US1764713A - Condensate-removal device for high-speed paper driers - Google Patents

Description

June 1930. v A. E. VBVROUGHTON I,764,713

CONDENSATE REMOVAL DEVICE FOR HIGH SPEED ?AFER DRIERS Filed April 23 1928 IIIIIIII'; l//ll Wu& .47

Patented June 17, 1930 miree ARTI-IUR E. 'BBOUGHTOL OF MHJNEAPOLIS, MINNESOTA CONDENSATE-REMOVAL DEVICE FOB. HIGH-53315313' PAPEE DRIERS Application filed April 23,

Heretofore Wherepaper driers have been operated at peripheral speeds of more than 800 feet'per minute the removal of the con: densate has been intermittent and this has made it necessary to frequently change the pressure at Whichthe stean is supplied to the driers. Even Where rapid and frequent changes in the pressure are made it has not been possible in the old syste 'to secure uniform dryingof the sheet. ,This lack of uniformity in the drying has led to the practice of removing more than the requisite amount' oi? Inoisture' from some parte ol* the sheet With consequent losses to the manufacturer. In the old systems the intake opening in the Withdrawal pipo has been loeated'at a point closely acent to the lower periphery of the drier but this does not efie ct a continuous withdrawal because When the higher speeds are. attaineda relatively large amount of condensate is carred around with the drier by centritugal force and is retained in a film or' layer extending upon the entire inner periphery of the drer. Periodieally, When the condensate has collected in such a large amount that it can no longer be so carried around, it suddenly 'falls and is drawn out of the drier rapidly for the short period oi: time required to reduee the quantity remaining in the drier to a point Where it is again spread uponthe entire periphery. This periodical withdrawal of large amounts of the condensate is What is known as slugging and causesthe detrimental variations in 'the rate of drying. e

It is my object to eliminate such slugging and the necessity for over drying and rapid changes in the steam pressure by' providing 40 efiicient means tor substantially continuously removing condensate from high speed driers. Other object-s Will appear and be more fully pointed out in' the following specification and claims.

I have found by experiment that With a gven cylindrical drier containing a fixed small amount of Water that this Water will remain in a relatively stationary body in the bottom When the drier is rotated at periphoral speeds below about 800 feet per minute.

tablished.-

1928." Serial No. e''zgee.

As the speed of this 'drier is increased the Water tends more and more to 'follow around the `periphery and When another somewhet hi er speed is reached it iscarried part tmi around and then falls transversely of 5'5 the ais of the drier. At a 'still higher 'speed With the same drier containing the same amount of water the entire body of Water Will adhere to the periphery and need over'the entire peripheral surface of Gb the driver ina relatively thin layer or film.

Conversely when a drier is operated at any shbstantially 'uniform speed above about 800 feet per minute there is a corresponding small quantity of Water which Will spread upon the periphery and rot'ate With the drier, a somewhat larger amount which Will be carried partially around the perijher'y and a still larger amount which Will` e retained in a s ationary body in the bottom. Of course it is undesirable to form an insuiating film o'i ater upon the in'ner periphery oi the drier. ".`herefore it is ad vantagcous to retain suiicient water in 'the drier so that it Will not be carried completely around by the centrfugal force. On the other hand, it s best to remove as much as possbie down to the lii'nt thus es-`-` By thepresent invention `I maintain a G balance between the two extremes by providing` one element adapted to prevent the removal of an excessive amount and another element awpted to remove a maximum w jiich it possible to remove above the point Where the Water Will spread upon the periphery of the drier. I provide a receptacle located in such position that it Will collect and remove a substantial part of the (I Water which falls transverse the axis of the Hier. An intake opening in a Witbdrawal pipe is located at a 'point sufiiciently far above the lower' periphery of the drer to retain a predetermined minimum of Water (depending on the speed of the particular drier) which is large enough so that it 'Will not be earried in a fihn covering the .inner periphery. "lfhus in the normal operation of the driers at a predetermined high speed I' retan the Water therein at the critical 'together with suitable means is a section of the U-s point where the excess continuously falls transverse the aXis and is caught in a receptacle from which it is removed.

In the accompanying drawings Figure 1 is a longitudinal, vertical section through a drier of common type with my improved condensate removal device attached thereto, for admitting steam and for rotating the drier; Fig. 2 is an enlarged transverse section through the drier and present invention taken on the line 2-2 of Fig. 1; Fig. 3 is an enlarged 'ragmentary, longitudinal section through anend of the device and drier-and Fig. 1- haped part of the withdrawal pipe and adjacent connections.

