DE2514129A1 - DEVICE FOR ACHIEVING A UNIFORM FLOW PROFILE - Google Patents

Description

BASF Aktiengesellschaft

Our sign O "Ζ. 31 24Q Bk / Wn 67ΟΟ Ludwigshafen, March 27, 1975

Device for achieving a uniform flow profile

The invention relates to a device for achieving a uniform flow profile of highly viscous liquids when flowing through tubes or reaction chambers using disks arranged transversely to the direction of flow with openings c

When liquids with high viscosity flow through tubes or reaction spaces, it is difficult to achieve a uniform flow Flow profile, i.e. to maintain a uniform flow velocity over the entire cross-section »Through the influence the wall, the flowability is so influenced that the

Part of the viscous liquid located in the middle leads = This has the consequence that the residence time of the individual liquid particles in the tube or reaction chamber is different and a large proportion of the liquid only leaves the tube or the reaction chamber after a longer time than the proportion of the liquid out of the middle zone ₀ This is particularly undesirable if a reaction is taking place in the liquid, the progress of which depends on the residence time. and low molecular weight fractions.

DT-PS 1 136 310 already discloses a device for achieving this a uniform flow profile known, with cylindrical stapled in a hexagonal arrangement to form disks Filling bodies are provided with wall cutouts protruding into the interior and the disks in the flow through Pipe or reaction spaces at intervals vertically

136/75 609840/0633 -2-

- 2 - OoZo 31 249

25H129 -

to the direction of flow are built in »The production of such However, washers is technically very complex, since the individual cylindrical filler bodies have to be produced first and then stapled a plurality of these packings together have to be ο In addition, the device has the disadvantage that once the size of the packing has been selected, a Modification is only possible by replacing all of the fillers, i.e. a completely new pane has to be built.

It has now been found that when highly viscous liquids flow through tubes or reaction chambers, a A uniform flow profile is achieved by using disks with openings arranged transversely to the direction of flow, when the disks are designed as annular bands of increasing diameter, which are spaced concentrically on a grate are arranged, the walls of the annular bands running parallel to the direction of flow.

The new device has the advantage over known devices that it can be produced in a simple manner from semi-finished products can be produced by packing. In addition, the dimensions, e.g. the distances at which the ring-shaped Bands are arranged to change much easier without having to make a completely new device must become.

Preferred highly viscous fluids are, for example melting polylactams obtained in the polycondensation of lactams having from 5 to 13 ring members, at temperatures of up to 250 ⁰ C l4o. The device is of particular technical importance in the production of polycaprolactam.

The annular bands advantageously have a width of 1.5 to 10 cm, in particular 3.5 to 8 cm. You will be on one Grate, e.g. a cross grate or a spider-like substructure, concentrically at intervals with increasing diameter arranged in a perforated disc. The distances are advantageously 1.75 to 5 cm. Usually are the distances between the individual annular bands

609840/0633

- 3 - O.Z. 31 249

25H129

same. However, it is also possible that the annular bands with increasing diameter are arranged at larger or smaller intervals in order to change the flow behavior of the To compensate for melt, e.g. caused by additional heating inside or outside. To advance the To prevent viscous liquid in the center of the disk, a displacer is advantageously arranged there, which is expedient has tapered ends.

The disks can be used individually, advantageously used one in each case two disks in which the bands are preferably arranged offset. The distances between the individual pairs of discs are generally 3.5 to 20 cm. It has proven useful in reaction rooms ever Apply 4 to 10 slices in length. In another advantageous arrangement, the disks are staggered only separated from each other by the substructure as spacers.

It goes without saying that the disks each extend over the entire cross section of the tubes or reaction spaces.

It has proven to be particularly advantageous if the annular Belts are provided with wall cutouts protruding in the direction of flow (as in known packing rings) As a rule, 40 to 125 wall cut-outs are made for 1 meter of tape. A good effect when flowing through the stark Viscous liquids can also be achieved if the wall sections, which are arranged perpendicular to the direction of flow, are three-dimensional twisted like a ploughshare. The cutouts can alternate from disc to disc and tape to tape be twisted like a ploughshare in the sense of a left-hand twist or a right-hand twist. A particularly advantageous arrangement it looks like that in a first disc the wall cut-outs point outwards and from band to band are twisted alternately to the left or right and in the case of the next pane the wall cut-outs are turned inwards are directed and also from band to band

6 09 840/0633 " ⁴ "

-K- ο ο ζ, 31 249

are twisted left or right «It has also proven useful that the wall cutouts are designed so that they act as spacers between the individual annular bands to serve.

Figure 1 shows the cross-section through a disc with a displacer 1, annular bands 2, wall cutouts 3 and the substructure 4, Figure 2 shows details from the top view and two disks A and B offset from one another, each with a displacer 1, annular bands 2 and wall cutouts 3 FIG. 3 shows the wall section from an annular band 2 with wall sections 3 twisted like a ploughshare and the substructure 4.

609840/0633

-5-

Claims (8)

- 5 - ο ο ζ. 31 249 25U129 Claims ( lj device for achieving a uniform flow profile of highly viscous liquids when flowing through tubes or reaction chambers using disks with openings arranged transversely to the direction of flow, characterized in that the disks are designed as annular bands with increasing diameter, which are spaced concentrically on a grate are arranged, the walls of the annular bands running parallel to the direction of flow. 2. Apparatus according to claim 1, characterized in that two or more discs are arranged offset from one another. 3. Device according to claims 1 and 2, characterized in that the annular bands are provided with wall cutouts which protrude perpendicular to the flow direction into the distances between the individual annular bands. 4. Device according to claims 1 to 3, characterized in that the wall sections are twisted three-dimensionally similar to ploughshare. 5. Device according to claims 1 to 4, characterized in that the wall sections of tape to tape and disc to disc are alternately connected in the sense of a left and a right twist ploughshare. 6- Device according to claims 1 to 5 *, characterized in that the wall sections are directed alternately inwards or outwards from pane to pane. 7. Device according to claim 6, characterized in that a truncated conical displacer is arranged in the center of the disc. 6098 L 0/0633 " ⁶ ~ - 6 - O.Z. 31 249 25H129 8. Device according to claims 1 to J _1, characterized in that the wall cutouts are designed as spacers between the individual annular bands BASF Aktiengesellschaft Sign. 609840/0633 Blank page