IMPROVEMENTS IN THE TREATMENT OF PROVISIONAL SPECIFICATION
Year: 1882

page_text: LETTERS PATENT to James Young of Kelly in the County of Renfrew
North Britain for an Invention of "IMPROVEMENTS IN THE TREATMENT OF
PROVISIONAL SPECIFICATION left by the said James Young at the Office
of the Commissioners of Patents on the 27th July 1882.
JAMES YOUNG, of Kelly, in the County of Renfrew, North Britain, " IMPROVE-
MENTS IN THE TREATMENT OF SEWAGE,"
This Invention which relates to Improvements in the treatment of Sewage has
for its object to obtain ammonia and other products therefrom, and to render the
residue less offensive.
The Invention consists in distilling off a portion of the sewage, the distillate
containing a greater proportion of ammonia than the original sewage.
In practising the Invention I distil the sewage either by itself or mixed with
Lime, and either under high or atmospheric pressure, or with the atmospherio
pressure removed or partly removed.
The apparatus I use for this purpose consists of a series of close vessels so
arranged that the vapour and gases driven off from the first pass into the second
and those from the second into the third and from the third to the fourth and so on
as far as may be found convenient and economical The operation is assisted by
passing through a current of air along with the steam-the heat from the spent
liquor to be used to heat the sewage to be treated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Young in the Great Seal Patent Office on the 27th January
1883.
JAMES YOUNG, of Kelly, in the County of Renfrew, North Britain,
MENTS IN THE TREATMENT OF SEWAGE.
"IMPROVE-
My said Invention, which relates to Improvements in the treatment of sewage, has
for its object to obtain ammonia and other products therefrom and to render the
residue less offensive.
The Invention consists in distilling off a portion of the sewage either by simply
boiling the sewage or by passing steam through it at the boiling point, resulting in
the escaping steam or distillate containing a greater proportion of ammonia by
weight than the original sewage.
In practising the Invention the boiling temperature is or may be lowered by more
or less complete removal of the atmospheric pressure so that the operation is
conducted at a low pressure or in a partial vacuum-The distillation may however
be conducted at the ordinary pressure of the atmosphere or at higher pressures, and
the exhausted liquid (that is to say the liquid from which the ammonia has been
driven off) may be used to heat further quantities of sewage for similar treatment.
Before treating the sewage water by my process I may add lime or other suitable
alkali or alkaline Earth to it in sufficient quantity to precipitate the solid matter of
the sewage and liberate the ammonia, after which the liquid may be decanted and
the water only operated upon but this is not in all cases necessary as the sewage
may be treated by my Invention without decanting or even precipitating the solid
matter.
The apparatus employed for the purpose of separating and collecting the
ammonia may be arranged in various forms having for their object the complete
exhaustion of the sewage of, and the saturation of the steam with ammonia, but I
prefer to carry out the operation in one of the methods described in the Provisional
Specification lodged by me on the 26th day of January A.D. 1883, together with
my application for Letters Patent of that date. These methods may be described
follows:-
I arrange a number of closed vessels in continuity or circular series and pass the
steam through each of them in succession until it has completed the circuit.-
The steam in bubbling through the liquid becomes more or less saturated with
ammonia, when it may be either condensed per se or passed into acid to extract
the ammonia.-When the vessel into which the steam first enters is sufficiently
exhausted, it is emptied, refilled with fresh sewage, and made the last of the series,
while the vessel which was second before, becomes the first. This arrangement
ensures that the freshest steam, comes into contact with the weakest liquid, and
the most highly charged steam passes through the strongest liquid, so fulfilling the
most favorable conditions for exhaustion of the sewage and saturation of the
steam.
The process may also be modified in the way described in the same Provisional
Specification so as to render it continuous by introducing a constant supply of
sewage into the vessel last in the series (where the saturated steam is allowed to
escape) and withdrawing an equal quantity from the vessel first in the series
(where the steam is admitted) while each vessel beginning with the last, is con-
nected with the one next it by a pipe leading from just below the water level of
the former to the bottom of the latter, the liquid and steam in such an arrangement
consequently passing in opposite directions. In adjusting the apparatus allowance
must be made for the difference of water level in each vessel as this will be raised

