EP0295202B1 - Apparatus for introducing precise quantities of additives into a pressurised waterstream - Google Patents

Apparatus for introducing precise quantities of additives into a pressurised waterstream Download PDF

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Publication number
EP0295202B1
EP0295202B1 EP88810291A EP88810291A EP0295202B1 EP 0295202 B1 EP0295202 B1 EP 0295202B1 EP 88810291 A EP88810291 A EP 88810291A EP 88810291 A EP88810291 A EP 88810291A EP 0295202 B1 EP0295202 B1 EP 0295202B1
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EP
European Patent Office
Prior art keywords
additive
pipe
control valve
valve
pressure
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EP88810291A
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German (de)
French (fr)
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EP0295202A3 (en
EP0295202A2 (en
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Peter Dr. Hermann
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Tony Brandle AG
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Tony Brandle AG
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30—Injector mixers
    • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
    • B01F25/311—Injector mixers in conduits or tubes through which the main component flows for mixing more than two components; Devices specially adapted for generating foam
    • B01F25/3111—Devices specially adapted for generating foam, e.g. air foam
    • B01F25/31114—Devices specially adapted for generating foam, e.g. air foam with means for introducing an additional component, e.g. in predetermined proportion or in the main component

Definitions

  • the invention relates to a metering device for admixing additives to a pressurized water stream in a water pipe.
  • Dosing devices of this type are used above all in fire-fighting systems in which fire-fighting with extinguishing water alone is often not sufficient. In many cases, it is therefore necessary to mix the extinguishing water with a foam or another additive, for example.
  • the additive is added to the water flow by means of a pump which can be driven by a hydraulic motor.
  • the pump is controlled indirectly via a servo control valve, which reacts to pressure differences between the water pressure and the additive pressure. Dosing valves in the additive lines are provided before they enter the water line, but they are not controlled by the system.
  • the control of the dosing valve for additives should take place via the system. It is also advisable to pump the additive using a pump.
  • the known metering devices take too little account of the strong pressure fluctuations in the water flow and the associated effects on the regulation.
  • the control loop should also remain stable and react quickly to control deviations.
  • the pressure differential valve ensures that the pressure drop across the control valve remains largely constant even when the pressure in the additive line or in the water line changes.
  • the constant pressure difference has a positive effect on the control characteristics, so that there are no significant fluctuations in the desired mixing ratio.
  • the feed pump must have a greater delivery capacity when the control valve is fully open, so that the maximum amount of additive has to be delivered. If the control valve is only slightly open, it is not necessary for the feed pump or the drive device to be operated at the maximum output. An output corresponding to the actually required delivery quantity is sufficient, which saves energy and reduces noise.
  • Another advantage of adapting the delivery rate is that the additive does not heat up unnecessarily. The excess amount delivered has to be returned, which is associated with warming.
  • the controller forms the corresponding control signal from the amount of additive fed to the control valve and from the total amount of mixture in order to maintain the desired mixing ratio. Any fluctuations in the quantity of extinguishing water supplied to the metering device are also taken into account.
  • the control which is dependent on the required delivery rate, can be implemented particularly easily if the drive device is a gasoline engine with a speed controller assigned to the delivery pump and if the speed controller is connected to the control valve with a cable or with a linkage such that the speed increases with increasing valve opening .
  • the speed of the petrol engine can be regulated in a known manner via the throttle valve on the carburetor.
  • the position-dependent change in position on the control valve can be optimally transferred to the speed controller on the petrol engine using a cable or a linkage. With only a minimally opened control valve, the petrol engine therefore only runs at a minimal speed, which means that petrol consumption can be significantly reduced.
  • the drive device is a power take-off of a non-system main drive and if the speed of the power take-off can be controlled in stages or continuously with a gearbox that is controlled by the control valve.
  • the feed pump does not necessarily need its own drive unit. The feed pump is simply sufficient to connect to a power take-off.
  • the feed pump can be coupled to the power take-off via a gearbox, which changes the speed depending on the position of the control valve.
  • the above-mentioned return of excess conveyed additive can be further optimized in that a return line is connected to the additive line between the feed pump and the additive measuring device, which return line leads to the additive source and if an overpressure valve is arranged in the return line which, when a predetermined pressure is exceeded opens in the additive line and in this way returns the additive from the additive line to the additive source.
  • the recycling of excess additive to the additive source is also shown in the aforementioned US Pat. No. 4,324,294.
  • the return is not solved there in this simple way.
  • the amount of additive is even controlled by a control valve which is arranged in the return line. An attempt is made to maintain a constant mixing ratio by increasing or reducing the amount of additive returned. However, this is uneconomical because the feed pump must always be operated at full capacity.
  • a particularly versatile application of the metering device results when the additive source is an additive tank and when a directional valve is arranged in the additive line in front of the feed pump and can be switched from the additive tank to at least one additional additive line that leads to an external additive source. In this way, it is possible to switch over to another additive for a short time without switching off the system, which additive is also carried in a tank or which is extracted, for example, from a canister or barrel. Depending on the number of connections of the directional control valve, different additives could even be added alternately.
  • the water pipe 1 has two water connections 34, to which e.g. a hydrant or the outlet of a water pump can be connected.
