The drying equipment, known as “dryer” as well, refers to the equipment for drying operations, which can vaporize the moisture in wet materials by utilizing heat energy in order to obtain relatively dry materials. There are two main purposes for using drying equipment. It is not only beneficial to the package, storage and transport of products, but also capable of relatively extending the shelf life of biological products due to many biological products can keep stable in a state of containing less moisture. The drying equipment is mostly used in the final process of product production, and plays an essential part in many field, such as biological, chemical and pharmaceutical fields. The selection of drying equipment as well as the the drying method has a great influence on the quality of products. There are several commonly used drying equipment, including freeze drying ovens, vacuum drying ovens and blast drying ovens, which are involved in three different drying methods. When selecting the proper drying equipment, several principles can be followed. Firstly, the properties of materials should be given consideration to. Secondly, it should meet the requirements of product purity and quality. Last but not least, the output and working conditions should be considered as well.
The drying process of water-containing materials in drying equipment can generally be divided into three stages:
(1)Accelerating the heating stage. At this stage, the heat absorbed from the heat-carrying medium is mainly consumed in heating and raising the temperature of the material.
(2)Constant-speed constant temperature stage. This is the constant temperature stage of constant drying at the maximum evaporation rate.
(3)Decelerating and heating stage. The water evaporating from the surface of the material has begun to decrease, so it is the slow-down drying stage.
According to the operating pressure, it can be divided into two types: normal pressure and vacuum;
According to the operation mode, it can be divided into two types: intermittent operation and continuous operation;
According to the heat transfer principle, it can be divided into conduction heating, convection heating, radiation heat transfer and high frequency heating;
According to the heating method, it can be divided into two types: direct heating and indirect heating;
According to the structure, it can be divided into spray dryer, fluidized bed dryer, air dryer, paddle dryer, box dryer and rotary flash dryer, etc.
Hemp drying is considered as an essential and necessary part of hemp processing for CBD oil extraction. After being harvested, hemp should be dried as soon as possible to avoid deterioration of the plant and to reduce the loss of CBD content. With hemp and CBD oil showing more benefits and becoming more well-received, the drying equipment for hemp has been further developed and advanced in order to gain a high-quality CBD oil. Only when the proper drying equipment is selected can hemp be dried efficiently and correctly. Taking all factors into account, there are several drying equipment applicable for hemp drying, including the vacuum drying ovens, blast drying ovens as well as freeze drying equipment.
Freeze Drying Equipment
The freeze drying equipment is one of the common and essential drying equipment, which is based on the freeze drying method. The working process can be simply described as follows. It can pre-freeze materials that need to be dried in order to make materials in the solid form. Making use of the direct sublimation property of ice, it can dehydrate materials and dry them into powder under conditions of low temperature and low pressure. The freeze drying equipment is usually used to dry heat sensitive materials that are thermally unstable and easy to oxidize and deteriorate, as well as the materials that are unstable in aqueous solutions and need to maintain biological activity. The freeze drying equipment possesses both pros and cons. On the one hand, it can get rid of more than 95-99% moisture. Some easily oxidized materials can be prevented from oxidizing and can be preserved for a long time owing to the vacuum working condition. On the other hand, the freeze drying equipment is complicated and the process control requirements are relatively high, with a high energy consumption and long time for freeze drying. As one of the types of necessary drying equipment, the freeze drying equipment can be widely used in biological, chemical and pharmaceutical fields.
Freeze Drying Equipment for Sale
Vacuum Drying Oven
A vacuum drying oven is regarded as “green drying equipment” widely used in biochemistry, chemical industry, pharmaceutical field, health care, environmental protection and other areas. It will dry materials under vacuum condition. The pressure in the drying chamber is reduced result in the water or solvents can evaporate at a low temperature. It is especially suitable for rapidly and efficiently drying heat sensitive materials, easily decomposed and oxidized materials and complex materials. Compared to other drying equipment, a vacuum drying oven possesses a great number of merits. Not only is it capable of drying and sterilizing materials simultaneously, but also can damage less active ingredients to ensure that products have a better quality. Further, it can ensure a safer operation result from that it can completely eliminate the possibility of oxides exploding in heat under vacuum or inert condition. Given consideration to the above factors, it’s well recognized that vacuum drying ovens are environmentally friendly and considered as green drying equipment.
Vacuum Drying Oven for Sale
Blast Drying Oven
A blast drying oven is applicable for drying, sterilizing, and baking in laboratories, scientific research institutions and industrial and mining enterprises. The main characteristic of this type drying oven is “blast”, meaning blast drying ovens can be connected to the outside air. The air in the drying oven can circulate horizontally and convectively under the function of a blast engine. After being heated on a electric heater, the air is sent into the working chamber. Then the air is sent to the electric heater again. By keeping air being heated cyclically, it can keep the temperature in the chamber more even. The hot air in the working chamber can heat the wet sample materials so the moisture can be vaporized to mix with the hot air. Though a blast drying oven can be used for drying, it isn’t suitable for drying flammable materials, or it may cause explosion. The proper drying equipment should be selected according to the specific conditions.