DE2331239A1 - FUEL TRAY FOR A PAPER MACHINE - Google Patents

Description

Headbox for a paper machine

The invention relates to a headbox for a Machine for making a paper web and a method for making part of this box.

In paper machines and related machines, which are used for the formation of paper and other webs, come Headboxes for use which extend across the width of the machine to carry a stream of in one Tube of raw material fed by a vane pump in a wide, flat, steady stream of controlled turbulence transfer, which moves at a substantially uniform speed, to on a moving Fourdrinier wire or to be deposited between a pair of such Fourdrinier wires.

Among the various forms of headboxes that have been developed to date, that is similar to that in U.S. Patent 3,298,905 described arrangement in terms of certain aspects of the present invention.

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In view of the great width of a paper machine, for which such stuffing boxes are used, proves It is important to ensure dimensional stability of the box in such a way that it is uniform throughout Flow behavior becomes possible for an acceptably wide range of head box operation.

It is therefore an object of the present invention to propose a headbox for paper machines, which extends to remarkable latitudes.

Another object of the present invention is based on create a controlled microturbulence in the outgoing raw material.

With the invention, a headbox is created which has a simple construction and is cost-saving Production is suitable «

With the invention, a scoff head box is also created, which provides satisfactory operation for a wide range of flow and which is capable of with a number of different raw material entries to work.

With the invention, a St off is also created on the crate, which is structurally complete and is suitable for the small available space in paper machines with double Longitudinal sieve is suitable.

With the invention, finally, a method is proposed brought to create a narrow access route, which great structural strength in a ieicr-cen structure has to have a pre-tuned at relatively low cost To achieve flow behavior.

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BAD ORKStNAL

Accordingly, a distributor area is provided in a headbox for a supply of a raw material suspension to a machine stowage device of a paper machine with a substantially uniform speed profile, which has an elongated, tapered pipe branch (header) which extends in a transverse direction to the machine to Receiving raw material from a raw material supply and a shallow mixing chamber ^M A "which extends transversely of the machine and is connected to the branch pipe by a plurality of substantially equally spaced flow connections, the flow connections in a surface adjacent to the mixing chamber open to the rear wall of the chamber in order to produce an impact of the raw material on the opposite chamber wall, which is at a distance "A ^w therefrom, before it is directed to an exit constriction of depth ^W E", wel surface is arranged at a distance "L" from the rear wall of the chamber,

where the ratio of length to height in the mixing chamber -r is equal to or greater than 6.

The invention also provides a headbox in which the ratio of the depth of the mixing chamber to the depth the constriction g is greater than 3.

A headbox is also provided in which the flow connectors comprise a plurality of connection tubes having an inner diameter "D" which are spaced apart from one another at center-to-center distances "C" along the branch, the diffusion ratio ^M N ⁿ of into the mixing chamber

AxC entering raw material flow by the expression i. is reproduced, where N has a value between 1.9 and 3 * 5.

Tests which have been conducted have shown that the present invention has certain advantages over headboxes a similar general arrangement can be achieved. These advantages are, on the one hand, the achievement of a uniform Flow distribution in the direction across the machine and the education

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development of stability for the flow both in the direction of flow and in the direction transverse to the machine. To this Another advantage is the achievement of uniform mixing, with the formation of flakes is avoided. Finally, one of the advantages achieved is that operation of the mixing chamber is sufficiently stable Way, so that it becomes possible to use pressure sensors for determining flow rates therein.

With reference to the accompanying drawings, the following describes certain embodiments of the present invention described. Show in it:

FIG. 1 shows a view of the rear of the machine to explain the flow pipe branch connection ;

Figure 2 shows a section of a headbox in connection with part of a paper machine using two longitudinal wires looking across the machine,

FIG. 3 shows a corresponding view of a further arrangement of the headbox in connection with a single longitudinal wire wet part; and

FIG. 4 shows a section along the line 4-4 of FIG.

In Figure 1, a headbox assembly 10 is shown which has a tapered branch pipe 12 extending in the transverse direction of the machine and a plurality of Has connecting tubes 14 which extend upwards, in the present case in the direction of the mixing chamber 16.

The mixing chamber 16 has a rear wall 18, a ceiling surface 20 and a floor surface arranged at a distance therefrom 22 on. Reference letters that relate to the relative proportions of the dimensions are shown in FIGS and 3 shown.

