MENTS IN MACHINERY: OR APPARATUS FOR PREPARING PULP SUITABLE FOR THE MANUFACTURE OF, PAPER
Year: 1856

page_text: by the Act.)
PROVISIONAL SPECIFICATION left by Charles Sidney Johns at the Office
of the Commissioners. of Patents, with his Petition, on the 13th October
1856.
I, CHARLES SIDNEY JOHNS, of Barnards Inn, Holborn, in the County.of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN MACHINERY: OR APPARATUS FOR PREPARING PULP SUITABLE FOR THE
MANUFACTURE OF, PAPER," to be as follows:-
. My Invention consists of improvements in machinery or apparatus. for
preparing pulp. One arrangement of the apparatus consists of a double iron
vessel, fitted one within the other, and sufficiently strong to withstand: con-
siderable pressure. Within the inner vessel is fitted an agitator, and it is pro-
vided with apertures for the purposes of filling and discharging the contents.
The outer. vessel does not communicate with the inner one, but serves as a
steam jacket to, confine the steam by which the inner vessel is heated. High-
pressure steam is conveyed into the space between the vessels by an induction
pipe connected with a boiler, and is exhausted by means of a pump. The
inner vessel is fitted with an air vessel pressure guage thermometer, safety
valve, and a valve or tap by which a portion of the contents may be with-
drawn; straw or other suitable vegetable material is placed within the inner
vessel, which is then filled up with caustic alkaline liquor, and the openings.
securely fastened. Steam is allowed to flow between the vessels, and is caused

page_text: to circulate by means of the pump; the steam as it circulates round the vessel
imparts its heat thereto, and the alkaline liquor, being under pressure, continues
to absorb heat until the desired temperature is attained, which is regulated by
the load on the safety valve. The inner vessel is kept filled by a hydraulic or
ordinary pump. A portion of the contents may be withdrawn from time to
time to ascertain the progress of the process.
Another arrangement of the apparatus consists of an iron vessel to hold the
straw and alkaline liquor. Within the vessel is fitted a coil of pipe, a portion of
which passes through a furnace, and is fitted at one extremity with a suitable
expansion vessel. The coil is filled with water, and heated to a high tempera-
ture; as the water circulates through the coil the heat is imparted to the
alkaline liquor, which is kept under pressure by similar means to the foregoing,
and the vessel is fitted with like appurtenances....
Another arrangement of the apparatus consists in heating the alkaline liquor
in pipes communicating with the iron vessel. The alkaline liquor is forced into
the vessel and withdrawn therefrom by means of one or more pumps.
Another improvement consists in heating the pipe or pipes which convey the
alkaline liquor to the vessel by means of a bath of metal, or an amalgam of
metals.
I
Another part of my Invention consists of an improved agitator. This is made
with a hollow shaft or axis, from which hollow arms radiate; to these arms are
secured smaller perforated tubes. Upon the shaft is fitted an Archimedean
screw, or a series of curved blades; when put in motion, the screw or blades
lift the vegetable substance, and prevent its accumulating at the bottom of the:
vessel; at the same time, the shaft being in connexion with the alkaline
liquor pipe, the highly-heated fluid is forced through the perforated tubes,
coming in contact with the straw or other material as it is turned over by the
screw or blades.