheet. The coils are fixed to the copper sheet by suitable fixing means such as solder. The copper sheet (270) transfers heat by conduction from the heat transfer coil (262) to the domestic water heating coil (272). The domestic water heating coil (272) has an intake (280) for cold domestic water and a warm water output (282) coupled to conduit (206- Figure 2) into the domestic water heater (248- Figure 2). The tubing used in the heat exchanger is copper but other materials with suitable heat transfer can also be used. The heat transfer fluid is a mixture of propylene glycol/water but any suitable heat transfer fluid can be used.

Still referring to Figure 3, the re-circulating heat transfer fluid is re-circulated by a pump (290). The pump is a two-stage pump capable of operating at a low rate and high rate output. The heat exchange circuit (242) is controlled by a programmable control means (292), comprising temperature sensor (294). The temperature sensor is adapted to determine whether there is a beneficial thermal advantage in re-circulating the heat transfer fluid from the roof to the heat exchanger and if so, thereby elevating the temperature of the heat exchanger and through it, the temperature of the cold water (206) entering the domestic hot water tank (248). The controller (292) can sense a temperature drop in the domestic water supply tubing as it enters (280) the heat exchanger (272) and interprets this as a hot water demand. The controller will then switch from pumping the heat transfer fluid (242) from the low rate to the high rate so as to heat the water as fast as possible.

Figure 4 illustrates one embodiment the modular pumping station (400). The station (400) is built upon an electro-galvanized steel back plane (402) which supports the components and provides a means of attachment to the structure where it is installed. A powder-coated aluminium shroud (removed for clarity and not illustrated) protects the components. A pressure-activated marine low voltage pump (404) propels stored water supplied and discharged by spiral steel coiled plastic pipe suction (406) and discharge hoses (408) crossed below the pump and connected to the system plumbing by plastic plumbing connections. These fluid connections enter and exit the pumping station by means of plastic bulkhead fittings (410). The pump is suspended on four springs from a fixed upper spring bracket (412) connected to a floating lower pump support bracket (414) and as well, rides on the spiral steel coiled plastic pipes (406 and 408) to reduce noise and vibration during operation. Power is supplied by a 12 VDC rechargeable battery (416), housed in a steel battery bracket (418).

Still referring to Figure 4, an assembly consisting of plastic plumbing fittings and a low-voltage normally-closed solenoid valve comprises a solenoid valve manifold (420) mounted in the pumping station. This manifold assembly allows water to be supplied for either flushing toilets or for purging the stored grey water tank according to the direction supplied by the control algorithm. At roughly 72 hour intervals, the controller opens the normally-closed solenoid valve in the solenoid valve manifold (420) and directs the water supplied by the pump to the sewer to flush the storage tank and maintain water quality in the tank. Alternately, in the presence of a water treatment system such as a biological filtration or other water purification system, operated on a different interval as called for by the water treatment system, the controller opens the normally-closed solenoid valve manifold and directs it to re-circulation via the treatment system. Treated water then re-enters the storage tank after treatment. The pumping station houses an electronic control circuit (422) which is programmed with the control algorithm and operated by a switch with 'off' and 'reset' settings mounted in a switch mount (424). A wiring harnesses (not illustrated) connect the various components to the controller and also to a low voltage externally-mounted normally-closed solenoid valve (225- Figure 2) which supplies domestic make-up water to the grey water storage tank through an air gap. Power for battery charging is supplied by an externally-located transformer plugged into an 110 VAC outlet with charging operations managed by the controller utilizing the control algorithm.

Referring now to Figure 5 is a schematic diagram (500) of the modular pumping station (502) in the irrigation configuration. Rainwater is supplied from gutters and down spouts (504) and enters a storage barrel or cistern (506) by fluid connection and gravity flow. Optional leaf and debris strainers can be added to keep the water entering the storage barrel clean (not illustrated). The modular water pumping station (502) is mounted adjacent to the storage barrel (506) and in reasonable proximity to the plot (508) to be irrigated. A moisture sensor (510) is inserted in the soil adjacent to the irrigation emitters (512) and is connected (514) to the controller located inside the modular water pumping station. The pumping station supplies water to the plot via an optional pressure tank (516) which smooths the flow to the irrigation system. When there has been insufficient rain to supply the storage barrel, the controller opens a normally-closed low voltage solenoid valve (410- Figure 4) which supplies domestic make-up water through an air gap. In Figure 5, this valve is illustrated as an external mounting (520) for clarity, however, it is normally contained within the modular pumping station housing. The power supply for the pumping station is provided by either a plug-in transformer (522) or an optional solar panel (524).