  • An additive line 2 leads to the water line 1, where the additive is mixed into the water flow via a mixing device 28.
  • the mixing device can e.g. be a ring line which extends around the inner wall of the water line 1 and feeds the additive in a circular shape into the water flow.
  • the mixture is available in the desired mixing ratio at the two mixture connections 35.
  • a control valve 3 is arranged in the additive line 2.
  • This control valve is connected to an actuator 4, which receives 8 control pulses from a controller.
  • the desired mixing ratio can be set on an operating panel 9.
  • An additive measuring device 6 is installed in the additive line for determining the actual mixing ratio or for readjustment in the event of deviations from the desired state. This measures the amount of additive supplied to the control valve 3.
  • the total amount of mixture is in the water line 1 via a mixture measuring device 7 determined.
  • the signals from the two measuring devices 6 and 7 are each fed to a transducer 10 and 11, which emit signals proportional to the flow rate to the controller 8.
  • the structure and function of this controller are essentially already described in EP-A-230 860.
  • a pressure differential valve 5 is connected in the additive line 2 upstream of the control valve 3.
  • a control line 23 determines the pressure after the control valve 3, which can fluctuate depending on the water pressure in the water line.
  • This control pressure allows the pressure differential valve to keep a previously adjustable pressure drop of example 1 bar constant.
  • the water pressure at the water connections 34 can be set, for example, from 0 to 12 bar. This pressure is determined on a pressure gauge line 12 and can be read off on the control panel.
  • the additive is removed from an additive tank 16 and conveyed with a feed pump 17.
  • the feed pump 17, for example a diaphragm piston pump, is connected to a gasoline engine 18.
  • the petrol engine with an output of 11 hp, for example, is supplied with fuel from a fuel tank 22.
  • a starting device 21, which can be actuated from the control panel 9, is used to start the gasoline engine.
  • the gasoline engine 18 is provided with a speed controller 19 which controls the speed from, for example, 2000 to 4200 rpm. can regulate.
  • the speed controller is connected via a cable 20 to the control valve 3 or to its spindle. A displacement of the valve spindle therefore results in the speed controller being actuated.
  • the maximum speed of the gasoline engine 18 is reached with the control valve 3 fully open. Instead of the cable, a linkage would also be conceivable.
  • the speed controller 19 could also have other commands, for example electrical or optical signals, control commands from the control valve 3 or from it Get actuator 4.
  • a return line 24 is connected to the additive line 2.
  • This return line is provided with an overpressure valve 25, which can be set so that it responds to a desired overpressure.
  • the pressure in the additive line 2 can be read on the manometer 29. If a certain pressure of, for example, 15 bar is exceeded in the additive line, the pressure relief valve 25 opens and leads the unnecessary additive back into the additive tank 16.
  • the pressure relief valve 25 can be bridged with a handle, so that the entire pumped by the feed pump 17 for starting The amount of additive flows back to the additive tank 16. As soon as the feed pump 17 is operating normally and the desired operating pressure has been reached, the pressure relief valve 25 is switched to operation so that it only responds at the desired pressure.
  • a directional valve 26 is switched into the additive line 2, which can be switched from the feed tank 16 to at least one additional additive line 27.
  • an alternative additive can be pumped out of a drum 36 without interrupting operation by operating the directional valve 26.
  • the mixing ratio that can be programmed on the control panel 9 is, for example, zero to ten percent additive of the total flow rate determined with the mixture measuring device 7.
  • the amount of mixture can, for example, 180 to 2000 l / min. be.
  • the feed pump 17 can be provided with a pulsation damper 37 which detects the pressure compensates for bumps in the additive line 2.
  • the pressure differential valve 5 is generally set by the manufacturer and does not have to be adjusted later. When the delivery rate in the additive line 2 drops, the pressure difference can increase, for example, 1 bar at 100 l / min. to 2.5 bar at less than 10 l / min. With the normal delivery rates in the additive line 2, however, the pressure difference remains largely constant.
  • the feed pump 17 is driven by a power take-off 31 of a main drive 32 which is not related to the system.
  • This main drive can be, for example, the engine of a fire engine, which also drives hydraulic units, pumps, etc.
  • the delivery pump 17 is coupled to the power take-off 31 via a gear stage 30.
  • This gear stage 30 can change the speed of the power take-off 31 in a suitable manner such that the maximum speed is only reached when the control valve 3 is fully open.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
  • Control Of Non-Electrical Variables (AREA)
  • Accessories For Mixers (AREA)
  • Nozzles (AREA)
  • Cable Accessories (AREA)
  • Paper (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

The additive, for example extinguishing foam, is fed via an additive line (2) into the water line (1). A control valve (3) in the additive line (2), the actuator (4) of which receives actuating signals from a controller (8), serves to maintain the desired mixture ratio. To determine the actual value or to form the actuating signal, the additive is measured with an additive-measuring device (6) and the mixture is measured with a mixture-measuring device (7). In order to always obtain a constant pressure drop at the control valve (3) even during fluctuating water pressure in the water line, a pressure-difference valve (5) is fitted into the additive line (2). The drive device (18) for the feed pump (17) is provided with a speed regulator (19) whose rotational speed is controlled as a function of the position of the control valve (3). <IMAGE>

Description

Die Erfindung bezieht sich auf eine Dosiervorrichtung zum Beimischen von Additiven zu einem unter Druck stehenden Wasserstrom in einer Wasserleitung. Derartige Dosiervorrichtungen werden vor allem bei Brandbekämpfungssystemen eingesetzt, bei denen die Brandbekämpfung mit Löschwasser allein oft nicht genügt. In vielen Fällen ist es daher erforderlich, das Löschwasser beispielsweise mit einem Schaum oder mit einem anderen Additiv zu mischen.The invention relates to a metering device for admixing additives to a pressurized water stream in a water pipe. Dosing devices of this type are used above all in fire-fighting systems in which fire-fighting with extinguishing water alone is often not sufficient. In many cases, it is therefore necessary to mix the extinguishing water with a foam or another additive, for example.

