US2902774A - Tempered turbulence roll-type drier - Google Patents

Description

Sept. 8, 1959 R. c. SWANEY TEMPERED TURBULENCE ROLL-TYPE DRIER 3 Sheets-Sheet 1 Filed Dec. 2, 1955 INVENTOR 054 115 @aoyw cswamg/ ATTOR EY 3 Sheets-Sheet 2 INVENTOR imam/K @aoyaw cs/wa vwz/g/ Sept. 8, 1959 R. c. SWANEY TEMPERED TURBULENCE ROLL-TYPE DRIER Filed Dec. 2, 1955 Sept 8, 1959 R. c. SWANEY TEMPERED TURBULENCE ROLL-TYPE DRIER 3 Sheets-Sheet 3 Filed Dec. 2, 1955 I I INVENTOR (30/6/2416 g g United States Patent TEMPERED TUREULENCE ROLL-TYPE DRIER Robert Casper Swaney, Carlisle, Pa., assignor to The Hot Oil Heater Company, Inc., Carlisle, Pa., 3 corporation of Massachusetts Application December 2, 1955, Serial No. 550,723

7 Claims. (Cl. 34-424) My invention relates broadly to an apparatus for securing uniformity in temperature on cylindrical roll surfaces and more particularly to a method and apparatus for obtaining uniform temperature conditions on roll driers.

Among the common types of heat exchangers are conventional roll driers (dry cans), Yankee driers and flaking rolls which are hollow cylindrical vessels with which paper or other materials are brought in contact therewith to perform the work or function of drying, heating or cooling of the said paper or other materials. These units are usually heated from the inside using steam or some other vapor under pressure; or cooled in similar manner usually under high pressure or vacuum. Temperature in vapor systems is a function of pressure but since the temperature increase is disproportionate to the pressure increase practicable pressure limits are soon reached; presently about 150 p.s.i.g. for saturated steam which has a relatively low temperature. In such vapor systems the cooling effect is accomplished by evaporating a liquid to a vapor; and heating is accomplished by condensing a vapor to a liquid. It has long been held that an evaporating liquid or condensing vapor because of the latent heat between the two phases, provided the best means of heat transfer because the heat transfer medium remains at a constant temperature. In the simplest of apparatus this is infallible, but in instances where high production and accurate control of temperature and heat transfer are demanded in the more complex processes, such as drying paper, chemicals and textiles thattenet has many disadvantages.

My invention provides an improvement thereupon in which heat transfer media are circulated around inside the rolls in a controlled manner to apply heat thereto or to cool by removing heat therefrom. The heat transfer media are usually liquid although they may be gas or superheated vapor and the heat transfer is that of sensible heat rather than latent heat of evaporation or condensation; however, with modifications my invention can be used with evaporating liquid or condensing vapor.

Since roll driers and Yankee driers are usually carried and revolve on journals and bearings at their axes, the practicable points of inlet and outlet are via' hollow journals or shafts fitted with rotary joints or-seals. To effect the highest efliciency of such apparatus it must be completely filled with whatever heat transfer medium is being used. In the case of steam or other vapors this creates a problem because of air or insoluble gases that can become trapped within the roll. In the case of a condensing vapor the condensate must be removed as rapidly as it is formed which often requires considerable complicated apparatus to perform the scavenging and condensate return operation. With the general availability of suitable liquid heat transfer media that do not vaporize and hence do not change phase during heating and cooling even at atmospheric pressure and at temperatures as high as 650 F. which is equal in temperature to more than 2000 p.s.i.g. saturated steam pressure, it is much simpler, cheaper and more efiicient to heat or cool such apparatus (driers) with liquid heat transfer media, because said heating or cooling can be accomplished with very little pressure on the system, often less than 15 p.s.i.g. on the user (drier), because the only pressure that is required is that necessary to circulate the heat transfer medium through the system. Maintenance is much less because many such heat transfer media are non-corrosive, whereas many vapors are. Furthermore, all heat is sensible heat (no latent heat of vaporization or condensation is involved) and hence direct temperature sensing instruments and controls simplify and greatly increase the accuracy of temperature control and heat transfer.

