WO1995000717A1

WO1995000717A1 - Selective stormwater or sewer outlet control valve and control system

Info

Publication number: WO1995000717A1
Application number: PCT/AU1994/000362
Authority: WO
Inventors: Robert Garfield Millar
Original assignee: Robert Garfield Millar
Priority date: 1993-06-28
Filing date: 1994-06-28
Publication date: 1995-01-05

Abstract

A liquid/diversion system comprising: a collector having a liquid inlet, a first liquid outlet (26) and a second liquid outlet (22); valve means (30) movable between first and second operative positions, liquid exiting the collector via the first outlet (26) when the valve means (30) is in the first position and via the second outlet (22) when in the second position, said valve means (30) normally in said first position; a controller (110) for controlling the valve means; liquid level sensing means (120) for sensing the level of liquid in the collector and providing a level signal to the controller when the liquid is at a first level; said controller causing said valve means (30) to switch from the first to the second operative position for at least one preset time in response to a level signal from the level sensor (120).

Description

SELECTIVE STORM ATER OR SEWER OUTLET CONTROL VALVE AND CONTROL SYSTEM

TECHNICAL FIELD

This invention relates to separation and diversion of 'clean' and 'dirty' water run-off from a collecting surface, such as a roof or a washing station. More particularly it relates to a system of ensuring that substantialy all dirty run-off is diverted to a first storage/treatment system whilst clean run-off is diverted to a second storage/treatment.

Background Art

It is known to provide run-off surfaces used for washing vehicles with a collection pit having two waste water exits. A hydraulically operated valve selectively diverts water to a dirty water exit whilst a vehicle is being washed and for a preset period afterwards. At other times the valve closes the dirty water exit so as to cause water to flow into the clean water exit. Such a prior art system is shown in Fig 1.

The disadvantage of such a system is that water is only diverted to the dirty water exit as a consequence of a washing operation. When rain falls, all the run-off will flow to the clean water exit. However, if the collection surface is dirty, or as is frequently the case in large cities, the initial rainfall is polluted, this polluted water will find its way into the clean water system. Disclosure of the Invention

In one broad form the invention provides a liquid collection/diversion system comprising:

a collector having a liquid inlet, a first liquid outlet and a second liquid outlet;

valve means operable between first and second operative positions, in said first position liquid exiting the collector via the first outlet and via the second outlet when in the second position, said valve means normally in said first state;

a controller for controlling the valve means;

liquid level sensing means for sensing the level of liquid in the collector and providing a level signal to the controller when the liquid is at a first level;

said controller causing said valve means to switch from the first to the second operative position for at least one preset time in response to a level signal from the level sensor

The system may cycle a number of times. That is, the valve means will return to the first position and the water level will rise to the first level. The control means will then open the valve means to discharge the water. This may be repeated as many times as necessary. The controller may have a counter to count the number of discharges made and a way of resetting the counter. This may be a timer or a reset switch.

Preferably, the second outlet is above the first outlet and the first level so that no separate valve is required for it. Thus, when the valve remains in the first position water will 'overflow' out of the second outlet. Alternatively, the second outlet may be provided with its own valve so that it may be positioned anywhere.

Preferably, the first valve and, when installed, the second valve are hydraulically operated, preferably by water. However, other drive systems may be used.

The system may be used by itself, such as a diversion system for a roof-top rain collection system. Alternatively, it may be used in conjunction with a washing plant.

When used with a washing plant, preferably the system includes means to open the first valve when the washing plant is operating. It is desirable that the first valve stays open for a period after washing ceases. This may be by way of a hydraulic bled valve which slowly releases hydraulic pressure from the first valve allowing it to close. Alternatively, the controller may maintain pressure to the valve for the required time and then open a dump valve to release pressure when closing of the valve is required. The system may have the controller's counter reset by operation of the washing system.

The system may be a purely hydraulic system when used in conjunction with a washing plant. The controller may be a hydraulic pressure cylinder that discharges to the first valve when the liquid level reaches the required level. This system may be a single cycle or multiple cycle system, depending on the capacity of the hydraulic cylinder. Use of a float to trigger open a valve provides a simple way of activating the system. Furthermore it allows for multiple cycles, since the float will cut off pressure when the water level falls. Recharging of the cylinder occurs when washing applies a high pressure to the cylinder.

