Installations for processing a product in a gas medium

Claim 1

An installation for processing a product in a gas medium, particularly a drying or heat treatment installation, said installation comprising: means defining at least one blowing chamber in which the product moves horizontally, treatment gas supplying means for supplying the blowing chamber with treatment gas, means defining a recovery chamber having two horizontal walls and disposed so as to surround the blowing chamber and the supplying means, means defining a plurality of discharge passages each having an inlet to said blowing chamber and an outlet to said recovery chamber so that a partial recycling of the treatment gas is provided from said discharge passages to said supplying means, intake means for admitting treatment gas into said recovery chamber, and discharge means for discharging a part of the treatment gas from said recovery chamber, at least one of the two horizontal walls of the recovery chamber comprising: means defining a plurality of flattened outer ducts forming said intake means and being oriented perpendicularly to the direction of movement the product, each of said outer ducts having an outlet in communication with the supply means, and means defining a plurality of flattened inner ducts forming said discharge means and being oriented perpendicularly to the direction of movement of the product, each of said inner ducts having an inlet situated between the outlets of the outer ducts and the outlets of discharge passages, said means defining said inner and outer ducts including a common dividing wall, provided between each outer duct and inner duct, for promoting heat exchange between the intake treatment gas and the discharge treatment gas, the intake treatment gas and the discharge treatment gas flowing in countercurrent relation in the outer and inner ducts, and the outer ducts being supplied in parallel with the intake gas, and the inner ducts being supplied in parallel with the discharge gas.