US2934831A

US2934831A - Self-positioning siphon scraper for drier drums

Info

Publication number: US2934831A
Authority: US
Inventors: Tasker Frederick
Original assignee: SMITH PAPER MILLS Ltd HOWARD
Current assignee: HOWARD SMITH PAPER MILLS Ltd; SMITH PAPER MILLS Ltd HOWARD
Priority date: 1957-10-14
Filing date: 1957-10-14
Publication date: 1960-05-03
Anticipated expiration: 1977-05-03

Description

F, TASKER SELF-POSITIONING SIPHON SCRAPER FOR DRIER DRUMS v med 0ot.-l4 1957 2 Sheets-Sheet 2 INVIIIM Frederick MSKER I afranu SELF-POSITIONIN G SIPHON SCRAPER FOR DRIER DRUMS Frederick Taslrer, Donnacona, Quebec, Canada, assignor to Howard Smith Paper Mills Limited, Montreal, Quebec, Canada Application October 14, 1957, Serial No. 690,138

3 Claims. (Cl. 34-125) The present invention relates to an improved device for removing the water of condensation from steam heated drier drums, such as used in the textile and paper making industries. The efficient removal of water from drier drums have been the subject of much study and several designs of siphon tubes have been proposed. In conventional siphon tubes, the inner vertical leg is stationarily mounted within the rotating drum and extends in close proximity with the internal face of the drier shell, but

does not contact the same. Thus, there is a gap left between the internal face of the drier shell and the inlet of the siphon tube and a substantial depth of water has to be provided at the bottom of the shell in order to remove the water in a continuous stream.

When too much condensate water is left in the drum this water tends to form, under centrifugal force, a layer on the inside wall of the drum which is heat insulating and considerably decreases the heat transfer efliciency of the steam to the web being dried on the outside of the drum.

Also, when too much water is allowed to accumulate in the drier drum, the water layer tends to drop to the bottom of the drum to be again lifted thereby resulting 'in a considerable expenditure of power and non-uniform power consumption.

Accordingly, the general object of the present invention is the provision of a siphon device for drier drums which will continuously remove the condensate water from within the drum as quickly as it is formed, thereby practically eliminating, or at least reducing to a very small thickness, the condensate layer formation on the inside face of the drier shell thus aiding in a better heat transfer to the outside of the drier shell and also eliminating the surges in power requirements normally caused by the continuous lifting and dropping of the water inside the drum.

The siphon head, in accordance with the present invention, is characterized by the fact that it is in continuous contact with the inside wall of the drum and, therefore,

exerts a scraping action which results in the collection of all the water in the path of the siphon head and removes the same thereby maintaining the amount of condensate inthe drum to an absolute minimum.

Still another important object of the present invention is the provision of a siphon device of the character described in which the siphon head is telescopically mounted with respect to the remaining part of the siphon to allow continuous contact of said head with the internal face of the drum during rotation of the latter despite possible eccentricities or irregularities of the internal face of the drum shell and despite possible eccentric mountings of the central tube extending through the hollow trunnion of the drum.

' Yet another important object of the present invention 'is the provision of means to maintain the inlet mouth of the siphon head in constant and proper position with respect to the direction of rotation fo the drum.

ttes Patent C The foregoing and other important objects of the present invention will become more apparent during the following disclosure and by referring to the drawings in which:

Figure 1 is a cut-away partial perspective view of a rotary drum drier provided with the siphon scraper in accordance with the present invention;

Figure 2 is an enlarged perspective view of the siphon scraper;

Figure 3 is a partial longitudinal section of the drier drum showing the siphon scraper; and

Figure 4 is a longitudinal section of the siphon assembly.

Referring now more particularly to the drawings in which like reference characters indicate like elements throughout, the drum is generally indicated by the reference numeral 1 and comprises a cylindrical wall or shell 2 which is closed at both ends by radial head walls 3 provided with coaxial hollow cylindrical extensions 4 forming trunnions for the drum, for rotation of the same about its longitudinal axis. The trunnions 4 are journalled in suitable bearings (not shown) and means (not shown) are provided to rotate the drum. A steam supply pipe 5 extends through at least one of the trunnions 4 and proiects into the interior of the drum drier 1. The steam supply pipe 5 is stationarily mounted at its outer end in any conventional manner (not shown) and is connected to a supply of steam. The inner end 6 of the said pipe 5 is provided with openings 7 for the admission of steam under pressure inside the drier 1. The inner end 6 of the steam supply pipe 5 forms seating surfaces for the pivotal engagement of a member 8. The member 8 is arranged for pivotal movement in a vertical plane containing the long axis of the drier 1, but movement of the member 8 in a plane perpendicular to said axis is completely prevented.

The member 8 is hollow and is provided with a downward sleeve 10 provided with lateral flanges 11 for tightening the sleeve by means of the bolts 12 around a tube 13 which forms the upper part of the siphon scraper in accordance with the present invention. The upper portion of the member 8 is also provided with a threaded axial opening 14 for threaded engagement with a con densate drainage tube 15 which extends coaxially within the steam supply pipe 5 and projects outwardly of the trunnion 4 and is connected to a downward extending drain pipe for draining the water of the condensation out of the drier drum.

The lower section of the siphon scraper consists of a second tube or sleeve 16 in telescopic engagement with the lower portion of the tube 13 and provided at its lower end with a transversely extending triangular plate 17. Scraper members 18 are removably secured to two sides of the triangular plate 17 as by means of bolts 19. The scraper members 18 are preferably made of a thermosetting resin, such as phenolic resin, and are adapted to be in sliding contact with the inside face of the cylindrical shell 2 of the drier 1. The scraper members 18 meet'with each other at 20 in the rear apex of the triangular plate 17 and. are bevelled at their forward edges, as indicated at 21, to merge with the ends of the front side 22 of the triangular plate 17.