Brief Description of the Drawings

Fig 1. is a cross-sectional view of the prior art.

Fig 2. is a cross-sectional view showing the demand valve, delay valve and diverting valve of the prior art device of Fig 1.

Fig 3. is a partial cross-sectional view of the present invention.

Fig 4. is a schematic view of the control system of the embodiment shown in Fig 3.

Fig 5. is a circuit diagram of the control board of the control system of the embodiment shown in Fig 3. Fig 6. is an alternative embodiment of the invention.

Fig 7. is an alternate circuit diagram for the control of a diversion valve Description of Preferred Embodiments of the Invention

The preferred non-limiting embodiments of the invention utilise prior art components as shown in Figures 1 and 2. So as to understand the working of the invention, the prior art will be explained.

Referring to Figures 1 and 2, there is a cleaning system indicated generally by 10. The system 10 includes a mains water supply 12, a tap 14 and a hand-held hose 18 which is supplied with water when the tap 14 is opened. Water from the hose 16 falls on a collecting surface 18, from which it runs into a collection pit 20, together with any waste washed off the device being cleaned. It will be appreciated that the hose 16 may be replaced by any cleaning device or structure and that it may be the collection surface 18 itself that is being cleaned.

The collection pit 20 has a waste drain 22 in its base 24 and a clean water outlet 26 in a side wall 28. The clean water outlet is positioned above the base 24 so water will only flow into the clean water outlet 26 once the water level rises to its level. The waste drain 22 is provided with a diversion valve 30 which normally seals the waste drain unless activated. Thus rainwater falling on the collecting surface 18 will run into the collecting pit and fill it until the water discharges through the clean water outlet. However, when the diversion valve is open, all water will flow into the waste drain 22

The diversion valve 30 is hydraulically operated and the system includes a demand valve 32 positioned in the mains water supply 12, a delay valve 34 and a supply line 48 to the diversion valve 30.

The demand valve 32 has a central passage 40 in which is a port 42 communicating with the delay valve. A diaphragm 44 is provided downstream of the port and is spring-loaded by spring 46 in an upstream direction to normally seal across port 42 and hence close off port 42 to the mains water pressure. The diaphragm 44 is mounted on piston 46. When the tap is closed the piston seals the passageway but when it is open the mains pressure causes the piston and diaphragm to move down stream such that water may flow around the piston.

The mains water pressure is conveyed to the diversion valve 30 by supply line 48. The diversion valve 30 has a base 50 having an aperture 52 communicating with the waste water drain. The base includes a perforated cover 54 which extends upwards and over the aperture 52. A partially hollow shaft 56 depends downwardly from the cover 54 toward and into the aperture. Mounted on the shaft 56 is a valve element 58, slideable along the shaft

The valve element 58 includes a rubber diaphragm 60 that extends toward and is sealed to the shaft 56, thereby forming a sealed chamber 62. The valv e element 58 includes a lower section 64 which engages a spring 66 between itself and a flange 68 mounted on the shaft The spring 66 is in compression and so urges the valve element 58 downwards to seal the aperture 52. The chamber 62 communicates with a passageway 70 in the upper end of the shaft, which in turn communicates with the supply line 48. When hydraulic pressure is applied to the supply line 48, the chamber 52 increases in volume by raising the valve element 58 upwards against the spring 66. When hydraulic pressure is removed from the supply line the spring 66 urges the valve element 58 downwards. Downwards movement is only possible if the water in the supply line 48 and chamber 62 can escape. The delay valve 34 includes a small aperture 72 through which water may escape. Thus, the valve element 58 slowly descends as water is forced out of the aperture 72. The speed of closing is controlled by adjusting the effective size of aperture by needle 74.

Turning to Figures 3 and 4, there is shown a cleaning system 100 according to the invention. Similar parts are used as in the prior art and so are numbered as in Figures 1 and 2.