The modular pumping station is slightly different in configuration for the irrigation function. As noise reduction is generally not an issue for exterior installations, the pump within the pumping station (502) can be directly mounted to the back plane (402-Figure 4), obviating the need for upper and lower spring and pump brackets and springs. In the irrigation configuration the solenoid valve manifold assembly is not connected to the pump discharge but rather serves to open and close off a supply of domestic water to refill the rainwater storage tank (506) as determined by the controller's control algorithm and information it receives from the pump indicating the rainwater supply is exhausted. In the irrigation configuration an externally-mounted solenoid valve is not required. For the irrigation configuration a small circular window opening is supplied in the pump station's protective shroud adjacent to photocell on the controller module (39) to allow light to reach the daylight sensor as required for the operation of the irrigation control algorithm.

Figure 6 represents control logic linkages (600) between the control regime logic for the domestic grey water toilet flushing configuration utilizing the control algorithm and the components of the domestic system operated by the controller in the water pumping station. On system start-up, the controller (602), utilizing the control algorithm, initiates timers, calibrates sensors, clears system control/error flags, starts the pump (604) and collects information on pump operations. Utilizing the algorithm and amperage draw of the pump, the controller determines if the pump motor is on (604), water is being pumped (608), and records the duration of the pump cycle. When a toilet (610) is flushed, reducing pressure on the discharge side of the pump (612), the pressure-operated switch in the pump starts the pump (604). Water is drawn from the non-potable water storage tank (606) by the pump (604) and supplied to the toilet tank (610) to refill it. The controller, utilizing the control algorithm, monitors and records frequency and timing of toilet tank flushing and refilling events and adapts to changing water use patterns in the residence (frequent or infrequent bath and showers, vacations) according to this pattern of use. If the use is infrequent and use of stored water is low or absent, the control algorithm monitoring storage and retention time, instructs the controller (602) to open the storage tank purge valve (616), pump the stored water from the tank (602) to sewer (618), and thus prevent the stored water from becoming septic. The algorithm, utilizing timing sequences, purges the storage tank in this manner on approximately 72 hour increments if it has not been previously emptied during that period by flushing activities. Should insufficient bath and shower water reach the non-potable water storage tank during regular daily operations, when a toilet is flushed and water no longer is available to the pump suction pipe, this causes the amperage draw on the motor to be reduced below the set-point managed by the control algorithm and the controller opens make-up water solenoid valve (620), introducing a timed pulse of potable make-up water (622) to the tank via an air gap (624). The operator is provided with audible tones (650) for alarms and operating status of the system.

The controller manages the timing and duration of make-up water cycles during pump station operations and ensures that the make-up water solenoid valve (620) is turned off when not required. The algorithm also provides for measurement of battery (630) voltage and battery management and maintenance through pulse-charging when needed via a power supply transformer (632) connected to mains (635) or optional solar power (634. When battery voltage drops or is discovered to be below set-point charging is initiated. When a desirable set-point voltage is reached, charging is shut off. When battery voltage is below a set-point and battery failure or charging problems are evident, the controller signals error by initiating an audible alarm sequence. Through monitoring sensors and timing sequences, the algorithm provides operator information and audible tone error massaging for malfunctions including failure of the make-up water supply to the grey water storage tank (602), excessive fill time for the toilet tank indicating leakage and failure in the plumbing, shutting down the pump (604) in such a situation preventing possible flooding, pump malfunction or failure, power supply failure and battery charging and battery status malfunctions.

