US1709783A - Scum eliminator - Google Patents

Description

April 16, 1929- J. c. ETHEREDGE SCUM ELIMINATOR Filed April 1926 4 Sheets-Sheet WlTN ATTORNEYS April 16, 1929. J. c. ETHEREDGE SCUM ELIMINATOR Filed April 1926 4 Sheets-Sheet 2 lNVEN TOR A J Cz'vwe/rzoee,

WITNESSES ATTORNEYS April 1929. J. c. ETHEREDGE 1,709,783

SCUM ELIMINATOR Filed April 2, 1926 4 Sheets-Sheet 3 U 9 l i zwlwlmimlwl -mll llwlm l INVENTOR Jtzrwcisa ATTORNEYS April 16, 1929. J. c. ETHEREDGE SCUM ELIMINATOR Filed April 1926 4 Sheets-Sheet 4 76 68 CTZTl/f/FfOGQ INVENTOR ATTORNEYS 'l/III IVIIIII. I'IIIIII I will.

Patented Apr. 16, 1929.

UNITED STATES JAMES C. ETHEREDGE, O1 NOBWOOD, LOUISIANA.

SCUM ELIKINATOR.

Application filed April- 2, 1926. Serial No. 99,354.

This invention relates to a scum eliminator especially adapted for use in-the manufacture of cane sugar but it is also well ada ted for use in other industrial processes w ere 5 it is desirable to eliminate suspended matter from liquids under similar conditions.

The object of the invention is primarily to aid in separating from sugar cane juices that portion of the suspended matter or precipitated matter in suspension which is lighter than the juice. Among the former substances is bagacillo and cane wax; substances formed by the action oflime, or lime and sulphurous acid, and heat, (or lime, or

lime and sulphurous acid Without heat) on the juice.

The common. method of removing suspended matter from the juice in the process of sugar manufacture today is by some form of settling, either continuous or intermit tent. The presence in the suspended matter of substances lighter than the juice retards the rate of settling, because the heavier substances haveto drag down those substances lighter than juice against the buoyant action of the liquid. The process is further aggravated by the breaking away from the main bulk of the precipitate of some of the fine particles of light matter, such as the fine particles of bagasse; these particles rise and are drawn off with the clear juice. As it is the common practice to subject the clear juice to no further clarification, these suspended impurities remain in the uice as it is eva orated, and cause fouling of the heating sur ace of the oval orators and vacuum pans, more especially t e former. leading authorities in sugar manufacture this suspended matter also increases the viscosity of the sugar solutions, which re tards the rate of evaporation and thus decreases the capacity of evaporating equi ment. An increase in viscosity also ecreases the capacity of the oentrifugals as well as the quality of the sugar, because massecuite of high viscosity purges slowly, and makes it more diflicult to wash the film of molasses from the surface of the sugar crystals.

Another object resides in the provision of a scum eliminator which effects a more complete removal of the suspended matter from the cane juices and this has the advantage of increasing the evaporating capacity realized in the evaporators and vacuum pans as well as increasing the capacity of the cen- According to' trifugals, of improving the quality of the sugar and also in obtaining a greater yield of sugar and a smaller loss of sucrose in the final molasses by virtue of the fact that the viscosity of the massecuites and of the molasses will be lower and a higher ercenta of the sucrose in the juices can fie crystalllized out.

Other objects and advantages reside in certain novel features of the construction, arrangement and combination of parts which will be hereinafter more fully described and particularly pointed out in the appended claims, reference being had to the accompanying drawings forming a part of this specification, and in which Figure 1 is a view showing the operating parts of the scum eliminator in side elevalOIl,

Figure 2 is a plan view of the scum eliminator with the top of the tank removed,

Figure 3 is a fragmentary plan view of one of the scum collecting floats and its associated deflector,

Figure 4 is a view thereof partly in side elevation and partly in vertical sectlon,

