Abstract:
A self-contained device for sterilizing water is provided comprising a sterilizing product injection apparatus supplied with power by electric batteries so as to cause injection of the sterilizing product into a pipe transporting water to be treated, a water meter mounted in said pipe and having a head capable of generating a pulse each time the meter has recorded the flow of a predetermined amount of water, and an electric power regulator controlled by said pulses and which, whenever it receives a pulse, lets the current from the battery pass in the form of a short duration signal, the regulator interrupting the current from the battery between the pulses emitted by the meter.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a device for applying, independently and over a relatively long period of time, sterilization treatment at water points situated in isolated areas where it is impossible to use electric energy from the national grid. 
     Known sterilization devices of the chemical type have the drawback either of being unreliable or of requiring frequent maintenance. 
     It is true that it is possible to use conventional electric equipment which would be supplied by batteries, but the independence of such equipment would only be a few weeks, even a few days. Now, for such a system to be economic, it must be able to work independently for at least six months. 
     SUMMARY OF THE INVENTION 
     The present invention aims then at overcoming the above mentioned disadvantages of sterilization devices of the prior technique and provides a sterilization device of the type comprising, on the one hand, an apparatus for injecting a sterilizing product having electric control means which may be energized by electric batteries so as to cause injection of the sterilizing product into a pipe conveying water to be treated and, on the other hand, a water meter mounted on said pipe and having a head capable of generating an impulse whenever the meter has recorded the passage of a predetermined amount of water, said sterilization device further comprising an electric power regulator controlled by said pulses and which, whenever it receives a pulse, lets the current from the battery pass in the form of a short duration signal which actuates said control means so that a dose of sterilizing product is injected into the pipe, the regulator interrupting the current from the battery between the pulses emitted by the meter. 
     With the regulator therefore the current consumption of the control means of the injection apparatus is reduced to a minimum and any consumption between two pulses is suppressed. The self-contained working of the device of the invention is thus appreciably increased. 
     In a particular embodiment of the invention, the injection apparatus is formed by a conventional feed regulating pump and the sterilizing product used is soda hypochlorite. 
     In a variant, the injection apparatus is formed by a hydraulic control valve inserted in a service pipe bypassed to the water pipe to be treated and through which flows a small fraction of the delivery of the pipe, said valve being associated with an electromagnetic closure valve and with an electromagnetic opening valve controlled by the regulator, so that when a pulse is emitted, these valves are actuated so as to let a predetermined amount of service water pass through the valve, which water passes through a suction device, such as a hydro-ejector where it is mixed with a gaseous sterilizing product, for example chlorine, the chlorinated water thus obtained being introduced into the water pipe downstream of the connection point of the service pipe to the water intake pipe. 
     The control means comprise a first relay which acts on the opening electro-magnetic valve of the hydraulic control valve for a pedetermined time, a second relay which defines the opening time of the hydraulic valve, so the duration of injection of the sterilizing product, a third relay which acts, after said duration, on the electro-magnetic closure valve of the hydraulic valve and a device for resetting the system. 
     Because of the provision of the resetting device, if at the end of a cycle the electric contact remains closed, a new cycle cannot begin so that the power consumption of the system will be zero and a new dose of product is not dispensed. Similarly, if, following a failure of the electric contact a series of rapid pulses is emitted, a single cycle is executed. 
     Thus, the regulator of the invention uses the power of the batteries rationally since its consumption is zero between the cycles and is reduced to the strict minimum during the cycles. Thus the electric power supply circuit may be calculated so that the total power of the batteries may be spread out in cycles over a relatively long period of time, for example of the order of six months. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described in detail with reference to the accompanying drawings in which: 
     FIG. 1 is a block diagram of a water sterilization chain; 
     FIG. 2 is a diagram of the soda hypochlorite sterilization device using a feed regulator pump; 
     FIG. 3 is a diagram of the chlorine gas sterilization device comprising a hydraulic control valve; and 
     FIG. 4 is a simplified diagram of the operation of the sterilization device. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIG. 1, the sterilization device comprises electric batteries 10, equipped possibly with integrated solar collectors 12. These batteries supply with power the control means of a sterilizing product injection device which may be formed either by a feed regulator pump 14, or by a hydraulic control valve 16, or by any appropriate known apparatus. The sterilizing product dispensed by the feed regulator pump is preferably soda hypochlorite, whereas that used with the hydraulic control valve is chlorine gas. 
     In accordance with the basic notion of the invention between battery 10 and injection device 14 or 16 is interposed a power economizing regulator 18 driven by a water meter 20, with emitting head 21, mounted in the water pipe to be treated 24. The purpose of this meter, which may be likened to an electric switch, is to close a contact whenever a predetermined amount of water has flowed through the pipe, said contact causing the regulator to emit an electric pulse for triggering on the control cycle of the injection apparatus for a very short and adjustable period of time. 
     Thus, the regulator prevents any consumption of electricity during the interval between two treatment cycles and limits the consumption to a minimum value during injection sequences of the sterilizing product. 
     FIG. 2 shows one embodiment of the sterilization device using a feed regulator pump 14 capable of dispensing doses of soda hypochlorite which it takes from a reservoir 22. The water meter 20 is mounted in an inlet pipe 24 feeding the water to be treated. The regulation cabinet 18 also contains the batteries. When the emitting head 21 of the counter emits a pulse, the regulator sends the order to the pump to inject a dose of soda hypochlorite into pipe 24. This dose is injected through an injection tube 26 which is fixed to the pipe by a collar 28 and which opens thereinto downstream of meter 20. 
     FIG. 3 shows a sterilization device using a hydraulic control valve. This device comprises an intake pipe 30 which is divided into a main pipe 32 and a service pipe 36 which is connected to the hydraulic control valve 16 through a manual adjustment valve 37 for bypassing a service flow equal to a small fraction of the total delivery. This is measured by the emitting head meter 20 which is mounted in the intake pipe 30 upstream of the bypass. 
     The hydraulic control valve used may be of any known type, providing that it is compatible with the electromagnetic control valves. An example will be described hereafter of a valve which may be used with the device of the invention. Valve 16 comprises a body containing a pressure chamber not shown, in which is slidingly mounted a pilot valve member 40 and which may either by pressurized through a bypass 42 connected to the service pipe 36, the pilot valve member 40 then being urged during closure position of the hydraulic valve, or vented through pipe 43, the pilot valve member then being urged to its open position, which allows the service water to flow through the hydraulic valve. 
     In the bypass 42 are mounted an electromagnetic closure valve 44, a filter 45 and a manual adjustable cock 46 for diverting towards the bypass a propulsive flow equal to a small fraction of the service flow. In pipe 43 is mounted an electro-magnetic opening valve 48. Pipe 52 which leaves valve 16 passes through a hydro-ejector 54 to the input of which is connected pipe 56 from a depression chlorometer 58. 
     The main pipe 32 is equipped with a diagphragm or pressure stabilizer 33 for maintaining sufficient pressure in pipe 36 so that the hydro-ejector 54 operates correctly. 
     The electro-magnetic valves 44 and 48 are controlled by the regulator 18 which is itself driven by the impulses from the meter 20 with emitting head. At each pulse, a chlorination cycle is triggered off. This cycle comprises three periods. 
     First period: electro-magnetic opening valve 48 is energized for a variable time, between 0.5 and 1 second. The pressurized water which is imprisoned in the pressure chamber of the valve is then discharged to the atmosphere and the valve opens. The service water begins to pass through the hydro-ejector 54 where it is mixed with chlorine gas which is sucked in by the depression which reigns at the inlet of the hydro-ejector. 
     Second period: a time delay between 0 and 40 seconds for maintaining the valve in the open state; this time delay regulates then the chlorination time. The dose of chlorinated water thus formed is injected into pipes 32. 
     Third period: the electro-magnetic valve 44 is energized for a variable time, between 0.5 and 1 second. The pressure of the service pipe 36 is then communicated to the pilot valve member 40 of the hydraulic valve 16, which causes closure thereof and so stopping of the chlorination. 
     The device is then returned to its initial state and waits for a new pulse so as to begin a new cycle. 
     The operation of the device will now be described with reference to the simplified diagram of FIG. 4. The emitting head meter is shown schematically in this Figure by an electric contact 20 which may be either in the open position or in the closed position. The contact is normally in the open position and is closed whenever a predetermined amount of water has passed through the pipe transporting the water to be treated. 
     When contact 20 is open, the regulator does not consume any power and the treatment is stopped. 
     When the contact is closed, a current flows for a short time through the winding of a first relay, not shown, which triggers off the treatment cycle. This current is transformed in a shaping circuit 60 into a square wave signal, which acts on a starting up device 62. 
     If the injection apparatus is formed by a hydraulic control valve, two relays 64, 66 are actuated simultaneously, the first one acting on the electro-magnetic opening valve 48 of the hydraulic control valve (FIG. 3) for a time θ 1  which may be adjusted to about 0.5 second, the second one defining the time θ 2  for injection of the chlorinated water. After the time θ 2 , a third relay 68 is actuated so as to act on the electro-magnetic closure valve 44 of the hydraulic valve, for an adjustable time θ 2  of about 0.5 second, then a resetting device 70 is actuated. In this position, if at the end of a cycle contact 20 has remained closed a new cycle cannot begin. Similarly, if a series of rapid pulses is emitted by the contact, only one cycle will be executed. 
     If it is a question of a feed regulator pump, only relay 66 is actuated for an adjustable time θ 2  between 0.5 and 1 second, which time is required for injecting the sterilizing product, then the reset device 70 is actuated. 
     The power requirements of the sterilization device of the invention will be calculated in the particular case of the following numerical application: 
     
