VENTILEX Evaporative Cooling Drying
The concept behind Evaporative Cooling is to not dry the product to the specified end moisture, but to use just enough energy to dry to within 0.5 to 0.7% of the end moisture, and then use the heat already inside the aggregate, coupled with a slightly increased cooling air temperature, to evaporate off the remaining moisture to the target result.
By using this method, the aggregate is not heated up so far, and thus you can understand that it is easier to cool it back down for later packaging, in the cooling section of the Dryer/Cooler.
Since time in the drying section equates to energy spent and that means money, VENTILEX exactly controls the end temperature of the aggregate in the dryer section. Organic and inorganic materials each have a drying curve, and the points on the curve relate to a specific temperature and moisture content. In this way, VENTILEX monitors via ultra-fast-acting PT-100 thermocouples IN THE PRODUCT BED [cannot do this with a Rotary or high frequency vibrating dryers!] combined with the latest PLC instruments and a special algorithm that has taken VENTILEX 10 years to perfect. With this system, VENTILEX adjusts the amount of energy necessary and no more additional energy is used. We then recover latent heat from the dryer exhaust stream, and control the cooling air to a very specific temperature to "evaporative cool" the aggregate to the exact desired discharge moisture.
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The system with evaporative cooling has the following advantages:
· The sand is not completely dried in the dryer, so the drying capacity per ft2 is increased.
· The energy per ton dried of sand is lower then when completely dried.
· The temperature of the sand is not too high when entering the cooler. Also the evaporation of water takes the heat out of the sand. This means that the sand is colder after cooling than when it is completely dry before cooling, so the cooling capacity per ft2 is increased.
With VENTILEX Evaporative Cooling and Recirculation of the air, the savings is normally 45% to 60% over a rotary drum dryer, and at least 27% and many times 45% lower than all other typical fluid bed dryers.
These savings are only possible because of the principals deployed combined with the advanced PLC control and programming, combined with high quality, ultra-fast instrumentation. All other fluid bed dryer companies for aggregates seem to use only cascading temperature controllers. These other fluid bed dryers control exactly opposite of the VENTILEX design. They control on the HIGHER of the control situation, and not on the lowest!
Ask VENTILEX to explain the controls and programming in detail. Once you see how we do it, you will completely understand how the energy is saved, and how we use the absolute least amount of fuel possible to obtain the desired end moisture.
Standard Drying | Recirculation Drying | Evaporative Cooling |Ventura 130
