The rotary dryer is a kind of industrial dryer employed to reduce or minimize the liquid moisture content of the material it is handling by bringing it into direct contact with a heated gas. A rotary dryer is said to be of the direct type if by virtue of its design, heat is added to or taken off the solids by direct exchange between the gas and solids. The direct heat dryer are the simplest and also the most economical class.
They are used whenever a direct connection with the hot gas or air is not really detrimental for the fed. When high temperature is needed for rotary evaporator in a direct-heated rotary dryer, a combustion chamber is used so when low temperature is necessary on the contrary, for thermolabile materials, steam coil is utilized. Rotary dryer can be said to be indirect once the heating medium is separated from exposure to the solid with a metal wall or tube.
Single Shell Rotary Drum Dryer – The dryer consists of a sizable, rotating cylindrical tube, usually backed up by concrete columns or steel beams. The dryer is inclined to slopes slightly in order that the discharge end is less than the material feed end to be able to convey the fabric with the dryer under gravity. Material to become dried enters the dryer, and because the dryer rotates, the content is lifted up by several internal fins lining the interior wall of the dryer. When the material gets high enough to roll back off the fins, it falls back down to the foot of the dryer, passing through the hot gas stream because it falls.
This gas stream may either be moving toward the discharge end through the feed end (called co-current flow), or toward the feed end through the discharge end (referred to as counter-current flow). The gas stream can be produced up of a mixture of air and combustion gases from the burner, in which case the dryer is called a direct heated dryer. Alternatively, the gas stream may include air or any other (sometimes inert) gas that is certainly preheated. When the gas stream is preheated by some means where burner combustion gases usually do not go into the dryer, the dryer referred to as an indirect-heated type. Often, indirect heated dryers are employed when product contamination is a concern. In some instances, a mixture of direct-indirect heated rotary dryers are also available to boost the overall efficiency.
A rotary dryer is suitable to dry metallic and nonmetallic mineral, clay in cement industrial and coal slime in coal mine, etc. Rotary dryers can be widely used to dry various materials, and therefore are very easy to operate.
Rotary Dryers have numerous applications but are most frequently seen in the mineral industry for drying sands, limestone, stones and soil, ores, fertilizers, wood chips, coal, iron sulphate, filter cakes, sewage sludge, etc. May also be applied to food industry mainly for liquids as well as for granular material including food grains, cereals, pulses,coffee beans, fermented tea leaves, etc.
Drum or shell variations: Double Shell Rotary Drum Dryer. Triple Shell Rotary Drum Dryer – A rotary dryer can consist of a single shell or many, though anymore than three drums is not usually necessary. Multiple drums is able to reduce the volume of space the equipment consumes. Multi-shell dryers include several concentric tubes. Multiple shells allow the dryer to be utilized in a more compact space. The drums are often heated directly by oil or gas burners. Incorporating a combustion chamber on the entry end helps ensure efficient fuel usage, and that homogenous drying air temperatures. Because the material moves through the rotating drum is heated and moisture released. Some dryers also offer the choice to cool, clean, shred, and/or separate the dried material.
For evaporating moisture from concentrates or other products from plant operations, Rotary Dryers are created and constructed for high efficiency and economy in fuel consumption. Whenever you can to apply heat direct to the material to be dried, Rotary Dryers in the Direct Heating Design are used. When it is unachievable to use heat direct towards the material to get dried, Rotary Dryers in the Indirect Heating Design may be furnished so that the heated gases will not are available in direct exposure to the content.
Rotary Dryer is an easy, inexpensive unit for reducing the moisture content of flotation concentrates, along with chemical and industrial products. Frequently the saving of shipping weight so effected will pay tjihbx the dryer in a few months. Difficulties from freezing whilst in transit can also be eliminated. Many industrial projects are actually using Dryers for control and production purposes on many materials.
Three main varieties of rotary evaporator could be supplied. The direct heat unit can be used after it is permissible for your drying gases to come in direct connection with the content being dried. Partition plates boost the heating surface. Drying might be by heat or exhaust gases using their company operations. If this drying gas has a deleterious effect on the product, then an indirect type of dryer can be supplied. Another derivation is the Tedrow Steam Dryer.
The movement of the material is due to combined effect of inclination in the shell for the horizontal and the internal tumbling action or mechanical turn over thus the name tumbling dryer. The nature of the feed determines the directions of gas flow through the cylinder which is relative to the solid. This drying equipment may also perform batch or continuous processing of the wet feed.