US2707836A - Paper machine drier drum - Google Patents

Description

May 10, 1955 Filed July 1, 1954 F. A. GARRETT 2,707,836

PAPER MACHINE DRIER DRUM 3 Sheets-Sheet 1 IN V EN TOR.

FRANCIS A- GARRETT BY y 1955 F. A. GARRETT PAPER MACHINE DRIER DRUM Filed July 1, 1954 3 Sheets-Sheet 2 INVENTOR.

FRANCIS A-GARRETT May 10, 1955 F. A. GARRETT PAPER MACHINE DRIER DRUM 3 Sheets-Sheet 3 Filed y 1, 1954 INVENTOR. F RA'NC l5 A-GA RRETT Q mm W Kai K bx Qgenf.

United States Patent M PAPER MACHINE DRIER DRUM Francis A. Garrett, Three Rivers, Quebec, Canada, as-

siguor to Canadian International Paper Company, Montreal, Quebec, Canada, a corporation of Canada Application July 1, 1954, Serial No. 440,809

3 Claims. (Cl. 34-124) This invention relates to new and useful improvements in drying equipment for papermaking machines and particularly seeks to provide novel means for efficiently removing condensate from individual drier drums or cylinders.

The rate and uniformity of the drying of fibrous sheet materials or paper such as newsprint on drum driers is substantially influenced by the manner in which the heating steam is admitted to and the condensate removed from the individual drier cylinders.

Steam is customarily introduced into such cylinders through one journal in an axial direction and at low velocity. Generally no special distributing devices are employed, although some installations have used a central pipe or header extending from journal to journal, provided with a number of large diameter perforations which cause steam to be admitted to the interior of the drum in a radial direction at low velocities.

Drier drums constructed in accordance with this invention not only provide greatly improved distribution of steam through the use of a great number of small diameter, high velocity jets, but also provide novel and eflicient means for removing the condensate.

Therefore an object of this invention is to provide a novel device for drier drums by which condensate may be rapidly and eificiently removed therefrom.

A further object of this invention is to provide a device of the character stated which includes a plurality of siphon tips secured adjacent the inner face of a drier drum and connected to a condensate return pipe positioned within the steam supply header.

A further object of this invention is to provide a device of the character stated in which each siphon tip includes a duct of rectangular cross section having its entrance of the least possible height without causing plugging and itswidth such that the velocity of steam passing therethrough will be substantially in excess of 1000 F. P. M. when the ratio of conveying steam to conveyed condensate is -1 lb. to 3 lbs.

A further object of this invention is to provide a device of the character stated which is simple in design, rugged in construction and economical to manufacture.

With these and other objects in view, the nature of which will be more apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description and the appended claims.

In the drawings,

Fig. 1 is a front elevation of a drier drum into which is incorporated a condensate siphon constructed in accordance with this invention;

Fig. 2 is an enlarged vertical transverse section thereof;

Fig. 3 is an enlarged fragmentary vertical transverse section showing the manner in which heating steam is admitted to the drier drum;

Fig. 4 is an enlarged horizontal section taken along line 4-4 of Fig. l;

2,707,836 Patented May 10, 1955 Fig. 5 is a top plan view of the siphon tip;

Fig. 6 is a vertical longitudinal section taken along line 66 of Fig. 5;

Fig. 7 is a bottom plan view of the inlet end of the siphon tip;

Fig. 8 is a vertical transverse section taken along line 8-8 of Fig. 6; and

Fig. 9 is a vertical longitudinal section taken along line 9--9 of Fig. 5.

Referring to the drawings in details, the invention as illustrated is embodied in a drier drum generally indicated at A which includes a cylindrical shell 5, end headers 6, 6 firmly bonded to the ends thereof, and a stub shaft 7 extending outwardly from each of the headers 6; The right-hand stub shaft 7 is hollow and is connected as through a suitable gland 8 (see Fig. 1) to a steam supply pipe 9.

