Improvements in or Additions to Steam Loops or Apparatus for Returning the Water of Condensed Steam to Steam Boilers or Generators.
Year: 1891

page_text: Date of Application, 16th Feb., 1891
Complete Specification Left, 5th Nov., 1891-Accepted, 12th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in or Additions to Steam Loops or Apparatus for
Returning the Water of Condensed Steam to Steam Boilers or
Generators.
We HENRY LEA of the firm of Henry Lea and Thornbery of No. 38 Bennett's
Hill Birmingham in the County of Warwick Consulting Engineers and HENRY
PATTMAN TRUEMAN of No. 3 St. George's Terrace Hockley Birmingham afore-
said Mechanical Engineer do hereby declare the nature of this invention to be as
follows:-
Our invention consists of improvements in or additions to steam loops or.
apparatus for returning the water of condensed steam to steam boilers or
generators for which steam loops or apparatus Letters Patent were granted to
Walter Burnham on the 18th day of December 1888 No. 18435.
In the said patented steam loops when the condensed water has to be conveyed
from a point in the system of steam pipes where there is but little pressure the
piping of the loop must rise to a great height in order to return the condensed
water into the steam boiler or a complicated arrangement of steam loops must be
adopted and in some cases there may not be sufficient steam to work the loop. In
order to remedy these and other inconveniences attending the use of steam loops
as ordinarily constructed we have invented the improvements in or additions to
steam loops hereinafter described by the use of which additions or improvements
the pressure in the steam boiler may be maintained as high as may be required for
any particular purpose and the steam pressure within the heating pipes or coils
may be maintained as low as may be desired even below atmospheric pressure and
the whole of the water of condensation will be automatically returned to the steam
generator.
In carrying our invention into effect we provide a closed vessel preferably
cylindrical and of a height of several times its diameter containing a metallic coil of
pipe or surrounded by a jacket which we will call the primary coil or jacket and
into which we conduct high pressure steam from the steam boiler. The said
vessel may be placed at any convenient distance below the steam boiler. From
the bottom of the primary coil or jacket described we lead the water of conden-
sation to a steam loop which returns it to the steam boiler as is well understood.
The arrangement we have described forms a closed circuit containing steam at or
near boiler pressure and kept clear of water by means of the steam loop.
From the interior of the closed vessel we lead a pipe to the pipes or, coils or
apparatus which require to be heated by steam at a low pressure as aforesaid.
We will call these the secondary pipes or coils. From the lowest level of the
secondary pipes or coils we lead a return pipe to the bottom of the interior of the
closed vessel thus forming a secondary closed circuit having no inter-communication
with the primary closed circuit.
Into the closed vessel we admit preferably by slow degrees a certain quantity
of water which may be hot water led through a pipe from the bigh pressure boiler
or may be cold or hot water pumped or allowed to flow in from any suitable source.
We provide an ordinary water gauge upon the closed vessel to indicate the height
of the water within it and we provide also a steam pressure gauge and a safety
valve set to blow off at the required low pressure of steam.
The operation. of the apparatus is as follows:-The primary coil or jacket is
heated by the high pressure steam and in its turn heats the water within the closed
vessel and converts some of it into steam which passes to the secondary pipes or
coils. heating them. becoming condensed and then flowing back as water to the

page_text: closed vessel which is preferably placed at a low level for that purpose; or the
said vessel may be placed at a higher level and may be provided with a secondary
steam loop led from it to the closed vessel. If steam of a very low pressure is
required in the secondary system we introduce but a small quantity of water into
the closed vessel. As then but a small portion of the surface of the primary
steam coil or jacket is in contact, with the water the latter receives therefrom but
a small quantity of heat and furnishes but a small quantity of steam. By
increasing the depth of water in the closed vessel more of the primary coil or
jacket surface is covered and more steam is generated within the vessel. Only
that portion of the primary coil or jacket which is in contact with water acts as a
steam generator the remainder above the water level being inactive as a steam
generator but ready to act as required when the water level has been raised so as
to cover it. The whole of the steam condensed in the primary coil or jacket is
returned by the steam loop to the high pressure steam boiler. The whole of the
steam condensed in the secondary pipes or coils returns by gravitation or by means
of the secondary steam loop to the closed vessel.