Figure 5 is a sectional view on the line 55 of Figure 3, j

Figure 6 is a fragmentary detail view, partly in elevation and partly in section,

showing the mounting of one of the vanes of the deflector,

Figure 7 is an enlarged view in elevation of one of the vanes and associated parts as seen from the side of Figure 6,

Figures 8 and 9 are sectional views illustrating the supporting and adjusting means employed for the deflectors,

Figures 10 and 11 are sectional views showing the mounting of the radius rods controlling the movements of the floats,

Figures 12 and 13 are detail views of one of the man holes,

Figure 14 is a detail sectional view of one of the unions, and

Figure 15 is a view in section taken on the line 1515 of Figure 14.

Referring to the drawings it will berseen that the scum eliminator embodying the present invention comprises a closed tank,

designated generally at 1, and having a bottom wall 2, a front end wall 3, a rear end .wall 4, side walls 5 and 6 and a top wall 7. The tank is preferably constructed of sheet iron and is braced externally with steel angles 8. Internally the tank 1 is divided into vided with a wash-out three bompartments, designated at 9, 10 and 11, by means of partitions or baflle walls 12 and 13 which extend between and are secured to the sides of the tank and which extend from the top wall of the tank down to within a short distance of the bottom thereof. By reason of the fact that the baflles or purtition walls 13 terminate at their lower ends in spaced relation to the bottom wall of the tank, the lower portions of the compartments 9, 10 and 11 commimicate through these spaces 14 and 15 below the baflies 12 and 13. Except for communication aflorded through the spaces 14 and 15 the compartments 12 and 13 are entirely isolated.

Means is provided for supplying juices to the tank 1 from the heaters and consists of a supply pipe 16 connected to the front end wall 3 of the tank and discharging into the lower portion of the compartment 9 of the tank beneath the curved baffle 17 having a flange 18 fastened to the front wall 3 and having a perforated body portion 19 which extends from a point over the supply pipe 16 down to withina short distance of tie bottom 2 of the tank. The baflle 17 extends for a substantial distance on each side of the supply pipe and serves to distribute the incoming juices acrossthe compartment 9 and to arrest their velocity to some extent. At the opposite end of the tank from the supply pipe 16 an outlet, designated generally at 20, is provided, the outlet having a U-shaped portion 21 includin a leg 22 coupled to the bottom of the ta adjacent the end wall 4 and communicatin with the compartment 11. The outlet 20 a so includes a stand pipe 23 leading up to a lateral 0&- take 24. The U-shaped ortion 21 is protting 25 and the lateral ofitake 24 is provided with a vent 26 to prevent siphoning. The U-shaped portion 21 provides a seal or trap which, together with the column of juices or liquid in the stand pipe 23 prevents undesirable blowofl of the juices as will hereinafter more clearly appear.

Automatically operable scum collecting means are provided in the several compartments, the automatic scum collecting means of the compartment 9 being designated generally at 30, that of the compartment 10 being designated generally at 31 and that of the compartment 11 being designated generally at 32. These automatically operable scnmcollecting means are all of identical construction and a common description will serve for all.

Eaehiofthe scum-colleeting'means 30, 31 and-32 includes a south collector in the form of a box-like float 35 illustrated in detail in Figures 3, 4 and 5. Each float 35 has a false bottom therein made up of sloping walls 36 which lead down to'the discharge opening 37 of the collector. An elbow 38 the top and the upper edges of the side is coupled to the bottom of the collector and communicates with the discharge opening 37 and the lateral arm of this elbow connects with a union 39 coupled by means of an elbow 40 to one end of a pipe 41, the opposite end of which pipe 41 is connected to an elbow 42 which has connection with a union 43, the union 43 being connected to a lateral pipe 44 which leads through the side of a tank and which connects with the scum line 45. By means of this arrangement the scum is carried off from the collector in all of its positions. The unions 40 and 43 may be of any desirable eonstruc tion but one preferred form of union is illustrated in F igurcs 14 and 15 and consists of an outer casing 41 having a nipple 41 ,threadedly connected thereto and confining therein a swivel nipple 41, the nipple 41 having an annular flange 41 co-act-ing with an annular flange 41 on the casing 41. Be tween the swivel nipple 41 and the fixed nipple 41 a packing space 41 is provided. Each collector 35 has an open top although a cover, designated generally at 50, overlies the open top, the cover 50 being supported above the top by being secured to an extension 35 of one of the walls of the collector and by virtue of its mounting on the opposite wall of the collector by means of a pair of spaced angle brackets 51 and an intermediate supporting bracket 52. The extension 35 of one of the walls of the collector serves to close the rear side of the collec-- tor but inlet spaces or openings 53 and 54 are provided in the opposite side of the collector and at the ends thereof, said spaces being defined by the overlying portions of wall and end walls.

