US3800865A

US3800865A - Heat exchanges

Info

Publication number: US3800865A
Application number: US00142314A
Authority: US
Inventors: T Onarheim; P Solberg
Original assignee: Stord Bartz Industri AS
Current assignee: Stord Bartz Industri AS
Priority date: 1970-05-16
Filing date: 1971-05-11
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02
Also published as: DE2124010C3; CS247051B2; DE2124010A1; NL164657B; GB1313126A; NL164657C; NL7106766A; NO122742B; IE35195L; DE2124010B2; FR2091660A5; YU120771A; YU33220B; SE359370B; PL73338B1; CA934747A; DK125494B; IE35195B1

Abstract

This invention has reference to heat exchangers for the indirect heating, drying or cooling of more or less moist, solid or semisolid materials and which comprise a stationary heat exchanger jacket within which a heat exchanger body is mounted for rotatable movement, said body comprising a hollow cylinder provided with a row of outwardly projecting annular disc-like hollow bodies for receiving a suitable heat exchanger carrier medium and vane means on the hollow bodies for conveying the material to be treated through the chamber and for turning and stirring about this material. An essential feature of the invention involves interconnecting the hollow bodies at the periphery of the hollow cylinder to form a row in series, or two separate rows in series, connected in series with a through-passage of the hollow cylinder and having a flow path extending peripherally forwards and backwards between a medium intake and a medium discharge located at the periphery of the hollow cylinder.

Description

United States Patent 11 1 Onarheim et al.

Apr. 2, 1974 HEAT EXCHANGES [75] lnventors: Thor Onarheim, Hop; Per Solberg, Primary Exammer Albert Bergen, both of Norway [73] Assignee: Stord Bartz lndustri A/S, Bergen, [57] ABSTRACT Norway This invention has reference to heat exchangers for [22] Filed: May 11 1971 the indirect heating, drying or cooling of more or less moist, solid or semi-solid materials and which com- [21] Appl. No.: 142,314 prise a stationary heat exchanger jacket within which a heat exchanger body is mounted for rotatable move- F ment, said body comprising a hollow cylinder pro- [30] orelgn Apphcauon Pnonty Data vided with a row of outwardly projecting annular disc May 16, Norway hollow bodies for receiving a Suitable heat changer carrier medium and vane means on' the holg% g 165/92 165/ 5 3 low bodies for conveying the material to be treated 1 [Pt- ..F 8 through the chamber and for turning and Stirring [58] Field of Search 165/92, 87, 88, 86; About this material An essential feature of the inventlon involves [56] References Cited interconnecting the hollow bodies at the periphery of UNITED STATES PATENTS the hollow cylinder to form a row in senes, or two separate rows in series, connected in series with a 1,656,790 l/1928 HeubCl'lSbjOld 165/90 through passage of the hollow cylinder and having a g igi l flow path extending peripherally forwards and 30066l0 10/1961 i z 125/89 backwards between a medium intake and a medium 3:426:838 2/1969 Onarheim 1. 165/87 j located a the periphery of the hollow c 1n er. FOREIGN PATENTS OR APPLICATIONS y 256,037 5/1963 Australia 165 92 8 Claims 12 D'awmg f' N 23 F f 2s; 22 20 v 34 3s 36 25 HEAT EXCHANGES This invention relates to heat exchangers for the indirect heating, drying or cooling of more or less moist, solid or semi-solid materials, such as solid substances in fluid, or pasty and powdered substances.

Hitherto, a conventional heat exchanger for the afore-mentioned applications has been of the transport screw type, which, inter alia, is described in German Patent Specification No. 969,502. The rotatable heat exchanger body which is employed in the heat exchanger according to the invention is not of the transport screw type, but is on the other hand of the annular disc type-which is described in Norwegian Patent Specification No. 95,490.

A heat exchanger of the transport screw type this is either of the single screw or multi-screw type has the essential deficiency with respect to heat transfer conditions that the amount of material which is to be transported is determined by the number of revolutions per minute of the screw or the screws.

