US3498591A - Small bore roll syphon - Google Patents

Description

March 3, 1970 D. CALKINS 3,498,591

SMALL BORE ROLL SYPHON Filed May 5, 1968 "EE Q Q v LAZKETJZR Q N ATTORNEYS United States Patent Ofica:

Patented Mar. 3, 1970 ABSTRACT OF THE DISCLOSURE A rotating syphon system particularly suitable with rotary heat exchanging rolls having a relatively small axial bore in which the heat exchanging medium circulates. The syphon apparatus being mounted exteriorly of the roll at one end thereof and permitting the liquified medium to readily flow from the bore into the syphon system to prevent accumulation of the medium within the bore.

BACKGROUND OF THE INVENTION The invention pertains to the field of art of removing a heat exchanging medium, such as steam condensate, water, or the like, from a rotating heat exchanger roll.

Paper mills, fabric producing plants, and other manufacturers of web and strip products use rotary heat exchanging rolls for heating and cooling purposes. Such rolls include an outer cylindrical heat exchanging surface over which the paper, fabric or other web passes and is heated or cooled, as desired. Usually, such heat exchanging rolls have a relatively thin wall whereby the transfer of heat through the drum periphery shell from or to the medium within the drum readily occurs, Commonly, syphon apparatus is employed within the drum to remove the steam condensate, or cooling water, therefrom in order to maintain the efficiency of the roll.

Some types of heat exchanging rolls use a thick peripheral wall, to produce a large mass in order to obtain uniform and close temperature control, and for other purposes. Such drums incorporate a relatively small axial bore into which the heat exchanging medium is introduced, and are commonly known as small bore rolls.

Unless the steam condensate, in a steam heated drum, or the heated water, in a cooling drum, can be quickly removed from the drum the build-up of the condensate or warmed water within the roll acts as an insulating wall or barrier between the medium within the roll and the drum periphery, and reduces the efiiciency of the exchange of heat therebetween. The adverse conditions caused by condensate in a rapidly rotating heating drum, for instance, are especially noticeable when the drum rotates at a great enough speed to produce sufiicient centrifugal force to cause a film of condensate to uniformly extend about the entire inner shell of the drum and thereby completely insulate the drum shell from the steam within the drum, The overcoming of this type of problem in thin wall rolls is set forth in the assignees United States Patent 3,242,583.

Little development has taken place concerning the efficient removal of heat exchanging mediums from small bore rolls. Reference is made to United States Patents 1,900,166 and 2,460,059. The prior art syphon devices are usually not readily adaptable to small bore syphon rolls because of space limitations. The diameter of the bores in small bore rolls is such that conventional radially extending syphon pipes cannot be employed, and conventional syphoning systems are not adaptable to this type of structure.

SUMMARY OF THE INVENTION It is the purpose of the invention to provide a syphon system for use with small bore rotary heat exchanging rolls which is capable of efliciently removing the waste heat exchanging medium from a small bore roll in an efficient and effective manner without permitting the medium to be removed from building up and acting as an insulating barrier within the bore.

T 0 this end the invention consists of a syphon housing which is afiixed to the end of a small bore roll, The bore within the roll intersects the end of the roll to which the syphon housing is attached, and the housing includes a chamber into which the medium to be removed from the roll bore may directly flow. This flowing of the medium from the bore into the syphon housing is under gravitational forces, in a slowly rotatingroll, and is significantly augmented in a rapidly rotating roll by centrifugal force acting upon the medium being removed.

A chamber within the housing receives the medium flowing from the roll bore in an unrestricted manner, permitting the medium to freely fiow from the bore. The housing chamber includes a collecting portion for the medium, and the medium is removed from this collecting portion at a rate at least as great as the rate in which the medium is collected. Thus, no accumulation of collected medium within the syphon housing occurs which would hinder flow into the housing, The collected medium, such as condensate, is withdrawn from the syphon housing collecting chamber at a loctaion a greater radial distance from the axis of roll rotation than the radius of the roll bore to insure free and unrestricted flow from the roll bore into the chamber and collection portion.

