US722636A - Evaporating-pan. - Google Patents

Description

PATENTED MAR. 10, 1903. E. R. SHAW. EVAPORATING PAN.

APPLICATION FILED rm. 2. 1901.

N0 MODEL.

3 SHEETS-SHEET 1.

No. 722,636. PATENTED MAR. 10, 1903. E. R. SHAW. EVAPORATING PAN.

APPLICATION FILED FEB. Z. 1901.

NO MODEL. 2 SHEETS-SHEET 2.

UNITED STATES HATENT rFIcE.

ELTON R. SHAW, OF ONTARIO, CALIFORNIA.

EVAPORATlNG-PAN.'

SPECIFICATION forming part of Letters Patent No. 722,636, dated March 10, 1903.

Application filed February 2, 1901. Serial No. 45,669. (No model.)

To all whom it may concern:

Be it known that I, ELTON R. SHAW, a citizen of the United States, residing at Ontario, in the county of San Bernardino and State of California, have invented an Evaporating- Pan, of which the following is a specification.

My invention relates to improvements in evaporating-machines in which the film system of evaporation is employed; and the. object of my invention is to provide a continuous concave curved surface upon which the film of evaporating material is to be disposed and upon which a current of the air-absorbent medium may be made to continuously impinge directly upon the film so as to break up and remove the protecting air film that covers the liquid film in order to effect a more thorough, intimate, frictional, and continuous contact and repetition of such contacts with the surface of the liquid film that has been formed or is being continuously formed and reformed upon the curved surface mentioned and whereby the liquid under treatment is carried progressively thereon while being continuously exposed in the form of a thin film from the inlet or charging point of the apparatus to the outlet or discharging point in a regular and positive manner, so as to give full and complete control over the liquid under treatment during the entire operation. The liquid under treatment moves continuously in one direction under the influence of gravity alone, and the air moves in an opposite direction continuously under force of pressure, preferably mechanical. I attain these objects by the mechanism illustrated in the accompanying drawings, in which- Figure l is a side elevation of the evaporator,part sectional; Fig. 2, an end elevation of the same, part sectional; Fig. 3, a plan view of the same,part sectional; and Fig. 4, an ele vation of the evaporator within a housing.

Similar letters refer to similar parts throughout the several views.

A is a horizontal unilocular pan, spirally projected, composed of sheet metal or other suitable material, preferably provided with flanges A A at both sides of the pan for the purpose of preventing the overflow of liquid charges therefrom. The outer end of this pan'A is formed into a trough-like receptacle running the entire width of the pan and designed to be charged with and emptied of a certain amount of the liquid to be evaporated at each revolution of the apparatus when the pan reaches the proper point for that purpose and automatically.

B B are hollow hubs provided with spokes B B. The pair of hubs and the spokes of each are rigidly connected and held together and equally spaced from each other by means of the tie-bolts B and the spacing-thimbles B or other suitable means, the spiral pan being placed between them and secured to and held in position by means of the said hubs and spokes. The pan-body is suspended in a horizontal position by or carried upon the supporting-frames O C. The hollow hubs B B rest in cradles formed by the car-wheels O and the axle O on each side of the apparatus. Provision is made for the discharge of the liquid from the inner end of the spiral pan when it reaches that point by way of the contracted and tapered tubular inner end of the spiral pan at D, the projection of the pan at that point extending through and out of the hollow hub B at the outlet D, the flanges at this point being omitted to permit free delivery of the liquid from and over the edge or at the side of the pan. The shutters E E are located between and may slide in the grooves in the spokes and make contact with the flanges at either side of the pan, so as to form an inclosure; but these shutters are removable for the purposeof permitting the cleaning of the pan and form when in place the sides of a continuous air-duct from the center to the outer end of the spiral pan.

F F is a catchment trough and pipe to receive the evaporated material and conduct it away from the apparatus to a suitable storage-receptacle.

G is the feed-pipe of the apparatus which connects the feed-tank G with the chargingtrough end of the pan A This feed-pipe is provided with a universal joint G in order to permit the unilocular pan to revolve.

H H are air-inlet ducts located on each side of the machine. They telescope loosely inside of the hubs B B, but have no direct rigid connection therewith. The air-exit is located at the outer end of the evaporatingchamber between the feed-trough A and the adjoining inner spiral portion or body.

