WO2021176477A1

WO2021176477A1 - Vehicle mounted system and method for distributed irritant spray

Info

Publication number: WO2021176477A1
Application number: PCT/IN2021/050212
Authority: WO
Inventors: Lalgopal Das; Palash KUMAR MAJI; Avik Chatterjee; Harish Hirani
Original assignee: Council Of Scientific And Industrial Research An Indian Registered Body Incorporated Under The Regn. Of Soc. Act (Act Xxi Of 1860)
Priority date: 2020-03-06
Filing date: 2021-03-04
Publication date: 2021-09-10
Also published as: GB2607501A; GB202211670D0; BR112022017561A2; ZA202209252B

Abstract

The vehicle mounted distributed irritant spray system has mechanisms for mist spraying near the vehicle and the jet spraying for moderate distance covering wide area around the vehicle. The mixing of the irritant liquid with the water is accomplished in the tank by whirling jets generated through bypassing the excess pumping fluid to whirl nozzle head. Proportioning of irritant solution with water for desired irritant concentration during spraying is carried out by operating valves in the bifurcated pump suction pipelines emerging from two different liquid storage tanks and valve in concentrated irritant pipeline from irritant vessel. The pumping system has diversion feature for utilization of the pressurized water for other application like foam generation for firefighting and washing the pipe network.

Description

VEHICLE MOUNTED SYSTEM AND METHOD FOR DISTRIBUTED

IRRITANT SPRAY

TITLE OF THE INVENTION:

The present invention relates to a vehicle mounted System and Method for distributed irritant spray. The System has mechanism for spraying proportioned irritant solution from all side of the vehicle covering close distance in the form of irritant liquid mist spray and moderate distance in the form of irritant liquid jet spray.

BACKGROUND OF THE INVENTIONS

Reference may be made to the US Patent No. 6,003,782A where in liquid spraying is carried out to the riotous mob from the overhead flying helicopter. The spraying system mainly consists of three sets of spray nozzles namely left bank, right bank and central bank mounted in single row on frontal undersurface of the helicopter. The spray system includes option of spraying water alone, mixture of water-tear gas solution or the mixture of tear gas solution and colored dye by operation of suitable pump and solenoid valves

The drawbacks of the system are [i] spraying only in the frontal side of the helicopter by six nozzles mounted in a row. A multiple number of to and fro movements are needed to control riotous mob; operator may face the difficulty to disperse the rioters in swift manner [ii] The helicopter mounted spraying system has the provision of spraying from undersurface of the helicopter; it may face difficulties of controlling the rioters present in the left and right side of the helicopter [iii] The helicopter may face difficulties in hovering over the narrow congested streets.

Reference may be made to the U.S. Patent No. 6679437 B2 wherein operator has to carry pressure vessels containing different pressurized gases, one with irritant gas, positioned in inverted condition with respect to each other and connected by tubing with a discharge regulating valve and discharge nozzle. By opening the discharge valve, the two gases are mixed in the common Tee and by operating trigger; the mixed fluid is released at high pressure through the nozzle.

The drawbacks of the system are [i] spraying only by a single nozzle and operator may face severe problem to control huge mass of riotous people [ii] The operator may get tired in carrying the two voluminous and high pressure cylinders [iii] Carrying the high pressure cylinder by a person is also an unsafe method.

Reference may be made to European Patent No. CN205957805 U wherein a high pressure pump sucks tear liquid from a tank and discharges through flexible hose and spray gun. High pressure tear liquid as emitted from the spray gun can be utilized for dispersing the riotous people. The spray gun is also equipped with high-voltage pulse generator for providing the electric shock to the two pins mounted at the right end of the spray gun for protecting the device from snatching and the operator from the riotous people

Drawbacks of the system are [i] operator may face difficulties in controlling a large mass of agitating mob by operating a single spray gun. [ii] The security of the operator may become vulnerable in facing the riotous people directly.

Reference may be made to the US Patent No 8453883 B2 wherein self defense spray device comprises of two units namely spray sub assembly and holder assembly. Spray sub assembly consists mainly of a pressurized canister containing irritant fluid, valve, and nozzle. A safety mechanism stops the nozzle from spraying irritant fluid in assembled condition of these two units namely sub assembly and holder assembly. At the time of spraying, these two units need to be disengaged. Thereafter, spraying of the irritant to the unruly person can be performed by pushing the nozzle of spraying device. Drawbacks of the system are [i] operator may face risk of dispersing a gang of unlawful and disruptive mob by the self defense spray system with a single spray gun. [ii] The operator is vulnerable to the agitating people directly.iii] the operator needs to carry the spray unit and to be well trained to operate the spray unit.

