Year: 1897

page_text: Date of Application, 17th July, 1897
Complete Specification Left, 16th Apr., 1898-Accepted, 18th June, 1898
I, HERMANN SEIFFERT, of 17, Thuringerstrasse, Halle a/Saale, in the German
Empire, Engineer and Manufacturer, do hereby declare the nature of this inven-
tion to be as follows:-
:-
The object of this invention is to provide a steam-boiler or generator with means
whereby, without external aid (such for example as pumps and injectors for inject-
ing heated water into hot tubes) a more copious and rapid generation of steam can
be produced than is practicable with the steam-generators heretofore employed.
The new and essential feature of my improved method of generating steam
consists in that, by means of a special device, highly heated water is mixed with
steam and is automatically injected directly into a vaporizer by the pressure in the
boiler whilst reducing the specific pressure of the highly heated water.
In applying my improvements to a Cornish, Lancashire or other flame-tube
boiler I provide the same with a large steam-dome over the grate-end of the
furnace, and I mount above the boiler two cylinders extending parallel with the
axis of the boiler; these cylinders are so arranged that they cannot be directly
acted upon by the fire-gases but are heated by radiant heat through suitable
apertures in the arch which cuts them off from the upper flue. The purpose of this
arrangement is to enable the flame-tube boiler to be worked at a higher pressure.
than the said cylinders.
One of the cylinders, forming the vaporizer, is in communication with the flame-
tube boiler through a mixing apparatus (which is arranged within the steam dome
and, dips beneath the same into the water of the boiler) a connecting pipe and
distributing jets or nozzles. With the other or second cylinder, which forms the
steam-collector, the first cylinder is connected through a superheating coil arranged
above the fire-tube boiler in the upper flue.
The heating gases generated in the flame-tube or furnace of the boiler, are drawn
through the same, rise up at the back, simultaneously bathe the upper half of the
boiler-shell and the said super-heating coil, then move forward, downward and
backward passing along the lower half of the boiler-shell to escape into the
chimney.
The method of generating steam is as follows, viz.:-The highly heated water
is removed from the flame-tube boiler at the hottest part thereof by means of the
mixing device, is mixed with the steam generated in the flame-tube boiler and led
through the connecting-pipe to the distributing jets or nozzles through which it is
blown in a finely divided condition, into the vaporizer which, as above mentioned,
works at a lower pressure than the boiler. By the reduction of pressure in the
vaporizer, the generation of steam is rendered very rapid at that place. The steam
so generated passes through the superheating coil to dry it, and thence to the
steam-collector from which it is conducted for use.
The mixing device whereby the steam collecting in the steam-dome is mixed with
the highly heated water, forms an essential part of my invention.
Within the steam-dome is a vertically arranged immersion-tube which is open.
at the bottom and connected at the top to the pipe feeding the distributing nozzles;
the said tube is surrounded at its middle part with a co-axial tube of larger diameter.

page_text: which is closed at the top and bottom by screw-threaded caps, flanges or other
suitable means and is perforated at its upper part. Within the said immersion-
tube is mounted a conical nozzle which may be termed the "mixing" nozzle and
which is in communication, through lateral apertures at its base, with a passage
of annular cross-section formed between the immersion-tube and the tube surround-
ing the same; the said mixing nozzle opens at the top into the said immersion-tube
so that the steam which collects in the dome above the water-level passes through
the holes or perforations at the top of the outer tube into the said annular passage,
enters the mixing nozzle through the lateral apertures thereof and thence issues
through the upper aperture or jet thereof into the upper part of the immersion-tube
whence the mixture of steam and water passes off to the distributing nozzles.
At the highest position of the water-level, and consequently at the commence-
ment of firing the boiler, the water in the boiler stands above the upper opening of
the mixing nozzle and at the same height within the annular passage, so that the
steam space of the dome is cut off or isolated. As steam collects in the dome, it
exerts pressure on the surface of the water which consequently rises up in the
immersion-tube, passes through the connecting pipe and the distributing nozzles
into the vaporizer and thence enters the superheating coil. In this manner the
superheating coil is automatically prevented from becoming red-hot during the
firing of the boiler.
At the same time the water-level in the steam-dome falls to its middle position
which is at the same height as the outlet-opening of the mixing nozzle.
On further generation of steam and further falling of the water-level the water,
still remaining at the same height in the annular space between the immersion-
tube and the tube around the same, is forced out through the mixing nozzle because
as the height of the water-level decreases, the excess pressure of the steam over the
water at the outlet part of the said nozzle increases, this excess pressure depending
upon the height of the column of water up to the water-level.
The outlet-aperture of the mixing nozzle is made of such size that the issuing
steam must have a high velocity. For this reason the steam issuing from the said
nozzle into the immersion-tube exerts an inductive action on the water in the
boiler, so that the difference of pressure above mentioned between the steam and
water is balanced and at the same time a certain impulse is imparted to the water.
The back-pressure which exists at the opening of the nozzle has no influence on the
action of the mixing device. Therefore an uniform quantity of highly heated water
and steam is supplied to the distributing nozzles independently of the pressure, this
water and steam being injected into the vaporizer (which works at a lower pressure)
by reason of the reduced pressure therein."
If there is a more rapid generation of steain in the flame-tube boiler so that the
whole of the steam generated cannot escape through the mixing nozzle with the
same velocity, the excess pressure of the steam over that of the water increases,
which depresses the water-level and causes an increase of the velocity at which the
steam passes out, and at the same time produces an increase in the steam-space.
The same effect is obtained by a modification of this mixing device hereinafter
mentioned. In this modified arrangement, the mixing nozzle, which is mounted in
the immersion-tube, forms the shorter limb of a U-shaped tube which is introduced
from below into the said immersion-tube whilst the other limb terminates in the
steam-space of the dome at the upper part thereof. The mouth of the mixing nozzle
is likewise arranged at a height corresponding to the mean position of the water.
The action of this modified arrangement will be clearly understood from what is
mentioned above without further explanation.
The supply of water to the distributing nozzles is regulated by means of a valve
arranged in front thereof. The distributing nozzle is only duplicated in case one
of them should get out of order. Should this take place, the cock behind the
particular distributing nozzle and the corresponding valve is closed, so that the 5
distributing nozzle can be taken out and put in order without interrupting
the working of the boiler;