The syphon housing is attached to the roll for rotation therewith, and suitable rotating joint structure is employed in conjunction with the housing to permit the collected medium to be withdrawn from the housing.

In that a heating medium, such as steam, or a cooling water or the like, in the case of a cooling roll, is to be introduced into the roll bore at the same time that the condensate or warmed water is removed, it is also a purpose of the invention to provide means for introducing the heat exchanging medium into the roll bore, as well as provide means for removing the same. To this end a medium supply passage is formed in the syphon housing which communicates with a conduit extending into the roll bore. Thus, attaching the syphon housing to the roll simultaneously provides means for introducing a heat exchanging medium into the roll, and means for removing the medium from the bore in an efficient and effective manner. The rotary joint through which the syphoning occurs, also provides means for introducing the heat exchanging medium into the syphon housing and conduit.

It is therefore an object of the invention to provide a highly efiicient rotating syphon system for use with small bore heat exchanging rolls which permits the heat exchanging medium to be removed from the roll bore in an expeditious manner as to maintain the heat exchanging characteristics at an efiicient level. An additional object of the invention is to provide a syphon system for a small bore rotating syphon system wherein the syphon apparatus may be readily attached to and mounted upon existing rolls without requiring extensive modification thereto.

An additional purpose of the invention is to provide a syphon system for small bore rolls which is relatively inexpensive to manufacture, and may be used with conventional rotary joints and other ancillary apparatus.

3 BRIEF DESCRIPTION OF THE DRAWINGS The aforementioned purposes and objects of the invention will be apparent from the following description and accompanying drawings wherein:

FIG. 1 is an elevational diametrical sectional view of a small bore rotary heat exchanging roll utilizing a syphon system in accord with the invention,

FIG. 2 is an elevational view of the syphon system joint and housing as taken from the right of FIG. 1,

FIG. 3 is an enlarged elevational detail sectional view taken through the syphon housing along section III-III of FIG. 1, and

FIG. 4 is an enlarged elevational detail sectional view taken through the interior of the roll through the bore and conduit along section IVIV of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The environment in which the invention is used will be best appreciated from FIG. 1 wherein the combination of components constituting a complete installation is illustrated. For purposes of description, the heat exchanging medium will be considered to be steam, and the medium removed from the roll bore will be steam condensate. Of course, the syphon system of the invention can be used in a roll used for cooling purposes, and the inventive concept is to be understood as also applicable to this type of installation.

A typical small bore rotary heat exchanging roll is generally indicated at 10. The roll is of a cylindrical configuration having a peripheral heat exchanging surface 12 over which the web of paper, fabric or other material to be heated or cooled passes. The roll includes concentric axially extending journal portions 14 which are received within bearings schematically represented at 16. In thisv manner the roll is rotatably supported, and drive means, not shown, are normally associated with the roll for retating the same at the desired speed.

The roll 10 is provided with an axially extending bore 18 which intersects the roll ends and is closed at one end by a plate 20. It will be noted that the diameter of the bore 18, as defined by the cylindrical surface of the bore, is small as compared with the outer diameter of the roll. Thus, a significant mass of roll material exists between the bore and the roll surface 12. For this reason, the roll 10 is considered a small bore roll. For instance, the diameter of the bore 18 may be in the neighborhood of three or four inches while the diameter of the roll may be inches or more.

The bore 18 intersects the right roll end journal surface 22 and the syphon stnlcture is attached to the right roll journal end as illustrated.

The syphon structure includes a housing 24 of a generally cylindrical configuration and includes an annular fiat mounting surface 26 adjacent a radial shoulder surface 28, which corresponds to the configuration of the end of the journal and is able to seat tightly thereon. If desired, a gasket, not shown, may be inserted between the roll end 22 and the housing. The housing 24 is mounted upon the end of the roll by conventional mounting apparatus such as bolts, fasteners or screws threaded into the end of the roll, not shown.