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The depth of the mixing chamber "A" across which the raw material flowing in from the connecting tubes 14 must flow has a relationship to the mixing chamber length "L" which is greater than or 6: 1.

The exit from the mixing chamber 16 is formed by a constriction 24 which has a depth "E ¹¹ which is less than 1/3 of the depth ¹¹ A" of the chamber. The converging part 26 of the ceiling surface 20 of the chamber, which delimits the constriction 24, runs inclined at an angle Θ, which is preferably between 35 and 55 degrees. A tilt angle of about 45 degrees was found to be particularly effective.

The flow path of the raw material diverges from the constriction 24 to a diffuser 30, which connects to a Access area 40 produces. The access area 40 has a constant depth P and a plurality of transversely extending Partition walls 42, which connect the top plate 44 <with the bottom plate 46 of the same in such a way that they have a Can transfer load. The diffusion in the feed area 40 occurs at a low rate, and the Diffusion angle is on the order of 7 degrees or less.

The access or transfer area 40 receives its stiffening by an underlying support structure 50. The Support structure 50 has a remarkable depth and depth great rigidity in the transverse direction to the machine.

The support structure 50 includes a base plate 62 with a Variety of standing plates 64, 66, 68. EJn front approach 69 carries a lower stowage plate 5 ^> while a rear extension 70 supports the inlet manifold 12. Adjustable front

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Support webs 72 and rear support webs 74 enable es, the inclination of the headbox according to requirements to vary.

The rigidity of the support structure 50 is transversely to the access or transfer area 40 by means of welded-on Plates 43 transferred, which part of the partition walls 42 as shown in FIG. In this way, this section will cover the entire area of the Workloads kept stable in terms of its dimensions.

As can be seen from the structure shown in FIG. 4, the access area 40 comprises a plurality of steel partition plates 43, which extend in the vertical direction between the ceiling and floor surfaces 44 and 46 of the access area extend to adjacent rows of rectangular-shaped To provide flow paths of great strength. The walls 48 of these flow paths are formed from molded epoxy, with appropriate streamlined fairings at their upstream and downstream ends, around an avoidance of sticking of raw material at the ends of the partition walls 42 the formation of a support even smooth flow. It is intended, that in addition to producing a rigid structure of a substantially unchanging cross-section the epoxy storage tubes 48 have a controlled degree of microturbulence due to the raw material flowing through them cause generated safer effect. The depth F of the access area 40 lies between the values A and E of the mixing chamber 16.

One of the structural side walls 39 is also shown in FIG. which is used to close the access area.

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The access area 4θ is provided with a superstructure which a flange plate 43 and end plates 45 and 47, which with the cover plate .44 provide a box-like structure in order to provide additional stiffening for the access area deliver.

During the production of the access area 40, the plact parts are of this structure assembled and welded together, including associated parts 64 and 66 of Support structure. Suitable casting cores, not shown in the drawing, are then spaced apart between placed adjacent one of the steel partition plates 43, whereupon a metal-filled epoxy resin is poured around these casting cores so that the flow channels of the access area 40 are completely be lined. The use of this manufacturing process makes it possible to produce a structure with a standard cross-section to be used with a control of the size of the passage channels according to the size of the casting cores used.

In the arrangements shown in Figures 2 and 3, the Length G (see Figure 3) of the flow channel chosen such that the turbulence added to the raw material by the manifold walls 42 of the access area 40 at least partially subside can before the lips of the stowage device are reached.

In an arrangement which included an access area 40 in which the access area had an interior height of 4.45 cm (1.75 inches), the length of channel G was approximately 63.5 cm (25 inches), giving the desired amount of decay the turbulence has been reached. In cases where an access area has been omitted, the dimension G can accordingly can be reduced in size.

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Returning to the embodiment shown in Figure 3, so it can be seen that this shows a headbox according to the invention, which in connection with a non-flooded Forming roll 80 is used which is suitable for making a multilayer plywood sheet. A corresponding The configuration can also be used in a tissue or cell tissue forming device, the embodiment shown, as can be seen, contains a multiple suction form roll.