Verschiedene Varianten zum Beimischen von Chemikalien zum Löschwasser sind beispielsweise bereits durch die US-A-4,324,294 bekannt geworden. Das Additiv kann dabei durch eine Pumpe oder durch an einem Venturirohr im Wasserstrom erzeugten Unterdruck gefördert werden. In allen Fällen sorgt ein Dosierventil dafür, dass die richtige Schaummenge der Wasser leitung zugeführt wird, wobei das Dosierventil entweder manuell oder durch ein reglergesteuertes Stellglied betätigbar ist.Various variants for adding chemicals to the extinguishing water have already become known, for example, from US-A-4,324,294. The additive can be conveyed by a pump or by negative pressure generated in a water flow on a Venturi tube. In all cases, a metering valve ensures that the correct amount of foam is fed to the water pipe, the metering valve being operable either manually or by a controller-controlled actuator.

Durch die US-A-3.047.003 ist eine gattungsmässig vergleichbare Vorrichtung bekannt geworden, bei der das Dosierventil für das Additiv von einem Druckdifferenz-Verstärker angesteuert wird, der auf Druckdifferenzen zwischen der Wasserleitung und der Additivleitung reagiert. Eine Förderpumpe für das Additiv ist nicht in das System intergriert.From US-A-3.047.003 a generic comparable device is known, in which the metering valve for the additive is controlled by a pressure difference amplifier, which reacts to pressure differences between the water line and the additive line. A feed pump for the additive is not integrated in the system.

Bei der Vorrichtung gemäss EP-A-98 055 erfolgt die Zumischung des Additivs zum Wasserstrom über eine Pumpe, die durch einen Hydraulikmotor antreibbar ist. Die Pumpe wird indirekt angesteuert über ein Servosteuerventil, das auf Druckdifferenzen zwischen dem Wasserdruck und dem Additivdruck reagiert. Dosierventile in den Additivleitungen sind zwar vor deren Eintritt in die Wasserleitung vorgesehen, sie sind aber nicht durch das System gesteuert.In the device according to EP-A-98 055, the additive is added to the water flow by means of a pump which can be driven by a hydraulic motor. The pump is controlled indirectly via a servo control valve, which reacts to pressure differences between the water pressure and the additive pressure. Dosing valves in the additive lines are provided before they enter the water line, but they are not controlled by the system.

Grundsätzlich sollte die Steuerung des Dosierventils für Additive über das System erfolgen. Auch eine Förderung des Additivs mittels einer Pumpe ist zweckmässig. Die bekannten Dosiervorrichtungen berücksichtigen jedoch die starken Druckschwankungen des Wasserstroms und die damit verbundenen Auswirkungen auf die Regelung zu wenig.In principle, the control of the dosing valve for additives should take place via the system. It is also advisable to pump the additive using a pump. However, the known metering devices take too little account of the strong pressure fluctuations in the water flow and the associated effects on the regulation.

Es ist daher eine Aufgabe der Erfindung, eine Dosiervorrichtung der eingangs genannten Art zu schaffen, bei der das Regelventil auch bei unterschiedlichen Druckverhältnissen in der Wasserleitung jeweils die optimale Additivmenge beimischt. Der Regelkreis soll ausserdem stabil bleiben und rasch auf Regelabweichungen reagieren. Diese Aufgabe wird erfindungsgemäss mit einer Dosiervorrichtung gelöst, welche die Merkmale im Anspruch 1 aufweist.It is therefore an object of the invention to provide a metering device of the type mentioned in the introduction, in which the control valve admixes the optimum amount of additive in each case even under different pressure conditions in the water line. The control loop should also remain stable and react quickly to control deviations. This object is achieved according to the invention with a metering device which has the features in claim 1.

Das Druckdifferenzventil sorgt dafür, dass der Druckabfall am Regelventil auch bei sich änderndem Druck in der Additivleitung oder in der Wasserleitung weitgehend konstant bleibt. Die gleichbleibende Druckdifferenz wirkt sich dabei positiv auf die Regelcharakteristik aus, so dass keine nennenswerten Schwankungen beim gewünschten Mischverhältnis auftreten. Ersichtlicherweise muss die Förderpumpe eine grössere Förderleistung erbringen, wenn das Regelventil vollständig geöffnet ist, so dass die maximale Additivmenge gefördert werden muss. Bei nur gering geöffnetem Regelventil ist es jedoch nicht erforderlich, dass die Förderpumpe bzw. die Antriebsvorrichtung mit der maximalen Leistung betrieben wird. Es genügt eine der tatsächlich erforderlichen Fördermenge entsprechende Leistung, womit Energie gespart und die Lärmentwicklung reduziert werden kann. Ein weiterer Vorteil der Anpassung der Förderleistung besteht darin, dass sich das Additiv nicht unnötig erwärmt. Die zuviel geförderte Menge muss nämlich wieder zurückgeführt werden, womit eine Erwärmung verbunden ist.The pressure differential valve ensures that the pressure drop across the control valve remains largely constant even when the pressure in the additive line or in the water line changes. The constant pressure difference has a positive effect on the control characteristics, so that there are no significant fluctuations in the desired mixing ratio. Obviously, the feed pump must have a greater delivery capacity when the control valve is fully open, so that the maximum amount of additive has to be delivered. If the control valve is only slightly open, it is not necessary for the feed pump or the drive device to be operated at the maximum output. An output corresponding to the actually required delivery quantity is sufficient, which saves energy and reduces noise. Another advantage of adapting the delivery rate is that the additive does not heat up unnecessarily. The excess amount delivered has to be returned, which is associated with warming.

