Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to an electric steam
generator of the type havin~ at least one electrode disposed in
a vessel, and further including a distribution device for
directing water to be evaporated against the electrode in the
form of jets.
In known steam generators of this type, the electrodes
are arranged vertically about a centrally located distribution
device and being operatively connected to a three-phase network.
In use, a current flows through the water jets so that part of
the water jets evaporates. The steam formed in this manner is
collected in the vessel and i~ then fed to the steam consumers
while the unevaporated water returns to a sump loca~ed in the
lower part of the vessel and forms further current paths. If
the consumption of electric power changes, a larger or smaller
number of the water jets emanating from the distribution device
is intercepted in these known steam generators so as not to
reach the ele~trodes. It is a drawback of ~he known steam
generators that because of the vertical arrangement o the
elec~rodes and of the distribution device, the steam generator
has a relatively large overall height as r due to the curved
water~jets, it is necessary to provide intercept area of the -
electrodes to be of required size in vertical directionO
It is an object of -the pxesent invention to provide
a steam generator of the above mentioned type, whose overall
height is smaller than in the known prior art devices, and whose
steam generating capacity relative to the volume of the generator
is increased.
The present invention solves the above object hy an
arrangement wherein the elec~rode is formed as a horizontally
extending~dish for receiving a supply of water having openings
forming outlets for the received water to f~rm vertical water the
jets. The distributi~n means has a chamber to receive water,
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chamber having an approxima-tely horizontal bottom and h~ving a
group of openings above the dish-shaped electrode for directing
vertical water jets against the electrodeO Due to the fact that
the openings in the distribution means are arranged in a
horizontal plane and the electrode is in the form of a horizontal
dish, the height of the electrode and thereby, the overall height
of the steam generator, can be reduced substantially. This
makes it possible to accommodate the steam generator according
to the present invention in a basement of a normal story height
in dwellings, hospitals, and similar buildings. Due to the
dish-shaped form of the horizontal electrode and the horizontal
arrangement of the openings in the distribution means, a uniform
vertical straight-line path of the water jets emanating from the
distribution means is obtained. This makes it possible to
increase the steam generating capacity over vertically arranged
electrodes.
In general terms, the present invention provides, . -
in an electric steam generator, the combination comprising; at
least one horizontally extending dish-shaped electrode in said
vessel for receivlng and~heating a supply of water and having
openings therein forming outlets for the received water to form
vertical water jets; a distribution mea.ns located above said
at least one electrode, said distribution means having a chamber
to receive water, said chamber including a horizontal bottom
having a group of openings above each of sald at least one :: -
electrode for directing vertical water jets against and into
each of said at least one electrodei means mounted for movement
between each of said at least one electrode and said distribution :.
means for selectively intercepting the flow of water in said -.-
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water jets between said distribution means~and each of said at ~:
least one electroda; and means for selectively moving said
~: intercepting means across~said latter water jets to intercept .~ :
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and to divert away from each of sa.id a-t least one electrode a
number of said latter water jets proportional -to the distance
moved between each of said at least one electrode and said
distribution means.
The present invention will be described in greater
detail with reference to two embodiments shown in the accompanying
drawing, of which one has been made the subject of a divisional
application.
In the Drawings:
Figure 1 is a vertical section of a steam generator
according ~o the present inVentiQn;
Figure 2 is a section along lines II II of Figure l;
Figure 3 is a vertical section of another steam
generator, now subject of the said divisional application;
Figure 4 is a partial section IV-IV of Figure 3;
Figure 5 is a partial section V-V of Figure 3 and
Figure 6 is a section VI-VI of Figure 4.
Referring to Fig. 1, the electric steam generator
has a cylindrical vessel 1 disposed on a vertical axis which ~;
is provided at the top and ~ottom with a convex cover 3 and
2 respectively. The diameter of the vessel 1 is approximately
equal to the height o e the vessel, so that the vessel 1 is of
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compact sh~pe. A pipe elbow 4 is connected to the lower cover 2
and is connected via a flange joint to an intake stub 5 of a
circulatlng pump 7, which is driven by an eIectric motor 6. An
output stub 8 of the circulating pump 7 is flanged to a central
pipe 10 which passes through the lower cover 2 and extends close
to the upper cover 3. The lower end of the pipe 10 is cylindrical
and changes toward the top to a triangular cross-section with
rounded corners tsee Fig. 2). ~ pipe line 50 is connected to the
lower cover 2 through which feed water is supplied by means of
a feed pump ~not shown~ and forms a sump in the lower par of
vessel 1.
