Method and device for producing an expanded granulate
US10611686B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 2016 |
| Grant date | Apr 7, 2020 |
| Priority date | — |
| Expiry date | Jul 25, 2036 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF27D2099/0086
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
The invention relates to a method for producing an expanded granulate (29) made of a sand grain-shaped mineral material (1) using a propellant; wherein the material (1) is fed to a substantially upright furnace (2); wherein the material (1) is conveyed along a conveying path (4) through a plurality of vertically separated healing zones (5) in a furnace shaft (3) of the furnace (2), wherein each heating zone (5) can be heated by at least one independently controllable heating element (6); wherein the material (1) is heated to a critical temperature at which the surfaces (7) of the sand grains (1) become plastic and the sand grains (1) are expanded through the propellant. It is provided according to the invention that the material (1) is fed together with an amount of air from below, wherein the material (1) is conveyed from bottom to top along the conveying path (4) by means of the amount of air which flows from bottom to top within the furnace shaft (3) and forms an air flow (14), and wherein the expanding of the sand grains (1) occurs in the upper half, preferably in the uppermost third, of the conveying path (4).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.