A heat exchanger of the annular disc type, on the other hand, does not provide any positive transport in the axial direction of the substance by means of the annular discs, but conversely brings about a braking of the material during transport in the axial direction. The transport of the substance in the axial direction in a heat exchanger of the annular disc type is effected by means of vanes which are fixed to the annular discs. The vanes are preferably adjustable in order to regulate the transport of the material in the axial direction. If desired, the vanes can be adapted to produce a combined stirring about and transport on turning of the heat exchanger body in a first direction, while on tuming the heat exchanger body in the opposite direction they produce a stirring about without transport in the axial direction.

The heat exchanger according to the invention is adapted to be operable continuously or batch-wise, all according to need and dependent on the adjustment of the turning of the heat exchanger body.

With the present invention the aim is to be able to select a speed of revolution which gives the optimum heat transfer coefficient. Such an optimum heat transfer coefficient is intended to be maintained in instances where there is little substance flow-through in the heat exchanger too. The flow of the substance through the heat exchanger is made possible by the presence of a liberally large passage for the substance between the outer periphery of the rotating heat exhcanger body and the surrounding heat exchanger housing. The mixing of the substance and an extensive stirring of the substance is effected by means of the said vanes, and these movements can be regulated by exclusively regulating the speed of revolution of the heat exchanger body. In addition, the transport of the substance can be regulated in the axial direction of the heat exchanger by altering the direction of rotation of the body of the heat exchanger.

in Norwegian Patent Specification No. 95,490, there is disclosed a dryer in which the heat medium consists of a condensing steam. in the present invention, the aim is, on the other hand, to utilise another heatsupporting medium, preferably a fluid as a heat medium, and a fluid as a cooling medium. It is especially useful to utilise organic heat carriers such as hot oils and inorganic heat carriers such as molten salts, but it can also be worth-while to use other suitable liquids or gases. The special aim is a medium in which safety measurs by dimensioning and the like can be avoided, which are required on the use of saturated steam or like mediums which operate with a substantial excess pressure.

With the present invention there is the further aim of being able to utilise a heavily concentrated heating surface. The main portion of, or the all-predominant portion of, the combined heating surface in the heat exchanger can be concentrated to the rotatable heat exchanger body so as to obtain thereby an especially large heat transfer between the rotatable portion of the heat exchanger and the substance which is to be heated or cooled down. The present invention is thus mainly directed to solutions concerning the rotatable heat exchanger body.

By utilising the afore-mentioned arrangement for the heat exchanger body, there is obtained large flexibility on operation with the possibility of effecting precise regulation of the temperature of the substance and obtaining a heat transfer coefficient which is far better than with known heat exchangers for the same purpose.

With the present invention, the intention is to produce a solution in which the heat supply to, or the heat withdrawal from, the heat exchanger body can occur in an especially effective manner by means of an actual heat carrier or cold carrier which is caused to circulate through the heat exchanger body. Among other things, the aim on starting up is to drive out the collections of air in the heat exchanger body.

According to the present invention a heat exchanger for the indirect heating, drying or cooling of more or less moist, solid or semi-solid materials comprises a stationary, substantially horizontal, heat exchanger jacket defining a chamber within which a heat exchanger body is mounted for rotatable movement, said body comprising a hollow cylinder provided with a row of outwardly projecting annular, disc-like hollow bodies for receiving a suitable heat exchanger carrier medium, and vane means on the hollow bodies for conveying the material to be treated through said chamber axially of said hollow cylinder and for turning over and stirring about said material, said hollow bodies being interconnected at the periphery of said hollow cylinder to form a row in series, or two separate rows in series, connected in series with a through-passage of said hollow cylinder and having a flow path extending peripherally forwards and backwards between a medium intake and a medium discharge located at the periphery of the hollow cylinder.

By arranging the hollow spaces of the hollow bodies in series with the through-passage through the hollow cylinder, a controlled flow through the whole heat exchanger body can be ensured, and in combination with the forwardly and backwardly extending flow in the hollow spaces of the hollow bodies, a controlled and effective flow movement along the heat transferring surfaces of the hollow bodies can be ensured.

A constructionally preferred solution consists in forming the forwardly and backwardly extending flow path in each of the hollow spaces of the hollow bodies by means of a guide plate which extends, preferably axially parallel, from the periphery of the hollow cylinder between the medium inlet and the medium outlet, 21 first section radially outwards from the periphery of the hollow cylinder and a second section substantially concentrically about the hollow cylinder in a curve of more than 180 over towards a separating wall, known per se, disposed radially from the periphery of the hollow cylinder to the periphery of the hollow body.