Reference may be made to European Patent No. CN204043485U where in irritant liquid is pumped to the atomizing transducer through necessary piping. High velocity air as discharged by turbojet engine mixes with irritant liquid in atomizing transducer and imparts high kinetic energy to the irritant liquid. The water mist as emitted from water cannon nozzles covers a long distance.

Drawbacks of the system are [i] it needs a high capacity turbojet engine for spraying [ii] the spraying system covers a long distance in single direction [front] only at time and therefore other side of the vehicle remains vulnerable to the riotous mob. Ii]the spray system occupies huge space of the vehicle and imposes a imitated space for the army personnel. Reference may be made to US Patent No. US5796330A where in a security system consist of storage tank, pump, a spray nozzle and interconnecting pipe and valves and bypass connection to the tank. The system is portable and bypass fluid is utilized for mixing.

Drawbacks of the system are [i] operator may face risk of dispersing a gang of unlawful and disruptive mob by with a single spray nozzle [ii] The operator is vulnerable to the agitating people directly lii] The mixing device like forced vortex generator utilizing the pressuring fluid in the storage tank could not be noticed in spray system The above prior art devices have certain shortcomings in spraying irritant liquid to agitating mob. In some devices spraying is only in single side by a row of spraying nozzles from helicopter in which operator may face difficulties to maneuver in narrow lanes of the city and also bear high cost. In other protecting sprayer, the person needs to carry pressurized gas cylinders and triggers the mixed irritant gas to the agitating persons. The operators may get exhausted in carrying the gas cylinders and may face difficulties in dispersing huge mass of rioters. Moreover, carrying high pressure gas cylinder is not a safe method. In other protecting devices using irritant fluid spraying to disperse rioting people is mostly operated by a single spray gun. It is very difficult to control huge mass of rioters only with a single spray gun. Moreover, operator is susceptible to agitating mob and may face the life danger. In other protecting sprayer huge turbojet engine is utilized for delivering high flow and pressurized air to carry mist irritant liquid to long distance incurring the high cost and bulky space requirement. More over the spray is single sided at times.

The present invented vehicle mounted distributed irritant spray system for riot control addresses the above shortcomings. The system can be safely utilized to disperse riotous and violent mob trying to ingress into the riot control vehicle or to expel the unruly mob in scattered manner from the disturbed site.

OBJECTIVES OF THE INVENTION:

1. The main object of the present invention is to provide vehicle mounted distributed liquid irritant spraying system for proportionate mixing of liquid irritant with water.

2. Yet another object of the present invention is to bypass the excess pumped liquid to the storage tank in such a manner to generate agitation by circumferential liquid jets for continuous mixing of liquid irritant with water [carrier liquid].

3. Still another object of the present invention is to spray the irritant liquid either from any combination of sides or all side of the vehicle by operating electrical switches from the driver's cabin. 4. Still another object of the invention is to provide additional branched pipe with valves from pump discharge pipeline to deliver clear water as needed for the generation of foam for firefighting of the vehicle.

5. Yet another object of the invention is to proportionately mix the liquid irritant with water even during the spraying operation.

6. Still another object of the invention is to wash the irritant-water piping with clear water and depressurizing the system to atmospheric pressure after washing.

7. Yet another object of the present invention is to make the system failsafe by providing manual overridden valves to all the solenoid valves.

BRIEF DESCRIPTION OF FIGURES :

The present invention is illustrated in figures 1 to 5 of the drawings accompanying this specification.

Figure 1 represents the perspective view of the spraying system.

Figure 2 plan view of the piping network mounted vehicle roof top Figure 3 represents the five-way junction distributor.

