Improvements in Apparatus for Heating and Purifying Feed Water and Drying Steam.
Year: 1892

page_text: Date of Application, 21st June, 1892-Accepted, 1st Oct., 1892
COMPLETE SPECIFICATION.
Improvements in Apparatus for Heating and Purifying Feed Water
and Drying Steam.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of
Middlesex Gentleman do hereby declare the nature of this invention (which has
been communicated to me from abroad by Julien Belleville of Saint Denis in the
Republic of France Engineer) and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement :--
The improvements forming the object of the present invention relate to a novel
arrangement of the internal partitions of feed water heating and purifying and
steam drying apparatus for steam generators and more especially for water tube
generators which improvements enable the said apparatus to comply at all rates of
speed with the conditions hereinafter specified.
These conditions are essential to the perfect action of sectional or water tube
steam generators working with forced circulation and are as follows namely―
1st. Energetic stirring or agitation of the feed water by the steam before the
said water comes in contact with the heating surfaces.
2nd. Complete drying of the steam after it has agitated the feed water.
3rd. Effectual performance of the normal cycle of circulation of the feed water
after its agitation by the steam.
The first of these conditions namely the energetic stirring or agitation of the
water by the steam is complied with by means of the arrangements next hereinafter
described. The steam is introduced into the purifier through a series of tubes
(marked B in the accompanying drawings) passed through the under side and
projecting into the interior of the purifier. These tubes are covered by a dome
which receives the steam from the said tubes. The outlet orifice which com-
municates with the return pipe is arranged in such a position that its lower part is
higher than the lower edges of the said steam dome. Consequently the steam
cannot escape from the dome except by bubbling through the layer of water in
which the lower edges of the dome are immersed. It results that this water is
energetically agitated by the currents of steam escaping from the tubes and which
pass through it even when the volume of feed water in the purifier is greatly
reduced and the quantity of water flowing in the return pipe is consequently very
small.
The fresh feed water being introduced at the right hand end of the apparatus for
example flows along each side of the dome in passing to the outlet orifice situated
at the left hand end of the apparatus. In its passage the feed water flows by each
steam tube and is energetically lifted or blown up and heated by the steam escaping
When
through angular openings or notches in the lower edges of the steam dome.
the fresh feed water is finally discharged from the purifier its temperature is the
same as that of the steam.
The elevation of temperature resulting from the forcible agitation of the feed
water by the steam dehydrates the salts which are precipitated in the form of an
uncrystallizable mud.
The second condition namely; the complete drying of the steam after it has
acted upon the feed water is complied with by means of a combination of baffle
plates or partitions forming a circuitous passage which the steam is compelled to
follow and in which it is compelled to repeatedly change its direction in such a
manner as to take from it all the particles of water carried with it in flowing
through the body of water which permanently occupies the lower part of the

page_text: purifier. By means of a suitable arrangement of transverse plates or partitions
provided at both ends of the purifier the steam is compelled to follow the wide
passage presented to it immediately on escaping from the water.
The sectional areas of the different parts of the passage through which the steam
is caused to flow are regulated so that the flow of steam takes place under slight
differences of pressure corresponding to a few centimetres of water. It results that
the steam by coming in contact with the surfaces of the passage and by the sudden
changes of direction is readily separated from the particles of water which it
carried with it on escaping from the water in the lower part of the apparatus.
The third condition namely the effectual performance of the cycle of circulation
of the feed water is complied with in the following manner. The upper ends of
the steam inlet tubes covered by the steam dome are arranged on a level with the
axis of the outlet orifice of the purifier. The pressure of the steam escaping from
these tubes, independently of the rate of working effectually prevents the water
mixed with the steam escaping from these tubes and the water flowing in the lower
part of the purifier from overflowing into the upper ends of the tubes and passing
down into the elements of the generator.
The feed water being thus compelled to flow along the bottom of the purifier is
energetically agitated by the successive currents of steam escaping from beneath
the dome at the side of each steam supply tube. This water arrives at the return
pipe mixed with the water carried over by the steam proceeding from the elements
of the generator and with the salts precipitated which would otherwise be liable to
form incrustations. The water then passes through the depositing apparatus or
vessel where the greater part of the pulverulent calcareous salts are deposited after
which it enters the feed collector whence it is distributed to the elements of the
generator under the action of the pressure exerted by the column of water in
the return pipe the said column having the effect of producing the forced circulation
in all the elements.
The cycle of circulation is thus completed and no part of the feed water is
permitted to enter the elements except at their lower part and no part of the water
can escape the energetic stirring or the heating to which the whole of the water
requires to be subjected in order to effect the precipitation of the salts. This
precipitation takes place when the pressure of the steam corresponds to a temperature
of about 170 degrees centigrade.
And in order that the said invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the
several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure of the accompanying drawings represents an apparatus constructed
according to this invention in section on the line X. X. X. X. Figure 2.
Figure 2 represents the apparatus in longitudinal section on the line Y. Y. Y.
Y. Y. Y. Figure 1.
Figure 3 represents the apparatus in section on the line Z Z Figure 2, the
transverse partition plates L being removed on the left hand side of the figure
in order to expose the corresponding plates M at the farther end of the apparatus.
Figure 4 represents the apparatus in section on the line U U Figure 2 the
plates M on the left hand of the figure being likewise removed in order to expose
the plates L.
Figure 5 (corresponding with Figure 2) represents the apparatus in horizontal
section on the line V V Figure 1 the section through the dome being taken on the
line V V₁ Figure 2.
This apparatus is constructed with a cylindrical body closed at the right hand
end in Figures 2 & 5 by a plate or cover a provided with a hand hole closed by a
tight fitting cover and supporting a feed injector K. The left hand end of the
cylinder is closed by a plate a' provided with an outlet orifice a, connected with a
return pipe and provided with a small hand hole a² Figure 2. B B are the tubes
through which the steam enters the purifier. These tubes are screwed into the

