US1688184A - Handling cane juice - Google Patents

Description

Oct. 16, 1928.

E. E. HARTMANN HANDLING CANE JUICE Filed June 15, 1926 ATTORNEY Patented Oct. 16, 1928.

UNITED STATES PATENT OFFICE- ERNEST EDWARD HARTMANN, OF NEW YORK, N. Y.,- ASSIGNOR TO PETR-EE & DORE ENGINEERS, INC., 01 NEW YORK, N. Y., A CORPORATION OF CUBA.

HANDLING CANE JUICE.

Application filed June 15, 1926. serialno. 116,079.

The general object of my present invention is to provide an improved method of and apparatus for extracting the sugar content from, and disposing of the precipitate commonly called mud, collected in the settling and decantation of sugar cane juice.

The invention is characterized by the provisions made for eifecting an intimate admixtureof the mud with the material forming the bagasse blanket passing through the later stages of the cane milling circuit so as to insure a more thorough retention of the mud in the bagasse than is possible when the mud is fed onto the top of the bagasse blanket as it is in the ordinary practice of the Petree process disclosed in Patent No. 1,266,882, anted May 21, 1918.

I have und that the degree of retention of the mud in the bagasse blanket is in a general way proportional to the aggregate surface area of the bagasse fibre particles to which the insoluble constituents of the mud have an opportunity to adhere. With the bagasse in a finely subdivided condition as it is desirable for the best results in the practice of the Petree process, mud returned to the top surface ofthe bagasse blanket tends to separate immediately into clear liquid absorbed by the bagasse blanket and a slimy layer retained on top of the blanket. Under such conditions the excess of surface of the bagasse particles exposed'to contact with the bagasse fibres is relatively small, and when the blanket with its slimy top layer reaches the next mill in the circuit, a considerably larger portion of the solid portion of the mud is pressed out of the bagasse than is separated from the latter if the mud is mechanically mixed with the material forming the bagasse blanket instead of being merely deposited on top of the latter.

The same general advantage of mechanically mixing the mud and bagasse is obtained with coarsely divided bagasse as with finely divided bagasse. If the baggasse is course the bagasse blanket structure may be quite open, and when the mud is simply deposited on top of the bagasse blanket, the insoluble particles may penetrate quite deeply into the bagasse blanket, but the amount of bagasse fibre brought into contact with the solid particles of the mud is not greatly increased thereby, as such portions of the solid particles of the mud as enter the blanket are then largely held in pockets or cells in the blanket, and to a-considerable extent are pressed out of the latter in the subsequentstages of the milling operation.

In accordance with the present invention, the milling circuit is equipped with provisions for mechanically agitating the bagasse blanket as, or after the mud is returned to the milling circuit and before the mudand the bagasse after being brought together, are subjected to a further juice expressing action.

' These and other features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and orming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described preferred embodiments of my invention.

- In the drawings:

Fig. 1 is a diagrammatic illustration of a three mill crushing plant;

a Fig. 2 is a side view of the mechanical mixing arrangement;

Fig. 3 is an elevation of the rake; and

Fi 4 is a modified arrangement for driving t 1e rake.

The apparatus diagrammatically shown in Fig. 1, includes a three mill crushing plant which consists of a primary mill A,

a secondary 'mill B, and a third mill C;

The rich juice from the mill A is screened at D, collected and limed in the tank E, and

transferred by the pump F through the heater G to the settling vessel H. The clarified juice from the settling vessel H passes to the evaporating plant by the pipe line J, and the mud passes by the pipe line K to the tank L which receives the screened thin juice from the mill 13 via the screen M. The mud and thin juice are limed in the tank L and are then passed by the pump N to the heater 0 and thence to the settling vessel P. The clarified juice from the settling vessel P goes by the pipe line Q, to the tank E, where it mixes with the rich juice and the mixture is defecated. The mud from the settling vessel P is returned to the milling circuit through the pipe line B. at a point between the mills A and B. Maceration water is applied to the bagasse between the mill B and the mill C, and the thin juice from the mill C may be applied either with the mud from the settling vessel P, or separately, to the bagasse. In so far as above described, the apparatus shown is constructed and operated in accordance with the usual practice in plants in which the Petree process is employed.