Figure 4 pipe distributor

Figure 5 perspective view of the dispenser for whirling jets

DETAILED DESCRIPTION OF THE INVENTION:

The present invention relates to a vehicle mounted System and Method for distributed irritant spray.The System comprises -

(a) Arrangement of Nozzles [28, 29, Fig. 1] means for mist spray or jet spray;

(b) Spray Fleaders [20, 21 , 22, 23 Fig. 2] means reducing the flow area from the distribution point; (c) Horizontal multiplex piston pump [12] mounted on the vehicle chassis means for driving from the engine power take off [PTO] and for sucking proportioned irritant solution and subsequently sending to multiport junctions [14] of the piping network mounted on the exterior of vehicle;

(d) Solenoid valves [24,25,26,27, Fig. 1] means for optionally spraying from any particular side or all sides of the vehicle as an alternative to manual globe valves [30, Fig. 1] means for failproof operation in the time of exigency;

(e) Proportioning valves means for combined operation of valves in the suction pipelines from two or more tanks and the valve in the concentrated irritant pipeline for proportionately mixing the irritant liquid with water to the desired irritant concentration;

(f) Whirling nozzle [49] head which takes the excess pressurized by-pass liquid and delivers to tank through at least four tangential nozzles [50], [51], [52] and [53] means for creating whirling jets that mix the irritant solution with water without any aid of additional power

A positive displacement type triplex pump, powered from vehicle engine Power Take-Off [PTO] via suitable belt-pulley drive arrangement, sucks the irritant liquid from the inboard tank through the suction pipe line.

The pump delivers the high pressure liquid to the discharge pipe and the excess liquid is bypassed to the tank to safeguard the pump from overpressure.

The concentrated irritant solution is dosed to water in the tank from irritant bottle by operating a valve at the outlet.

The bypassed liquid from the pump is delivered in the form of whirling jets in the tank for mixing the liquid irritant with the water. The pump discharge pipe meets to a common n-way junction distributor. Four distributing pipes with inline solenoid operated valves [Off/On] are emerged from the n-way junction distributor. Thus [n-1] pipes are connected to the left side, right side, front and back side pipe headers. All the pipe headers can be supplied with pressurized proportioned irritant liquid simultaneously or any pipe header as per need by operating respective solenoid operated valves. The solenoid valves are overridden by a single manual valve which supplies the proportioned irritant liquid to all the pipe headers to make the system failsafe in case of non operation of the solenoid valves. A number of nozzles are fitted to the pipe header all-round the vehicle for spraying the proportioned irritant liquid. Some nozzles are for spraying in the form of jets to cover a moderate distance from the vehicle and rest are for mist formation near the vehicle. Thus the spraying system covers a wide area around the vehicle with the two distinct spraying arrangements. Two separate liquids can be stored in the internally bifurcated two tanks. Two suction pipelines with valves emerging from the tanks are converged to a single suction pipeline to the pump. Thus proportioning of liquid can also be done by operating valves in the suction pipelines and valve in the concentrated irritant solution pipeline. Additional branched pipe with valves from the pump discharge pipeline is also provided and same can also be utilized to deliver clear water for generation of foam for firefighting of the vehicle. Spraying of irritant solution covers wide area all around the riot control vehicle. The irritant spraying is with the option of spraying from any side or all side of the vehicle. Mixing of the required irritant liquid with water is achieved utilizing excess pumped liquid without any additional consumption of power. Proportioning of irritant liquid and water to the desired irritant concentration is carried out even during spraying. Provision for delivery of pressurized clear water for foam generation for fire-fighting of the vehicle and washing the pipe network with clear water utilizing the same pumping system are also integrated. The System is designed such that the concentration of irritant in the sprayed liquid can be varied in real time by operating valves mounted in the bifurcated suction pipe lines of the pump so as to proportion the liquid irritant with water to the desired irritant concentration

The invention has a special arrangement for covering wide irritant spray area around the vehicle which is accomplished by spraying irritant liquid from a combination of nozzles. The irritant spray from mist spray nozzles and jet spray nozzles cover short distance and moderate distance respectively around the vehicle.

The invention has the option for spraying from any side or all side of the vehicle is operated by operating the solenoid valves of spray headers by electrical switches from driver’s cabin depending on the riot situation. Users need to do this operation to control riot situation on the ground and to resist ingress of agitated mobs.

The invention has the arrangement of mixing of the required irritant liquid with water is devised by incorporation of whirling liquid jets in the tank utilizing excess bypassed liquid from the pump without any additional power requirement as it is done in other cases through a separate motorized stirrer.

