AN IMPROVED REFRIGERATING AND HEATING APPARATUS
Year: 1878

page_text: LETTERS PATENT to Carl Pieper, of Dresden and Berlin, for the Invention
of "AN IMPROVED REFRIGERATING AND HEATING APPARATUS.” A communi-
cation from Dr. Albrecht Drache, of Erfurt, Prussia.
Scaler the 17th September 1878, and dated the 19th March 1878.
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office
of the Commissioners of Patents on the 19th March 1878.
CARL PIEPER, of Dresden and Berlin. "AN IMPROVED REFRIGERATING AND
HEATING APPARATUS." A communication from Dr. Albrecht Drache, of Erfurt,
Prussia.
This Invention relates to a refrigerating and heating apparatus for liquids,
vapours, gases, and air, in which the substance to be cooled or heated is spread out
in layers, and maintained separate from layers of the cooling or heating medium
by plates, which may be flat or provided with series of protuberances.
Fig. 1 of the annexed Drawing represents this apparatus with the end part B
and the top removed; Fig. 2 shows the end part B; and Fig. 3 an enlarged view
of the plates D. These plates are provided at the two lateral edges on the upper,
and also on the under side, with ledges d, d, and at the ends with a number of
short ledge pieces e and f. The latter are arranged in the manner shown in Fig. 3,
so that a ledge piece e on the top of any plate is opposite to a space between
two lodge pieces f on the under side, and that the ends of the upper ledges
overlap those of the lower ones. A series of such plates being placed one upon
the other the spaces s, t, u, v, &c., are formed between them, each space having a
number of openings at either end, which alternate in any two contiguous spaces,
so that the openings of the vertical rows 1, 3, 5, 7, &c., communicate with the
spaces 8, u, w, &c., while those of the rows 2, 4, 6, 8, &c., communicate with the
intermediate spaces t, v, x, &c.
The liquid or gas, &c., to be heated or cooled is introduced by the tube I, Fig. 2,
into the chamber L of the end or channel part B (shown detached from the
apparatus), and is discharged by tube I¹.

page_text: The heating or cooling medium enters at H¹ into a chamber similar to the
chamber K, and flows off at H.
The currents of the liquids or either of them may however be reversed, or the
liquid, &c., to be heated or cooled may pass into and out of the apparatus by
the tubes H and H', and the said medium by the tubes I¹ and I.
The chamber L communicates with a number of vertical channels 1, 3, 5, 7, &c.,
and the chamber K with the channels 2, 4, 6, 8, &c., lying between the former in
the manner shown by Fig. 2. The edge surfaces of the partition walls between
the said channels correspond with the reciprocally overlapping parts of all the
ledge pieces e and f, so that when the part B is screwed to the part A the
channels 1, 3, 5, 7, &c., communicate by the openings of the rows 1, 3, 5, 7, &c.,
with the alternating spaces s, u, w, &c., and the channels 2, 4, 6, 8, &c., by the
openings of the rows 2, 4, 6, 8, &c., with the alternating spaces t, v, x, &c., which
are intermediate to the former. The two liquids, gases, &c., entering into the
apparatus will thus be distributed in alternate layers, being kept separated by the
intervening plates.
For the purpose of making the joints tight, sheets of india-rubber suitably per-
forated are introduced between the ends of the plates D and the parts B & B,
and other solid sheets laterally between the edges of the said plates and the vertical
adjustable plates E.
The whole tier of plates D is pressed together by a covering plate (not shown in
the Drawing) which is bolted to the casing A.
The plates D may be flat, or they may have series of pyramidal or otherwise
shaped protuberances pressed into them, which, bearing with their apexes on cach
other, prevent the plates from bending or collapsing in case the pressures of the
two liquids are different.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Pieper in the Great Seal Patent Office on the 19th September
1878.
