Improvements in and in the Manufacture of Coiled Tubular Heating or Cooling Surfaces for Apparatus for Condensing Steam, for Heating or Cooling Fluids, or Evaporating Water.
Year: 1888

page_text: Date of Application, 23rd Oct., 1888
Complete Specification Left, 22nd Aug. 1889-Accepted, 21st Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in and in the Manufacture of Coiled Tubular Heating
or Cooling Surfaces for Apparatus for Condensing Steam, for
Heating or Cooling Fluids, or Evaporating Water.
We, JOHN NEWTON of 79 Mark Lane in the city of London, in the county of
Middlesex, Merchant, and DANIEL ARTHUR QUIGGIN of 28 Chapel Street Liverpool
in the county of Lancaster, Engineer, do hereby declare the nature of this invention
to be as follows:-
In apparatus for condensing steam, for heating or cooling fluids, or evaporating
water, it is usual to provide a chamber into which open the ends of a number of tubes
forming heating or cooling surfaces, the other ends of the tubes opening into a second
chamber similar to the first.
The fluid to or from which heat is to be transmitted enters one chamber, passes
through the tubes and is discharged from the second chamber; the second fluid
from or to which heat is to be transmitted, surrounding the outside of the said tubes,
being contained in a suitable chamber.
The circulation of the fluids may be natural or may be produced by any suitable
means.
According to our present invention we provide tubular heating or cooling surfaces
for such apparatus consisting of one or more coils of metallic tubing whose cross-
section is crescent shaped, the horns of the crescent being rounded; and the outer
When the tube is formed
and inner bounding circles may or may not be concentric.
into a cylindrical spiral coil the horns of the crescent lie on the outside of the coil.
The ends of the tubes may be of circular cross-section to facilitate their attachment
to the tube plates.
We manufacture such coiled tubes from tubes of circular cross-section as
follows:-
We provide a mandrel on which we form a helical groove, the bottom of the
groove being a semicircle of the same or nearly the same diameter as the tube to be
coiled and the depth of the groove being greater than the radius of the semicircle.
The mandrel is carried in a lathe or other suitable machine by which it can be
rotated.
We secure one end of the tube to be coiled to the mandrel, the tube lying in the
groove thereof. We also provide a sliding saddle or frame which can travel parallel
to the axis of the mandrel, and it is driven by suitable gear so as to move over a
distance equal to the pitch of the helical groove while the mandrel makes one revo-
lution. On this sliding saddle or frame we fix a pair of jaws of wood or other
suitable material which grip the tube with an adjustable degree of tightness and
guide the tube into the groove, and keep it in tension while the mandrel is
rotated.
In order to press the tube into the groove and give it the desired section we attach
to the before mentioned sliding saddle or frame a wheel or roller which bears
on the tube at or about the point where the latter is a tangent to the mandrel.
The wheel or roller can be adjusted in a direction radial to the mandrel, and the
central portion of its rim which is semicircular in form presses the tube into the
groove and gives it the desired crescent shaped form of cross-section as the coiling
proceeds. The wheel or roller fits laterally into the groove and has a shoulder at
each side which shoulders bear on the horns of the crescent, and it may have a second
shoulder at each side which abuts against the top of the ridges between the grooves
on the mandrel. A die of suitable configuration may be substituted for the wheel or
roller already described.

