Improvements in or appertaining to Treating Frozen Carcases or the like.
Year: 1894

page_text: Date of Application, 18th Oct., 1894
Complete Specification Left, 18th July, 1895-Accepted, 12th Oct.
1895
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Treating Frozen Carcases or
the like.
1.
I, JACOB ATHERTON of Mayfield, Huyton, Liverpool in the County of
Lancaster, Electrical Engineer, do hereby declare the nature of this invention to
be as follows:-
,
This invention has for its object improved means for thawing, and in some
instances for keeping or preserving frozen meat.
'
I hang or place the meat or carcase in a chamber through which warm air is
circulated. This warm air is either dried in its circuit outside the chamber, where.it
may also be heated by passing through a layer or layers of calcium chloride, sulphuric
acid, caustic alkali, or other absorbent of moisture, or these chemicals can be
placed in the chamber itself. The air can be heated in any known manner, and the
amount of heat regulated according to the kind of meat to be treated, and whether
it is simply to be thawed or to be preserved for a considerable time in the thawed
condition. The circulation can be by means of fans or other mechanism, or even
by the actual heating of the air itself. The heat of the chamber containing the
meat can be regulated by external applications or simply by injecting the air by
means of an air injector or pump at the right temperature. In some cases in place
of air, I may use a mixture of carbonic acid, or carbonic oxide, or both, and
nitrogen formed by passing the air through heated carbon, metal, or other suitable
oxidisable material. The heat of this muffle can be used for causing the circulation,
and a desiccating apparatus can be placed in the course of circulation immediately
before the air or gases enter the muffle. If powdered zinc or iron be used in the
muffle, almost pure nitrogen is the result and pure nitrogen from a soda factory or
other source of nitrogen or the gases from a lime kiln.or otlier source of nitrogen
and carbonic acid can be used. In some instances I add an antiseptic gas or may
employ peroxide of hydrogen. In some instances also, I may dip the meat, in
alcohol after or before the process when it is desired to somewhat tan the surface
and colour the fat, colouring matter may be added to the alcohol. if desired. This
portion of the process should be performed in a closed vessel so as to prevent loss
of alcohol. Alcohol can also be employed to absorb the moisture.
Where plenty of time can be employed for the thawing I may very greatly
increase the size of the chambers so as to form them into warehouses, and use air or
gas very slightly above freezing point, as with some meats it is found that the
slower the thawing is effected the better the meat keeps afterwards and so long
as a neutral or antiseptic gas like carbonic acid, carbonic oxide, or even nitrogen
be employed, or even dry air. not much above freezing point be employed the
meat can be preserved for a very considerable time. One plan of operation
which I have already tried and find very efficacious is to use a partial vacuum.
This absorbs the moisture, and at the same time the heat radiating from the
surface of the chamber thaws the meat. Where carbonic acid or valuable. gas
is used I prefer to exhaust the chamber and then. pass in the gas and when the
gas becomes loaded with moisture it is passed through the desiccator through
the heating apparatus if such be employed and returned again to the chamber,
827