A Method for distributing irritant spray has been devised comprising the steps of - a. irritant water solution and clear water are kept segregated in different storage tanks; b. suction pipes from at least two kinds of storage tanks are merged to a single suction pipe and is connected to the multiplex piston pump. c. each tank is connected with respective suction pipes with solenoid valve and manual globe valves in parallel combination; d. concentrated irritant liquid is supplied in a controlled manner; e. the excess pressurized by-pass liquid is delivered to tank for creating whirling jets that mix the irritant solution with water without any aid of additional power wherein the concentration of irritant in the sprayed liquid can be varied in real time by operating valves mounted in the bifurcated suction pipe lines of the pump so as to proportion the liquid irritant with water to the desired irritant concentration

In this Method, the irritant solution is proportionately dosed to water to the desired irritant concentration by combined operation of valves in the suction pipelines from both tanks and the valve in the concentrated irritant pipeline. A pipe with valves is branched from the pump discharge pipe to deliver clear water for the generation of foam for firefighting of the vehicle. The irritant-water solution system is kept isolated by operating the valves during this operation.

The following are the steps to be accomplished to spray proportioned irritant liquid from the vehicle mounted spray system.

First step: - To fill tank [1] and tank [2] with clear water and small irritant bottle [10] with liquid irritant. The required quantity of liquid irritant is added to tank [1] by opening the manual globe valve [11] and observing the graduated scale fixed to the bottle [10].

Second step: - The tank [2] is kept isolated from the spray system by closing solenoid valve [9] and manual globe valve [8] in suction pipeline and solenoid valve [18] with manual override valve [19] in the bypass pipeline.

Third step: - To start pump by connecting with engine through the engine power takeoff [PTO] keeping the discharge solenoid operated valves [24], [25], [26], [27]and [36] normally closed type and manual discharge valve [30], [37] in shut-off condition and bypass solenoid operated valve [16] with manual override valve [17] in full open condition so that full liquid is bypassed to tank [1] in whirling jet manner for proper mixing of liquid irritant with water. The proportioned irritant water solution is ready in tank 11

Fourth step: - The solenoid operated valves [24], [25], [26] and [27] should be switched on from drivers cabin to open condition and pump flow control valve [15] should operated to send maximum liquid to the spray headers and the rest liquid is bypassed to Tank[1]

Fifth Step: - The spraying of proportioned irritant water solution should be started all-round the vehicle from atomizing nozzles [28] and jet nozzles [29].

Sixth Step:- The manual globe valve [9] in the suction pipeline from tank [2] and the manual globe valve [11] in the irritant pipeline from vessel[10] may be controlled for proper proportioning of liquid irritant with water. Seventh Step:- The valve [8] or [9] should kept opened for supplying clear water to pump and to the pipe network after completion of irritant liquid spraying. The valve [7] and [6] should be closed for stopping the supply of water irritant solution to the pipe network. The excess water from the pump should be by-passed to tank [1] by opening the valves [16] or [17]. The system should be depressurized to atmospheric pressure by opening the valve [36] or [37] in the branched piping after washing the irritant pipe network with clear water.

