US3221807A

US3221807A - Apparatus for heat treatment of liquids

Info

Publication number: US3221807A
Application number: US266670A
Authority: US
Inventors: Johansson Bjorn Olow
Original assignee: Separator AB
Current assignee: Alfa Laval Holdings Amsterdam AB
Priority date: 1962-03-23
Filing date: 1963-03-20
Publication date: 1965-12-07
Anticipated expiration: 1982-12-07
Also published as: GB1018977A; SE206743C1

Description

Dec. 7, 1965 B. O. JOHANSSON APPARATUS FOR HEAT TREATMENT OF LIQUIDS Filed March 20, 1965 -46 zhga 25 Cl 23 l8 4/ Z 45 I7 ji 2 l3 l5 9 4261 43 2a 2 L Z 27 zLi 2/ l2 1 I5 Hg. I

INVENTOR. Bj'rn O/ow Johansson 09% 7/; 97m; WW

United States Patent 3,221,s07 APPARATUS FOR HEAT TREATMENT 0F LIQUIDS B10111 Olow Johansson, Lemma, Sweden, assiguor to Aktlebolaget Separator, Stockholm, Sweden, a corporation of Sweden Filed Mar. 20, 1963, Ser. No. 266,670 Claims priority, application Sweden, Mar. 23, 1962, 3,278/ 62 11 Claims. (Cl. 16588) This invention relates to centrifugal apparatus for effecting indirect heat exchange between a liquid and a vapor, and has particular reference to an improved apparatus for this purpose. Centrifugal apparatus of the type to which the present invention relates comprises generally a rotor body having a nest of annular conical disks provided at their outer peripheries with radial flanges which are held together and space the conical areas of the disks from each other, whereby the rotor disks form conical interspaces or channels. Alternate ones of these conical channels serve for passage of the liquid, while the others serve for passage of the vapor. The rotor body is mounted on a shaft and rotated in a stationary casing or housing which may be evacuated by connection to a suction pipe. The alternate conical channels for the liquid open through the radial outer flanges at the periphery of the rotor body into the chamber between the rotor body and the casing, While the remaining conical channels for the vapor communicate through radial passages with an axial passage (that is, a passage generally parallel to the rotor axis) in the radial outer flanges of the rotor body. This axial passage, in turn, communicates with an annular groove located in the rotor body and provided with a stationary paring member for discharging liquid from the groove, the groove opening toward the rotor axis but being otherwise closed and being cut off from communication with the chamber between the rotor body and the casing.

Apparatus of this type, in which the disks forming the conical channels rotate with the rotor, is known in the art. It is characterized by providing large heat exchange surfaces within a very small volume and, due to the rotation, by causing the liquid medium to spread itself in a very thin layer on the entire conical surface over which it flows, whereby the so-called K-value is very high. The apparatus can be used for evaporating or concentrating a liquid by means of a vapor, condensing a vapor by means of a liquid, or increasing or lowering the temperature of a liquid by means of a vapor.

Such apparatus as proposed heretofore, however, has the objections that it is of complex construction and is diflicult to assemble and disassemble incident to cleaning and inspection. Also, such prior apparatus is difiicult to manufacture in providing the passages for leading the two media to and fro-m the conical channels in such manner that the media can, optionally, flow through these channels in unidirectional current or in countercurrent. In either case, due to the action of the centrifugal force, the liquid medium must be admitted to the conical channels at their smallest radius and discharged therefrom at their largest radius.

The principal object of the present invention is to provide an apparatus of the type described which overcomes the above-noted objection to prior apparatus of this type.

In an apparatus made according to the invention, the

conical disks are provided with the radial outer flanges and also with radial inner flanges by means of which the rotor body is mounted on its driving shaft. These inner flanges define an axial passage opening toward one end of the rotor shaft and forming an inlet for one of the two media, this axial inlet passage communicating with the alternate conical channels between the disks. The other conical channels communicate with an inlet duct for the other medium by way of the annular groove provided with the stationary paring member or dis charge device. The inner flanges may also form a second axial passage through which these other conical channels are fed with the other medium from its inlet duct by way of the annular groove. Thus, the latter may serve for feeding these other conical channels through an axial passage in either the inner flanges or the outer flanges of the disks.

The outer flanges of the disks may also have radial passages or an axial passage, or both, leading outside the rotor body from the alternate conical channels.

These and other features of the invention will be described in more detail with reference to the accompanying drawings, in which:

FIG. 1 is a vertical sectional view of a preferred form of apparatus according to the invention, and

FIG. 2 is a horizontal sectional view on line 22 in FIG. 1, with the casing omitted.

