US3272649A

US3272649A - Mingler for temperature conditioning sugar masses

Info

Publication number: US3272649A
Application number: US369705A
Authority: US
Inventors: Richard J Huser
Original assignee: Western States Machine Co
Current assignee: Western States Machine Co
Priority date: 1964-05-25
Filing date: 1964-05-25
Publication date: 1966-09-13
Anticipated expiration: 1983-09-13
Also published as: NL151739B; BE664474A; FR1425825A; DE1567297A1; GB1091152A; NL6506565A; DE1567297C3; DE1567297B2

Description

Sept. 13, 1966 R. J. HUSER 3,272,649

MINGLER FOR TEMPERATURE CONDITIONING SUGAR MASSES Filed May 25, 1964 2 Sheets-Sheet 1 HHHHHIW INVENTOR. RICHARD J.HUSER A TORNEY Se t. 13, 1966 R. J. HUSER 9 2 MINGLER FOR TEMPERATURE CONDITIONING SUGAR MASSES 2 Sheets-Sheet 2 MIHMH iled May 25, 1964 INVENTOR.

R l C H A R D J H U 5 ER A T 0 RN EY United States Patent 3,272,649 MINGLER FOR TEMPERATURE CONDITIONING SUGAR MASSES Richard J. Huser, Mount Healthy, Ohio, assignor to The Western States Machine Company, Hamilton, Qhio, a

corporation of Utah Filed May 25, 1964, Ser. No. 369,705 8 Claims. (Cl. 12717) This invention relates to an improved mingler for temperature conditioning massecuites, magmas and the like.

In the manufacture or refining of sugar, heat is supplied to the massecuite or magma as the material is held in a tank in readiness for delivery into centrifugal machines. Such heating is intended to decrease and hold uniform the viscosity of the material delivered, either continuously or as successive charges, to the centrifugals. This temperature conditioning of the massecuite or magma has been heretofore accomplished by minglers, for example, of the type disclosed in US. Letters Patent No. 2,654,364, to Joseph Hertrich, in which the massecuite, magma or like material is received in an elongated tank having a hollow rotatable shaft extending longitudinally through the lower portion of the tank, and a helical heat transferring-stirrer coil surrounds the shaft within the tank and is connected with the shaft for rotation of the coil with the shaft and for a circulating flow of hot water or other heat transferring fluid through the coil by way of the hollow shaft. The turns of the helical coil are spaced radially from the surface of the hollow shaft so as to permit heat transfer to the material at the entire surface of the coil and also at the surface of the shaft, and further to cause the helical coil to exert a stirring and conveying action on the material in an effort to obtain uniform heating of the material in the mingler tank before such material is passed to one or more centrifugal machines through corresponding outlets at the bottom of the tank.

It has been found that, with the known minglers, as described above, the massecuites or other material may be moved longitudinally through the space between the coil and the shaft as a more or less solid core and thus reach an outlet of the mingler tank for discharge to a centrifugal machine without being subjected to heat transfer and stirring by the coil. Thus, the'efficiency of heat transfer from the hot water or other fluid heating medium to the massecuites or magmas is reduced and uniform temperature control cannot be accurately maintained. The foregoing disadvantages of the existing minglers are particularly apparent when the mingler is associated with modern, high capacity centrifugal machines, such as, continuous centrifugals or batch machines having baskets of forty-eight inch or larger diameter, in which case the size of the mingler tank is increased and the time available for heating the massecuites or magmas is reduced.

Accordingly, it is an object of this invention to provide a mingler affording better heat transfer to the material in the tank and more uniform temperature control.

Another object is to provide a mingler for conditioning massecuites, magmas or like material prior to passing the same to centrifugal machines of high capacity, and wherein the material can be uniformly raised to the desired temperature without employing a coil temperature that is too much higher than the saturation temperature of the massecuites or magmas.

In accordance with an aspect of this invention, a mingler has impeller means, preferably in the form of paddle-like blades, welded or otherwise secured to the hollow shaft and extending into the space between the latter and the turns of the heat transferring-stiffer coil, such impeller means being operative, upon rotation of the shaft, to urge the material within the space between the coil and the shaft in the longitudinal direction opposed to the movement of the material by the coil and also radially outward toward the coil, thereby ensuring that all material in the tank is uniformly subjected to the action of the coil before being passed from the mingler to centrifugal machines.

