US112422A - Improvement in steam-regulators for paper-driers - Google Patents

Description

DANIEL CROSBY, or HAMPDENMA1NE.

` www 'Letters Patentino. 112,422, dated March 7, 1871.

i `IMPROVEMENT IN STEAM-REGULATORS FOR PAPER-DRIERS.

The Schedule referred to in these Letters atent and making peut of the same.

I, DANIEL GROsBY, offHam pden, Penobscot county, Maine, have invented an Improved Steam-Regulator Y for Paper-machine Driers, and for other purposes, of

which the following is a'specification.

Figures 1,2, and 3 are sectional elevations of di'erent varieties of my invention.

. This invention has `for its object, generally, to obtain from a boiler the amountof steam, within which varies from time to time, a constant amount of steam within a vessel communicating with the boiler; and particularly to obtain from a boiler a constant amount of steam within the driers of a paper-machine, to the end that paper may be dried uniformly.

VThe 'invention consists in a:safety-valve, so arranged with reference tothe pipe by ywhich steam is conducted from the boiler to the driers as to regulate by its movementsthe admission of steam to the latter, allowing only enough to pass to maintain a constant quantity within the driers. y Referring to the drawinga are the driers of a-paper-machine, or the large hollow cylinders, around the perimeter-s 'of whichthe paper passes in a moist state,and which require to be kept filled with steam` in order tofurnish theheat y necessary for drying `the paper during its passage.

,b is the pipe by which steam is admitted to the driers.- y i Y In order to securewithin the driers a constant supply of steam, either of two mechanisms may heemployed,' which, though differing to some extent in construction, are alike in" prnciple one of which mechanisms is shown infigs. l 'and4 2, and the other in hg. 3, both of them agreeing in this, that the steam from the boiler, `before entering the driers, hasA to pass a safety-valve, by the-movements of which therequisite constancy of supply is obtained. i

In figs.- l and 2, A is the\pipe by which steam is l `taken from the boiler, and in which the quantity of' l steam'varies, the same as `in'the boiler, the said pipe opening directly into tbepipe b. Within the latter are placed two disks, c c', both fitting the pipe closely, one above and theother below the mouth ofthe pipe A, said disks being` rigidly attached to a stem, d, which extends through a stungfbox, d', located in the up-` per end of the pipe b, and at its top is jointed to. the

extremityof the shorter arm of` a lever, c, which h as its fulcrum in a standard, f, that springs from a strap, g, which passes across and projects to either side of the open top of a-verticalpipe, 71 thatis connected with thefpipe `b by' means ot' horizontal pipes t, which ppen into the vpipe b one above the upperdisk c and :the other below the lower disk c',

i Withintheupipe his located a safety-valve, 1c, the stem l of whichpasses through the strap g, and is jointed at itsl upper end` to the longer arm ofthe lever e, to the extremity of which theweight m is hung, the said lever being guided in its vibrations by a slotted standard-n, springing from the strap g, through which standard the lever e passes'. l

`It will be' observed that the disks e c' are at one sideof the fulcrum of the` lever e, and the valve 7c at the other side, soth'at when one rises lthe other must Before steam enters the pipe b, the weight m has raised the disks c c' so far that the upper disk is above itsseat, say half an inch, when the diameter of the pipe A is one and one-quarter inch, leaving an open-4 ing beneath said upper disk, through which steam may ow. Theflower disk c' is never raised to the level of the pipe A,and consequently no steam ever flows be- 'heath it. l

i Th'eweght m should be placed at a point on the lever where it may exert on the stem l a pressure nearly equal to that which it is desired should always be exerted by steam on the valve k, allowance being made for thefriction ofthe valve-stems and lever.

The pressureof steam on the valve k is to be kept as nearly as possible constant. If five pounds to the square inch be the pressure desired for the safetyvalve, the weight m should be stationed so as to draw downward upon the stem l with a force nearly equal to the number of square inches in the area ofthe valvemultiplied by ive.

The moment the steam from the boiler owing past the upper' disk c exerts upon the safety-valve a pressure greater than that for which it is weighted, the safety-valve rises, the disks c c at the same time descending and cutting olf the supplyof steam.

When the upper disk arrives at its seat the two `disks together constitute a balanced valve, so that when' the pressure within the pipes T) h i falls below the amount for which the safetyvalve is weighted, the latter descends, the disksc c' rise, and the disk c again admits steam into the pipe b. As soon as the pressure upon the safety-valve again exceeds the-prescribed limit, the steam is once more shut off as before, and as soon as the pressure again falls below the prescribed limit, steam is once more admitted as before, and thus the process goes on, tbe result being the keeping of a nearlyconstant quantity of steam in the driers.

. In fig. 2-is shown a slightly dil'erent arrangement, the pipe h not being connected directly with the pipes c', but being connected a't its lower end by a tube, o, with the bottom of a chamber, @into the top of which the upper pipe i opens.

l The pipe o is iilled with mercury, of which there is a quantity sucient to also ll the chamber/r. rlhe oihce of the mercury is simply that of a packing, to prevent. the escape of any steam past the safety` valve, the operation of the. latter' being the same as in the apparatus shown in iig. 1.

In iig. 3 the safety-valve la is shownas discharging, in addition to the office hereinbefore assigned toit, that also of the balanced valve ,c the latter being in this instance dispensed with, as also is rthe whole system 0f pipes i h, the safety-valve being made not only to perform the functions of the balanced valve c c', but also to occupy its position in the pipe b, which in this case is devoid of the stufing-box b', and is open at the top, except in so far as the strap g covers it.

The valve k forms'the headtof a tube, k, which closely iits the inside of the pipe b, and extends downward therein past the mouth of the pipe A, said tube having on the side next the pipe A an orifice, k2, of the same diameter as the pipe, and being open at its lower end.

Prior to the admission of steam, the tube k is held down by the weight m so -far in the pipe b that the orifice k2 forms a continuation of the pipe A;' but after steam has entered the pipe b, as soon as it presses upon the valve k with a force greater than that of the weight lm, the valve rises, and the tube h1, closing the mouth of the pipe A, shuts off steam from the pipe b.

As soon as the pressure within the latter falls below that of the weight, the valve descends and admits more steam. r)This apparatus has the advantage of being more simple than the latter, and is, perhaps, equally ecient.

I claim as .my invention- A safety-valve, arranged, substantially as described, with reference to the pipe by which steam is conducted from a boiler to the driers of a paper-machine or any other vessel that communicates with the boiler, as to regulate by its movements the admission of steam to such vessel, allowing only enough to pass to maintain a constant quantity within the latter.

DANIEL CROSBY.

Witnesses:

E. J. DUDLEY, J oHN CnosBY.

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