Furthermore, it is preferred that the hollow bodies are connected to each other via ducts formed externally in the hollow cylnder, for example by welding a half pipe cross-section axially parallel to the periphery of the hollow cylinder.

An effective utilisation of the hollow space of the hollow cylinder is achieved by placing the medium inlet and medium outlet of each hollow body tightly up to the separating wall of the hollow body, and placing the medium inlet and the medium outlet on their respective sides of an axial plane through the hollow cylinder, and tightly up to said first piece of the guide plate.

In order to be able to combine the afore-mentioned features in a constructionally advantageous manner, provision is made for angularly displacing two adjacent hollow bodies with separating walls and guide plates by an arc corresponding to that between the axes of the medium inlet and the medium outlet in one and the same hollow body.

In a heat exchanger where the hollow cylinder is provided with hollow bodies coupled in series in a row, and especially in longitudinal heating bodies, it is important that a flow-through of medium is obtained within the hollow cylinder too. In such a heat exchanger the through-passage of the hollow cylinder from the discharge of the last hollow body in the row of hollow bodies at the one end of the hollow cylinder to the other end of the hollow cylinder, extends in an outer conduit between the hollow cylinder and an internal conduit received in the latter and further backwards in the inner conduit, the supply to the hollow cylinder and the discharge from the hollow cylinder being formed at opposite ends of the hollow cylinder by means of hollow journals known per se.

In a heat exchanger where the hollow cylinder is provided with two separate rows of series-coupled hollow bodies, and where the heat exchanger body is especially designed for gradual or step-wise heating or cooling down of the substance in the heat exchanger, the hollow cylinder and the row of hollow bodies are divided across in two sections having separate flow paths for the circulation of two heat or cold carrier mediums of different temperature.

On clogging" which, for one thing, comprises a heat treatment of various carbohydrate-containing types of meal, for feeding furred animals, it is important to be able to cool the paste mass obtained thereby as quickly as possible after clogging from a temperature of about 100C down to 4C. At the one end of the heat exchange water can be circulated, and the return water can be used for another purpose. A return water of, for example, 90-100C can be used as an additive to the meal for clogging, so that the need for heat is thereby very small in the clogging process itself. At the other end of the heat exchanger there can be employed a suitably cooled down fluid, for example, brine at l.

A heat exchanger for the afore-mentioned purpose and having two separate sections, is preferably constructed so that the disc-shaped hollow bodies of both sections are adapted to have the carrier mediums passed through in one and the same direction axially of the hollow cylinder, and preferably axially opposite to the direction of movement of the material to be treated in the heat exchanger from the inlet to the outlet of the latter.

In order that the invention can be more clearly understood, convenient embodiments thereof will now be described, by way of examples, with reference to the accompanying drawings, in which:

FIG. 1 is a simplified axial section through a heat exchanger according to a first embodiment of the invention,

FIG. 2 is a section along the line IIII of FIG. 1,

FIG. 3 is a perspective view of the body of the heat exchanger, with the one side plate on the annular discshaped hollow bodies removed,

FIG. 4 is an axial section of a heat exchanger body according to an alternative embodiment,

FIG. 5 is a section through a heat exchanger having two separate heat exchanger bodies.

FIGS. 6a, 6b and 6c are enlarged fragmentary views of a first example of a vane system according to the invention illustrated respectively with and Without a transport ability in the axial direction.

FIGS. 7a, 7b, 7c are enlarged fragmentary view of another example of a vane system according to the invention illustrated respectively with and without a transport ability in the axial direction, and

FIG. 8 is a schematic elevation of a circulation system in the heat exchanger housing proper.

