Drying tea in a boiling layer
Tea, like coffee, is a very popular drink among consumers. Modern teas are varied in taste and aroma. There are leaf teas and powdered teas with different types of aromas and tastes, pleasing to the eye and heart.
You can go to the store and see hundreds of bright, eye-catching boxes, jars, each of which promises many pleasant feelings from the tea ceremony.
Drying technology in fluidized bed dryers
In order to keep the rich taste of the tea drink, there is a special technology for drying tea leaves.
First, tea leaves are collected carefully, left on a dry cloth or any clean surface, placed in an even thin layer. One square meter should contain about six hundred grams of tea. Tea leaves are left for twenty hours, during this time 35 percent of moisture is released from them. Using this technology in production is unprofitable, because all industrial enterprises are interested in production with big output capacity and processing products in a short period of time. Therefore, there are special drying chambers at large enterprises. The machines are used for quick drying tea with the dry air supplied. At the same time, all useful properties of tea are preserved.
Tea leaves are curled while drying, they are placed in boxes in a layer of up to 5 centimeters, and then placed in a room full of moisture with an air temperature of 24 degrees. The leaves should be kept in this room within six hours. During this time, they turn red and become bitter. This is a very important process because the taste and aroma of tea drink depend on it. The process is called fermentation. Then the drying stage begins and is performed with the special equipment. It is necessary to dry the tea until it becomes black. The best way to perform the drying process is using fluidized bed technology. This type drying chambers are used not only for drying tea, but also for finely grounding products up to five millimeters.
Structure of the fluidized bed drying chamber
The design of the chamber is simple and convenient. The upper chamber fluidizes the product, while the lower one distributes the heated air. A perforated grille mesh separates the two chambers. The equipment also has an inclined grate, where the product enters and where it is dried with supplying warm air. The grate vibrates to ensure processing all the particles of tea. After the tea is dried, hot air is expelled from the chamber through the side vents. The dried tea passed the branch pipe for further processing like addition of aromatic substances, weighing, packaging.
Fluidized bed drying technology is simple and easy to understand. It helps to reduce the drying time using heated air without losing the beneficial properties of the product.
Types of fluidized bed dryers
By the type of section, there are permanent, expanding, rectangular or round dryers. The gas distribution grid is a very important device in this type of drying machine. The speed of air feeding and the drying process depend on this device. Fluidized bed dryers have one or multiple sections. You can place and process more products with more sections. But this factor does not affect the time and speed of the operation. The tea dries evenly and after drying it is ready to use.