VINCENT'S CHLORIDE OF METHYL ICE MACHINE.
Chloride of methyl was discovered in 1840 by Messrs. Dumas and Peligot, who obtained it by treating methylic alcohol with a mixture of sea salt and sulphuric acid. It is a gaseous product at ordinary temperature, but when compressed and cooled, easily liquefies and produces a colorless, neutral liquid which enters into ebullition at 237.7° above zero and under a pressure of 0.76 m.
VINCENTS ICE MACHINE. FIG. 1.--THE FREEZER (Longitudinal Section).
Up to recent times, chloride of methyl in a free state had received scarcely any industrial application, by reason of the difficulty of preparing it in a state of purity at a low price. Mr. C. Vincent, however, has made known a process which permits of this product being obtained abundantly and cheaply. It consists in submitting to the action of heat the hydrochlorate of trimethylamine, which is obtained as a by-product in the manufacture of potash of beets. The hydrochlorate is thus decomposed into free trimethylamine, ammonia, and chloride of methyl. A washing with hydrochloric acid takes away all traces of alkali, and the gas, which is gathered under a receiver full of water, may afterward be dried by means of sulphuric acid, and be liquefied by pressure.
VINCENTS ICE MACHINE. FIG. 2.--THE FREEZER (Transverse Section).
Pure liquid chloride of methyl is now an abundant product. There are two uses to which it is applied: first, for producing cold, and second, for manufacturing coal tar colors.
VINCENTS ICE MACHINE. FIG. 3.--HALF PLAN OF FREEZER
At present we shall occupy ourselves with the first of such applications--the production of cold.
The apparatus serving for the production of cold by this material are three in number: (1) the freezer (Figs. 1, 2, and 3), in which is produced the lowering of temperature that converts into ice the water placed in carafes or any other receptacles; (2) the pump (Figs. 4, 5, and 6), which sucks the chloride of methyl in a gaseous state up into the freezer and forces it into the liquefier; and (3) the liquefier, which is nothing else than a spiral condenser in which the chloride of methyl condenses, and from thence returns to the freezer to serve anew for the production of cold.
VINCENTS ICE MACHINE. FIG. 4.--THE PUMP (Longitudinal Section).
The Freezer.--This consists of a rectangular iron tank, 1 meter x 1 meter x 1.5 meters, containing a galvanized plate iron cylinder, A, kept in place by iron supports. This cylinder contains 24 horizontal tubes, which are open at the ends and riveted to vertical plates like those of tubular steam boilers. The tank is filled with a mixture of water and chloride of calcium, forming, as well known, an incongealable liquid. Into this liquid are plunged the receptacles containing the water to be converted into ice. The chloride of methyl is introduced through the cock, B, into the body of the cylinder, A, and surrounds and cools the tubes, as well as the incongealable liquid uninterruptedly circulating in the latter, by means of a helix, C, set in motion by a belt from the shop. This liquid is thus greatly lowered in temperature and freezes the water in the receptacles.
VINCENTS ICE MACHINE. FIG. 5.--VERTICAL SECTION OF THE PUMP.
The Pump.--The pump in the larger apparatus has two chambers of unequal diameter, that is to say, it operates after the manner of compound engines.
The machine under consideration, being one that produces a moderate quantity of ice, has but a single chamber, as shown in Figs 4, 5, and 6. It is a suction and force pump, whose piston, E, is solid and formed of two parts, which are set into each other, and the flanges of which hold a series of bronze segments.
VINCENTS ICE MACHINE. FIG. 6.--PLAN OF THE PUMP.
The chamber, properly so-called, is of iron, cast in one piece, and is surmounted with a rectangular tank, F, in which constantly circulates the cold water designed for cooling the sides of the cylinder; these latter always tending to become heated through the compression of the methyl chloride.