The apparatus as illustrated comprises a lower frame part 1 and an upper frame part 2, the latter supporting a housing or casing having a lower part 3 and an upper part 4 connected to each other by means of flanges 5 and 6 which are releasably secured to each other by bolts (not shown). The housing forms an inner closed chamber 7 which is provided with a vapor outlet 8, preferably a suction pipe connected to a suction pump (not shown). A vapor condensate outlet formed by pipe 9 also leads from chamber 7.

A vertical stationary shaft 10, which carries to ball bearings 11 and 12 at its bottom and another ball bearing 13 at its top, is mounted in the frame 12. These ball bearings carry a hollow spindle 14 which is driven through a driving pulley 15 from a driving motor (not shown).

The rotor body comprises a nest of annular conical disks 16 and 17 alternating with each other. The disks 16 and 17 have peripheral

outer flanges

18 and 19, respectively, and

inner flanges

20 and 21, respectively. The inner flanges 2t), 21 fit closely around the hollow spindle 14 and are secured to same by being clamped between a shoulder 22 on the hollow spindle and a nut 23, the

threads 23a of which engage corresponding threads on the hollow spindle.

The

inner flanges

20, 21 and the

outer flanges

18, 19 are provided with axial holes forming

axial passages

24, 25, 26 and 27, there being several of each such passages spaced around the rotor axis. Each axial passage 24 communicates, via radial passages 28 in the inner flanges 20, with the alternate conical channels 29 between the conical disks 16, 17. Each axial passage 26 communicates, via radial passages 26a, with the same conical channels. Likewise, each axial channel 25 in the inner flanges communicates, via radial channels 30 in these flanges, with the other conical channels 29a which, via radial channels 31 in the outer flanges, communicate with the axial channels 27 in the outer flanges. Thus, two series of conical channels are formed, separated from each other, of which alternate conical channel 29 communicate with at least one axial channel in the inner flanges and one axial channel in the outer flanges, while the other conical channels 29a communicate with at least another axial channel in the inner flanges and another axial channel in the outer flanges.

The axial channel or passage 26 opens downwardly into an annular groove 32 arranged at the outside of the rotor body. This groove is open towards the rotor axis and is provided with a stationary paring member 33 which extends through the wall of the housing 3.

The axial channel 27 opens into an annular groove 34 arranged inside the rotor body. This groove opens towards the rotor axis and is provided with a stationary paring member 35 which is secured to part 2 of the frame and communicates with a discharge channel 36 in the frame. A wall 37 of the rotor body and a sealing device 38 held against the frame 2 form a means for sealing the groove 34 from the chamber 7. A slit 39 between the hollow spindle 14 and part 2 of the frame is sealed by means of another sealing device 40.

Sealing elements (not shown) may be fitted between the confronting surfaces of the flanges 19 and in order to seal the conical channels against undesirable leakage.

The uppermost conical disk 16, provided with an inner and an outer flange, is doubled with an extra conical disk 41 which, together with the former one, forms a conical channel 42 communicating at its outer end with the passage 27 and at its inner end through passage 42a with passage 43 in the nut 23. The latter passage communicates, in turn, with a passage 44 in the hollow spindle 14. The inner flange 20 of the uppermost conical disk 16 is not, as are the other inner flanges, provided with a passage hole in order to form an extension of the channel but forms instead a shut-off device for the channel 25 at this end. On the other hand, the same flange 20 is provided with a passage hole forming an extension for the passage 24 which thus communicates with a passage 45 in the nut 23 as well as with another passage 46 in the hollow spindle 14. The hollow spindle 14, which rotates during operation, has its

passages

44 and 46 connected through a sealed flow connection 47 with stationary ducts 48 and 49, respectively, on the housing 4.

The radial passages 28 open into annular grooves 50 on the outside of the inner flanges 20 in the conical chan nels 29. These grooves are provided with overflow edges 51 leading outward into the conical channels 29. The same conical channels are provided, at the inside of the outer flanges 18, with annular channels 52 into which the radial channels 26a open. Radial through-going channels or passages 54, which open into the chamber 7, are located above the annular channels 52 and separated from the latter by means of an inwardly turned annular projection 53.

The frame 2 has an inlet duct 55 for one of the media. This duct communicates through a passage 56 with the groove 34 and with the axial passage 25. The axial passage 24 is plugged by means of a plug 57 in the lowermost flange 20.

If the apparatus is to be used to evaporate and concentrate a liquid by means of a vapour, a suction device is preferably connected to the outlet pipe 8 so that the evaporation can be carried out under vacuum. In this case the vapour is admitted through the inlet 55 and is led up into the axial passage 25, from which. it spreads through the radial passages into the conical channels 29a. The walls of these channels receive heat from the vapour and condense it more or less. The condensate is discharged through the radial passages 31 and collected into the axial passage 27, from which it is discharged into the groove 34 where it is pared off by the paring member and discharged through the channel 36. Air or other uncondensable gas contained in the vapour rises in the passage 27 and is discharged from the rotor body through the

channels

42, 43, 44 and 48 to atmosphere.