In order to prevent rotation of the sleeve 16 on the tube 13 while allowing telescopic movement of said sleeve, guiding means are provided which comprise two collars 23 rigidly secured to the tube 13 and holding a rod 24 in spaced parallel relationship with the tube 13 and sleeve 16 at the back of the siphon scraper. The sleeve 16 is provided with a rearwardly extending flange 25 having a bore for slidably receiving the lower end of the rod 24;

The lower edges of the scraper members 18 may be ing has been illustrated and described, said mounting could be modified.

In the embodiment described, the size of the siphon head comprising the triangular plate 17 and scraper members 18 is such as to pass through the hollow trunnion 4 of the drier drum 1. Thus the siphon can be inserted within the drum by pushing the assembly of the axially aligned steam tube 5 and siphon scraper through the trunnion 4. Upon reaching the interior of the drier drum, the siphon scraper pivots about the inner end' 6 'of the steam supply tube 5 into a vertical position in which the threaded opening 14 of the member 8 faces axially of the steam supply tube 5. Therefore, it is possible to insert the condensate drainage tube 15 through the'tube 5 and thread the same into the opening 14. Both tubes 5 and 15 are held against rotation at their outer ends projecting from the trunnion 4 and, therefore, tube 5 in turn prevents rotation of the siphon scraper within the drum 1.

It is understood that the scraper head may be made wider than actually shown in the drawings and that it may be positioned inside the drum through a manhole made in the head wall 3 of said drum, in which case there will be no need for the provision of the pivotal joint at the inner end 6 of the steam supply tube 5.

During rotation of the drum, the scraper members 18 slide against the internal face of the cylindricalshell 2 and the telescopic arrangement of the sleeve 16 with respect to the tube 13 allows for any eccentricity or irregularity of the cylindrical shell 2 and also for any eccentricity in the mounting of the steam supply tube 5. Also, the guiding means 23 to 25 maintains the mouth of the scraper in a plane parallel to the long axis of the drum and facing against the direction of movement of the part of the cylindrical shell opposite said head. Thus the water of condensation in the path of the head enters the head through the mouth thereof, rises through the sleeve 16 and tube 13 and is discharged to the exterior through the condensate draining tube 15. The scraping action of the members 18, in sliding contact with the inside face of the cylindrical shell 2, positively removes all the water in the path of the scraper head and, therefore, the water in the remaining parts of the drum flows under gravity to the scraper head to be removed thereby.

The opening 27 of the lower end of the sleeve 16 at the triangular plate 17, is preferably calibrated in such a manner that the water will be only removed from the drum at such a rate as to substantially prevent escape of steam. It will be noted that the triangular plate 17 and scraper members 18 form, together with the shell 2,

a tapered box having a wide mouth; therefore, the water entering said box backs up to a higher level than actually existing in the remaining part of the bottom of the drum l-whereby the water in the head is in constant communicationllwith the inlet 27 of the sleeve 16 and the water is removed as a continuous stream.

When the scraper members 18 are worn out, they can be easily replaced by unscrewing the bolts 19.

While a preferred embodiment in accordance with the present invention has been illustrated and described it is understood that various modifications may be resorted to without departing from the spirit and scope of the appended claims.

I claim:

1. A steam condensate siphon assembly for removing the water of condensation from a high speed rotating drier drum into which steam is introduced to heat the drum comprising, in combination, a self-positioning condensate collecting scraper disposed in scraping contact with the inside surface of the bottom portion of the rotating drum and movable vertically in the drum to maintain continuous scraping contact therewith despite eccentricities or irregularities of the inside drum surface and without subjecting component parts of the siphon assembly to stresses or strains likely to cause breakage thereof and means holding said scraper against rotation with the drum including a siphon tube having its lower end rigidly connected to the scraper to receive condensate therefrom and extending upwardly from the scraper, said siphon tube including upper and lower telescopic sections which are slidably fitted together but are held against turning movement about their central longitudinal axes, and tube mounting means through which condensate is delivered from the tube to a delivery point exterior of thedrum.

2. A steam condensate siphon assembly for removing the water of condensation from a high speed rotating drier drum into which steam is introduced to heat the drum comprising, in combination, a self-positioning condensate collecting'scraper disposed in scraping contact with the inside surface of the bottom portion of the rotating drum and movable vertically in the drum to maintain continuous scraping contact therewith despite eccentricities or irregularities of the inside drum surface and without subjecting component parts of the siphon assembly to stresses or strains likely to cause breakage thereof and means holding said scraper against rotation with the drum comprising a siphon tube including an upper tube section and a lower tube section which telescopes the upper tube section and is slidable vertically relative to said upper tube section, said lower tube section having its lower end rigidly secured to said scraper, means for holding said lower tube section against turning movement about its own longitudinal axis and tube mounting means through which condensate delivered to the tube by the scraper is discharged from the tube to a delivery point exterior of the drum, said tube mounting means being secured in a fixed position and being connected to the upper tube section to hold the latter against rotation with the drum and also against turning movement about its own longitudinal axis. a a

3. A steam condensate siphon assembly as set forth in claim 2, in which the means for holding said lower tube section against turning movement about its own longitudinal axis comprises a guide rod fixedly secured to one tube section and extending longitudinally thereof and a rod receiving element fixedly secured to the other tube section and having a guide opening in which said rod is slidably fitted.

References Cited in the file of this patent UNITED STATES PATENTS 267,666 Brigham Nov. 21, 1882 1,537,792 Aucutt May 12, 1925 1,806,081 Pratt May 19, 1931 2,297,094 Armstrong et al Sept. 29, 1942 2,617,205 Cram Nov. 11, 1952