A plane intermediate plate 12 is provided below the
mouth of the central pipe 10 in the vicinity of the upper cover
3 or at the same height as this mouth. This intermediate plate
12 is part of a distribution means for the water to be evaporated
which water collects on the intermediate plate 12 as a layer of
a certain height. At approximately half height o the vessel 1
three dish-shaped electrodes 20 are provided in a horizontal
plane, uniformly distributed over the circumference. Each
electrode 20 consists of an approximately horizontal bottom 21
and a frame 22 welded thereto, which extends upward and has a
segment-shaped top elevation (see Fig. 2). The bo~tom 21 is
equipped with sixty-six noæzles 55, the exit openings of which ,!
are arranged at the in~ersection points o~ two amilies of
involutes 26 which are mirror-symmetrical to a radial plane
including the axis o the ~essel 1~ Several mutually parallel
grid bars 25 are fastened above the nozzles 55 in the frame 22,
which form a grid and are omitted in Fig. 2 ~o the left o~ ~he
~ break llne b for the sake of clarity.
A collecting grid 15 is prov1ded below each electrode -
20 which conaists of steel strlps 16 arranged on edge sid~ by-
side and rests via four leqs 14 on the lower cover 2. Each
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electrode 20 is supported via two ceramic insulators 18 on the
collecting grid 15 located underneath. For this purpose, the
grid 15 has two overhanging pla~es 17. The insulators 18 lns~late
the respective electrode 20 electrically against the collecting
grid 15. Current is supplied to the three elec~rodes 20 via a
bar 41 each of which is connected at one end to the bottom 21
of an electrode 2~ via a connecting strip 43 and is brought out
at the other end through a radially disposed stub 42 of the
vessel 1. ~he bars 41 are enclosed by insulators 40. The three
phases of a ~hree-phase network are connected to the outer ends
of the bars 41 in a manner not shown in detail.
A group of several nozzles 13 is associated with each
electrode 20 and are disposed in the intermediate plate 12 to
define openings through which vertical water jets are directed
against the associated electrode 20. The arrangement of the
noz~les 13 corresponds to that of the no~zles 55 in the electrode
20. A pipe line Sl is connected to the vessel 1 closely below
the intermediate bottom 12 and conducts the saturated steam
generated in thevessel 1tO the consumers (not shown).
:: 20 ~ Furthermore, the intermediate bottom 12 is:provided
on its lower side with a pipe section 28 which is concentric with
the central pipe 10 and has a flange 29 at a lower end. The
flange 29 has an annular slot of circular cross-section on the
upper side in which balls 30 roll and a ring 31 of angular
cross-section extends over ~he balls 30 so that an axial bearing
is formed. Three collecting trays 35 are distributed
circumferentially over the ring 31 and are welded to the ring
31. Each tray 35 is associated with one of the three groups of
nozzles 13 and can be swung into the area of the water jets
coming from the nozzles 13. ~ach of ~he collecting t.rays 35 is
provided with a spout 36 ~Fig. 2) which is pointed toward the
wall of the vessel 1 and can move, together witt the collecting
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tray 35, over the opening of a collecting
pocket 38. The collecting pockets 38 are each formed by a metal
sheet 56 which is welded to the inside of the vessel and extends
downward to shortly above the water sump. If the collecting
trays 35 are swung into the area undernea~h the nozzle 13, part
o~ the water jets is thereore intercepted by means of the
collecting trays 35 and the water collected is conducted into the
collecting pockets 38, so that this intercepted water does not
come into contact with the electrodes 20 and therefore does not
carry current.
