Device for performing chemical and/or physical reactions between a solid material and a gas

1. Device for performing chemical and/or physical reactions between a solid material and a gas, especially for preheating, cooling and/or calcining fine-grained materials, the device having at least three stages arranged one above the other, each stage comprising the following components:

a. a gas-solids suspension duct for conducting a gas-solids suspension,

b. means for separating the delivered solid material from the delivered gas,

c. a solids duct for discharging the separated solid material, and

d. a gas duct for discharging the separated gas,

the gas duct of one stage merging into the gas-solids suspension duct of the next-higher stage and the solids duct of one stage joining the gas-solids suspension duct of the next-lower stage,

characterised in that the junction of the solids duct and the gas-solids suspension duct of the third or a higher stage is provided below the highest point of the gas-solids suspension duct arranged two stages lower.

2. Device according to claim 1 , characterised in that the gas-solids suspension duct comprises an ascending and a descending duct portion.

3. Device according to claim 1 , characterised in that the gas-solids suspension duct is at least partially in the form of a helical and/or spiral duct.

4. Device according to claim 3 , characterised in that the helical and/or spiral ducts of consecutive stages have alternating left-handed and right-handed orientations.

5. Device according to claim 1 , characterised in that there are provided at least two parallel strings having at least three stages each.