The basic operation of the demand valve 32, delay valve 34 and diversion valve 30 are as described with reference to Figures 1 and 2. However, it will be seen that upstream of the demand valve is an electro-mechanical control box 110. The control box includes a by-pass 112 line communicating with the mains water supply 12. The by-pass line 112 extends from the mains supply 12 to a T-intersection downstream of the delay valve 34, although it is not essential that this junction is downstream of the delay valve.

Intermediate the main supply 12 and the supply line 48, there is provided a valve 114, preferably a solenoid operated valve, for opening and closing communication between the main supply 12 and the supply line 48 via by-pass line 112.

Operation of the valve 114 is controlled by a controller 118 which receives inputs from a water level sensor 120, for sensing the level of water in the pit, a valve sensor 124 and a pressure sensor 122. The water level sensor 120 senses when the level of water in the pit is just below the clean water outlet and may be a float sensor, a conductivity sensor or a temperature sensor (since the run-off is almost always colder than ambient air temperature).

The pressure sensor 122 is located in either the supply line 48 or the by-pass line 112 downstream of the valve 114 and so senses when hydraulic pressure is supplied to the diversion valve 30. The valve sensor 124 senses the position of the valve element and provides an indication as to whether the diversion valve 30 is open or closed. It is linked to an alarm circuit which gives an alarm signal if the diversion valve 30 remains open or closed unexpectedly, such as if jammed open. This alarm circuit is shown in the circuit of Fig 7.

During washing operations, the operation of the system is as described with reference to Figures 1 and 2. Specifically, whilst water is drawn from the main supply line 12 for washing, the demand valve 32 supplies high pressure water to the diversion valve 30 and all water runs into the waste water drain. When washing ceases, water is released via delay valve 34 and the diversion valve 30 will close in due course. Application of the high pressure in the supply line trips the pressure sensor 124 and sends a signal to the controller. The controller will then be in a ready condition to act on an "activate" signal from the level sensor 120.

When water enters the pit its level eventually reaches that of the level sensor 120. The level sensor 120 signals the presence of water in the pit 20 to the controller 118 which in turn opens valve 114. High pressure is thus supplied to the supply line 48 from the main supply line 12 via by-pass line 112, thereby opening the diversion valve 30. The water level drops and the level sensor indicates this to the controller 118. Although the level has dropped, the valve 114 remains open for a predetermined time to allow the pit to fully drain. At the end of this time the valve 114 is closed, cutting off the supply line from the mains pressure. The diversion valve 30 then closes as water escapes from the delay valve.

The controller 118 may be adjusted so that it will open the diversion valve 30 more than once, for instance four times before the diversion valve stays closed and water exits the pit 20 via clean water exit. The counter in the controller is reset when the washing plant is next used. This is particularly useful when the surface 18 is large and the total amount of contaminated water to be disposed of is greater than the capacity of the pit 20. By cycling a set number of times, the amount of contaminated water diverted is known. In comparison, if a time delay alone is utilised, the quantity of water diverted is unknown. In light rain insufficient water may be divert whilst in heavy rain too much rain be diverted under a time delay system. However either system may be used.

Fig 5 shows a circuit diagram for the controller 118. The circuit includes a 4017 integrated circuit 130, which is used to set the number of cycles that the diversion valve 30 is opened and a 555 integrated circuit 132 which is used to set the time the solenoid valve 114 and hence diversion valve 30 remain open. The circuit has inputs for the water level sensor 120, which is normally open and a pressure switch 124 which is normally closed.

The operation of the circuit shall be described commencing with the circuit in its "ready" condition. In this condition the water level switch 120 is open, the counter 130 is at zero and the timer 132 is at rest. The water level rises to close water level switch 120 and so provide a high voltage to pin 1 of AND gate 134. Pin 2 of AND gate 134 is also high so pin 3 goes to a low voltage. This inputs to pin 5 on multivibrator 136 which switches output on pin 4 to a high voltage. The multivibrator includes a 47 micro-Farad capacitor 138 so that it maintains a high output at pin 4 for three or four seconds. Thus, when the water level sensor 120 is likely to open and close a number of times when the water level is at or near the required level, this will not effect the count of cycles. Pin 4 of multivibrator 136 feeds to pin 14 of counter 130 and pin 12 of AND gate 140. Pin 13 of gate 140 is also high so output pin 11 switches to low, which feeds into pin 2 of timer 132. The timer 132 outputs a high voltage at pin 3 and switches transistors 142 and 144 on, thereby supplying +12V across solenoid terminals 146. The timer 132 maintains a high voltage at pin 3 for a period of time determined by variable resistor 148 and capacitor 150. This is typically five to seven seconds.

