IMPROVEMENTS IN THE CONSTRUCTION OF BOILERS OR OTHER VESSELS USED IN THE CONVERSION OF WOODY OR OTHER FIBRES INTO PULP FOR THE MANUFACTURE OF PAPER OR OTHER ARTICLES PREPARED FROM PULPED FIBRES
Year: 1885

page_text: I ALEXANDER MCDOUGALL Gentleman Beech Grove Penrith do hereby declare
the nature of my invention for IMPROVEMENTS IN THE CONSTRUCTION OF BOILERS
OR OTHER VESSELS USED IN THE CONVERSION OF WOODY OR OTHER FIBRES INTO
PULP FOR THE MANUFACTURE OF PAPER OR OTHER ARTICLES PREPARED FROM
PULPED FIBRES to be as follows:-
Boilers or other vessels used in the conversion of woody or other fibres into pulp.
for the manufacture of paper, or other articles, by the acid process, are usually
constructed of iron or steel and are lined with lead to protect the iron or steel from
the action of the acid, and the pulp from the disoloration which might be caused
by the solution of the iron or steel.
Great inconveniences are experienced in the use of such boilers or vessels in con-
sequence of the unequal expansion and contraction of the two metals on their being
alternately heated by the steam and cooled on the discharge of each successive batch
of pulp.
My Improvements consist in constructing these boilers or vessels with an inter-
mediate packing of felt or other compressible and elastic material, so that when
the interior leaden vessel is heated and thereby enlarged & pressed outwards by
the steam, the compressible and elastic packing yields to the pressure & expansion
Also on the cooling of the vessels, the packing responds to the contraction and
approximates to its original bulk and pressure between the two vessels and so
prevents the rupture or tearing of the lead and its consequent leakage and other
inconveniences.
Another portion of my Invention consists in the construction of the outer iron
or steel vessel in flanged sections which are fitted to incase the interior leaden
vessel, with a space between the two vessels into which the compressible and elastic
materials are packed. In the construction of these vessels the iron or steel flanged
sections are placed onto the leaden vessel and packed with the compressible and
elastic lining in succession As each section is packed it is screwed close up to the
adjoining section by the screw bolts fitted into corresponding holes in the flanges
of the contiguous section until completed.

page_text: for the Manufacture of Paper or other Articles Prepared from
Pulped Fibres.
ALEXANDER MCDOUGALL Gentleman Beech Grove Penrith I do hereby declare
the nature of my invention for IMPROVEMENTS IN THE CONSTRUCTION OF BOILERS
OR OTHER VESSELS USED IN THE CONVERSION OF WOODY OR OTHER FIBRES INTO
PULP FOR THE MANUFACTURE OF PAPER OR OTHER ARTICLES PREPARED FROM
PULPED FIBRES, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
Boilers or other vessels used in the conversion of woody or other fibres into pulp
for the manufacture of paper, or other articles, by the acid process, are usually con-
structed of iron or steel, and are lined with lead to protect the iron or steel from
the action of the acid, and the pulp from the discoloration which might be caused
by the solution of the iron or steel.
Great inconveniences are experienced in the use of such boilers or vessels in con-
sequence of the unequal expansion and contraction of the two metals on their being
alternately heated by the steam, and cooled on the discharge of each successive batch
of pulp..
My Improvements consist in constructing these boilers or vessels with an inter-
mediate packing of felt or other compressible and elastic material, so that when the
interior leaden vessel is heated and thereby enlarged & pressed outwards by the
steam the compressible and elastic packing yields to the pressure & expansion.
Also in the cooling of the vessels the packing responds to the contraction and
approximates to its original bulk & pressure between the two vessels and so
prevents the rupture or tearing of the lead and consequent leakage and other
inconveniences.
Another portion of my Invention is the construction of the outer iron or steel
vessel in flanged sections which are fitted to incase the interior leaden vessel with
a space between the two vessels into which the compressible & elastic materials are
packed.
In the construction of these vessels the iron or steel flanged sections are placed
onto the leaden vessel and packed with the compressible and elastic lining in
succession As each section is packed it is screwed close up to the adjoining
section by the screw bolts fitted into corresponding holes in the flanges of the
contiguous section until completed.
This method of construction secures economy by the retention of the heat which
is effected by the packing between the two vessels. Its chief advantage is the
preservation of the interior leaden vessel from the unequal strain or tear by the
yielding of the compressible and elastic packing on the introduction of steam, and
its approximation to its normal bulk and pressure on the lowering of the temperaturę
when the contents of the vessel are discharged.

page_text: The compressible and elastic materials which I employ to pack the space between
the leaden and the iron or steel vessels are caoutchouc felt, flocks, coir cork, asbestos
or other similar compressible and elastic materials which may not be injured by
the heat of the steam injected into the interior vessel.
These compressible and elastic materials may be used either mixed in convenient
proportions or they may be used one or other of them alone.
In vessels of the usual size I prefer a space of about two inches between the
vessels into which the packing is filled. The flanged sections of which the outer
vessel is formed I prefer to have about fifteen inches deep. I do not confine myself
to these dimensions of space or depth, but give them as suitable although there may
be cases in which other dimensions may be preferred.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim are
I. The use of compressible & elastic packing such as caoutchouc folt, flocks cork
asbestos or other similar compressible and elastic materials either together or
separately between the iron or steel and the leaden vessels or boilers used for the
conversion of fibres into pulp.
II. The construction of the outer iron or steel vessels in Banged sections to be
drawn together and fixed in position over the intermediate packing, by screw bolts
or other suitable means.