In order to supply water to the closed vessel to make up for leakage or waste or
to raise the water level when desired we admit water in the manner hereinbefore
described. If it be desired to reduce the power of the closed vessel by lowering
the water level we open a cock or valve and allow some of the water to escape.
If we allow all the water to escape then the secondary system becomes inactive
and the secondary pipes or coils grow cold although the primary coil or jacket may
continue to be heated by the high pressure steam.
Thus by our invention we avail ourselves of all the advantages of high pressure
steam and the use of a steam loop while at the same time we independently regulate
the quantity and pressure of steam in the secondary pipes or coils no reducing
valve being required.
Instead of adding to or diminishing the quantity of water within the closed
vessel we sometimes arrange within it a movable primary coil more or less of which
we immerse in the water the volume or height of the water then remaining constant.
As another alternative we sometimes provide a movable piston whose position can
be adjusted within a cylinder in such a way as to determine what proportion of a
constant volume of water shall be placed in contact with the primary coil or
jacket.
Dated the 16th day of February 1891.
W. T. WHITEMAN,
Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or Additions to Steam Loops or Apparatus for
Returning the Water of Condensed Steam to Steam Boilers or
Generators.
We, HENRY LEA, of the firm of Henry Lea and Thornbery, of No. 38 Bennett's
Hill Birmingham, in the County of Warwick Consulting Engineers and HENRY
PATTMAN TRUEMAN of No. 3 St. George's Terrace, Hockley, Birmingham,
aforesaid Mechanical 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 :-
Our invention consists of improvements in or additions to steam loops or
apparatus for returning the water of condensed steam to steam boilers or
generators for which steam loops or apparatus Letters Patent were granted to
Walter Burnham on the 18th day of December 1888, No. 18435.
In the said patented steam loops, when the condensed water has to be conveyed
from a point in the system of steam pipes where there is but little pressure, the
piping of the loop must rise to a great height in order to return the condensed

page_text: water into the steam boiler; or a complicated arrangement of steam loops must be
adopted and in some cases there may not be sufficient steam to work the loop. In
order to remedy these and other inconveniences attending the use of steam loops
as ordinarily constructed we have invented the improvements in or additions to
steam loops hereinafter described, by the use of which additions or improvements
the pressure in the steam boiler may be maintained as high as may be required for
any particular purpose and the steam pressure within the heating pipes or coils
may be maintained as low as may be desired even below atmospheric pressure and
the whole of the water of condensation will be automatically returned to the steam
generator.
In carrying our invention into effect we provide a closed vessel, preferably
cylindrical and of a height of several times its diameter, containing a metallic
coil of pipe or surrounded by a jacket which we will call the primary coil or
jacket and into which we conduct high pressure steam from the steam boiler.
The said vessel may be placed at any convenient distance below the steam boiler.
From the bottom of the primary coil or jacket described we lead the water of
condensation to a steam loop which returns it to the steam boiler as is well
understood.
The arrangement we have described forms a closed circuit containing steam at
or near boiler pressure and kept clear of water by means of the steam loop.
From the interior of the closed vessel we lead a pipe to the pipes or coils or
apparatus which require to be heated by steam at a low pressure as aforesaid.
We will call these the secondary pipes or coils. From the lowest level of the
secondary pipes or coils we lead a return pipe to the bottom of the interior of the
closed vessel, thus forming a secondary closed circuit having no inter-communication
with the primary closed circuit.
Into the closed vessel we admit, preferably, by slow degrees a certain quantity
of water, which may be hot water led through a pipe from the high pressure boiler;
or may be cold or hot water pumped or allowed to flow in from any suitable source.
We provide an ordinary water gauge upon the closed vessel to indicate the height
of the water within it, and we provide also a steam pressure gauge and a safety
valve set to blow off at the required low pressure of steam.
