Improvements in and connected with Self-acting Temperature- regulating Devices for Superheaters.
Year: 1898

page_text: Date of Application, 20th May,
1090
Complete Specification Left, 23rd Feb., 1899-Accepted, 26th May, 1899
ppiication, out may, 1090
Complete Specification Left, 23rd Feb., 1899-Accepted, 26th May, 1899
PROVISIONAL SPECIFICATION.
Improvements in and connected with Self-acting Temperature-
regulating Devices for Superheaters.
I, WILDELM SCHMIDT, of Wilhelmshöhe, near Cassel, in the Province of
Hesse-Nassau, German Empire, Civil Engineer, do hereby declare the nature of
this invention to be as follows:
This invention relates to regulating-devices for superheaters and has for its
object to improve the self-acting properties of such devices.
The hereinafter described self-acting device effects the regulation of the
temperature of superheated steam by utilizing the varying temperature of the
steam in such manner, that after the apparatus has been adjusted for a fixed
temperature, no further adjustment of the same is necessary.
As basis of my improvements I have used the known principle of science of
the varying expansion of a body at changing temperatures, which principle I
employ in my novel device, to open to a greater or less extent a valve of a con-
nected receptacle or, to close the same for the purpose of utilizing the varying
steam-pressure in this receptacle itself, to actuate the regulating-device, or in
other words, this expansion movement of the body at changing temperatures is
employed indirectly to produce the necessary direct actuation of the regulating
damper, the movement of the expanded body being too slight a one, to employ
such movement direct, or at least, if such direct employment were possible, it
would not be practicable, as in such a case, a complicated system of levers would
be necessary.
In order to make my invention clear, I refer to the accompanying draw-
ing, in which similar letters denote similar parts throughout the different
views, and in which?
Figure 1 shows my improved regulating-device separately, in vertical section.
Figure 2 is a front-view of Figure 1,
Figure 3a side-view of the superheater in section, with regulating-device
attached, and
Figure 4 a front view of Figure 3.
Referring to Figure 1, a is the steam-pipe through which the superheated
steam passes towards the place of consumption; b is a closed tube (preferably of
iron or steel), which at its free end possesses a small valve-opening.
Upon the said valve opening, there operates in the interior of the tube a metallic
body c preferably arranged also in the form of a tube, said body c having further
a considerably larger coefficient of expansion than the said tube b.
Furthermore the said body c is so regulated by an adjusting-screw f, that at the
ighest desired temperature, the valve-opening to the chamber d is almost entirely
closed, whilst at lower temperatures, this valve, according to the degree of tem-
perature, is correspondingly opened.
The steam passing through the pipe b, when the valve is opened, enters the
receptacle d, which is provided with an outlet, which does not vary in its propor-

page_text: tion or extent, or more precisely, the said outlet always remains opened to the
same degree.
In the construction shown in the drawing this outlet is within the piston, the
section of which is so arranged, that the steam entering through the small re-
gulating valve, can only pass through this outlet when the pressure in the
chamber d has attained a certain height, or more precisely, at a definite velocity
of the outflow of the steam.
The more the inlet-valve opens, the more of course, the pressure in the
chamber d increases, and inversely, when the inlet-valve is closed, the pressure
can entirely, escape.
I have therefore attained, according to the varying steam-temperature, a
changing inlet, and a constant or unchanging, outlet.
It is however clear, that the outlet might also be adjusted by an adjusting
device or adjusting-screw to any previously determined degree.
Thus in the receptacle which at the same time forms a cylinder for the re-
ception of a pistoire, a varying pressure must be produced according to the
changing pressure of the steam temperature; this pressure is now used to actuate
the pistone attached to and weighted by a differential lever (see Figure 3) or by
springs (the principle of the spring-balance), which latter by means of a lever or
the like, and by means of a chain or the like, act upon the regulating-device
according to the changing-position of the piston.
The more the piston is pressed down, the more the weighted lever g (Figure 3)
connected with the draught-damper, moves in a horizontal direction, whereby
the resistance increases.
It will be clear, that instead of employing a piston, as shown, upon which the
changing pressure rests, a membrane or diaphragm may be employed; also it
will be clear, that instead of the rigid body herein before described, a liquid body
for instance mercury, may be employed to influence the inlet-valve.
The heat of the steam which escapes through the outlet-valve or the small
opening of the piston e, may, in order to avoid a loss of this heat, although such
loss is not great, be conducted if necessary to the feeding-water.
Furthermore, the steam in the receptacle or cylinder d, if a sufficient cooling
surface exists, may, be condensed if proper means are provided, to lead away the
condensed water. In the latter case the piston instead of acting by pressure,
may for instance operate by a vacuum.
PE
WILHELM SCHMIDT.
By Robert Deissler,
31A, Luisen Strasse, of Berlin, Germany, Agent.
Improvements in and connected with Self-acting Temperature-
regulating Devices for Superheaters.
I, WILHELM SCHMIDT, of Wilhelmshöhe, near Cassel, in the Province of
Hesse-Nassau, German Empire, Civil 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 : ——
This invention relates to regulating-devices for superheaters and has for its
object to improve the self-acting properties of such devices.
The hereinafter described self-acting device effects the regulation of the
temperature of superheated steam in such a manner, that after the apparatus has

