Improvements in the Disinfection and Deodorization of Sewage and in the Apparatus for Preparing and Applying the Disinfectant.
Year: 1891

page_text: Date of Application, 17th Feb., 1891
Complete Specification Left, 17th Nov., 1891-Accepted, 19th Dec.. 1891
PROVISIONAL SPECIFICATION.
Improvements in the Disinfection and Deodorization of Sewage
and in the Apparatus for Preparing and Applying the
Disinfectant.
We, ALEXANDER MCDOUGALL of 17 Belmont Street, Southport, Gentleman,
and JAMES JONES MELDRUM, of 25 Cathedral Yard, Manchester, Engineer, both
in the County of Lancaster, do hereby declare the nature of this invention to be as
follows:--
Our invention relates to the deodorization and disinfection of sewage by the
application of sulphurous acid gas and consists in a method of preparing and
applying the gas to the sewage. The prejudicial and offensive products of the
decomposition of sewage matter are mainly compounds of sulphur and phosphorous
with hydrogen and sulphur or phosphorous compounds with alkalies or ammonia.
Sulphurous acid gas or sulphurous acid decomposes these products with the
precipitation of sulphur and phosphorous or the formation of hyposulphites or hypo-
phosphites when the sulphur or phosphorous compounds are present in alkaline
solution, and we utilize this property to treat sewage and render it innocuous and
inoffensive. In one mode of carrying our invention into effect we generate sulphur
dioxide by the combustion of sulphur, pyrites or spent oxide in a suitable furnace
and we conduct the mixed gases proceeding from this furnace, which gases contain
nitrogen and excess oxygen as well as sulphur dioxide, to an injector actuated by a
steam jet. This injector draws the mixed gases containing sulphur dioxide from
the furnace and discharges them into a pipe laid along a trough channel or vessel
containing the sewage. The pipe is perforated at intervals along its length and the
gases are discharged at the holes and bubble up through the liquid coming into
intimate contact with it and dissolving the sulphur dioxide (SO) to form a solution
of sulphurous acid which acid acts upon the noxious compounds and renders them
inodorous as described. In order to increase the surface of contact between the
sewage liquid and the gases forced into it we prefer to place baffle plates above the
holes in the pipe laid in the trough or channel. These baffle plates detain the gases
longer in contact with the liquid than would otherwise be the case and may be
slightly inclined and provided in any required numbers.
We control the rate of supply of the gases containing sulphur dioxide with great
accuracy by the aid of convenient cocks or valves controlling the supply of steam
to the injector. The injector is constructed of suitable metal or material to resist
the action of the hot sulphurous acid gas among other metals we find that an alloy of
antimony and lead answers well; earthenware or porcelain may however be used
and similar acid resisting materials may be used for the pipe discharging under the
Bеwage
In some cases we find that the termination of the action of the sulphurous acid
gas is conveniently indicated by the change of the liquid from an alkaline to an
acid reaction.
T 11
1
" 17 "

page_text: COMPLETE SPECIFICATION.
Improvements in the Disinfection and Deodorization of Sewage
and in the Apparatus for Preparing and Applying the
Disinfectant.
.
We, ALEXANDER MCDOUGALL of 17 Belmont Street Southport, Gentleman,
and JAMES JONES MELDRUM, of 25 Cathedral Yard, Manchester, Engineer, both
in the County of Lancaster, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
Our invention relates to the deodorization and disinfection of sewage by the
application of sulphurous acid gas and consists in a method of preparing and
applying the gas to the sewage. The prejudicial and offensive products of the
decomposition of sewage matter are mainly compounds of sulphur and phosphorous
with hydrogen and sulphur or phosphorous compounds with alkalies or ammonia.
Sulphurous acid gas or sulphurous acid decomposes these products with the precipi-
tation of sulphur and phosphorous or the formation of hyposulphites or hypo-
phosphites when the sulphur or phosphorous compounds are present in alkaline
solution, and we utilize this property to treat sewage and render it innocuous and
inoffensive. We carry our invention into effect in one mode illustrated in the
accompanying sheet of explanatory drawings in which we employ sulphur dioxide
generated by the combustion of sulphur, pyrites or spent oxide in a suitable furnace A
and we conduct the mixed gases proceeding from this furnace, which gas contain
nitrogen and excess oxygen as well as sulphur dioxide, to an injector actuated by a
steam jet. This injector B draws the mixed gases containing sulphur dioxide from
the furnace A and discharges them into a pipe D laid along a trough, channel or
vessel E containing the sewage. The pipe is perforated at intervals d d along its
length and the gases are discharged at the holes and bubble up through the liquid
coming into intimate contact with it and dissolving the sulphur dioxide (SO,) to
form a solution of sulphurous acid which acid acts upon the noxious compounds and
renders them inodorous as described. In order to increase the surface of contact
between the sewage liquid and the gases. forced into it we prefer to place baffle
plates F above the holes in the pipe D laid in the trough or channel.
These baffle
plates detain the gas longer in contact with the liquid than would otherwise be the
case and may be slightly inclined and provided in any required numbers.
We control the rate of supply of the gases containing sulphur dioxide with great
accuracy by the aid of convenient cocks or valves controlling the supply of steam
to the injector. The injector B is constructed of suitable metal or material to resist
the action of the hot sulphurous acid gas; among other metals we find that an alloy
of antimony and lead answers well; earthenware or porcelain may however be
used and similar acid resisting materials may be used for the pipe discharging under
the sewage.
In some cases we find that the termination of the action of the sulphurous acid
gas is conveniently indicated by the change of the liquid from an alkaline to an
acid reaction.
In the accompanying drawing
Figure 1 is an elevation and Figure 2 a plan showing the manner in which we
arrange any ordinary furnace A with our injector B. The injector being shown in
detailed sectional elevation at Figure 3 and in end elevation in Figure 4.
The steam we pass through a pipe cand cock c² to the nozzle c, the connection
to the furnace cover being made from the branch pipe A', and the outlet pipe D
being connected on the branch B'.
We sometimes introduce any ordinary stop, sluice or throttle valve on to the outlet
pipe D for the purpose of regulating the amount and extent of the discharge to suit
any particular requirement.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
(1) In apparatus for treating sewage or other offensive liquids, the use of free
sulphur di-oxide applied in such manner as to dissolve in the liquid to be disinfected
or deodorized, substantially as hereinbefore described..
(2) In apparatus for treating sewage or other offensive liquids by sulphur
di-oxide, an arrangement of perforated pipes and deflecting plates to cause the gases
to come intimately into contact with the liquid so as to dissolve readily, substantially
as hereinbefore described.
(3)-In treating sewage and other offensive liquids with sulphur di-oxide the use
of a steam jet, exhauster or blower consisting of an annular or central nozzle and a
combining cylinder or cone with or without a diverging outlet; such exhausters or
blowers being employed to propel air to or exhaust the gases of combustion from a
furnace burning sulphur, whence the mixed gases containing sulphur di-oxide pass
to the liquid, as and for the purposes hereinbefore described.
(4) The apparatus herein before described and illustrated in the accompanying
drawings for disinfecting and deodorizing liquids.
Dated this 16th day of November 1891
CLERK & MARKS,
13, Temple Street,. Birmingham, Agents for the Applicants.