The operation of the apparatus is as follows:-The primary coil or jacket is
heated by the high pressure steam and in its turn heats the water within the closed
vessel and converts some of it into steam which passes to the secondary pipes or
coils heating them, becoming condensed, and then flowing back as water, to the
closed vessel, which is preferably placed at a low level for that purpose; or the
said vessel may be placed at a higher level and may be provided with a secondary
steam loop led from it to the closed vessel. If steam of a very low pressure is
required in the secondary system we introduce but a small quantity of water into
the closed vessel. As then but a small portion of the surface of the primary
steam coil or jacket is in contact with the water the latter receives therefrom but
a small quantity of heat and furnishes but a small quantity of steam. By
increasing the depth of water in the closed vessel more of the primary coil or
jacket surface is covered and more steam is generated within the vessel. Only
that portion of the primary coil or jacket which is in contact with water acts as a
steam generator, the remainder, above the water level, being inactive as a steam
generator, but ready to act as required when the water level has been raised so as
to cover it. The whole of the steam condensed in the primary coil or jacket is
returned by the steam loop to the high pressure steam boiler. The whole of the
steam condensed in the secondary pipes or coils returns by gravitation or by means
of the secondary steam loop to the closed vessel.
In order to supply water to the closed vessel to make up for leakage or waste, or
to raise the water level when desired we admit water in the manner herein before
described. If it be desired to reduce the power of the closed vessel by lowering
the water level we open a cock or valve and allow some of the water to escape.
If we allow all the water to escape then the secondary system becomes inactive

page_text: and the secondary pipes or coils grow cold although the primary coil or jacket may
continue to be heated by the high pressure steam.
Thus, by our invention we avail ourselves of all the advantages of high pressure
steam and the use of a steam loop, while at the same time we independently
regulate the quantity and pressure of steam in the secondary pipes or coils, no
reducing valve being required.
Instead of adding to or diminishing the quantity of water within the closed
vessel we sometimes arrange within it a movable primary coil more or less of which
we immerse in the water, the volume or height of the water then remaining
constant. As another alternative we sometimes provide a movable piston whose
position can be adjusted within a cylinder in such a way as to determine what
proportion of a constant volume of water shall be placed in contact with the
primary coil or jacket.
And in order that this our said invention may be the better understood we will
now proceed to describe it by the aid of the accompanying drawings. The same
letters of reference denote the same parts in every figure in which they occur.
The drawings are mainly diagrammatic only, the details of the apparatus
consisting of ordinary pipes, cocks and valves and other parts such as are well
known.
Figure 1, Sheet 1, is a sectional elevation of an apparatus constructed according
to one of the arrangements of our invention.
Figure 2 is a sectional elevation of similar apparatus having a steam jacket
around the closed vessel instead of a coil within it and with the secondary heating
coil placed below the closed vessel.
Figure 3 is a section of part of a modification showing a movable primary coil
in a raised position in the closed vessel.
Figure 4 is a similar section to Figure 3, but showing the primary coil in a
lowered position in the closed vessel.
Figure 5 is a section of part of another modification showing a fixed primary
coil with a piston in a lowered position in the closed vessel.
Figure 6 is a similar section to Figure 5 but with the piston in a raised position
in the closed vessel.
Figure 7 is a section showing a primary steam jacket with a piston in a lowered
position in the closed vessel.
Figure 8 is a similar section to Figure 7 but with the piston in a raised position
in the closed vessel.
Figure 9 Sheet 2 is a section of a portion of the apparatus we employ for
supplying water to the closed vessel of the apparatus as hereinafter described.
We will first describe the arrangement of our invention shown in Figure 1: a is
a closed vessel, preferably cylindrical, of a height several times its diameter and
containing a coil of metallic pipe b. This we call the primary coil. Into the
primary coil we conduct high pressure steam through the pipe a from the boiler
or steam generator d. The pipe c is provided with a stop valve c'. In place of
one primary coil, two or more coils or straight or curved pipes may be employed.