The syphon housing includes a generally cylindrical chamber 30 which intersects the mounting surface 26 as to directly communicate with the roll end 22. The chamber is of a diameter significantly greater than the diameter of the roll bore 18 and, preferably, the housing 24 is mounted upon the roll such that the chamber 30 is substantially concentric with the bore.

A radially extending passage 32 is defined in the housing 24 communicating with the chamber 30 at an inlet orifice 34, FIGS. 1 and 3. In this manner the portion of the chamber 30 adjacent the inlet 34 defines a collecting portion of the chamber as defined by that portion of the chamber radially extending from the inlet 34 to the chamher outer wall 36'. It is to be noted that the inlet 34 is radially'located with respect to the axis of rotation of the roll 10 a greater radial distance than the radial distance of the surface of the bore 18 from the roll axis of rotation.

A second passage 38 is defined in the housing 24 which communicates with an elongated conduit 40 extending through the chamber 30 beyond the plane of the mounting surface 26 and into the bore 18 of the roll. The conduit 40 may be affixed to the housing 24 by means of a plate 42 wherein communication through the passage 38 into the conduit 40 is established.

The conduit 40 is provided with axially spaced spacer plates 44, FIG. 4, which concentrically locate the conduit within the bore 18 and permit a free flow of steam, and condensate, through the bore. These plates are of a rectangular configuration having trimmed corners 46 which engage the bore surface. The left end, FIG. 1, of conduit 40 is open wherein the steam flowing through the conduit end enters the roll bore as indicated by the arrows.

The fluid conducting connection between the rotating housing 24 and the necessary steam supply and syphon conduits is accomplished through cylindrical conduits extending from the housing communicating with a rotary joint as later described. The inner or syphon conduit 48 is concentrically mounted within the housing 24 in communication with the syphon passage 32 and the concentric and larger steam supply conduit 50 is mounted in the housing and communicates with the housing passage 38.

The conduits 48 and 50 extend into a conventional rotary joint 52 which may be of the type shown in United States Patent 2,385,421. Steam is supplied to the joint 52 through conduit 54, and the conduit 56 is connected to the syphon system. Within the joint 52 the conduit 54 communicates with conduit 50 and the conduit 56 communicateswith the conduit 48.

The rotary joint 52 may be mounted upon a typical yoke 58, FIG. 2, by means of arms 60 associated with the joint wherein the yoke is bolted to the fixed support structure for the roll, for instance, the members in which the bearings 16 are mounted, not shown. In this manner the joint 52 is restrained against rotation while the conduit's 48 and 50 rotate.

In operation, the steam is supplied to the roll 10 through the supply conduit 54 and flows through the rotary joint 52 into the conduit 50, passage 38 and conduit 40 into the bore 18. The steam within the bore 18 heats the roll and condenses and the resultant water condensate tends to form a film upon the bore surface, in a rapidly rotating roll. If the roll 10 is rotating slowly, the condensate will accumulate at the lower regions of the bore.

Accumulation of the condensate within the roll bore is prevented, in accord with the invention, in that the condensate will flow along the bore past the spacer plates 44 toward the right end of the roll, FIG. 1. This movement of the condensate occurs regardless of the speed at which the roll rotates in that the axis of the roll is horizontal. In most modern applications the roll 10 rotates at a speed which will cause the condensate to produce a film throughout the periphery of the bore, and upon the condensate reaching the thickness of a few thousandths of an inch the condensate will begin to flow toward the open bore end and housing 24. Upon the condensate reaching the open roll end it is thrown, or falls, into the chamber 30. In that the syphon inlet 34 is located in the chamber 30 at a radial location, with respect to the axis of rotation, greater than that of the bore surface, the level, or radial thickness of the condensate within the chamber 30 as indicated at 62, is such that the flow of condensate into the chamber is free and unrestricted. Thus, a minimum thickness of condensate film within the roll bore 18 is maintained.

