US 1378644 A
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J. C. BAKER.
PROCESS OF STERILIZING.
APPLICATION FILED SEPT-13,1919.
Inven or. Jf m C7 4, By Attorney S.
UNITED STATES PATENT. OFFICE.
JOHN G. BAKER, OF RIDGEFIELD PARK, NEW JERSEY.
PROCESS OF STERILIZING.
\ full, clear, and exact description.
It has been proposed and experiments have heretofore been conducted for utilizing nitrogen trichlorid (NCl as a sterilizing agent, but the processes followed and the results obtained have led to a very generally accepted belief in its uselessness for this purpose. This conclusion, I now have reason to believe, was largely based upon a fallure to produce real nitrogen tri-chlorid and a failure toproduce what purported to be this compound in a condition in which it could be practically applied and used for the purpose.
Nitrogen tri-chlorid as a chemical compound, has been long known, but because of the difiiculty of producing it, and because of its explosive character it has not been practicable to make and preserve it for any useful purpose. I have discovered, however, that as a sterilizing or disinfecting agent it has remarkable andvaluable properties, being nearly as rapidin its action as chlorin, and in cases where a large or more than the usual amount of chlorin is required to effect sterilization or disinfection, that is to say over 0.1 to 0.3 p. p. m., it may be used in its stead with great economy and success, In certain work under my supervision, for example, at Ottawa, Canada, 1.8 p. p. m. of chlorin were required for sterilization, but I accomplished the same result with 0.5 p. p. m. of nitrogen trichlorid, thus securing marked economy of operation, and I have further found that in certain liquids such as sewage or other chlorin consuming liquids, sterilization may be effected with a much less proportion of nitrogen tri-chlorid than would be required of chlorin.
My discovery that nitrogen tri-chlorid is a valuable and eificient sterilizing agent owes its value and importance, moreover, to a process or method which I have devised for producing and using it, which process involves not only a novel manner of making the compound, but its immediate application or use for sterilizing, as it may not be practically accumulated -or stored, and ac- Speeification of Letters Patent.
Patented May 1'7, 1921.
Application filed September 13, 1919. Serial No. 323,650.
cording to my invention I proceed as followsz I dissolve chlorin gas in water in the proportion of 0,1 to 0.5% of chlorin to water, and pass this aqueous solution through a body of crushed limestone until the chlorin 1s all converted to hypochlorous acid and the hydrochloric acid (HCl) all neutralized. The reaction may be thus expressed:
The first named reaction is reversible, and using the quantities specified does not go to completion, but may be completed by the neutralization of the hydrochloric acid by the action of the limestone. This acid after conversion to weak carbonic acid (H CO -will become finally converted'by prolonged contact with the limestone to calcium bicarbonate (Ca (I-IC'O The active material in the resulting solution is hypochlorous acid (HOCl), which is thus obtained free from chlorin (C1,) or hydrochloric acid (HCl), and in concentrat on sufficient for economical working condit ons. The solution resulting from this act1on of the limestone is then mixed in measured quantity with ammonia or any solut1on containing a known quantity of ammonia or ammonium compounds such as ammonium hydroxid, chlorid or sulfate or other compound, and the mixture results in the formation N01,), as shown by the following equation:
NILOH 3HOOl-+NC1, e1 0 OI In these equations the proportion by weight of available chlorin to ammonia (NH,,) is 12.5 to 1, and the resulting product may be used under proper condition, as I shall hereinafter more fully set forth as a highly useful and eflicient sterilizing agent for many purposes. V
In order that my process may be successfully carried out, I have annexed hereto a drawing which illustrates diagrammatically an apparatus by means of which the invention may be practised.
I use containers '1, 1 of chlorin which passes as may be desired or controlled to a chlorin meter 2; F rorm there the gas -passes through acheck valve 3 to an injector 4, by
of nitrogen tri-chlorid means of which it is passed into a regulated flow of water entering through a valve controlled inlet 5 in a pipe line 6 when it combines with the water to form a chlorin solution.
This solution is introduced into a tower or extended chamber or receptacle 7 containing crushed limestone, and by the action of which it is converted into hypochlorous acid. This latter solution is taken off by a pipe 8, an overflow pipe 9 being provided for use in case of need, and by such pipe it is delivered into a constant level box or chamber 10.
' From this latter it is passed in regulated quantity 'into a mixing chamber 11 by a pipe 12, provided with valves and a gage, and entering the top of said chamber.
I also use an ammonia tank 13 for con-= taining the ammonia or ammonium solution and connect this tank by a pipe 14 with a constant level box or receptacle15 from which a pipe with valves and a gage to regulate the flow of ammonia leads into the top of the mixing chamber.
To facilitate the mixture of the two in gredients a pipe 16 with a water jet enters the mixing chamber and the resulting solu-' tion is led off by a pipe 17 to the water, sewage or other materlal which is to be sterilized in the ordinary or any well-known manner.
All parts of this apparatus are of wellknown character and 'are widely used in other. processes, particularly those involving the use of chlorid as a sterilizing agent.
The resulting solution, if the rates of supply of the hypochlorous acid and ammonia be properly determined and regulated, will contain nitrogen tri-chlorid in an aqueous solution, and it may be used for sterilizing water, milk, sewage, or other articles or materials. The compound is exceedingly .volatile and by spraying or otherwise subdividing the solution it may be driven off as a gas, and utilized in this condition as a sterilizmg agent, especially for solid articles, such as fruits and the like,
I have. not shown any special mechanism 2. The process herein described of sterilizing which consists in producing ,hypochlorous acld, m1x1ng therewith ammonia or ammonlum compounds in measured roportions and utilizing the solution of n1trogen-tri-chlorid resulting therefrom immediately as produced as a sterilizing agent.
3. The process. of sterilizing herein described, which consists in continuously bringing together during the period and at the rate of the use of the product the materials necessary for producing an aqueous solution of nitrogen trichlorid, forcing air through the solution as produced and applying the gas as the sterilizing agent.
4. The process of sterilizing herein described which consists in mixing in meas ured quantities hypochlorous acid and ammonia or ammonium compounds and utilizing the nitrogen tri-chlorid resulting from such mixture immediately. as produced as the sterilizing agent.
In testimony whereof I hereunto aflix my signature. JOHN C. BAKER.