In view of the above, pistachio shell and since one of the most energy-consuming processes in pistachio processing is the drying step, so to save energy in this process, sometimes with a slight change in the design of such systems can be Significantly reduces their energy consumption.
Effective steps that can be taken to reduce energy consumption in dryer systems include:
Choosing the right type of dryer: Choosing a dryer that has a higher thermal efficiency should be considered. The higher the thermal efficiency of the dryer, the more energy the fuel is used to dry the product and the less is wasted. For example, the table below shows the thermal efficiency of different drying methods for the corn crop (according to Table 3).
Choosing the optimal aeration speed: As previously described, high aeration speeds only increase energy consumption and have little effect on speeding up the drying process.
Use of appropriate temperatures: Low temperatures increase the drying time as well as energy consumption, while the use of high temperatures reduces the storage capacity of pistachio mani. Therefore, the appropriate temperature must be selected. In two-stage drying in which the moisture of pistachios is high at the beginning of the ballast process, it is possible to use higher temperatures. Of course, due to the variety of pistachio cultivars in the country, each of which has different physical and mechanical properties, a single method can not be proposed to dry all cultivars, but a common method in other countries is to use the two-stage method to first enter the pistachios They are dried and the humidity reaches 12% in 3 hours at a temperature of 82 ° C, then they continue the drying process at a temperature of about 50 ° C until the humidity reaches less than 5%.
- Use of accurate hygrometer and thermometer: As discussed, the purpose is to reduce the humidity and bring it to a certain value, and for this purpose, appropriate temperatures for drying pistachios are necessary, so the two parameters of temperature and humidity of the product must be carefully monitored. Be. Research shows that in wagon dryers, the highest fuel consumption is when the pistachio dries to a humidity of 4-6% (based on dry weight), and the lowest fuel consumption is related to the same dryer and when the pistachio is in it. Dry to 10-12% humidity. Therefore, it is better to monitor pistachios when the humidity level reaches 12% to bring pistachios to a safe moisture level in a way that consumes less energy, such as aeration.
- Using proper thermal insulation: Because a lot of heat loss has been observed around the furnace, it is better to use insulation to reduce heat energy loss.