My invention will be more fully understood from the following specification by reference to the accompanying drawings, in which:

Fig. 1 is a longitudinal vertical sectional view through one form of roll embodying my invention and showing certain of the parts in elevation and illustrating one method of conducting and returning heat transfer medium through one end of the roll;

Fig. 2 is a transverse vertical sectional view taken on line 22 of Fig. 1; r

Fig. 3 is a fragmentary end elevational view of the em bodiment of my invention shown in Fig. 1, partially broken away and shown in section;

Fig. 4 is a longitudinal sectional view on a reduced scale of a shorter face drier roll with the internal distributor tube cantilever supported from the rotary joint with the end of the distributor tube stopped or plugged, the distributor tube being partially broken away and shown in section and certain of the parts being shown in elevation;

Fig. 5 is a fragmentary view of the distributor tube shown in the form of my invention illustrated in Fig. 4 on an enlarged scale and showing particularly the plug in elevation in the end of the tube;

Fig. 6 is a longitudinal sectional view through a modi: fied form of my invention illustrating an arrangement of heat transfer medium supply at one end of the roll and the return or exit for the heat transfer medium at the opposite end of the roll, certain of the parts being illustrated in elevation and the view being fore-shortened for the purpose of illustrating the parts of the structure on a larger scale;

Fig. 7 is a fragmentary vertical sectional view on a larger scale showing the return or exit port connection for one end of the roll;

Fig. 8 is a fragmentary view on an enlarged scale showing the return or exit end of the distributor tube;

Fig. 9 is a vertical sectional view on line 99 of Fig. 8;

Fig. 10 is a vertical sectional view on line 10-10 of Fig. 8; n

Fig. 11 is a vertical sectional view longitudinally through another modified form of my invention embodied 1 in a controlled temperature gradient drier with a reverse flow valve in a twin-port water-cooled rotary joint, parts of the structure being shown in elevation and the view being fore-shortened at two positions to enable the parts to be illustrated on a larger scale;

Fig. 12 is an end elevational view of the form of drier' roll illustrated in Fig. 11; and

Fig. 13 is a vertical transverse sectional view taken on line 13l3 of Fig. 11.

In the apparatus of my invention I provide a hollowof the hollow cylindrical roll from jets to provide a tem-' poring turbulence within the roll structure. The h'eat' transfer medium may be introduced through the disi tributor tube from one end of the roll and discharged from the interior of the roll at the same end or through the opposite end of the roll. I provide suitable journals about whic h the roll rotates. On long rolls it is necesto support the distributor tube on both ends to avoid a whipping action with rotation. On shorter rolls the distributor tube may be supported as a cantilever from the rotary joint with the remote terminating end stopped or plugged. In the form of my invention where the heat transfer medium is introduced at one end and discharged at the opposite end the distributor tube may be supported from the rotary joints, or from the internal bores of the journals.

-The attaining of uniform distribution of temperature throughout the surface of the roll is accomplished by the selective distribution of the temperatures along the distributor tube within the hollow cylinder through which the heat transfer medium is introduced. The apertures in the distributor tube provide the metering means to temper, and the jetting means, to create, turbulence in the heat transfer medium throughout the roll drier. More heat transfer medium is introduced in the opposite area of the cylindrical roll and a lesser amount in the adjacent area in a graduated manner, so that the maximum heat transfer medium which enters at the opposite end in performing work, which is the transfer of heat, returns for exiting, and the apertures or orifices, although less in number, create a jetting action by means of which turbulence is created and heat transfer medium is added which has not yet performed work, therefore a complete turbulence and tempering of the heat transfer medium occurs in proportion to the amount of work performed between entering and exiting.

Where the heat transfer medium is introduced at one journal and exits at the other journal, the distributor tube is provided with a stop or plug at the end near the exit. More of the heat transfer medium is introduced into the area adjacent the entrance journal and the lesser amount in the area adjacent the exiting journal by means of apertures or orifices so proportionally spaced and displaced betwen the entrance and the plug or stop as to accomplish the tempering turbulent action identical to that before described where entering and exiting is through the same journal. Beyond the stop or plug in the distributor tube adjacent the journal through which exiting occurs, there are provided larger apertures or orifices to readily receive the spent heat transfer medium for exiting through the journal and out through the rotary joint.

One of the further advantages of the roll construction of my invention resides in the fact that it'may be used without structural change for any duty Within the range of minus 140 F. to plus 650 F. by merely changing the heat transfer medium. For example, this wide range can be obtained from only three heat transfer media and the. apparatus operating at a pressure of less than 15 p. s.i.g. Methylenechloride can be used for temperatures from minus 140 F. to plus 100 F. at atmospheric pressure. A light turbine quality oil can be used for temperatures to 300 F.; and a heavier turbine quality oil can be used to 650 F., both at atmospheric pressure. Thus, the only pressure on the apparatus is that required to create turbulence and flow the heat transfer medium immediately through the roll.