In accordance with another aspect of this invention, the mingler tank has a compartment therein for each centrifugal machine to which the temperature conditioned material is to be fed, each compartment having an inlet and an outlet for the material spaced apart in the longitudinal direction, and the heat transferring-stirrer coil is arranged to induce longitudinal movement of the material in the direction from the inlet towards the outlet of the associated compartment, while the blades constituting the impeller means on the hollow shaft are arranged to cause longitudinal movement in the opposite direction.

The foregoing, and other objects, features and advantages of this invention, will become apparent from the following detailed description of an illustrative embodiment which is to be read in connection with the accompanying drawings forming a part hereof, and wherein:

FIG. 1 is a side elevational view of a mingler embodying this invention, with the side of the tank thereof being partly broken away to expose the interior construction;

FIG. 2 is an end elevational view of the mingler;

FIG. 3 is a fragmentary top plan view of the mingler;

FIG. 4 is an enlarged sectional view taken along the line 4-4 on FIG. 1;

FIG. 5 is a fragmentary sectional view taken along the line 5-5 on FIG. 4; and

FIG. 6 is a fragmentary sectional view showing the arrangement at one end of the rotary mingler coil unit.

Referring to the drawings in detail and initially to FIG. 1 thereof, it will be seen that a mingler or apparatus for temperature conditioning massecuites, magmas or like material in accordance with this invention is there generally identified by the reference numeral 10 and includes a tank 11 and a rotary mingler coil unit 12 mounted in the tank.

The tank 11 is elongated and preferably of U-shaped cross-section, as shown on FIGS. 2 and 4. The interior of tank 11, particularly in the lower portion thereof, is divided into a number of

compartments

13a, 13b, 13c and 13 d by means of

vertical partitions

14 and 15 extending across the tank. The top of each compartment 13a- 13d is defined by a laterally extending plate or partition 16 which is spaced downwardly from the top of the tank and preferably inclined downwardly toward one side of the tank. The top plates or partitions 16 are preferably hingedly connected, as at 17 (FIGS. 3 and 4) to the side of the tank 11 so that they can be swung upwardly from their normal positions, where they rest on flanges 18 carried by the

partitions

14 and 15 and end walls of the tank (FIGS. 1 and 4), so as to afford access to the compartments 13a-13d.

As shown on FIG. 1, the vertical partitions 14 disposed between

compartments

13a, 13b and 130, in which the same material is to be mingled or temperature conditioned, extend only up to the level of top plates 16 so that the upper portion of tank 11 above compartments 13a, 13b and forms a common supply chamber 19 for such compartments. On the other hand, the partition 15 dividing

compartments

13c and 13d, which are intended to handle different materials, extends above plates 16 up to the top of tank 11 so that the top portion of the tank above compartment 13d defines a supply chamber 20 which is isolated from the previously mentioned supply chamber 19. Each of the top plates 16 has an inlet opening 21 (FIGS. 1 and 3) formed therein adjacent one end of the underlying compartment 13a-13d and also adjacent the relatively low side of plate 16 so that massecuite, magma or other material supplied to the

chambers

19 and 20, as indicated by the flow lines 22 on FIG. 1, can pass from such supply chambers into the underlying compartments through the respective inlet openings.

Although the illustrated mingler has the chamber 19 supplying the same material to three

underlying compartments

13a, 13b and 13c and the chamber supplying a different material to the single underlying compartment 13d, it will be apparent that the location and number of the partitions extending to the top of tank 11 can be changed from that shown to vary the number of compartments serviced by each of the

supply chambers

19 and 20, and further that all of the

partitions

14 and 15 may be made to extend only up to the level of the plates 16, in which case all of the compartments will receive material from the same supply chamber.

Each of compartments 13a-13d further has an outlet opening 23 adjacent the bottom thereof and located near the end of the compartment remote from the inlet opening 21. Loading spouts, which are only generally indicated at 24 on FIGS. 2 and 4 and may be arranged as shown in detail in US. Letters Patent No. 2,086,951, to Stevens, and No. 2,128,873, to Roberts, extend from the lower portion of tank 11 around the outlet openings 23 and are intended to deliver temperature conditioned massecuite or magma from the several compartments of mingler 11 into respective underlying centrifugal machines (not shown).

