US 2392936 A
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Description (OCR text may contain errors)
Patented Jan. 15, 1946 "it": FOAIW SOLUTION AND METHOD OF USING S ration of New Jersey Application July 2, 1,942;
Serial No. 449,520
This invention relates to improvements in methods for ate-contaminating restricted areas which have been subjected to warfare chemicals, as in the case of a. gas attack, and the product.
An object of this invention is to provide a novel oxidizing foam producing solution capable of being formed into a cloud or blanket of foam for the purpose of covering a restricted area which has been subjected to poison gases, solutions or solids and the like for the purpose of blanketing those areas and oxidizing the poisonous gases, solutionsor solids to an innocuous condition.
Another object of this invention is the provision of a novel method of de-contaminating restricted areas over which a poisonous gas, solution or solid has been spread by the application thereover of a dense type blanket of foam having mixed therein an oxidizing or other agent capable of oxidizing, neutralizing or otherwise destroying the harmful character of the poisonous material.
Other and more specific objects of this invention will become apparent from the following description thereof.
This invention resides substantially in the combinations of materials and the steps and series of steps all as detailed in the following specification and defined in the appended claims.
As this description goes forward, it will become apparent that the subject matter of the invention is applicable in de-contamination work irrespective of the types of poisonous chemicals to be ren-, dered innocuous. In chemical warfare the polsonous materials are employed in various forms, as for example gases, liquids or solids, and are employed to produce various forms of distress in persons coming in contact therewith. Of the various warfare chemicals employed, the veslcant gases, such as mustard gas, are difilcult to dispose of. Mustard gas is relatively heavy and tends to fall to the ground and condense on surrounding objects. This is a characteristlc of other dangerous warfare chemicals advantage of which is.
taken by this invention. With respect to mustard gas the most approved method of rendering it harmless at the present time is to spread bleaching powder over the contaminated surface and then by careful mechanical manipulation to scrape it up in piles and cart it away. The bleaching powder oxidizes mustard gas to more or less harmless products. It is apparent, however,
that this is a crude method of de-contamlnating inflic ed areas in addition to which it is, of course, a se uce of possible injury to the de-contaminaior. workers.
in accordance with the concept of this invention, it is proposed to incorporate the neutralizing agent, as for example an oxidizing compound, in a thick, dense. heavy blanket of foam forming materials which may be sprayed or otherwise spread over a contaminated area. Such 'a blanket excludes the air from contact with the mustard gas; prevents the evaporation of the mustard gas from the contaminated areas and puts a protective coating over them which minimizes the possibility of contact therewith.
Another very important advantage of this procedure is that the wet blanket oi foam produces an efiective contact between its contained neutralizlng or oxidizing agent and the gas or other chemical to be reacted therewith. The result is that the poisonous material is more quickly, effectively and completely neutralized, oxidized or otherwise rendered harmless. Since foams of this type commonly contain wetting or spreading agents, the contained neutralizing or oxidizing compounds in the foam are effectively spread over the material to be die-contaminated. This is a particular advantage in the case of poisonous materials such as mustard gas which is oily and therefore is difilcult to bring into intimate contact with the oxidizing agent. It is apparent that this method is much more efiectlve than that of spreading bleaching powder which is in contact with the poisonous materials in the form of small particles and thus has a limited action. Likewise bleaching powder, unless very thickly spread over the contaminated area, has no blanketlng eflect.
A still further object of the invention is found in the fact that the blanketed area gives a visible indication of'the presence of the persistent form of the areas which have been treated.
An additional advantage of the invention is found in the tact that the blanket follows the contours of the ground and goes down into crevices and other depressions so as to contact with poisonous materials which have settled therein. Of course, it is again noted for emphap sis that one of the most important advantages of the invention is the fact that such a blanket prevents the poisonous material from reaching the atmosphere and injuring persons in the viclnity as well as the operators of the de-contaminatlon equipment.
It will be apparent that the novelty of this invention does not reside in the Specific elements of the foam forming solution or in the specific neutralizing or oxidizing compounds employed. However, several examples of suitable solutions will be set Earth for the salts of completeness.
A suitable foaming mntture consists of a wamr paste, a stable protein degradation product to act as an emulsion stabilizer and various other ingredients with which we have no particular concern here, such as those commonly employed to prevent corrosion, to control the viscosity of the foam, to prevent its freezing and to minimize putrefaction of the contained protein. Such a foaming solution can be used with either fresh water or sea water. Another suitable foaming sotion would be the same as that set forth above with the exception that in place of sulfated lauryl alcohol a mixture of potassium, triethanolamine, and morpholine laurates can be used. This foaming solution can only be used in admixture with fresh water or hard water. However, this second foaming solution can also be used with a suitable quantity of sulfated lauryl alcohol to slst for considerable periods of time.
Any suitable neutralizing or oxidizing compound may be mixed with the foam forming solution prior to the formation of the foam, such as for-example sodium chlorite, NaClOz; a liquid bleach such as Javelle water, NaOCl; the bleaching powder having the approximate composition CaCl(OCl); or calcium hypochlorite, Ca(ClO 2. A suitable quantity of such an agent is mixed into cium hypoehlorite 62.5 Bleaching powder containing 36% of active chlorine 45.1 Water 1250.0
After filtering this solution may be aspirated as before to provide a suitable blanket over a contaminated area. Of course, sodium hypochlorlte can be used in the above formula in place of the the foam forming solution in the proper proportion. The following are a fewexamples of the final solution with the proportions of the ingredients as indicated by way of example:
. Grams Foam solution 62.5 10% technical sodium chlorite solution 125.0 Wate I 1250.0
When a solution of this type is aspirated and ejected through a nozzle it issues in the form of acid will be suitable.
Another suitablesolutlon consists of Grams Foam forming solution 62.5 Javelle water containing about 15% available chlorine 108.5
when such a solution, is aspirated and elected through a nozzle it gives copious quantities of foam and liberates considerable quantities of chlorine over relatively long periods of time.
It is likewise again emphasized that other suitable compounds are available to be substituted for the exidizing agents herein disclosed. We do not, therefore, desire to be strictly limited to the details of this disclosure but rather to the scope area a dense persistent blanket of foam having an oxidizing agent distributed therein.
3. A method of de-contaminating an area upon which a poisonous substance has been spread which comprises forming and spreading over said area a dense persistent blanket of foam having a hypochlorite distributed therein.
4. A method of de-contaminating an area upon which a poisonous substance has been spread which comprises forming and spreading over said area a dense persistent blanket of foam having a chlorite distributed therein.
5. A method of de-ccntaminating an area over which a poisonous chemical has been spread which comprises aspirating a mixture of a foam forming solution and a neutralizing agent to cause the mixture to foam and spreading the foam in the form of a. blanket over said area.
6. A method of de-contaminating an area over which a poisonous chemical has been spread which comprises aspirating a mixture of a foam forming solution and an oxidizing agent to cause the mixture to foam and spreading the foam in the form of a blanket over said area.
"I. A method of de-contaminating an area over .which a poisonous chemical has been spread which comprises aspirating a mixture of a foam forming solution and a hypochlorlte to cause the mixture to foam and spreading the foam in the form of a blanket over said area.
8. A method of de-contaminating an area over which a poisonous chemical has been spread which comprises aspirating a mixture of a foam forming solution and a bleaching agent to cause the mixture to foam and spreading the foam in the form of a blanket over said area.
HARRY E. MA'I'IIN. LEWIS G. M. TIMPSON.