The irritant water piping system can be washed after irritant water spraying with clear water by pumping the clear water from the second tank through the pipe network and it can also be depressurized by discharging the pressurized water through branched pipe line meant for generation of foam. The piping system remains irritant liquid free in normal time and safe for the security persons. The features of the Vehicle Mounted System and method for Distributed Irritant Spray for the Riot Control application are described below- Figure 1 illustrates the perspective view of the spraying system which includes a liquid storage tanks [1] and [2] and in which desired liquid is stored. Pump suction [3] and bypass return pipeline [4] are connected to the respective tanks. Pump discharge port is [5]. The suction pipeline [3] to tank [1] is controlled by operating solenoid valve [6] and manual globe valve [7] in parallel combination. The suction pipeline [3] is also connected to the tank [2] via solenoid valve [8] and manual globe valve [9] in parallel combination. Tank [1] is mainly for storing water- irritant solution and tank [2] is mainly for storing water. A small concentrated irritant bottle [10] with transparent graduation level mark and filling cap is connected to tank [1] through a manual globe valve [11]. By operating two sets of valves in the pump suction pipelines and the valve [11] in concentrated irritant pipeline, proportioning of liquid irritant and water solution can be done. The horizontal triplex piston pump [12] mounted on the vehicle chassis and driven from the engine power take off [PTO]. The pump [12] sucks proportioned irritant solution through suction pipeline [3] and delivers pressurized irritant liquid to the discharge pipe [13] and subsequently to five way junctions [14] of the piping network mounted on the vehicle rooftop. Liquid supply to the piping network is controlled by operating pump flow control valve [15]. The excess liquid is by-passed to storage tank [1] by activating the solenoid operated valve [16] with manual override valve [17] The excess clear water can also be by-passed to tank [2] by operating solenoid valve [18] with manual override valve [19]. Pressurized and proportioned irritant liquid is distributed to four distributing headers namely left side header [20], right side header [21], front side header [22] and back side header [23] by activating solenoid operated valves [24], [25], [26] and [27] respectively. All the distributing headers can be supplied proportioned irritant liquid simultaneously or individually as desired by the operator by activating the electrical switches in the driver’s cabin. A series of nozzles attached to the distributor headers [20], [21], [22]&[23] and proportioned irritant liquid is sprayed outward from the vehicle. The two types of nozzles are selected namely atomizing nozzle [28] for short distance spraying of about 1.5 m and wide spray angle and jet nozzle [29] for moderate spray distance of about 10 m. Additionally, a pipe connection from the discharge pipeline [13] with a globe valve [30] is provided to the all the distributor headers [20], [21], [22] and [23] through respective non-return valves [31], [32], [33] and [34] to the irritant spraying system to make the system failsafe in case of non-operation of any solenoid valve. A pipe outlet [35] with solenoid valve [36] with manual overridden globe valve [37] is branched from the pump discharge pipeline for some other purpose like foam generation for firefighting of the vehicle. Figure 2 represents plan view of the piping network mounted vehicle roof top which includes five-way junction distributor [14] which is connected to four distributing headers [20], [21], [22] & [23] through solenoid operated valves [24], [25], [26] and [27] respectively. The two types of nozzles are selected namely atomizing nozzle [28] for short distance spraying and wide spray angle and jet nozzle [29] for long spray distance. The nozzles are connected to the distributor header. A separate pipe connection with globe valve [30] from pump discharge pipeline [13] to four distributing headers [20], [21], [22]&[23] through the non-return valves [31], [32], [33] and [34] has been provided to make the system failsafe.

Figure 3 represents five-way junction distributor which includes one incoming threaded port [38] for connecting the pump discharge pipe [13] and four threaded outlet ports [39], [40], [41] and [42] for connection to four distributor header through suitable piping. The five-way junction distributor includes cylindrical body [43] and two ellipsoidal cover heads [44] & [45] welded with cylindrical body.

Figure 4 represents half of the pipe distributor header [20] which includes the pipes [46], [47] and [48] of varying flow cross sectional flow area depending on required cumulative flow of the nozzles need to be supplied. Figure 5 represents plan view of the whirling nozzle [49] head which takes the excess pressurized by-pass liquid and delivers to tank through four tangential nozzles [50], [51], [52] and [53]. The pressurized liquid emerged in tank as submerged jets in the tangential direction of a circle which aids in creation of forced vortex. These whirling jets mix the irritant solution with the water without any aid of additional power in contrast to conventional stirrer.

Accordingly the present invention provides vehicle mounted System and Method for distributed irritant spray comprising pump suction pipeline[3] bifurcated to connect to two liquid storage tanks[1] and [2], arrangement of solenoid valves[6],[8] and manual globe valves[7],[9] in the suction pipeline[3] for switching over from one pumping liquid to another and proportionately mixing of liquid irritant and water by operation of valves in the bifurcated suction pipeline[3] and concentrated irritant pipeline, five way junction[14] at pump discharge pipelined 3], direction change of pressurized liquid as per application, tangential whirling nozzle head[49] in the liquid storage tank[1] for mixing the liquid irritant with water by jet agitation, utilizing bypassed liquid of the pump, coverage of wide spray area around the vehicle by mist as well as jet spray.

In an embodiment of the present invention is tangential whirl nozzle head [49] for mixing of irritant liquid with water in the tank [1]

In yet another embodiment of the present invention is diversion of the bifurcated suction pipeline between two tanks as per need of the liquid by operating solenoid valves [6,8] or manual valves [7,9].

In still another embodiment of the present invention is five-way pipe distributor to the four sided spray headers [20], [21], [22]&[23].

