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Патент USA US2119100

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2,119,100
Patented May 31, 1938
UNITED STATES
PATENT OFFICE
2,119,100
STEAM GENERATING PLANT'
Hans Conrad Egloñ‘, Winterthur, Switzerland,
assignor to Sulzer Freres Societe Anonyme,
Winterthur, Switzerland
Application March 6, 1935, Serial No. 9,606
In Switzerland March 9, 1934
3 Claims. (Cl. 60--94)
This invention relates to series steam gener
ators in which the working medium is fed as liq
uid to one end of a tube system and is taken off at
the other- end as superheated steam, the tube
5
system being appropriately supplied with heat.
In such steam generators as usually construct
ed, the quality, or condition, of the steam de
livered by the generator is controlled by means
of regulating devices which regulate the gener
10 ator heat supply, the supply of feed liquid and
the output of steam. For plants of small output,
however, such regulating devices occupy consid
erable space in comparison with the steam gener
ator itself; their operation causes a considerable
15 loss of output.
The regulation of steam generators of this type
is greatly simplified if the superheating of the
working medium in all conditions of operation is
made to commence at one and the same point of
20 the tube system. In fact, it has heretofore been
proposed to draw off the liquid working medium
at a predetermined point in the tube steam sys
tern by means of a liquid separator, and to con
vey only the dry saturated steam to the super
heating zone, but the separated liquid was either
led back to the feed supply of the tube system, or
led away out of the range of the steam plant.
In accordance with the present invention, the
separated liquid is no longer conducted back to
30 the high pressure steam generator, nor is it led
away out of the range of the steam plant, but it
is led to a low pressure steam generator working
as an accumulator. With this arrangement, de
vices for regulating the quantity of the high pres
sure working medi-Lun are not necessary but nev
ertheless, the flexibility of the steam plant is pre
served. By the fact that no working medium is
led away out of the range of the steam plant, the
supplying of additional working medium to take
40 the place of that conducted out of the steam plant
is unnecessary, and consequently the danger of
introducing feed liquid which is contaminated
with deposit-forming materials is lessened. A
saving of energy also results, because the heat of
45 the working medium drawn from the high pres
sure steam generator is recovered in the low pres
sure part of the system.
The pressure of the steam delivered by the
steam generator can, in certain cases, be regu
lated according to the amount of heat supplied
to the generator, the pressure being higher when
the heat supply is large than when the heat sup
ply is reduced.
The quantity of liquid Working medium dis
charged from the liquid separator may be regu
lated, in accordance with the invention, by means
of a device whose operation depends upon the
height of the surface of the liquid within the sep
arator.
The take-off pipe from the separator
may also be provided with a now-limiting device
for limiting the ñow of steam therethrough, but,
at the maximum operating pressure of the steam
generator, permitting liquid to flow through the
same at the maximum rate at which liquid work
ing medium is supplied to the steam generator.
The invention will be described in connection
with the embodiment thereof shown, by way of
example, in the accompanying drawing. In this
drawing:
Fig. 1 illustrates diagrammatically a steam 15
plant, or system, according to the invention;
Fig. 2 is a sectional view of a detail.
v
Fig. 3 shows a modified construction of one of
the elements of Fig. 1, and
Fig. 4 illustrates a further modification of this
element.
'Referring now to the accompanying drawing,_
a high pressure water tube steam generator I
produces steam which >is used for operating a
steam engine 2, the steam exhausted from this
engine being conveyed in part to the heating ele
ment 20 of a low pressure accumulator 3, and in
part liqueñed in a condenser 4. The condensate
from heating element 200i accumulator 3 and
the condensate from the condenser 4 ílows to a
feed liquid tank 5, from which the feed liquid is
drawn off and conveyed back to the steam gen
erator I by means of a feed pump 6.