Besonders vorteilhafte Resultate können erzielt werden, wenn die Additivmenge mit einer Additivmessvorrichtung vor dem Druckdifferenzventil messbar ist und wenn die Gemischmenge mit einer Gemischmessvorrichtung nach dem Eintritt der Additivleitung in die Wasserleitung messbar ist. Auf diese Weise bildet der Regler aus der zum Regelventil geführten Additivmenge und aus der gesamten Gemischmenge das entsprechende Regelsignal, um das gewünschte Mischverhältnis aufrecht zu erhalten. Dabei werden auch allfällige Schwankungen bei der der Dosiervorrichtung zugeführten Löschwassermenge berücksichtigt.Particularly advantageous results can be achieved if the amount of additive can be measured with an additive measuring device upstream of the pressure difference valve and if the amount of mixture can be measured with a mixture measuring device after the additive line has entered the water line. In this way, the controller forms the corresponding control signal from the amount of additive fed to the control valve and from the total amount of mixture in order to maintain the desired mixing ratio. Any fluctuations in the quantity of extinguishing water supplied to the metering device are also taken into account.

Die von der erforderlichen Förderleistung abhängige Steuerung lässt sich besonders einfach realisieren, wenn die Antriebsvorrichtung ein der Förderpumpe zugeordneter Benzinmotor mit einem Drehzahlregler ist und wenn der Drehzahlregler mit einem Seilzug oder mit einem Gestänge mit dem Regelventil derart verbunden ist, dass mit zunehmender Ventilöffnung die Drehzahl steigt. Die Drehzahl des Benzinmotors lässt sich auf bekannte Weise über die Drosselklappe am Vergaser regeln. Die stellungsabhängige Wegveränderung am Regelventil lässt sich durch einen Seilzug oder durch ein Gestänge optimal auf den Drehzahlregler am Benzinmotor übertragen. Bei nur minimal geöffnetem Regelventil macht der Benzinmotor daher nur minimale Drehzahl, wodurch der Benzinverbrauch erheblich gesenkt werden kann.The control, which is dependent on the required delivery rate, can be implemented particularly easily if the drive device is a gasoline engine with a speed controller assigned to the delivery pump and if the speed controller is connected to the control valve with a cable or with a linkage such that the speed increases with increasing valve opening . The speed of the petrol engine can be regulated in a known manner via the throttle valve on the carburetor. The position-dependent change in position on the control valve can be optimally transferred to the speed controller on the petrol engine using a cable or a linkage. With only a minimally opened control valve, the petrol engine therefore only runs at a minimal speed, which means that petrol consumption can be significantly reduced.

Einsparungen lassen sich aber auch auf optimale Weise erreichen, wenn die Antriebsvorrichtung ein Nebenabtrieb eines systemfremden Hauptantriebs ist und wenn die Drehzahl des Nebenabtriebes mit einem Getriebe stufenweise oder stufenlos steuerbar ist, das vom Regelventil gesteuert wird. Ist die Dosiervorrichtung beispielsweise auf einem Löschfahrzeug mit einer Antriebsvorrichtung für Hydrauliksysteme usw. angeordnet, so benötigt die Förderpumpe nicht unbedingt eine eigene Antriebseinheit. Es genügt dabei ohne weiteres, die Förderpumpe an einen Nebenabtrieb anzuschliessen. Die Förderpumpe kann dabei über ein Getriebe an den Nebenabtrieb gekuppelt werden, welches je nach der Stellung des Regelventils die Drehzahl verändert.However, savings can also be achieved in an optimal way if the drive device is a power take-off of a non-system main drive and if the speed of the power take-off can be controlled in stages or continuously with a gearbox that is controlled by the control valve. If the metering device is arranged, for example, on a fire truck with a drive device for hydraulic systems etc., the feed pump does not necessarily need its own drive unit. The feed pump is simply sufficient to connect to a power take-off. The feed pump can be coupled to the power take-off via a gearbox, which changes the speed depending on the position of the control valve.