Referring to Figure 7 there is illustrated another embodiment of the invention (700) which is an irrigation application, This embodiment utilizes stored rainwater (704) for the irrigation system (706). In this case a different control algorithm is programmed into the controller (702) from that described in Figure 6 for the domestic application. In the irrigation configuration, on initial start-up of the system only, the controller (702) , utilizing the control algorithm, calibrates the irrigation set-point at the 'just-like-that' soil moisture setting utilizing information received from the moisture sensor (710) which is set in compacted soil (712) adjusted to the moisture level desired by the system operator and retains that setting. The controller (702), in future irrigation cycles, utilizes this set-point to manage watering operations. Each day, just after dawn, as determined from day-night information received from a photocell (714), the controller, utilizing the algorithm, monitors the soil moisture information (716) received from the moisture sensor (710) and determines if the soil moisture level is above or below the 'just-like-that' set-point. If the moisture level is below set-point, the controller turns on the pump (720), and administers a timed pulse of water (722) from the storage tank (704) to the irrigation system (706), of approximately 5 minutes. After a 15 minute timed interval as determined by the controller (702), the controller tests the soil moisture level again and if necessary, administers a second 5 minute timed pulse of water. This procedure is repeated up to 5 times daily at which point, the 5 cycles having been repeated or the desired moisture level achieved during the process, the controller shuts off the pump and renders the irrigation system dormant for the day. If, on morning activation, the soil moisture level is above set-point, the controller does not initiate irrigation and goes dormant for the day. If the moisture sensor (710) has been pulled from the soil or is not functioning, the controller provides an audible error tone (750) and, utilizing the algorithm, at dawn administers two 5 minute pulses of watering and goes dormant for the day. It continues to do this until the function of the sensor is restored.

If there has been insufficient rain to replenish the storage tank and upon pump start-up the pump receives no water, the controller, senses a pump amperage drop, turns the pump off, and opens make up water valve (730). Make-up water (732) is supplied from the domestic potable water supply through air-gap (734) which prevents back-flow and contamination of the potable water supply. Each day, the controller records approximately how much water has been pumped for irrigation based on pump flow duration, and utilizing that information (736), administers only that amount of make-up water to the storage tank, to avoid displacing and thus wasting any potential for storing rainwater, or wasting potable make-up water to overflow.

Utilizing the algorithm, the controller (702) monitors battery voltage (740) and status of the battery (742). If the battery voltage is below a voltage set-point the controller pulses charges the battery, monitors voltage and stops charging when an upper set-point is achieved utilizing power supplied from the power supply (744) or optional solar panel (746).

The controller provides operator information in the form of audible tones (750) from a sound emitter facilitating the upwards and downwards moisture-setting adjustment from the original 'just-like-that' setting by using a series of timed commands which interrupt the daylight information received from the photocell (714). Alternately, in a different configuration of the controller board, 'up', 'down' and 'reset' buttons provide control adjustment. The initial 'just-like-that' calibration setting can be re-set for different soil conditions or if the pumping station is moved, by utilizing one of these commands which re-sets the overall calibration. In winter time, when the system is not required, withholding light from the photocell by covering the light port in the pumping station, renders the system dormant while still allowing the battery to be charged by the controller and power supply.

Industrial Applicability

Sequence List Text

Claims

A grey water management system comprising a modular pumping station comprising a digital controller, a water pump for pumping demand water through a demand water supply system to a plurality of grey water consuming devices wherein said water pump has a suction in communication with a volume of grey water stored in a grey water storage tank which collects and stores said volume grey water from a plurality of grey water drains and a pump outlet which is connected to a plurality of devices for consuming grey water, a normally closed first valve disposed between the grey water storage tank and a domestic water system for replenishing the contents of the grey water storage tank upon demand, a normally closed second valve disposed between the grey water storage tank and a sewer drain for draining the grey water storage tank to said sewer drain on demand, and a pressure switch logically connected to the water pump which activates the water pump upon a drop in water pressure in said demand water supply system.
The system of claim 1 further comprising a heat transfer device disposed within the grey water storage tank and submersed within the volume of grey water wherein the volume of grey water contains a quantity of residual heat energy derived from said plurality of grey water drains and wherein said heat transfer device transfers said quantity of residual heat energy from the volume of grey water to a hot water tank.
The system of claim 2 wherein the heat transfer device comprises a heat sink having a first side and a second side, and wherein said first side is fixed to a first heat exchange coil and said second side is fixed to a second heat exchange coil so that heat is transferred from said first heat exchange coil to said second exchange coil through said heat sink.
The system of claim 3 wherein the first heat exchange coil is in communication with a solar hot water heater and wherein the second heat exchanger is in communication with the hot water tank.
The system of claim 3 wherein the water pump comprises a 12VDC pump motor which is powered by one of a 120 VAC source through a transformer, a 12VDC battery and a 12VDC solar electrical panel.
The system of claim 1 wherein said digital controller comprises a memory device and a microprocessor having a software program having a control algorithm sensitive to a plurality of input signals comprising at least the following input signals: a water pump on signal, a water pump off signal, a demand water supply pressure signal, a water pump power draw signal, a 12VDC battery voltage signal and at least one operator input signal and wherein the control algorithm provides a plurality of output control signals comprising at least the following signals: a pump shutdown signal, a first and second valve open and close signal and a battery charge signal.
The system of claim 6 wherein the digital controller opens the normally closed second valve to initiate a sewer drain on a 72 hour cycle.
The system of claim 7 wherein the digital controller includes a grey water storage tank flush cycle following said sewer drain.
The system of claim 8 wherein said grey water storage tank flush cycle is initiated by the digital controller opening the normally closed first valve and permitting a predetermined amount of make-up water to enter and flush the grey water storage tank.
The system of claim 6 wherein the digital controller opens the normally closed first valve upon receipt of said water pump power draw signal exceeding a predetermined amperage which indicates that the pump suction is out of water and further wherein the digital controller records a time of first valve open.
The system of claim 6 wherein said pump shutdown signal is initiated when the water pump operates for a period of time longer than a predetermined period of time.
The system of claim 1 wherein said plurality of grey water drains comprise only shower and bath drains.
The system of claim 1 wherein said plurality of devices consuming grey water comprise only toilet flush tanks.
The system of claim 1 further comprising a water filtration device to filter the volume of grey water on a predetermined cycle.
The system of claim 1 further comprising a water purification device to purify the volume of grey water on said predetermined cycle.
A grey water management system comprising:
a modular pumping station comprising an enclosed housing for containing;