Referring to FIGS. 1 to 3, the heat exchanger comprises a stationary, approximately horizontal housing 10 which together with two end gables ll define the substance chamber 12 of the heat exchanger. At the one end of the housing is a substance feed 13 and at the opposite end a substance discharge 14 with an adjustable overflow 15 (FIG. 2). The heat exchanger is designed for continuous treatment (drying or cooling) and the material is conveyed continuously in and through and out of the substance chamber and has, in general, an axial flow through the chamber, with a direction of flow which is preferably directed opposite to the direction of flow of the heating or cooling medium through the heat exchanger, as this is usually preferred. Within the substance chamber 12, there is rotatably arranged a heat exchanger body 16 which is driven in a manner known per se by a motor 17 via a suitable transmission which can comprise a speed regulator (not shown). The body 16 is provided at the one end with a hollow shaft journal 18a which can form the inlet for the heating and cooling medium to the heat exchanger body and which is rotatably mounted in a bearing 19a at the one end of the housing 10. At the other end, the body 16 is provided with another hollow shaft journal 18b which can form the outlet for the heating and cooling medium on the heat exchanger body and which is rotatably mounted in a bearing 19b. The shaft journal 18b can simultaneously constitute the operative journal which is connected to the motor 17. The heat exchanger body 16 comprises a hollow cylinder 20, herein designated generally as a hollow cylinder, to the outer surface of which are welded a row of hollow, annular disc-shaped bodies 21, which herein are designated generally as hollow bodies. These hollow bodies can be produced in a known manner by placing two round plates of slightly conical form and a central opening with two concave sides against each other and thereafter they are welded together along the periphery and along the edge of the central opening welded to the outer surface of the hollow cylinder. In principle the hollow bodies are designed as is described in Norwegian Patent Specification No. 95,490, the only difference being that instead of being joined parallel to the common heat medium-carrying hollow cylinder, they are joined mutually in series and in series with a through-passage in the hollow cylinder 20.

From FIG. 1, it is evident, as shown by the arrows 22, that the heating or cooling medium flows into the ho]- low cylinder of the heat exchanger body 16 through the hollow shaft journal 18a and is led by means of a separating wall-forming plate 23 via an opening 24 in the hollow cylinder 20 inwards into the hollow space of a first hollow body 21 in the row of hollow bodies and is led by means of external ducts 25 on the hollow cylinder in series from hollow body to hollow body. The ducts are formed of half pipe cross-section which are welded to the hollow cylinder and the adjacent hollow bodies. From the last hollow body in the series of hollow bodies, the medium is led, via an opening 26, back to the hollow cylinder.

From FIGS. 2 and 3, it is evident that the medium in the hollow space of the hollow body flows from an intake opening 27 from a duct 25 at the periphery of the hollow cylinder into a radial outer duct 28 and is curved to a radial inner duct 29 from which the medium leaves the hollow body through a discharge opening 30 at the periphery of the hollow cylinder and is transferred via a duct 25 to the following hollow body. The hollow space of the hollow body is divided by means of a separating wall-forming plate 31, which extends radially outwards from the periphery of the ho]- low cylinder in an axial plane to the inner region of the hollow body 21. The outer duct 28 is bounded between opposite sides of the separating wall 31 and side walls of the hollow body and a guide plate 32, which first extends from the periphery of the hollow cylinder a distance radially outwards about one-third of the radial dimension of the hollow body and thereafter is curved in an arc through approximately 270 to the separating wall-formin g plate. The plate 32 extends axially parallel to the hollow cylinder. The inner duct 29 is formed correspondingly between inner walls of the hollow body, the guide plate 32 and the periphery of the hollow cylinder and is bounded at the ends by the rear side of the separating wall-forming plate 31 and the inner side of the oppositely directed guide plate 32. It is evident that the inner end of the plate 32 is disposed between the intake opening 27 and the discharge opening 30 tightly up to them, while the separating wall-forming plate 31 is disposed tightly up to the opposite side of the intake opening 27. From FIGS. 2 and 3, it is evident that adjacent hollow bodies with the

plates

31 and 32 are angularly displaced relative to each other by an arc corresponding to the axial distance between the intake opening and the discharge opening in one and the same hollow body. Provision is made for the ducts 25 to be distributed in a screw line distributed uniformly round the hollow cylinder so as to provide thereby a symmetrical and well balanced turning system.

From FIG. 3, it is further evident that the medium is led first outwards to the periphery of the hollow body with the same direction of flow, shown by arrows 220, as the direction of rotation of the heat exchanger body 16, as shown by the arrow 33. By this, the aim is to reduce the loss of flow of fluid through the heat exchanger, while in the inner duct 29, where the centrifugal forces assert themslves to a lesser extent, the flow of medium passes as shown by the arrows 22b oppositely to the direction of rotation 33 of the hollow body. With the selected duct and flow system, there is obtained, during the starting up of the heat exchanger, the beginning of the filling of the individual hollow body from the outer edge and the filling is effected step-wise from hollow body to hollow body. The speed of rotation can be selected so that the centrifugal acceleration is greater than the acceleration of gravity so that thereby the enclosed air can be driven out of the individual hollow body and, in turn and order, out of each hollow body.

