US3128790A - Stock inlet - Google Patents

Description

April 14, 1964 Filed Dec. 5, 1960 3 Sheets-Sheet 1 1'1 III/ lab 0 l {1 I0 I I l- I INVENTOR.

VIVIAN 5 GEATE' R ATTOPNEY April 14, 1964 v. s. GRATER 3,128,790,

STOCK INLET Filed Dec. 5, 1960 3 Sheets-Sheet 2 INVENTOR. VIVIAN 5 GEATER 3 Sheets-Sheet 3 Li. .L. m m mwn nm IN VEN TOR.

.i flu d I lllmrlulllllLmklllxlhusll V. S. GRATER STOCK INLET April 14, 1964 Filed Dec. 5, 1960 United States Patent Ofifice 3,128,790 STOCK INLET Vivian S. Grater, Beaconsfield, Quebec, Canada, assignor to Dominion Engineering Works Limited Filed Dec. 5, 1960, Ser. No. 73,767 i Claim. (Cl. 137-605) This invention relates to new and useful improvements in connection with a paper machine headbox or stock inlet and has particular reference to new and improved means for modifying the flow characteristics of the incoming stock.

The principal object of the invention is to provide new and improved means for removing from the flow of stock, by the dissipation of energy into turbulence, unwanted and undesirable crosscurrents which produce uneven velocity profiles, arising in a paper machine headbox due to the physical limitations of converting a flow from a pipe into an even flow into a headboX the full width of a paper machine.

Another object is to provide new and improved means whereby irregularities in sheet formation may be corrected while the machine is in operation.

Another object of the invention is to provide a device of the type set forth wherein means is provided for modifying the flow characteristics of the incoming stock which consists of providing adjustable throttling means in the entrance passage to the headbox to thereby modify the flow characteristics of the incoming stock.

Another object of the invention is to provide new and improved means of the type set forth which are adjustable and the adjustment of which may be carried out while the machine is in operation.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the acompanying drawings. It will be understood that changes may be made in the details of construction and arrangement of parts without departing from the scope of the invention as set forth in the accompanying claim.

Referring to the drawings:

FIGURE 1 is a sectional view of a pressure stock inlet embodying the invention;

FIGURE 2 is a fragmentary sectional view of the device shown in FIGURE 1 but on an enlarged scale;

FIGURE 3, is a fragmentary sectional view generally similar to FIGURE 2 but taken on an enlarged scale;

FIGURE 4 is a sectional view taken on line 4-4 looking in the direction of the arrows; and

FIGURE 5 is a fragmentary sectional view generally similar to FIGURE 4 but on an enlarged scale.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout, the device shown embodying the invention inc eludes the distributor which is preferably of the crossflow type such as disclosed in U.S. Patent No, 2,869,436 of January 20, 1959, to A. E. Stewart, or other suitable type of distributor is adapted to provide stock to the he adbox designated generally as 11 from which it is adapted to pass through the outlet 12 to the breast roll 13.

The distributor 10 comprises a pair of distributor members 10a and 10b each adapted to supply stock to the headbox 11 through the convergent ducts 14 and 15 respectively to the common duct 16 through which stock passes to the interior of the headbox 11.

At the point where the two streams from the distribu turbulence, unwanted and undesirable cross currents which produce uneven velocity profiles in the headbox in the conversion of the flow from the distributors into an even flow into the headbox the full width of the paper machine.

The unit for accomplishing this purpose comprises the oppositely disposed adjustable plates 1 which are shown in the extended position to illustrate the adjustment. These plates are made of suitable material such as stainless steel.

The control plates 1 are each slidably mounted in a holder 2 and are operatively connected to and adapted to be actuated by a plurality of screwed rods 3 and captive handwheels 4. The screwed rods are spaced along the length of the control plates 1 in order to give full and regular control over the position of the plates 1.

As will be seen from the drawings, the plates 1 are substantially normal to the direction of flow of the stock and are in aligned opposed relation.

In order that the control plates 1 remain free and clean, a water connection 5 is in communication by drilled ports 6 to a groove 7 in the holder 2. Water, at a pressure in excess of that within the stock inlet, is introduced to this connection 5 so that a small quantity of water is passed through the spaces 7 between the holder and adjustable plate 1 thus washing the interfaces and keeping them free of foreign matter. A suitable seal such as O-ring 8 is provided around adjusting rod 3 to prevent leakage of water to the outside.

It is pointed out that the plates 1 are flexibly adjustable in the plane of adjustment due to the push-pull effect of the screwed rod 3 and that such adjustments may be carried out while the machine is in operation and which allows irregularities in sheet formation to be corrected, such as thin edges, which require increased flow of stock at the edges to compensate as shown in FIG. 5.

Also, the effects of the adjustment may be observed as they are being made, enabling consequent further adjustments to be made with a minimum of delay,

In operation the quantity of stock passing the control unit will vary with machine speed and consistency and therefore it may be assumed that the amount of restriction required in the convergence of the two flows will vary. With this invention adjustment may be made with the machine in operation, thus enabling the operator to observe the results of the adjustment made and ensure that the flow of stock onto the Fourdrinier wire is at its opti-v mum. The acceleration produced will induce high turf bulence and the absorption of the unwanted uncontrolled energy, thus ensuring an even flow of stock into the head.- p per- It will be seen that with the present invention the control may be adjusted while the machine is in operation and as the adjustment can be made on either side it en; sures that the stock from ach distributor is equally treated. Furthermore, the sharp Orifice produced by the plate will ensure maximum unwanted energy absorption,

Furthermore, the unit acts as a means of breaking up 11068 or a s of fi re which may hav rmed in the st ck prior to the stock inlet,

The operation of the device is believed apparent from the foregoing,

From the foregoing it will be seen that I have provided Patented Apr. 14, 1964 new and improved means of obtaining all of the objects and advantages of the invention.

I claim:

A stock inlet for paper machine headboxes comprising two sources of stock, a pair of convergent ducts each fed upwardly and exclusively from one of said two sources of stock and terminating in a common duct, two independently adjustable elongated control plates having opposed sharp-edged lips arranged transversely of said common duct, and in opposed alignment, said lips being substantially normal to said common duct and forming a constriction therein, said plates being adjustable along their length and having plural means of adjustment mounted thereon in an evenly spaced arrangement, whereby the adjustability of the plates may be controlled at various points along their lengths, thus controlling the thickness of the incoming stock.

References Cited in the file of this patent UNITED STATES PATENTS 992,027 MOIlOCk May 9, 1911 1,095,767 Adams May 5, 1914 10 2,052,992 Simpson Sept. 1, 1936 3,038,538 Logan June 12, 1962

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