US 2978152 A
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E. G. BATTY April 4, 1961 AEROSOL CAN Filed Jan. 15, 1959 INVENTOR Edward 6 Batty ATTORNEY state at the nozzle.
United States atent AEROSOL CAN Edward G. Batty, 8611 Hartsdale Ave., Bethesda 14, Md.
Filed Jan. 15, 1959, s81. No. 787,093
4 Claims. (Cl. 222-394) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.
This invention relates to an apparatus for improving the operability pressurized aerosol containers.
More specifically the object of this invention is to prevent freezing and clogging of the nozzle mechanisms due to the rapid expansion of the liquid propellant into the gaseous state which takes place at the nozzle.
Other objects of my invention will be seen from the following description and from the accompanying drawing which shows my improved aerosol container mechanism.
Pressurized aerosol container mechanisms are employed for many types of operations, and one of these is for the decontamination of materials and small areas where it is impossible to decontaminate by other means, such as by an autoclave process. Sterilization by means of aerosols from pressurized aerosol containers proved to be advantageous because of the ease of which these containers can be employed in most any' type of situation. For example, the decontamination of an article in a submarine. could easily be accomplished by using a pressurized aerosol container which is small and easy to transport. 7
' A mixture of 11% ethylene oxide, 44.5% dichlorodifiuoromethane and 44.5% trichlorofluoromethane was found" to produce an efiective non-flammable decontaminant. Since all three of these substances are gases at room temperature, all will vaporize when entering the atmosphere. this mixture of.liquids would expand into the gaseous would be obtained from the surrounding atmosphere, which generally would contain a considerable amount of water vapor. This water vapor would condense and freeze on the nozzle thereby clogging the parts and hindering the operation. The higher the internal pressure, the greater is the tendency of the nozzle to freeze because of the extreme velocity at which the propellant liquids exit into the atmosphere.
, To overcome this freezing effect, I have .devised an apparatus whereby the exit speed is reduced, and wherein little or no expansion takes place at the nozzle thereby preventing any clogging ofthe nozzle.v
When' using a regular aerosol container,
Eitented Apr. 4, 1961 which has an insert plug 20 attached to it at one end.
The insert plug has an aperture 22 which permits the flow of the liquid propellant into the expansion chamber. The expansion chamber, which is shown as a spheroid, but which can be made in any desirable shape, is connected by means of a suitable connector 24 to the flexible tube 26 which in turn is connected to the valve mechanism. It is important that the chamber be made of a material which will not deteriorate when in contact with the liquid contents, and which has high heat transfer properties. Metallic substances such as steel, copper, aluminum etc., are good examples of materials with these desirable properties.
The insert plug is advantageous because it prevents freezing at the aperture. It is necessary that the plug be made of material which has low heat transfer properties, such as certain plastics and, of course, it too must be compatible with the liquid contents.
In operation, the valve is opened thereby lowering the pressure within the expansion'chamber. The liquid contained in the chamber expands into a gas and is released through the nozzles. The heat necessary for this expansion or change of state is taken from the surrounding liquid and is conducted through the chamber walls. Since the inside plug is made of low heat conductive materials, only a small amount of heat will be conducted through this area. This will prevent any freezing or solidifying of the surrounding liquid which would tend to clog the passage into the chamber. In certain situations, the insert plug may not be required, but this The heat needed for vaporization The method of operation consists of expanding the liquid into the gaseous state within a chamber which is submerged in the liquid propellant and then allowing the already expanded materials to exit throughthe nozzle. The heat which is necessary for the expansionof the .liquids into the gaseous state is obtained from the liquid which surrounds :the chamber. 7 pe'rature' of the surrounding liquid islowered which In so doing, the temcauses the internal pressure and the exit velocity of the propellantsto belowered; The lowering of the internal pressure is particularly important when the outside depends on the conditions and the materials that are employed; that is, the liquid propellents and the expan- Other means may be used in tion of chamber near the aperture with a low heat conductive plastic.
My device will work in all positions because the heavy expansion chamber, being connected to a flexible tube, will always be at the bottom of the liquid body.
From the above disclosure it is seen that the freezing problem has been solved by my apparatus. The principles set forth in my invention can be employed in solving other problems in this field, such as the controlling of the internal pressure of the propellant and exit flow rates of the materials to be disseminated.
1 claim: 1. An improvement for a pressurized aerosol container for preventionnof valve freezing that contains a liquid fill, wherein said liquid fill consists of gases at normal room' temperatures and atmospheric pressures that have been compressed into a liquid state, a valve mechanism,
at least one dispensing outlet nozzle, a valve activator, and a flexible tube extending from said valve mechanism to the inside bottom of said container, said improvement comprising an expansion chamber having plural openings, one opening being connected to the end of said flexible tube, and a second of said openings being submerged in the liquid fill no matter what position the container is in, an insert 'plug having a small aperture extending therethrough, fitted in the second of said chamber openings, said insert plug being made of a material having relatively low heat transfer properties, said expansion chamber being made of a material having relatively high heat transfer properties and also having a density greater than the density of said liquid fill, and being chemically compatible with said liquid fill.
2. The apparatus of claim 1 wherein the insert plug is made of a plastic material.
3. The apparatus of claim 1 wherein the expansion chamber is made of a metallic substance which is inert to the liquid fill.
4. The apparatus of claim 3 wherein the metal chamber is spherical in shape.
References Cited in the file of this patent UNITED STATES PATENTS Schlosser Nov. 22, 1938 Thompson Dec. 1, 1946 Engstrum Dec. 18, 1956 Urlaub Jan. 22, 1957 Kiraly Oct. 29, 1957