Improvements in the method of and apparatus for the continuos diffusion of insecticidal, fungicidal and germicidal vapours / [John Duncan Campbell].

  • Campbell, John Duncan.
Date:
1903
Catalogue details

Licence: Public Domain Mark

Credit: Improvements in the method of and apparatus for the continuos diffusion of insecticidal, fungicidal and germicidal vapours / [John Duncan Campbell]. Source: Wellcome Collection.

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    A.D. J902 N° 4053 Date of Application, 78th Feb., 1902 Complete Specification Left, 18th Nov-, 1902—Accepted, 29th Jan., 1903 PROVISIONAL SPECIFICATION. Improvements in the Method of and Apparatus for the Continuous Diffusion of Insecticidal Fungicidal and Germicidal Vapours. We, John Duncan Campbell and William Heebeet Yates both of the Irwell and Medlock Works, 185, Water Street, Manchester, Chemical Manu¬ facturers, do hereby declare the nature of this invention to be as follows: This invention relates to the method of and apparatus for the continuous 5 diffusion and application of insecticidal, fungicidal and germicidal mixed vapours, and has been devised with the object of overcoming difficulties and inconveniences which have been encountered in attempting' to economically and efficiently diffuse and apply the vapours of vaporisable fluid mixtures or solutions. Thus, it is found that if such a fluid mixture or solution be gradu- 10 ally heated in the ordinary manner, fractionation takes place and it results that the produced vapours vary in composition as the vapourisation proceeds, and that they may soon become either too strong or too weak for the purpose required. For instance, if an aqueous solution of nicotine be boiled in the usual manner^ the proportion of nicotine in the mixed vapours will vary to so large 15 an extent that very soon the proportion of the nicotine would be so small as to be useless as an insecticide, and there is no economical distribution of the nicotine. . , An attempt to obtain the continuous evolution of vapours of mixed fluids for disinfecting purposes has been suggested and consists in dropping the liquid 20 upon a heated porous substance contained in an open vessel. Although frac¬ tionation takes place, yet, the whole of the vapours being disseminated in a closed room it is possible to obtain thus a fair aggregate result. But such a method is quite useless, for the reason hereinbefore given, when the evolved vapours have to be successively applied in different limited areas or spaces, 25 since no two of the spaces would be equally treated. To overcome this and other difficulties, we have devised a method and apparatus whereby a practically instant heating and evaporating of the mixture or solution is ensured so that the evolved vapour is of constant composition. We accomplish this by causing the liquid to fall upon a heated metallic sur- 30 face constructed or prepared as hereinafter indicated, the temperature, and the rate of fall of the liquid being such as to ensure a practically instantaneous heating and evaporation from that surface. The temperature is controlled by a lamp or other usual means for heating. The metallic evaporating surface forms the bottom or part of a closed vessel 36 or chamber and is constructed of a metal or alloy which will not, under the conditions of use, chemically act upon or be acted upon by the liquid or vapours. To avoid the retardation or evaporation which would result if the liquids were permitted to assume the spheroidal state upon the evaporating surface, we roughen, indent, or corrugate it and spread thereon a number of short lengths 40 of wire held down by a layer of metallic gauze, also made of metal or alloy Jiayipg the same qualities as that of which the evaporating surface and chamber [Price S6?,j