Four forms of my invention are described hereinafter but there is a generic principle involved in all of the applications, that is, the creation of turbulence in and tempering of the heat transfer medium within the drier by jetting streams of heat transfer medium into the interior of the roll. This principle is embodied in the drier in which the distributor tube is supported at opposite ends or from a single end with single end heat transfer medium supply and exit; or where the distributor tube is divided into sections with the heat transfer me dium supply at one end and the exit at the opposite end; or where the heat transfer medium flow is distributed to provide for higher temperature center heat and lower temperature end heats, or lower temperature center heat and higher temperature end heats.

Referring to the drawings in more detail reference, character 1 designates the hollow cylindrical roll which is axially journalled at opposite ends by journalling means extending from disclike heads 2 and 3 which supportthe hollow cylindrical roll and carry outwardly projecting journalling means shown at 4 and 5. In the form of my invention illustrated in Figs. 1-5 the heat transfer medium inlet and discharge connections are located at the same end of the roll so that in this form of my invention journalling means 4 is connected with a rotary joint indicated generally at 6, whereas the journalling means 5 is supported in a conventional bearing. The journalling means 4 and 5 are solidly supported with respect to the heads 2 and 3 through sets of radially disposed internal ribs 7 and 8 respectively. The journalling means 4 comprises a cylindrical sleeve which is externally supported in a conventional bearing and which is provided with an internally arranged cylindrical sleeve 9 of insulation material annula'rly spaced around a distributor tube 10 which extends from the rotary joint 6 through the journalling means 4 longitudinally of the full length of the roll 1 and is secured at the end 10a thereof in the journalling means 5. The rotary joint 6 includes a water-cooled jacket represented at 11 having water-cooling ported connections 12 extending therefrom. Provision is made for the sealing of the junction between the journalling means 4 and the rotary joint 6 through appropriate sealing devices indicated generally at 13. The rotary joint 6 has both a central passage for the heat transfer medium and an annular passage for the heat transfer medium around the central passage. The inlet for the heat transfer medium is represented at 14 leading to the central passage 15 of the rotary joint 6 which leads to the heat transfer medium distributor tube 10. The annular passage for the heat transfer medium which extends around the central passage 15 is indicated at 16 which connects to the internal annular passage 17 conveying the heat transfer medium from the interior of roll 1 to the heat transfer medium outlet pipe indicated at 18.

The distributor tube 10 revolves with the drier and rotary joint and is provided with tempering-turbulence apertures throughout its internal length. The apertures are represented in the drawing at 19 and provide for the establishment of tempering-turbulence jets throughout the length of the roll 1 which I have indicated by the arrows 20. These jets of heat transfer medium circulate interiorly of the roll for insuring the transfer of heat uniformly throughout the surface of the roll 1. After the jets of heat transfer medium release heat to the surface of roll 1, or in the case of cooling absorb heat from the surface of roll 1, the spent heat transfer medium passes through the internal annular passage 17 and through the rotary joint 6 via annular passage 16 Where it discharges through heat transfer medium outlet 18.

In certain applications of my invention shorter face drier rolls must be employed and in such structures I provide a distributor tube such as 21 which is supported as a cantilever from rotary joint 6 with the free end thereof terminating short of the journalling means 5 and closed by a plug 22 as shown more clearly in Fig. 5. The distributor tube 10 is apertured at 23 for the distribution of jets of heat transfer medium throughout the interior of the roll 1 in Fig. 4. Similar parts of the shorter face drier roll shown in Fig. 4 have been indicated by reference characters similar to those employed in Fig. 1 with the addition of prime marks, that is, heads 2' and 3 are provided supporting the journalling means 4 and 5' and connected with ribs 7' and 8'. The free end of distributor tube 21 is steadied and supported by support means 24 in some applications in which whipping of the distributor tube 21 might result from excessive revolving speeds or length or both, support means 24 being interiorly within the roll 1.

