Improvements in Refrigerating Machinery.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Refrigerating Machinery.
I, WILLIAM MCKEEGAN, of 42 Lambton Quay in the City of Wellington, in
the Colony of New Zealand, Engineer, 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 :―
My invention relates more especially to improvements in refrigerating machinery
by which cold air is produced, discharged into, and circulated in refrigerating
chambers, as is the case in such machines as those patented by Bell & Coleman,
Haslam, and others.
The objects of my invention are to cool the air in the cold chamber in a more
efficient manner so that an even temperature may be readily preserved, the deposit
of snow in the machinery reduced, and such deposit transferred to a part of the
apparatus where it is easily disposed of thus producing economy of fuel and great
facility in regulating and working the whole arrangement.
I attain these objects by apparatus illustrated in the accompanying drawings
in which,
-
Figure 1 is a sectional plan of the principal part of my improved apparatus
which I call the cooler.
Figure 2 is a longitudinal section of the same, and
Figure 3 is an end view of the same.
Similar letters refer to similar parts in all the figures.
The
(a) are the outer walls of an air tight chamber formed (by preference) of wood
planking and fitted with inspection doors (a¹), inlet ports (b) for the introduction of
the cold air from the refrigerating machine proper and outlet pipe (c).
refrigerating or cold air machine is of the usual type of compressed air refrigerating
machinery, the outlet pipe (c) being connected with the inlet to the air pump, and
the inlet pipe (6) connected with the expansion cylinder of the said air refrigerating
machinery.
I prefer this chamber together with its connecting pipes to be covered with
suitable non-conducting material.
(d) are tube plates fixed within the air tight chamber and leaving spaces (d¹) on
either side between the said plates and the walls (a).
(t) are tubes fitted into holes made in the tube plates.
(d) in a similar manner to the tubes of an ordinary steam boiler so as to be
thoroughly air tight and thus forming a communication between the spaces (d) and
rendering the same air tight and leaving an air tight chamber (d2) between the said
plates.
(u) are baffle plates for a purpose to be hereinafter described.
(s) are also baffle plates for a purpose to be hereinafter described.
(e) is an inlet pipe into the chamber (d²).
(f) is an outlet pipe from the same.
(g) are safety valves to prevent any undue pressure in the chamber (d²).
(h) are pipes fitted with cocks (h¹) (2) & (3) to supply hot air or steam to each
division of the chamber (d2) so as to clear away the deposits when desired.
(w) are waste pipes for running off the same when melted.
It will thus be seen that I construct an inner chamber (d2) having inlet (e) and
outlet (f) and two outer spaces or chambers (d') having an inlet (b) and outlet (c);
to the inlet (6) I fix the pipe leading from the expansion air cylinder of an ordinary
air refrigerating machine which propels the cold air through the tubes (t) back-
wards and forwards as shewn by the arrows several times according to the number

page_text: of the baffle plates (3) thus cooling the whole chamber and returning the air at a
higher temperature back to the air pump through the outlet (c). By these means
1 circulate, comparatively dry air through the apparatus and diminish to a minimum
the moisture and collection of snow which forms such a troublesome feature and
obstruction in air refrigerating machinery, and 1 can also thus very readily regulate
the required temperature with a minimum expenditure of fuel.
To apply the before mentioned apparatus to the chamber containing the goods
and articles to be preserved I place the said apparatus within or near to any
ordinary cool or refrigerating chamber, and by a fan or other suitable apparatus I
circulate the cold air through the inlet pipe (e) and chamber (2) over and under
the baffle plates (u) and the tubes (t) and out at the outlet (f) which returns it
again to the refrigerating or cooling chamber, after being cooled, and through the
return passage (f). By this simple circulation the temperature can be readily
equalised and the moisture taken up by the circulating air will be deposited on the
cold surface of the tubes (t) from which it can be easily removed by a draught of
warmer air or steam blown over the surface of the tubes, the apparatus being for
the time cut off from the refrigerating chamber proper.
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. In dry air refrigerating machinery the introduction into or in contact with the
ordinary refrigerating chamber of an apparatus having a chamber composed of
walls such as (a) divided by tube plates such as (d) and carrying tubes such as (t)
so as to form an inner chamber such as (²) or mechanical equivalents of the
same as and for the purposes substantially as described herein and illustrated.
2. In dry air refrigerating machinery circulating the cold air in a separate
chamber or cooler and exposing or circulating the air of the freezing or cooling
chamber proper around the said separate chamber or cooler substantially as set
forth.
Dated this 19th day of August 1893.