Claims
- 1. A method for the mechanical removal of moisture from of a filter cake formed on a filtering surface, wherein a treatment fluid flows through the filter cake as a result of an applied pressure-difference, comprising the steps of:
(a) presenting the filter cake in a liquid saturated state; (b) exposing and condensing a liquid phase of the treatment fluid an instant prior to the onset of crack formation; (c) adjusting pressure and temperature of the treatment fluid so that the treatment fluid initially condenses in a top layer of the filter cake furthest away from the filtering surface, wherein a condensation front forms along the top layer; and (d) progressively heating the filter cake up to a gas temperature of the treatment fluid from the top layer towards the filtering surface, wherein the condensation front at an interphase between the treatment fluid in a gas phase and the liquid phase is displaced towards the filtering surface.
- 2. The method of claim 1 wherein the gas phase of the treatment fluid is a pressure medium which generates a differential pressure bringing about the pressure difference.
- 3. The method of claim 1 wherein the treatment fluid permeates through the filter cake in stages.
- 4. The method of claim 3 further comprising the steps of:
(e) cooling the filter cake after the condensation front has penetrated into the filter cake; and (f) repeating steps (c) and (d).
- 5. The method of claim 1 wherein formation of the filter cake takes place using the treatment fluid as a pressure medium.
- 6. The method of claim 1 wherein the treatment fluid and a condensate produced therefrom having a low ionic strength, a low ion concentration, a mild, essentially neutral pH value is used, exhibiting a wash-out and extraction character for substances being extracted from the filter cake.
- 7. An apparatus for removal of moisture from of a filter cake formed on a filtering surface, wherein a treatment fluid flows through the filter cake as a result of an applied pressure-difference, the filtering surface arranged in a housing, in which the filtering surface is surrounded by a pressure-tight housing in the form of a pressure-chamber and the pressure-chamber is filled with a gas at a pressure above atmospheric, wherein the improvement comprises:
a hood covering at least a section of the filtering surface which, together with the filtering surface, encloses a second pressure-chamber containing the treatment fluid at a gaseous state.
- 8. The apparatus of claim 7 wherein the pressure in the first pressure-chamber and in the second pressure-chamber are essentially the same.
Priority Claims (1)
Number |
Date |
Country |
Kind |
P 42 38 087.1 |
Nov 1992 |
DE |
|
RELATION TO OTHER APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 08/432,169, filed May 10, 1995 and claiming priority to PCT Application PCT/EP93/03148 filed Nov. 10, 1993 and to German Application No. P42 38 087.1 filed Nov. 11, 1992.
Continuations (2)
|
Number |
Date |
Country |
Parent |
08631967 |
Apr 1996 |
US |
Child |
08815185 |
Mar 1997 |
US |
Parent |
08432169 |
May 1995 |
US |
Child |
08631967 |
Apr 1996 |
US |