A baifle 55 is provided for the inlet space 53 and decreases in size from its center to its ends as shown in Figure 5. Baflles 56 are provided for the inlet spaces 54 and consist simply of angle irons of uniform size throughout their length. These batlles are spaced inwardly of the inlet openings, as illustrated in Figs. 4 and 5.

The cover 50 is provided with an upwardly inclined extension 57 around the marginal edges of which upstanding angle irons 58 are secured. Water is delivered onto. the extensions 57 of the covers by means of transversely extending water supply pipes-58 provided in the upper portion of each compartment and receiving water from a main water supply pipe 58", the water supply pipes beingperforated in their under portions so as to spray water onto the extensions 57 of the covers. The water so sprayed runs down the extensions 57 of the covers and passes through series of openings, designated at 59 and 60, the series of openings 59 extending transversely of the cover above though just inwardly of the inlet space 53, the series of openings 60 extending above though inwardly of the inlet spaces 54. Upstandin angle irons 61 and 62 insure the flow of tie water through the openings 59 and 60, and in this way the edges of the box-like float making up the collector and co-acting with the cover to define the inlet spaces are kept clear of rcum and deposits of the same are prevented from building up thereon. The wvater flowing through the openings 59 and 60 is directed onto these edges by the action of the baflles 55 and 56. v It may be desirable to weight the floats and for this purpose an upstanding pin (35 is provided on the cover of each float or collector and is adapted to receive any desirable number of weights 66, as shown in Fig. 1.

Each float or collector is constrained in its movementsxjand maintained upright in all positions by means of a pair of radius rods 67 ivotallyconnected, as atGS in Fig. 10 to t 1e float and also pivotally mounted on a transverse shaft 69 mounted in one of the side walls of the casing and in a lug 69 provided on the opposite side wall. As illustrated in Figs. 10 and 11 the radius rods have free pivotal connections with their floats and with their shafts-but are prevented from transverse displacement by pins or keys 67 The radius rods are of the same length as the pipe 41 connected with their float and describe parallel arcs with respect to said pipe so that all of thc 'e parts move up and down at the same rate and thereby maintain the floats upright in all phases of the operation.

A deflector, designated generally at 70 is provided in connection with each collector for the purpose of deflecting the scum, steam and air into the box-like float making up the collector. Each deflector includes a plurality of plate-like vane 71 which are illustrated in Figs. 6 and 7 as having sleevelike bearings 72 and 73 at their ends to receive pivot rods 74 and 75. The pivot rods 74 are pivotally connected to longitudinally extending supporting bars 76 which extend along the sides of the vane and which are suspended from the extension 57 of the cover by means of hanger bars 77 connected to the bars 74 and adjustably connected by suitable bolts and nuts to brackets 78 fastened to the extension 57. The vanes have centrally located and longitudinally aligned slots 79 in their lower portions to permit a lower adjusting rod 80 to pivotally receive the rods 75. The bar 80 is adjustably connected, as at 81, to a vertically adjustable fastening member 82 which has sections 82 and 82 adjustably connected to each other and releasably fastened to portions of the bracket 52 secured on the collector. The inclination of the vane 71 may be varied by adjusting the bar 80 and the mounting memher or fastening member 82.