The liquid which is to be evaporated or concentrated is admitted at the same time through the stationary inlet duct 49 and passes through the passages 46 and into the axial passage 24. The liquid is then led through the passages 28 into the annular chambers in the alternate conical channels 29. From these annular chambers the liquid is thrown out centrifugally over the overflow edges 51 against the disks 17 and passes in an evenly spread thin layer over these disks and across the respective conical channels 29 towards their outer peripheries while being evaporated and concentrated by heat transmission from 4 the disks 17. The concentrated liquid is then collected in annular channels 52 and discharged through the radial passages 26a to the axial passage 26 and annular groove 32, from which it is pared out of the casing 3-4 by means of the paring member 33. The secondary vapour, which is liberated from the liquid during evaporation in the conical channels, passes through the radial passages 54 directly into the chamber 7. Any liquid drops carried along with this secondary vapour are thrown against the inner walls of the casing, along which they glide down to the discharge outlet 9. The secondary vapour in the housing 7 is discharged or exhausted through the outlet 8.

In the above-described operation, the liquid and the vapour or steam pass through separate conical channels, both flowing radially outwards in unidirectional currents.

Inorder to obtain a liquid distributioon as even as possible on the disks 17, the upper surfaces of the overflow edges 51 may be provided with radial grooves (not shown). To avoid burning of the liquid by the hot inner flanges, the latter may be lined with a heatinsulating material in the annular chambers 50.

If it is desired to lead the steam in the opposite direction through the conical channels, the lower end of the axial passage 25 is plugged or else the inner flanges are not provided with the holes which form the passage 25 and the passages 30. In that case the vapour passes from the inlet 55 through the passage 56 and the annular groove 34 into the axial passage 27 and from the latter through radial passages 31 into the conical chan nels 2911 where it is cooled and condensed. The condensate returns by way of the same path but is pared off in the groove 34 by the paring member 35. In that case the passages 2'7 and 31 should have a larger crosssection than otherwise, and the paring member 35 with its paring edge should be displaced further outwardly in the radial direction so that the condensate does not obstruct the inflow of vapour to passage 27.

Instead of discharging the secondary vapour through the radial passages 54 in the outer flanges, these passages can be plugged or omitted and replaced by radial or axial passages in the inner flanges, the latter passages being made in the same way as the passages 28 and 24 with the difference that the channels 28 must open above the liquid in the chambers 50.

If the apparatus is to be used only for heating a liquid by means of a vapour or for cooling a vapour to a condensate by means of a liquid, the vapour can be admitted and discharged according to any of the abovedescribed methods. The liquid is then admitted into the conical channels in the same way as just described, but it can be discharged in different days.

According to an alternative, the radial passages 54 are omitted and the liquid is discharged through the

passages

26a and 26, the groove 32 and the paring member 33. The outlets 8 and 9 are then unnecessary, but the outlet 9 can be kept for drainage.

According to another alternative, either the

passages

26a and 26 nor the flange 53 are used and therefore are omitted and only the passages 54 are retained. The liquid is then thrown out directlyinto the chamber 7 through the latter passages and is collected at the bottom of the casing and discharged therefrom through the outlet 9. The outlet 8 is then unnecessary.

If, in the latter case, the liquid is not only to be warmed but also concentrated under vacuum, a suction pump is connected to the outlet 8, which (via the passages 54) produces a vacuum in the conical channels I claim:

1. In an apparatus for indirect heat exchange between a liquid medium and a vapour medium, the combination of a rotor including a nest of annular disks having spaced conical portions and also having interengaging a set of radial flnages at their outer peripheries and interengaging a set of radial flanges at their inner peripheries, a stationary casing, a drive shaft on which the rotor is mounted through said inner flanges for rotation about an axis in said casing, the casing defining a chamber surrounding the rotor, said conical disk portions forming a series of conical channels of which alternate channels are for passage of said liquid medium and the other channels are for passage of said vapour medium, said outer flanges having first passages through which said alternate conical channels communicate with said chamber, the rotor having an annular groove surrounding and opening toward said axis, said outer flanges having second passages through which said other conical channels communicate with said groove, a stationary paring device located in said groove and forming an outlet therefrom, means for sealing said groove from said chamber, said chamber having a vapour outlet and a liquid outlet, said inner flanges forming an axial passage extending generally parallel to said shaft and opening toward one end thereof to form an inlet for one of said media, said inner flanges having radial passages leading from said axial passage to said alternate conical channels, a first stationary inlet duct for said one medium, a sealed flow connection through which said first duct communicates with said axial inlet passage in the inner flanges, and a second stationary inlet duct for admitting the other medium and communicating with said other conical channels by way of said annular groove and one of said flange sets.

2. The combination according to claim 1, comprising also a suction pipe leading from said vapour outlet of the chamber for evacuating the same.

