Process and means for the heat treatment of powdery or granulate material

• US 4,876,802 A
• Filed: 06/23/1986
• Issued: 10/31/1989
• Est. Priority Date: 12/21/1983
• Status: Expired due to Term

• Current Assignee: Gerhard Gergely, Irmgard Gergely, Thomas Gergely
• Original Assignee: Gerhard Gergely, Irmgard Gergely, Thomas Gergely
• Inventors: Gergely, Thomas, Gergely, Irmgard, Gergely, Gerhard
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US06/877,112
• Time in Patent Office: 1,226 Days
• Field of Search: 34/15, 34/22, 34/33, 34/73, 34/92, 34/57 R, 34/57 E, 34/179, 34/181, 34/168
• US Class Current: 34/408
• CPC Class Codes: A61K 9/0007 Effervescent A61K9/0065 takes precedence
• CPC Class Codes: B01J 2/10 in stationary drums or troughs, provided with kneading or mixing appliances
• CPC Class Codes: B01J 2/16 by suspending the powder material in a gas, e.g. in fluidised beds or as a falling curtain
• CPC Class Codes: F26B 11/16 the stirring device moving in a vertical or steeply-inclined plane
• CPC Class Codes: F26B 5/04 by evaporation or sublimation of moisture under reduced pressure, e.g. in a vacuum F26B11/049 and F26B17/128 take precedence
• CPC Class Codes: F26B 7/00 Drying solid materials or objects by processes using a combination of processes not covered by a single one of groups F26B3/00 and F26B5/00 F26B1/005, F26B5/04, F26B23/026 take precedence

Abstract

Solid, loose particulate materials are treated with vaporizable agent in a process chamber. The materials are combined with a mixture of hot gas and vapor in order to condense finely subdivided amounts of the treatment agent on the material. After a suitable time of reaction, the condensed material is partially removed from the treated material so that the pressure in the process chamber is reduced at least to the point at which the treatment agent partially evaporates, whereupon the portion which has revaporized is extracted from the process chamber. This cycle of introduction and removal of the treating agent is preferably repeated in a program-controlled operation until the desired result is achieved and a product which is suitably agglomerated is obtained. In the present process, particulate material in powder or granule form is agitated and heat-treated in a closed drum, by stirring agents and surface treated by a hot gas flow forced over or through the charge of the material and then extracted intermittently by a vacuum pump. The air is heated and vaporized so that the vapor does not condense on the charge material.

Claims

1. In a process for heat treating agitated powder or granulate material contained in a closed drum wherein hot gas is driven through the material, the improvement which comprises the gas comprising a treatment agent and a carrier gas at a temperature sufficient that the treatment agent is present in the vapor state and is drawn through the agitated material, said material being at a temperature below the boiling temperature of the treatment agent and at nearly pressure, and after the desired reaction time, the treatment agent condensed on the material is evaporated and drawn out of the drum by the application of a vacuum at or below the pressure corresponding the boiling point of the treatment agent.

2. The process of claim 1, for the partial dehydration of material containing water of crystallization, wherein the treatment agent is an alcohol.

3. The process of claim 1, wherein at least during a part of the process a vacuum of about 600 to about 900 mbar, prevails in the drum.

4. The process of claim 1, wherein the gas flow is directed through the material being treated via at least one pipe to impinge finely distributed on a large number of points of the material.

5. The process of claim 4, wherein at least during a part of the process a vacuum of about 600 to about 900 mbar, is maintained in the drum.

6. The process of claim 4, for the partial dehydration of a material and containing water of crystallization, wherein the treatment agent is an alcohol.

7. A process for the treatment of material in a closed drum, wherein intermittently, until a predetermine result is achieved

(i) a hot gas flow is passed over or through a charge of solid, granulate material, and

(ii) wherein hot air in the drum is extracted by vacuum, characterized in that the hot gas flow before entering the drum is under pressure and contains vaporous treatment agent, and wherein the drum wall is heated and wherein the hot gas supply is interrupted during at least a part of the extraction phase.

8. The process of claim 7, wherein the hot gas is of such a temperature and contains a vapor content so that the vapor does not condense on the material.

9. The process of claim 8, wherein measured at a time during the extraction, the pressure difference between the entry and the exit of the hot gas is not greater than 0.4 bar.

10. The process of claim 7, wherein the pressure differential between the entry and the exit of the hot gas is a minimum of 600 mbar.

11. The process of claim 7, wherein the material is agitated every 60 to 300 seconds.

12. The process of claim 7 for the manufacture of a product containing at least one toxicologically acceptable, water-soluble acid in a relatively coarse-grained form as well as at least one relatively fine-grained reactant wherein the water is used as treatment agent and is introduced in a quantity which is just sufficient to bind the reactant to the surface of the coarse-grained acid.

13. The process of claim 12, wherein the fine-grained reactant is calcium carbonate, and wherein about 1 to 5 volumetric parts of hot air are laden with one volumetric part of water vapor.

14. The process of claim 13 wherein 2 to 4 volumetric parts of hot air are laden with one volumetric part of water vapor.

15. Process as claimed in claim 12, wherein at least one first member of the group consisting of oxides, hydroxides and salts, a second member of the group consisting of alkaline carbonates of hydrocarbonates are fine-grained reactants.

16. A process for heat treating an agitated powder or granulate material comprising passing a hot gas having entrained therein a vaporized treatment agent, the boiling point of the treatment agent being between 0°

and 200°

C. and the temperature of the hot gas being at least 10°

greater than said boiling point and the concentration of said agent being from 0.1 to 55 volume %, through a vacuum vessel containing said powder or granulate at a temperature below the boiling point of said treatment agent, with the prevailing vacuum and temperature conditions being such that at least a part of the treatment agent condenses, thereafter adjusting said prevailing conditions such that at least a part of the condensed treatment agent vaporizes, and removing the vessel vaporized treatment agent from the vessel.

17. The process of claim 16 wherein said sequence of condensation and vaporization is repeated at least once.

18. The process of claim 17 wherein said treatment agent has a boiling point from room temperature to 100°

C., said hot gas has a temperature from 110°

to 150°

C. which is at least 20°

greater than said boiling point, and the vacuum in said vessel during the condensation treatment is 200 to 400 mbar and is 10 to 30 mbar during the vaporization.