In installations where the heat transfer medium is supplied through one end of the drier and the spent heat transfer medium is returned from the opposite end of the drier, I provide the arrangement illustrated in Figs. 6-10 wherein the roll has been indicated at 1" supported by heads 2" and 3 at opposite ends. The heads are provided with internal radially extending ribs 7" and 8" as shown. These ribs serve to support the hollow journals 25 and 26 at opposite ends of the drier. The journal 25 is provided with an interiorly arranged heat transfer medium feeding passage 27 which extends from rotary joint 28 and is aligned with the end of the heat transfer medium distributor tube 29 which extends the entire length of the roll 1" and into the journal 26. The heat transfer medium feeding passage 27 is lined with insulation 30. The rotary joint 28 connects to the journal 25 through appropriate sealing means 31. The rotary joint 28 is water-cooled as heretobefore described and is supplied by a single pipe connection which leads into the rotary joint 28 at 32 and constitutes the heat transfer medium supply to the drier. The discharge of the heat transfer medium leads through the journal 26, through rotary joint 36 and exit or return pipe 37. Sealing means 35 is interposed between the rotary joint 36 and the projecting end of the journal 26. Rotary joint 36 is similar to rotary joint 28 and is water-cooled through pipe system 12 in a manner similar to the water-cooling heretobefore explained. The exit or return pipe for the heat transfer medium is indicated at 37. The heat transfer medium distributor tube 29 is provided with a partition or a stop or plug represented at 38 located adjacent the discharge end thereof. The distance between the heat transfer medium intake end of the heat transfer medium distributor tube 29 and partition 38 is provided with apertures 39 which are proportionally displaced at varying distances to admit jets of heat transfer medium at closely related positions adjacent the intake end of the roll but at more widely spaced positions along the tube approaching the partition 38. Because of the substantially logarithmic spacing of the apertures in distributor tube 29 as in the distributor tube or 21 in the form of my invention shown in Figs. 1-5 tempering-turbulence is secured within the roll 1" of Figs. 6-10 which is equivalent to the tempering-turbulence secured in the roll 1 of Figs. 1-5. The heat transfer medium distributor tube 29 is provided with heat transfer medium intake apertures 40 between the partition 38 and the journal 26. The heat transfer medium after churning a condition of turbulence within the roll 1 as represented at 41 is discharged in the direction of arrows 42 through the apertures 40, heat transfer medium passage 33, rotary joint 36 and exit pipe 37. This arrangement insures a constant temperature per lineal inch of the surface of the roll 1".

In Figs. 11-13 I have illustrated the principles of my invention applied to a displacement drum type of roll. In this arrangement temperature gradients may be controlled from high center to low sides. The roll is indicated at 1" closed by heads at opposite ends represented at 2" and 3". The head 2" carries journalling means 43 for the introduction and discharge of heat transfer medium from the same end of the roll 1". The head 3' carries journaling means 44 for the opposite end of the roll 1". Strengthening means 7" and 8" associated with heads 2" and 3 respectively serve to firmly support the journal means 43 and 44 respectively. The journalling means 43 is arranged in a manner similar to the journalling means 4 of Figs. 1-5. I have represented the rotary joint at 45 which is jacketed and watercooled through pipe system 12. The heat transfer medium supply is carried through pipe 46 to the central heat transfer medium feeding passage 47 which extends from the rotary joint 45 through the annula r passage 48 stantially midway of the insert drum or vessel designated at 51. The insert drum or vessel 51 extends substantially the entire length of the interior of the drier 1" and is provided at opposite ends with a reentrant type of head shown at 52 and 53. The reentrant type heads 52 and 53 connect at their peripheral edges to the interior of the insert drum or vessel 51 and carry adjacent their centers and spaced around the central heat transfer medium feed passage 47 tubes 54 and 55 constituting passages for heat transfer medium from one of the reentrant heads to the other reentrant head. The insert drum or vessel 51 is spaced from the interior cylindrical wall of roll 1" by a partition 56 located midway of the roll. The insert drum or vessel 51 also contains a partition 5'7 similar to partition 50. The partitions 50 and 57 are spaced apart and extend parallel in planes on either side of the plane of partition 56 and have sufiicient distance to accommodate a pair of spaced peripheral rows of apertures shown at 58 and 59 which provide discharge paths for the heat transfer medium emanating from the discharge end of the central heat transfer medium feed passage 47 shown at 47a. rows of apertures 58 and 59 open into the cylindrical jacket 60 between the surface of the outside wall of the insert drum or vessel 51 and the interior cylindrical surface of the roll 1". Thus the distribution of heat transfer medium takes place from the center of the roll outwardly toward each end thereof along the path designated by the arrows 61 returning through annular rows of perforations 62 and 63 adjacent the opposite ends of the insert drum or vessel 51 and beyond the position of the reentrant heads 52 and 53. The heat transfer medium return path for the heat transfer medium conveyed through annular row of perforations 63 follows the course indicated by arrows 64 through the tubes 54 and 55 leading to the annular discharge path 48 through the journalling means 43 and through the return pipe 65 indicated A fio w reversing valve 68 is provided in the supply and return pipe system leading to the rotary joint 45 to enable the direction of the flow of heat transfer medium to be reversed at will. By reversing the direction of flow the heat transfer medium may be introduced at the ends of the roll and the spent heat tranefer medium discharged at the center of the roll. Thus by controlling the direction of flow the temperature gradients may be controlled from high sides to low center instead of from high center to low sides as shown in Figs. 11-13. The supply and return pipes 46 and 65 are not reversed but the heat transfer medium flow through rotary joint and roll is reversed and the conditions will be exactly as depicted in the drawings except that the direction of the arrows 61, 64- and 66 and their associated arrows will be reversed.