page_text: An important feature of the arrangement above mentioned is that nearly the
whole surface of the flame-tube boiler can be used as heating surface so that its
dimensions can be considerably smaller than ordinary flame-tube boilers with the
necessary steam-space.
Empire, Engineer and Manufacturer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described:
and ascertained in and by the following statement:-
The object of this invention is to provide a steam-boiler or generator, with means
whereby, without external aid (such for example as pumps and injectors for inject-
ing heated water into hot tubes). a more copious and rapid generation of steam can
be produced than is practicable with the steam-generators heretofore employed.
The new and essential feature of my improved method of generating steam
consists in that, by means of a special device,, highly heated water is mixed with
steam and is automatically injected directly into a vaporizer by the pressure in the
boiler, whilst reducing the specific pressure of the highly heated. water:
In the accompanying drawing,.
Figure 1 is a vertical longitudinal section through the steam generator:
Figure 2 is a transverse section, and
Figure 3 is a plan of the same.
Figures 4 and 5 show, separately, and drawn to an enlarged scale, the arrange-
ment of the mixing tube in longitudinal and transverse section, relatively to the
boiler, and
Figure 6 is a modification of this arrangement.
In applying my improvements to a Cornish, Lancashire or other flame-tube
boiler, I provide the same with a large steam-dome K over the grate-end of the
furnace, and I mount above the boiler two cylinders D and E extending parallel with
the axis of the boiler; these cylinders are so arranged that they cannot be directly
acted upon by the fire-gases but are heated by radiant heat through suitable
apertures in the arch which cuts them off from the upper flue. The purpose of this
arrangement is to enable the flame-tube boiler to be worked at a higher pressure
than the cylinders D) and E.
One of the cylinders, D, forming the vaporizer, is in communication with the
flame-tube boiler through a mixing apparatus A, (which is arranged within the
steam dome and dips beneath the same into the water of the boiler), a connecting
pipe B C and distributing jets or nozzles S. With the second cylinder E, which
forms the steam-collector, the first cylinder D is connected through a superheating
coil G arranged above the fire-tube boiler in the upper flue:
The heating gases generated in the flame-tube or furnace of the boiler, are drawn
through the same, rise up at the back, simultaneously bathe the upper half of the
boiler-shell and the said super-heating coil, G, then move forward, downward and
backward, passing along the lower half of the boiler-shell to escape into the
chimney.
The method of generating steam is as follows, viz.; The highly heated: water
is removed from the flame-tube boiler at the hottest part thereof by means of: the