page_text: from one end of the series to the other proportionally to the dip of the steam-pipes
below the surface of the liquid, and the pressure of the steam itself. By increasing
the area of the steam-pipes this pressure is reduced to a minimum. I may employ
air-pumps or fans in the connecting pipes to draw off the steam from each vessel
and drive it into the next.
I have appended hereunto a sheet of Drawings on which I shew an apparatus
consisting of a series of vessels and connections by means of which this continuous
boiling and distillation of the sewage in a partial vacuum can be conveniently
carried out. In actual practice these vessels will be made of metal, concrete, or
other suitable material of strength sufficient to withstand the external pressure.
The apparatus I have shewn consists of four upright cylindrical vessels respectively
marked A, B, C, and D, but there may be a greater or less number of such vessels
with the various pipes and connections to be hereafter described. A sufficient
vacuum having been obtained in the apparatus by means of a vacuum pump com-
municating with the pipe N, leading from the vessel A, the sewage is caused to
flow into the apparatus through the inlet E. The sewage rises in the vessel A,
until it reaches the level of the stand-pipe or overflow F, down which it falls and
fills the vessel B, up to the height of its overflow G, down through which the
sewage again falls and fills the vessel C, up to the height of its overflow H, when
the sewage again falls therethrough and fills the vessel D, up to the height of its
stand or overflow pipe I.-It will be observed that the level of the stand-pipe or
overflow F, is higher than the overflow or stand-pipe G, that G, is higher than H,
and H, higher than I, so that the level of the liquid in the vessel A, is maintained
higher than that in the vessel B, the level in B, higher than that in the vessel C,
and the level in C, higher than that in the vessel D.-The object being to over-
come the steam-pressure produced by the dip of the steam pipes below the level
of the liquid in each vessel. Into the upper part of the vessel D, a steam inlet
pipe J, passes, the pipe dipping a convenient distance below the level of the sewage
therein; a similar pipe K, leads from the vessel D, to a similar distance below the
level of the sewage in the vessel C, from the top of which another similar pipe L,
leads, that likewise dips into the sewage in the vessel B, from which another such
pipe M, leads and dips into the sewage in the vessel A. The upper part of the
vessel A, is connected by the pipe N, to a vacuum pump.
The action of the apparatus is as follows:-The several vessels A, B, C, and D,
being more or less exhausted of air, and charged with sewage as herein before
described and shewn on the accompanying Drawing-The liquid in each vessel is
heated to the boiling point or to a temperature near to the boiling point, corre-
sponding to the pressure at which the vapour therein is intended to be, if it has
not been introduced into the vessels at the proper temperature. This temperature
will be lowered in proportion to the vacuum to be obtained.-Stem is then
admitted to the vessel D, through the steam inlet J, and passing through the liquid
in each of the four vessels, D, C, B, and A, consecutively by the pipes J, K, L,
and M, finally leaves the apparatus by the steam outlet N, in the direction of the
vacuum pump.
The ammonia contained in the sewage as well as other volatile substances are
carried out of it by the steam or low pressure aqueous vapour passed through the
vessels A, B, C, and D, so that whilst the sewage in the vessel A, contains the
maximum quantity of the aminonia and other substances removed by the passing
of aqueous vapour through the vessels, the vessels B, C, and D, contain respec-.
tively less and less of the ammonia and such substances so separated, and the
number of vessels should be such that the liquid in the last vessel thereof namely
the vessel D, should be as far as convenient deprived of the ammonia and those
substances which pass off with it, while a continuous current of steam is passing
through the apparatus in the manner described. A continuous supply of sewage,
preferably heated, to the temperature at which it will boil at the diminished
pressure under which the operation is conducted, is introduced into the vessel A,
through the inlet E, and an equal amount withdrawn through the outlet O, by

page_text: means of a pump or otherwise. From the arrangement of the apparatus which I
have now described and shewn on the accompanying Drawings it will be obvious
that the sewage flows continuously through it in one direction in the bottom parts
and stand pipes of the several vessels whilst low pressure steam passes in the
opposite direction in the upper parts of such vessels and the several dip-pipes
J, K, L, and M, wherein a partial vacuum is maintained as hereinbefore described.
The directions of flow of the sewage and steam are indicated by the arrows on the
accompanying Drawing.-The several dip pipes are made of large diameter for the
purpose of providing sufficient room for the low pressure steam or aqueous vapour
to pass through. The ammonia and other substances pass off with the aqueous
vapour to a condenser or to other collecting apparatus whilst the uncondensed
gases pass off to the vacuum pump which is preferably kept in continual
operation. The steam may be passed through acid to extract the ammonia.-And
after passing the vacuum pump, the gases may be submitted to the action of heat in
a furnace or retort so as to destroy their noxious properties.
The heat of the exhausted sewage, as well as that of the escaping steam may
be more or less completely utilized by causing it to heat fresh quantities of cold
sewage.
It is not necessary that the apparatus above described should be employed or
that the operations should all go on simultaneously but it will be much more
economical if this is done.-The process may however be conducted by passing
steam through one vessel and condensing it in another (preferably containing cold
untreated sewage) and then when the latter is sufficiently rich in ammonia
repeating the process upon it.
A mixture of steam and air may also be used in any of the foregoing cases, where
steam alone has been specified.
By means of this method I am able to operate upon the sewage at as low a
temperature as from 60° to 90° Fahrenheit, and thereby greatly economize the
consumption of fuel necessary for treating the sewage. This is attained by
reducing the pressure of the vapour in the vessel to about half an Inch of mercury.
Having now described and particularly ascertained the nature of my said
Invention and the system, mode or manner in or under which the same is or may
be used or practically carried into effect I would observe in conclusion that I do
not limit myself to working my Invention in the manner hereiubefore described
and shewn upon the annexed drawing, but what I consider to be novel and
original and therefore claim as the Invention secured to me by the hereinbefore
in part recited Letters Patent is :-
First. The treating of sewage by boiling it or by treating it with steam or
steam and air at or near the boiling point at a diminished atmospheric pressure or
at the atmospheric or higher pressures so that the ammonia is eliminated and
subsequently condensed and collected substantially as herein before described.
Second. The application of the process of successive distillation above described
to sewage water after the solid matter has been thrown down and removed
substantially as herein described.
Third. The above described method of treatment of sewage water at low
temperature such as 60° to 90° Fahrenheit by the reduction of the pressure in the
vessels to a sufficient degree substantially as herein described.
In witness whereof I the said James Young have hereunto set my hand
and seal this Twentieth day of January in the year of Our Lord one
thousand eight hundred and eighty three.