Various means not shown are provided for rotatably driving the rolls 1, 1" or 1" in bearings provided for the journals 4-5; 25-26; or 4344. The roll is rotated while the tempered-turbulence is produced within the roll.

A sufficient pressure head is established at the intake end of the fluid distributing tube to insure the jetting of the heat transfer medium into the interior of the roll in all of the various forms of my invention.

I have found the system of my invention highly practical in maintaining constant temperatures throughout the surface or for purposes of controlling the distribution of temperatures along the roll surface and while I have The peripheral described my invention in certain of its preferred embodinients I realize that modifications may be made and I desire that it be understood that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

i 1. A roll type drier comprising a hollow cylindrical roll, means for journalling said roll at opposite ends thereof, one of said means comprising an oil feeding and discharging journal, an oil distributor tube extending axially from said journal to a position substantially central of said roll, means for directing oil at high pressure and temperature from said oil distributor tube to the interior surface of said'hollow cylindrical roll, means for directing the flow of hot oil from the central position of said roll toward opposite ends thereof for tempering the surface of said roll, a re-entrant head disposed in each end of said roll for collecting the spent oil at opposite ends of said roll, and a pair of open tubes extending parallel to each other on opposite sides of said oil distributor tube and terminating in said reentrant heads for directing the spent oil through the discharge portion of said oil feeding and discharging journal from each of said re-entrant heads.

2. A roll type drier comprising a cylindrical roll, journalling means at each end of said roll, at least one of said journalling means including an oil inlet and discharge connection, means for controlling the flow of oil through said last mentioned journalling means, an oil distributor tube connected with said oil inlet connection and terminating midway of the length of said roll, means for distributingoil from said position midway of the length of said roll toward opposite ends of the roll for tempering the internal surface of the roll, a re-entrant head in each end of said roll for collecting the spent oil adjacent opposite ends of the roll, and a pair of open conduits arranged symmetrically on opposite sides of said oil distributor tube and terminating in said reentrant heads for directing the spent oil from both of said heads to the discharge connection of said journalling means.

3. A roll type drier comprising a cylindrical roll, journalling means at each end of said roll, at least one of said journalling means including an oil inlet and discharge connection, means for controlling the direction of flow of oil through said last mentioned journalling means, an oil feeding tube connected with said oil inlet connection and terminating midway of the length of said roll, a drum face thereof'to provide an annular jacket for the circulation of oil, a pair of partition plates spaced from each other and dividing said drum into two parts, said plates being disposed in positions in which said oil feeding tube terminates therebetween and defining a path for oil extending from the terminus of said oil feeding tube to the saidjacket, said drum being perforated throughout the space defined by said pair of partition plates for establishing paths for the passage of oil through said jacket continuous with the aforesaid path for oil and a re-entrant head in each end of said roll and connected peripherally with said jacket for receiving the flow of oil therefrom and means defining an additional path for oil extending between said re-entrant heads and the ends of said drum and into saidoil discharge connection.

4. A roll type drier as set forth in claim 3 in which a portion ofthe means defining said last mentioned additional path for oil consists of an open conduit extending longitudinallybetween the ends of said drum.

5. A roll type drier as set forth in claim 3 in which the means defining said last mentioned additional path for oil is formed by a pair of tubes extending longitudinally through opposite ends of said drum on opposite sides of said oil distributor tube.

6. A roll type drier as set forth in claim 3 in which the discharge end of said oil feeding tube is supported by one of said plates.

7. A roll type drier as set forth in claim 3 in which the discharge end of said oil feeding tube is supported by one of said plates, and wherein .an annular partition member is located midway of the perforations in said drum and extends to the internal surface of said roll for directing the flow of oil in opposite directions within said jacket to each of said re-entrant heads.

References Cited in the file of this patent UNITED STATES PATENTS 1,669,774 OMalley May 15, 1928 1,693,934 Millspaugh Dec. 4, 1928 2,281,406 Bergman m Apr. 28, 1942 2,516,199 Fry July 25, 1950 FOREIGN PATENTS 5,866 Germany Sept. 27, 1878 161,446 Germany June 28, 1905 558,990 Great Britain Jan. 31, 1944

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