A steam header pipe 10 extends between the inner ends of the stub shafts 7, 7 within the shell. 5 and has its left end as viewed in Fig. 4 plugged as at 11. It will be noted that preferably the inner end of the left-hand stub shaft 7 is closed by a disc 12. I

The steam header 10 is provided with a plurality 0 rows of small diameter apertures 13 through which steam supplied through the supply pipe 9 can leave the header tube 10 as a multiplicity of high velocity jets for entrance into the interior of the shell 5. The diameters of the apertures 13 are such that the steam will pass therethrough at a velocity in excess of 1000 F. P. M. Through the use of high velocity steam jets in this man-. nor the steam which is admitted to the interior of the shell 5 impinges against the inner surface thereof and as a result of having employed a great number of small diameter jets the steam emanating therefrom will also become thoroughly intermingled and will provide substantially uniform temperatures along the entire surface of the shell.

As the steam cools condensate will, of course, be formed, and in order that the over-all heating eificiency of the drier may be maintained at the highest practicable operating levels eflicient means for the removal of the formed condensate must be provided. To this end a plurality of siphon elements B are affixed within the shell 5 to the inner surface thereof. By reference to Figs. 2 and 4 of the drawings it will be seen that each siphon element B is positioned adjacent the inner surface of the shell 5 and is braced in such position by a radially extending rod 14.

Each of the siphon elements B comprises a generally rectangular casting 15 of shallow depth. The entrant end, i. e., the right-hand end as viewed in Figs. 5 and 6, is provided with an upwardly flared mouth portion 16 to admit steam and conveyed condensate to a relatively wide and low rectangular orifice 17 which opens into communication with a pair of relatively long and narrow upwardly slanting passages 18, 18. The passages 18 in turn extend into open communication with a discharge chamber 19 which is connected to a condensate removal. pipe 20 (see Figs. 2, 4 and 6) which conveys the condensate and its conveying steam to a main condensate removal pipe 21 positioned along the axis of the perforated header 10 and which is connectedto an externalcondensate removal pipe 22. for return back into the over-all steam system.

The orifice 17 serves two purposes: First, it serves to atomize the condensate; and second, it serves to control the rate of steam flow used to convey the condensate. A plurality of siphon elements have been employed in order to shorten the distance through which condensate must flow.

The depth of the orifice 17 should be the least possible that can be used without causing plugging. Its width 3 should be such that the velocity of steam passing therethrough 'will be 1000 F. 'P. M. or more when the ratio of conveying steam to conveyed condensates is 1 lb. to 3 lbs.

As already mentioned, the siphon elements 113 and the orifice 17 thereof are disposed adjacent the inner surface of the shell 5. In the embodiment illustrated in the drawings each element B is so constructed that the orifice 17 thereof is defined by the smooth inner surface of the shell 5 and the appropriate routing out or grooving of the'casting 15. Thus the orifice 17 .has its area disposed wholly inside but adjacent to the inner surface of the shell 5. It is, of course, conceivable that the casting 15 may have its entrant end 16 so shaped that the upper face of the orifice 17 would be tangent to the plane of the inner face of the shell 5 and that in order to actually define an orifice the material of the shell 5 would have to be milled out. Even if this were done an orifice so created would function in "the 'same manner as that described above in connection with the form of orifice illustrated in the drawings.

In practical operation of drier drums having steam admission and condensate return means constructed in accordance with this invention the apertures 13 of the header tube 10 could be on the order of from 0.089"

0t 0.166", and the dimensions of the orifice 17 could "be of a-width extending from 0.750" to 2.000" in order to provide velocities therethrough which will fall in the range substantially in excess of 1000 F. P. M. and preferably within the range of 9,500 to 22,000 P. P. M.

It will be noted from the foregoing description that a drier drum containing steam intake and condensate removal devices constructed in accordance with this invention is markedly different from any devices in use today for the same purpose. It is believed that this is the first time that steam has been admitted to the interior of a drier drum as a multiplicity of very high velocity jets and that this is the first time that anyone has provided means for removing condensate in atomized form.