Die bereits oben erwähnte Rückführung von zuviel gefördertem Additiv kann weiter dadurch optimiert werden, dass zwischen der Förderpumpe und der Additivmessvorrichtung eine Rückführleitung an die Additivleitung angeschlossen ist, welche zur Additivquelle zurückführt und wenn in der Rückführleitung ein Ueberdruckventil angeordnet ist, das beim Ueberschreiten eines vorbestimmbaren Druckes in der Additivleitung öffnet und derart Additiv aus der Additivleitung zur Additivquelle zurückführt. Die Rückführung von überschüssigem Additiv zur Additivquelle ist auch in der eingangs genannten US-A-4,324,294 dargestellt. Die Rückführung wird dort jedoch nicht auf diese einfache Weise gelöst. Teilweise erfolgt die Regelung der Additivmenge sogar durch ein Regelventil, welches in der Rückführleitung angeordnet ist. Durch Vergrösserung oder Verkleinerung der zurückgeführten Additivmenge wird versucht, ein konstantes Mischungsverhältnis aufrecht zu erhalten. Dies ist jedoch unwirtschaftlich, da die Förderpumpe immer mit voller Leistung betrieben werden muss.The above-mentioned return of excess conveyed additive can be further optimized in that a return line is connected to the additive line between the feed pump and the additive measuring device, which return line leads to the additive source and if an overpressure valve is arranged in the return line which, when a predetermined pressure is exceeded opens in the additive line and in this way returns the additive from the additive line to the additive source. The recycling of excess additive to the additive source is also shown in the aforementioned US Pat. No. 4,324,294. The return is not solved there in this simple way. In some cases, the amount of additive is even controlled by a control valve which is arranged in the return line. An attempt is made to maintain a constant mixing ratio by increasing or reducing the amount of additive returned. However, this is uneconomical because the feed pump must always be operated at full capacity.

Eine besonders vielseitige Anwendung der Dosiervorrichtung ergibt sich, wenn die Additivquelle ein Additivtank ist und wenn vor der Förderpumpe ein Wegeventil in der Additivleitung angeordnet ist, das vom Additivtank auf wenigstens eine zu sätzliche Additivleitung umschaltbar ist, die zu einer externen Additivquelle führt. Auf diese Weise ist es möglich, ohne Abschaltung des Systems kurzfristig auf ein anderes Additiv umzuschalten, das entweder ebenfalls in einem Tank mitgeführt wird oder das beispielsweise aus einem Kanister oder Fass abgesaugt wird. Je nach Anzahl der Anschlüsse des Wegeventils könnten sogar wahlweise verschiedene Additive wechselweise beigemischt werden.A particularly versatile application of the metering device results when the additive source is an additive tank and when a directional valve is arranged in the additive line in front of the feed pump and can be switched from the additive tank to at least one additional additive line that leads to an external additive source. In this way, it is possible to switch over to another additive for a short time without switching off the system, which additive is also carried in a tank or which is extracted, for example, from a canister or barrel. Depending on the number of connections of the directional control valve, different additives could even be added alternately.

Weitere Vorteile der Erfindung ergeben sich aus der nachfolgenden Beschreibung und aus den Zeichnungen. Verschiedene Ausführungsbeispiele der Erfindung sind in den Zeichnungen dargestellt und werden im folgenden genauer beschrieben. Es zeigen:

Figur 1
Die schematische Darstellung einer erfindungsgemässen Dosiervorrichtung mit einer durch einen Benzinmotor angetriebenen Förderpumpe, und
Figur 2
ein abgewandeltes Ausführungsbeispiel, bei dem die Förderpumpe durch einen Nebenabtrieb angetrieben wird.
Further advantages of the invention result from the following description and from the drawings. Various embodiments of the invention are illustrated in the drawings and are described in more detail below. Show it:
Figure 1
The schematic representation of a metering device according to the invention with a feed pump driven by a gasoline engine, and
Figure 2
a modified embodiment in which the feed pump is driven by a power take-off.

Wie in Figur 1 dargestellt hat die Wasserleitung 1 zwei Wasseranschlüsse 34, an welche z.B. ein Hydrant oder der Ausgang einer Wasserpumpe angeschlossen werden kann. Eine Additivleitung 2 führt zur Wasserleitung 1, wo das Additiv über eine Mischvorrichtung 28 in den Wasserstrom beigemischt wird. Die Mischvorrichtung kann z.B. eine Ringleitung sein, die sich um die Innenwand der Wasserleitung 1 erstreckt und das Additivkreisförmig in den Wasserstrom einspeist. Das Gemisch steht im gewünschten Mischungsverhältnis an den beiden Gemischanschlüssen 35 zur Verfügung.As shown in Figure 1, the water pipe 1 has two water connections 34, to which e.g. a hydrant or the outlet of a water pump can be connected. An additive line 2 leads to the water line 1, where the additive is mixed into the water flow via a mixing device 28. The mixing device can e.g. be a ring line which extends around the inner wall of the water line 1 and feeds the additive in a circular shape into the water flow. The mixture is available in the desired mixing ratio at the two mixture connections 35.

Um das gewünschte Mischungsverhältnis möglichst konstant zu halten, ist in der Additivleitung 2 ein Regelventil 3 angeordnet. Dieses Regelventil ist mit einem Stellglied 4 verbunden, welches von einem Regler 8 Steuerimpulse erhält. An einer Bedienungsplatte 9 ist dabei das gewünschte Mischungsverhältnis einstellbar. Für die Ermittlung des tatsächlichen Mischungsverhältnisses bzw. für die Nachregelung bei Abweichungen vom Sollzustand ist in die Additivleitung eine Additivmessvorrichtung 6 eingebaut. Diese misst die dem Regelventil 3 zugeführte Additivmenge. Die gesamte Gemischmenge wird über eine Gemischmessvorrichtung 7 in der Wasserleitung 1 ermittelt. Die Signale von den beiden Messvorrichtungen 6 und 7 werden je einem Messwertumformer 10 und 11 zugeführt, welche der Durchflussmenge proportionale Signale an den Regler 8 abgeben. Aufbau und Funktion dieses Reglers sind im wesentlichen bereits in der EP-A-230 860 beschrieben.In order to keep the desired mixing ratio as constant as possible, a control valve 3 is arranged in the additive line 2. This control valve is connected to an actuator 4, which receives 8 control pulses from a controller. The desired mixing ratio can be set on an operating panel 9. An additive measuring device 6 is installed in the additive line for determining the actual mixing ratio or for readjustment in the event of deviations from the desired state. This measures the amount of additive supplied to the control valve 3. The total amount of mixture is in the water line 1 via a mixture measuring device 7 determined. The signals from the two measuring devices 6 and 7 are each fed to a transducer 10 and 11, which emit signals proportional to the flow rate to the controller 8. The structure and function of this controller are essentially already described in EP-A-230 860.

