IMPROVEMENTS IN THE TREATMENT OR PURIFICATION OF THE WASTE LIQUIDS DISCHARGED FROM PAPER MILLS AND OTHER WORKS, AS WELL AS THE SEWAGE OF TOWNS, AND IN THE MODES AND MEANS EMPLOYED THEREFOR
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Thomas Stevens at the Office
of the Commissioners of Patents, with his Petition, on the 11th
August 1875.
I, THOMAS STEVENS, at present residing at May Villa, Chirnside, in
the County of Berwick, North Britain, Civil Engineer, do hereby declare
the nature of the said Invention for " IMPROVEMENTS IN THE TREATMENT
OR PURIFICATION OF THE WASTE LIQUIDS DISCHARGED FROM PAPER MILLS AND
OTHER WORKS, AS WELL AS THE SEWAGE OF TOWNS, AND IN THE MODES AND
MEANS EMPLOYED THEREFOR," to be as follows :-
This Invention relates to the purification and defecation of the
discharge water or liquids from paper mills and other works, as well as
the sewage of towns, in order to separate the organic and inorganic
matters held in suspension before the discharge water or sewage reaches
or pollutes the rivers.
And the nature and novelty of the Invention consist in using a
purifying agent or compound of a non-injurious nature, composed of
sulphate of lime and chloride of sodium commingled or mixed together
in the dry state in about equal proportions, which rapidly defecates and

page_text: precipitates the matters held in suspension in the discharge liquid or
sewage, leaving an effluent water.
The compound or agent is placed in a contiguous cistern or hopper,
and is allowed to fall regularly in a continuous stream through suitable
connections or tubes into the pipe (or pipes), in which the discharge
water is conducted from the mill or other work to a settling tank
(or tanks); the proportion admited being about two gallons of the
agent or compound for every thousand gallons of discharge liquid, and as
they flow on towards the settling tank they become thoroughly mixed
and incorporated, and at the outflow end of the pipe a proportion of the
common agent, "milk of lime," of about two gallons to every thousand
gallons of discharge water is admitted, the whole passing through a
small wheel in the pipe (which may actuate the stirrer or agitator in
the lime cistern above) thoroughly amalgamating the several ingredients
with the water as it flows into the first compartment of the tank.
The tanks are divided into three compartments by walls or divisions
with sluices in them, and into the first compartment about ths (seven
eighths) of the matter held in suspension in the water is deposited, and
as the water rises to the top of the first division wall, it flows over into
the second compartment in a thin stream, and therein deposits the
remaining matter held in suspension, and the water having next filled
this compartment flows over the second division wall into the third
compartment which it fills to the height of several feet, and then flows
down through a vertical filter into a small chamber, and thence through
pipes to the river.
The precipitated matter is pumped out at intervals by a chain pump
and engine into another tank, and therein drained of any superfluous
water remaining; and the precipitate or sludge is then mixed with a
sufficient or desired quantity of the sulphate of lime to convert it into a
valuable manure.
The foregoing process is quite sufficient for the purification of the
usual discharge water from the washing engines of paper mills, but to
treat and utilize all the water passing from the mill, such as the
coolings," the "lees," and the water from the "
paper machine,"
<C
which hold chloride of lime in solution, it is desirable to add a small
proportion of sulphuric acid to the before mentioned purifying agent,
but any poison it may contain after passing through the filter is
destroyed by the common filtering medium.

page_text: The foregoing process as well as the modes and means employed for
carrying it out in practice, are equally adapted for treating the sewage
of cities and towns, and the precipitate or sedimentary matter is converted
into a valuable manure, the effluent water from the sewage being well
adapted for irrigating land, but in treating sewage the proportions of the
purifying or defecating compound relatively with the nature or fluidity
of the sewage, may in many cases have to be varied to some extent.