The operation of the steam generator is as follows:
By means of the circulatiny pump 7, water is drawn from the sump
and pumped via the cen~ral pipe 10 onto the intermedlate bottom
12, where a water layer is formed, the height of which depends
on the amount of water pumped by the circulating pump 7 and on the
sum total of the exit cross sections of all nozzles 13. A pipe
52 is provided for pressure equalization between the space above
and the space below the intermediate plate 12. This pipe 52 also
serves as an overflow. The water collec~ing on the intermediate
bottom 12 is distributed over the nozzle 13 and falls in a
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~ 20 multiplicity o ve~tical jets onto the grid 25 of the dish-shaped
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electrodes 20. The water collec~s in these dishes forming a
level.i~ Then, the water 10ws via the no~zles 55 onto the
collecting grid 15 underneath and from there to the sump. The
current fed in vla the bars 41 flows from the dish-shaped
electrodes 20 on;the one hand against the falling water, to the
nozzles 13 and on the other hand, in the same direction as the
falling water; to the collecting grid 15. The nozzles 13 as
; well as the connecting grids 15 are electrically connected to
the vessel 1 and are at zero potential. When the current passe~
throu~h the w~ter jets, steam i generated. The steam is then
collected belQw the intenmediate plate 12 and leaves the vessel
via ~he line 51.
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At full load of the s-team generator, the three
collec-ting trays 35 are outside the area of the water jets issuing
from the nozzles 13. For a smaller load, the ring 31 with the
three collecting trays 35 is moved counter-clockwise in Fig.
by a suitable means ~not shown).so ~hat the collecting trays
intercept a larger or smaller part of the water issuing from
the nozzles 13. The collected water flows via the spouts 36
into the collecting poc]cets 38 and returns to the water sump.
By the specific arrangement o the nozzles 13 and 55 at the
points of interception of two equidistan~ families of involu~es,
the number of water jets covered.. by the collecting trays 35 :~
is varied approximately linearly as a function of the angle of
rotation. ..
. It may be advantageous to pjro~ide partitions abou~
the individual nozzles 55 at the bottom of t~e dish-shaped
electrodes 20 in such a manner that the water leaves the dish
in appxoximately the same axis as the watex enters. It is
also conceivable to arrange partitions in the dishes in such
a manner th t the w~ter is not distri.buted over a larger area
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or a larger number o~ jets leaving the electrodes than
Gorresponds approximately to the number of ~he jets flowing
towards the electrode. Finally, the heic~ht o~ the partitions
can be arranged in steps. In this manner, at low load, the
; water which is fed-in in only a few jets can be prevented from
discharging rom~ too ~large a number of jets.
Instead of equipping the bottoms 21 and the-inter-
mediate plate 12 with nozæl~ 55 and 13, respectively, it is
. also possible to work nozzle-shaped discharye openings into the
bottom 2~1 or .the:plate 12 itself.
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3~ In the: ste~am generator shown~in ~igures 1 and 2,
means are provided whereby~- for~a partial load of the steam
generator - the water flowin~ toward the electrode is fed only
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to a part of the openings in the electrode. This means consis~s
of a movable in~ercepting device which can be moved into the
space between the distribution device and the electrode located
underneath in order to prevent more or fewer water jets from
striking the electrode. However, such a steam generator still has
a relatively large overall height because -the distance between
the upper side of the electrode and the underside Qf the
intercepting device inserted below the distribution device must
not be less than a certain value as otherwise there is danger
~ of the current arcing over.
In the embodiment o Figures 3 to 6, the
distribu~ion means is arranged to be movable in a hori~ontal
direction from its position above the electrode in a direction
away from the electrode. The collecting means is mounted in
stationary manner in the vessel between the water distribution
means and the electrode vertically out of alignment with the
electrode, to intercept the watex jets which are not to strike
the electrode. As the water distxibution means i5 movable
and the collec~ing means is stationary, the distribution means
can be arranged closer to the el ctrode, while the collecting
means remains outside of the curren~-carrying water jets. Thus,
the overall height of the steam generator can be further reduced.
