Improvements in Means for Heating by Steam Feed Water and other Liquids.
Year: 1894

page_text: Date of Application, 5th Feb., 1894-Accepted, 28th Apr.,
1394
COMPLETE DIECIFICATION.
Improvements in Means for Heating by Steam Feed Water and
other Liquids.
I, HUGO KOHL, Engineer, of Euskirchen in the Province of Rhineland, Prussia,
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 :-
The heater is drawn in
Fig. 1. in longitudinal section, while
Fig. 2 and 3 shew different parts in front-view, and
Fig. 4 a modification of the apparatus for a special purpose in longitudinal
section.
The apparatus consists of three chief parts, the outer pot A, the inner tube B
and the casing C, situated between the two. In the arrangement as in Fig. 1 these
three parts are fitted on a common bottom-plate D, which in its turn rests on a
raised support, either as in the drawing, a cast-iron ring E, or masonry, or wooden
blocks or wrought iron-feet, or a kind of tripod. The parts B and C are
connected with each other at the top by an air-tight ring F. Indeed, all surfaces,
where A B C D and F touch each other are well turned and fit closely together.
The inner tube B-in Fig. 2 drawn in front-view-is provided on its outer surface
with two screw-threads a and a₁ running between each other and terminating at
the top below the end-flange b. diametrically opposite each other, so that the spiral-
shaped passages cc, formed between the two screw-threads are connected at the top
by a ring-passage d. The lower ends of the passages c c₁ are carried vertically
downwards diametrically opposite each other and have their outlet through the
plate D into pipes that are placed there. The casing C lies close on the screw-
threads a a1.
Thus in the interior of the apparatus there are two spaces formed,
separated from each other, namely between plate D, tube B, casing C and ring F,
space 1, forming two passages winding in the shape of a screw and running between
each other, but connected at the top with each other, and between plate D and
tube B a cylindrical space II, which is connected by means of the free space III,
remaining between ring F and the bottom of the pot A. with the other ring-shaped
space N, formed between pot A and casing C. Water or steam can be conducted,
according as desired, through space I, when steam or water correspondingly passes
through the other spaces.
In Fig. 1 it is taken for granted that the water passes through space I and is
heated by the steam circulating in the other space. The cold water enters by the
tube e into the spiral-shaped passage c, ascends in it through the ring-passage d,
and then descends again in the spiral-shaped passage c₁ and flows out in a heated
state through the tube e₁. The steam enters by an upright tube in the centre of
the plate D into the space II, ascends in it through the space III into the space N
and descends in the latter, till it finds an outlet at g. In order now, on the one
hand, to carry away the waste-water, formed more especially in the space III by
the contact of the hot steam with the cold water, and on the other hand to better
press the steam against the walls of the tube B and to force it to completely give
off its heat by pressing against it on as long a way as possible, there is another
tube G placed from above in the space II, which is especially drawn in Fig. 3.
This tube has on its circumference a spiral-shaped groove h, lying with its exterior
edge on the tube B. Along the groove in the tube G. there are fine holes i made,
which allow the waste water, collected in the groove to enter into the interior of
the tube. The tube is drawn out into a narrow point k, which passes into the

page_text: steam-inlet-pipe f, and reaches through its lower wall so as to be able to be
connected here with a tube for carrying away the waste water. The steam, that
has entered through, is thus forced to ascend, following the thread of the
groove h and thus passing round the tube G and in doing this, it thoroughly
heats the walls of the tube B in all its parts, and gives off its waste water to the
groove and through the holes i to the tube G, whence it flows off below.
Fig. 4 shews the application of the apparatus with a slight modification, to the
heating of fluids by exhaust steam, which are not continuously to flow through, but
are to be heated for a lengthened time in fixed quantities. In this case the juice of
sugar in sugar-refineries is taken as an example. The juice foams to a great extent
and therefore the vessel in question must be open at the top and not quite full and
have a protecting rim to prevent the foaming over. This is attained in Fig. 4 by
the apparatus drawn in Fig. 1 being placed on its head i.e. on the bottom of the
pot A, the plate D taken away and the casing of A being provided with the margin-
ring H, while the inner parts B, and C, connected as before with each other, are
now no longer supported by plate D, but are held suspended by stays, feet or ribs,
as in the drawing, in such a manner in A, that between space II and N the
connecting space III does not disappear. Naturally B and C must now be closely
connected with each other by a ring K at the upper end, where the plate D is now
missing and which was formerly the lower end. But the connexion can also be
made directly by flanges 1, as well above as below, as is shewn in the right-half of
Fig. 4.
In this case, as represented in Fig. 4, the steam entering at e and passing out
at e, goes through space I, while the other spaces of the apparatus are filled with
the fluid (sugar-juice), which is let in above and finally flows out below through a
cock m.
The waste water formed in space I is collected in the ring-space d and
carried from here sideways through the casing of A.
The chief advantage of this heater over the others that exist, is in the double
spiral, which causes the water and the steam to travel a very long way in opposite
directions, thereby effecting the most complete utilization of the heat of the steam,
as well as a very uniform distribution of heat in all parts of the water, the
descending hotter layers of water either pressing between the ascending colder
ones, or the descending colder steam between the ascending hotter steam and
vice versa.
Practical experiments have proved that in such an apparatus the well-water
heated by the exhaust-steam of a steam-engine flowed off in almost a boiling
state.
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. Heater for feed-water, distinguished by the arrangement of a double-
spiral a a, situated on the exterior surface of a tube B, and made tight by the
casing C, which is placed over it in such a manner, that two passages turned like a
screw and running between each other, c c₁, are formed, being connected with each
other at one end by means of a ring-passage d, but forming separate outlets at the
other end.
2. In such heaters the insertion of a tube G in the cylindrical steam-chamber 11
and provided with a spiral-shaped groove h on the outside and fine holes i for the
carrying off of the waste water.
Dated this 25th day of January 18041
For HUGO KOHL,
B. Brockhues.