Improvements in or relating to Vacuum Pans and other Apparatus Heated by Steam Worms.
Year: 1892

page_text: Date of Application, 2nd Sept., 1892
Complete Specification Left, 30th May, 1893-Accepted, 1st July, 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to Vacuum Pans and other Apparatus
Heated by Steam Worms.
We, ALFRED CHAPMAN of 17 York Street, Liverpool, Engineer, and SAMUEL
VICKESS Junior of 54 Falkner Street Liverpool Engineer, do hereby declare the
nature of this invention to be as follows:
In the use of vacuum pans it has been found that the efficiency of the ordinary
worm surface is greater when the worms are short in comparison to their diameter
than when they are longer, and the objects of this invention are to so shorten the
length of each section of worm as to render it as efficient as possible, and also to so
construct it that in case of accident any portion of the worm can be removed from
the pan for repairs without interfering with or removing any other portion.
With these objects we place as many distributing boxes in the vacuum pan as
there are to be worms, and from one side of each of these boxes we carry as many
coils as the nature and size of the worms and pan will admit in a true circle until
they meet the distributing box again to which they are bolted; and we interpose a
dividing plate by means of which the steam admitted on one side of the plate enters
the upper end of each coil, and the condensations from each coil enter the distri-
buting box on the other side of the dividing plate. Thus all the coils receive
steam on one side of the dividing plate from the branch connecting the distributing
box to the steam supply, and all the coils deliver condensations into the distributing
box on the other side of the dividing plate from whence they run away by the
In certain
ordinary tail pipe to their corresponding steam trap or otherwise.
cases the dividing plate need not be used the coils being otherwise fitted as
described.
To facilitate the construction of each coil and its repair when necessary we
divide each coil in the centre into two equal parts when the total diameter of the
coil is not so great as to require its being divided into more than two parts. We
thus avoid having any brazed joints in the coils and render their construction
simpler and their erection easier than it has been heretofore, whilst if they are
required for shipment abroad their packing will cost less and their bulk for freight
be much reduced.
Although specially applicable to vacuum pans, the invention can also be applied
to other apparatus which are heated by steam coils.
Dated this 2nd day of Sentember 1892.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in or relating to Vacuum Pans and other Apparatus
Heated by Steam Worms.
We, ALFRED CHAPMAN of 17 York Street, Liverpool, Engineer, and SAMUEL
VICKESS Junior of 54 Falkner Street, Liverpool, Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
In the use of vacuum pans it has been found that the efficiency of the ordinary
worm surface is greater when the worms are short in comparison with their diameter
than when they are longer, and the objects of this invention are to so shorten the
length of each section of worm as to render it as efficient as possible, and also to so

page_text: construct it that in case of accident any portion of the worm can be removed from
the pan for repairs without interfering with or removing any other portion.
With these objects we place as many distributing boxes or steam chests in the
vacuum pan as there are to be worms, and from one side of each of these boxes or
chests we carry as many coils as the nature and size of the worms and pan will
admit in a true circle until they meet the distributing box again to which they are
bolted and we interpose a dividing plate by means of which the steam admitted
on one side of the plate enters the upper end of each coil, and the condensations
from each coil enter the distributing box on the other side of the dividing plate.
Thus all the coils receive steam on one side of the dividing plate from the branch
connecting the distributing box to the steam supply, and all the coils deliver
condensations into the distributing box on the other side of the dividing plate from
whence they run away by the ordinary tail pipe to their corresponding steam trap
or otherwise. In certain cases the dividing plate need not be used the coils being
otherwise fitted as described.
To facilitate the construction of each coil and its repair when necessary we
divide each coil into two or more pieces of equal or unequal lengths as may be
found convenient according to the greater or less diameter of the coil or other
circumstances.
We thus avoid having any brazed joints in the coils and render
their construction simpler and their erection easier than it has been heretofore,
whilst if they are required for shipment abroad their packing will cost less and
their bulk for freight be much reduced.
Although specially applicable to vacuum pans, the invention can also be applied
to other apparatus which are heated by steam coils.
The accompanying drawings will enable our invention to be clearly understood.
In these drawings
Figure 1 is a section on the line a-x of Figure 2 and Figure 2 a plan showing
a vacuum pan constructed according to our invention in its preferred form.
Figure 3 is a section of one of the distributing boxes or steam chests on the
line y-y of Figure 1.
.
The pan is shown as provided with three worms but the number will vary
according to the size of the pan and the particular purpose for which it is intended.
a a represents the lower portion of the pan. b are three distributing boxes
or steam chests one for each worm; these boxes are supplied separately with steam
by tlie inlet pipes c c c. Each worm is shown as composed of five coils d' d² d³ d' d³
which are not continuous but are each connected at their upper end to one side of
the corresponding box above a dividing plate e in this. box and after passing
round the pan in a true circle are connected at their lower end to the other side of
the same box below the dividing plate e. It will be readily understood that
the steam admitted by the pipe c to the respective distributing boxes babove the
dividing plates e will enter the upper end of each coil d' &c. and that the
condensations from each coil will pass into the distributing boxes below the dividing
plates. The condensations pass out by the tail pipes to their corresponding
steam traps or otherwise. The coils are shown as each divided into two equal
pieces connected together at g g (Figure 2). The number of pieces making up
each coil and the relative lengths of these pieces should be regulated according to
the diameter of the coil and other circumstances. are stays or frames which
in combination with the distributing boxes bb serve to retain the worms in position.
Instead of arranging the dividing plates e which separate the upper ends of all
the coils of each worm from the lower ends of the same coils as in Figures 1, 2 and 3
the dividing plates may be vertical as shown in Figure 4.
Or the dividing plates may be dispensed with as illustrated in Figure 5 in which
case the steam would be free to enter each coil at both ends but as the coil has an
inclination to one end the condensations will run to that end and falling into the
box or chest pass to the bottom of same and escape by the tail pipe f
Figure 6 is a fractional view representing in plan another way of staying or
rétaining the worms in position. In this case the two parts of each coil d d &c.

page_text: instead of being connected directly to each other as in Figure 2 are connected to
the opposite sides of a plate i fixed to the wall of the pan a and supported at its
inner end by a leg at k. The plate i has apertures corresponding with the bore of
the coils d² &c.
In addition to facilitating the erection and repair of the worms or coils our
invention has the great advantage of increasing the efficiency of the heating
surface because of the use of short coils well drained, and also of increasing the
efficiency of the vacuum pan as a whole as there is more space between the coils
for the boiling mass to move through because from the increased efficiency of
the coils in proportion to their surface; fewer coils are required to do a given
amount of work and more space can therefore be allowed between them.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a vacuum pan or other steam worm heated apparatus one or more worms
each composed of a number of separate coils connected at their extremities to the
same distributing box or steam chest there being a separate distributing box for
each worm, substantially as herein before described.
2. The construction of vacuum pans and other steam worm heated apparatus,
substantially as hereinbefore described and represented in the accompanying
drawings.
ם
11
CM 1902
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.