Referring to Fig. 3, ~he steam generator comprises
a cylindrical vessel 1 which is disposed on a vertical axis
and is provided at its bottom cover 2 to communicate with a
suction stub 5 of a circulating pump 7. ~n output stu~ 8 of
the pump 7 is connected to a flanged pipe StU~ 10 which is
centrally located of the vessel 1 and protrudes upwardly throu~h
the vessel bottom cover 2. The pipe stub 10 terminates at a
- 30 flan~e 65 somewhat belo~ the le~el of the water sump formed on
~he hottom 2. A bearing;ring 66~of angular cross-section is
a~ranged on the flange 65 to surround ~he flanye 65 on the outside
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with a downward directed rim. A vertical pipe 67 is mounted on
the bearing ring 66 to rotate about the axis of the ~essel. This
pipe 67 is formed at the lower end with an inward projecting
flange 68 which rests on the bearing ring 66. The section of
the pipe 67 located below the flange 68 encloses the outer
circumference of the bearing ring 66. ~hus, the bearing portion
is bridged by the water of the sump acting as an electric
conductor. Therefore, there are only negligibly small voltage
differences between the bearing surfaces; so that corrosion due
to voltage differences is avoided~
The upper end o~ the rotatable pipe 67 terminates
in a hexagonal housing 69 which has a rectangular opening 70 in
each of three walls. The three openings 70 are thus arranged
; at an angle of 120 to each other. A distribution box 72 which
is open at the top and is bolted to the respective wall of the
housing 69 via gaskets (not shown~ is connected to each opening
70 to form a chamber to receive water. ~he distribution boxes
72 have the shape of a truncated sector as seen in a top view
(Fig. 4). The horizontal bottom of each distribution box 72
is~provided an opening in the shape of a ring sector 73 which
is covered from~below by a nozzle pla~e 75 which is fastened
to the bottom of the distribution box 72 by means of screws 74.
The nozæle plate 75 has a group of nozzle openings 76
which are arranged in rows in such a manner that the rows are
slightly askew to the axis of rotation of the pipe 67. Referring
to Figs. 4 and 6, each distribution box 72 has a slightly
inclined sheet of metal plate 79 near one boundary wall 72'
' which forms a slot 78 for the chamber. ~s shown, the slot 7
~ widens towards the top. The plate 79 func~ions as a partition
~ to sepaxate the slot 78 from tbe~remainder of the chamber in
the box 72 such that ~he slot 7~ can function as an over~low
opening~
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In order to drive the pipe 67, a rotatable drive
sh~ft 80 is bolted to a cover 69' of the hexagonal housing 69
via a flange and extends through the upper end, i.e. cover 3,
of the vessel 1. In addition, a stuffing g1.and 81 i5 mountéd
in the.cover 3 to seal the drive sha~t 80 in the cover 3. Iihe
drive shaft 80 is in connection with drive means (not sho~n)
via which a rotar~ motion o about 45 can be imparted to the
rotatable pipe 67 including the three distribution boxes 72,
and more specifically, clockwise from the position shown in Fig. 4
and back again. The collection device formed by the collecting
dishes 95 is thus disposed within the vessel 1 in a stationary
fashion~
As bes~ seen from Fig. 4, three horizontally extending
dish-shaped electrodes 88 are arranged underneath the full-load
position of the distrihution boxes 72 spaced by 120 over the
circumference of the vessel 1~ Each of these eIectrodes 88 is
supported by a conduc~or rod 87 which projects into the vessel
space radially and is mounted in a stub 85 of the vessel. The
: conductor rods 87 serve to supply current and are each surrounded
by an insulator~86. Each electrode 88 consists of a horizontal
bot~om 89 and an adjoining upward-extending frame 91. The bottom
89 is provided with no~zle outlets 90, which are arranged,
corresponding to the nozzle openings 76 of the distrihution
boxes :72, in xows which are slightly askew to the axis of the
rotatable pipe 67. Vertical partitions ~4 are pxovided between
each two adjacent rows of nozzle outlets 90 and extend from the
bottom to about 2/3 o~ the height of the frame 91. Collecting .:
: ~ rods g2 are:fastened to the frame 91 above partitions ~4 and run :~
crosswise to the partitions 94 and ex~end in the vertical
direction. A collecting ~rid 35 is~provided below each electrode
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88 to collect the:water jets from ~hè electrode 88. Each
collecting grid 15:is fastened to ~wo brackets 15' which are
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welded to the inside of the vessel l and protrude horizontally
into the vessel space ~ig. 5~,
Referring -to Figs. 3 and 4, a collecting means
is moun~ed in stationary manner within the vessel 1 in a horizontal
plane between each water distribution box 72 and an associated
electrode 88. Each collecting means includes a collecting dish
95 which is secured, as by welding, to a vertical run-off pipe
96. The run of~ pips 95 are fastened by means of U-bolts
97 to U-shaped strip steel brackets 98, which are welded to
the wall of the vessel 1. As seen in Fig. 6, the upper left
boundary edge 99 of each collecting dish 95 runs approximately
radially to the pipe 67 and extends, in the position of the
distribution box 72 shown in Fig. 4, underneath this box 72
between the slot 78 and the row of the row o nozzle openings
76 adjacent to this slot 78.
