Abstract Fine-grained material, such as lime, dolomite and magnesite, is subjected to a thermic treatment in suspension in a hot gas stream and the desired product is subsequently separated in a separator. A vertically disposed treatment chamber is divided into two vertical parallel reaction zones and is connected at its lower end with a hot gas producer whose hot gases pass through the treatment zones and into separator. The material to be treated is so introduced into the treatment chamber that the coarser fraction of the material drops in one of the reaction zones into an upstream of the hot gas having a relatively low velocity while subsequently in the other reaction zone the material is caused to flow with increased velocity and then into the separator. The exhaust gas leaving the separator is conducted to a preheater, preferably a multistage cyclone heat exchanger, and the dust discharge conduit of the latter is connected with one of the two reaction zones of the treatment zone. The treated material which leaves the separator is cooled and the extracted heat is conducted to the hot gas producer as additional combustion air.
The method according to claim 1, including the steps of controllably diverting a portion of said treatment gas from said preheater, and passing said diverted portion to the hot gas producer.
Claim 2
Dependent Claim
53 words
The method according to claim 1, including the steps of passing a portion of the treatment gas leaving said preheater to a dust separator, and returning the separated dust from said dust separator to said preheater thereby causing said separated dust to enter into a mixture with saId material introduced into said preheater.
Claim 3
Independent Claim
144 words
A device for thermally treating fine-grained materials, such as lime, dolomite and magnesite, while in suspension in a hot treatment gas stream, including means forming a longitudinal vertically disposed treatment chamber, a hot gas producer connected to the lower end of said treatment chamber, a separator connected to the upper end of said treatment chamber, a preheating device for the material to be treated connected to said separator, means for conducting material to be treated from said preheating device to said treatment chamber, a cooling device for the treated material connected to the separator, a conduit which is divided at the outlet of the preheating device, one branch of said conduit for the treatment gas including a regulating valve and being connected with a dust separator while another branch of said conduit includes another regulating valve and is connected to said hot gas producer.
Claim 4
Independent Claim
139 words
A device for thermally treating fine-grained materials, such as lime, dolomite and magnesite, while in suspension in a hot treatment gas stream, including means forming a longitudinal vertically disposed treatment chamber, a hot gas producer connected to the lower end of said treatment chamber, a separator connected to the upper end of said treatment chamber, a preheating device for the material to be treated connected to said separator, means for conducting material to be treated from said preheating device to said treatment chamber, a cooling device for the treated material connected to the separator, a conduit connected to the outlet of the cooling device, said conduit which discharges the heated cooling air being so divided that one branch leads to the exhaust gas conduit of the preheating device while the other branch is connected to the hot gas producer.