Improvements in Tanks or Vessels and Apparatus used in the Purification of Sewage and other Foul Waters by Precipitation, and in the Treatment of the Sludge obtained in such Process.
Year: 1892

page_text: Date of Application, 31st May, 1892
Complete Specification Left, 28th Feb., 1893-Accepted, 29th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Tanks or Vessels and Apparatus used in the
Purification of Sewage and other Foul Waters by Precipitation,
and in the Treatment of the Sludge obtained in such Process.
I HAMOR LOCKWOOD of 7 Chapel Walks Manchester in the County of
Lancaster, Manufacturing Chemist, do hereby declare the nature of this invention
to be as follows:-
In the purification of sewage by means of chemical substances, a precipitate is
produced which has hitherto been allowed to settle at the bottom of the tanks, and
then let off, and either carried out to sea, when that is practicable or pressed by
means of specially constructed presses, which latter process is costly, and the
resulting cake in all cases of low manurial value, and (in the case of the use of any
of the forms of iron as a precipitant) of no value whatever.
As thrown down and settled in open tanks ready for running off, this precipitate
holds about ninety per cent. of water. My improvements consist in pumping or
allowing this sludge to run into closed tanks or vessels of special construction as
hereafter described, whereby it can be subjected to the action of a vacuum which
removes a great part of this ninety per cent. of water and gives the remaining sludge
a consistency sufficient to stand the second part of the process, (which is conducted
in the same vessel) namely, subjecting it to an air pressure by means of an air
pump of one hundred pounds to the square inch or such other pressure as may be
consistent with the strength of the vessel, or may be most economical in the
circumstances of each particular case. From this vessel the hard pressed sludge
is conveyed to a destructor or cremator, fed by means of fluted rollers or otherwise,
the sludge travelling through the flame by which means the organic matter is
totally destroyed and rendered innocuous while the mineral matter may be used for
concreting, mixing with mortar, or filling up waste land or any suitable purpose
without the slightest danger to the health of the inhabitants of the neighbourhood
and without having caused any nuisance in the process.
In carrying out this invention I take a strong iron cylinder or iron cylinders
(the size depending on the amount of sludge to be treated and the pressure
required) and inside this I place a perforated iron cylinder of smaller diameter to
the inner surface of which I attach a strong canvas lining acting as a filter. The
flanges at the ends of this double cylinder are faced and fitted with plates covering
the ends, of such strength as will withstand the pressure to be used. The sludge
from the tanks is conveyed by means of pipes into the inner or perforated cylinder
and the vacuum applied till no more water can be extracted. When this happens
a further quantity of sludge is run in until the inner cylinder is full of sludge
with so much water removed as can be the power of the vacuum. Then the air
pump is put on and worked until the requisite pressure has been applied and no
more water is extracted. The water is removed from the cylinder by means of
the same pipe which is used for obtaining the vacuum. The end of the cylinder is
then removed, the sludge dug out, the vessel washed and the end replaced when it
is ready for use for a further batch.
The sludge is taken to a cremator, a convenient and economical fuel for which I
find to be crude creosote oil, or common petroleum, or other cheap mineral oil,
sprayed by means of superheated steam or compressed air, by which I can obtain
a white heat when necessary although in the destruction of this refuse it is
unnecessary to go so high as that..
The size and form of the destructor is not a matter of the greatest importance

