A ROTARY oven could be a Direct laid-off, Refractory Lined instrumentation for top temperature applications wherever it's necessary to vary the 'state' of the fabric in an exceedingly continuous method or in batch kind method. Since this method sometimes needs a protracted duration, the length to diameter magnitude relation is usually in far more than 10:1 in an exceedingly continuous oven. In most cases associate degree oil or gas jet fires directly into the discharge finish of the unit. the fabric is heated in 3 ways - by radiation from the burner flame, conductivity from the refractory lining and convection by contact with the recent gases. they're conjointly used for cookery a good style of ores.
PRINCIPLE
The oven could be a cylindrical vessel, inclined slightly to the horizontal, that is turned slowly regarding its axis. the fabric to be processed is fed into the higher finish of the cylinder. because the oven rotates, material bit by bit moves down towards the lower finish, and should endure a precise quantity of stirring and admixture. Hot gases pass on the oven, typically within the same direction because the method material (co-current), however sometimes within the wrong way (counter-current). the recent gases could also be generated in associate degree external chamber, or could also be generated by a flame within the oven. Such a flame is projected from a burner-pipe. The fuel for this might be gas, oil or small-grained coal. Solids retention time within the oven is a vital issue and is about by correct choice of diameter, length, speed, slope and therefore the internal style.
CONSTRUCTION
The basic elements of a rotary oven area unit the refractory lined shell, support tyres and rollers, drive gear and burner system. A typical Rotary oven is cylindrical shell, slightly inclined from the horizontal and supported on 2 or additional tyres, that in rotate on rollers. one in every of the tyre is fastened by a collection of thrust rollers to require care of the thrust load throughout oven movement. The drum assembly in conjunction with tyres is revolved by a girth gear/pinion arrangement.
SEALING ARRANGEMENT
To maintain correct management of the degree and also the temperature of the gases flowing through the oven, it's necessary to limit the escape of the external cold air in to the oven wherever the rotating shell enter at the feed and discharge hood. Seal rings area unit provided at each ends between the hood and shell for this purpose. numerous styles of seal rings area unit used that embrace spring loaded rubbing kind wherever 2 finished metal surfaces area unit in grips below spring pressure and spring plate kind.
TYRES SUPPORT ROLLERS
Tyres, typically known as riding rings, typically comprises one annulate steel casting, machined to a sleek cylindrical surface, that attach loosely to the oven shell through wedge arrangements. These need some ingenuity of style, since the tyre should match the shell snugly, however additionally enable thermal movement. The tyre rides on pairs of steel support rollers, additionally machined to a sleek cylindrical surface and set concerning 0.5 a kiln-diameter apart. The rollers should support the oven and permit rotation that's as nearly resistance as doable. rely on size and capability an extra tyre will be given a group of support rollers. Kilns typically rotate at zero.5 to 2 rpm. The bearings of the support rollers should be capable of withstanding the big static and live masses concerned, and should be fastidiously protected against the warmth of the oven and also the ingress of mud. additionally to support rollers, there ar typically higher and lower "retaining (or thrust) rollers" bearing against the aspect of tyres, that stop the oven from slippy off the support rollers.
ROTARY COOLER may be a a part of Rotary kiln system accustomed lower the temperature of the new product discharged from the oven to a temperature approaching close. The Rotary Cooler is put in at a lower place the Rotary oven and interconnected with the oven discharge hood. the development is analogous to Rotary kiln with a cylindrical shell inclined to the horizontal with tyres, support rollers, feed hood and driven by girth gear & pinion. a vicinity of the cooler shell is castable lined to require care of the shell from the new discharge.
The Rotary Cooler operates in counter-flow, the new gases being substituted by close or chilled air, that is in direct contact with the new material. for top temperature applications the fabric is cooled to a temperature approaching close by continuous water spray over the shell and operates on the principle of warmth transfer through the rotating cylinder wall that is ceaselessly irrigated by a series of external water sprays mounted over the unit. The water is partly gaseous as steam whereas the surplus is collected from rock bottom of the unit and re-circulated. the fabric so cooled is discharged from the opposite finish of the shell.
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