Um den Druckabfall am Regelventil möglichst konstant zu halten, ist vor dem Regelventil 3 ein Druckdifferenzventil 5 in die Additivleitung 2 geschaltet. Eine Steuerleitung 23 ermittelt dabei den Druck nach dem Regelventil 3, der je nach Wasserdruck in der Wasserleitung schwanken kann. Dieser Steuerdruck erlaubt dem Druckdifferenzventil die Konstanthaltung eines vorher einstellbaren Druckabfalls von beispiels weise 1 bar. Der Wasserdruck an den Wasseranschlüssen 34 ist einstellbar von beispielsweise 0 bis 12 bar. Dieser Druck wird an einer Manometerleitung 12 ermittelt und kann an der Bedienungsplatte abgelesen werden.In order to keep the pressure drop across the control valve as constant as possible, a pressure differential valve 5 is connected in the additive line 2 upstream of the control valve 3. A control line 23 determines the pressure after the control valve 3, which can fluctuate depending on the water pressure in the water line. This control pressure allows the pressure differential valve to keep a previously adjustable pressure drop of example 1 bar constant. The water pressure at the water connections 34 can be set, for example, from 0 to 12 bar. This pressure is determined on a pressure gauge line 12 and can be read off on the control panel.

Das Additiv wird aus einem Additivtank 16 entnommen und mit einer Förderpumpe 17 gefördert. Die Förderpumpe 17, beispielsweise eine Membrankolbenpumpe, ist an einem Benzinmotor 18 angeschlossen. Der Benzinmotor mit einer Leistung von beispielsweise 11 PS wird aus einem Bezintank 22 mit Brennstoff versorgt. Für den Start des Benzinmotors dient eine Startvorrichtung 21, die von der Bedienungsplatte 9 aus betätigt werden kann. Der Benzinmotor 18 ist mit einem Drehzahlregler 19 versehen, der die Drehzahl von beispielsweise 2000 bis 4200 U/Min. regulieren kann. Der Drehzahlregler ist über einen Seilzug 20 mit dem Regelventil 3 bzw. mit dessen Spindel verbunden. Eine Verschiebung der Ventilspindel hat somit eine Betätigung des Drehzahlreglers zur Folge. Dabei wird bei ganz offenem Regelventil 3 die maximale Drehzahl des Benzinmotors 18 erreicht. Anstelle des Seilzuges wäre auch ein Gestänge denkbar. Selbstverständlich könnte der Drehzahlregler 19 auch auf anderem Wege, beispielsweise durch elektrische oder optische Signale Steuerbefehle vom Regelventil 3 bzw. von dessen Stellglied 4 erhalten.The additive is removed from an additive tank 16 and conveyed with a feed pump 17. The feed pump 17, for example a diaphragm piston pump, is connected to a gasoline engine 18. The petrol engine with an output of 11 hp, for example, is supplied with fuel from a fuel tank 22. A starting device 21, which can be actuated from the control panel 9, is used to start the gasoline engine. The gasoline engine 18 is provided with a speed controller 19 which controls the speed from, for example, 2000 to 4200 rpm. can regulate. The speed controller is connected via a cable 20 to the control valve 3 or to its spindle. A displacement of the valve spindle therefore results in the speed controller being actuated. The maximum speed of the gasoline engine 18 is reached with the control valve 3 fully open. Instead of the cable, a linkage would also be conceivable. Of course, the speed controller 19 could also have other commands, for example electrical or optical signals, control commands from the control valve 3 or from it Get actuator 4.

Unmittelbar nach der Förderpumpe 17 ist eine Rückführleitung 24 an die Additivleitung 2 angeschlossen. Diese Rückführleitung ist mit einem Ueberdruckventil 25 versehen, welches so eingestellt werden kann, dass es bei einem gewünschten Ueberdruck anspricht. Der in der Additivleitung 2 vorhandene Druck kann am Manometer 29 abgelesen werden. Wird in der Additivleitung ein bestimmter Druck von beispielsweise 15 bar überschritten, so öffnet das Ueberdruckventil 25 und führt nicht benötigtes Additiv zurück in den Additivtank 16. Das Ueberdruckventil 25 kann mit einem Handgriff überbrückt werden, so dass zum Anfahren die gesamte durch die Förderpumpe 17 geförderte Additivmenge wieder zurück zum Additivtank 16 strömt. Sobald die Förderpumpe 17 normal arbeitet und der gewünschte Betriebsdruck erreicht ist, wird das Ueberdruckventil 25 auf Betrieb geschaltet, so dass es nur noch beim gewünschten Ueberdruck anspricht.Immediately after the feed pump 17, a return line 24 is connected to the additive line 2. This return line is provided with an overpressure valve 25, which can be set so that it responds to a desired overpressure. The pressure in the additive line 2 can be read on the manometer 29. If a certain pressure of, for example, 15 bar is exceeded in the additive line, the pressure relief valve 25 opens and leads the unnecessary additive back into the additive tank 16. The pressure relief valve 25 can be bridged with a handle, so that the entire pumped by the feed pump 17 for starting The amount of additive flows back to the additive tank 16. As soon as the feed pump 17 is operating normally and the desired operating pressure has been reached, the pressure relief valve 25 is switched to operation so that it only responds at the desired pressure.