From the opening 26, the medium flows in an outer duct 34, formed between the inner walls of the hollow cylinder and the outer walls of an internal pipe 35 which communicates with the discharge 18b, over to the separating wall-forming plate 23 and is curved so as to flow back to the discharge 18b through an inner duct 36 formed internally in the pipe 35. The pipe 35 is supported at the inner end by means of strut 37 with associated fluid passages between the

ducts

34 and 36.

In the illustrated embodiment, there is shown communication between the hollow bodies externally on the hollow cylinder, but communication will also be possible between the hollow bodies internally in the hollow cylinder, for example by means of pipe connections (not shown). The maximum distance between opposite conically shaped plates of the hollow body can be fixed according to need within a range of for example l to 20 cm, so as to adjust thereby the hollow crosssection of the hollow body according to the amount of fluid which is to be used for heating or cooling the substance in the heat exchanger, so as to obtain thereby an optimum heat transfer coefficient.

In FIG. 4, there is shown a heat exchanger body 40 of corresponding shape to the hollow bodies illustrated in FIGS. l-3. Instead of a row of series-coupled hollow bodies, there are shown two separately series coupled

rows

41, 42 of hollow bodies in their respective heat exchanger system which operate at their respective distinct temperature region. The two systems are internally separated in the hollow cylinder by means of a separating wall-forming plate 43, so that there is formed a first hollow cylinder section 44 to the right of the drawing and a second hollow cylinder section 45 to the left of the drawing, provided with their respective associated

rows

41 and 42 of hollow bodies.

The first hollow cylinder section 44 is supplied its medium at one end of the heat exchanger through an outer duct 46 in the intake 47 to a short chamber 48 and further radially outwards through an opening 49 to the adjacent hollow body. From the end of the row of hollow bodies, the medium is led back to the section 44 through an opening 50 to an elongated chamber 41 and via an inner duct 52 in the intake 47 in return from the heat exchanger.

The second hollow cylinder section 45 is supplied its medium at the associated other end of the heat exchanger through an inner duct 53 to an elongated chamber 54 and via an opening 55 to a hollow body just by the first hollow cylinder section 44. From the end of the row of hollow bodies, the medium is led back to the section 45 through an opening 56 to a short chamber 57 and via an outer duct 58 in the intake in return from the heat exchanger.

The heat exchanger according to FIG. 4 is adapted to effect the heating and cooling respectively in two stages in one and the same heat exchanger, there being supplied a fluid or another medium of different temperature in the two said heat exchanger systems. In the illustrated embodiment, the two systems of the heat exchanger are designed in equally large half portions of the heat exchanger body, but according to need the two systems can be designed with heat exchanger body portions of different size. for example with three hollow bodies in the one system and with seven hollow bodies in the other system.

In FIG. 5 there is illustrated a heat exchanger having two parallel

heat exchanger bodies

60, 61 in one and the same heat exchanger housing. The hollow bodies of the heat exchanger bodies are placed between each other in the intermediate hollow space. From the top of the heat exchanger housing, fixed scraper bars 62 project obliquely downwards to the hollow cylinder of the heat exchanger bodies in the intermediate spaces between the hollow bodies which in a known manner provide for a desired overturning of the material in the intermediate spaces between the hollow bodies. Such scraper bars can be arranged in each of the hollow spaces between the hollow bodies.

At the periphery of the hollow bodies, there are fixed radially outwardly projecting vanes 63, for example four vanes on each hollow body. The vanes 63 project inwards into the intermediate spaces between the hollow bodies on the adjacent heat exchanger body so as to provide an extra turning over of the material in these intermediate spaces and an overturning of the material on the passage of the vanes of the adjacent heat exchanger body and the said fixed scraper bars 62 respectively.

