DE9413689U1 - Filter medium mixture - Google Patents

Description

RICHTER, WE^sTCJERilViA'rsiN *&:CEREAL!LET .'. ·· "*

EUROPEAN PATENT ATTORNEYS ■ PATENT ATTORNEYS

HAMBURG ■ BERLIN

DIPL.-ING. JOACHIM RICHTER DIPL.-ING. HANNES GERBAULET D1PL.-ING. FRANZ WERDERMANN

- I9S6

NEW WALL IO KURFÜRSTENDAMM

2&Ogr;354 HAMBURG IO719 BERLIN

@ (O4O) 34 OO 45/34 OO 56 W (O3O) S 82 74 TELEX 2163551 INTU D TELEFAX (O30) 8 82 32

FAX (040) 35 24 !5 IN OFFICE SHARING WITH

MAINITZ & PARTNER LAWYERS ■ NOTARIES

HAMBURG

YOUR FILE OUR FILE

C94368III1535 24.08.1994

Applicant: CCC Ltd.
Title: Filter media mixture

The invention relates to a filter medium mixture for cleaning liquid hydrocarbons.

Dry cleaners always produce large amounts of organic solvents, which have to be reprocessed or disposed of after being used as cleaning agents for textiles. Distillation for cleaning is widespread and also appropriate. When chlorinated hydrocarbons are used in dry cleaning to date, distillation sumps are produced during distillation, which, since they still contain chlorine compounds with an unknown structure, have to be disposed of as hazardous waste.

As an alternative to halogenated hydrocarbons, halogen-free hydrocarbons are also used in dry textile cleaning, as these appear to be more toxicologically and ecologically suitable than halogenated solvents. However, these non-halogenated hydrocarbons have the disadvantage that they are flammable, so that distillation on a larger scale would require relatively extensive safety precautions, which would make the effort required in the cleaning process disproportionately high. Attempts have therefore been made to purify the solvents by filtration. Filter media containing diatomaceous earth and various phylosilicates were used. The aim was to achieve a level of purity equivalent to that achieved by distillation. However, this objective could not be fully achieved, as the used solvent contains a variety of substances that need to be removed, and not all of these substances could be retained sufficiently by the filter media. The hydrocarbons could not be freed to the desired extent from odorous substances, possible dyes or chemicals used for textile finishing.

The invention is therefore based on the object of creating a filter medium mixture which enables the purification of liquid hydrocarbons by filtration, whereby the degree of purity of the treated solvent must correspond to that of a solvent treated by distillation.

This object is achieved by the features characterized in claim 1.

For this purpose, the invention provides for a filter medium mixture which contains the following components:

a) Activated carbon

b) Diatomaceous earth

c) Phyllosilicate

Only by mixing components a) - c) is a degree of purity of the processed solvent achieved that allows it to be reused for cleaning textiles.

Advantageously, this filter media mixture can also be used in any other areas for cleaning solvents.

The activated carbon is preferably used in granular form, with a particle size of 1 - 3 mm being most suitable in order to achieve sufficient porosity of the filter medium, with the flow rate being in optimal relation to the cleaning performance.

However, in certain areas of application, the use of activated carbon powder is also possible.

The diatomaceous earth to be used is preferably flux calcined and has an average particle size of 6 μgr; - 12 μgr;.

The preferred phyllosilicate is an acid-activated calcium bentonite, which is a mixture of two different qualities in a ratio of 1:1, whereby one quality has the following characteristics according to the sieve analysis :

Below 0.25 mm 10% max.

0.25 mm - 0.6 mm 85% + 5% over 0.6 mm 10% max.

The other quality consists of a mixture of calcium bentonites with a size of

150 µm (98% content according to DIN 40) 75 µm (88% content according to DIN 80) 60 µm (80% content according to DIN 100).

A mixture of 10-20 vol. %, preferably 15 vol. % activated carbon granulate, 50-90 vol. %, preferably 56.6 vol. % acid-activated calcium bentonite and 10-50 vol. %, preferably 28.3 vol. % diatomaceous earth has proven to be particularly advantageous for the purification of non-halogenated liquid hydrocarbons for use _{in dry} cleaning.

Claims (9)

Expectations: 1. Filter media mixture for the purification of liquid hydrocarbons, containing diatomaceous earth and phyllosilicates, characterized in that the filter medium mixture contains activated carbon. 2. Filter medium mixture according to claim 1, characterized in that the activated carbon is granular. 3. Filter medium mixture according to claim 2, characterized in that the grain size of the activated carbon is 1-3 mm, preferably 1.5 mm. 4. Filter medium mixture according to one of claims 1 to 3, characterized in that the phyllosilicate is a calcium bentonite in acid-activated form. 5. Filter medium mixture according to claim 4, characterized in that the acid-activated calcium bentonite has the following particle sizes: less than 0.25 mm 10 % max. 0.25 mm - 0.6 mm 85 % + 5 % over 0.6 mm 10 % max. 6. Filter medium mixture according to claim 4, characterized in that the acid-activated calcium bentonite has a mixture of the following particle sizes: 150 µm (98% content according to DIN 40) 75 µm (88% content according to DIN 80) 60 µm (80% content according to DIN 100). 7. Filter medium mixture according to claim 5, characterized in that the acid-activated calcium bentonites according to claims 5 and 6 are mixed together in a ratio of 1:1. 8. Filter medium mixture according to one of claims 1 to 7, characterized in that the diatomaceous earth is flux calcined and has a particle size between 6 μg and 12 μg. 9. Filter medium mixture according to one of claims 1 to 8, characterized in that that the activated carbon, the diatomaceous earth and the acid-activated calcium bentonite are mixed in a ratio of 1:1.9:3.8.