CARL PIEPER, of Dresden, in the Kingdom of Saxony, Civil Engineer. "IM-
PROVED REFRIGERATING AND HEATING APPARATUS." (A communication from
Dr. Albrecht Drache, of Erfurt, German Empire, Prussia.)
This Invention relates to a refrigerating and -heating apparatus for liquids,
vapours, gases, and air, in which the substance to be cooled or heated is spread out
in layers, and maintained separate from layers of the cooling or heating medium
by plates, which may be flat or provided with series of protuberances pressed into
them.
On the annexed two Sheets of Drawings this apparatus is represented in different
views.
Fig. 1 is a perspective outside view with front wall of part B broken away;
Fig. 2, a view of the main or central part; and Fig. 3, a view of the end or channel
part B¹.
The Figures 4 to 9 represent details, and Figs. 10-15 modifications of the
apparatus.
Within a casing A the plates D, shown in detail in Figs. 4 to 7, are arranged
above each other. These plates are provided at the two lateral edges on the upper
and also on the under side with ledges d, d, and at the ends with a number of
short ledge pieces e and The latter are arranged in the manner shown in Figs. 4
and 5, so that a ledge piece e on the top of any plate D is opposite to a space
between two ledge pieces on the under side, and that the ends of the upper ledge
pieces overlap those of the lower ones. A number of such plates being placed one
upon the other the spaces s, t, u, v, &c, are formed between them, each space being
closed at the sides, whilst it has a number of openings at either end, which alternate
in any two contiguous spaces, so that the openings of the vertical rows 1, 3, 5, 7, &c.
(Figs. 2 and 5), communicate with the spaces 8, u, w, &c., while those of the rows 2,
4, 6, 8, &c., communicate with the intermediate spaces t, v, x, &c.
The liquid or gas, &c., to be heated or cooled is introduced by the tube I, Fig. 1,
and is discharged by tube I.
The heating or cooling medium enters by the tube H' at the opposite end, and
flows off at H.
The currents of the liquids, or either of them, inay however be reversed, or the
liquids, &c., to be heated or cooled may pass into and out of the apparatus by the
tubes H and H', and the said medium by the tubes I' and I.
The tube I leads into a chamber L, Fig. 1, in the channel part B, which corre-
sponds to chamber L' in B', Fig. 3. Either of these chambers communicates with
a number of vertical channels 1, 3, 5, 7, &c. In a similar manner either of the
chambers K and K¹, Figs. 1 and 3, communicates with the channels 2, 4, 6, 8, &c.,
lying between the former. The edge surfaces of the partition walls between the
said channels correspond with the reciprocally overlapping parts of all the ledge
pieces e and f, so that when the part B is screwed to the part A the channels 1, 3,
5, 7, &c., communicate by the openings of the rows 1, 3, 5, 7, &c., with the spaces 8,
u, w, &c., and the channels 2, 4, 6, 8, &c., by the openings of the rows 2, 4, 6, 8, &c.,
with the spaces t, v, x, etc., which are intermediate to the former. The two liquids,
gases, &c., entering into the apparatus will thus be distributed in alternate layers,
being kept separated by the intervening plates.
The whole tier of plates D is pressed together by a strong covering plate C
bolted to the casing A.
For the purpose of making tight the joints between the ledge pieces e and f, and
also between these and the corresponding surfaces of the parts B and B', sheets of
india-rubber suitably perforated may be applied. It is however more convenient

page_text: to use a packing plate F, Fig. 8 and 9, composed of a sheet of metal lined on both
sides with india-rubber.
The metal and the lining fixed to one side must be perforated, so as to correspond
to the openings between the plates D (see Fig. 8), while the lining on the other
side may be provided with slits corresponding to the channels in the parts B and
B¹ (see Fig. 9).
.
For closing the joints between the lateral ledges d of the plates D a solid sheet
of india-rubber is introduced on either side between the tier of plates D and a
plate E; or the india-rubber may be permanently fixed to this plate, which can be
pressed against the plates D by the screws g.