In FIG. 6a, there is illustrated a vane portion 63 which is not designed to produce a forward feeding of the material in the heat exchanger housing, but exclusively for turning over and stirring about of the material in the heat exchanger housing. Such vane portions can be arranged on certain of the row of hollow bodies according to need. The vane portion 63 consists of an angle iron the angle point-forming edge 64 of which is disposed extending radially outwards from the hollow body and the angle legs 65 of which are disposed symmetrically about the central radial plane of the hollow body 21. The vane 63 can be extended inwards on the hollow body and can be welded to the hollow body in a manner not shown further.

In FIG. 611, there is illustrated a

vane

63, 66 consisting of a welded vane portion 63 corresponding to the vane 63 in FIG. 6a, and a detachable vane portion 66. The vane portion 66 consists of a corresponding angle iron to the vane portion 63 and the vane portions are secured by means of screw connections 67 which are fixed in the abutting angle legs. On turning in the direction of the arrow 68 the material is given an axial movement in the direction of the arrow 69. On turning in a direction opposite to the arrow 68, on the other hand, the material is given a minimal movement in the axial direction, which does not have any significance in practree.

In FIG. 6c, the vane portion 66 is fixed to the opposite angle leg of the vane portion 63 so that on turning in the direction of the arrow 68, there is obtained an axial movement of the material in the direction of the arrow 70.

In FIG. 7a, there is illustrated a T-shaped vane portion 71 with the central stem 72 placed in the radial plane of the hollow body and the transverse stem 73 placed across the radial plane. The vane portion 71 can be used in a manner corresponding to the vane portion of FIG. 6a as a simple vane without axial forward feeding, and as a support for another vane portion consisting of an inclined plate 75 having a supporting stem 76 and fixing screws 77 for securing to the vane 71. In FIG. 7b, the vane portion is fixed so that it gives an axial feeding in the direction of the arrows 69 while, in FIG. 70, it gives an axial feeding in the direction of the arrow 70.

In FIG. 8, there is schematically illustrated a zig-zag shaped flow path for the heating medium and the cooling medium respectively in the casing of the heat exchanger housing, with a curved path along the periphery from side to side as indicated by full lines 80 and chain lines 81 with turning points 82, 83 alternately on the front side and the back side of the heat exchanger. The inlet of medium is shown at 84 while the outlet of medium is shown at 85.

Instead of the illustrated through-flow path with one and the same medium, there can be used in a manner corresponding to that shown in FIG. 4 for the heat exchanger body, two separate flow systems in their respective sections of the heat exchanger, with corresponding temperature differences in the two separate flow mediums.

What we claim is:

1. In a heat exchanger for effecting indirect heat transfer to and from moist solid and semi-solid materials which comprises a stationary substantially horizontal heat exchanger jacket; a heat exchanger body; said jacket defining a chamber within which said body is mounted for rotatable movement, said body comprisng a hollow cylinder, a row of radially projecting annular, disc-like hollow bodies mounted on said hollow cylinder for receiving a suitable heat exchange medium; and vane means on said hollow bodies for conveying the material to be treated through said chamber axially of said hollow cylinder and for turning over and stirring about said material; the improvement comprising each said hollow body being communicatively interconnected with an adjacent body at the exterior periphery of said hollow cylinder to form an in series flow course through all said hollow bodies, each said hollow body having internal duct means for directing heat exchanger medium flow therein radially outwardly and inwardly between a medium intake and a medium discharge associated -with such hollow body and located at the exterior periphery of the hollow cylinder whereby the medium courses a flow path in such hollow body partly in and partly counter to the direction of rotation of said heat exchanger body, said hollow cylinder enclosing a through-passage, the flow course through said hollow bodies being connected in series with said through-passage, the duct means in each hollow body including a guide plate with the aid of which the flow path is formed, said guide plate extending from the periphery of the hollow cylinder between the medium intake and the medium discharge, a first section being disposed radially outwards of said periphery and a second section being arranged in an arc of more than l80 substantially concentrically of said cylinder over towards a separating wall located radially beween the periphery of the hollow cylinder and the periphery of the hollow body.

2 The heat exchanger according to claim 1, wherein the guide plate is disposed axially parallel to the hollow body.

3. The heat exchanger according to claim 1, wherein the medium intake and the medium discharge are each disposed on respective sides of an axial plane through the hollow cylinder and tightly up to the first section of the guide plate.

