EVAPORATORS. L711 to within a recent date the most improved process for the evapo ration of juice was that devised by Milieux (see SunAtt-31AKixo MACHINERY, rot.
ii of this work). The principle of Milieux was the evaporation by multiple effect, or the use of the steam of evaporation in the first effect to further concentrate the liquid in the sec ond operation, which is made possible by producing a vacuum in the evaporating chamber of the final effect, thus reducing the boiling temperature of the liquid. The steam in the sur rounding chamber, or jacket. thereby rapidly on the odder surface of the evap orating dumber, and thus not only imparts its latent heat to the liquid, but produces a rela tive vacuum in its own ehandier. The defects of Milieux apparatus are. that a consider able mass of liquid lying above the heating surface, by the pressure of its own weight raises the boiling temperature. of the liquid at the bottom. thus requiring more heat to perform the required work than at the surface, and also subjecting the liquid to a strong heat for an un necessary time. This, in the case of sugar, is a fruitful source of loss, not only by inversion of the sugar, but by forming caramel.
The Yaryan Evaporator is based upon an entirely novel principle. by which the inventor avails himself of the very tendency to blow into spray which viscous liquids possess when subjected to heat, to first blow all the liquid into a spray and keep it subjected to heat in this state. He therefore constructs a horizontal tube of 60 ft. in length and 3 in. in diameter, and surrounded this with another tube, leaving an annular space of sufficient capacity to con tain steam for evaporation. The supply port to the inner tube was reduced to a diameter of in., and the liquid, being fed in under pressure, and steam at ti lbs. pressure supplied to the outer tube, it was found that by the combined action of the liquid entering the tube through the constricted opening, under pressure, and the expansive force of the steam formed by its evaporation, the entire volume of the liquid is ejected from the unobstructed end of the tube in the form of mixed steam and spray. Repeated tests showed a greatly increased efficiency
as the velocity of the liquid in the pipe was increased. The apparatus is adapted to the con centration of fluids, sugar solutions, sugar-cane, beet and sorghum juices, glucose, glue, gelatine, beer-worts, wine, glycerin, extracts of bark, wood, beef, coffee, licorice, alum solutions, caustic soda, waste alkali liquor from paper-mills, tank-waters from slaughter-houses, and for distilling water. Figs. 1, 2 and 3 show a section and perspective views. The process is easily followed from the sectional views (Figs. 1 and 2). The steam for the first effect enters the chamber 0, contain ing the heating tubes If, through the inlet the liquid being fed to the return-bend tubes through the valves D, there being a valve for each coil. Spraying and evaporation at once commence, and the mass is driven through the tubes and is discharged against the baffie plates in the separating chamber 1; thence the steam of the evaporation passes to the next chamber G, while the remaining liquid passes down into the next series of tubes through the valve D. and so on through the system. In the final effect a vacuum is maintained by means of the vacuum-pump and condenser. The legend accompanying the sectional view will serve for the identification of other operative parts. Fig. 3 is a perspective view of the vertical apparatus just described. Fig. 4 is a perspective view of a Yaryan evapora tor of the horizontal type, differing, however, from the other only in the disposition of its parts.
Evaporators: see Engines, Marine.
Excavator: see Dredges and Excavators.
Extractor: see Separators, Steam. Extractor. Centrifugal : see Creamers.
Tan: see Blowers.
Feeder: see Cotton-Gin, Ore-Crushing Machines, and Thrashing-Machines.
Feed-Water Heater: see Engines, Marine, and Heaters, Feed-Water.
Felly-Borer, Telly-Rounder: see Wheel-Making Machines.
Ferro-Chrome: see Alloys.
Filing: see Grinding, Emery.
Filter-Press : see Mills, Silver.