The cylinder heads are hollowed out in the middle, and carry the seats of the suction valves. Each of the latter communicates with a chamber, G G¹, in which debouches the pipe, H, communicating with the cylinder, A, of the freezer (Figs. 1, 2, and 3).
VINCENTS ICE MACHINE. FIG. 7.--THE LIQUEFIER.
Above the cylinder there are two delivery valves which give access to the chamber, D, communicating with the worm of the liquefier (Fig. 7) through the pipe, J.
The piston of the pump is set in motion by a pulley, K, and a cranked shaft actuated by a belt from the shafting. The piston head is guided by a slide keyed to the frame.
VINCENTS ICE MACHINE. FIG. 8.--SECTION OF FLANGE OF THE WORM.
The Liquefier.--This apparatus consists of a cylindrical tank, L, of 3 mm. thick boiler plate, mounted vertically on a masonry base and designed to be constantly fed with cool water. It contains a second cylindrical tank, M, of 6 mm. thick galvanized iron. This latter tank is provided with a cast-iron cover, on which are mounted the worm, N, and a pipe, O, connected with the tube of the pressure gauge. To the base of the tank, M, there is affixed, on a cast iron thimble, a cock, P, for setting up a communication between the tank and the pipe, R, which returns to the freezer through the cock, B (Fig. 1).
VINCENTS ICE MACHINE. FIG. 9.--VIEW OF THE UNDERSIDE OF THE SAME.
The cold water requisite for condensation enters the tank, L, through a pipe terminating in a pump or a reservoir. The waste water flows off through the tubulure, Q. The tank is emptied, when necessary, through the blow-off cock, S.
VINCENTS ICE MACHINE. FIG. 10.--PLAN OF THE WORM.
Operation of the Apparatus.--As has been remarked above, the cylinder, A, is filled with chloride of methyl. The pump, through suction, produces in this cylinder a depression from which there results the evaporation of a portion of the chloride of methyl, and consequently a depression of temperature which is transmitted to the incongealable liquid circulating in the tubes, and to the receptacles (carafes or otherwise) containing the water to be converted into ice.
The pump sucks in the vapor of mythyl chloride through the pipe, H, and through its suction valves, and forces it into the chamber, D, through its delivery valves, and from thence into the worm, N, through the pipe, J. Under the influence of compression and of the water contained in the tank, L, the methyl chloride liquefies and falls into the receptacle, M, from whence it returns to the freezer through the pipe, R.
Two pressure-gauges, one of them fixed on the freezer and the other on the liquefier, permit of regulating the running of the machine. The vacuum in the freezer is 0 to ½ atmosphere, and the pressure in the liquefier is 3 to 4 atmospheres. These apparatus make opaque ice, but will likewise produce transparent, if a pump for injecting air is adjoined. This, however, doubles the time that it takes to effect the freezing, and carries with it the necessity of doubling the number of moulds to have the same quantity of ice.
The cost price of ice made by this system depends evidently on the price of coal in each country, on the perfection of the boiler and motor, as well as on the power of the freezing machine. Putting the coal at 20 francs per ton, and the consumption at 2 kilogrammes per horse and per hour, ice may be obtained at a cost of about half a centime per kilogramme. The apparatus shown in the accompanying figures have been constructed according to the following data:
Production of ice per hour............ 25 kilogrammes.
Production of heat units per hour..... 2.5 grammes.
Quantity of ice produced per
kilogramme of coal burned........... 5 kilogrammes.
Water of condensation per hour........ 0.75 cubic meter.
These machines are employed not only for the manufacture of ice, but also in breweries for cooling the air of the cellars and fermenting rooms, or that of the vats themselves; in manufactories of chemical products; in distilleries; in manufactories of aerated waters, etc.
They may also be used in the carrying of meats and other food products across the ocean, and, in a word, in all industries in which it is necessary to obtain artificial cold.
The power necessary to operate apparatus that produce 25 kilogrammes per hour is about that of 3 horses.--Annales Industrielles.