US2094038A - Steam drier system - Google Patents

Description

Sept. 28, 1937. A. G. KERNxN STEAM DRIER SYSTEM 2 Shee'ts-Sheet 1 Filed Aug. 24. 1936 RICE uw uhtbkmnzov Sept. 28, 1937. A. G. KERNIN STEAM DRIER SYSTEM Filed Aug. 24. 193e 2 Sheets-Shea t 2 5e/WN.

Patented Sept.` 28, 1937 UNITED STATES PATENT OFFICE Mosinee Paper Mills Company, y a corporation of Wisconsin Mosinee, Wis.,

Application August 24, 1936, Serial No. 97,617

2 Claims.

This invention relates to a steam drier system, and more particularly to a steam drum drier system for paper machines andthe like.

' In paper machine driers heretofore it has been 5 customary to employ steam traps or the like in the condensate drainage lines from the steam drier drums. In some instances the steam drier drums are divided into sections and the condensate together with steam discharged from one section into a steam separator, from which the steam is led into a second section of driers and the condensatefrom the second drier section discharged into another separator.' From this last separator, the steam may be fed to only a small number or one drier and the condensate therefrom exhausted into a vacuum pump or drained into a condensate tank.

According to my observations, steam traps frequently result in the circulation of steam being too sluggish for maximum efficiency of heat transfer from the drier drum shells to the paper be- -ing dried. Furthermore, in order to keep the machine operating at relatively eicient dryingV rates, continuous inspection of the system and replacement of parts are required. Often condensate from one section of driers is forced into another drier section owing to the diierence in pressure at which the various sections are operated, and this results in curtailed production owing to lack of proper drainage and ineiiicient heat transfer.

In accordance with the present invention, the condensate drainage lines are provided with members having xed orifices, which have a max- 3 imum capacity for the drainage of condensate but which allow a minimum passage of steam therethrough. When the drier system is in operation, the ow of condensate and excess steam is controlled solely by means of xed orices.

condensate in the rst section is then condensed in a dr-i'er or driers near the wet end or dry end, as preferred.

The drainage system of my invention comprises no movable parts, except a check valve in the line from the expansion chamber, or steam and water separator, to the condensate tank. Other valves The excess steam and flashed steam from the vention to provide a steam drier system for paper making machines and the like wherein the rate `of flow of condensate and excess steam from the drier drums is automatically controlled by members having xed orices and wherein the numtrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is a broken, somewhat diagrammatic side elevational view of a steam drier system for a paper making machine or the like, embodying the principles of my invention.

Figure 2 is an enlarged fragmentary view, partly in section, of a valved fitting having an oriced member for controlling the condensate drainage from a drier drum.

As shown o-n the drawings:

The reference numerals I0 indicate'a plurality of steam drier drums forming a part of the dry- 30 ing system of a paper machine or the like. It is customary to arrangethe paper drier drums I0 in two horizontal tiers, with successive drums in staggered relation, so that the paper to be dried V (not shown) passes successively around lower and 0 upper drums in a zigzag path through the drier section. It Will be understood, however, that my invention is applicable to other arrangements of drier drums and to drier systems other than paper making machine drying systems, as in the drying of fabrics and the like. l

As shown in Fig. 1, a number of felt driers II are positioned above the upper tier of paper drier drums but form a part of the same drying system. Steam is supplied through a pipe I2 to a steam header I3 and thence by means of individual pipes I4 to the paper driers I0 with the exception of the rst drier drum 25, located at the wet end. The felt driers II may be supplied with steam by individual pipelines leading from the header I3, as the pipelines I5, or, as in some instances, by a branch pipeline I6 from one of the paper drier pipelines Ida. Each of the steam pipes I 4, Illa, I5 and I6 vis provided with a valve I'I 5,. which is normally allowed to remain fully open when the drying system is in operation, but which is fully closed when the system is shut down, or when the drier controlled by such valve is desired to be shut off.

A condensate drainage line I8 extends from each 'of the paper driers I0 to a condensate return header I9. Similar condensate drainage lines 20 connect the felt driers II with said condensate header I9. In each of said condensate drainage lines I8 and 20 is positioned a fitting, designated by the reference letter A, which will later be described.

The condensate header I9 leads to an expansion chamber 2I for receiving the condensate and any steam that may pass into said header I 9. Said header I9 connects into the expansion chamber 2l near the top thereof, as at 22. A discharge condensate pipeline 23 is connected near the bottom of said expansion chamber 2|, as at 24, to return the condensate to the boiler feed line or to other desired points. The discharge pipeline 23 is arranged to discharge at a height suiiicient to give the desired pressure in the expansion chamber.