The rotary mingler coil unit 12 comprises a hollow shaft 25 extending longitudinally through the compartments 13a13d constituting the lower portion of tank 11 and being freely rotatable in suitable openings in partitions 14 and in a seal 26 provided in a suitable opening of partition 15. The hollow shaft 25 is of a strength sufficient to support the weight of rotary unit 12 between bearing assemblies 27 and 28 located at the opposite ends of shaft 25 and carried by the end walls of tank 11. The bearing assembly 27 may be of the kind disclosed in detail in US. Letters Patent No. 3,009,683, to Grieselhuber, whereas reference may be had to US. Letters Patent No. 2,654,364, to Hertrich, for a suitable arrangement of the bearing assembly 28.

The shaft 25 is surrounded throughout substantially its entire length by a concentric heat transferring-stirrer coil which is formed in

sections

29a, 29b, 29c and 29d disposed along the portions of the shaft contained in

com partments

13a, 13b, 13c and 13d, respectively (FIG. 1). One end of the coil section 29a is connected with a chamber 30 (FIG. 6) formed in an end portion of shaft 25 between a partition 31 in the shaft and the end Wall 32 of the latter adjacent bearing assembly 27. Chamber 30 in turn is connected with a hollow extension 33 of shaft 25 which is rotatably supported in bearing assembly 27 and conducts hot Water or other heating fluid away from the mingler by way of a union 34 and an oiftake duct 35, as indicated schematically on FIG. 1 and which are disclosed in greater detail in the previously referred to US. Letters Patent No. 3,009,683. The hot water or other heating fluid is supplied to the mingler 11 through an intake duct 36 which, within the union 34, is connected to a tube 37 extending through shaft extension 33 and chamber 30 and opening into shaft 25 by way of an opening 38 in the shaft partition 31.

The end of coil section 29d near the adjacent end wall of housing 11 is connected with the adjacent end of hollow shaft 25 and communicates with the interior of the latter so that the heating fluid entering hollow shaft 25 through tube 37, at one end, travels along shaft 25 to the opposite end of the latter and there enters coil section 29a. The adjacent ends of

coil sections

29a and 29b, of coil sections 2911 and 290, and of

coil sections

29c and 29d are connected with each other through transfer pipes 39 extending across the interior of hollow shaft 25 in the regions of

partitions

14 and 15, as shown on FIG. 5. Thus, the heating fluid, after having passed axially through hollow shaft 25, then flows successively through the coil sections 29d, 290, 2911 and 2911 before leaving the mingler through chamber 30, shaft extension 33, union 34 and outtake duct 35.

The hollow shaft 25 is of sufiiciently large diameter to serve as a conduit for the heating fluid and also to contribute substantially to the effective heating surface area provided by the assembly of the shaft and coil sections 29a-29d thereon. The coil sections 29a-29d have their turns spaced apart in the axial direction and also radially from the surface of shaft 25, as clearly shown on FIGS. 1, 4 and 5. Such spacing of the turns of the coil sections exposes the entire surface of each coil section for heat transferring contact with the material withinthe related compartment 13a-13d, and further makes it possible to induce longitudinal movement of the material engaged by the coil section upon rotation of the latter with the shaft. As shown particularly on FIGS. 1 and 2, rotation of shaft 25 and coil sections 29a29d may be effected by way of a sprocket 40 secured on shaft extension 33 and engaged by a chain 41 running around a drive sprocket 42 on the shaft of a motor 43.

When the mingler is employed in connection with modern high capacity centrifugal machines, the compartments 13a-13d must have correspondingly large volumes to accommodate sufiicient quantities of massecuite or magma. It is desirable that the spacing between coil sections 29a-29d and the inner wall surfaces of compartments 13a-13d be relatively small, so that material in each compartment cannot move around the outside of the coil section in passing from inlet opening 21 to outlet opening 23. Thus, an increase in the cross-sectional size of each compartment requires a corresponding increase in the pitch diameter of the coil section therein. Since an excessive increase in the diameter of hollow shaft 25 is unadvisable, in that it tends to reduce the capacity of the compartment 13a-13d, an increase in the pitch diameter of the coil sections, as when designing a mingler for use with high capacity centrifugal machines, results in a relatively large radial spacing of the turns of the coil sections from the outer surface of the central hollow shaft.