         ______________________________________voltage of the batteries  24 voltscurrent drawn by the regulator at                    200 mA24 voltscurrent drawn by the feed regulator                     1 Apump at 24 voltscurrent drawn by an electromagnetic                     85 mAvalve at 24 volts______________________________________ 
    
     From these data, the requirements are worked out as follows: 
     
         ______________________________________Power requirements for a feed regulator pump______________________________________Duration of a cycle    θ.sub.2 = 0.5 secondConsumption of the regulator                  100 mA.sConsumption of the feed regulator                  500 mA.spumpTOTAL                  600 mA.s______________________________________ 
    
     which is equivalent to 0.6/3600=0.166×10 -3  Ah at 24 volts. 
     
         ______________________________________Power requirements for a hydraulic valve______________________________________Duration of opening and closure              θ.sub.1 = θ.sub.3 = 0.5 sec.of the electromagnetic valvesDuration of injection of the              20 secondssterilizing productConsumption of the two electro-              2 × 0.5 × 85 = 85 mA.smagnetic valvesConsumption of the regulator              20 × 200 = 4 A.sTOTAL              4.085 A.s______________________________________ 
    
     which is equivalent to 4.085/3600=1.13×10 -3  A.h at 24 volts. 
     If 63 Ah batteries are used we will therefore theoretically obtain: 
     with a feed regulator pump ##EQU1##  possible cycles and with a hydraulic valve ##EQU2##  cycles for an injection time of 20 seconds. 
     If independent working is required for six months, this gives: 
     2100 cycles per day for the feed regulator pump and 
     300 cycles per day for the hydraulic control valve. 
     Similarly, theoretical curves can be plotted giving the independent working time of the device as a function of the desired number of cycles per day.