United States Patent: 3568926

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( 17056 of 17056 )

United States Patent	3,568,926
Bowles	March 9, 1971

WATER ADDITIVE

Abstract

Material is added to a liquid jet to reduce jet dissipation by increasing the characteristic viscosity and surface tension of the liquid. Specifically, polyethylene oxide is added to water to increase the surface tension and apparent characteristic viscosity of water to decrease the dispersive effect of air on a water or liquid stream issued from a high velocity nozzle.

Inventors:	Bowles; Romald E. (Silver Springs, MD)
Assignee:	Bowles Engineering Corporation (Silver Springs, MD)
Appl. No.:	04/645,710
Filed:	June 13, 1967

Current U.S. Class: 239/10 ; 239/1; 239/310

Current International Class: B05B 7/00 (20060101); A62C 31/00 (20060101); A62c 001/02 ()

Field of Search: 239/1,10 169/1 260/2 (Epa)/

References Cited [Referenced By]

U.S. Patent Documents


3018058	January 1962	Koller
3266870	August 1966	Cianflone
3434661	March 1969	Boyle et al.
3447753	June 1969	Proctor et al.
862939	August 1907	Richardson
1873992	August 1932	Boag
3037708	June 1962	Schneider et al.
3368760	February 1968	Perry
3375976	April 1968	Stamps et al.

Other References

Industrial & Engineering Chemistry Vol 50 No 1 January 1958 pgs 8--11 Polyox.

Primary Examiner: Wood, Jr; M. Henson
Assistant Examiner: Love; John J.

Claims

I claim:

1. The method of increasing the distance of travel of a jet of liquid comprising mixing a material with the liquid to provide a fluid mixture having a greater surface tension than the liquid alone and expelling the fluid mixture under pressure from the open end of a flow passage.

2. The method of increasing the distance of travel of a jet of liquid comprising mixing a material with the liquid to provide a fluid mixture having a greater viscosity than the liquid alone and expelling the fluid mixture under pressure from the open end of a flow passage.

3. The combination according to claim 2 wherein, said material also increases the surface tension of the liquid.

4. The combination according to claim 3 wherein, the material added is polyethylene oxide and the liquid is water.

5. The method of increasing the distance of travel of a jet of liquid comprising the steps of:

adding material to said liquid at a location intermediate the ends of a confined flow path to increase the viscosity and surface tension of the liquid; and

expelling the combined liquid and material under pressure from one end of said flow path.

6. The method according to claim 5 wherein, said material is polyethylene oxide in powder form and said liquid is water.

Description

PRIOR ART

Over the years, a number of approaches have been taken to decreasing the rate of loss of velocity of a free turbulent jet due to divergence and dissipation thereof. In the prior art, most the attention has been directed to increasing the ability of the nozzle to produce a very well-defined compact jet so that the dissipation due to air resistance is reduced.

DESCRIPTION OF THE PRESENT INVENTION

The analysis of the factors effecting jet dissipation discloses that, as the velocity of the jet increases; that is, a high pressure jets are employed, the jet become sinuous and the resistance of air to the passage of the wavelets has a great effect on the decay of the jet. Sinuous or helical jet motion which, as indicated above, is produced or propagated by high velocity jets results in retardation of the steepest of these wavelets by the surrounding air. A turbulent mixing zone develops at the jet boundaries as droplets of water break away from the main stream and air becomes entrained. As the mixing zone progresses to the jet center, the jet spreads as a cone. The angles of erosion and spread of the jet depend largely on initial turbulence resulting from transverse velocity components which are a function of nozzle design and roughness of the nozzle surfaces. The prior art has primarily attempted to improve the jet range by nozzle design and use of smooth materials.

Continuing with the discussion of motion of liquids in air, any transverse turbulence in the jet is restrained only by surface tension once the jet leaves the nozzle. Thus, an increase in surface tension should restrain jet divergence.

The propagation of turbulence also depends on the viscosity of the fluid jet. Thin ligaments of very short life are pulled away from the jet by friction action of the air. These ligaments then contract into droplets under surface tension. Formation of droplets outside the main stream of the main jet contributes to jet spreading, since unshielded droplets are greatly slowed and further deflected by surrounding stagnant or slow moving air. The ability of the fluid to resist stripping of these ligaments increases with viscosity of the fluid.