It has been found that, during operation of a mingler having the construction described above, particularly one designed for use with high capacity centrifugal machines and hence having the coil sections spaced radially a relatively large distance from the surface of the hollow shaft, there is a tendency for the massecuite or magma to move longitudinally through the space between each coil section 29a29d and shaft 25 as a more or less solid core and thereby reach the outlet opening 23 of the related mingler compartment without coming into adequate heat transferring and stirring contact with the coil section. In order to avoid the foregoing, the mingler 10 embodying this invention has impeller means, preferably in the form of paddle-like blades 44 (FIGS. 4 and 5), welded or otherwise secured to hollow shaft 25 and extending radially into the space between the latter and the turns of each of coil sections 29a-29d. The outer ends of blades 44 preferably terminate short of the turns of coil sections 29a-29d, and the blades on the shaft in each compartment 13a-13d slope relative to the axis of shaft 25 in the direction opposed to the slope of the turns of the related coil section. Thus, when shaft 25 is rotated, as described above, blades 44 are operative to induce the material within the space between shaft 25 and each coil section to move longitudinally in the direction opposed to the movement of the material by that coil section and also radially outward toward the turns of the coil section.

As shown particularly on FIGS. 4 and 5, the blades 44 on shaft 25 within each of compartments 13a-13d are spaced apart axially along the shaft and further are angularly spaced apart around the shaft, for example, with 120 angular spacings between successive blades. Further, as shown in FIG. 4, the grouping of the blades in one compartment, as indicated in full lines at 44, is preferably staggered or angularly displaced by 60 from the grouping or arrangement of blades in the next compartment, as indicated in broken lines at 44.

In the illustrated preferred embodiment of this invention, the several coil sections 29a-29d have their helices arranged so that, upon rotation of shaft 25, for example, in the clockwise direction as viewed on FIG. 4, the turns of the coil sections induce longitudinal movement in each of compartments 13a13d in the direction from the related inlet opening 21 toward the outlet opening 23, that is, from left to right, as viewed on FIG. 1. On the other hand, paddle-like blades 44 are arranged so that, upon such rotation of shaft 25, the material in each compartment between shaft 25 and the related coil section is longitudinally moved from right to left, as viewed on FIG. 1, that is, in the direction away from outlet opening 23, and also made to move radially outward toward the turns of the related coil section. By reason of the presence of blades 44, material within the space between shaft 25 and the surrounding coil section cannot reach the outlet opening 23 without first coming into intimate and repeated heat transferring and stirring contact with the turns of coil section 13a-13d.

It has been found that, by reason of the assurance of repeated intimate heat transferring and stirring contact of all the material within each compartment with the related coil section prior to discharge of such material to the associated centrifugal machine, relatively great uniformity and accuracy is achieved in controlling the temperature of the massecuite or magma fed to the centrifugal. Although the drawings do not disclose the means by which the temperature of the discharged material may be controlled, reference may be had to the previously mentioned U.S. Letters Patent No. 2,654,364, for a suitable arrangement for affecting such control.

It has also been found that blades 44 tend to increase the relative velocities of the material in each compartment with respect to the heat transferring surfaces of the coil section therein, thereby correspondingly increasing the efficiency of such heat transfer. Thus, the improved efficiency of heat transfer to the massecuite or magma makes it possible to reduce the temperature of the hot water or other heating medium circulated through shaft 25 and oil sections 29a-29d thereon. Such reduction of the temperature of the heating medium is advantageous in that it makes it possible to employ a temperature that is as little as practicable in excess of the saturation temperature of the massecuite or magma. The fact that a mingler embodying this invention has improved heat transfer characteristics and further effects more uniform heating of the massecuite or magma in each of its compartments makes it possible to relatively reduce the time during which the material must remain in the mingler in order to reach the desired temperature before being loaded into the associated centrifugal machines. Thus, the mingler having the described constructional features is particularly adapted for use in connection with high capacity centrifugal machines.

Although a particular embodiment of the invention has been described in detail herein with reference to the accompanying drawings, it is to be noted that the invention is not limited to that precise embodiment, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention, except as defined in the appended claims.

