AN IMPROVED PROCESS OF DEODERIZING, DISINFECTING, PRECIPITATING, DRYING AND PULVERIZING THE SOLID PORTIONS OF SEWAGE TO RENDER IT A MARKETABLE MANURE
Year: 1884

page_text: I WILLIAM ASTROP of No 116 Roman road Barnsbury Islington in the County of
Middlesex Chemist do hereby declare the nature of my Invention for AN IMPROVED
PROCESS OF DEODERIZING, DISINFECTING, PRECIPITATING, DRYING AND PULVERIZING
THE SOLID PORTIONS OF SEWAGE TO RENDER IT A MARKETABLE MANURE, to be as
follows:-
The object of this invention is to deal with sewage and other polluted matters to
render them innocuous and to convert the solid portions into a valuable manure for
agricultural purposes by an economical process.
In carrying out my invention I proceed as follows-the sewage is collected direct
from the Sewers in a suitable receptacle and is there mixed with the precipitant A
which I use in a milky condition in quantities according to the amount of sewage
to be treated in the manner described below.
The precipitant A is a combination of calcium Hydrate, Carbonato of Alumina,
Sulphate of Soda or Potassim and finely sifted cinder ashes, together or separate,
For the more economical method of manufacturing the same I take of pulverized
carbonate of lime (common chalk) a sufficient quantity in a suitable vessel and will
I then take an
macerate it with water to make it about the consistency of cream.
equal quantity of a saturated solution of sulphate alumina or any of the potassæ,
soda or ammonia alums and will mix them together by which means the calcium is
deprived of its carbonic acid gas which is transferred to the alumina forming
carbonate of Alumina leaving sulphate of soda or potassa in solution, the whole is
then mixed with the sewage in the first receptacle-this will disinfect and deodirize
the offensive matters at once when sufficiently agitated it is then run off or pumped
into settling tank N° 2. where all fecal and other impurities will be thoroughly
precipated into a well or lower end of tank-The effluent water is then conducted
into a series of filtering beds composed of coke or charcoal chalk and sand the
effect of this will be to neutralize any excess of chemical that may be used in the
precipitant or that may come down the sewers from chemical or other works-they
will also absorb any noxious gasses and arrest any suspended matters that may
not have been thoroughly precipated-when the effluent water is run from these

page_text: filters it will, in most cases, be practically pure to turn into a river but it may be
advisable to run it into a third tank and then into the river-In large sewage
works these tanks filtering beds & should be used in series although there is no
reasonable limit to the size so long as the capacity is equal to the supply-These
tanks should work continuous instead of drawing off the top water to get at the
sludge or deposit-I use a syphon which dips into a well or the lower end of the
tank which will effectually separate the deposit or a drain may be used fitted with
proper valves or sluice doors-The sludge or deposit is then conveyed by any
suitable means to the drying arrangement as follows-viz: a travelling wire gauze
or felt or cloth, or both, as the case may be, of suitable thickness to prevent the
solid matter from percolating through-To effect the travelling process I fit on a
frame a certain number of carrying rollers which cause the gauze or felt to run over
a vacuum box for the purpose of exhausting the water by atmospheric pressure the
solid then passes through a pair of couch rolls at the end of the machine which will
press out most of the remaining water reducing the solid to a thick pasty condition
which then passes into a rotary cage continuously for the purpose of being
thoroughly dried and pulverized-the material as it is dried is sifted through the
wire gauze on the periphry of the cage or it may be emptied at the extreme end of
the cage or drum, or both, ready to be collected and bagged away. The drying
cage should be placed in a covered chamber with moveable shutters for the purpose
of watching the process, emptying &c-To further facilitate the rapid drying
I cause a blast of air to be driven through the chamber and cage by any well
known means-The air may be at the ordinary temperature of the atmosphere
or it may be warmed by any suitable means, such as steam pipes, or a flue, run
through the chamber, but the temperature should not exceed 100 Fhr.
Dated the 2nd day of September 1884.

page_text: An Improved Process of Deodorizing, Disinfecting, Precipitating,
Drying, and Pulverizing the Solid Portions of Sewage to
I, WILLIAM ASTROP, of 58 Vicarage Road, Park Lane, Tottenham, in the
County of Middlesex, Chemist, do hereby declare the nature of my said Invention
for "AN IMPROVED PROCESS OF DEODORIZING, DISINFECTING, PRECIPITATING,
DRYING AND PULVERIZING THE SOLID PORTIONS OF SEWAGE TO RENDER IT A
MARKETABLE MANURE," and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The object of this invention is to deal with sewage, and other polluted matters,
to render them innoxious, and to convert the solid portions into a valuable manure
for agricultural purposes by an economical process.
In carrying out my invention I proceed as follows:-The sewage is collected
direct from the sewers, in a suitable receptacle, and is there mixed with the
precipitant, which I use in a milky condition in quantities according to the
amount of sewage to be treated, in the manner described below.
The precipitants A is a combination of calcium, sulphate hydrate, and carbonate
of alumina, sulphate of soda, or potassa, and finely sifted cinder ashes, together or
separate. For the more economical method of manufacturing the same, I take
pulverized carbonate of lime (common chalk) a sufficient quantity in a suitable
vessel, and well macerate it with water, to mako it about the consistence of cream.
I then take an equal quantity of saturated solution of sulphate alumina, or any
of the potassæ soda, or ammonia alums, and well mix them together by which
means the calcium is deprived of its carbonic acid gas, which is transferred to the
alumina, forming carbonate of the same, and sulphate of calcium, leaving sulphate
of soda, or potassa in solution; the whole is then mixed with sowage in the first
receptacle this will disinfect, and deodorise the offensive matters at once. When
sufficiently agitated, it is then run off, or pumped into settling Tank Number 2,
where all fecal, and other impurities will be thoroughly precipitated into a well, or
lower end of tank. The effluent water is then conducted into a series of filtering
beds, composed of coke, charcoal, chalk, and sand,-The effect of this will be to
neutralize any excess of chemicals that may be used in the precipitant, or that may
come down the sewers from chemical, or other works; they will also absorb any
noxious gases and arrest any suspended matters that may not have been thoroughly
precipitated. When the effluent water has run from these filters, it will in most
cases be practically pure to turn into a river, but it may be advisable to run it
into a third tank, and then into the river. In large sewage works, these tanks,
filtering beds &c, should be used in series, although there is no limit to the size, so
long as the capacity is equal to the supply, These tanks should work continuously,
instead of drawing off the top water to get at the sludge. I use a syphon, which
dips into a well, or lower end of the tank, which will effectually separate the
deposit, or a drain may be used, fitted with proper valves, or sluice doors. The