In the drawings 'the numeral 5 indicates a cylindrical drier of the common type mounted with its aXis substantially horizontal and supported 'for rotation in suitable bearings 6 and 7. Fixed on one end of the drier is an aXial shaft 8 which projects through the hearing 7 and is provided with a driving gear 9 of common type. The shaft 8 is hollow, being provided with a passageway communicating with the interier of the drier 5 through an opening 10. A condensate removal pipe 11 extends axially through the sha't 8 and opening 10. At its oute'r end the pipe 11 is Secured to a stationary fitting 12. From this fitting it passes through a hollow head 13 communicating with a steam supply pipe 14.

Projecting axially into the drier 5, the pipe`1l has a central hearing 15 in a spider 16, said spider being bolt-ed to the, end of the drier so as to rotate around the stationary pipe 11. Beyond the'bearing 15 the pipe 11 communicates with a T coupling 17 which in turn connects with one end of a U-shaped pipe 18. 'The lower extremity of this U pipe is located near the inner periphcryof the drier and one or" its branches communicates through a 'T' coupling 19 with an axially positioned pipe 20. Openings 21 in the upper periphery of the pipe 20 admit condensate thereto from a receptacle 22 which extends longitudinally within the drier and projects later lly from the central part thereof. This receptacle 22, as best shown in Fig. 2 is supported upon the pipe .20 and arranged to drain into said pipe. As shown in Fig. 3 the pipe 20 is closed at its end remote froni the U pipe 18 and is supported by a spider 23 similar to the spider 16, a suitable journal hearing 2 1 being provided between the pipe and spider to permit rotation of the spider with the drier, the pipe 20 being stationary.

It will be noted, as shown in F ig. e, that a threaded plug 24: is arranged to close adjacent branches of the couplings 17 and 19 while an intake opening 26 is located in the upper periphery of the U pipe 18 near its lower extremity. Thus the pipe 20 comniunicates through the U pipe 18 with the 'pipe 11 and is arranged to empty by gravity into the U pipe. suitable unions 27 are provided to facilitate making the connection of the U pipe 18 to the couplings 17 and 19.

Any suitable or well known means may be provided for forcing or withdrawing the condensate out through the pipe 11. As illustrated, such means are of the type shown in my Patent No. 1,575,6l5 dated March 9th, 1926, for heating systems for paper driers. Thus a pipe 28 is arranged to communicate at one end with the condensate header 29 and at its other end with the pipe 11. A check Valve 30 is located in the pipe 28 to permit flow of condensate from the drier into the ,header 29 while preventing flow of steam in the reverse direction. The steam supply pipe 1 1 is connected to the steam header 31 of the paper drier 111 a suitable manner.

Operatime moved in the direction of rotation from the lowest point of the inner periphery. The arrow in F ig. 2 indicates the direction of r0- tation. The height of the U pipe 18 is such that with a given speed the opening. 26 will he located far enough from the inner periphery' so that it cannot reduce the quantity of* condensate torsuch a degree that it carries around with the drier.

hen starting a high speed paper drier it operated. at a speed considerably below the normal and during this period of low speed operation the U pipe 18 operates to withdraw the condensate into the opening 20 as fastas it is formed. Thus as soon as the opening 26 is covered by condensate, steam in the pipes l and 28 and in one arm of the pipe 18 condenses and creates a partial vacuum which draws the condensate into the pipe 28 whence it fiows by gravity past the check valve 30 into the header 29.

When the speed of the drier is increased to its normal Operating speed above 800 feet per minute, the condensate within the drier tends to`^iollow around the periphery of the drier until it reaches a point where some of it falls transverse the axis of the drier as shown at 33 in Fig. 2. A substantal part of the water thus caused to fall is caught in the receptacle 22 whence it flows into the pipes 20 and 18 and is drawn out as above described. In this manner a sufiicient quantity is continuously removed to prevent an objectionably large amount from accumulating. Only as long as the water is falling from the upper periphery of the drier is it withdrawn by the In this manner, and with proper adjust ment of the location of the opening 26, the condensate is continuously withdrawn both at the lower starting speeds and at the normal Operating speed oi: the drier. I have found that with a high speed drier, 4 feet 8 inches in inside diameter andnormally operating at a peripheral speed of about 900 feet per minute the opening 26 should be about 2 4 inches from the nearest point on the inner periphery of the drier. It will be readily understood that the spacing of the opening 26 from the periphery of the drier is greater for higher Operating speeds and smaller for lower speeds to insure retention of the critical minimum quantity of condensatewithin the drier.

Where a peripheral speed of 900 to 1,000 feet per minute is required, the spacing of the opening 26 from the lowest point on the inner periphery of the-drier is made about two and one-half inches so as to retain, when the drier is stationary, water at a depth `of about two and one-half inches in the bottom of the drier. For a peripheral speed of 1,200 feet per minute about three inches of` water should be retained in the bottom when the drier is stationary, while an amount represented by a depth of 'from three to four inches is required for a peripheral speed of 1,400 feet per minute on the same drier of four feet eight inches internal diameter. These are the high speeds which are now required. v It will be evident that where the peripheral speed of the drier is known in advance, the pipe 18 'may be designed to retain the opening 26 at the desired distance from the bottom, but where it is desired to change the speed from time to time adjustment of the height of the opening 20 ma be made by merely changing the angle of the pipe '18 relative to the vertical plane through the aXis of the drier.