page_text: been adjusted for a fixed temperature, no further adjustment of the same is
necessary.
As basis of my improvements I have used the known principle of science of
the varying expansion of a body at changing temperatures, which principle I
use in my novel device to a greater or less extent, to open a valve of a connected
receptacle, or to close the same for the purpose of utilizing the varying steam-
pressure in the receptacle itself. This expansion movement of the body at
changing temperatures is employed indirectly to produce the actuation of the
regulating damper. At present the movement of the expanded body in regulating
devices acted directly upon the draught damper, but the movement being too
slight a one, the employment of such direct movement would not be practicable,
as in such a case a complicated system of levers would be necessary.
In order to make my invention more clear, I refer to the accompanying
drawings in which similar letters denote similar parts throughout the different
views, and in which:
Figure 1 shows my improved regulating device separately, in vertical section,
Figure 2 illustrates a front view of Figure 1,
Figure 3 is a side-view of the superheater in section with regulating-device
attached,
Figure 4 is a front view of Figure 3.
Figure 5 is a view illustrating the employment of a mercury column.
Referring to Figure 1, a is the steam-pipe, through which the superheated
steam passes towards the place of consumption; b is a closed tube (preferably of
iron or steel), which at its free end is provided with a small valve-opening. A
metallic body e preferably in the form of a tube is arranged within the tube b.
This body has a larger coefficient of expansion than the surrounding tube b, so
that the valve opening provided at the end of the tube will be closed, when the
body expands owing to the raising temperature.
C
The said body can be regulated by an adjusting screw f, so that at the highest
desired temperature the valve opening to the tube is almost entirely closed
whilst at lower temperatures the expansion of the body c will not be sufficient to
effect the closing of the valve and the latter opens more and more according to
the contraction of the body c.
When the valve is opened, the steam passes through the pipe and enters the
receptacle d which is provided with an outlet, the size of the opening of which
can be varied at will by any suitable device. This outlet is so small and con-
structed in such a manner, that the steam only can pass outside when the steam
pressure within the chamber has attained a certain degree.
The more the body contracts, the more the valve of the tube opens. The
steam passes through the tube and the pressure in the chamber & increases.
When the steam inlet valve of is closed, the steam contained in the chamber b
will escape through the outlet and the pressure within. the chamber d lessens.
It will thus be clear that the inlet of steam changes according to the expansion
and contraction of the metallic body c, but that the outlet through the opening
always remains constant in a quantity previously determined by the regulating
device.
The receptacle d forms at the same time a cylinder for the reception of the
piston e. This piston is in connection with the draught damper by means of
levers, chains and the like. In the construction shown in the drawing the piston
rode is connected to a lever k movably attached at upon the carrier, the
draught damper m is drawn into a ring joint n by a weighted lever g. This
lever at its free extremity is provided with a chain, which chain is attached at
the other end to the free extremity of the balance-lever k, so that when the
piston e descends, the motion will be communicated to the balance-lever k and
consequently the chain will be pulled down, the weighted lever g lifted and the
draught-damper m opened.

page_text: The more the lever g approaches its horizontal direction, the greater will be
its resistance.
Suppose now, that the temperature within the superheater has attained the
highest desired degree, the metallic body e will expand and close the valve of the
tube 6. The lever g owing to its own weight will draw the draught damper into
the ring and the joint will be effected. When the lever y descends, the piston e
will raise owing to the chain connection. The fire has now no draught and con-
sequently it will get less intense. The temperature lowers, the body c contracts
and the valve in the tube opens, the steam passes through 6, enters the
cylinder d and escapes through the outlet opening h, thereby pressing the piston
down. The chain gets pulled down, the weighted lever raises, the draught
damper m opens and the fire will have again draught and get more intense. The
same will be the case at any changement of the temperature within the super-
heater. The steam which escapes through the outlet valve h may in order to
avoid a loss of steam, although such loss is not great, be conducted if necessary
to the feeding-water.
It will be clear that instead of employing a piston, as shown in the drawing,
a membrane or diaphragm may be employed; also it will be clear that instead of
the rigid body herein before described, a liquid body, i.e. mercury, may be
employed to influence the inlet valve. The mercury has the same functions as
the metallic body c before explained, it expands and contracts thereby allowing
the steam to enter the chamber d or preventing it from doing so. An example
is illustrated in Fig. 5 of the accompanying drawing. is a column of mercury.
When this mercury expands, the extremity of the mercury column closes the
connection between a and and steam is prevented to pass inte the cylinder d
and inversely.
Having now particularly described the nature of my said invention, and in
what manner the same is to be performed, I declare that what I claim is:-
1. In a self-acting temperature-regulating device for superheaters, the com-
bination of a body having at large coefficient of expansion and adapted to be
influenced by the varying degrees of temperature of the steam, with a valve
actuated by said body, a cylinder provided with constant outlet and fed by said
valve, a piston arranged to be moved by the pressure within said cylinder, and
means to convey the movement of said piston to the draught-damper, substantially
and for the purpose as described.
2. In a self-acting temperature-regulating device for superheaters, the com-
bination of a metallic body having a large coefficient of expansion and adapted
to be influenced by the varying degrees of temperature of the steam, with a valve
actuated by said body, a cylinder provided with constant outlet and fed by said
valve, a piston arranged to be moved by the pressure within said cylinder, and
means to convey the movement of said piston to the draught-damper, substan-
tially and for the purpose as described.
3. In a self-acting temperature-regulating device for superheaters, the com-
bination of a liquid body having a large coefficient of expansion and adapted to
be influenced by the varying degrees of temperature of the steam, with a valve,
actuated by said body, a cylinder provided with constant outlet and fed by said
valve. a membrane or diaphragm arranged to be moved by the pressure within
said cylinder, and means to convey the movement of said diaphragm to the
draught-damper, substantially and for the purpose as described.
Dated this 21st day of February 1899.
ROBERT DEISSLER,
Agents for the Applicant.