In accordance with the present invention,

the mud returned to the milling circuit is the bagasse to the mill B. The mud coming back to the milling circuit from the settling tank P through the pipe R'is received by a mud ipe S which discharges into a trough 2 provided with openings S from which the mud drops into contact with the bagasse while the latter is being agitated by the arms T of the agitator T. As shown, the trou h S is supported by arms IV and W" of a rams worl: W. In the construction illustrated the agitator blades T are of equal length and are secured to, and spaced angularly about as well as longitudinally of the mixer shaft T, the angular displacement of longitudinally adjacent blades being 45 in the construction shown. The shaft T is supported by bearings T in the frame W, and driven in the direction of the arrows in Fig. 2, by the sprocket and chain or other driving belt T from the roller A secured on the end of the shaft T. The endless belt conveyor V, driven by the sprocket wheel V and passing over the pulley Wheels V V and V is supported at its edges by the angle irons W secured to the side frames W. The side frames W extend upward and serve to prevent the bagasse from dropping over the sides of the belt conveyor.

In the intended operation of the apparatus as shown in Fig. 2 the mixer arms T engage the bagasse while moving in a direction opposite to the bagasse stream. The arms T are of sufficient length and so ar .ranged that the greater part of the bagasse is collected bythe arms, passed under the trough openings S and discharged by gravity onto the conveyor V at the opposite side of the rotating mixer T from the mill A. This agitation of the bagasse mass while the latter is passing under the openings S insures a much greater surface area of bagasse particles in contact with the mud flowing .down from the openings S than would be had if the mud fell directly onto the top of an unagitated bagasse blanket. Having been mixed with the mud, the bagasse is carthe roller A through the sprocket chain or other driving belt 1 so that the mixer arms engage the bagasse while moving in the same direction as the moving bagasse stream. In the operation of this form of the invention the mud and bagasse are Worked into intimate contact.

The advantages of mixing the mud and I bagasse obviously donot depend primarily on whether the mud returned has or has not been subjected to the special treatment characteristic of the"Petree process before its return.

While in accordance with the provisions of the statutes I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit of my invention as 'set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having now described my invention what I clalm as new and desire to secure by Letters Patent, is Y 1. In the extraction of sugar cane juice by successively crushing and macerating sugar cane, defecating the extracted products, and returning the defecation mud to the milling circuit, the improvement which consists in stirring the bagasse to increase the surface area of bagasse particles brought into contact with'the insoluble portion of the mud.

2. In the extraction of sugar cane juice by successively crushin and macerating sugar cane, defecating t e extracted products and returning the defecation mud to the milling circuit, the improvement which consists in mechanically mixing the mud with the bagasse to increase the retention of the 1 cally mix defecation mud with the bagasse in an intermediate portion of the milling circuit.

4. In apparatus for extracting sugar cane juice from sugar cane, the combination with a milling circuit comprising a series of mills and a travelling conveyor for transporting bagasse from one mill to another in the circuit, of means adapted to mix defecation mud with the bagasse in the milling circuit comprising a mud discharger and a rotating agitator above said conveyor.

5. In apparatus for extracting sugar cane juice from sugar came, the combination of a pair of crushing mills and means for conveying bagasse from one of said mills to the other, of means adapted to add defecation mud to and mix it with the bagasse as the latter is being conveyed from the one millto the other.

6. In a sugar mill, the combination of a pair of mills and means for moving a bagasse blanket from one mill to the other, of means for adding defecation mud to the moving bagasse, an agitator for mixing the mud and bagasse comprising a rotating shaft extending transversely to the direction of blanket movement and carrying arms dipping into the blanket pathway.

7. In a sugar mill, the combination of a pair of crushing mills, of means for mixing defecation mud with the bagasse passing from one of said mills to the other comprising a continuous conveyor transferring agasse between adjacent mills, a defecation mud container having a perforated bottom and located above said conveyor, and a rotating shaft having a series of arms arranged to agitate the bagasse.

Signed at New York city, in the county of New York and State of ERNEST EDWARD HABTMANN.

New York, this 12th day of June, A. D. 1926.

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