page_text: By adjusting the wheel or die radially as the coiling proceeds the form of the tube
section can be varied so that its area may gradually diminish towards one end of
the tube.
Where found necessary to more effectually guide the tube into the groove a guide
to embrace the tube may be fixed to the saddle between the jaws and the mandrel
and as close as possible to the latter.
The mandrel may have more than one helical groove, so that more than one tube
can be operated upon simultaneously, each tube being guided and pressed as
described.
Dated this 22nd day October 1888
SLOAN & LLOYD BARNES,
26, Castle Street, Liverpool, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in and in the Manufacture of Coiled Tubular Heating
or Cooling Surfaces for Apparatus for Condensing Steam, for
Heating or Cooling Fluids, or Evaporating Water.
We, JOHN NEWTON, of 79 Mark Lane in the City of London, in the county o
Middlesex, Merchant, and DANIEL ARTHUR QUIGGIN, of 28 Chapel Street, Liverpool
in the county of Lancaster, 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 apparatus for condensing steam, for heating or cooling fluids or evaporating
water, it is usual to provide a chamber into which open the ends of a number of tubes
forming heating or cooling surfaces the other ends of the tubes opening into a second
chamber similar to the first.
The fluid to or from which heat is to be 'transmitted enters one chamber, passes
through the tubes and is discharged from the second chamber; the second fluid from
or to which heat is to be transmitted surrounding the outside of the said tubes, being
contained in a suitable chamber.
The circulation of the fluids may be natural or may be produced by any suitable
means.
According to our present invention we provide our apparatus for condensing steam,
for heating or cooling fluids or evaporating water, with tubular heating or cooling
surfaces consisting of one or more coils of metallic tubing whose cross-section is
crescent shaped, the horns of the crescent being rounded; and the outer and inner
bounding circles may or may not be concentric. When the tube is formed into a
cylindrical spiral coil, the horns of the crescent lie on the outside of the coil. The
ends of the tubes may be of circular cross-section to facilitate their attachment to
the tube plates.
We manufacture such coiled tubes from tubes of circular cross-section as
follows:-
We employ a mandrel on which we form a helical groove, the bottom of the groove
being a semicircle of the same or nearly the same diameter as the tube to be coiled,
and the depth of the groove being greater than the radius of the semicircle.
The mandrel is carried in a lathe or other suitable machine by which it can be
rotated.
We secure one end of the tube to be coiled to the mandrel, the tube lying in the
groove thereof. We also employ a 'sliding saddle or frame which can travel parallel
to the axis of the mandrel, and it is driven by suitable gear so as to move over a
distance equal to the pitch of the helical groove while the mandrel makes one
revolution.
On this sliding saddle or frame we fix a pair of jaws of wood or other suitable
material which grip the tube with an adjustable degree of tightness and guide the
tube into the groove, and keep it in tension, while the mandrel is rotated.

page_text: In order to press the tube into the groove and give it the desired section, we
attach to the before mentioned sliding saddle or frame an indenting wheel or roller
which bears on the tube at or about the point where the latter is a tangent to the
mandrel.
The wheel or roller is capable of being adjusted in a direction radial to the
mandrel, and the central portion of its rim which is semicircular in form presses
the tube into the groove and gives it the desired crescent shaped form of cross-
section as the coiling proceeds. The wheel or roller fits laterally into the groove and
has a shoulder at each side, which shoulders bear on the horns of the crescent, and
it may have a second shoulder at each side which abuts against the top of the ridges
between the grooves on the mandrel.
An indenting die of suitable configuration may be substituted for the wheel or
roller already described.
By adjusting the wheel or die radially, as the coiling proceeds, the form of the
tube section can be varied, so that its area may gradually diminish towards one end
of the tube.
Where found necessary to more effectually guide the tube into the groove, a guide
to embrace the tube may be fixed to the saddle between the jaws and the mandrel,
and as close as possible to the latter.
The mandrel may have more than one helical groove, so that more than one
tube can be operated upon simultaneously, each tube being guided and pressed as
described.
In order that our invention may be readily understood, reference is made to the
accompanying drawings which form part of this specification, in which Fig. I is a
sectional elevation and Fig. II an elevation of a cylindrical spiral or helical coil
constructed. according to our present invention, and Figs. III to XV inclusive
illustrate the process of manufacturing the same and the apparatus employed
therein.
Throughout the drawings similar parts are indicated by the same reference
figures.
Referring to Figs. I and II, 1 is the cylindrical spiral coil, brazed to the unions
or connecting pieces 2 by means of which it is readily attached to the diaphragms or
tube plates 3. If diaphragms are not used, the unions 2 are modified to suit the
circumstances of the case.
As shown, the ends of the tube forming the coil are of circular cross-section, whilst
the helical portion of the tube has a crescent shaped section, the horns of the crescent
lying on the outside of the coil. This form of coil is specially applicable where the
fluid from which heat is to be transmitted is steam. The steam enters the coil at
the end where the area of the section is largest and as it is gradually condensed, the
area available for its passage gradually diminishes. If preferred, however, the helical
portion of the tube may have throughout a uniform crescent shaped section.
We prefer to coil the tube so as to leave a space between its successive convolutions
in order to give the surrounding fluid free access to every part.
Fig. III is an elevation, partly in section, and Fig. IV is a plan of part of the
apparatus used in the manufacture of the coil shown in Figs. I and II.
4 is a mandrel having the helical groove 5 to receive the tube 17 which is to be
coiled.
6 is a lathe-bed fitted with the sliding saddle 7 operated by the traversing screw 8;
the remaining parts of the lathe, which is of the ordinary screw-cutting type, are
omitted from the drawings. The screw 8 is geared to the lathe spindle by change
wheels in the ordinary way so that when the mandrel is rotated between the centres
of the lathe, the saddle 7 traverses a distance equal to the pitch of the groove 5 for
each revolution of the mandrel.
9 are jaws of wood or other suitable material tightened by the nuts 10 and carried
on the bracket 11 fixed to the saddle 7.
12 is an indenting roller carried, so that it can rotate freely, by the sliding bracket 13