One or more of the paper driers at the wet end of the drier section, in accordance with my invention, is connected up somewhat differently from that described for the remaining driers. The iirst drier 25, for instance, is connected by a pipeline 26 to the upper end of the expansion chamber to receive ash steam from said chamber. The condensate from said first drier 25 is not led into the condensate header I9 but is discharged through a separate condensate pipeline 21 to a hot well or vacuum pump.

The fitting A will now be described. As best shown in Fig. 2, said tting A comprises a generally T-shaped body portion 33, one leg of which is provided with a threaded end 34 for receiving densate.

A valve 39 is interposed between the pipe I8 and the body of the fitting A, and a valve 40 is interposed between the pipe 36 and the body of the fitting A. Normally these valves are fully opened but are intended to be closed when the drier is shut down. The valve 40 may also be closed when it is desired to Withdraw condensate through the outlet 31.

An orificed plug 4I is adapted to be threaded into an opening 42 in the body portion of the tting A just beyond the valve 39 and between said valve 39 and each of the other valves 38 and 40. Said plug 4I is provided with a xed orice 43 of such dimensions as to take care of the maximum ow of condensate when the drying system is being operated under a predetermined set of conditions as to temperatures, pressures, speed of travel of the paper, etc. In order to provide for the replacement of the oriced plug 4I, the Wall portion of the fitting opposite said plug 4I is provided with an opening 44 of larger diameter than the opening 42 and having a removable plug 45 threaded thereinto.

When the drying system is operating, steam is supplied from the supply pipe I2 into the steam header I3 and from said header through the individual pipes I4 into the paper drier drums I0.

The pipelines I5 and I8 also conduct steam into the felt driers II. The condensate from said driers I0 and II is removed from said drums through the condensate lines I8 and 20, respectively, for drainage into the condensate header Il. From the header'IS, the condensate passes into the top of the expansion chamber 2 I, where some of the condensate is ilashed into steam and where any steam carried along with the condensate is separated therefrom, the condensate going to the bottom of said expansion chamber 2l and being exhausted therefrom through the pipe 23.

The steam thus separated from the condensate in the expansion chamber 2i vpasses under its own reduced pressure head through the pipe 23 into the rst drier drum 25, or there may be more than one such drum. Ordinarily the volume of the steam that is separated from the condensate in the expansion chamber 2| will' be suiiicient to heat only one, or possibly two or three, drier drums. The condensate from the drier drum 25 is drained into aseparate condensate pipeline 21, and then to hot well or vacuum pump. Y

Only a minimum amount of steam passes through the orifices 43 into the condensate header I 9. From the expansion chamber 2l the condensate is drawn through a pipeline 23, in which is positioned a check valve 50 to prevent any backow of condensate from the condensate tank (not shown) into the expansion chamber.

By closing the valve 40 and leaving the valves 39 and 38 opened, it is possible to measure the work done by each drier drum I0 by allowing the condensate to pass through the outlet 31 into a measuring vessel, or by weighing the condensate. The measuring vessel may be graduated in gallons or pounds so that the quantities o! condensate removed from the dried drums can be determined per unit of time. This is a very desirable feature since each drier drum can be separately tested and if it is not performing up to standard, steps can be taken to bring it back to its maximum operating capacity.

By the use of my system, it is very simple to arrange the driers to operate at any predetermined temperature by placing the proper sized orices in the condensate lines from the drier drums. 'I'he provision of the plugs 43 permits the oriflced plugs 4I to be readily replaced or exchanged for plugs having dlierent sizes of orifices.

As contrasted with the drying systems heretofore used, my system has only one movable part when in operation. Since the valves, with the exception of the steam supply regulating valve 5 I, are all normally in fully opened or closed position when the system is in operation. practically no supervision of the valves in the system is required. The check valve 50, of course, operates automatically, leaving only the regulating valve 5I in the steam supply line for adjustment by the operator during the operation of the drying system. It will be understood that in some drying installations there may be driers for the bottom drier felts and in that case, the bottom felt driers may be supplied directly with steam from the supply line I2 through a separate regulating valve, or the main regulating valve supplying steam to the regular paper driers.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. In a steam drier system having a plurality of steam driers, means for supplying steam thereto and conduits for the removal of condensate and steam therefrom, a branched structure in each of said conduits having an orificed member in said structure having an orice of reduced dimensions for controlling the ow of condensate and steam therethrough, a valve ahead of and a valve beyond said orice in branches of said structure and a removable closure member in said structure opposite said oriced member to facilitate the removal and insertion o1' such oriced member.

2. In a steam drier system having a plurality of steam driers, means for supplying steam thereto and conduits for the removal of condensate and steam therefrom, a. branched fitting in each of said conduits having an oriced member for controlling the passage of condensate and steam therethrough, a valve in said iitting ahead of said v orifice, a valve in each of two branches of said fitting beyond said orioe and a removable plug in said fitting opposite said orlced member to facilitate its removal.

ALFRED G. KERNIN.

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