The viscosity and surface tension of the water are increased in accordance with the present invention by a chemical additive; for instance, polyethylene oxide. The quantity of material required to produce a significant change in the property of a stream is quire small and percentages of one-half of 1 percent by weight of polyethylene oxide to water increased the range of a stream by almost 100 percent in a stream issuing at 93 feet per second from a .215 inch diameter tube. Photographs taken of the stream formed by the treated water show that the jet spread has been noticeably suppressed and air entrainment curtailed. Also, the wave motion of the stream is not as great in the treated water as in the untreated water due to increased surface tension.

The utility of such a system can be found in many instances, one very notable instance being in fire fighting. Polethylene oxide is nonflammable; it does not change the freezing point of water in the quantities required; and there is no perceptible change in density when the material is added to water.

It should be pointed out that the exact percentage of polyethylene oxide added to water is not critical and various amounts within practical limits may be added to the stream depending upon the initial velocity of the jet and the degree of improvement required. Instances in which 2 percent by weight of polyethylene oxide has been added to water have been encountered.

It is an object of the present invention to apply chemical additives to water and other liquids so as to improve the dynamic characteristics of a flowing stream of liquid, and more particularly, to increase the surface tension and viscosity of the liquid.

It is another object of the present invention to add small quantities of polyethylene oxide to water so as to increase the range of well-defined jet issued from a nozzle or tube.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawing, wherein:

FIG. 1 is a diagrammatic view of one embodiment of the invention in which weight pressure of a fluid stream is employed to draw the chemical additive from a tank in metered amounts into a stream of liquid; and

FIG. 2 illustrates an engine driven set of pumps for pumping both the main and treatment chemicals in proper proportions into a nozzle arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring specifically to FIG. 1 of the accompanying drawings, there is illustrated a hose generally designated by the reference numeral 1 terminating in a nozzle 2. The hose 1 is supplied with a fluid flowing at a high velocity so that a well-defined and high-powered jet of liquid may issue from the nozzle 2. Extending into the hose 1 is a pipe 3 which enters the top of the hose through a metering orifice 5. Pipe 3 is connected into the bottom of a tank 4 containing the chemical additive suitable for the particular liquid in the hose 1. In a specific example, the liquid in the hose 1 may be water and the material in the tank 4 may be polyethylene oxide, a powder. By properly proportioning the diameter or size of the orifice 5 relative to the size of the pipe 1 and the velocity of the flow therein, exact amounts of polyethylene oxide per gallon of water may be extracted from the tank 3 so that only treated water is issued from the nozzle 2. In order to maintain the powder in the tank 4 in a freely flowing condition, it may be necessary to vibrate the tank 4 as by a crystal 10. Significant improvements in stream characteristics are achieved by using less than an ounce of polyethylene oxide per gallon of water.

It may not always be desirable to use a gravity feed system for introducing powder into the hose 1 or the additive may be a liquid. Under these circumstance, a dual pump system of FIG. 2 may be employed in which case, if the additive is a powder, it is premixed with its solvent to provide a (flowable) liquid. In this system, an engine 6 drives a large capacity pump 7 and a small capacity pump 8 via a common shaft 9. The use of the common shaft to drive both pumps insures an exact weight ratio of the liquids being pumped by the two pumps regardless of variations in speed of the engine 6 with varying quantities of fluid to be delivered. The pump 7 supplies a main hose 11 while the pump 8 supplies the hose 11 via a substantially smaller hose or tube 12. The pump 7 may derive water from any source via a hose 13 while the pump 8 may derive the additive from a container or tank 14. In this situation, the pumps may be located quite a distance form the end of the hose 11; that is, the egress end thereof which, incidentally, is also true of the apparatus of FIG. 1. Specifically, even though the tube 3 of FIG. 1 is shown closely adjacent to the nozzle 2, it may be quite a distance therefrom.

Of course, premixed materials such as water and polyethylene oxide may be pumped, if desired, this being particularly true in fire extinguishers and related devices.

It should be pointed out that it is not the intention of the present invention to restrict the applicability of the invention to a fire hose environment. The features of this invention, and specifically the ability to produce water which tends to retain its shape over extended ranges of flight, has wide applicability in such environments as water cannons and related devices.

Another important feature of the use of additives which increases surface tension and viscosity is that there is a resulting increase in concentration of the jet. This effect on the jet is a value since it permits a stream to penetrate to the core of a fire of greater heat than when the additive is not employed. Also, the power of the jet to punch holes through walls is increased since an increase in jet concentration results in a corresponding increase in impact pressures.

While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention.

* * * * *

Current U.S. Class:	239/10 ; 239/1; 239/310
Current International Class:	B05B 7/00 (20060101); A62C 31/00 (20060101); A62c 001/02 ()
Field of Search:	239/1,10 169/1 260/2 (Epa)/