Indirect heat dryer
Indirect heat transfer dryer "AKINDRY"
ATHANASIOS KOUTSOUKOS S.A. offers the indirect drier “AKDRY” for the dehydration of watery wastes and the final production of sludge with an extremely low content of water (content of water 10%). The content of water which is enclosed in the sludge vaporizes by the heat transferred through a metal surface (a jacketed body trough). The thermal exchange system consists of a thermal fluid expansion tank, the immersion heating resistances and the fluid recirculation pump. The heating medium can be oil, steam or water.
An online blower system draws the moisture off the top of the internal dryer and out through a wet scrubber system (barometric condenser). After 4-6 hours of drying time (depending upon the material), the dried sludge is removed by opening a valve located underneath the unit for discharge into a container under the action of gravity force or conveyed via a rotary screw to a distant packaging system.
The product is conveyed via a rotary screw. Residence time is controlled by the rotor speed and ranges from several minutes to one hour. The drier can also operate with low temperature in a vacuum condition (optionally) and drying time can be lessened by programming a significant differential temperature. The product enters at one end and moves by screw rotation to the discharge point at the other end. For temperature homogeneity at the heating medium a recirculation pump is provided. Screw rotation speed, controls retention time and discharge temperature of the product. The tumbling action of the short pitch screw makes the heat exchange uniform and efficient.
The conveyor screw
The screw conveyor is the Archimedes type. The revolution is given by axial gear motor. The shaft is supported by two cushions in both ends and a transmission chain is used between the shaft gear motor and the screw. The screw type thickness-pitch- is selected according to the feeding sludge. Screw feeders are set up to be flood fed, so that regardless of the amount of material in a hopper, above the inlet, the output rate will remain constant. It is this trait that makes screw feeders a critical part of a system, as they set the rate of material flow for the rest of the equipment downstream. Depending on the product being conveyed and the inlet size, different types of flights are used in screw feeders. Some options include tapered flights, variable pitch flights and cone mounted flights.
Thermal fluid immersion heaters
Flanged immersion heaters are used for heating gases and liquids (such as water, oil, heat transfer fluid and corrosive solutions). Designed for use in tanks and pressurized vessels, they are easy to install and maintain to provide heat for many processes. The direct immersion method is energy efficient and easily monitored and controlled. Flanged immersion heaters consist of hairpin bent tubular elements welded or brazed into a Flange and provided with wiring boxes for electrical connections. Flange heaters are installed by bolting to a matching flange welded to the tank wall or nozzle.
The filling system
The filling system is a Big Bag type where feed can be performed via gravity, screw or belt. Weighing is achieved via a four load cell platform weigh scale. Typical capacity ranges from 250kg to 1500kg. Fully automated big bag filling equipment with pallet magazine, roller conveyors and automatic bag release is also available.
Barometric spray condenser
The exhaust fumes are treated in a direct contact barometric spray condenser which is relatively simple in operation and inexpensive. The direct contact condenser has several advantages over shell and tube condensers, for instance it offers a greater efficiency due to a greater available surface area for heat transfer produced by the water droplets.
Initially, cool water droplets of a specific diameter are sprayed into the steam of the exhaust fumes. The fumes are forced to cool due to the difference in the temperature between the water droplets and the air and the water which is enclosed in the exhaust fumes, condenses. The latent heat which is released during the condensation of the water enclosed in the exhaust fumes, can be utilized by a heat exchanger, thus, converting it to energy which can be used for other usages. The condensed water as well as the water droplets are collected and can be used as the spray.
Typical applications of “AKINDRY”- Indirect drying system
Blanching, Chilling, Cooking, Cooling, Crystallizing, Drying, Heating, Mixing, Evaporating, Desolventizing, Reacting