What is claimed is:

l. In an apparatus for conditioning massecuite or like material, an elongated material receiving tank, a hollow rotatable shaft extending longitudinally in said tank, a

helical heat transferring-stirrer coil surrounding said shaft within the tank and being connected with the shaft for rotation of the coil with the shaft, so that the material in the tank tends to be moved in one longitudinal direction, and for a circulating flow of fluid through the coil by way of the shaft, said helical coil having turns spaced from said shaft so that heat transfer between the circulating fluid and material in said tank occurs at the surface of said shaft and at the entire surface of said coil, and impeller blades extending radially from said shaft into .the space between the latter and said turns of the coil, said blades being spaced apart angularly and axially on said shaft and inclined relative to the axis of said shaft in the direction opposed to the inclination of said turns of the coil to urge the material within said space in the other longitudinal direction and also radially outward toward the coil.

2. An apparatus for conditioning massecuite or like material according to claim 1; wherein said impeller blades have their radially outer ends spaced substantially from said turns of the coil.

3. In an apparatus for conditioning massecuite or like material, an elongated tank defining at least one compartment for containing the material during conditioning thereof and having an inlet and an outlet for the material spaced apart in the longitudinal direction of the tank, a hollow shaft rotatably mounted in said tank and extending longitudinally through said compartment, a helical heat transferring-stirrer coil surrounding said shaft within the compartment and being connected with the shaft for rotation with the latter and for a circulating flow of fluid through the coil by way of the shaft, said helical coil having turns spaced from said shaft so that heat transfer between the circulating fluid and material in said compartment occurs at the surface of said shaft and at the entire surface of said coil, said turns of the coil being adjacent the inner surface of said compartment and sloping in one direction relative to the axis of the shaft to urge material in said compartment in the longitudinal direction from said inlet toward said outlet in response to rotation of said shaft and coil in a predetermined direction, means operative to rotate said shaft in said predetermined direction, and impeller means extending radially from said shaft into the space between the latter and said turns of the coil and terminating short of said turns, said impeller means being operative, upon rotation of the shaft in said predetermined direction, to urge the material within said space in the longitudinal direction from said outlet toward said inlet and also radially outward toward said turns of the coil, thereby to ensure that all material passing through said compartment is uniformly subjected to the action of said heat transferringstirrer coil. 7

4. In an apparatus for conditioning massecuite or like material, an elongated tank defining at least one compartment for containing the material during conditioning thereof and having an inlet and an outlet for the material spaced apart in the longitudinal direction of the tank, a hollow shaft rotatably mounted in said tank and extending longitudinally through said compartment, a helical heat transferring-stirrer coil surrounding said shaft within the compartment and being connected with the shaft for rotation with the latter and for a circulating flow of fluid through the coil by way of the shaft, said helical coil having turns spaced from said shaft so that heat transfer between the circulating fluid and material in said compartment occurs at the surface of said shaft and at the entire surface of said coil, said turns of the coil being adjacent the inner surface of said compartment and sloping in one direction relative to the axis of the shaft to urge material in said compartment in one longitudinal direction between said inlet and outlet, and impeller blades extending radially from said shaft into the space between the latter and said turns of the coil and terminating short of the latter so as to avoid interference with the heat transferring contact of the material with said entire surface of the coil, said blades sloping relative to the axis of the shaft in the direction opposed to the turns of said coil so that, upon rotation of the shaft, said blades urge the material within said space in the opposite longitudinal direction and also radially outward toward said turns of the coil, thereby ensuring that all material passing through said compartment from said inlet to said outlet is uniformly subjected to the action of said heat transferringstirrer coil.

5. An apparatus as in claim 4; wherein said inlet and outlet are respectively located at the top and bottom of said compartment adjacent the opposite ends of the latter; and

further comprising means rotating said shaft in the direction to cause said turns of the coil to urge the material in said compartment in the longitudinal direction from said inlet toward said outlet.