The vessel a may be placed at any convenient distance below the steam boiler d.
From the bottom of the primary coil we return the water of condensation to the
boiler d through a Burnham's patent steam loop e, e', e³, e³ of which e¹ is the riser,
e the horizontal part and the drop leg.
The arrangement so far described forms a closed circuit hereinafter called the
primary circuit containing steam at or near the boiler pressure, and kept clear of
water by means of the steam loop.
From the interior of the closed vessel a, and at or near its highest point, we lead
a pipe to the pipes or coils or apparatus g which are required to be heated by
steam at a low pressure. In Figure 1 the coil is at a higher level than the
vessel a. From the lowest part of the coil 7, we lead a return pipe to the
bottom of the vessel a (Figure 1).
The pipe with the coil g and the return pipe h form a second closed circuit,

page_text: nereinafter called the secondary circuit, having no inter-communication with the
primary circuit. Into the vessel a we admit, preferably by slow degrees a certain
quantity of water say to the level of a¹. The water may be obtained through the
piper from the boiler d or from any other suitable source of supply through the
pipe k. The quantity of water admitted is controlled by the valve or k¹ as
the case may be. We provide a water gauge to show the height of the water
within the vessel a; also a steam pressure gauge m, and a safety valve n, the latter
being set to blow off at, or a little above, the required low pressure of the steam
in the secondary circuit.
Instead of using a coil of pipe for the high pressure steam in the primary
circuit, a steam jacket u may be used as shown in Figures 2, 7 8 and 9.
Before proceeding to describe the modifications of our invention as shown in
Figures 2 to 9, both inclusive we will describe the action of the apparatus as
shown in Figure 1; the action in the modifications will then be very readily
understood.
The primary coil is heated by high pressure steam passing into it from the
boiler through the pipe c.
The primary coil heats the water in the vessel a, and converts some of it into
steam, which passes through the pipe f into the secondary pipes or coil g which is
or are thereby heated and the heat from which may be utilized for warming
buildings, heating water, wort, or other liquid or for any other purpose to which the
heat of low pressure steam may be applied.
The steam in passing through the pipes or coil is condensed into water which
returns by gravitation through the pipe to the closed vessel a which is placed at
a lower level than the coil g. If steam at a very low pressure is required in the
secondary system we introduce but a small quantity of water into the vessel a.
As then but a small portion of the primary steam coil is in contact with the
water, the latter receives therefrom but a small quantity of heat and furnishes but
a small quantity of steam.
By increasing the depth of water in the closed vessel a more of the primary coil
surface is covered and more steam is generated within the vessel a.
Only that
portion of the surface of the primary coil b which is in contact with the water acts
as heating surface to generate steam, the remainder, above the water level, being
inactive, but ready to act as required when the water level is raised. The whole
of the water which is condensed in the primary coil while heating the water, is
returned to the boiler d by the steam loop e, e', e², e³. The whole of the water
which is condensed in the secondary coil 9 while warining a building, heating
water, or wort, or the like is returned to the closed vessel a by the pipe ..
If it be desired to reduce the quantity of steam generated in the closed vessel a
we lower the water level by opening a cock or valve p whereby some of the water is
allowed to escape. If we allow all the water to escape, then the secondary circuit
becomes inactive and the secondary pipes and coils f, g, become cold although
the primary coil may continue to be heated by the bigh pressure steam from
the boiler d. Thus, by our invention while using steam from a boiler which is
being worked for other purposes at a high pressure, we obtain steam for the
secondary circuit at any desired low pressure, no reducing valve being required,
and the whole of the low pressure steam being condensed, if necessary, without
interfering with the action of the steam loop which continues.to return the con-
densed water to the boiler from which in the form of steam it was derived
Figure 2 is a sectional elevation of a modification of our invention in which
modification the secondary pipes or coils y are at a lower level than the closed
vessel a. The action of the apparatus is precisely the same as that shown in
Figure 1 and already described except that the water condensed in the secondary
coils is returned to the closed vessel a by means of a steam loop o, o o instead of
by gravitation. In Figure 2 we have shown in place of a coil within the vessel a
an alternative arrangement consisting of a jacket u surrounding the vessel a into
which jacket u steam is led from the boiler by the pipe the supply being
g

page_text: controlled by the stop valve c¹. In this case the amount of low pressure steam
generated in the vessel a and utilized in the secondary circuit depends as before
described upon the level of the water in a, that part only of the heating surface
of the jacket being available which is in contact with the water in the vessel a.