3. The combination according to claim 1, in which said inner flanges form passages through which said annular groove communicates with said other conical channels.

4. The combination according to claim 1, in which said first passages in the outer flanges include radial passages Opening directly into said chamber from said alternate conical channels.

5. The combination according to claim 1, in which said first passages in the outer flanges include an axial passage opening into said chamber through one end of the rotor.

6. The combination according to claim 1, in which the rotor has an external annular groove opening toward said axis, said first passages including an axial passage formed by said outer flanges and leading to said external groove, the combination comprising also a stationary paring device located in said external groove and forming an outlet therefrom.

7. The combination according to claim 1, in which said second passages in the outer flanges include an axial passage communicating at one end with said annular groove at one end of the rotor, the opposite end of said last axial passage being vented to atmosphere outside said chamber by way of said inner flange at the opposite end of the rotor.

8. The combination according to claim 1, in which said inner flanges form annular chambers having overflow edges leading into said alternate conical channels, said axial passage leading to said annular chambers by way of said radial passages in the inner flanges.

9. The combination according to claim 1, in which said first passages in the outer flanges include main radial passages opening directly into said chamber and also include an axial passage leading toward one end of the rotor, said first passages also including additional radial passages leading from said alternate conical channels to said last axial passage, said outer flanges having annular projections extending inwardly into each said alternate channel between the inner ends of said main and additional radial passages from the channel.

10. The combination according to claim 1, comprising also a frame supporting said casing and shaft and forming a discharge channel, said paring device being secured to the frame and leading to said discharge channel.

11. The combination according to claim 1, in which said shaft is vertical and supports said disks with their largest diameters up and their smallest diameters down.

References Cited by the Examiner UNITED STATES PATENTS 3,092,180 6/1963 Dahlgren 88 CHARLES SUKALO, Primary Examiner.

Claims

1. IN AN APPARATUS FOR INDIRECT HEAT EXCHANGE BETWEEN A LIQUID MEDIUM AND A VAPOUR MEDIUM, THE COMBINATION OF A ROTOR INCLUDING A NEST OF ANNULAR DISKS HAVING SPACED CONICAL PORTIONS AND ALSO HAVING INTERENGAGING A SET OF RADIAL FLANGES AT THEIR OUTER PERIPHERIES AND INTERENGAGING A SET OF RADIAL FLANGES AT THEIR INNER PERIPHERIES, A STATIONARY CASING, A DRIVE SHAFT ON WHICH THE ROTOR IS MOUNTED THROUGH SAID INNER FLANGES FOR ROTATION ABOUT AN AXIS IN SAID CASING, THE CASING DEFINING A CHAMBER SURROUNDING THE ROTOR, SAID CONICAL DISK PORTIONS FORMING A SERIES OF CONCIAL CHANNELS OF WHICH ALTERNATE CHANNELS ARE FOR PASSAGE OF SAID LIQUID MEDIUM AND THE OTHER CHANNELS ARE FOR PASSAGE OF SAID VAPOUR MEDIUM, SAID OUTER FLANGES HAVING FIRST PASSAGES THROUGH WHICH SAID ALTERNATE CONICAL CHANNELS COMMUNICATE WITH SAID CHAMBER, THE ROTOR HAVING AN ANNULAR GROOVE SURROUNDING AND OPENING TOWARD SAID AXIS, SAID OUTER FLANGES HAVING SECOND PASSAGES THROUGH WHICH SAID OTHER CONICAL CHANNELS COMMUNICATE WITH SAID GROOVE, A STATIONARY PARING DEVICE LOCATED IN SAID GROOVE AND FORMING AN OUTLET THEREFROM, MEANS FOR SEALING SAID GROOVE FROM SAID CHAMBER, SAID CHAMBER HAVING A VAPOUR OUTLET AND A LIQUID OUTLET, SAID INNER FLANGES FORMING AN AXIAL PASSAGE EXTENDING GENERALLY PARALLEL TO SAID SHAFT AND OPENING TOWARD ONE END THEREOF TO FORM AN INLET FOR ONE OF SAID MEDIA, SAID INNER FLANGES HAVING RADIAL PASSAGES LEADING FROM SAID AXIAL PASSAGE TO SAID ALTERNATE CONICAL CHANNELS, A FIRST STATIONARY INLET DUCT FOR SAID ONE MEDIUM, A SEALED FLOW CONNECTION THROUGH WHICH SAID FIRST DUCT COMMUNICATES WITH SAID AXIAL INLET PASSAGE IN THE INNER FLANGES, AND A SECOND STATIONARY INLET DUCT FOR ADMITTING THE OTHER MEDIUM AND COMMUNICATING WITH SAID OTHER CONICAL CHANNELS BY WAY OF SAID ANNULAR GROOVE AND ONE OF SAID FLANGE SETS.