page_text: under side of the purifier and into a strengthening plate 6 and project into the
interior so that their upper ends are on a level with the centre of the outlet
orifice a.
C is a steam dome placed over the tubes B. This dome which completely
encloses the said tubes is divided longitudinally by a central partition C¹ and is
divided transversely by transverse plates c arranged between the steam inlet tubes B
as represented in Figs. 2 & 5.
The lower edges of the longitudinal sides of the dome C are formed with
notches or angular openings c for the escape of the steam. These notches are
situated below the level of the underside of the outlet orifice a, and are con-
sequently always covered by water even when the quantity of water injected into
the apparatus is very small and only a very small quantity of feed water is flowing
through the apparatus. Consequently the steam never escapes from the dome C
except by passing through a body of water and thereby agitating this water and
heating it if its temperature is not already the same as that of the steam.. The
dome is supported upon the strengthening plate 6 by means of bent plates c³
Figures 1 & 4. The longitudinal partition C' is provided with triangular
openings situated above the tubes B and extends downwards nearly to the
plate 6. This partition C' is provided for the purpose of preventing all the steam
from escaping on one side of the dome when the apparatus is tilted laterally (in
which case the water being thrown to the other side would be liable to be
insufficiently heated) owing to the rolling of the ship when the apparatus is com-
bined with a marine boiler for example. In like manner the transverse plates e
prevent the steam from flowing to either end of the dome when the apparatus is
tilted end wise owing to the pitching of the vessel. The partition is prolonged
at the left hand end of the dome as represented in Figures 2 & 5 for the purpose
of preventing sudden lateral displacement of the water in this part of the
apparatus resulting from the rolling motion of the vessel and equalizing the rate of
flow towards the orifice a.
D is the first horizontal partition employed for drying the steam being provided
at its edges with notches or combs d. Underneath this partition are fixed angle
irons d' forming between them a series of steam chambers corresponding with the
steam inlet tubes B, six only of the latter being shewn in the drawing. The two
steam inlet tubes at each end are not provided with separate chambers but corre-
spond with a single chamber provided at each end of the apparatus on account of
the smaller quantity of steam supplied by these tubes. This arrangement is
provided for the purpose of distributing the steam escaping from the tubes
throughout the whole extent of the circuits or passages through which it has to
flow in order to separate it from the water.
E is a second drying partition provided with combs e & F is a third drying
partition provided with combs f. The three partitions D. E. F. are connected
together by angle irons 1 & 2 and by partitions 3 which support them at the
required distance apart. The central plates or partitions 3 divide the spaces
between the horizontal partitions into two passages.
g
G (Figures 1 & 2) is a steam chamber to which steam is admitted through
small orifices 9 after passing combs provided at 4 & 5. Angle irons or stays 6 & 6¹
are provided in the interior of the chamber G for the purpose of enabling it to
resist the pressure of the steam acting on the lower side of the said chamber
owing to the difference existing between the pressure of the steam in the purifier
and the pressure of the steam in the chamber G. The central angle iron has the
effect of distributing the supply of steam from the orifices g situated near the centre
of the length of the purifier from passing directly to the outlet orifice H. The
steam pipe is connected to the orifice H by means of bolts h.
L L (Figures 2. 3 & 4) represent a transverse partition at the right hand end of
the purifier. This partition is made in three parts consisting of two side plates L
attached to angle irons 7 and one middle plate L' attached to the former by
bolts 8. The plate L' can be removed through the large hand hole in the end

