US215946A - Improvement in automatic feed for paper-machines - Google Patents

Description

J. T. P. MacDONNELL. Automatic Feed for Paper-Machines.

No. 25,946. Patented May 27, 1879.

.Plan %m Secila/z y y.

?VIT/mases.- I I I UNITED STA ES PATENT OFFICE.

JOHN T. F. MAC DONNELL, OF HOLYOKE, MASSACHUSETTS.

MPROVEMENT IN AUTOMATIC FEED FOR PAPER MACHINES.

Specification forning part of Letters Patcnt No. 2141946, dated May 27, 1879; application filed May 27, 1878.

To all whom it may concem:

Be it known that I, JOHN T. F. MAC DON- NELL, of Holyoke, in the county ot' Hanpden and State' of Massachusetts, have inven ted certain Improvements in Automatic Feed for Paper-Machines, of which the following is a specification.

The object of my invention is to secure the -delivery of the pulp or stuff in a paper-machine of a uniform consistency, in order to insure auniform thickness of the paper produced and to this end the invention consists in a method and apparatus in which the varying specific gravity of the stuff is caused to control the admission of the water used to reduce it.

My invention is capable of application to going through all the preliminary p'rocesses,

of reduction to pulp, reaches what is termed the stilit-chest, which is a large tank or receptacle containing agitators to keep the contents of uniform consistency and prevent the .separation and settling of the heavier portion. From this stuff-chest the contents are pumped, by a pump connected with the machine, into what is called the stuff-box, a stream of pure water being allowed to flow into the box when desired, and dilute the stufi before it passes to the machine proper and to the wire cloth, where the water is removed and the pulp left in the sheet form.

It is obvious that with a given quantity of stufi' passing out in a given time to the machine the paper resulting will vary in thickness as the stufi pumped into the stuff -box from the stuff-chest is thicker or thinner in consistency.

In practice it would be impossible for the attendant to preserve a uniform consisteney of stuff by his own observation and tests with such accuracy as to insure a uniform thickness ,it wrong, the flowing mixture has been and is still going out to the machine, .and consequently the sheet rendered too thick or too thin, while he has been testing and before he can remedy the difficulty.

Various attempts have been made to control automatically the flow of the stuff from the stuff-box, such as the use of self-regulatin g Valves, &c., and thus to control the thickness of the sheet; but in practice the attempts have all resulted in failure.

In order to secure the desired result,`l avail myself of the varying weight of the contents of. the suff-box due to the changes which occur in the specific gravity of the stut' according as it contains more or less pulp or water' in proportion to each other.

The stuff-box in ny invention is always full to a certain height, the required amount passing from it to the machine, and the residue flowing back into the stuff-chest.

In practice we find that the specific gravity of the stuff or stock is greater than that of the water used to dilute it, and, consequently, that the weightof the contents of the stuff-box, although remaining the same in Volume, will be greater or less, according as the proportion of water therein is ncreased or diminished. In order to make use of this fact, I nount the stuff-box on a scale-beam, or otherwise support it so that it is niccly balanced when filled with stuff ot' the exact consistency desired, and so arrange a water-supply pipe and other parts that whenever the' material becomes too thin,

and consequently lighter, the counter-,weight will elevate the box and cause the flow of water to be dininished, while'at, the same time the inward fiow of stuff continues, so as to bring the contents of the box to the proper consistency. If, on the other hand, the material in the stuff-box should becone too thick,

and so much heavier than if of the proper consistency, the box and contents will overbalance the counter-weight and cause the flow of water to be increased, and thus restore the proper consistency.

The accompanying drawings represent one form of apparatus which may be employed for carrying out my invention.

A represents the stuff-box, provided on its sides with trunnions a, supported in the arms of a forked scale-beam, B, which is pivoted at the point c and provided with a slidi g weight, O, which is so adjusted as to counterbalance the weight of the box A and its contents when the latter is of the desired consistency. .D represents the spout through which the stufl' is discharged into the stuff-box A to dilute its contents, the pipe E, in the present case, being arran ged directly below the stuffspout D, with its end in line with the side of the box A, so that the latter may traverse verticall y past its mouth.

During the proper operation of the machine the stuff or pulp is discharged through the spout D in a continuous stream into the box A, and a continuous stream of water also discharged through the pipe E into the box A to reduce or dilute the stock to a proper degree of fiuidity, the rcduced mass flowing under the partition d and up into the narrow space between the partition d and the end of the stuff-box, from which space the proper quantity is allowed to flow out to the machine through an opening controlled by a gate or gage, while any surplus over and above the normal Volume of contents flows over the ends of the said narrow space and finds its way back to the stuff-chest.

The use of the partition is important and advantageous in that it insures an even mixture of the water and stock, and that it securcs the delivery of the stock of' constant cousistency from the box, although that in the body of the box separated by the partition may have a slight temporary variation.

It is to be understood that when the box and its contents are in equilibrium with the counterpoise i. e., where the stuf in the stuffbox is of just the right consistency-the adjustment of parts will be such that about onehalf of the full flow of the water-pipe E will enter the box.

Whenever the contents of the box A become diluted beyond the extent (lesired the specific gravity and weight of the mass are lessened,

whereupon the weight 0, preponderating over' the weight of the box, causes the latter to ascend and diminish the inflow of water from the water-pipe E, the flow of pulp meanwhile continuing. As the mass attains the proper consistency again the increased weight causes the box to descend, and the inflow of water will be increased. In like manner, if the stuff in the box becomes too thick, the resulting downward movement of the box will produce a larger inflow of water, thus dilutin g, and consequently lightening, the contents of the box,

which will again rise to its normal height when the proper consistency is attained.