Switching of transistor 142 on causes pin 2 of gate 134 to go low, thereby switching output on pin 3 high and output on pin 4 of multivibrator 136 low. When the timer 130 switches transistor 142 off, pin 2 goes high. However, by this time the level sensor 120 is open so output at pin 3 remains high. When the water level rises again to close level sensor 120, both pins 1 and 2 of gate 134 will be high, so will start the cycle again. It will be noted that with this arrangement, if water is flowing into the pit so fast that the level sensor 120 stays closed, the timer 132 will be triggered again immediately transistor 142 switches off and raises pin 2 of gate 134 to a high voltage. Each triggering will increment the counter 130 until the end of count is reached.

Pin 14 of counter 130 is an input for incrementing the counter. Thus, each time the level sensor closes and generates a high voltage at pin 14, the counter increments. The counter 132 has output pins 2, 4, 7, 10, 1, 5, 6, 9 and 11. These pins output a high voltage for a varying number of inputs to pin 14 after resetting. These are 1 through to 10, respectively, and are indicated next to the chip. When the respective number of inputs to pin 14 is reached the output goes low. In the diagram, pin 10, which gives a count of 4, is connected to both inputs of AND gate 152. This causes a high output at pin 11 of gate 152, which is fed to pin 13 of gate 140 when the count has not reached 4. When the count reaches 4, pin 10 goes low, causing a low output at pin 11 of gate 152 and at input pin 13 of gate 140. Since gate 140 requires both pins 12 and 13 to be high to switch output pin to a low voltage, gate 140 will not input a low voltage to timer 134, whether its input pin 12 is high or low, until the counter 130 is reset.

The output pin 11 of gate 152 is connected to two LEDS, 154 and 156. When pin 11 is high, yellow LED 154 lights, indicating the system is 'ready'. When pin 11 is high, red LED 156 lights, indicating the end of count and that the solenoid will not be activated until the counter is reset.

As mentioned above, the circuit has an input for a normally closed pressure switch. Pressure switch 122 inputs to pins 1 and 2 of and gate 158. When pressure switch 122 is closed, input pins 1 and 2 are at low voltage. Output pin 3 of gate 158 is high, as is pin 5 of multivibrator 160. Output pin 4 of multivibrator 160 is low, feeding into pin 15 of counter-chip 130. Pin 15 is the reset input of the counter and input of a high voltage to pin 15 resets the counter. When the pressure switch opens, pins 1 and 2 of gate 158 slowly rise to a high voltage and switch output pin 3 to a low voltage. This in turn causes output pin 4 of multivibrator 160 to switch to a high voltage, resetting the counter.

The input to pins 1 and 2 of gate 158 is via variable resistor 162, fixed resistors 164 and 165 and capacitor 166. When pressure switch opens it takes time for capacitor 166 to charge and rise the voltage of inputs 1 and 2. This time is set by resistors 162, 164 and 165 with variable resistor 162 providing an adjustment in this time. The purpose in the delay is that when the level sensor causes the solenoid valve 184 to be opened, the pressure in the supply line will open the pressure switch 124. This in turn would cause the counter to be reset every time the solenoid is activated. The time delay provided before pins 1 and 2 of gate 158 go high is of the order of fifteen seconds. Since the solenoid 114 and hence high pressure is applied for only five to ten seconds, the counter will not be reset. It will be noted that when the pressure switch closes, the arrangement means that capacitor 166 discharges rapidly to ground via resistor 165 alone.