page_text: when the process is accomplished it is pumped out and air let in preparatory to
the door being opened.
Dated the 17th day of October 1894.
WM P. THOMPSON & Co.,
Of 6 Lord Street, Liverpool, Patent Agents for the Applicant..
Improvements in or appertaining. to Treating Frozen Carcases or
the like.
I, JACOB ATHERTON, of Mayfield, Huyton, Liverpool, in, the County of
Lancaster, Electrical Engineer, 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:-
This invention has for its object improved means for thawing and in some
instances for keeping or preserving frozen meat.
In order to thaw the meat that has been preserved by freezing in such a way as
to prevent discolouration, deterioration or both in quality, I hang or place it in a
chamber through which is circulated an antiseptic gas (preferably mixed with air)
in a dry and heated state. The gases are dried outside the chamber or drying
agents are placed within. I may also avail myself of the aid of a partial vacuum
in the chamber which will have a like drying effect. The most suitable gases. are
carbonic acid (CO,) and carbonic monoxide (CO) or mixtures of these with, air
or-nitrogen. I shall now proceed to describe the process of using, these gases-
according to my invention so as to thaw frozen meat in the most efficient manner.
The meat is hung in a closed chamber preferably in the form of whole carcases
of the smaller animals such as sheep or half.or quarter carcases of beef. I prefer
that the walls of the chamber should be capable of resisting, external or internal
pressure; as it is sometimes of advantage to have the pressure within the chamber.
above or below the atmospheric pressure, but this is not essential. The meat
must be hung or placed so that there is free circulation round it. I then cause dry
heated carbonic acid (CO,) or a mixture of carbonic acid (CO2) and air or nitrogen
to pass into the chamber. This I do by arranging a circulation of such gas,
making it pass by means of a fan or otherwise from the gasholder or generator in
which it is stored or produced through sulphuric acid or calcium chloride or
equivalent drying: material. When the pressure in the chamber is as high as
desirable arrangements must be made to allow the surplus air in the chamber to
escape. It will generally be found to be convenient to do this by means of an exit
pipe communicating with the closed channel through which the gas passes to the
drying chamber, as by this means a continuous circulation of dry heated air and
carbonic acid (CO,) will be maintained. It is easy with this arrangement to secure
the presence of any desired percentage of carbonic acid (CO2) in the chamber by
regulating the pressure in the gasholder or generating chamber or opening, or
closing cocks that connect it with the circulation.
We find a suitable percentage of carbonic acid (CO,) for ordinary works to be
25 to 50 per cent. The temperature should be about 80° to 120° Fabr. if the
thawing is to be effected in 6 to 8 hours for mutton and 16 to 20 hours for beef.
These figures will be sufficient guide in practice, but of course they will vary a
little according to the manner in which the original freezing and subsequent
preserving by cold has been carried out.
The carbonic acid (CO,) in proportions such as these of which I have been
speaking will be found to have a very marked antiseptic effect. Other antiseptic

page_text: ases may be used, but no one is so convenient and gives such good results for
main process of thawing as carbonic acid (CO,).
When the thawing has proceeded for from one third to three quarters of the full
ime required I admit into the chamber a quantity of carbonic monoxide gas (CO).
either by means of the circulation channels or otherwise. The proportion of
carbonic monoxide (CO) as compared with air and other gases present should be
about one to five per cent. This gas is also antiseptic in its action and it moreover
possesses a special power of giving to the meat a good colour.
It will be obvious that the details of this process can be varied in many ways.
Thus means can be taken to lessen the percentage of oxygen in the chamber or by
extracting it from the air used in the circulation or supplying the place of such air
Where plenty of time can be allowed and large
by nitrogen or other suitable gas.
chambers can be provided I may thaw very slowly and thus keep the meat at a
temperature slightly above freezing point for a long time. In such case the air in
the room should be charged with carbonic acid (CO₂) or a mixture of carbonic
acid (CO,) and carbonic monoxide (CO). In the former case the meat should be
subjected to the action of carbonic monoxide (CO) at the end of the process to.
improve its colour. In this modification of my invention it may be convenient to:
dispense with the circulation and apply heat to the room itself. Drying agents.
must then be placed in the chamber and the percentage of antiseptic gases should.
be somewhat higher than when a circulation is used.
Having now particularly described and ascertained the nature of my said'
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The hereindescribed process of thawing frozen meat by the employment of an
antiseptic gas or mixture of gases (preferably in combination with means for
drying the same) substantially as herein-described.
2. The hereindescribed process of thawing frozen meat by means of a circulation
of air or gas containing carbonic acid or carbonic monoxide (CO) or other anti-
septic gas in suitable proportions (and preferably with means for drying the same)
substantially as herein described.
3. The hereindescribed process of thawing frozen meat by means of a circulation
of air or gas containing carbonic acid (CO) or other antiseptic gas in suitable
proportions in combination with the use of carbonic monoxide (CO) (and preferably
5 with means for drying the same) substantially as herein described.
በ
4. In the process of thawing frozen meat the employment of carbonic acid (CO,).
or carbonic monoxide (CO) or both (and preferably with means for drying the
same) at a temperature above freezing point to improve the appearance and quality
of the meat when thawed and ready for use substantially as herein described.
Dd this 16th day of July 1895.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.