IMPROVEMENTS IN THE CONSTRUCTION OF BOILERS, CONDENSERS, AND OTHER ANALOGOUS APPARATUS FOR RAISING AND LOWERING THE TEMPERATURE OF FLUIDS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Patrick John Lynam at the Office
of the Commissioners of Patents on the 29th November 1881.
PATRICK JOHN LYNAM, of Raheen, Ballinasloe, in the County of Galway,
Ireland. "IMPROVEMENTS IN THE CONSTRUCTION OF BOILERS, CONDENSERS, AND
OTHER ANALOGOUS APPARATUS FOR RAISING AND LOWERING THE TEMPERATURE
OF FLUIDS."
This Invention consists in improvements in the construction of boilers, con-
densers, and other analogous apparatus in which heat is transferred from one fluid
to another, and is based on the well known principle that the internal thermal
resistance of metals is generally small compared with the external thermal
resistance.
Within the chamber or channel through which the hot fluid passes, and in
some cases also within the chamber or channel through which the cold fluid
passes, I arrange longitudinally a set of thin metallic plates fixed a short distance
apart.
Where the fluids have very different resistances, it is desirable to have one set
of plates only, as for instance, in applying this Invention to boilers I arrange a set
of parallel metallic plates longitudinally within the fire tubes or flues, thereby
dividing the latter into a series of narrow parallel spaces through which the hot
air and products of combustion pass. The said fire tubes or flues are constructed
of any suitable metal and of any desired section, and the parallel plates are
arranged longitudinally across the interior of the same and are connected to each
side. In order to allow of the expansion of such plates, I in some cases divide the
same longitudinally down the centre, or I form them in any suitable and known
manner for preventing the injurious effects of expansion when exposed to heat, and
in some cases to allow of such expansion I make the said plates of less width than
the interior of the fire tube or flue, and attach them alternatively to opposite sides
of the latter. The hot air and products of combustion circulate on both sides of
the plates, and the heat being absorbed by the latter is conducted along the same
to the metal frame or casing of the fire tube or flue, where it is transferred to the
water contained in the boiler.

page_text: In apparatus where it is desirable that more than one set of parallel plates be
employed, such sets of plates must bave sufficient metallic connection to ensure
conduction of heat from one to the other, as will be readily understood from the
following description of the application of this Invention to apparatus for con-
densing steam by cold water. The body of the apparatus consists of a vessel or
receptacle of suitable size, and constructed of brass, iron, or other metal; the said
vessel is divided by two partitions of metal into three watertight and steam tight
chambers. The centre chamber is utilised for the passage of the steam and is
provided with a set of parallel plates arranged in a similar manner to those in the
fire tubes as herein before described. A space is left between the ends of the plates
and the ends of the chamber, so that the steam on entering at one end of the
chamber may be free to pass through the whole of the narrow spaces formed by
the parallel plates, whilst the water resulting from condensation escapes from the
said spaces at the opposite end of the chamber, whence it is conducted by any
suitable means. The cold water is caused to circulate in the opposite direction to
the steam through the side chambers, each of which has arranged therein a set of
parallel plates in a manner similar to that above described, but in all cases the said
plates must be in metallic connection with the metal partition separating their
respective chambers from the steam chamber. It will be found convenient to make
the last mentioned plates of less width than the cold water chambers, so that
whilst they are maintained in the desired position by being attached to the metal
partitions, they do not extend across the whole width of the chambers, thus
allowing of expansion. The cold water enters at one end of the chambers, flows
through the narrow spaces between the plates, and escapes at the opposite ends.
The plates arranged as above described present a large metallic surface to the cold
water and steam. The heat is abstracted from the steam by the plates in the
centre chamber, and is conducted through the metal partitions to the plates in the
side chambers where it is absorbed by the cold water.
In large apparatus the number of chambers may be increased to any extent,
such chambers being arranged in alternation so that a steam chamber will have a
cold water chamber at each side. The ends of the vessel or receptacle are made
removable so as to facilitate the cleansing of the plates and the interior of the
chambers.
The superficial areas of the plates when more than one set is employed are
proportioned to the external thermal resistances of the fluids, and the thickness of
the plates and of their metallic connections is proportioned to the internal thermal
resistance of the metal employed as will be well understood.
Amongst the advantages possessed by boilers and other apparatus constructed in
accordance with this Invention may be mentioned their comparative freedom from
explosion, their great strength and simplicity of construction, whilst at the same
time they are more compact, are of less weight, and possess a greater heating
and cooling surface in a given space than similar apparatus constructed in the
ordinary manner.