IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD AND IN APPARATUS THEREFOR, PART OF WHICH INVENTION RELATES TO THE PRODUCTION OF LIME
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
9th June 1874.-A communication from abroad by Asa Park
Meylert, of New Britain, Connecticut, United States of America.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
WHITE LEAD AND IN APPARATUS THEREFOR, PART OF WHICH INVENTION RELATES
TO THE PRODUCTION OF LIME," a communication, to be as follows:-
This Invention relates to further improvements in the manufacture of
white lead described in the Specification of former Letters Patent dated
January 18th, A.D. 1873, No. 213, and is designed to afford greater
economy and efficiency than can be attained by the use of the apparatus
described in the said former Specification.
The first improvement relates to a combination of white lead manu-
facture with the manufacture of lime. This combination is effected by
crecting a hood or cover of any suitable form, and by any proper method
upon or over a kiln or kilns used in lime burning, for the purpose of

page_text: collecting the carbonic acid gas which would otherwise escape into the
air, and by attaching a suitable pipe or pipes to the hood or hoods which
shall connect the same with one or more corroding rooms, in which
metallic lead is placed for corrosion, said pipe or pipes to be so arranged
that the processes of lime burning and of lead corroding may be carried
forward simultaneously by conveying the carbonic acid gas set free from
the limestone into contact with the metallic lead in connection with
other suitable corroding agents.
The second improvement relates to the construction of corroding
rooms used in the manufacture of white lead. The said rooms may be
of any convenient size and shape, but they should be so constructed that
they may be closed at the top and sides in order to retain the vapours
and gases which may be admitted at any convenient point, but with a
pipe or series of pipes which shall enter or shall communicate with the
rooms at or near the top in such manner that air may be freely conveyed
to the said rooms from without; and to effect this object in the best
manner the air may be forced into the room by means of a suitable air
pump or blower through the pipe or opening above-mentioned; or pre-
ferably the outer terminus of said pipe or pipes is placed at a lower
level than the terminus of the same within the corroding room. The
pipes now used by me for conveying atmospheric air to the corroding
rooms have their internal opening near the top of the room, and their
external opening below the level of the bottom of the room, although I
have used a pipe having its lower and outer terminus at the side of the
room with good advantage. Instead of a pipe the walls of the room may
wholly or in part be made hollow with internal openings at the top, and
external openings at the bottom, which may be closed by suitable
dampers or grates. I find it likewise to be advantageous to use a layer of
spent tan bark or other suitable porous material resting upon a false
bottom placed below the lead in the corroding room. The steam either
direct or exhaust is made to enter below this layer of tan bark, which is
kept moist above by any suitable means. Thus the warm tan bark gives
off a vapor of low temperature which rises into the corroding room. The
surplus steam which has been forced into the space below the layer of
tan bark above described is conveyed by a suitable conducting pipe into
the corroding room, discharging at a point near the top of the room.
Should the steam enter the room at the latter point too dry, a spray or
jet of water is admitted into contact with the steam within the said

page_text: steam conducting pipe just before it discharges into the room. Α'
greater volumn of watery vapor if required is caused to enter the
corroding room, by forcing air also into the bottom space below the
layer of spent tan bark. Should the mass of lead within the corroding
room become very dry, a jet or spray of water may be thrown into the
air conduction pipe before-mentioned at a point near its entrance to the
corroding room. The surplus and waste gases and vapors may be per-
mitted to discharge from the corroding room at any convenient point,
preferably by a pipe having its opening from the room near the top, and
its point of discharge at a lower level.
The third improvement relates to the filling of the corroding rooms
with metallic lead for the purpose of corrosion. I use for this purpose
the following apparatus :—Movable floors, shelves, or tiers placed within
the corroding room are covered with metallic lead cast in the form of
buckles, crates, or other suitable pieces. These are conveyed by suitable
belts passing over driving pulleys from the casting plates or moulds to a
point above the rooms, whence they are permitted to drop and to slide
by a suitable chute to any portion of a corroding room as desired. By
these means the corroding room is rapidly and economically filled with
very little hand labor. A conveyor belt may be passed over driving
pulleys above the partition which is made to separate any number of
adjacent rooms, the said belt passing in the direction of the partition
that is above and along the line of the partition by simply increasing or
diminishing the length of the belt; and by means of a series of pulleys it
may be made to deliver the lead above any of the corroding rooms of the
series, and a chute may be made to deliver the buckles or pieces of lead
from this conveyor to any portion of either room of the series.
The fourth improvement relates to an improved apparatus for
vaporizing acetic acid. This apparatus consists of a large stand pipe
containing, coke or other porous material. Carbonic acid gas is freely
admitted or forced into said stand pipe at or near the bottom of the
same, and after passing around, over, and through the interstices of the
coke is conveyed to the corroding room from a point at or near the top
of said stand pipe. Acetic acid is simultaneously conveyed in the said
stand pipe at or near the top, and is permitted to percolate over and
among the pieces of coke or other porous material, being thereby
brought into intimate contact with the carbonic acid gas. Any surplus
acetic acid may be collected and conveyed to a suitable vessel placed

page_text: below the said stand pipe, and the acid may be reconveyed within the
said pipe at or near the top by a pump or by other suitable means.
The fifth improvement relates to an improved apparatus for purifying
carbonic acid gas. This apparatus consists of a large stand pipe through
which impure carbonic acid gas is passed simultaneously with suitable
purifying material. The said purifying material may be passed through
the stand pipe in the form of a liquid spray, or it may be passed over
coke or other suitable porous material which may be placed within the
said stand pipe, and the carbonic acid gas may be made to pass through
the interstices of the coke or other porous material, and thus be brought 1
in contract with the purifying material. Any surplus portion of the
purifying material may be collected and conveyed to a suitable vessel
placed below said stand pipe, and the same may be reconveyed within
said stand pipe by means of a pump or by any other suitable means.
In the processes and apparatus herein described I do not limit myself
to the use of carbonic acid gas derived from the manufacture of lime as
hercin-before described, as they are equally applicable when the carbonic
acid gas is derived from any other source whatever.