As the amount of condensate within the chamber 30 increases to the point where the level reaches the inlet 34 the condensate will flow into the inlet and passage 32, through the rotary joint 52 and to the syphon system conduit 56.

The unique construction and relationship of the components within the syphon housing 24 insures the aforedescribed operation of the syphon system and by removing the condensate quickly from the bore 18 the heat exchanging capabilities of the roll are maintained at a maximum value.

It will be noted that as the housing 24 is exteriorly mounted on the roll 10 that all of the described components, except the conduit 40, are located outside of the roll, and maintenance and replacement of the syphon system components is simplified, as well as simplifying installation techniques. In that the chamber 30 completely surrounds the bore 18 the condensate may flow into the chamber throughout the entire circular intersection of the bore and the roll end 22, which prevents the occurrence of a dam or other obstacle to free condensate flow from the bore.

It will be appreciated, of course, that if the roll 10 is to be used for cooling purposes, the cooling water is supplied to the roll through the conduit 54, and removed through the syphon conduit 56. When the roll is used for cooling, the ready removal of the water from the bore 18 is not quite as critical as the removal of steam condensate, and the advantageous construction of the syphon system of the invention is best utilized in a steam heating application.

It is appreciated that various modifications to the described embodiment may be apparent to those skilled in the art without departing from the spirit and scope thereof.

I claim:

1. A syphon system particularly suitable with small bore heat exchanging rotary rolls comprising, in combination, a heat exchanger roll having ends and an axis of rotation, a peripheral heat exchanging surface and a coaxial bore having an inner surface, said bore intersecting one of said roll ends, bearing means rotatably supporting said roll, means for introducing a heat exchanging medium into said bore, a housing aifixed to said intersected end of said roll, an annular chamber defined in said housing concentrically related to said roll axis and having a diameter greater than that of said bore and disposed toward said bore for communication therewith, a first passage defined in said housing having a first portion remote from said chamber and coaxial with said roll axis and of a diameter less than the minimum diameter of said chamber and a second portion transversely disposed to said first portion, an inlet defined in said passage second portion communicating with said chamber, said inlet being a greater radial distance from said roll axis than said bore inner surface, and rotary joint syphon means communicating with said passage first portion receiving liquid removed from said bore and received within said chamber.

2. In a syphon system as in claim 1 wherein said means for introducing a heat exchanging medium into said bore includes a heat exchanging medium inlet passage defined in said housing concentric with said roll axis, a heat exchanging medium conduit communicating with said inlet passage, said conduit coaxially extending into said roll bore, and heat exchanging medium outlet means defined in said conduit remote from said housing for introducing the medium into said bore.

3. In a syphon system as in claim 2 wherein said rotary joint means includes a first conduit coaxial with and communicating with said first passage first portion, and a second conduit coaxial with and communicating with said inlet passage and conduit.

4. A syphon system adapted to be mounted upon the end of a heat exchanging rotary roll intersected by an axial bore defined in the roll comprising, in combination, a housing having an axis of rotation, an annular mounting surface defined on said housing transversely disposed to said axis and disposed about said axis adapted for abutting the end of the roll, a chamber defined in said housing intersecting said mounting surface adapted to directly communicate with the end of the roll, said chamber being concentric to said axis and of a diameter greater than the roll bore, a liquid removing passage defined in said housing having an inlet communicating with said chamber at a radial location with respect to said axis greater than the radius of the roll bore, and roll mounting means associated with said housing for mounting said housing upon the roll.

5. In a syphon system as in claim 4 wherein a heat exchanging medium inlet passage is defined in said housing, a conduit mounted in said housing in communicaton wth said inlet passage, said conduit extending through said chamber and beyond said housing mounting surface.

References Cited

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