The steam generator I comprises two tube sys
tems, or coils, 8 and I0 suitably mounted in an
appropriate furnace structure to which heat is
supplied, as will be described below. These two
tube systems are connected in series, and the
working medium is fed at a uniform rate, as liq- ,
uid, to the lower end 1 of tube system 8. The
liquid is in part evaporated in tube system 8 and
arrives as a mixture of vapor and liquid at the
separator 9, where the vapor is separated from
the liquid and ñows on through tube system I0
which operates as a superheater. The superheat
ed steam is led from the upper end II of super
heater I0 through pipe I2 to the high pressure
cylinder’or stage I3 of the steam engine 2. Man
ually operated valve I4 is provided in steam line
I2 for regulating, if necessary, the quantity of 50
steam flowing to the engine. After expansion in
the high pressure stage I3, the steam flows
through a pipe I5 to a four-way connection I6,
from which, according to the existing pressure
conditions, it is conveyed either through pipe I1
2
2,119,100
and governor valve 2l to the low pressureA cylin
der or stage I 3 of engine 2, or through the line
I9 to the heating element 29 of the low pressure
steam generator 3, as previously mentioned.
A speed governor 22 of the engine 2 actuates
governor valve 2I and thereby controls the quan
tity of steam flowing to the low pressure stage I8
in such a way that on an increase of the engine
speed, the flow cross section of governor valve 2l
10 is decreased, and on a reduction of speed, is in
creased. The steam discharged from loW pres
sure stage i5 is conveyed through line 23 to con
denser 4, in which it is condensed by means of the
cooling coil 24 which is appropriately'supplied
with cooling water, the amount of steam thus
conveyed to condenser 4 depending upon the pow
er output of engine 2. The'condensate is re
moved from condenser 4 by a pump 25 through
line 25, and is conveyed through line 21 to the
feed liquid tank 5. The liquid level in this tank
can be observed by means of a gauge `23.
The
portion of steam delivered to four-way connec
tion I6, which is not required by the low pressure
stage I8 of engine 2, is condensed in heating ele
ment 29 of low pressure generator 3. Thus the
amount of heat supplied to low pressure gener
ator 3 in this manner, depends upon the power
output of engine 2.
Heating element 29 is submerged in the body
30 of liquid working medium contained _within low
pressure generator 3 and it will be understood
that heat from the working medium within heat
ing element 20 is transferred to this body of
liquid, thereby causing ebullition and the gener
35 ation of steam within the shell of low pressure
generator 3. The condensate from heating ele
_ment 29 is conveyed by means of pipe 29 to the
feed liquid tank 5.
'
The liquid working medium separated in the
40 liquid separator 9 is conveyed through the line
39 to the heating element 20 of low pressure
generator 3, the heat contained in this liquid
thereby being used for the production of >low
pressure steam, together with the heat of the
45 vapor entering heating element 20 through line
I9.
I, the pressure in line I2 will increase, and when
a predetermined pressure is reached, a pressure
operated valve 31 is opened. This permits the
steam to pass from line I2 through line 36 into
line 38. From line 38 the steam is conveyed by
means of a branch pipe 39 to the four-way con
nection I6, from which, in case the low pressure
stage I8 of engine 2 does not take the steam, it
flows into heating element 20. Should the con
ditions be such that it is impossible for heating 10
- element 20 to condense the steam at a suiñciently
high rate, then the surplus steam passes off
through a safety valve 48 to the atmosphere.
In case the steam produced by the steam gener
ator I is temporarily not sufûcient to meet the 15
steam requirements of engine 2, the steam plant
is so arranged that as soon as the steam pres
sure from generator I falls, low pressure steam
from the generator 3 is immediately made avail
able for operating the engine 2. For this pur
pose the steam is led from the steam space of
generator 3 through a pipe 4I to a pressure
controlled valve 43 and thence through line 39
to four-way connection I5, pipe I1 and the low
pressure stage I8 of engine 2.
Pressure-controlled valve 43 is actuated by
25
means of a piston 42 operating in a cylinder, the
upper end of which is connected to pipe 38 so
asy to be inñuenced by variations in the pressure
of steam delivered from generator I through lines 30
I2 and 36 and valve 31. When, therefore, the
pressure of the steam produced by generator I
falls, the pressure upon the upper side of piston
42 is reduced, thereby allowing spring 44, on the
lower side of piston 42, to open valve 43.
35
If desired, a portion of the steam produced by
low pressure generator 3 may be conveyed by
means of lines 45 and 45 to other steam-consum
ing devices (not shown), such, for example, as
heating devices or additional steam engines. For
regulating the pressure in line 46, there is pro 40
vided a second pressure-controlled valve 41, the
valve member of which is controlled by means of
piston 48.
