US3590899A

US3590899A - Rotor construction of thin film treatment apparatus

Info

Publication number: US3590899A
Application number: US854150A
Authority: US
Inventors: Adolf Ulrich Liechti; Ulrich Kaspar Zbinden
Original assignee: Luwa Ltd
Current assignee: Luwa Ltd
Priority date: 1968-09-11
Filing date: 1969-08-29
Publication date: 1971-07-06
Anticipated expiration: 1988-07-06
Also published as: DE1940722B2; NL6913777A; DE1940722C3; JPS4918350B1; CH496934A; AT314478B; GB1266165A; SE345227B; FR2017762A1; BE738085A; DE1940722A1

Abstract

There is disclosed a rotor for a thin film treatment apparatus which incorporates a central tubular body and a number of axially and radially extending rotor blades arranged about the periphery thereof. The edges of the rotor blades confronting the tubular body possess connection tongues, or equivalent structure, which are connected, for instance by welding, with the surface of the tubular body. According to an important aspect of the invention at least a part of the connection tongues, externally of the planes containing the side surfaces of the associated rotor blades are connected with the tubular body, and further, the rotor blades exhibit invented spaces arranged spaced from one another in the lengthwise direction. More specifically, these indented spaces extend centripetally over a portion of the radial width of the associated rotor blade from the lengthwise extending edge of such rotor blade facing away from the tubular body.

Description

United States Patent Mellott 159/6 WH Metcalfe-Shaw 127/28 X Zahm 159/6 W Latinen etal... lS9/6W Goosens 159/6 W X Primary Examiner-Norman Yudkoff ABSTRACT: There is disclosed a rotor for a thin film treatment apparatus which incorporates a central tubular body and a number of axially and radially extending rotor blades arranged about the periphery thereof. The edges of the rotor blades confronting the tubular body possess connection tongues, or equivalent structure, which are connected, for instance by welding, with the surface of the tubular body. According to an important aspect of the invention at least a part of the connection tongues, externally of the planes containing the side surfaces of the associated rotor blades are connected with the tubular body, and further, the rotor blades exhibit invented spaces arranged spaced from one another in the lengthwise direction. More specifically, these indented spaces extend centripetally over a portion of the radial width of the associated rotor blade from the lengthwise extending edge of such rotor blade facing away from the tubular body.

[72] Inventors Adolf Ulrich Liechti 1,576,838 3/1926 Muri; 2,024,299 12/1935 Ulrich Kaspar Zbinden, Zurich, both of, 2,542,270 2/1951 Switzerland 3,067,812 12/1962 [21] Appl. No. 854,150 3,311,457 3/1967 [22] Filed Aug. 29, 1969 22:25:: 332k? Assistant Examiner-.1. Sofer [32] Priority Sept. 11, 1968 ArrorneyWemer W. Kleeman 3 3 1 Switzerland 31 13,603/68 [54] ROTOR CONSTRUCTION OF THIN FILM TREATMENT APPARATUS 12 Claims, 7 Drawing Figs.

[52] U.S.C1. 159/6 W, 159/ 13 [51] Int. Cl B01d1/22 [50] FieldofSearch 159/6 W,6 WH; 202/236, 89; 29/150, 15, 156.8 B, 157.3 B, 400, 455, 470, 471.3

[56] References Cited UNITED STATES PATENTS 1,308,819 7/1919 Taylor 159/6 WH 12 8 Js 4 /P\ 32 -5 L 28 2o a f T T I I -f" 30 1 30 V J 70 26 E 3s J big-O 32 PATENTEU JUL sum 9599.999

g 7 INVENTOR BYM W ROTOR CONSTRUCTION OF THIN FILM TREATMENT APPARATUS BACKGROUND OF THE INVENTION The present invention broadly relates to thin film treatment apparatus and, more specifically, deals with an improved rotor construction for such a thin film treatment apparatus.

A known physical construction of rotor for thin film treatment apparatus consists of a central tubular body which is rotatably supported at its ends in the housing of the treatment apparatus. A drive shaft is coupled with one end of the central tubular body. Further, a plurality of rotor blades which are spaced about the periphery of the rotor body extend in the lengthwise direction thereof. These rotor blades generally protrude radially from the rotor body, the radially disposed lengthwise edges of such blades serving to distribute or wipe the material to be treated in a thin layer upon the generally cylindrical inner wall of the apparatus of the housing. The rotor blades are flushly connected by welding with the tubular body along their radially inwardly disposed edges. Even though the general construction of such rotors is relatively simple, still, the costs of manufacturing same is nonetheless quite expensive. First of all, the rotor blades must be welded at the edges neighboring the tubular body along the entire length at the outer or peripheral surface thereof. This is necessary in order to fill the gap therebetween, and specifically, to prevent any penetration of treatment material into this gap. Even though accessibility to the welding seams is quite difficult these welding seams must nonetheless be produced such that they are practically free of pores, and this operation is correspondingly expensive.