The operation of the evaporator may be described as follows: Power being applied to one or both of the axles O in the proper manner, the unilocular pan A is caused to revolve in the direction indicated by the arrow at the top of Fig. 2 through frictional contact between the car-wheels O and the hubs B B, the speed of rotation being regulated to correspond with the amount of evaporation to be accomplished. The supplytank G which is preferably of size double the maximum single charge of the apparatus, is placed on a level with the axis and center of the apparatus, so that with the feed-valve Gr open the liquid will not begin to run into the trough A until in its downward revolution it has reached a point on the horizontal diameter of the apparatus. The liquid then begins to flow into the trough A through a perforated pipe located therein and is held therein until the trough has reached the lowest point of its revolution, after passing which it begins to discharge its liquid contents by gravity action, and the liquid continues to feed and at the same time flow down on the inner surface of the outer spiral of the pan from the perforated pipe in the feed-trough until the latter has reached the point shown in Fig. 2, when the liquid will cease to flow through the feed-pipe, the feed-trough having reached the level of the supply-tank. The charge thus delivered to the machine always seeks and tends to remain under control of gravity in the lowest point or part of spiral of the pan, the concave surface of the pan taking therefrom by adhesion a continuing film of liquid as the apparatus revolves. The successive charges, however, remaining by gravity at and near the lowest points of the spiral progressively and continuously, but in diminishing volume, flow from the outer to the inner end of the spiral, gaining one spiral at each revolution, so that theoretically the apparatus as illustrated in the drawings will require seven revolutions in order to send the charge from the outer or charging end of'the spiral toits inner ordischarging end. At each successive revolution of the apparatus a new charge is delivered into the outer end of the spiral pan, and this charge passing over the same surface washes off the film left by the previous charge, leaving another film in its stead, this operation continuing and being repeated indefinitely as the apparatus is revolved. Simultaueouslywith the introduction of the first liquid charge and continuously thereafter air is forced into the evaporatingpan and chamber through the air-ducts H H at sufficient pressure toinsure ahigh velocity and am temperature suitable to the work to be performed. The two currents of air entering from the opposite sides of the apparatus and meetingin the center thereof are defiected,and changing their direction together follow the unilocular chamber formed by and between the spiral pan-surfaces and the shutters E E, the air-current being continually diverted from its natural straight course by the concave surface of the pan, and thereby being brought into intimate frictional contact with the liquid film spread thereon, from which, owing to its absorptive nature, the air takes up and carries away in its course the water content of the liquid so absorbed and eventually passes out of the machine with its load of moisture. Necessarily, therefore, as the liquid charges progress from the outer to the inner spiral their bulk is greatly lessened and their density increased. This progressive increase in density, however, takes place coincidently with the progressively-decreasing pe ripheral speed of the continuous inner surface of the concave spirals,which diminished speed gives time for the action of gravity to overcome the increasing viscidity of the liquid under treatment and to spread the liquid over the entire concave spiral surface of the pan. The rapid current of air impinging sharply against the concave surface of the pan or of the liquid film spread thereon serves to break up the air film or layer on the surface of the liquid film and also to prevent any particles of the liquid from leaving the film and filmsurface in the form of drops or otherwise, the tendency everywhere being to force the liquid back against and keep it spread upon the surface of the pan by the air pressure and current.

While I preferably force the air through the apparatus from the inner to the outer point, discharging it into a chamber surrounding the apparatus, it is also possible in my invention and in some cases may be desirable to induce a current of air through the apparatus by exhausting the air from the outer end of the pan and from the surrounding chamber instead of forcing the air into the spiral chamber from the center of the apparatus. Then this is done, it gives a current of induced air in the apparatus which has an entirely different method of action, contact, and effect. When the air is forced in and through the spiral chamber, it takes effect more directly upon the concave spiral surface of the chamber; but when it is induced it takes effect more directly upon the convex side and surface of the pan, gliding along that surface, and in that case if the air be heated to a relatively high temperature it will act as an evaporating medium, acting through the bottom of the pan and on the under side of the filmnamely, that adhering to the concave side of the pan-surface. For some liquids this may be not only a suitable but a more desirable method of treatment. 1 do not, therefore, confine myself to forcing air through the apparatus, but may use the induced cnrrentinstead. In this way by the mere change from the use of a forced to the use of an induced current of air I am able to evaporate either by absorption from the surface of the liquid film or by evapora tion through heat communicated to the film through the metal surface upon which it is spread.

The method of controlling this apparatus during its operation is very simple. It consists in regulating the amount of each successive liquid charge in proportion to the speed of rotation and capacity of the evaporating medium and in proportion to the original density of the liquid being treated and the desired density after evaporation. In all cases the rotation of the pan need be only rapid enough to insure the liquidity of the film to a suflicient extent to admit of its being acted upon or mingled with subsequent charges and making proper exit.