In case of a rise in pressure in line
46, piston 49 is forced downwardly thereby, and
The liquid Working medium from separator . causes the flow cross section of valve 41 to be de 45
creased, and conversely, upon a fall of pressure
9, after passing’through heating element 20, is
carried, along with the condensate resulting from
the lique?ication of the vapors from line I9,
50 through line 29 to feed liquid tank 5.
A flow-limiting device 32 is provided in line
39 for limiting the maximum rate of discharge
of working medium from separator 9, and so for
preventing the discharge of an appreciable
55 quantity of steam through line 30. A manually
operated valve 3| is placed in line 30 for the pur
pose of cutting off the flow of liquid from sepa
rator 9, and for the purpose of regulating the
rate of flow of this liquid as desired.
60
The liquid working medium conveyed through
line 39 from separator 9 can also be led directly
into the shell of low pressure steam generator
3 by means of line 34 which is connected with
the lower portion of the shell of generator 3.
65 Valves 33 and 35 are arranged to control the ?low
of the liquid from separator 9 for this purpose.
In this way, the liquid from separator 9 is added
to the liquid working medium in low pressure
generator 3, and the heat contained in the liquid
70 from separator 9 is transferred directly to the
body of liquid in generator 3 instead of indirectly
by means of the heating element 28.
In the event that the amount of steam con
sumed in the high pressure stage I3 of engine
75 2 is less than that produced by steam generator
in line 4S, spring 49 urges piston 48 and its
connected valve member upwardly, thereby in
creasing the iiow cross section of valve 41.
In order to replace losses of working medium 50
occurring in the high pressure circuit, an aux
iliary condenser 58 is provided to which steam is
conveyed through pipe 5I
condensate from condenser
52 into line 29, and thence
The feed liquid from tank
from line 45. The
50 is led through pipe
to feed liquid tank 5. 55
5 is delivered to feed
pump 6 for generator I by means of pump 55
and line 56.
The “make-up” liquid working medium for
low pressure generator 3, and in fact for the en 60
tire system, is drawn from a tank 58 by means
of a pump 51 which delivers the make-up liquid
through pipe 59 to a feed heater 68 heated by the
flue gases of generator I. From this heater, the
make-up liquid flows through pipe 8l into the 65
bottom of generator 3.
A safety valve 10 is provided to prevent the
pressure within generator 3 from becoming too
high. Generator 3 is provided also with a circu
70
lating pump 53, connected in a circulation pipe
54 for the purpose of regulating the circulation of
liquid working medium within generator 3.
A particular form of now-limiting device 32 for
limiting the maximum flow of liquid from sepa 75
3
2,119,100
rator 9 is shown in Fig. 2. As shown in this ñgure,
the flow-limiting device comprises a nozzle 62,
the flow cross section of which is such that at
the maximum permissible operating pressure of
vices heretofore employed for regulating the tem
perature of this type of steam generator are done
away with, and nevertheless the temperature of
the steam is maintained substantially constant
steam generator I, the nozzle will pass the total
quantity of liquid working medium delivered by
feed pump 6 to tube system 8. As the rate of
ñow of this nozzle is proportional approximately
without the necessity of accommodating within '
the generator a large volume of liquid working
medium, The system of the present invention is
to the density of the medium iiowing through
it, should steam be discharged through nozzle 62
particularly advantageous in connection with
steam generating plants of small and moderate
into pipe 3E, the rate of steam flow would be
much less than the rate of liquid flow. Thus,
for example, with steam flowing through the
nozzle, the weight of steam passing the nozzle>
in a given time and under a given pressure,
size, because of the fact that in these sizes, the
regulating devices occupy a large amount of space
in the steam plant in comparison with the size
of the steam generator itself. Moreover, the ex
pense and difñculty of maintaining such regu
lating devices in proper operating condition is
would amount only to approximately 116 of the
weight of liquid which would .pass through the
nozzle ín the same time. In this way, an auto
matic regulation of the quantity of working me
avoided.
Instead of providing a throttling device in the
discharge line of the separator the height of the
water level in the separator may be regulated.
20 dium drawn from separator 9 is accomplished.