A rotor construction is also known to the art in which the rotor blades are welded through the agency of connection tongues with the tubular body. In this arrangement, the radially inwardly directed edge portions of the rotor blades disposed between the connection tongues are spaced from the surface of the tubular body. Hence, the expenditure of labor during welding of rotor blades to the tubular body is much less, since the welding seams are appreciably shorter. Although treatment material can indeed penetrate into the slots between the surface of the tubular body and the edges of the rotor blades confronting such tubular body, still, cleaning of the slots is readily possible since they possess a certain width. In the known constructions of rotors, of the type wherein the rotor blades are welded with the tubular body through the agency of connection tongues, one particular difficulty is readily noticeable, which basically, is also present in rotors in which the rotor blades are welded throughout their entire length with the tubular body. Specifically, the stresses which result in the rotor blades during operation, and which can assume quite considerable values during wiping of viscous media at the treatment wall, reach their maximum at the attachment locations, that is to say, at those cross-sectional regions in which these rotor blades are welded with the tubular body. The welding seams are therefore subjected to pronounced loads. The same is also true for the cross-sectional region of the rotor blades which directly neighbor the welding seams, the joints of which sometimes are changed in an unfavorable way due to the welding operation and exhibit a reduced strength.

SUMMARY OF THE INVENTION Therefore, there is a real need in the art for a rotor construction which overcomes the aforementioned drawbacks of the prior art structures. Accordingly it is a primary object of the present invention to provide an improved rotor construction for thin film treatment apparatus which effectively overcomes these prior art disadvantages.

Yet, another more specific object of the present invention relates to an improved rotor construction having a unique and novel method of attachment of the rotor blades to the rotor body member.

Still a further significant object of the present invention relates to an improved construction of rotor assembly for a thin film apparatus which is relatively simple in construction, can be manufactured at reasonable cost, does not require any complicated or unwieldy manufacturing operations, is ex tremely reliable in operation, and specifically, prevents the occurrence of the problems enumerated above and experienced with the prior art constructions.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, it will be understood that the inventive rotor is of the type incorporating a substantially central tubular body and a plurality of rotor blades arranged at the circumference of such tubular body, these rotor blades extending in the lengthwise direction of said tubular body. Each of the rotor blades possesses a lengthwise extending edge which con fronts the tubular body and possesses connection tongue means, or equivalent structure, connected with the surface of the tubular body. According to an important facet of the in vention, at least a portion of the connection tongue means of the associated rotor blade are connected with the tubular body externally of the planes containing the side surfaces of the associated rotor blade. Moreover, each of the rotor blades possesses cutout portions which are spaced in lengthwise direction from one another and which extend over a portion of the width of the associated rotor blade from the lengthwise extending edge of such associated rotor blade facing away from the tubular body.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood, and objects other than those set forth above, will become apparent, when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawing wherein:

FIG. 1 schematically depicts a longitudinal sectional elevational view of a thin film treatment apparatus equipped with a rotor designed according to a first embodiment of the present invention;

FIG. 2 is a sectional view of the rotor construction depicted in FIG. 1, taken along the line ll-II thereof;

FIG. 3 is an elevational view of a second embodiment of rotor construction according to the invention;

FIG. 4 is a sectional view of the rotor construction depicted in FIG. 3, taken along the line IV-IV thereof; and

FIGS. 5 to 7 inclusive show three different respective forms of rotor blades at their wiper portion.

DESCRIPTION OF THE PREFERRED EMBODIMENT Describing now the drawings, and, more specifically, directing attention to the exemplary embodiment of thin film treatment apparatus, for instance a thin film evaporator, depicted in FIG. 1, it will be recognized that such embodies a housing 2 having an infeed connection or stud 4 for the influx of material to be treated. The treated material leaves the apparatus housing 2 at a substantially funnel-shaped lower portion 6 from where it is withdrawn. The rotor member, generally designated by reference numeral 16, is supported at the stub shafts l2 and 14 in suitable bearing means 8 and 10, respectively. This rotor 16 possesses a substantially centrally arranged cylindrical tubular body member 18 extending coaxially with respect to the stub shafts 12 and I4 and rigidly connected therewith.

