Continuous drying of wet solids with high mechanical robustness, suitable for severe, uninterrupted duty. We design and manufacture the complete equipment: drum, flights, hot air generation, plenum and conveying.
A rotary dryer dries a wet solid and delivers a product with moisture below 10 %, depending on operating conditions. It is one of the most widely used methods for continuous drying and is suitable for a wide variety of materials, quickly and at low unit cost when medium and large quantities are involved.
The main body is a horizontal rotating hollow cylinder through which the product travels: it enters at one end and leaves at the opposite end. The cylinder can exceed 20 m in length and 3.5 m in diameter, depending on operating requirements and the flows processed.
It is a direct-type dryer, since the drying air comes into contact with the product. That air is normally heated in a direct hot air generator, where the drying air and the combustion gases are mixed.
The hot air can exceed 400 °C and is brought into contact with the wettest product to avoid burning it: the water it contains rapidly absorbs the energy and cools it almost instantly. The equipment can be single-pass or multi-pass, depending on how the hot air flows inside it.
Drying equipment in the plant.
The type of solid, its moisture and the flow rate define the diameter, the length and the flight system. If your product is not on the list, we can still evaluate it with a prior trial.
Granules and blends, with continuous operation and high homogeneity of the final product.
Biomass, milling by-products and pre-mixed pasty materials.
Mining concentrates and granular solids with large production flows.
Granular process solids that allow direct contact with hot air.
The points that define the design of a rotary dryer for each product.
The interior has product lifting flights which, besides increasing the heat transfer coefficient, ease the flow inside the equipment. As the dryer body rotates, the flights lift the product and let it fall like rain, which favours contact between air and particle.
The design of flights and scraper fins is defined according to the rheology of the material.
The product discharges into a plenum and is then conveyed by screws, both for discharge and for recycle. As in flash dryers, the equipment can have a recycle flow that allows the feed to be mixed with dry product and to enter the drying section with a suitable moisture for optimum performance.
This equipment can be designed for drying times of between 5 and 60 min, and capacities ranging from a few hundred kilograms per hour to more than 200 t/h.
The construction is designed for severe, uninterrupted duty, with adjustable drum inclination and a drive sized for continuous operation.
We test your product at our pilot plant and measure how it behaves before the final mechanical design. Less risk for your investment.
Our own metalworking capacity in Argentina, built to export standards. Spare parts and service without importing anything.
Equipment commissioned in Argentina, Brazil, Chile, Uruguay, Mexico, Colombia, El Salvador, Paraguay, Bolivia and Venezuela.
Technical backing from SEI Contreras, with engineers who speak your language and look after your plant.
Direct when the product can be in contact with the hot gases: it is more efficient and more economical. Indirect when the product cannot touch the combustion gases, because of contamination, colour or sanitary requirements.
The standard line reaches 5,000 kg/h and the technology scales considerably further. The higher the production, the more competitive the rotary dryer becomes against other technologies.
Yes. Materials and thicknesses are chosen according to the product and wear zones are reinforced. It is a decision taken at the start of the project.
WITech D&E designs and manufactures direct and indirect rotary dryers in Argentina, for fertilisers, mining, biomass and by-products, with more than 30 years of experience.
With the product, the capacity and the end use we will reply in less than 24 business hours, with a first technical assessment. If you wish, we can arrange a trial with your sample.
