在高低温小型实验室中，氯化钙干燥设备通过喷雾干燥机实现产品的干燥过程。喷雾干燥机利用热风来实现雾状产品的干燥，热风由喷雾干燥塔塔口进入塔内，完成干燥工作后的废气由引风机排空。在喷雾干燥机工作的过程中，控制热风温度和出口温度（排风温度）非常关键，这些因素决定了产品质量以及松密度等因素。
实验中，我们发现排风温度与产品水分含量有关，因此应按产品容许水分来决定。热风温度越高，经济性越好，但过高的热风温度会造成产品质量变劣，因此需要在保证质量的前提下适当提高。
喷雾干燥机中的热风温度对产品松密度产生显著影响。高温热风有产生低松密度倾向，这是由于快速湿气膨胀并促进气球状中空颗粒形成。但如果要求高松密度或实心颗粒，则不应使用高温热風与新形成的湿滴接触。在化学药品的干燥中，hot wind temperature can reach up to 538℃, and the product particle size is large; while in food spray drying, the hot wind temperature is generally not more than 177℃, resulting in a smaller diameter of hollow particles.
The dryness density of the spray dryer also known as stacking density plays a decisive role in the drying effect. Therefore, determining the dryness density is an important task. Generally, when designing a spray dryer, we should set the dryness density first so that products can achieve better drying effects.
When selecting a spray dryer for laboratory use, we need to consider several factors: (1) device type; (2) additives' influence; (3) feed concentration; and (4) heat and exhaust temperatures. The most commonly used experimental-type spray dryers are centrifugal-type and dual-flow-type spray dryers. Centrifugal-type has high drying speed but larger equipment size and higher cost. Dual-flow type has smaller volume and less clogging risk with good appearance design.
In summary, experimental-scale spray dryers have been widely applied in various fields such as food industry, pharmaceutical industry, nanoscale powder application etc., especially for ordinary spraying drying process for pure solution or colloidal solution with uniform solid state at final stage. For example Chen et al tested experimentally on improving nutrition value of Dikarya by using this method with optimal parameters: inlet temperature of 70 ℃、feed flow rate of 0.6 L/h、atomization pressure of 92 MPa、inlet air temperature of 172 ℃ which results in nutrient retention rate of 60.26%, water content at 3.2% and antioxidant preservation ratio at 83.92% with dissolution time within seconds；Yue used similar technology to prepare honey apple powder；Yuan did similarly when treating beer waste yeast residue；Gong et al studied impact factors affecting oilseed rape flower extract during its spraying drying process；Liu compared techniques like freeze-drying vs spraying-drying for making honey sap powder concluding that although freeze-dried had better nutrients retention yet spraying dried was more energy-efficient & environmentally friendly hence preferred option.
In conclusion these devices are versatile tools essential in many industries where precise control over moisture levels & particle sizes matter significantly affecting final quality output.