When the liquid or juice falls below a certain level in the tank the floats are supported on supporting brackets or rests 85 suitably mounted and secured to the partitions. 12 and 13 and to the end wall 4.

Man holes 86 are provided to facilitate access to the interior of each compartment and are normally closed by covers 86 held to the tank by nuts 8G threaded on studs 86 welded to the tank. A marginal reinforce 86 may be welded to the tank around each manhole.

Each compartment also has a window 87 to permit of an observation of the process going on therein and in order that the window may be maintained clear valve controlled spray pipes 88 are provided for the windows and receive a supply of clear water from a water supply pipe 89.

Means is provided for producing uprising jets of air through the compartments 9, 10 and 11 when this is desirable and in the illustration shown such means consists of a plurality of air jet supply pipes 90 supported by brackets 91 on the bottom wall 2 below each compartment, the pipes 90 receiving a supply of air from a manifold 92 which in turn receives compressed air from valve-controlled branch pipes 93 leading from a main compressed air supply pipe 94.

The operation of the eliminator is as follows: Juice from the juice heaters enters the closed tank, striking the perforated batfle plate. The purpose of the bafile is to decrease the velocity of the juice and to deflect portions of it to, the right and to the left of the inlet, thus resulting in a more uniform flow of the juice across the first compartment. The incoming juice flows across the first compartment into the second and third compartments until the juice level rises to the lower edges of the baffles between the compartments. The temperature of the incoming juice is, we will assume, 215 degrees Fahrenheit. The pressure inside of the eliminator upon starting is atmospheric. Now, when average cane juice at 215 degrees F. is released at atmospheric pressure, a flash of steam occurs; the steam continues to be given ofi until the juice cools to the boiling point. At the same time, air, which has been entrapped in the juice before it is pumped to the heaters, having risen in temperature along with the juice, rises from the juice more rapidly than it would rise from cold juice; because, having been unable to escape in the heaters, the volume of air in the hot juice is practically the same as it was before being heated. Thus its pressure has increased to above that of the atmosphere, and it will rise and escape from the surface of the juice- This mixture of escaping steam and air will build up a-pressure in lit) compartment, saturation of this va or space will proceed more rapidly than be ore, and the pressure will soon become greater than the pressure in the vapor space of com artment 10. As this occurs the level 0 the juice in the first compartment will become lower than in the second compartment, because the greater pressure in the compartment 9.will force juice into com artment 10 1nore rapidly. In like manner t e juice entering compartment 10 will give ofl' more steam and air, raising the vapor pressure to a greater value than obtains in compartment 11. Thus, when the pressure in compartment 10 increases to much above that in compartment 11 the level of the uice in 10 will be forced down lower than in No.

11. Or, vice versa, the juice level will highest in the third compartment, lower m the second, and lowest in the first compartment.

The rising juice in each compartment will carry up the floats. By constructlon the radius arm, being a radius of the same length as that constituted by the movable piping serving union immediately below outlet of float, the pin attached to its movable end describes an are identical to that described by this union, and all portions of the float and float cover rise at the same rate; thus the floats remain in upright positions.

In the meantime a portion of the air and steam in the first compartment escapes through the opening into the float, thence through the movable pipe and unions and scum line to the scum, or mud tank. But in rising to the surface of the juice in compartment No. 9 the air and steam carries with it a considerable amount of suspended matter. Most of that matter which is lighter than the juice will remain on the surface, forming a scum. The current of steam and air, passing under the extended portion of the top of, the float, will produce a current in the scum toward the entrance to the float. The production of this current is aided by the Work of the scum deflectors which deflect the scum and rising steam and air towards the floats. When the blanket of scum builds up to a suflicient depth to reach the inlet to the float the pressure of the steam and air will force the to portion of it into the float; and thence it Wlll be carried through the movable pipe to the scum line and thence to the scum tank.

The same operation occurs in the second and third compartments.

