DE1809104B2 - COLUMN FOR FRACTIONAL CRYSTALLIZATION IN TEMPERATURE GRADIENT AND PROCEDURE FOR OPERATING IT - Google Patents

Description

Crystal melt system).

The preferred dimension ratios of the Kri-25 Stallization columns are as follows:

The present invention relates to a column The ratio of the inside diameter of the column

For fractional crystallization at temperature, the length of which is approximately 1: 4 to 1:50, in particular

| radients se, ie a method of operating this particular 1:15 to 1:30.

Column. The ratio of the outside diameter of the rod

The transport of crystals and melt in 30 to the inside diameter of the column is in the

einer Kristallisationskolor.ne ir 1 countercurrent and of the order of about 1: 2, but can vary depending on

Tcmpcraturgradienten by means of a helix (screw size of the apparatus and the one to be separated

benfcdcr), which is strong in that due to the inner wall of the stoiisystemcn and temperature conditions

Column and one attached in the column axis vary.

(Fixed rod limited annular gap rotates in such a way that 35 The pitch of a turn is advantageously the same

that the turns are downward (i.e. against that of the difference between the inner ruuius of the column and

hotter part of the column) and which have the outer radius of the rod, but can also be the double

“Len entire annular gap is known to be pelle or half of this value. the

(FI. S ch i 1 d k η c ch t and H. Vetter, “The slope of the headwind is generally the same

wandte Chemie ”, 73, pp. 612 to 615 [1961]). At 4 ° as large as that of the turns.

iJiescm method can be large per unit of time. The speed of rotation of the helix is

Substances prevail, and it is continuously adapted to the respective circumstances and is before

lent representation of very pure substances possible, especially from the tenacity of the Krisiall-Scinnelze-

'even if mixed crystal system before system as well as from the dimensions of the helix

to bend. 45 (diameter, pitch) dependent. In most

There was now a column for fractionated cases, the speed of rotation is about 10 to

Crystallization found in the temperature gradient, 150 revolutions per minute. If the

which is much more efficient than the rod in front of the column axis rotates, is its

device described standing. The speed of rotation of the invention is usually 2 to 5 times higher than

proper column for fractional crystallization in the 50 is that of the coil.

Tcmpcraturgradien, in which in one through the Einführstclle for the raw material to be separated

the inner wall of the column and through one in the advantageously lies approximately in the middle of the column, the

Column axis lying rod limited annular gap removal points of the lower-melting substance (or

one that fills the entire annular gap and is separated from the material system) on the upper (i.e. coldest) column

The rod is arranged on a rotatable helix, is at the end.

characterized in that the rod to its longitudinal owing to the new counterwinding (s) on axis is rotatable and the coil at its lower lower end of the coil is the crystal pulp The end of one or more turn (s) opposite to the height of the turn change in the annular gap has a raised sense. lent condensed by adhering to the crystals

The method of operating the above-mentioned residual melt is pressed from the crystals. It

written column is characterized by the fact that a crystal

the rod about its longitudinal axis faster than the plug, consisting of the crystals of the higher-

Helix is rotated. melting product. To sell this product According to a preferred Ausfülirungsform will pull, the plug is partially due to the supply of heat.

the rod melted in the opposite direction to the direction of rotation of the helix 65, with part of this melt

turned. is withdrawn while the rest is back in the

The new crystallization column that passes over helix and countercurrent. It therefore goes without saying

the rod in the column axis can, depending on the temperature itself, that the tapping point on the column

i 04

3 4

tnipfehlenswerierweise run up at the level of the turn counter-turn and that

Change is appropriate. '"' '

The hottest point on the column is therefore on

s is appropriate. caprolactam promoted in these winding directions

will. The result on the turn change 6 bil

the height of the turn change. From there, the crystal plug is taken by means of a heating device 7

(Lie temperature, especially towards the top 5, partially melted and part of this melt

• jvj! the column steadily from. This temperature through the withdrawal point for the higher melting point

jjradientcn is generated in the usual way by subtracting fraction 8, while the rest of nejem

j-. Regular heating, cooling and warmth- passes into the countercurrent. The reference number 10 denotes

insulation. indicates the isolation.

It is also possible to have several columns of this type.

i'ii to switch cascade operation one after the other. melting and those for deep melting

The following examples as well as fraction 9, which dispenses with the drawing, have as much material! taken,

illustrate the invention. as introduced at the introductory part 1 crude product

Example 1 (see drawing) _i5 %; _{£ Column work} automatically without any con-

1500 g of melted raw caprolactam will roll or service would be required. The yield

Hour through the filler pipe 1 into the annular gap 2 of completely colorless pure caprolactam is 80 ¹ Vo,

pressed in. The column has a useful length "(ring - based on the crude product.

späh) of about 90 cm and an inside diameter _. ■, - ,, · ^ · ι "" \

8.2 cm. In the column axis there is “a fixed * o B e! s ρ ι e 1 2 (see drawing)

hollow rod 3 of 3.6 cm outer diameter eye- The helix 4 rotates at 20 revolutions per

brings. In the annular gap is a helix 4 with 28 minutes. The rod 3 rotates in the opposite direction

{lungs (only five of which are shown) and to the helix with 50 revolutions per minute, and

a counter turn 5 and a slope of 3.0 cm, the throughput of crude caprolactam is 5000 g / h.

brought. This helix is driven at a speed. The other conditions are the same as in

speed of 30 revolutions per minute. Example 1. The same applies to the yield of pure

cl rotates that the 28 turns down and the caprolactam.

1 sheet of drawings

Claims (3)

1 2 temperature ratios and the nature of the claims to be separated: crystal-melt systems, made of conventional materials. The focus here is on heat-resistant 1. Column for fractional crystallization VVerkätolTe, such as stainless steel, z. B. V2A (Werkstoliim Temperature gradients in which in a 5 No. 4541) or V4A (WerkstoiT No. 4571). through the inner wall of the column and through the surfaces of the annular gap (i.e. the co- a bar lying in the column axis and the inner wall of the column, by definition, hollow ring gap bordered by the entire ring gap or filled, rod) can be smooth or roughened be filled in, be provided with longitudinal or spiral grooves that can be rotated by the rod. in the Spiral is arranged, thereby kenn- io generally they are smooth. draws that the rod (3) around its longitudinal preferably rotates in the column axis axis is rotatable and the helix (4) on its lying rod during the entire transpon- uneven end of one or more turns around its longitudinal axis, advantageously in (5) has the opposite sense. Opposite direction to the turn of the helix. The staff can 2. The method for operating the column according to FIG. 15 can also be rotated back and forth alternately. By Claim 1, characterized in that this rotation of the rod gives you the possibility of Rod (3) about its longitudinal axis faster than the "harder to drive", i. H. a denser crystal pulp Helix i-)) is rotated to use as it is in an otherwise same 3. The method as claimed in claim 2, characterized in that the apparatus is possible with a fixed rod indicates that the stick would be in the opposite direction to 20, which in turn would be about 3 to 6 times larger Rotation of the helix is made. Throughput allowed per unit of time ("denser." Crystal pulp means a higher proportion of crystals in the