If the pressures of the two liquids, gases, &c., within the apparatus are equal, or
nearly so, the plates D may be flat; but if there is a material difference between
these pressures the plates must be stiffened by corrugations or otherwise, or they
must reciprocally support each other. For this purpose it is preferable to press or
emboss into the series of pyramidal or otherwise shaped protuberances, which
bearing with their apexes on the protuberances of the contiguous plates prevent the
plates from bending or collapsing. Plates of this design are shown by Figures 4
and 5 in perspective view, and in Figures 6 and 7 in sections, according to the
lines m, n, and m³, n¹, respectively. This arrangement of the plates tends also to
improve the circulation of the two liquids, &c., and to promote the transmission of
heat from the one to the other.
For the purpose of properly adjusting the plates D in the casing A, and of
making their ends flush with each other, straight plates or bars serving as templates
or guides are screwed to the casing, and the plates E having been drawn back
the plates D are regularly piled upon each other, and thereupon pressed together
by bolting down the covering plate C. The end parts B and B' are subsequently
attached, and the plates E tightened against the plates D.
The described apparatus presents a large heating surface in comparison to the
space which it occupies; it may casily be taken to pieces for cleaning it, and it can
be manufactured at a comparatively low cost.
The apparatus may be applied for the heating and ventilation of rooms, as
surface condenser for steam engines, for dephlegmating and condensing in distilleries,
and for other similar purposes requiring a heating or cooling of liquids, vapours,
gases, and air.
If it is desired to use the described apparatus for heating or cooling liquids
which corrode metals, or upon which metals would have a prejudicial influence,
such as acids, solutions of other metals, &c., the same may be made of glass.
For the purpose of facilitating the construction in this case the ledges d, c, and f
of the plates D may be left away, for if the latter are made sufficiently thick so as
not to cut into the india-rubber packing of the plates E and F, tight joints may be
obtained without the ledges. The proper distribution of the liquids is in this
case caused by the channel parts B, B', and the perforated plates F only, which
nay both also be made of glass, the latter being lined by india-rubber, as described
above.
On Sheet 2 of the annexed Drawings a modification of the described apparatus
is represented, in which each pair of contiguous plates D¹, Figs. 10 and 11, is
made out of one piece, the original, either flat or embossed plate, being bent along
its center line until the edges parallel with this line touch each other. Those
edges h, i, Fig. 11 and 12, are or may be thereupon brazed or soldered together.
If the plates are embossed, as has been described above, this must be dono in such
a manner that the tops of the truncated pyramids or other embossments of one
half plate come fairly into contact with those of the other half, and moreover a
strip in the centre of the plate and the two lateral edges must remain flat, as
will easily be understood. A number of such double plates are placed one upon
the other in a casing A, Fig. 10, similar to the one described above, and having
cover C and packing plates F', but they do not require any packing at the sides,
as in the arrangement of Sheet 1.

page_text: In case the temperature of either of the two liquids or gases passing the appa-
ratus is sufficiently high as to be liable to damage an india-rubber lining of the
packing plates F, Fig. 8 and 9, or F1, Fig. 10, between the channel parts B or B¹
and the plates D respectively, the casing A, these packing plates may be made of
lead, tin, or other suitable soft metal, or of iron lined with such metal.
For obtaining a perfect fit in this case the apparatus is completely put together
with exception of the tubular pieces I, 1', H, and H', and is hereafter brought end-
wise under a hydraulic or other powerful press for the purpose of pressing the
edges of the plates D' of the partition walls l, &c, into the metal, out of which
the packing plate F or its lining is made. Hereupon all the screws are drawn
tight, and the tubular parts screwed on.
In any case the perforations of the plate F¹ must correspond in such a manner
with the openings at the ends of the double plates D', Fig. 10 and 11, that the two
liquids are properly distributed on the principle elucidated above.