The Sfcauvorrichtung 50 includes a top plate 52 and a bottom plate 54, said plates 52 and J- 5 ² are attached to the access area 40 to the inlet opening between them to keep constant for all flow operating conditions. The stowage device 50 includes external stiffeners 56 and 58 and an adjustable lip 60 to allow control of the stowage device opening by overall adjustment of the stowage device, as well as local control of the stowage device opening, as is well known in the related technology. The top wall of the stowage device can therefore be pivoted about the fastening point 53 by actuating actuating members 55.

The invention thus creates a headbox for a narrow profile which has a shallow mixing chamber with a length to height ratio equal to or greater than 6. The headbox has a series of tubes which connect the pipe branch with the expansion chamber, and a preferred diffusion ratio which is in a range between 1.9 and 3.5. A construction which a load that extends in the transverse direction of the machine is on one side as the rectifier section of the Headbox arranged with load transfer subdivisions extending across the depth of the rectifier section, in order to transmit a pressure load transversely thereto in such a way that the headbox is substantially undeformed during operation remains.

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Claims (1)

- Q _ Claims ij Headbox for a feed of a raw material suspension to a machine damming device of a machine for the production of a web-like material with a substantially uniform speed profile, in which a distributor area with an elongated, tapered drilling branch extends transversely to the machine direction in order to feed from a raw material feed in which a mixing chamber extends across the machine at a shallow depth * A "and is connected to the manifold by a plurality of substantially uniformly spaced flow connectors, the flow connectors on a surface of the mixing chamber adjacent the back wall of the chamber occur in order to cause an impact of the raw material against the opposite wall of the chamber, which is at a distance "A ¹ * therefrom, before it is forwarded to an exit constriction with a depth ^W S *, which is arranged at a distance "L" from the rear wall of the chamber, the ratio of Lft to height in the mixing chamber · | is equal to or greater than 6. 2. headbox according to claim 1, characterized in that that the ratio of the running of the mixing chamber to the depth the constriction j | greater than 3 iit 3 «headbox according to claim 2, characterized in that that the disturbance ever connection «β tiioke (14) contain a multiplicity of connecting tubes, which have an inner diameter * £ * 303884/0461 - ίο - have and are arranged at a center distance "C" along the pipe branch (12), and that the Diffusion ratio N of the one entering the mixing chamber AxC raw material flow is represented by the expression - . where N takes a value between 1.9 and 3j5. . ■ Stock box according to claim 1, 2 or ~ 5, characterized in that the constriction (24) which leads away from the mixing chamber (16) has an area (26) of the chamber surface which faces the other Surface of the chamber is inclined at an angle which is between 35 and 55 degrees. 5 · headbox according to claim 1, characterized by a Durahführungskanaleinrichtung (40), which in a die Flow rectifying relationship between the exit constriction (24) and an exit dam (6θ) arranged is, and a support structure means (50) for receiving a load which is external thereof is attached to substantially bending forces across the Machine direction to resist and around an adjacent wall (46) of the duct means during of the operation essentially undeformed, as well as characterized by a large number of load transfer subdivision devices (42), which are arranged transversely to the width of the headbox at a distance from one another and extend in the direction of the raw material flow, as well as the adjacent wall (46) on the channel wall (44) opposite to the same in a load transmitting relationship, so that the transmission channel means (4o) during operation under the action of hydraulic pressure forces of the raw material flowing through remain essentially undeformed. 309884/0461 - ii - 6. headbox according to claim 5, characterized by a Pair of lips (52, 5 * 0 * delimiting the stowage device, which is attached to the rectification device in a load transfer-permitting relationship, in order for the inlet flow area to the dam for all operating conditions of the box to be substantially constant to keep. 7. headbox according to claim 6, characterized in that that one of the storage device lips (52) is pivotally attached to the rectifying device, and that one first adjusting device (55) is provided to adjust the inclination of the lip of the stowage device relative to the other lip the same to control. . 8. headbox according to claim 7, characterized by a second storage device adjuster including a lip base portion (60) slidable on the storage device lip (52) and is slidable for locking. 9. A method for producing a rectifier area with a plurality of subdivision devices, which to transfer a load and to divide the flow between upper and lower inner surfaces (44,46) of the area to form a series of flow channels characterized by inserting a plurality of casting cores of a predetermined size and shape at a certain distance from the dividing device, as well as by pouring a filled curable resin (48) that bonds with the partition around flow channels to form, which have a predetermined cross section and a controlled flow resistance generating behavior. 309884/0461