The invention discloses method and system of drying renewable sources of energy and raw material. The drying process is carried out under partial vacuum conditions and at lower temperatures than conventional dryers. The temperature to dry the material and the rate of water removal are controlled by regulating the degree of vacuum and the intensity of heat input. A method for drying material to moisture content below 10% by weight, comprises introducing into an ejector a stream with a pressure above ambient pressure, creating partial vacuum in a drying chamber through the secondary nozzle of the ejector when the stream enters the ejector and provides the motive pressure to the primary nozzle of the ejector, said drying chamber having an inlet into which a wet material is introduced and an outlet for taking out the dried material after the drying treatment, drying the wet material using low temperature waste heat.

The invention discloses method and system of drying renewable sources of energy and raw material. The drying process is carried out under partial vacuum conditions and at lower temperatures than conventional dryers. The temperature to dry the material and the rate of water removal are controlled by regulating the degree of vacuum and the intensity of heat input. A method for drying material to moisture content below 10% by weight, comprises introducing into an ejector a stream with a pressure above ambient pressure, creating partial vacuum in a drying chamber through the secondary nozzle of the ejector when the stream enters the ejector and provides the motive pressure to the primary nozzle of the ejector, said drying chamber having an inlet into which a wet material is introduced and an outlet for taking out the dried material after the drying treatment, drying the wet material using low temperature waste heat.

Method for harvesting and processing water hyacinths, characterized in that the following steps are performed: a) the water hyacinths growing in an aquatic medium are cut; b) the water hyacinths are collected on board a barge at berth (1); c) the collected water hyacinths are transferred onto draining racks (2) near the quayside; d) the drained hyacinths are washed with clean water; e) the washed water hyacinths are drained on vibrating belts (7) in order to remove some of the excess water; f) the water hyacinths are dried on a dryer (8) at a temperature of between 50 and 100 C. for 5 to 17 h; g) the water hyacinths and their seeds are steam-sterilised at a temperature of between 80 and 100 C. in order to sterilise them; h) the sterilised water hyacinths and seeds are ground in order to make profitable use thereof.

A method for drying biomass fuel using waste heat of flue gas from a power plant. The method includes: 1) stepwise recovering, by multi-stage condensation, sensible heat of flue gas; stepwise heating air using the sensible heat, to yield first-stage dry air and second-stage dry air; 2) convectively drying and dehydrating biomass fuel using the first-stage dry air having a temperature of between 150 and 180 C.; 3) further convectively drying and dehydrating the biomass fuel using the second-stage dry air having a temperature of between 80 and 100 C.; and 4) drying and dehydrating the biomass fuel using the third-stage dry air having a temperature of less than or equal to 25 C.

A method for drying biomass fuel using waste heat of flue gas from a power plant. The method includes: 1) stepwise recovering, by multi-stage condensation, sensible heat of flue gas; stepwise heating air using the sensible heat, to yield first-stage dry air and second-stage dry air; 2) convectively drying and dehydrating biomass fuel using the first-stage dry air having a temperature of between 150 and 180 C.; 3) further convectively drying and dehydrating the biomass fuel using the second-stage dry air having a temperature of between 80 and 100 C.; and 4) drying and dehydrating the biomass fuel using the third-stage dry air having a temperature of less than or equal to 25 C.

A drying machine for pasty and/or granular substances, which comprises a supporting frame for a plurality of superimposed conveyor belts, the frame being provided with lateral openings for the passage of air, each conveyor belt being supported by a plurality of spaced rollers which are pivoted to the frame, the rollers being surrounded by spacers which are adapted to define, between the rollers and the belt, air passage spaces to optimize the drying of the conveyed substances, each roller being surrounded by a single helical body with spaced turns that define the air passage space between the roller and the belt.

A drying machine for pasty and/or granular substances, which comprises a supporting frame for a plurality of superimposed conveyor belts, the frame being provided with lateral openings for the passage of air, each conveyor belt being supported by a plurality of spaced rollers which are pivoted to the frame, the rollers being surrounded by spacers which are adapted to define, between the rollers and the belt, air passage spaces to optimize the drying of the conveyed substances, each roller being surrounded by a single helical body with spaced turns that define the air passage space between the roller and the belt.

There is provided a multi-module counterflow drying apparatus (100) for drying material, the apparatus (100) comprising: a material inlet (102); a material outlet (104); a heat inlet (108) for inputting heat to the apparatus such that the heat traverses the apparatus in the opposite direction than the material; and a plurality of mutually interchangeable modules (110) stacked on top of each other, wherein the material is configured to move in the apparatus from one module to another such that the movement direction of the material in a given module is opposite to the movement direction of the material in a module above or below, wherein each module (110) comprises: movable paddles (210) configured to discontinuously move the material forward in the module (110).

There is provided a multi-module counterflow drying apparatus (100) for drying material, the apparatus (100) comprising: a material inlet (102); a material outlet (104); a heat inlet (108) for inputting heat to the apparatus such that the heat traverses the apparatus in the opposite direction than the material; and a plurality of mutually interchangeable modules (110) stacked on top of each other, wherein the material is configured to move in the apparatus from one module to another such that the movement direction of the material in a given module is opposite to the movement direction of the material in a module above or below, wherein each module (110) comprises: movable paddles (210) configured to discontinuously move the material forward in the module (110).

A multiple product belt drier having a first air permeable conveyor belt on which the materials to be dried are poured to form a first drying path; at least a second air permeable conveyor belt to assure at least a second drying path for drying the materials after the first one; an air blowing mechanism; an air heating mechanism for heating the blown air to dry the materials, and a drying air distribution circuit for distributing the drying air towards the materials and the belts; the drying air circuit being provided so that the drying air circulates downwards through the materials to be dried and the belts, and an air reheating mechanism is provided between the two paths to reheat the air which has passed through the layer of materials on the first belt, before it passes through the layer of materials on the second belt.