About the periphery of the rotor body 18 there are uniformly arranged a number of rotor blades, and in this specific arrangement it will be seen that four such rotor blades 20 are provided. These rotor blades 20 extend in the lengthwise direction of the tubular body member 18 and, further, incorporate blade portions 22 which protrude in the radial direction from the rotor body member. Further, it will be recognized that the lengthwise edges or marginal portions 24 of the blade portions 22 facing away from the tubular body member 18 serve for distributing the treated material upon the generally cylindrical inner wall 26 of the housing 2 of the thin film treatment apparatus. On the other hand, the lengthwise extending edges 28 of the blade portions 22 confronting the tubular body member 18 incorporate or possess

connection tongues

30 and 30 and 32 and 32', respectively. It will be understood that in the context of this application the term connection tongues" is used in its broader sense as describing attachment means, which may be in the form of tongues, tabs, flaps, or the like. Continuing, it will be recognized that these connection tongues 30 and 30' are flexed or bent with respect to the planar or flat blade portion 22 to opposite sides. The same is also true of the

connection tongues

32 and 32. Additionally, it will be seen that a respective pair of these

connection tongues

32 and 32 is provided at each of both ends of a rotor blade 20, whereas the connection tongues 30 and30 are distributively arranged between the ends of the associated blade uniformly over the length of such rotor blade 20. In the embodiment illustrated in FIGS. 1 and 2, it will be observed that one of each such connection tongues 30 and 30' is provided. These

connection tongues

30 and 30 and 32 and 32, respectively, are connected, typically by welding, with the tubular body member 18 along linearly directed and axially parallel edges 34. Furthermore, it should be understood that according to a significant feature of the present invention these edges 34 are situated externally of the planes defining or containing the side faces or surfaces of the blade portions 22. Additionally, it will be seen that cutout portions or grooves 36 are provided at the free lengthwise edges 24 of each of the blade portions 22, these cutout portions 36 being distributively arranged, as shown, over the length of such associated blade portion. More specifically, it will be observed that these cutout portions or indented spaces 36 are, in each instance, located at the region of a connecting tongue 30 and 30', respectively, and further, extend perpendicular to the associated lengthwise blade edge 24 over the width of the blade portion 22, as shown. In fact, such cutout portions can extend up to the root portion of the associated connection tongues 30, 30' as shown at 70.

Now the described physical construction of rotor for the depicted thin film apparatus possesses a number of different notable advantages. First of all, with sufficient flexure or angulation of the connecting

tongues

30 and 30 and 32 and 32', respectively, relative to one another it is possible to displace the cross section in which the greatest stresses occur from the welding edge 34 into the plane of the edges or marginal portions 28, in which the connection tongues transform or merge with the blade portion 22. Consequently, the greatest loading of the rotor blades, fabricated from continuous sheet metal of uniform thickness, occurs at a region or portion which has not experienced any considerable thermal loading by virtue of welding with the tubular body. As a result, the danger of rupture or fissure formation is considerably reduced. Notwithstanding these properties it is only necessary to provide relatively few and short welding seams, in order to secure the rotor blades to the tubular body member I8. Owing to the angulation or bending of the connection tongues there also is provided the notable advantage that the welding edges 34 are readily accessible even when utilizing a relatively large number of blades distributed about the periphery of the tubular body, and therefore the welding seams can be produced relatively easily. It has been found that with the same strength as compared with known constructions the inventive construction enables a saving in material and a reduction in weight.

The relatively deep cutout portions or indented 'spaces 36 provided at the zones of the connecting

tongues

30 or 32 prevent the occurrence of longitudinal stresses at the tubular body 18 due to relatively great expansion of the rotor blades 22 along their free marginal edges 24. The dreaded warping or bending of the tubular body, attributable to the relatively high material temperatures at the region of the treatment wall 26, can thus be faultlessly prevented.