4. The heat exchanger according to claim 1, wherein two adjacent hollow bodies having the separating walls and guide plates are angularly displaced by an arc corresponding to that between the axes of the medium intake and medium discharge in one and the same hollow body.

5. In a heat exchanger for effecting indirect heat transfer to and from moist solid and semi-solid materials which comprises a stationary substantially horizontal heat exchanger jacket; a heat exchanger body; said jacket defining a chamber within which said body is mounted for rotatable movement, said body comprising a hollow cylinder, a row of radially projecting annular, disc-like hollow bodies mounted on said hollow cylinder for receiving a suitable heat exchange medium; and vane means on said hollow bodies for conveying the material to be treated through said chamber axially of said hollow cylinder and for turning over and stirring about said material; the improvement comprising each said hollow body being communicatively interconnected with an adjacent body at the exterior periphery of said hollow cylinder to form an in series flow course through all said hollow bodies, said hollow bodies being inteconnected by interconnecting duct means arranged externally on the hollow cylinder, which interconnecting duct means is defined beween the periphery of the hollow cylinder and a C-shaped member having in cross-section a major dimension less than the diameter of the hollow cylinder and disposed axially parallel to the periphery of the hollow cylinder, each said hollow body having internal duct means for directing heat exchange medium flow therein radially outwardly and inwardly between a medium intake and a medium discharge associated with such hollow body and located at the exterior periphery of the hollow cylinder whereby the medium courses a flow path in such hollow body partly in and partly counter to the direction of rotation of said heat exchanger body, said hollow cylinder enclosing a through-passage, the flow course through said hollow bodies being connected in series with said through-passage.

6. The heat exchanger according to claim 5, wherein the hollow cylinder has two separate rows of seriescoupled hollow bodies formed by dividing said cylinder transversely into two sections with separate flow paths for the circulation of carrier mediums at different temperatures.

7. The heat exchanger according to claim 6, wherein the hollow bodies of both sections are adapted to have the carrier mediums passed through in one and the same direction axially of the hollow cylinder.

8. The heat exchanger according to claim 7, wherein the carrier medium is conveyed in a direction axially opposite to the direction of movement of Y the material to be treated in the heat exchanger from the inlet to the outlet of the latter.

Claims

1. In a heat exchanger for effecting indirect heat transfer to and from moist solid and semi-solid materials which comprises a stationary substantially horizontal heat exchanger jacket; a heat exchanger body; said jacket defining a chamber within which said body is mounted for rotatable movement, said body comprisng a hollow cylinder, a row of radially projecting annular, disc-like hollow bodies mounted on said hollow cylinder for receiving a suitable heat exchange medium; and vane means on said hollow bodies for conveying the material to be treated through saiD chamber axially of said hollow cylinder and for turning over and stirring about said material; the improvement comprising each said hollow body being communicatively interconnected with an adjacent body at the exterior periphery of said hollow cylinder to form an in series flow course through all said hollow bodies, each said hollow body having internal duct means for directing heat exchanger medium flow therein radially outwardly and inwardly between a medium intake and a medium discharge associated with such hollow body and located at the exterior periphery of the hollow cylinder whereby the medium courses a flow path in such hollow body partly in and partly counter to the direction of rotation of said heat exchanger body, said hollow cylinder enclosing a through-passage, the flow course through said hollow bodies being connected in series with said throughpassage, the duct means in each hollow body including a guide plate with the aid of which the flow path is formed, said guide plate extending from the periphery of the hollow cylinder between the medium intake and the medium discharge, a first section being disposed radially outwards of said periphery and a second section being arranged in an arc of more than 180* substantially concentrically of said cylinder over towards a separating wall located radially beween the periphery of the hollow cylinder and the periphery of the hollow body. CM,2Eat exchanger according to claim 1, wherein the guide plate is disposed axially parallel to the hollow body.

6. The heat exchanger according to claim 5, wherein the hollow cylinder has two separate rows of series-coupled hollow bodies formed by dividing said cylinder transversely into two sections with separate flow paths for the circulation of carrier mediums at different temperatures.

8. The heat exchanger according to claim 7, wherein the carrier medium is conveyed in a direction axially opposite to the direction of movement of the material to be treated in the heat exchanger from the inlet to the outlet of the latter.