In yet another embodiment of the present invention is irritant spraying by means of atomizing nozzles [28] and jet nozzles [29].

The use of the present System is to be done in a manner such that - a. Spraying of irritant solution is for wide coverage area all around riot control vehicle. b. The irritant spraying is with the option of spraying in any side or all side of the vehicle. c. Mixing of the required irritant liquid with water through excess pumped liquid in the form of submerged whirling jets without any additional consumption of power d. Proportionately dosing of irritant liquid and water to the desired irritant concentration even during spraying e. Integrated delivery of pressurized clear water for foam generation for fire-fighting of the vehicle and other purposes utilizing the same pumping system.

ADVANTAGES OF THE INVENTION:

The main advantages of the present invention are:

1. The provision for spraying in the form of mist for short distance and also in the form of jets, thus covering wide spray area around the vehicle.

2. Utilization of excess bypass liquid in the form of whirling jets in the tank for mixing of the irritant liquid with water without consuming additional power.

3. The provision for utilization of the same pumping system to deliver clear water by operation of suitable solenoid valves with manual overridden in pump suction and discharge pipeline.

4. Proportioning of irritant liquid with water to the desired concentration by operating valves in the bifurcated suction pipeline from the pump and concentrated irritant dosing pipeline to the tank.

5. The spraying in any side or all sides of the vehicle can be accomplished by the solenoid valves from the electrical switches in the driver’s cabin. The spraying system is failsafe with incorporation of manual override operating provision along with operation by control of electrical switches. The clear water in second tank can be used for washing the irritant liquid pipe line after completion of the work.

Claims

We claim:

1. A vehicle mounted system and method for distributed irritant spray comprising-

(a) Arrangement of Nozzles [28, 29, Fig. 1] means for mist spray or jet spray;

(b) Spray Headers [20, 21 , 22, 23 Fig. 2] means reducing the flow area from the distribution point;

(c) Horizontal multiplex piston pump [12] mounted on the vehicle chassis means for driving from the engine power take off [PTO] and for sucking proportioned irritant solution and subsequently sending to multiport junctions [14] of the piping network mounted on the exterior of vehicle;

2. The vehicle mounted system as claimed in Claim 1 wherein the pressurized liquid emerged in tank for mixing of liquid irritant with water in the form of submerged jets in tangential direction of a circle for creation of forced vortex.

3. The vehicle mounted system as claimed in Claim 1 wherein the concentration of irritant in the sprayed liquid is proportioned in real time by operating valves mounted in the bifurcated suction pipe lines of the pump.

4. The vehicle mounted system as claimed in Claim 1 wherein valves mounted on the suction pipes emerging from at least two tanks along with delivery valves on the concentrated irritant pipe enables the concentration of irritant in the sprayed liquid to be varied even during spraying condition.

5. The vehicle mounted system as claimed in Claim 1 wherein a branched pipe with valves from same or separate branched pipe with valves emanate from pump discharge pipe for application of clear water in generation of foam.

6. The vehicle mounted system as claimed in Claim 1 wherein the irritant pipe network is optionally connected to clear water tank and is depressurized to atmospheric pressure by discharging clear water through the branched piping system.

7. A Method for distributing irritant spray comprising the steps of - a. irritant water solution and clear water are kept segregated in different storage tanks; b. suction pipes from at least two kinds of storage tanks are merged to a single suction pipe and is connected to the multiplex piston pump. c. each tank is connected with respective suction pipes with solenoid valve and manual globe valves in parallel combination; d. concentrated irritant liquid is supplied in a controlled manner; e. the excess pressurized by-pass liquid is delivered to tank for creating whirling jets that mix the irritant solution with water without any aid of additional power wherein the concentration of irritant in the sprayed liquid can be varied in real time by operating valves mounted in the bifurcated suction pipe lines of the pump so as to proportion the liquid irritant with water to the desired irritant concentration

8. The Method for distributing irritant spray as claimed in Claim 7 wherein the excess pumped liquid is bypassed to the irritant-water solution tank for mixing of irritant with water.

9. The Method for distributing irritant spray as claimed in Claim 7 wherein the pump outlet is connected to n- way junctions having [n- 1] outlets;

10. The Method for distributing irritant spray as claimed in Claim 7 wherein delivery of clear water for foam generation while keeping the irritant-water solution tank isolated is accomplished through valves branched from pump discharge pipe.