In practice thebox is to be so accurately counterpoised that it will at once be actuated by any change in the weight of its contents, and respond so readily that any variation in the consistency of the stuff will at once be corrected.

Thus it will'be seen the admission of the water and the consistency of the pulp are regulated automatically and With great nicety, and the stuff delivered from the box of a uniform consistency.

In the drawings the stuff-pipe D is represe'nted as discharging from a small box or chamber, F, into which the stuff is pumped from the stuff-chest, it being thought preferable to pump the stuff into this intermediate chamber F rather than directly iuto the stuffbox A. A

For the purpose of limitin g the vertical motiou of the stuf-box a slotted standard, c, is mounted at one side of the box to receive a stop-pin f, on the latter, as shown.

It is obvious, ,as above stated, that the arrangement of' the details may be modified to any extent desired, provided the principle of operation of the apparatus is not changed. Instead of having the upper edge of the box A arrauged to traverse up and down before the mouth of the water-pipe E, it may be connected in any suitable manncr with a valve arrangca to regulate the ,discharge from said 1 e. p i further obvious that instead of controlling the consistency by limiting the flow of water into the box, the same result may be accomplished by permitting, and at the same time controlling,a flow of water out of the stufl`-box; but this plan is not considered a desirable one for practical use.

While it is prcferred to employ the balanced box, to be moved by variations in the specific gravity of the stuff, it is obvious that the box may `be made stationary and a properly d. justed float mounted therein and connected with a valve or other device for regulating the admission of water to the stuff in which the float is mounted, so that as the specific gravity of the stuif is reduced by an excessive dilution the float will sink deeper, and thereby diminish the flow of water, and tas the specific gravity is increased again the float will be buoyed higher and caused to increase the flow of water.

It is also obvious that instead of balancing the 'stuff-box, a special regulating-box may be introduced into the machine and balanced in the same manner, for the purpose of controllin g the dilution of the stuff.

I do not confine myself to any particular form of stuff-box or to any special device for controllin g the outflow of stuff from it, as my invention is applicable to all the different arrangements in use for those purposes.

I am aware that attempts have been made to regulate the thickness of the web or sheet in a paper-machine by regulating the flow of stock thereto, the flow being reduced as the stuff increased.

I am also aware that an attempt has been made to secure the same end through the instrumentality of abalanced fiexible diaphragm,

over which the stock was cansed to flow in a thin stream, and upon which the stock accumulated to an increased extent as it became thicker, the diaphragm being connected with a gate to regulate the flow, and with a Valve through which water was discharged into that portion of the stock which had passed beyond the diaphragm into a feeding-chambcr. This arrangement, besides requiring an expensive and complicated apparatus, and necessitatin g a constant return of a portion of the stock to the feeding nechanism, was objectionable and inefficient, for the reason that it did not secure a uniforn consistency of the material, the water being introduced, not into the thickened portion of the stock upon the diaphragm, but into the stock which had already passed the same, and which was of the proper consistency, the consequence of which was that the stock, as delivered to the machine, varied con stantly in consistency, being first too thick and then too thin. Besides, it was found that the Variation in the flow, to compensate for variations in the consistency, required a delicacy of adjustment which was in practice impracticable.

Now, my invention difi'ers from the above nethods in striking at the cause instead of the effect-that is to say, in. controlling the consistency instead of the flow, and in supplying the water to and redncing that portion of the material which governs the flow, instead of to a different portion which has already been tested.

lt is to be particularly noted that in the form of apparatus shown by me the quantity of material in the regulator remains unchanged, and that the change in densityand specific gravity regulates the action; that the flow and the consistency remain continuous and unchanged, and that the water is added directly to the stock being weighed or tested.

Having thus described the nature of my invention, and one form of the apparatus which may be enployed, what l claim is- 1. An apparatus for controlling the consistency of paper stock, consisting of a balanced vertically-moving receiver, arranged so that the pulp passes through the same, and a water-supply arranged to dischargc into the receiVer, and to be controlled in its rate of discharge by the movement of the receiver, substantially as shown.

2. The combination of the receiver A, balancing devices B C, with a stock-feedcr, F, and water-feeder E, both arranged to deliver into the receiver, and the latter arranged to be controlled by the vertical movement of the receiver.

3. In a feed-regulator for paper-machines, a balanced regulating-receiver, A, arranged to rise and fall past the mouth of a water-pipe, E, as and for the purpose described and shown.

4. In a ieed-regulator for paper-machines, a balanced regulatin g-receiver, A, provided with. a vertical partition, d, and a passage thereunder, said receiver being arranged to receive the stock on one side of the partition, cause its passage thereunder, and then discharge it upon the opposite side, as described and shown, whereby the stock is delivered of a uniform consistency.

5. The herei'-described method of securin g a uniforn consistency of the stock or stuff while being fed to paper-machines, cosisting in the employment of a fixed Volume of stock or stuff, in connection with a counter-balance, and causing Variations in the specific gravity of said pulp to control the addition ot' water thereto, in the manner and by means substantially such as described and shown.

6. In a feed-regulating device for papermachines,the combination of a balanced Vertically-moving vessel of fixed capacity and a water-supply controlled by the movements of the balanced vessel, substantially as described and shown.

7. The herein-described method of controlling the consistency of the stock in its passage to paper-machines, consisting in applying the specific gravity of each part or portion of the stock to control the addition of water to that particular part or portion, in the manner and by means substantially such as described and shown.

JOHN T. F. MAC DONNELL.

W'itnesses:

J. P. BUCKLAND,

EMMA L. JORDAN.

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