In the operation of the steam generator, water is
taken from the sump of the vessel 1 by mea.s of the circulating
. pump 7 and pumped ~ia the cen~ral pipe 10 and the ro-tatable ~.
pipe 67 into the:three distribution boxes 72~ The three dis-
20 tribution boxes 72 thus ~orm a water chamber in wh~ch the water
to be evaporated collects as a layer of a certain height~ From
the distribution boxes 72, the water passes via the no~zle
openings 76 to the associated electrode 88 in the form of water
jets while any excess pumped by the circulating pump 7 flows . ~.
over the upper edge of the~plate:79 into the ovexflow slot 78 :;
and thence into the associated collecting dish 95. For full . ~ p
load, the distribution boxe;s 72 are in the positian shown in
Fig. 4, i.e. vertically over the electrodes 88, so that a]l the ~:
water jets issuing from the:nozzle openings 76 strike the
electrodes 88. The~;excess~water flowing out from the slots 78
- returns via the collectin~dishes 95 and the run of pipes 96
.
to the sump. The water o-E the water jeks coming fxom the boxes :-
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72 collects row by row between the partitions 94 of the dish
shaped electrodes 88 and is distributed anew and flows via the
outlets 90 to the collecting grid 15, again in the form of jets.
The three-phase current fed~in via the three conductor rods 87
flows from the dish-shaped electrodes 88 on the one hand toward
the noz~le plates 75, against the falling water, and on the other
hand, in the direction of the falling water, to the collecting
grids 15. The nozzle plates 75 as well as the collecting grids
15 are electrically connected to the vessel 1 and are at zero
potential. During the passage of the current, steam is generated
which collects under the top~cover 3 and is conducted via
a line 51 to consumers ~not shown). The amount of steam leaving
the vessel 1 is replaced by feed water, which is ~ed to the
vessel 1, via a line 50 connected to the bottom cover 2 by means .
: of a feed water pump, not shown.
If the load is reaucedr the p~pe 67 is rota~ed via the
~: dr-ive shaft 80 so that the distribution boxes 72 are gradually
moved away from the associated electrode 88 in the hori~ontal
direction clockwise as viewed in Fig. 4. Thus, one jet after
2Q the other from each box 72 no longer s~rikes the associated
electrode 88 and is received by the associated collecting dish
95 from where the water is returned to the sump via the
run-off pipe g6. .Accordingly, the steam generation is reduced
while the electrlc voltage remains constant.
: A.man hole stub 100 is provided in the cylindrical
. wall of the vessel 1 through which all components of the steam
g nerator -can be brought into the vessel .-1 and assembled.
The steam generator according to t~e-invention may
also be equipped with oniy one electrode instead of with three
electrodes.
The invention is not:limited to vessels with a
vertiral axis~ It is also possible to use cylindrical vessels
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with a horizontal axis, in which case, the dish-shaped electrodes
are arranged staggered in the direction of the horizontal axis.
Accordingly, also the distrib~ltion boxes are then arranged to
be axially movable.
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