Improvements in Apparatus for the Generation of Gaseous Formic Aldehyde for Disinfecting Purposes.
Year: 1899

page_text: Date of Application, 12th Apr., 1899-Accepted, 24th June, 1899
COMPLETE SPECIFICATION.
Improvements in Apparatus for the Generation of Gaseous Formic
Aldehyde for Disinfecting Purposes.
I, LUDOVIC ROBERGE, of Anvers sur Oise (Seine et Oise), in the Republic of
France, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
'
This invention relates to an apparatus enabling formic aldehyde to be produced
in a gaseous state, at a high temperature and saturated with water.
The numerous attempts which have hitherto been made for the application of
formic aldehyde in a gaseous state to disinfecting purposes, have given uniformly
bad results, and for the following reasons:
1. Being obtained by the depolymerisation of trioxymethylene, its degree of
concentration and its low temperature resulted in the polymerisation of the
formaldehyde.
2. The concrete state of the aldehyde prevented its diffusion in the places which
it was desired to disinfect, its siccity preventing its bactericide effect.
It is for the purpose of obviating these defects that I have devised the apparatus
represented in the accompanying drawing, in which
Figure 1 is a cross-section through the generator, and
Figure 2 is a plan view of the said generator partly in section.
The apparatus consists of a steam generator G provided with Field pendulous
tubes F, in the central portion of which space is reserved for the generator C
serving for the production of the formic aldehyde.
The accessory details of the generator G are, a pressure gauge M, a valve S, a
charging cone E, a water level gauge N, and a drain cock V. This generator is
heated by a furnace of any suitable description; the means represented in the
drawing being a row of gas or petroleum jets P.
The formic aldehyde generator C comprises a cylinder e of copper, terminating
in a cap or dome c¹. The outer air enters through the pipe a which is wound so as
to form a coil A around the cylinder c and enters this latter at bat its lower
portion.
It enters the generator beneath a copper cupola 1 which is perforated and
contains the trioxymethylene to be depolymerised.
At the upper portion upon the dome care arranged; (1) A plunger tube
provided with a thermometer T, and (2) An ejector connecting with the pipe H
and with the tube communicating with the steam cock R arranged upon the
generator G.
The ejector serves to draw in the outer air which becomes saturated owing
to the action of the steam, at the same time as the formic aldehyde, and imparts
to this latter the temperature, the hygrometric degree and the velocity necessary
in order to avoid the repolymerisation of the bactericide and to obtain its perfect
diffusion in the place to be disinfected.

page_text: The generator C may be provided with handles for facilitating its transportation
from place to place and with an insulating envelope for preventing cooling.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claims:-
1. The steam generator G combined with the formic aldehyde generator.
2. The ejector I for bringing the steam produced into contact with the formic
aldehyde obtained and conveying it to the contaminated spot together with a
certain quantity of air.
3. The formic aldehyde generator C producing the same at a high temperature
and conducting it to the ejector I, where it becomes saturated with water.
4. The prevention of repolymerisation owing to the rapidity with which the
operations are conducted, resulting in the rapid production of formic aldehyde
at a high temperature, saturated with water and possessing a very high velocity
of propulsion.
5. The hereindescribed apparatus for producing gaseous formic aldehyde, con-
structed and arranged substantially as described with reference to the drawing and
for the purpose specified.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.