Vor der Förderpumpe 17 ist ein Wegeventil 26 in die Additivleitung 2 eingeschaltet, welches vom Fördertank 16 auf wenigstens eine zusätzliche Additivleitung 27 schaltbar ist. So kann ohne Betriebsunterbruch durch Betätigung des Wegeventils 26 beispielsweise ein alternatives Additiv aus einem Fass 36 abgepumpt werden.In front of the feed pump 17, a directional valve 26 is switched into the additive line 2, which can be switched from the feed tank 16 to at least one additional additive line 27. For example, an alternative additive can be pumped out of a drum 36 without interrupting operation by operating the directional valve 26.

Ersichtlicherweise werden Pumpenleistung, Rohrdurchmesser, Ventil- und Reglercharakteristik jeweils dem Einzelfall angepasst. Das Mischungsverhältnis, das an der Bedienungsplatte 9 programmiert werden kann, beträgt beispielsweise null bis zehn Prozent Additiv von der gesamten mit der Gemischmessvorrichtung 7 ermittelten Durchflussmenge. Die Gemischmenge kann beispielsweise 180 bis 2000 l/Min. betragen. Um ein durch die Charakteristik der Förderpumpe 17 bedingtes zu starkes Pulsieren der Additivmenge zu vermeiden, kann die Förderpumpe 17 mit einem Pulsationsdämpfer 37 versehen sein, der die Druck stösse in der Additivleitung 2 ausgleicht. Das Druckdifferenzventil 5 wird in der Regel vom Hersteller fest eingestellt und muss später nicht mehr verstellt werden. Bei sinkender Förderleistung in der Additivleitung 2 kann die Druckdifferenz ansteigen von beispielsweise 1 bar bei 100 l/Min. auf 2,5 bar bei weniger als 10 l/Min. Bei den normalerweise üblichen Fördermengen in der Additivleitung 2 bleibt die Druckdifferenz jedoch weitgehend konstant.It is evident that the pump output, pipe diameter, valve and controller characteristics are adapted to the individual case. The mixing ratio that can be programmed on the control panel 9 is, for example, zero to ten percent additive of the total flow rate determined with the mixture measuring device 7. The amount of mixture can, for example, 180 to 2000 l / min. be. In order to avoid excessive pulsation of the amount of additive due to the characteristics of the feed pump 17, the feed pump 17 can be provided with a pulsation damper 37 which detects the pressure compensates for bumps in the additive line 2. The pressure differential valve 5 is generally set by the manufacturer and does not have to be adjusted later. When the delivery rate in the additive line 2 drops, the pressure difference can increase, for example, 1 bar at 100 l / min. to 2.5 bar at less than 10 l / min. With the normal delivery rates in the additive line 2, however, the pressure difference remains largely constant.

Beim Ausführungsbeispiel gemäss Figur 2 ist die Anordnung mit Ausnahme des Antriebs für die Förderpumpe 17 gleich wie beim Ausführungsbeispiel gemäss Figur 1. Anstelle eines separaten Benzinmotors wird die Förderpumpe 17 jedoch von einem Nebenabtrieb 31 eines systemfremden Hauptantriebes 32 angetrieben. Dieser Hauptantrieb kann beispielsweise der Motor eines Löschfahrzeuges sein, der auch Hydraulikeinheiten, Pumpen usw. antreibt. Um die Förderleistung der Förderpumpe 17 ebenfalls in Abhängigkeit von der Position des Regelventils 3 steuern zu können, ist die Förderpumpe 17 über eine Getriebestufe 30 an den Nebenabtrieb 31 gekuppelt. Diese Getriebestufe 30 kann auf geeignete Weise die Drehzahl des Nebenabtriebes 31 derart verändern, dass nur bei voll geöffnetem Regelventil 3 die maximale Drehzahl erreicht wird. Diese Lösung wird vor allem dann realisiert werden, wenn die Dosiervorrichtung in ein Löschfahrzeug integriert wird und nicht als separates Aggregat ausgebildet ist.In the exemplary embodiment according to FIG. 2, the arrangement with the exception of the drive for the feed pump 17 is the same as in the exemplary embodiment according to FIG. 1. Instead of a separate gasoline engine, however, the feed pump 17 is driven by a power take-off 31 of a main drive 32 which is not related to the system. This main drive can be, for example, the engine of a fire engine, which also drives hydraulic units, pumps, etc. In order to also be able to control the delivery rate of the delivery pump 17 as a function of the position of the control valve 3, the delivery pump 17 is coupled to the power take-off 31 via a gear stage 30. This gear stage 30 can change the speed of the power take-off 31 in a suitable manner such that the maximum speed is only reached when the control valve 3 is fully open. This solution will be implemented above all if the metering device is integrated into a fire truck and is not designed as a separate unit.