page_text: :
which can be traversed vertically upon the bracket 14 by the feed screw 15 and
handle 16. As shown, the bracket 14 is carried on the saddle 7.
Fig. X shows to a larger scale the groove 5 in the mandrel 4 with the tube 17
lying in it and the roller 12 bearing against the tube. As shown, the roller fits
laterally within the groove. The central portion 18 of its rim is semi-circular, and
it has at each sile a shoulder 19, which shoulders bear upon the horns of the crescent
when the latter is fully formed, and it has also at each side a shoulder 20 which abuts
against the top of the ridge upon the mandrel and so limits the distance to which
the roller can be fed into the groove. These shoulders 20 may however be dispensed
with if desired.
The process of making a coil such as is shown in Figs. I and II from a tube of
circular cross-section is carried out as follows:-
One end of the tube 17 is threaded between the jaws 9 and secured in the groove 5
by the clamp 21. The nuts 10 are screwed down so as to grip the tube and keep it
in tension as the coiling proceeds and the roller 12 is screwed down so as to bear
upon the tube.
The mandrel is now rotated and as the coiling proceeds the roller 12 is screwed
down so as to press the tube into the groove and give it the desired crescent shaped
form of cross-section.
If it is desired that the section of the helical portion of the tube be made practically
uniform, the roller 12 instead of being screwed down as the coiling proceeds is at
once adjusted to the proper position. When the coiling is completed the upper jaw 9
is removed; the roller 12 withdrawn, the mandrel removed from the lathe centres,
and the clamp 21 being relaxed the coil can be readily removed from the mandrel.
Figs. V and VI show a form of the apparatus which is exactly similar to that
already described except that an indenting die 22 carried on a sliding bracket 23
which can be traversed horizontally on the slide 24 is substituted for the roller 12 and
the brackets 13 and 14. A plan of this die with the tube and groove in position is
shown to an enlarged scale in Fig. XI.
In Fig. IX is shown a modification of the mandrel 4 by which the necessity for
screwing down the roller 12 as the coiling proceeds is obviated.
The diameter of this mandrel at the bottom of the groove is constant from end
to end but the diameter over the tops of the ridges diminishes from one end to
the other.
The axis upon which the mandrel rotates, that is to say, the line of centres of the
lathe, is inclined to the direction of the motion of the saddle 7; the amount of this
inclination being such that if the roller 12 be adjusted to bear against the ridges at
one end of the mandrel, it will continue to do so as it traverses the length of the
mandrel. The position of the roller relatively to the mandrel is shown in full lines
for the beginning and in dotted lines for the completion of the coiling process.
It is obvious that this kind of mandrel may be used in conjunction with the die 22
instead of with the roller 12.
Figs. VII, VIII, XII XIII XIV and XV show details of a modified form of die
for giving the tube its desired section, which may be substituted for the roller 12
already described.
Fig. VII is an elevation partly in section and Fig. VIII is a plan showing the die
in position.
Fig. XII is a sectional elevation to a larger scale on the line A A of Fig. VIII
and Figs. XIII XIV and XV are sectional elevations on the lines B B, C C, D D
respectively of Fig. XII.
25 is the upper and 26 the lower part of the die. They are drawn together
and attached to the bracket 11, between the mandrel and the jaws 9 by the stud and
nut 27.
Each part of the die is grooved to receive the tube, the groove in the lower part 26
being semicircular or approximately so throughout, while that in the upper part varies
as shown in Figs. XIII, XIV and XV, the object being that as the tube is drawn

page_text: through the die in the process of coiling it will assume the desired crescent shaped
cross-section.
The tube may be coiled with a variable or a uniform cross-section accordingly as
the nnt 27 is or is not adjusted as the coiling proceeds.
As the die 25-26 is subjected to a very powerful pull by the tube during the
coiling process, we provide a ledge 28 for the die to abut against. This ledge is
notched to clear the tube.
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. The use in apparatus for condensing steam, for heating or cooling fluids or
evaporating water of a spiral coil or spiral coils of metallic tubing the cross-section
of which is crescent shaped and manufactured substantially as set forth.
2. The manufacture of spiral coils of metallic tubing the cross-section of which is
of a crescent shape, the area of the cross-section thereof gradually diminishing from
one end of the coil to the other while the perimeter remains of constant length,
substantially as described.
3. The combinations of parts forming respectively apparatus for corrugating or
indenting tubes that may be employed in apparatus for condensing steam, for heating
or cooling fluids or evaporating water, substantially as herein described and illustrated
respectively in Figs. III, IV and X, in Figs. V VI and X1, in Figs. VII, VIII, XII
XIII, XIV and XV and in Fig. IX.
D
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