It is, of course, to be understood that various details of arrangements and proportions of parts may be modified within the scope of the appended claims.

I claim:

1. 'In a drier drum for paper machines wherein is provided a hollow shell, end closures for said shell, an outwardly extending stub shaft rigidly a-fiixed to each of said end closures, one of said stub shafts being hollow, and -'a steam supply pipe connected with said hollow stub shaft; the combination of an axially aligned steam header pipe affixed between said end closures and having one end extending into-open communication with the bore of said hollowstub shaft, said steam header pipe being provided with a multiplicity of radially extending apertures arranged in a series of equally spaced rings along the length thereof, the diameters of said apertures being Within the range of 0.089" to 0.1 66" whereby to cause steam to be admitted to the interior of said shell as a multiplicity of jets each having a velocity of from about 9,500 to about 22,000 P. M., a condensate return pipe positioned within said steam header pipe and extending axially through said hollow stub shaft, a plurality of condensate-removing siphon tips secured adjacent the inner surface of said shell, each of said siphon tips being provided with an entrant orifice of sufiiciently small area that the condensate passing therethrough will be removed as :an atomized spray having a velocity of from about 4 9,500 to about 22,000 P. P. M., and means for connecting said siphon tips with said condensate return pipe.

2. In a drier drum for paper machines wherein is provided a hollow shell, end closures for said shell, an outwardly extending stub shaft rigidly afiixed to each of said end closures, one of said stub shafts being hollow, and a steam supply pipe connected with said hollow stub shaft; the combination of an axially aligned steam header pipe affixed between said end closures and having one end extending into open communication with the bore of said hollow stub shaft, said steam header .pipe being provided with a multiplicity of radially extending apertures arranged in a series of equally spaced rings along the length thereof, the diameters of said apertures being within the range of 0.089 to 0.166 whereby to cause steam to be admitted to the interior of said shell as a multiplicity of jets each having a velocity of from about 9,500 to about 22,000 P. P. M., a condensate return pipe positioned within said steam header pipe and extending axially through said hollow stub shaft, a plurality of condensate-removing siphon tips secured adjacent the inner surface of said shell, each of said siphon tips being provided with a rectangularly cross-sectioned entrant orifice having the least possible depth that will prevent plugging and a width of from about 0.75 to about 2.00" whereby the condensate passing therethrough will be removed as an atomized spray having a velocity of from about 9,500 to about 22,000 F. P. M., and means for connecting said siphon tips with said condensate return pipe.

3. In a drier drum for paper machines wherein is provided a hollow shell, end closures for said shell, an outwardly extending stub shaft rigidly atfixed to each of said end closures, one of said stub shafts being hollow, and a steam supply pipe connected with said hollow stub shaft; the combination of an axially aligned steam header pipe afiixed between said end closures and having one end extending into open communication with the bore of said hollow stub shaft, said steam header pipe being provided with a multiplicity of radially extending apertures arranged in a series of equally spaced rings along the length thereof, the diameters of said apertures being within the range of 0.089" to 0.166" whereby to cause steam to be admitted to the interior of said shell as a multiplicity of jets each having a velocity of from about 9,500 to about 22,000 P. P. M., a condensate return pipe positioned within said steam header pipe and extending axially through said hollow stub shaft, a plurality of consensa'teremoving siphon tips secured in contact with the inner surface of said shell, each of said siphon tips being provided with a rectangularly cross-sectioned entrant orifice one wall of which is defined by the inner surface of said shell, said orifice having the least possible depth that will prevent plugging and a width of from about 0.75" to about 2.00" whereby the condensate passing therethrough will be removed as an atomized spray having a velocity of from about 9,500 to about 22,000 F. P. M., and means for connecting said siphon tips with said condensate return pipe.

Rcferences'Cited in the file of this patent UNITED STATES PATENTS l,486,ll2 McCracken Mar. 4, 1924 2,049,050 Cram July 28, 1936 2,617,205 Cram Nov. 11, 1952 2,677,898 Ohlson et al May 11, 1954

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