page_text: .sludge, or deposit is then conveyed by any suitable means to the drying arrange-
ment as follows, viz-An endless travelling wire gauze, or felt, or cloth or both as
the case may be, of suitable thickness, to prevent the solid matters from percolating
through. To effect the travelling process I fit on a frame a certain number of
carrying rollers, which cause the gauze or felt to run over a vacuum box for the
purpose of exbausting the water by atmospheric pressure, the solid then passes
through a pair of couch rolls at the end of the machine, which will press out most
of the remaining water, and reduce the solid to a cake or sheet, it then passes into
a rotary cage continuously for the purpose of being thoroughly dried, and pul-
verized; the material as it is dried is sifted through the wire gauze on the
periphery of the cage, or it may be emptied at the extreme end of the cage, or
both, ready to be collected, and bagged away. The drying cage should be placed
in a covered chamber with movable shutters for the purpose of watching the
process, emptying &c. To further facilitate the rapid drying, I cause a blast of
air to be driven through the chamber, and cage, by any well known means. The
air may be at the ordinary temperature of the atmosphere, or it may be warmed
by any suitable means, as steam pipes, or a fluc run through the chamber, but
the temperature should not exceed 100° Fahnt.
I find that the quantity of the precipitant to be used will average about 5 cwt
per 100,000 gallons of sewage, but I do not confine myself to that quantity, as the
amount of solid, and suspended matters vary very much at different places, and at
different times during the Twenty four hours.
DESCRIPTION OF DRAWING.
Fig. 1 Longitudinal section showing machinery in a Building with Ground floor,
and Upper floor;-A is a sludge tank for feeding machine by means of pipe X,
this may be effected by being run direct from the precipitating tanks, or may be
pumped, as may be expedient according to situation B. B. B. is an endless travelling
wire gauze, or felt, or both, or any suitable fabric, supported by a stout framework
of wood or metal C. C. C. on which is fitted the required number of carrying
rollers to support the felt, or wire in a horizontal position D. D. D. are vacuum
boxes; one, or more may be filled, the number to be determined by the speed the
inachine is driven, and the quantity of sludge to be treated. The vacuum is to be
maintained by pumps or an exhaustor, or by any well known means.-E E arc
adjustable stretch rollers to keep the wire gauze, and felt taut, and compensate for
the difference of elasticity between the wire, and the felt. F F are two endless
bands, or straps working on pulleys both sides of the machine, to keep the sludge
from running over the sides, these bands press slightly on the gauze, and felt, and
travel with it; said bands or straps should be made of some water-proof material as
caoutchouc &c. &c.-G G are a pair of couch rollers, the lower carrying the wire
gauze, and felt, the upper fitted with adjustable springs or levers, for regulating
the pressure to squeeze out some of the remaining moisture contained in the
pasty mass.-H. is an adjustable stretch roller to support, and carry a loose felt
on the upper couch roller to assist the delivery of the pressed sludge from the
machine. J. J. is a shoot by means of which the pressed sludge is conveyed to
drying cage or cylinder on the floor below, or to any suitable situation. K is a
drying cylinder, or rotary cage, with a wiro gauze, or perforated periphery
supported on stout bearings the rotary motion to be given by any suitable gearing,
to be worked in a closed chamber with an opening to the hot-air chamber, so that
warm, and dry air may pass freely through the said chamber, and cylinder or cage;
to facilitate this, in most cases I use a fan or exhauster, L, which is driven at
suitable speed. M, is the hot-air chamber, which may be heated by any well
known means, as steam, hot water, or furnace &c. N, is an archimedian screw to
deliver the dried sewage as it is sifted through the periphery of the cylinder to the
elevator O, to be put into sacks, or otherwise packed.
The whole to be driven by any well known motive power.

page_text: Having now described the nature of my invention, and how the same may be
brought into effectual working, (although I do not confine myself to all the minor
details) I wish it to be clearly understood, that that which I claim as a novelty in
my invention is as follows
1st The use of calcium-sulphate, and carbonate of alumina together, or mixed
with other ingredients, as a precipitant of the solid, and suspended matter con-
tained in the sewage of towns, rendering them innoxious, and producing a
practically pure effluent water, at the same time retaining much of the manurial
value in the solid matter, which is now being destroyed.
2nd The process herein described for drying, and pulverizing the solid portions
contained in the sewage of towns, by which means it is dried quickly whilst fresh,
before it has had time to sensibly decompose, thereby fixing all the constituents,
which will render it a valuable manure.