In the above described circuit all of the logic gates are formed using 4093 integrated circuits. Provision of the AND gates providing high or low outputs for high inputs is by use of different pins for the inputs or the outputs. It will be appreciated that other integrated circuits may be utilised in this circuit or that other circuit arrangements having a similar functionality be used. In some circumstances, particularly when the diversion valve is opened more than once for rain, it is desirable that it close rapidly. Accordingly, the delay valve 34 needs to be set to release water via aperture 72 rapidly. This has the consequence of more water escaping the supply pipe when a high pressure is applied and also of closing the diversion valve rapidly at the end of washing operations, even though contaminated water will continue to collect some time after the water demand ceases and closes the demand valve 32. However, it will appreciated that this run-off from the collecting surface will be discharged once the water level reaches the sensor 120 as previously described.

To prevent waste of water the delay valve aperture 72 may be replaced with a simple solenoid valve. The valve would 'dump' the supply line to low pressure on provision of a suitable control from the controller 118. Obviously, the dump valve would be closed whilst the first valve 114 in the bypass line is open. During normal washing operation, the dump valve would be closed and would remain closed for a preset time before opening. This would avoid cycling of the diversion valve 30 - it could remain closed for sufficient time that substantially all the run-off will have passed into the waste water outlet before the dump valve opens and causes the diversion valve to close.

Fig 6 is a schematic view of a simple mechanical system for providing diversion of water. The diversion valve 30 is connected by supply line 48 to demand valve 32 and delay valve 34 as discussed with reference to Fig 1. However the supply line includes a first spur 80 which communicates via a one way valve 82 to a hydraulic cylinder 84. The one way valve 82 enables water to flow from the supply line 48 to the hydraulic cylinder 84 but not vice versa. A second spur 86 also communicates the supply hire 48 with the hydraulic cylinder 84 via a second valve 88. The second valve 88 is operated by a float 90 located in the pit 20. The valve 88 is closed when the water level is low and open when it is high. Thus when the water level reaches a preset height, the valve 88 opens, applying high pressure to the diversion valve 30 to open it. When the level falls, the float falls and closes valve 88. Depending on the capacity of the hydraulic cylinder 84, reopening of the diversion valve may occur more than once. When the cylinder is fully discharged the diversion valve will remain closed until the tap 14 is opened again. Hydraulic pressure will then be supplied to the supply line 48 and the cylinder 84 will be recharge via spur 80 and one way valve 82.

Fig 7 shows a variation of the basic controller circuitry. Similar components to the circuit of Fig 5 utilise the same numerals.

The water level triggering circuit is substantially as in Fig 5 but the timer clip 132 is not used to set the solenoid on time. Instead pin 11 of gate 150 feeds into a timing circuit 180. The timing circuit performs the same function as timer chip 132 of Fig 5 and feeds into the base of transistor 142.

The timer 132 acts as a retrigger timer to open the diversion valve 30 a set time after washing ceases. Timer 132 receives an input at pin 4 from multivibrator 160 and so starts timing when pressure switch opens at the end of washing. The timer 132 outputs to transistor 182 via pin 3 and turns transistor 182 on when washing ceases. Transistor 182 remains on for a time determined by resistor 148 and capacitor 150. The collector of transistor 182 inputs to the timing circuit 180 via capacitor 184. At the end of the time period the transistor is turned off causing the input to timer 180 to go high, thereby triggering the timing circuit 180 to open the solenoid valve 114 and diversion valve 30.

The circuit also includes a counter display 186. Counter 186 receives inputs from multivibrators 136 and 160. The input from multivibrator 160 causes the counter 186 to reset whilst the input from multivibrator 136 causes the display to increment by one.

The counter circuit is substantially as in Fig 5 but the output pins of counter 130 are connected to a DIP switch 187 to enable the required repeats to be easily selected.

The circuit also includes an alarm circuit to warn when the diversion valve 30 is jammed. The valve sensor 124 is normally closed and inputs to pins 1 and 2 of AND gate 188, causing pin 3 to be high and lighting "valve closed" LED 190. When the valve sensor 124 opens, pin 3 of gate 188 goes low causing "valve open" LED 192 to light. Pin 8 of "clock" 194 also goes low starting "clock" 194 counting which inputs to counter 196. After a certain number of cycles the counter provides a high voltage at its output pins which feed into transistors 198 and 200. Transistor 200 drives alarm LED 202 or piezo-eleσtric siren 204.