Claims (7)

  1. Dosing device for mixing of additives into a pressurised water flow in a water pipe (1), in particular on a fire fighting system, with an additive pipe (2) leading to an additive source and leading to the water pipe (1) via a control valve (3) which is able to be controlled via a regulator controlled servo component (4) depending on the desired proportion of additive to water, and on which the pressure drop is able to be adjusted on a pressure differential valve (5) arranged in the additive pipe (2), a supply pump, which is connected with a drive device (18), being arranged in the additive pipe (2) and the drive device (18) being coordinated with the servo component (4) so that the drive device is able to be controlled depending on the position of the servo component, respectively the control valve (3).
  2. Dosing device according to claim 1, characterized in that the additive volume is able to be measured with an additive measuring device (6) upstream of the pressure differential valve (5) and the mixture volume is able to measured with a mixture measuring device (7) downstream of the additive pipe (2) inlet into the water pipe (1).
  3. Dosing device according to claim 1 or 2, characterized in that the drive device (18) is a petrol engine which is allocated to the supply pump (17) and which has a rotational speed control (19) and that the rotational speed control is connected to the servo component, respectively the control valve (3) by means of a Bowden cable (20) or a rod in such a way that the rotational speed increases with increasing valve opening.
  4. Dosing device according to claim 1 or 2, characterized in that the drive device is a power take-off (31) from a system remote main drive (32) and that the rotational speed of the power take-off is able to be controlled in steps or progressively with a transmission (30) which is controlled from the servo component, respectively the control valve (3).
  5. Dosing device according to claim 2, characterized in that a return pipe (24), which leads back to the additive source (16), is connected to the additive pipe (2) between the supply pump (17) and the additive measuring device (6), and that a pressure control valve (25), which opens when a predetermined pressure (13) in the additive pipe (2) is exceeded, is arranged in the return pipe (24), and in this way directs additive from the additive pipe (2) back to the additive source (16).
  6. Dosing device according to one of the claims 1 to 5, characterized in that the additive source is an additive tank (16) and that a directional valve (26), which is able to be switched over from the additive tank (16) to at least one additional additive pipe (27) leading to an external source, is arranged in the additive pipe (2) upstream of the supply pump (17).
  7. Dosing device according to claims 1 to 6, characterized in that the additive is able to be fed into the water flow via a mixing device (28) arranged in the water pipe (1).
EP88810291A 1987-06-10 1988-05-04 Apparatus for introducing precise quantities of additives into a pressurised waterstream Expired - Lifetime EP0295202B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88810291T ATE84234T1 (en) 1987-06-10 1988-05-04 DOSING DEVICE FOR MIXING ADDITIVES TO A PRESSURED WATER STREAM.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH2177/87 1987-06-10
CH2177/87A CH673091A5 (en) 1987-06-10 1987-06-10

Publications (3)

Publication Number Publication Date
EP0295202A2 EP0295202A2 (en) 1988-12-14
EP0295202A3 EP0295202A3 (en) 1989-11-23
EP0295202B1 true EP0295202B1 (en) 1993-01-07

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ID=4227692

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Application Number Title Priority Date Filing Date
EP88810291A Expired - Lifetime EP0295202B1 (en) 1987-06-10 1988-05-04 Apparatus for introducing precise quantities of additives into a pressurised waterstream

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EP (1) EP0295202B1 (en)
AT (1) ATE84234T1 (en)
CH (1) CH673091A5 (en)
DE (1) DE3877264D1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9818798D0 (en) * 1998-09-01 1998-10-21 Watkins Ivor Improvements relating to water treatment
AT501355B1 (en) * 2005-02-08 2006-12-15 Rosenbauer Int Ag FOAM EXTRACTION DEVICE AND METHOD OF OPERATION THEREOF
CH703784A1 (en) 2010-09-06 2012-03-15 Braendle Tony Ag Metering.
CN112138602A (en) * 2020-10-12 2020-12-29 李艳秋 Dust inhibitor adding device

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3047003A (en) * 1960-04-18 1962-07-31 Gamewell Co Flow proportioning system for foam producing apparatus
US4007755A (en) * 1974-01-18 1977-02-15 Sun Oil Company Of Pennsylvania Component injection system
FR2273315A1 (en) * 1975-01-17 1975-12-26 Sun Oil Co Pennsylvania Controlled injection of additive fluid into main fluid - e.g. addn of odoriser into liquefied fuel gases
US4324294A (en) * 1979-02-07 1982-04-13 John McLoughlin Chemical injection control system for fire fighting
US4420047A (en) * 1981-12-28 1983-12-13 Lockheed Corporation Stowable fire suppression system for aircraft cabins and the like
US4436487A (en) * 1982-06-29 1984-03-13 Enterra Corporation Foam liquid concentrate supply system
FR2586307B1 (en) * 1985-08-19 1988-09-16 Sfr Sa Robinetterie ASSEMBLY FOR TAKING IN AND CONTROLLING THE FLOW AND PRESSURE OF A LIQUID

Also Published As

Publication number Publication date
CH673091A5 (en) 1990-02-15
DE3877264D1 (en) 1993-02-18
EP0295202A3 (en) 1989-11-23
ATE84234T1 (en) 1993-01-15
EP0295202A2 (en) 1988-12-14

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