page_text: mixing device A, is mixed with the steam generated in the flame-tube boiler and
led through the connecting pipe B C to the distributing jets or nozzles S through
which it is blown, in a finely divided condition, into the vaporizer D which, as
above mentioned, works at a lower pressure than the boiler. By the reduction of
pressure in the vaporizer D, the generation of steam is rendered very rapid at that
place. The steam so generated passes through the superheating coil G to dry it,
and thence to the steam collector E, from which it is conducted for use.
The mixing device A, whereby the steam collecting in the steam-dome K is mixed
with the highly heated water, forms an essential part of my invention; the arrange-
ment thereof is more fully shown in Figures 4 and 5.
at
Within the steam-dome is a vertically-arranged immersion-tube s which is
open at the bottom and connected at the top to the pipe feeding the distributing
nozzles S; the said tube is surrounded at its middle part with a co-axial tube a of
larger diameter, which is closed at the top and bottom by screw-threaded caps,
flanges or other suitable means and is perforated at its upper part. Within the
immersion-tubes is mounted a conical nozzle , which may be termed the
"mixing" nozzle, and which is in communication, through lateral apertures
its base, with a passage h of annular cross-section formed between the immersion-
tubes and the tube a surrounding the same; the said mixing nozzle opens at the
top into the immersion-tube s, SO that the steam which collects in the
dome K above the water-level passes through the holes or perforations at the
top of the outer tube into the annular passage h, enters the mixing nozzle d through
the lateral apertures e, and thence issues through the upper aperture or jet thereof
into the upper part of the immersion-tube s whence the mixture of steam and water
passes off to the distributing nozzles.
At the highest position of the water-level, and consequently at the commence-
ment of firing the boiler, the water in the boiler stands above the upper opening of
the mixing nozzle and at the same height within the annular passage h, so that the
steam-space of the dome is cut off or isolated. As steam collects in the dome, it
exerts pressure on the surface of the water which consequently rises up in the
immersion-tube, passes through the connecting pipe B C and the distributing
nozzles S into the vaporizer D and thence enters the superheating coil G. In this
manner the superheating coil is automatically prevented from becoming red-hot
during the firing of the boiler.
At the same time the water-level in the steam-dome falls to its middle position
which is at the same height as the outlet-opening of the mixing nozzle d.
On further generation of steam and further falling of the water-level, the water,
still remaining at the same height in the annular space h between the immersion-
tube s and the tube a around the same, is forced out through the mixing nozzle d,
because, as the height of the water-level decreases, the excess pressure of the steam
over the water at the outlet part of the said nozzle increases, this excess pressure
depending upon the height of the column of water up to the water-level.
The outlet-aperture of the mixing nozzle d is made of such size that the issuing
steam must have a high velocity. For this reason, the steam issuing from the said
nozzle d into the immersion-tube s exerts an inductive action on the water in the
boiler, so that the difference of pressure above mentioned between the steam and
water is balanced and at the same time a certain impulse is imparted to the water.
The back-pressure which exists at the opening of the nozzle has no influence on
the action of the mixing device. Therefore an uniform quantity of highly heated
water and steam is supplied to the distributing nozzles S, independently of the
pressure, this water and steam being injected into the vaporizer D (which works
at a lower pressure) by reason of the reduced pressure therein.
If there is a more rapid generation of steam in the flame-tube boiler M so that the
whole of the steam generated cannot escape through the mixing nozzle d with the
same velocity, the excess pressure of the steam over that of the water increases,
which depresses the water-level and causes an increase of the velocity at which the
steam passes out, and at the same time produces an increase in the steam-space.

page_text: The same effect is obtained by a modification of this mixing device shown in
Figure 6. In this modified arrangement, the mixing nozzle d, which is mounted
n the immersion-tube s, forms the shorter limb of a U-shaped tube p, which is
introduced from below into the said immersion-tube s, whilst the other limb
terminates in the steam-space at the upper part of the dome K. The mouth of the
mixing nozzle d is likewise arranged at a height corresponding to the mean position
of the water. The action of this modified arrangement will be clearly understood
from what is mentioned above without further explanation:
The supply of water to the distributing nozzles S is regulated by means of a
valve V arranged in front thereof. The distributing nozzle is only duplicated in
case one of them should get out of order. Should this take place, the cock H behind
the particular distributing nozzle S, and the corresponding valve V, is closed so
that the distributing nozzle can be taken out and put in order without interrupting
the working of the boiler.
An important feature of the arrangement above mentioned is that nearly the
whole surface of the flame-tube boiler can be used as heating surface so that its
dimensions can be considerably smaller than ordinary flame-tube boilers with the
necessary steam-space.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
-
1. The introduction of highly-heated water from a boiler into a vaporiser working
at lower pressure, by mixing steam generated directly in the boiler with water
from the said boiler and passing the mixture through a spraying nozzle, so that,
by the action of the steam during the egress of the mixture from the spraying
nozzle into the vaporiser and the reduction in pressure, a spraying or comminution
of the water and a more rapid generation of steam will be obtained.
2. An apparatus for carrying into practice the process of generating steam,
herein before described, comprising a steam-jet or nozzle mounted in an immersion-
tube which is open at the bottom and is surrounded by an outer tube closed at its
ends and perforated near the top so as to open into the steam-space of the boiler,
whilst the said nozzle is in communication, through the holes or perforations in
the outer tube, with the steam-space and opens or discharges at about the height of
the mean position of the water-level, so that, when, in the generation of steam, the
water-level falls below the mean position, the water standing between the inner and
outer tubes will be forced out through the nozzle, whereupon the steam issuing
through the nozzle will act inductively on the water in the boiler and cause an
uniform mixture of water and steam to be supplied to the vaporiser, substantially
as described.
3. The modification of my invention in which the steam-nozzle in the immersion-
tube forms one limb of a U-shaped tube, the other limb of which opens into the
steam-space at a higher level, substantially as described.
4. A steam-generator provided with my improved apparatus constructed substan-
tially as described with reference to Figures 1 to 5, or to Figure 6 of the accompany-
ing drawings and operating as, and for the purposes, above specified.
16th day at
-AM
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.