The second embodiment of rotor construction depicted in FIGS. 3 and 4 differs from that shown in FIGS. 1 and 2 primarily in the manner in which the connection tongues or flaps 40 are all of the same construction. Whereas, furthermore, with the embodiment of FIGS. 1 and 2 the

connection tongues

30, 30' and 32, 32' were flexed or bent about an axis parallel to the

lengthwise edges

24 and 28, in this embodiment the connection tongues or flaps 40 are bent out of the plane of the blade portion 42 about an axis extending perpendicular to the lengthwise edges 44. Consequently, the welding seams 46 of the connection tongues or flaps 40 extend upon the outer surface of the tubular body 18 along a helical line. Each connection tongue 40 possesses a portion 40' and a further portion 40", which, with respect to the blade portion 42, extend to opposite sides, in other words are disposed externally of the planes containing the respective side faces or surfaces of the blade portion 42. Hence, the associated portions of the welding edges 46 are also located outside of the mentioned planes. Once again, it will be observed that portions or indented spaces 48, or equivalents, are provided at the blade portion 42 of each blade, these cutout portions, insofar as construction, arrangement and function, corresponding to the cutout portions 36 of the preceding embodiment of FIGS. 1 and 2.

Here also the rotor construction of the embodiment of FIGS. 3 and 4 provides essentially the same advantages as attributed to the embodiment of rotor depicted in FIGS. 1 and 2. Once again, it is possible to especially, here also, considerably reduce the specific loading of the welding seam and welding edges 46, respectively, as well as also the directly neighboring cross section.

Now, turning attention to FIGS. 5, 6 and 7, respectively, here there are shown three different constructional forms of rotor blades or vanes which, basically, can be secured to the associated tubular body 18 in one of the ways shown, for'instance, in the arrangement of FIGS. 1 and 2. Whereas, with the embodiment of rotor blades or vanes depicted in FIGS. 5 and 6, respectively, one is dealing with rotor blades of a rigid construction, in the remaining embodiment of FIG. 7 there is shown a wiper blade 50 which can be pivotably connected through the agency of a suitable hinge or articulation ring member 52 with the rigid portion 54 of the associated rotor blade.

Now, as far as all of these arrangements of rotor blades are concerned, as shown in FIGS. 5 to 7 inclusive, it will be understood that the wiper blade portion 56 of FIG. 5 which is flexed with respect to the rigid blade portion 54, and similarly the wiper blade portion 58 of the blade arrangement of FIG. 6, as well as also the hingedly connected wiper blade portion 50, articulated in FIG. 7 to the rigid portion 54 of the rotor blade by means of the pivotal hinge connection ring means 52, are all subdivided in the lengthwise direction, and specifically, in accordance with the cutouts or

indented spaces

36 and 48 shown in respective FIGS. 1 and 3 heretofore described. It is naturally also conceivable to provide the rigid portions 54 (FIGS. 6 and 7) secured to the tubular body with cutouts or the like, which extend radially up to the tubular body 18 and contribute to reductions in stress at such tubular body 18. It will be seen that such an arrangement of cutout portions or indented spaces which extend up to the root portion of the associated connection tongue means has been shown in phantom lines by reference character 70 in FIG. 1, but could be equally well provided in any of the other embodiments shown herein except that in the arrangement of FIG. 7 the existence of the hinged connection ring means 52 only necessitates that the cutout portions or indented spaces be provided at the blade portion 54 which is rigidly connected with the tubular body.

It should be apparent from the foregoing detailed description, that the objects set forth at the outset to the specification have been successfully achieved. ACCORDINGLY,

What we claim is:

l. A rotor for a thin film treatment apparatus comprising, in combination, a substantially centrally arranged tubular body containing said side surfaces thereof.

means, a plurality of planar rotor blades having side surfaces and secured to the outer circumference of said tubular body means, said rotor blades extending in the axial direction of said tubular body means, each of said rotor blades having an axially extending outer edge and an axially extending inner edge, said axially extending inner edge confronting but radially spaced from said tubular body means and possessing connection tongue means extending toward said tubular body means out of the planar material of the blade and bent laterally in opposite directions out of the plane of the blade and connected at their innermost ends to the surface of said tubular body means, at least a portion of said connection tongue means of the associated rotor blade being connected with said tubular body means externally of the planes containing said side surfaces, said rotor blades further possessing indented spaces which are spacedly separated in the axial direction and which extend over at least a considerable portion of the radial extent of the associated rotor blade from said axially extending outer edge of said associated rotor blade centripetally toward the tubular body means.

2. A rotor for a thin film treatment apparatus as defined in claim I, wherein a weld connection serves to secure said connection tongue means to said tubular body means.

3. A rotor for a thin film treatment apparatus as defined in claim 1, wherein said connection tongue means extend from the associated rotor blade to peripherally spaced places on the tubular body means.