page_text: plate a for the purpose of affording access to the interior of the steam passages
and the steam dome.
1 (Figures 2. 3 & 5) is a screen plate placed in front of the first tube B on the
right hand on the lower part of the purifier in order to arrest the deposits of
carbonate of lime formed in the injection chamber k and which become detached
from time to time. These deposits being arrested by the screen / are prevented
from getting under the steam dome where they would otherwise be liable to
interfere with the free circulation of the steam.
M M (Figures 2. 3 & 4) represent a transverse partition at the left hand end
of the purifier. This partition shuts off the space at the outlet end of the purifier
from the passage in which the steam is caused to circulate on its way to the
chamber G. This partition is made in two parts consisting of a fixed plate M
attached to angle irons 10 and supported upon angle irons 11 and a plate M¹
which is removable being attached to the ends of the steam drying partitions and
being introduced along with the latter. This plate M' bears against the upper
plate M and against the angle irons 11. A wide opening is provided below the
partition M in order to afford free access for the water to the orifice a.
The feed water is introduced into the purifying apparatus through the injector K
Figure 2 and is projected into the interior of a chainberk in which the jet is broken
up and scattered so as to present a large surface of contact with the steam. This
is the first period of the heating of the feed water which is generally sufficient to
cause the precipitation of the carbonate of lime which it contains.
The feed water falls to the bottom of the purifier and passes into the compart-
ment containing the steam dome C. It passes through the purifier from one end
to the other on each side of the steam dome passing the series of tubes B in
succession.
The steam supplied by these tubes and which is blown up through the notches or
angular openings c in the vertical sides of the dome C and on both sides of the
said dome, agitates this feed water which is moreover mixed with the water carried
over by the steam into the purifier. The temperature of the feed water becomes
gradually heated by each steam pipe in succession and when the water reaches
the left hand end of the purifier (Figure 2) its temperature is the same as that of
the steam. This is the second period of heating the feed water and by far the most
important; the high temperature to which this water is raised produces the
precipitation of the sulphate of lime.
The sulphate of lime being precipitated in a pulverulent condition is carried
along by the water to the outlet orifice a' when it passes into the depositing
chamber in which the greater part is deposited.
When the feed water is evaporated by contact with the generating tubes the
sulphate of lime which it may leave in these tubes not being in a crystallizable
condition does not form any adhesive deposit or incrustation on the said tubes.
The steam which is blown up through the angular openings or notches c¹ of the
steam dome and which passes through and agitates the body of water flowing
through the purifier rises vertically until it comes in contact with the horizontal
partition D on each side of the steam dome C. It flows under the partition D to
the right and to the left and escapes through the notches or combs formed at the
edges of the said partition and which retain the greater part of the water with
which the steam is charged.
The steam then changing its direction flows along the passages formed_by
the partitions D and E at the end of which there are provided combs e.
The
water which by reason of its inertia is separated from the steam when the
latter changes its direction is projected against the partition D and flows along
the latter.
The steam passes between the comb teeth e and again changing its direction
enters the passages formed by the partitions E and F. The water being stopped
by the combs drips off from the points of the comb teeth and falls on to the
partition D and the water which is projected against the central partition 3

page_text: trickles down this partition and likewise falls on to the partition D. All this water
flows over the upper surface of the partition D and drips off the points of the
combs where it is out of the reach of the current of steam.
In passing the combs f in order to reach the upper side of the partition F the
steam undergoes further drying by contact with this partition and with the combs
formed thereon; the resulting water dripping from the points of the comb fout
of the reach of the current of steam falls on to the partition E and descends to
the lower part of the purifier through passages formed on each side between an
extension of the partition E and the side of the purifier. The water which by
reason of its inertia is separated from the steam when the latter changes its
direction is thrown against the side of the purifier and trickles down the same.
The steam lastly comes in contact with the combs 4 and 5 by which the drying
is completed. The water collected on these combs drips from the points of the
comb teeth on to the back of the partition F; it flows over this partition and finally
drips off the combs fat the edges of the latter.
The steam being now perfectly dried passes through the orifices g (Figures 1
and 2) into the steam chamber G herein before referred to.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. An apparatus for heating and purifying feed water and drying steam in which
the steam inlet tubes are covered by a dome which compels the steam to forcibly
agitate the feed water independently of the quantity of water passing through the
apparatus substantially as herein before described and illustrated in the accompanying
drawings.
2. An apparatus for heating and purifying feed water and drying steam com-
prising a triple system or combination of drying partitions provided with combs
or notched edges which retain or intercept the water carried over with the
steam substantially as hereinbefore described with reference to the accompanying
drawings.
3. An apparatus for heating and purifying feed water and drying steam
constructed with steam inlet tubes, such as B, a dome such as C covering the same
and an orifice for the escape of the feed water having their relative positions
so adjusted that the water admitted at one end of the apparatus is caused
to escape at the other end without entering the steam inlet tubes substantially as
hereinbefore described with reference to the accompanying drawings.
4. In an apparatus for heating and purifying feed water and drying steam the
combination of a steam dome covering the steam inlet tube and descending below
the orifice for the escape of the water with a number of steam drying partitions
provided with combs or notched edges substantially as hereinbefore described with
reference to the accompanying drawings.
5. The arrangements and combinations of parts constituting the improved
apparatus for heating and purifying feed water and drying steam substantially as
bereinbefore described with reference to the accompanying drawings.
Dated this 21st day of June 1892.
J. H. JOHNSON & Co.,
Agents.