To prevent premature or false alarms, the counter 196 also receives an input at pin 10 from pin 3 of gate 158. When washing, pin 3 of gate 158 causes a high voltage to be applied to pin 10 of counter 196. This prevents counter 196 recognising input pulses from clock 194 and triggering an output. When washing ceases this high voltage at pin 10 is removed and clock 194 counts and increments counter 196 whilst the valve closes. If the valve does not close within the preset time, the alarm sounds. If the valve closes correctly and the sensor 124 opens, the clock 194 ceases and counter 196 is reset via gate 206 inputting to pin 11. Gate 206 receives inputs from the valve sensor 124 and gate 158 and resets counter when both the diversion valve 30 and pressure switch 122 are closed.

It will be appreciated that the invention includes applications merely for diverting the first fall of rain - there is no need for the invention to include a washing system. In such cases there is no need for a demand valve. It will also be appreciated that other forms of diversion valves may be utilised and that the diversion valve need not be activated from the mains water supply or even hydraulically or pneumatically. For instance, all the valves may be electrically operated if this is desired and sensors, such as flow sensors may determine when the washing plant is in use. In addition it will be appreciated that each outlet may be provided with its own valve that is opened and closed appropriately.

Industrial Applicability

The invention provides a system for selectively diverting clean and dirty water from a collection surface. Clean water can be stored or disposed of without treatment while dirty water can be treated by a suitable treatment plant that does not become overloaded with clean water.

Claims

THE CLAIMS

1. A liquid /diversion system comprising:

valve means movable between first and second operative positions, liquid exiting the collector via the first outlet when the valve means is in the first position and via the second outlet when in the second position, said valve means normally in said first position;

a controller for controlling the valve means;

liquid level sensing means for sensing the level of liquid in the collector and providing a level signal

to the controller when the liquid is at a first level;

said controller causing said valve means to switch from the first to the second operative position for at least one preset time in response to a level signal from the level sensor.

2. The system of claim 1 wherein, upon receipt of a preset number of subsequent level signals after receipt of the initial level signal, the controller switches the valve means to the second state for the preset time upon receipt of each subsequent level signal.

3. The system of claim 2 wherein the controller includes a counter for counting the number of level signals received and means to reset the counter.

4. The system of any one of claims 1 to 3 wherein the first outlet is above the second outlet and the first level.

5. The system of any one of claims 1 to 4 wherein the valve means comprises a hydraulically operated valve for blocking the second oulet.

6. The system of claim 5 wherein the controller includes a source of hydraulic pressure.

7. The system of any one of claims 1 to 6 wherein the first outlet is below at least the first level and there is a second valve for controlling passage of liquid from the collector to the first outlet.

8. The system of claim 7 wherein the second valve is controlled by the controller.

9. The system of claim 7 wherein only one of the second and first valves is open at any one time.

10. The system of any one of claims 1 to 9 including a washing plant discharging soiled liquid to the collector.

11. The system of claim 10 wherein the washing plant includes means to open the first valve whilst operating.

12. The system of claim 10 or claim 11 when dependent on claim 3 wherein operation of the washing plant resets the counter.

13. The system of any one of claims 10 to 13 wherein the controller maintains the first valve means in the second state a second preset time after washing ceases.

14. The system of any one of claims 10 to 13 when dependent on claim 5, wherein the source of hydraulic pressure is the washing fluid.

15. The system of any one of claims 1 to 14 wherein the control means includes a hydraulic pressure cylinder maintained or recharged to high pressure by a washing operation.

16. The system of any one of claims 1 to 15 wherein at least the first preset time is adjustable.

17. The system of claim 2 or any one of claims 3 to 16 when dependent on claim 2 wherein the preset number is adjustable.

18. A liquid collection /diversion system, substantially as herein described with reference to the drawings.