The juice, having given up a portion of its heat in com artment No. 9 will enter compartment 0. 10 at a lower temperature; but the scum outlet pipe of compartment No. 9 is designed so that it has not suflicient capacity to carry away the scums and the flash obtained from a temperature drop of from 215 degrees F. down to-the atmospheric boiling temperature of the juice. Therefore the tem rature of the juice cannot drop to atmos eric boiling temperature in com artment o. 9.

But a temperature still 0 taining in the 'uice entering compartment No. 10 which is igher than it could be in the open atmoshere, a flash must occur in compartment 0. 10, and continue, to reach and maintain a saturated condition in the vapor space of compartment No. 10. This flash of steam and air escapes through the float and connecting piping as described above for compartment No. 9, carrying with it scums which have risen to the surface.

The same operation occurs in the third compartment.

- The scum lines are inclined toward the scum tank (this tank not shown in drawing) in order to facilitate their flow. The

should each have a valve near the scum ta to permit closing the scum line from any compartment should for any reason a float be swamped and sink, although this is not an essential part of the invention.

The 'uice outlet of the eliminator is curved.

upwar to give a seal in the last compartment of a minimum of 5 ft. so that if there is about 2 lbs. pressure per square inch difference in the vapor s aces of the first and last compartments, still the juice level in compartment No. 9 will be above the lower edge of the first baflle and steam will not blow under the baflie into the second compartment. If this difference of pressure increases to much more than 2 lbs. per square inch then steam will blow from the first compartment under the baflie into the second and will disturb the even working of the apparatus. For working under higher pressure the eliminator should have a greater height and the height of the seal at the last compartment should be increased by extendin the juice outlet further up.

when it is desired to force more air through the juice, in addition to the amount it normally contains, and thus carry a greater amount of the suspended matter to the surface, compressed air is turned into the perforated coils in the bottom of the eliminator. .This air will rise through the juice, carrying with it additional suspended matter and at the same time will cause an increase in pressure in the vapor spaces of the compartments, thus increasing the scum-carrying capacity of the scum lines.

While designed primarily for use in the manufacture of cane sugar, this eliminator may also be used in other industrial processes should its use be of benefit in said processes. Again it may be used for the removal of suspended matter from cold liquids by the use of compressed air in the air coils. In operating with cold liquids, the pressures in the vapor spaces of the various compartments is formed by the air rising from the surface of the juice, instead of a mixture of air and steam. Otherwise the operation is the same as with hot liquids.

It is obvious that the present invention involves a method which consists in forcing the heated juices under pressure greater than atmospheric into one end of a closed tank having a series of compartments communicating at their lower ends only and in which the pressure of the atmosphere exists, withdrawing the juices from the other end of the tank through a liquid seal and causin the steam and air rising from the surface '0 the juices in the several compartments to carry off the scum and suspended matter.

I claim 1. A scum eliminator com rising a'closed tank having a plurality of compartments therein, said compartments having t ir lower portions communicating, ascum co lect-ing float in each compartment having an inlet opening for the scum, means for carrying ofl the scum from the floats, and a deflector associated with each float.

2. A scum eliminator comprising a closed tank having a plurality of compartments therein, said compartments being arranged in tandem and having their lower portions communicating, means whereby heated liquid to be treated may be introduced into an end compartment, a scum collecting and discharge means for each compartment adapted to.collectand discharge a limited amount of scum in a manner to control the heat of the liquid as the same passes to each compartment.

3. A scum eliminator comprising a closed tank having a plurality of compartments therein, said compartments having their lower portions communicating, a scum collecting float in each compartment having an inlet opening for the scum, means for carrying off the scum from the floats, means for constraining the floats to proper movements and consisting of radius rods pivotally mounted on the tank and pivotally connected to the floats, and means for positively supporting the floats in their lowermost positions.

4. A scum eliminator comprising a tank, a scum collector in said tank and comprising a box-like float having an open top, a cover overlying the top and supported thereon and co-acting with the float to define the inlet openings, and means for carrying ofl the scum from the scum collector in allpositions thereof.