4. A rotor for a thin film treatment apparatus as defined in claim 3, wherein each mutually adjacent pair of connection tongue means are arranged spaced from one another in the axial direction of the associated rotor blade and are angled to opposite sides of the rotor blade.

5. A rotor for a thin film treatment apparatus as defined in claim 3, wherein said connection tongue means are angled with respect to the associated rotor blades out of the planes 6. A rotor for a thin film treatment apparatus as defined in claim 5, wherein each of said indented spaces is located at approximately the position of a connection tongue means along the rotor blade.

7. A rotor for a thin film treatment apparatus as defined in claim 6, wherein each indented space extends up to the root region of the associated connection tongue means.

8. A rotor for a thin film treatment apparatus as defined in claim 3, wherein each connection location of said connection tongue means with said tubular body means extends along a substantially helical line at the surface of said tubular body means.

9. A rotor for a thin film treatment apparatus as defined in claim 8, wherein each of said indented spaces is disposed approximately opposite the location of a connection tongue means.

10. A rotor for a thin film treatment apparatus as defined in claim 9, wherein each indented space extends up to the region of the root portion of the associated connection tongue means.

1]. A rotor for a thin film treatment apparatus comprising, in combination, a substantially centrally arranged tubular body means, at least one rotor blade having side surfaces and first and second opposed longitudinal edges, said rotor blade being secured to the outer circumference of said tubular body means, said rotor blade extending in the axial direction of said tubular body means, said rotor blade having an axially extending edge defined by said first longitudinal edge confronting but radially spaced from said tubular body means and possessing connection tongue means extending toward said tubular body means to peripherally spaced points on the surface of said tubular body means, at least a portion of said connection tongue means of the rotor blade being connected with said tubular body means at said peripherally spaced points on the surface thereof, said rotor blade further possessing indented spaces which are spacedly separated in the axial direction and which extend over at least a portion of the radial extent of the rotor blade from said second longitudinal edge of said rotor blade toward the tubular body means.

12. A rotor for a thin film treatment apparatus as defined in claim 11, wherein said indented spaces extend over at least one-half of the radial extent ofthe rotor blade.

Claims

1. A rotor for a thin film treatment apparatus comprising, in combination, a substantially centrally arranged tubular body means, a plurality of planar rotor blades having side surfaces and secured to the outer circumference of said tubular body means, said rotor blades extending in the axial direction of said tubular body means, each of said rotor blades having an axially extending outer edge and an axially extending inner edge, said axially extending inner edge confronting but radially spaced from said tubular body means and possessing connection tongue means extending toward said tubular body means out of the planar material of the blade and bent laterally in opposite directions out of the plane of the blade and connected at their innermost ends to the surface of said tubular body means, at least a portion of said connection tongue means of the associated rotor blade being connected with said tubular body means externally of the planes containing said side surfaces, said rotor blades further possessing indented spaces which are spacedly separated in the axial direction and which extend over at least a considerable portion of the radial extent of the associated rotor blade from said axially extending outer edge of said associated rotor blade centripetally toward the tubular body means.

2. A rotor for a thin film treatment apparatus as defined in claim 1, wherein a weld connection serves to secure said connection tongue means to said tubular body means.

5. A rotor for a thin film treatment apparatus as defined in claim 3, wherein said connection tongue means are angled with respect to the associated rotor blades out of the planes containing said side surfaces thereof.

6. A rotor for a thin film treatment apparatus as defined in claim 5, wherein each of said indented spaces is located at approximately the position of a connection tongue means along the rotor blade.

11. A rotor for a thin film treatment apparatus comprising, in combination, a substantially centrally arranged tubular body means, at least one rotor blade having side surfaces and first and second opposed longitudinal edges, said rotor blade being secured to the outer circumference of said tubular body means, said rotor blade extending in the axial direction of said tubular body means, said rotor blade having an axially extending edge defined by said first longitudinal edge confronting but radially spaced from said tubular body means and possessing connection tongue means extending toward said tubular body means to peripherally spaced points on the surface of said tubular body means, at least a portion of said connection tongue means of the rotor blade being connected with said tubular body means at said peripherally spaced points on the surface thereof, said rotor blade further possessing indented spaces which are spacedly separated in the axial direction and which extend over at least a portion of the radial extent of the rotor blade from said second longitudinal edge of said rotor blade toward the tubular body means.

12. A rotor for a thin film treatment apparatus as defined in claim 11, wherein said indented spaces extend over at least one-half of the radial extent of the rotor blade.