IMPROVEMENTS IN MASH TUNS, AND IN APPARATUS TO BE EMPLOYED THEREWITH, WHICH APPARATUS IS ALSO APPLICABLE TO THE HEATING AND KEEPING UP OF A CONTINUOUS CIRCULATION OF LIQUIDS IN ANY VESSEL TO WHICH IT MAY BE CONNECTED
Year: 1857

page_text: application for Letters Patent was not given within the time prescribed
by the Act.)
PROVISIONAL SPECIFICATION left by John Grist at tho Office of tho
Commissioners of Patents, with his Petition, on the 20th February
1857.
. I, JOHN GRIST, of Islington, in the County of Middlesex, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN MASH
TUNS, AND IN APPARATUS TO BE EMPLOYED THEREWITH, WHICH APPARATUS IS ALSO
APPLICABLE TO THE HEATING AND KEEPING UP OF A CONTINUOUS CIRCULATION OF
LIQUIDS IN ANY VESSEL TO WHICH IT MAY BE CONNECTED," to be as follows:-
My improvements in mash tuns consist, first, in dividing the interior thereof
by perforated vessels or chambers, whereby the grains can be readily taken
from the tun, a crane or other suitable apparatus being employed to draw up
each chamber out of the tun. For the sake of discharging the grains from the
chambers, I fit them with a hinged or sliding bottom or side; and, second, in
fitting the tuns with the heating and circulating apparatus, to bo presently
described.
My apparatus for heating and keeping up a continuous circulation of liquids
in mash tuns and other vessels consists of a cylinder fitted with tubes; the
liquid way through the tubes is connected by a pipe leading from each end of
the cylinder to the upper part of the mash tun or vessel just below the level of
the liquid contained therein; a stop-cock is fitted to the upper part of each
pipe outside the tun or vessel; branch pipes, also fitted with stop-cocks, lead

page_text: into the pipes, and these branch pipes connect the liquid contents of the tun or
vessel just below tho perforated false bottom, when such false bottom is
employed, or the contents of the tun close to the bottom thereof, with the pipes
leading into the tubes in the cylinder. There is a clear passage for liquid
through the tubes fitted in the cylinder. It is essential for the proper working
of the apparatus that the cylinder, or rather the tubes forming. the liquid way
through the same, should be placed at an angle with a horizontal line. Steam
or hot air is admitted into the cylinder, and a valvo for the escape of water
from condensed steam or for air beyond a certain pressure is fitted thereto, to
allow of the water of condensation or the air being discharged outside of
the cylinder. The operation is as follows:-Supposing the mash tun or vessel
to be charged, communication with the top of the tun on one side is shut off by
the stop-cock on the upper part of one of the pipes leading to the tubes in the
cylinder, and the cock in the branch pipo from the same side of the tun is
opened. On the contrary, the cock on the opposite branch pipe is closed, and
that on the opposito pipe loading into the top of the tun is opened. Steam
being now admitted into the cylindor will raise the temperature of the liquid
contents of the tubes fitted therein, which, becoming of loss specific gravity than
the colder contents of the tun, will ascend through the open communication
into the top of the tun; the contents of the tun will also flow out through the
branch pipe communicating from the bottom of the tun with the opposite end
of the cylinder to that from which the liquid ascended, and so on continuously
as long as the temperaturo of the steam is kept in excess of that of the
contents of the tun. By reversing the cocks the liquid may be drawn from
the top, passed through the liquid way in the cylinder, and made to enter the
bottom of the tun; or, by setting the cocks to suit the circulation desired, the
liquid may be drawn from the top or bottom of the tun on one side, passed
through the liquid way in the cylinder, and delivered into the top or bottom of
the tun on the opposite side. The heating and circulating effects are in every
case due to the increased temperature generated in the cylinder by steam, hot
air, or heated gases admitted or forced into it.