5. A scum eliminator comprising a tank,

a scum collector in said tank and comprising a box-like float having an open top, a cover overlying the top and supported thereon and co-acting with the float to define the inlet openings, and means forL zcarrying 011' the scum from the scum collector in all positions thereof and comprising a pipe havin swivel connection with the float and ,with t e tank.

6. A scum eliminator com rising a tank, a scum collector in said tan]? and comprising a box-like float having an open top, a cover overlying the to and supported thereon and co-acting wit the float to define the inlet openings, means for carrying of the scum from the scum collector in all positions thereof, said cover having an upwardly inclined extension, and a deflector co-acting with the extension for deflecting the scum into the float.

7. A scum eliminator comprising a tank, a scum collector in said tank and comprising a box-like float having an open :2 a cover overlying the top and suppor d thereon and co-acting with the float to define the inlet openings, means for carrying off the scum from the scum collector in all positions thereof, said cover having an upwardly inclined extension, a deflector co-acting with the extension for deflectin the scum into the float and consisting o a plurality of vanes, and means for angularly adjustin the vanes and supporting them in adjuste position.

8. scum eliminator comprising a tank, a scum collector in said tank and comprising a box-like float having an open top, a cover overlying the top and supported thereon and co-acting with the float to define the inlet openings, means for carrying ofi the scum from the scum collector in all positions thereof, clined extension, 9, deflector co-acting with the extension for deflectin the scum into the float and consisting 0% a lurality of vanes, means for angularly adiusting the vanes and supporting them in adjusted position and comprising longitudinall extending barspivotally connected to t e vanes, hanger bars adjustably supporting certain of said longitudinal bars on the extension of the cover, and means co-acting with the other longitudinal bar for holding it in an one of a plurality of adjustments where y to maintain the vanes in proper adjustment.

9. A scum eliminator comprising a tank, a scum collector in said tank and comprising a box-like float having an open top, a cover overlying the top and supported thereon and co-acting with the float to define the inlet openings, and means for carrying off the scum from the scum collector in all positions thereof, said cover having perforations overlying the portions of the float which co-act with the cover to define the inlet openings, and means for supplying water to said persaid cover having an upwardly inj forations whereby to wash the said edges clear of deposits and accumulations of scum.

10. A scum eliminator comprising a closed tank includin a bottom wall, side walls, and a to wall, ba es within the tank and extendtween the side walls and connected to the to wall, said bafiies terminating short of the ttom wall whereby said baflies define compartments within the tank which communicate with each other at their lower portions only, means for supplying heated liquid to one of the compartments, a scum collecting float in riach compartment having an inlet 0 ning or the scum, means for carrying 0 the scum and the heated air and steam rising up above the level of the liquid of each compartment and flowing into the scum collectin float therein, and means for carrying ofl t e li uid from the compartment remote from t e inlet and comprising an outlet havin a trap and a column.

11. A scum e iminator comprising a closed tank including a bottom wall, side walls, and a to wall, baflies within the tank and exten between the side walls and connected to the top wall, said baflies terminating short of the bottom wall whereby said baflies define compartments within the tank which communicate with each other at their lower Portions only, means for supplying heated 1 uid to one of the compartments, a scum co ecting float in each compartment having an inlet 0 ening for the scum, means for carrying o the scum and the heated air and steam rising up above the level of the liquid of each com artment and flowing into the scum collectlng float therein, means for carrying off the liquid from the compartment remote from the inlet and comprisin an outlet having a trap and a column, an also having a vent to prevent siphoning.

12. A scum eliminator comprising a closed tank having a plurality of compartments therein, said compartments having their lower portions communicating, a scum collecting float in each compartment having an inlet opening for the scum, means for carrying off the scum from the floats, and means for constraining the floats to proper movements and consisting of radius rods pivotally mounted on the tank and pivotally connected to the floats.

JAMES C. ETHEREDGE.

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