Steam generator I is supplied with heat by
means of a liquid fuel burner 6E to which fuel
is supplied by means of a pipe 65 in which is
located a hand-operated valve 61. The combus
tion air is supplied through a conduit 68 in which
is placed a hand-operated valve 69.
As shown in Fig. 3 a float member âß is provided 20
within the separator.
The float member raises
a valve stem 82 when the water level 8l rises and
increases the cross section for the water dis
charged from the separator. On the other hand
vthe cross section is decreased if the Water level 25
sinks and the position of the valve stem is low
2,5
The operation of the steam producing plant, ered.
In other cases the separator may be suspended
or system, is as follows:
Liquid working medium is supplied to ' the in a yielding manner, for example by a spring 83 30
and connected by a lever 84 with a valve 85, as
30 steam generator I at a constant, or unvarying,
rate by means of feed pump 6, and the output of shown in Fig, 4. The separator is connected by
steam from generator I is regulated by varying means of two flexible tubes 86 and 81 with the
the amount of heat supplied to the generator. steam generator and by a further flexible tube 83
with the accumulator. If there is a great quan
This regulation is accomplished by manipulating tity
of water in the separator, the position of the
burner valves 61 and 69 in accordance with varia
separator is lower than with a smaller quantity
tions of a working condition of low pressure gen
of water. The variation in the height of the sep
erator 3, such, for example, as variations in the rator indicates the quantity of liquid contained
level of liquid working medium in this generator,
which can be observed by means of a gauge B3,
40 or by variations in the pressure of the steam gen
erated by generator 3, which can be observed by
means of a steam gauge B4.
A larger or smaller quantity of the liquid
working medium in tube system 8 of generator
i will be evaporated according to the amount of
heat produced by burner 66. The non-evapo
rated liquid is separated in liquid separator 9 and
conducted away by means of pipe 30, as pre
viously described, and employed for supplying at
least a portion of the heat required for the opera
tion of low pressure steam generator 3, after
which it is re-circulated through tube system 8
of generator I.
_
The regulation of the temperature of the steam
at the discharge end II of tube system I0 of gen
erator I is automatic. This is because of the
fact that with a large supply of heat to generator
I, an increased quantity of liquid is evaporated in
tube system 8 so that a large amount of heat is
required to superheat this large supply of steam
ñowing from separator 9 to superheater I0. Con
versely, when the supply of heat to generator I
is small, the quantity of steam generated is also
small, so that the amount of heat supplied to the
generator is still able to superheat this small
quantity of steam to the prescribed temperature.
It will be understood that instead of the recip
rocating steam engine 2 indicated in the drawing
' as the prime mover of the power plant, one or
more turbines may be employed. Other changes
may be made in the system which come within
the scope of the appended claims, Without de
parting from the invention.
The steam plant of the present invention has
the advantage that more or less complicated de
in it, and this variation is made use to alter the
cross-section of the valve 85 by means of the
lever 84.
I claim:
1. In a steam system adapted to supply power
and heat in fluctuating amounts, a high pressure
tubular continuous-flow steam generator having 45
a, vaporizing zone and a superheating zone, a
pump conveying feed liquid in unvarying amount
to the steam generator, a liquid separator con
nected between the vaporizing and superheating
zones of the steam generator, an engine plant 50
having high and low pressure stages, said high
pressure stage being connected to receive super
heated high pressure steam from the superheat
ing zone of the steam generator, a low pressure
steam generator having a steam receiving heat 55
ing element connected between the low and high
pressure stages of the engine plant, and a pipe
conveying unevaporated liquid from the liquid
separator to the steam receiving heating element
of the low pressure steam generator.
-
60
2. Apparatus in accordance with claim 1 in
which a nozzle is connected in the pipe leading
from the liquid separator to the steam receiving
heating element of the low pressure generator,
said nozzle, at the operating pressure of the 65
steam generator, allowing the total quantity of
liquid feed to the high pressure steam generator
to pass into said heating element.
3. Apparatus in accordance lwith claim 1 in
which a by-pass pipe is provided which during 70
periods of production of excess high pressure
steam by the high pressure steam generator,
leads said steam into the steam heating element
of the low pressure steam generator.
HANS CONRAD EGLOFF.
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