|DRYERS AND COOLERS|
The supply of sand often contains moisture (unless dried sand is purchased) which is more than what may be used in foundry, especially for core making or for chemically bonded sand system. Therefore, the supplied sand needs to be dried to a known moisture content. Since during drying the sand becomes hot, the same often needs Coolers also so that it can used in the process without without delay.
Wesman supplies Sand Drying & Cooling plant complete with equipment for handling and storing of dried and cooled sand. These plants are available from capacities of 3 TPH to 50 TPH. Wesman also supplies individual Dryer and Cooler of smaller sizes – from 200 kg to 5 MT per hour.
Most users prefer Wesman's fuel efficient Fluidized Bed dryer / cooler, but if customer prefers we also make and supply Rotary Drum dryer / cooler. Wesman Indigenously developed High Efficiency Fludised Bed Dryer and Cooler in 1985 and have a large reference list of users.
When air or gas is passed through a bed of particulate solid material, at a particular range of velocity, the solid bed gets converted into Gas-Solid mixture, expands and the particles move within the bed. At this velocity range the dispersed solid particles acquire many of the properties of a fluid and is said to be in FLUIDISED state. In fluidized state intimate contact between hot gas and solids at high relative velocity enhances heat transfer rates. Thus higher efficiency is obtained due to fluidization. About 30 to 40 % fuel saving is possible in case of Fludised bed dryer compared to Rotary dryer.
Hot air / gas is supplied at a specific pressure in the pressure chamber from which it flows through the distribution plate to the container having the bed of sand to be dried. Hot air may be supplied from oil / gas fired Hot Air Generator (HAG) or an Electric Air Heater. The HAG / Air Heater have been specially designed to operate at relatively high back pressure.
The Wesman range of Fluidized Bed Sand Dryers can be configured for continuous or batch operation and are designed to operate at wide temperature ranges - from 1600C. to 6000C. In case of low temperature operation, the dried sand is discharged at a comparatively lower temperature. In case of high temperature operation, the yield is more but it will necessitate use of a larger after-cooler. Wesman supplies the matching after-cooler, which also works on the principle of fluidized bed where, instead of hot air, ambient air is used to fluidize the column of hot sand delivered from the drier.
Fluidized bed dryers of various sizes have been/may be supplied for drying Food grains, Coffee seeds, garnets, Garnet, Eliminate, Rutile and other substances.