Bouscaren's System.—This system, introduced into Guadeloupe by L. F. G. Bouscaren, is shown in Figs. 1351-2. The cane as sliced at e is conducted in measured quantities to eaoh in succession of a circuit of 12 open diffusors r, consecutively subjected to elevation and depression, so as to cause the liquor to flow by gravity from one to the other. Each has a steam-chamber for heating its liquor, that the albuminous impurities in the cane may be coagulated before they mingle with the sugar. Elevation and depression are obtained by supporting the circuit upon an annular double inclined track b, slowly and continuously rotated, each diffusor being held by vertical guides n.
The bottom of each is kept in constant communication with the top of the one next below, by means of an extensible pipe. The apparatus is provided with means of agitating the contents ; a series of straining-diaphragms and devices for keeping their meshes open, so as to retain suspended im purities without interrupting the flow of liquor ; and mechanism for dis charging the spent contents and cleansing the vessel, without inter rupting the operation, and for strain ing and delivering the solid refuse.
At Monrepos, Guadeloupe, with an apparatus consisting of 6 diffusors, juice having a density nearly equal to that of the natural juice is obtained, hour being sufficient for extracting the sugar. The yield of white sugar amounts to 14-13 per cent. of the weight of the cane.
Robert's System.—Julius Robert's process, suffioiently familiar to those engaged in the beet-sugar industry (see pp. 1843-4), is coming into use among cane-planters. The machinery required comprises a 45-H.P. steam engine, cane-cutters, diffusion-vessels, and a heater. The cane-cutters are constructed by Franz Rebicek, of Vienna ; they make about 225 rev.. minute, effect a clean sharp out, ellip tical in shape, 3-4 in. long, and in. thick, and slice up a minimum average of 6000 lb. an hour. The elliptical out severs the maximurn number of central cells, wherein the sugar is said to chiefly reside. The diffusion-vessels are of light boiler iron with cast-irou bottoms. They measure 120 cub. ft., and contain about 4200 lb. of cane-chips and 3250 lb. of water, 10 forming a battery. Each vessel has 5 pipes--for water, to send juice to the heater, to receive juice from the heater, to discharge juice into the clarifiers, and to pass juice from one vessel to another, be sides oue direct from the boiler for steaming purposes, and one for dis charging the water from the vessel be fore emptying the exhausted chips.
The vessels have a manhole at top for receiving the chips, and another 4 ft. sq. next the bottom for discharg ing the exhausted chips. The concen trated juice is drawn from the vessel through perforated false bottom. The heater, of boiler-iron, and in direct communication with the steam-boiler, is used for heating the juice on its passage from ono diffusor to another, as it traverses a system of copper pipes completely surrounded by steam.
Hydrostatic pressure is used in passing juice from one vessel to another, through the heater, and into the sugar-house ; this is obtained by a water-tank of 1500 gaL capacity, placed about 20 ft above the diffusors, As soon as vessel No. 1 is filled with chips, and while No. 2 is being filled, direct steam is let in until it begins to escape at the top. Steam is then shut off, and water is let through the heater until the vessel is full, when the manhole is closed. No. 2 being filled with chips and duly steamed,water is again let down from the tank through the beater into No. 1, driving the liquid into No. 2 through the connecting-pipe. No. 3 is filled, steamed, and charged with juice through No. 2, in the same way. When No. 4 is filled with chips, cold water is let directly from the tank into No. 1, driving the juice which was in it through the heater into No. 2, and from 2 to 3 and 3 to 4. Next, cold water is run into No. 1, and from No. 1 to No. 2, from No. 2 through the heater into No. 3, then directly into 4 and 5, and so on, care being taken to preserve the tempera ture of the last vessels filled at about 88°-93° (190°-200° F.). When the hot juice has passed through No. 7, it is sufficiently concentrated, and is discharged into the sugar-house ; No. 1 is now emptied, and No. 2 becomes the first vessel in the battery, and the work goes on as before, there being always 7 vessels working, one emptying and two refilling : so that practically, when the work is in full operation, as fast as one vessel is filled, a charge of concentrated juice goes into the sugar house, and one vessel with exhausted chips is emptied. The exhausted chips are discharged through the large manhole uear the bottom of the diffusor, and received on a carrier which drops them into the begass carts. A vessel is emptied by two men in 6-8 minutes, including opening and closing the manholes ; filling requires 12-15 minutes.