My invention in addition to its use as an evaporator may also be used for the rapid cooling of liquids by means of cold-air currents forced or induced through the apparatus for charging liquids with various gases, and also for otherwise changing the chemical nature of liquids through an air-current acting as a vehicle for chemical elements or compounds. The number of spirals may be changed to any desired number.

I claim as my invention- 7 1. An evaporator forliquid compounds consisting of a rotating body composed of a unilocular pan, spirally projected or formed, with closed sides, forming a continuous spiral air-duct for the passage of the evaporating medium, supported in a horizontal and easily-revoluble position, substantially as described.

2. An evaporator for liquid compounds consisting of a rotating body, composed of a unilocular pan, spirally projected or formed, suspended and held by and between hollow hubs with radiating spokes attached thereto and removable shutters fitted between the spokes, supported in a horizontal and easily-revoluble position upon cradles formed of flanged wheels, axles, and journals, substantially as described.

3. An evaporatorforliquidcompoundsconsisting of a horizontal, rotating, unilocular pan, spirally projected or formed, suspended and held by and between hollow hubs with radiating spokes attached thereto, removable shutters fitted between the spokes, forming a continuous spiral air-duct for the passage'of the evaporating medium, the whole rigidly connected together to form a single member supported in an easily-revoluble manner upon cradles formed of flanged wheels, axles and j ournals,substantia1ly as described.

4. An evaporator for liquid compounds consistin g of a horizontal rotating unilocular pan, spirally projected or formed, suspended and held by and between hollow hubs with radiating spokes attached thereto, removable shutters fitted between the spokes forming a continuous spiral air-duct for the passage of the evaporating medium, the whole rigidly connected together to form a single member, supported in an easily-revoluble manner upon cradles formed of flanged wheels, axles and journals, substantially as described, in combination with means for conducting the liquid compound to be evaporated from the source of supply to a feed-trough at the outer end of the pan, whereby the liquid is permitted to flow onto and over the concave surface of the spiral pan continuously by charges.

5. An evaporator for liquid compounds consisting of a horizontal, unilocular pan, spirally projected or formed, suspended and held by and between hollow hubs with radiating spokes attached thereto, removable shutters fitted between the spokes forming a continuous spiral air-duct for the passage of the evaporating medium, the whole rigidly connected together to form a single member, supported in an easily-revoluble manner upon cradles formed of flanged wheels, axles and journals, substantially as described, in combina tion with the means for rotating the spiral pan, whereby the liquid being continuously charged into the pan is caused to develop a film of the liquid over and upon the inner, concave surfaceof the pan, progressively and in the same direction from the outer or charging end of the pan to the inner or discharging end, substantially as described.

6. An evaporator forliquid compounds consisting of a horizontal, unilocular pan, spirally projected or formed, suspended and held by and between hollow hubs with radiating spokes attached thereto, removable shutters fitted between the spokes forming a continuous spiral air-duet for the passage of the evaporating medium, the whole rigidly connected together to form a single member, supported in an easily-revoluble manner upon cradles formed of flanged wheels, axles and journals, substantially as described, in combination with the means for rotating the spiral pan, whereby the liquid being continuously charged into the pan is caused to'develop a film of the liquid over and upon the inner, concave surface of the pan, progressively and in the same direction from the outer or charging end of the pan to the inner or discharging end, substantially as described, and with means for conducting the atmospheric air or other evaporating medium at high velocity to and into the center of the apparatus and through the spiral air-duct over and upon the exposed surface of the liquid film, substantially as described.

7. An evaporator for liquid compounds consisting ofa horizontal, unilocular pan, spi rally projected or formed, suspended and held by and between hollow hubs with radiating spokes attached thereto, removable shutters fitted between the spokes forming a continuous spiral air-duct for the passage of the evaporating medium, the whole rigidly connected.

together to form a single member, supported in an easily-revoluble manner upon cradles formed of flanged wheels,-axles and journals, substantially as described, in combination with the means for rotating the spiral pan, whereby the liquid being continuously I through the spiral air-duct over and upon the charged into the pan is caused to develop a exposed surface of the liquid film, substanfilm 0f the liquid over and upon the inner, tially as described, and also in combination concave surface of the pan, progressively and with the means for carrying away the par- 5 in the same direction from the outer or chargtially-condensed liquid.

ing end of the pan to the inner or discharging end, substantially as described, and with ELTON SHAW means for conducting the atmospheric air or 'Witnesses: other evaporating medium at high velocity to EDWARD S. BERRALL,

10 and into the center of the apparatus and JAMES A. SKILTON.

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