a digital controller comprising a microcontroller, a memory device connected to said microcontroller, an operator interface and a software program comprising a control algorithm;

a water pump for pumping a pulse of demand water through a demand water supply system to a plurality of grey water consuming devices;
wherein said water pump has:

a suction in communication with a volume of grey water stored in a grey water storage tank which collects and stores a volume grey water from a plurality of grey water drains; and,

a pump outlet which is connected to a plurality of devices for consuming said pulse of demand water;
a normally closed first valve disposed between said grey water storage tank and a domestic water supply system for replenishing the contents of the grey water storage tank upon demand by said digital controller;

a normally closed second valve disposed between the grey water storage tank and a sewer drain for draining the grey water storage tank to said sewer drain on demand by the digital controller;

a pressure switch logically connected to the water pump which activates the water pump upon a drop in water pressure in the demand water supply system;

a heat transfer device disposed within the grey water storage tank and submersed within the volume of grey water wherein the volume of grey water contains a quantity of residual heat energy derived from said plurality of grey water drains and wherein said heat transfer device transfers said quantity of residual heat energy from the volume of grey water to a hot water tank;

wherein the heat transfer device comprises a heat sink having a first side and a second side, and wherein said first side is fixed to a first heat exchange coil and said second side is fixed to a second heat exchange coil so that heat is transferred from said first heat exchange coil to said second exchange coil through said heat sink; and,

wherein the first heat exchange coil is in communication with a solar hot water heater and wherein the second heat exchanger is in communication with the hot water tank.
The system of claim 16 wherein said control algorithm is sensitive to a plurality of input signals comprising at least the following input signals: a water pump on signal, a water pump off signal, a demand water supply pressure signal, a water pump power draw signal, a 12VDC battery voltage signal and at least one operator input signal and wherein the control algorithm provides a plurality of control signals comprising at least the following signals: a pump shutdown signal, a first and second valve open and close signal and a battery charge signal.
The system of claim 17 wherein the control algorithm includes a learning cycle sensitive to a frequency and a time of toilet flushing, and the timing of the opening and the closing of the first and second valves and the timing of a plurality of grey water storage tank draining refilling events so that the control device can adjust to system water use patterns on an unsupervised basis.
A grey water management system comprising:

a grey water storage tank;

a modular pumping station comprising an enclosed housing for containing;

a digital controller comprising a microcontroller, a memory device connected to said microcontroller, an operator interface and a software program comprising a control algorithm;

a water pump for pumping a pulse of demand water from said grey water storage tank to an irrigation system;
wherein said water pump has:

a suction in communication with a volume of grey water stored in the grey water storage tank which collects and stores a volume grey water from a plurality of grey water drains; and,

a pump outlet which is connected to said irrigation system;
a normally closed first valve disposed between said grey water storage tank and a domestic water supply system for replenishing the contents of the grey water storage tank upon demand by said digital controller;

a soil moisture measuring circuit connected to the digital controller;

a daylight sensing circuit connected to the digital controller; and,

a rain water make-up system in communication with the grey water storage tank.