page_text: and will vary according to the amount of work to be done; but it is essential that
the organic matter be completely removed; I prefer to employ a destructor which
I have specially designed for this purpose.
The destructor consists of a square or other suitably shaped chamber, provided
at the top with a hopper or hoppers and suitable feed-regulating apparatus and
made with two transverse vertical division walls at right angles to one another
dividing the said chamber into four compartments both walls being made with a
number of holes or perforations. Each compartment is also provided with three
perforated arched divisions one above the other, the perforations of one arched
division being so placed as not to be situated immediately above those of the
division next below it,
At the sides bottom and top of this chamber I provide injecting pipes for
supplying sprays of common petroleum or other cheap oil thereto, by means of a
jet of superheated steam or air under pressure such pipes being passed into the
destructor through larger pipes through which air can enter into the chamber to
promote combustion; and I place one or more of these injecting pipes at or near
the opening into the flue of the destructor in order to ensure the complete
combustion of any deleterious gases before the flue is reached.
It will be seen that when the sprays of oil are ignited the interior of the
chamber will be almost filled with flames and the division walls may become white
hot. The sludge, entering at the top, dropping from one arch to another and
falling through the flames, is thus perfectly freed from all organic matter and
finally falls into a compartment at the bottom of the destructor from whence it can
be raked or otherwise removed as it accumulates.
In connection with my process though not a part of my invention I use (in
preference to the ordinary rectangular tanks generally employed) settling tanks of
cylindrical shape with conical bottoms in which the sludge deposit takes place on
the same principle as those used for the separation of the lime and magnesia thrown
down from the brine of the Solvay process of alkali manufacture, or the tanks in
use at Dortmund, for sewage purification, both of which have been described and
published in this country.
Dated this 30th day of Mar 1809
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Tanks or Vessels and Apparatus used in the
Purification of Sewage and other Foul Waters by Precipitation,
and in the Treatment of the Sludge obtained in such Process.
I HAMOR LOCKWOOD of 7 Chapel Walks Manchester in the County of
Lancaster, Manufacturing Chemist, 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 :-
3
In the purification of sewage and other foul waters by means of chemical
substances, a precipitate is produced which has hitherto been allowed to settle at
the bottom of the tanks, and then let off, and either carried out to sea when that is 4
practicable, or pressed by means of specially constructed presses, which latter
process is costly, and the resulting cake in all cases of low manurial value,
and in the case of the use of any form of iron as a precipitate of no value
whatever.
As thrown down, and settled in open tanks ready for running off, this precipitate 5
holds about ninety per cent. of water.

page_text: My improvements consist principally in pumping or allowing this sludge to run
into closed tanks or vessels of special construction as hereinafter described, whereby
it can be subjected to the action of a vacuum which removes a great part of this
ninety per cent. of water, and gives the remainings ludge a consistency sufficient to
stand the second part of the process (which is conducted in the same vessel) sub-
jecting it to an air pressure (by means of an air pump) of about one hundred
pounds to the square inch, or such other pressure as may be consistent with the
strength of the vessel, or may be most economical in the circumstances of each
particular case.
From this vessel the hard-pressed sludge is conveyed to a destructor or cremator,
fed by means of fluted rollers or otherwise, the sludge travelling through the
flame in the destructor or cremator by which means the organic matter therein
is totally destroyed and rendered innocuous whilst the mineral matter remaining
may be used for concreting mixing with mortar or filling up waste land, or
for any other suitable purpose, without the slightest danger to the health of
the inhabitants of the neighbourhood and without having caused any nuisance in
the process.
The manner of carrying out my invention into practical effect will be readily
understood on reference to the two sheets of drawings hereunto annexed and the
following explanation thereof.
On Sheet 1 of the drawings Fig. 1 is a longitudinal section and Fig. 2 a partial
end view and transverse section of the tank or vessel in which the sewage or other
foul water is treated in the first place to remove the greater quantity of the water
therefrom.
On Sheet 2 of the drawings Fig. 3 is a longitudinal section. Fig. 4 an end view
Fig. 5 a plan or horizontal section through about A-B in Fig. 3 and Fig. 6 a
transverse section of the destructor or cremator used in the second or final part of
the process. Fig. 7 is a detached view hereinafter mentioned.
Referring to Sheet 1 of the drawings a is a strong iron cylinder or vessel, (the
size and strength of which will depend on the amount of sludge to be treated and
the pressure required) and inside this I place a perforated iron cylinder > open at
the top and of smaller diameter, to the inner surface of which I attach a strong
canvas lining acting as a filter.
The flanges at the ends of this double cylinder are faced and fitted with plates c
covering the ends, of such a strength as will withstand the pressure to be used.
The sludge is conveyed from the open tanks by means of a pipe d into the inner
or perforated cylinder b, and a vacuum is created by means of an ejector (or
equivalent device) connected to the pipe e in the space between the two cylinders,
and continued till no more water can be extracted. When this occurs a further
quantity of sludge is run in and the vacuum re-applied until the inner cylinder b
is full of sludge with so much water removed as can be effected by the power of
the vacuum.
The air pump is then applied by the pipe f and worked so as to drive the
water out by the ejector pipe e or other convenient aperture until no more water
can be extracted.
It will be understood that the pipes d, e, f, and g are each provided with a
suitable stop tap.
When no more water can be extracted by pressure the sludge may be removed
by the manhole h or if too solid for this one of the end plates c may be removed
and the sludge dug out. The vessel can then be washed out by admitting
water through the pipe g and the end replaced, when it is ready for use for a
further batch.
The sludge removed from the vessel is taken to a destructor or cremator, &
convenient and economical fuel for which I find to be crude creosote oil, or
common petroleum, or other cheap mineral oil, sprayed by means of superheated
steam or compressed air, by which I can obtain a white heat when necessary