Instead of increasing or diminishing the quantity of water within the closed
vessel a we sometimes arrange within it a movable primary coil b as represented
in Figures 3 and 4, more or less of which we immerse in the water, the volume
of water then remaining constant. In Figure 3 the primary coil b is shown raised
nearly out of the water whereby only a small quantity of low pressure steam
would be generated for use in the secondary circuit, while in Figure 4 the coil b
is almost wholly immersed in the water whereby a much larger quantity of low
pressure steam will be generated.
In another modification shown in Figures 5 and 6, we employ a fixed primary
coil and a movable piston 7 forming the bottom of the vessel a. The volume of
water in the vessel a remains constant as in the modification last described. The
position of the piston q determines how much of the primary coil b is covered by
the water.
Figures 7 and 8 show a similar modification having a jacket u instead of a
coil b.
In Figures 3 to 9, both inclusive, only the closed vessel a with the parts imme-
diately appertaining thereto are drawn, it is however to be understood that the
other parts of the apparatus are similar to those shown in Figure 1 or in the
modification shown in Figure 2.
Figure 9, Sheet 2, shows a modification in the method of varying the quantity
of water in the closed vessel so as to vary the extent of primary coil or jacket
surface in contact with the water, whereby the regulation of the quantity of water
is rendered automatic.
From the bottom of the closed vessel a is led a bent pipe s terminating in an
open vessel or tube t.
When the steam pressure in the vessel a exceeds the pre-
determined pressure the water in a is thereby partially expelled and rises in the
vessel whereby a less extent of primary jacket or coil surface in a is covered
with water. When the steam pressure in a falls, the head of water in the
vessel forces some of the water to return into the vessel a so as to cover. a
larger extent of jacket or coil surface. The difference between the water levels
in a and t determines the pressure at which the steam will be maintained or
approximately maintained in the secondary circuit.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed we declare that we
claim as our invention of "Improvements in or additions to steam loops or
apparatus for returning the water of condensed steam to steam boilers or
generators":-
First Interposing between the steam boiler, generating steam of high pressure,
and the steam loop, apparatus substantially of the kinds herein before described and
illustrated in Figures 1 and 2 for generating steam of low pressure, the said low
pressure steam generating apparatus receiving steam at or near boiler pressure and
being kept clear of water of condensation by the steam loop, and the combination
with the low pressure steam generating apparatus of a closed circuit or system of
pipes or coils to be heated by the steam from the low pressure steam generating
apparatus, the heat of the said pipes or coils being utilized for heating purposes,
the water of condensation from the system of heated pipes or coils being returned
to the low pressure steam generating apparatus by gravitation or by a steam loop,
the several parts being arranged and acting substantially as hereinbefore described
and illustrated in Figures 1 and 2 of the accompanying drawings.
Secondly:-The arrangement shown in Figures 3 and 4 for varying the extent
of primary coil surface in contact with the water in the closed vessel of the
apparatus claimed in the first claim,

page_text: Thirdly The arrangement shown in Figures 5, 6, 7 and 8 for varying the
extent of primary coil or jacket surface in contact with the water in the closed
vessel of the apparatus claimed in the first claim.
Lastly-The arrangement shown in Figure 9 for automatically varying the
5 extent of water in contact with the primary coil or jacket surface of the closed
vessel of the apparatus claimed in the first claim.
Dated the 3rd day of November 1891.
HENRY LEA.
HENRY PATTMAN TRUEMAN.