A belt dryer (belt drier) a kind of industrial dryer, is an apparatus which is used for continuous drying and cooling of woodchip, pellets, pastes, moulded compounds and panels using air,

inert gas An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. Though inert gases have a variety of applications, they are generally used to prevent u ...

, or flue gas.

Working principle

A Belt dryer / Belt cooler is a device designed for the particularly gentle

thermal treatment Thermal treatment is any list of solid waste treatment technologies, waste treatment technology that involves high temperatures in the processing of the waste Raw material, feedstock. Commonly this involves the combustion of waste materials. Sys ...

of product. The wet product is continuously and evenly applied through an infeed chamber onto a perforated belt. The belt, predominantly in horizontal position, carries the product through the drying area which is divided into several sections. In these cells drying gas flows through or over the wet product and dries it. Each cell can be equipped with a ventilating fan and a heat exchanger. This modular design allows the drying and cooling temperatures to be controlled separately in the different sections. Thus, each dryer cell can be individually controlled and the drying / cooling air flow can be varied in each cell. In addition, the speed of the

conveyor belt A conveyor belt is the carrying medium of a belt conveyor system (often shortened to a belt conveyor). A belt conveyor system consists of two or more pulleys (sometimes referred to as drums), with a closed loop of carrying medium—the conveyor b ...

can be varied what gives an additional parameter for setting of drying time. The cells can be heated or cooled directly or indirectly, and all heating media, such as oil, steam, hot water or hot gas can be used. Belt dryers are ideally suited to drying almost any non-flowing product and more granular products that require a lower throughput capacity.

Design features

Belt dryers / Belt coolers are designed in modular system. Each belt dryer consists of infeed hopper, conveyor belt and discharge end. Different kinds of dryers are possible to construct, e.g. * Single-belt dryer * Multi-stage dryer * Multi-level dryer * Multi-belt dryer ;Ventilation options In general there are two ways of gas flow pattern. The drying air can flow, according to the treatment process, either through or over the product.Thier, Bernd: Apparate: Technik – Bau – Anwendung. 2.Ausg. Essen: Vulkan – Verl., 1997 ;Heat Sources HEAT EXCHANGERS: * These are commonly used for application where a biomass heat source is available such as woodchip boilers to produce hot water or if there is a steam heat source available. OIL OR GAS FIRED BURNERS: * If a separate heat source is required a direct fired furnace with diesel, kerosene, LPG or natural gas burner can be used. Alternatively a heat exchanger with the same burner can be used for indirect heating if required. ;Exemplary conveyor options * Chain-guided wire mesh conveyor * Chain-guided hinge slat conveyor * Chain-guided steel plate conveyor * Chainless wire mesh conveyor ;Feeding variations * Granulating mill – filter cake or amorphous and paste-like products respectively * Slewing belt conveyor – sensitive and free flowing products * Distribution spiral * Rotatable arm feeding device – stable products * Plates feeding

Typical applications

Belt dryers are predominantly used in the following industries: *

Biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

* Pelleting *

Wood industry The wood industry or timber industry (sometimes lumber industry – when referring mainly to sawed boards) is the industry (economics), industry concerned with forestry, logging, timber trade, and the production of primary forest products and woo ...

Chemical industry The chemical industry comprises the companies and other organizations that develop and produce industrial, specialty and other chemicals. Central to the modern world economy, the chemical industry converts raw materials ( oil, natural gas, air, ...

* Anaerobic digestate *

Pharmaceutical industry The pharmaceutical industry is a medical industry that discovers, develops, produces, and markets pharmaceutical goods such as medications and medical devices. Medications are then administered to (or self-administered by) patients for curing ...

Food Food is any substance consumed by an organism for Nutrient, nutritional support. Food is usually of plant, animal, or Fungus, fungal origin and contains essential nutrients such as carbohydrates, fats, protein (nutrient), proteins, vitamins, ...

and feeding-stuff industry * Non-metallic minerals industry *

Plastics industry The plastics industry manufactures polymer materials—commonly called plastics—and offers services in plastics important to a range of industries, including packaging, building and construction, electronics, aerospace, manufacturing and transpo ...

* Ceramics industry

Sources and further reading

* Sattler, Klaus: Thermische Trennverfahren. 3. Aufl. Weinheim: Wiley-VCH, 2001 * Draxler, J.: Skriptum zur Vorlesung Thermische Verfahrenstechnik. Loeben: Mountain Universität, 2002 * Krischer, O.; Kast, W.:Trocknungstechnik – Die wissenschaftlichen Grundlagen der Trocknungstechnik. 3. Band. 3.Aufl. Berlin: Springer, 1992

References

External links

{{commons category, Belt dryers
Picture of belt dryer for sawdust

Picture of belt dryer for grass, forage maize and various biomass products

Double Sided Timing Belt

Máy sấy bùn thải
Dryers Belt drives Industrial machinery