Having described my invention what I claim is new and desire to protect by Letters Patent is:

y 1. In a condensate removal device for a high speed cylindrical drier, a condensate removal pipe having an intahe opening spaced from the lower periphery of said drier to retain a predetermined minimum of condensate within the drier 'which is in excess of that which will adhere to the entire periphery of said drier when the same is operated at a predetermined high speed and a receptacle arranged to continuously remove condensatedn excess of a predetermined amount when said drier is operated at the same high speed. i

2. In a condensate rcmoval devicefor a high speed cylindrical drier, a condensate removal pipe having an intake opening spaced from the lower periphery of said to continuously collect quantities of con-` densate in eXcess of a predetermned amount, and connections for removing condensate from 'said pipe and receptacle.

3. In a condensate removal device or a high speed cylindrical drier, a oondensate removal pipe having an intake opening spaced from the lower periphery of said drier to maintain a predetermined minimum of condensate within .the drier, said minimum being in exeess of the quantity which will adhere to the entire periphery of said drier when the same. is operated at a predetermined high speed and a receptacle arranged 'to collect quantities of condensate falling from the` upper periphery of said drier. i 3\ 4. In a condensate removal device for a hollow cylindrical drier mounted with its axis* in substantially horizontal position, a normally stationary i receptacle extending longitudinally in said drer and projecting laterally from the central part of the same to collect condensate falling transverse the axis thereof, 'said receptacle being spaced from the peri'phery of the drier to receive condensate removed fromthe periphery 'by gravty and connections 'for removing condensate `from said receptacle,` arranged to 'retain at least a suflicient body of condensate to cause dropping of the condensate from the upper periphery of the drier.

5. In a condensate `removal device for a hollow cylindrical drier mounted with its aXis in substantially horizontal positiona normally stationary Conduit extending axially into said drier and having an intake opening adjacent to the lower periphery of said drier, a normally stationary receptaele ex tending longitudinally in said drier'and projecting laterally from the central part of' the same to collect condensate falling from the upper periphery thereof, said receptacle being spaced from the periphery of the drier to receive condensate removed from the periphery by gravity and copnec'tions for removing condensate from said receptacle and conduityarranged to retain at least a sufficient body of' condensate to cause dropping of the condensate from the upper I\ periphery of the drier.

6. In a conclensate reinoval device for a hollow cylinclrical drier mountecl ith its aXis in substantially horizontal position, a normally stationary concluit extenoling axially into one end of said drier, a normally stationary cl'ain pipe ext-ending axially within said drier, a receptacle extending longituclnally in said drier and projecting laterally froni said drain pipe near the axis thereof and spacecl a substantial distance froni the periphery thereof to collect conclcnsate ,falling freely within the clrier, said clrain pipe having openings to receive conclensate froni said receptacle and a connection for removing conclensatevfrom'saicl clrain pipe through said Conduit, arrangecl to retain at least a suficent body of conclensate to cause dropping of the conclensate from the upper periphery of the drier.

7. In a condensate renoval device for a hollow cylinclrical drier mounted with its axis in substantially horizontalposition, a normally stationary Conduit extending aX- ially into one end of said' drier, a clownwardly projecting pipe communicating with said conduitancl having an intake opening acljaoent to the'lower periphery of said clrier, a normally stationary drain pipe extencling axially within said clrier, a journal hearing for saicl clrain pipe supported on the end of said drier opposite said Conduit, a receptacle 'extenclng longituclinally in said drier and projeoting,` laterally from said drain pipe to collect conclensate falling within the clrier,

said dl'ain pipe having openings to receive condensate from said receptacleand a connecton for removing condensate from said dran pipe.

8. In acondensate removal device for a 40 hollow cylindrical drier mounted with its axis in suhstantially horizontal position, a normally stationary Conduit' ext-ending axially into one end of said' drier, a downwardly projecting, U-shaped pipe communicating With said concluitat one end and having an intake opening` adjacent to the lower periphery of said `drier, a normally stationary drain' pipe extending aXially within said drier and communicatng with said Conduit through said U-shaped pipe and a receptacle extencling longitudinally in said driei' and projecting laterally from said drain pipe to collect condensate falling within the drier, said drain pipe having openings to receive condensate from said receptacle.

In testimony whereof, I have hereunto signed my name to this s pecification.

ARTHUR E. BROUGHTON.

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