page_text: although in the destruction of this refuse it is unnecessary to use so high a
temperature.
The size and form of the destructor or cremator is not a matter of the greatest
importance and will vary according to the amount of work to be done, but it is
.essential that the organic matter be completely removed.
I prefer to employ the destructor or cremator which I have specially designed
for this purpose, and which is illustrated on Sheet of the annexed drawings.
The destructor consists of a square or other suitably shaped chamber i provided
at the top with a hopper or hoppers k and suitable feed regulating apparatus, such
for example as the sliding doors and levers m Fig. 6.
The chamber is provided with two vertical division walls at right angles to
one another dividing the said chamber into four compartments both walls being
made with a number of holes or perforations. Each compartment is also provided
with two perforated arched divisions one above the other, the perforations of one
arched division being preferably so placed as not to be situated immediately above
those of the division next below it.
At the sides and one end of these chambers provide injecting pipes p for
supplying sprays of creosote, common petroleum, or other inexpensive oil thereto,
by means of a jet of superheated steam or air under pressure, such pipes p being
passed into the destructor through openings through which air can enter into the
chambers to promote combustion, and I may place one or more of these injecting
pipes at or near the opening into the flues of the destructor, in order to ensure
the complete combustion of any deleterious gases before the flue is reached.
Any convenient form of spray-producer may be employed to distribute the oil
but I find a very suitable and convenient form to be that illustrated in section on
a larger scale at Fig. 7 in which t is the steam admission pipe and u the pipe
leading to the oil cistern or reservoir.
It will be seen that when the sprays of oil are ignited the interior of the
chambers will be almost filled with flames and the division walls may become
white hot.
The sludge entering at the top through the hoppers k dropping from one
perforated arch o to another and falling through the Hame is thus perfectly freed
from all organic matter and finally falls into the compartment at the bottom of
the destructor whence it can be raked or otherwise removed through the doors w
as it accumulates.
In connection with my improved process (though not a part of my invention) I
use, in preference to the ordinary rectangular tanks generally employed, settling
tanks of cylindrical shape with conical bottoms in which the sludge deposit takes
place on the same principle as those used for the separation of the lime and
magnesia thrown down from the brine in the "Solvay" process of alkali manu-
facture or the tanks in use at Dortmund for sewage purification both of which have
been described and published in this country.
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 1
claim is :-
:
First The particular construction and use of the double cylindrical tanks or
vessels in which the precipitated sludge is treated first by means of vacuum and
secondly by means of compressed air for expressing the water therefrom substantially
as hereinbefore described and illustrated.
Secondly: The particular construction and use of the destructor or cremator
using creosote or other hydrocarbon oil as fuel for destroying and rendering
innocuous all organic matters which may be contained in the sludge without
nuisance or danger to health substantially as hereinbefore described and illustrated,
and
:
Thirdly I claim the treatment of the sludge obtained in the purification of

page_text: sewage and other foul waters by precipitation, by submitting the same in a closed
vessel or vessels first to a vacuum and then to compressed air to express the water
therefrom, and afterwards by passing the more or less solid product through a
destructor or cremator to destroy all organic matters substantially as hereinbefore
described.
Dated this 27th day of February 1802
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.