It need barely be mentioned that the shape of the openings simply results from
the plates being embossed as described, and supposed to be cut off through the
centre of a row of pyramids, in the same manner as shown by Fig. 6.
The casing A has large openings at the sides, which are closed by the fiat
covers N, Figs. 10 and 15, but these covers need only be made tight at their edges
without bearing on the edges of the double plates or flat tubes D', as will be
understood without further explanation. The cover C must of course also be pro-
vided with suitable packing at its edges.
If the long edges h', ', of the described double plates are not brazed together, as
supposed with regard to the plates D, Fig. 13, they require a packing plate lined
with india-rubber, &c., corresponding to plate E of Fig. 2, while the opposite side of
the casing may have the covers N of Figs. 10 and 15.
In either of the two described modifications the spaces between the double plates
or flat tubes D' or D¹¹ may be cleaned after the covers N on both sides, respectively
on one side, have been removed. This cleaning may be done lengthwise and across
by a jet of water, or by a brush or scraper, which can be introduced between any
pair of contiguous rows of pyramids, the spaces between them forming as it were
straight channels, a section along which is represented by Fig. 7.
The packing plate F¹ may be protected against coming in contact with very hot
gases or liquids by applying the double plates D", Fig. 12. The edges at the
ends of these plates are straight and bent outward, so as to be flush with the tops
of the described pyramids or other embossments. In consequence, these edges of
the contiguous double plates will touch each other upon their whole length, or
nearly so (see also Fig. 12b, which is a section on line qu, qu¹, qu", Fig. 12a).
The packing plate F¹ is provided with horizontal rows of holes having solid strips
between them for closing the joints between the plates D". The end parts B & B¹
have no separating channels, and consist each of but one chamber provided with a
single branch pipe for the inlet or outlet of the liquid, &c., of low temperature. The
ribs in the parts B, B', are however by preference maintained for pressing the
plate F¹ more securely against the plates D¹¹.
For the inlet and the discharge of the hot liquid or gas the hollow or recessed
covers O, Fig. 14, provided with tubes have to be put into the place of the
covers N, Fig. 10 & 15. With this arrangement the two liquids certainly cannot
pass the apparatus in contrary directions, but their currents cross each other.
Having thus described the nature and object of this Invention, as communicated
to me by the inventor, I claim as new and essential features of the said improved
refrigerating and heating apparatus,―
1. The plates D, Fig. 2 and 4-7, having the ledges d and the ledge pieces e, f,
in combination with a casing A, and with the channel parts B and B having the
channels 1, 3, 5, 7, &c., leading from the tube I or 1' into the spaces 8, u, w, &c.,
between the plates D and the channels 2, 4, 6, 8, &c., leading from the tube H or
H' into the spaces t, v, x, &c., between the plates D, substantially as and for the
purpose specified.

page_text: 2. In combination with the plates D having the ledge picces e, f, and with the
channel part B or B₁ the perforated plate F, Figs. 8 and 9, made of metal and
india-rubber, substantially as and for the purpose set forth.
3. In combination with the described refrigerating and heating apparatus the
plates D provided with pyramidal or otherwise shaped protuberances, substantially
as specified and for the purpose set forth.
4. The double plates or flat tubes D', Fig. 11, in combination with the casing A
provided with the lateral covers N, as-specified and for the purpose set forth.
5. The double plates or flat tubes D1, Fig. 13, in combination with a casing
provided on one side with covers N, on the other with a packing plate E, Fig. 2,
as and for the purpose specified.
6. The double plates or flat tubes D", Fig. 12a & 12b, in combination with a
casing provided with the covers O, Fig. 14, as specified, and for the purpose set
forth.
7. The perforated packing plate F', Fig. 10, consisting of metal, or of a com-
bination of metals, together with the double plates or flat tubes D', D¹¹, or 1,
Figs. 11-13, as and for the purpose described.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand
and seal, this Twentieth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
CARL PIEPER. (L.S.)