6. In a mingler for controlling the temperature of sugar massecuites, magmas or like material, an elongated tank having lateral partitioning means therein dividing the interior of the tank into upper and lower portions and vertical partitioning means at least in said lower portion to divide the latter into a plurality of compartments, said lateral partitioning means having an inlet opening therein for each of said compartments so that a supply of material maintained in said upper portion of the tank can enter said compartments through the related inlet openings, each inlet opening being disposed adjacent one end of the related compartment and the latter further having an outlet opening adjacent the opposite end thereof, a hollow shaft rotatably mounted in said tank so as to extend longitudinally through said compartments, a helical heat transferring-stirrer coil surrounding said shaft within each of said compartments and being connected with the shaft for rotation with the latter and for a circulating flow of fluid through the coil by way of said shaft, means for rotating said shaft, said helical coil in each compartment having turns spaced from said shaft and sloping in one direction relative to the axis of the shaft to urge material in the related compartment to move longitudinally in the direction from said inlet opening to said outlet opening, and impeller means extending from said shaft into the space between the latter and said turns of the coil in each compartment and being operative, upon rotation of the shaft, to urge the material within said space longitudinally in the direction opposed to the movement thereof by the coil and also radially outward toward the turns of the coil, thereby to ensure that all material passing through each compartment is uniformly subjected to the action of said heat transferringstirrer coil.

7. In a mingler for controlling the temperature of sugar massecuites, magmas or like material, an elongated tank having lateral partitioning means therein dividing the interior of the tank into upper and lower portions and vertical partitioning means at least in said lower portion to divide the latter into a plurality of compartments, said lateral partitioning means having an inlet opening therein for each of said compartments so that a supply of material maintained in said upper portion of the tank can enter said compartments through the related inlet openings, each inlet opening being disposed adjacent one end of the related compartment and the latter further having an outlet opening adjacent the opposite end thereof, a hollow shaft rotatably mounted in said tank so as to extend longitudinally through said compartments, a helical heat transferring-stirrer coil surrounding said shaft Within each of said compartments and being connected with the shaft for rotation with the latter and for a circulating flow of fiuid through the coil by way of said shaft, means for rotating said shaft, said helical coil in each compartment having turns spaced from said shaft and sloping in one direction relative to the axis of the shaft to urge material in the related compartment to move longitudinally in the direction from said inlet opening to said outlet opening, and impeller blades extending radially from said shaft into the space between the latter and said turns of the coil in each compartment, said blades sloping relative to the axis of the shaft in the direction opposed to the turns of the coil and terminating short of the latter so that, upon rotation of the shaft, said blades urge the material within said space in the longitudinal direction opposed to movement of the material by the coil and also radially outward toward the latter, thereby ensuring that all material passing through each compartment is uniformly subjected to the action of said heat transferring-stirrer coil therein.

8. A mingler as in claim 7; wherein said lateral partitioning means inclines downwardly toward one side of said tank and said inlet opening for each compartment is disposed adjacent said one side of the tank.

References Cited by the Examiner UNITED STATES PATENTS 933,934 9/1909 Valerius -92 2,160,533 5/1939 Bonath 127-16 2,540,250 2/1951 Feldstein et al 12758 X 2,654,364 10/1953 Hertrich 127-17 FOREIGN PATENTS 397,432 8/1933 Great Britain.

MORRIS O. WOLK, Primary Examiner.

MICHAEL E. ROGERS, Examiner.

Claims

1. IN AN APPARATUS FOR CONDITIONING MASSECUITE OR LIKE MATERIAL, AN ELONGATED MATERIAL RECEIVING TANK, A HOLLOW ROTATABLE SHAFT EXTENDNG LONGITUDINALLY IN SAID TANK, A HELICAL HEAT TRANSFERRING-STIRRER COIL SURROUNDING SAID SHAFT WITHIN THE TANK AND BEING CONNECTED WITH THE SHAFT FOR ROTATION OF THE COIL WITH THE SHAFT, SO THAT THE MATERIAL IN THE TANK TENDS TO BE MOVED IN ONE LONGITUDINAL DIRECTION, AND FOR A CIRCULATING FLOW OF FLUID THROUGH THE COIL BY WAY OF THE SHAFT, SAID HELICAL COIL HAVING TURNS SPACED FROM SAID SHAFT SO THAT HEAT TRANSFER BETWEEN THE CIRCULAING FLUID AND MATERIAL IN SAID TANK OCCURS AT THE SURFACE