In the use of heat pump dryer processing agricultural products, the specific drying process, what is the main steps?

First, product preheating

In the preheating stage, because the initial temperature of the drying room is low, the water evaporation of the agricultural products is less, so the humidity is relatively low, only the heating does not need to get wet, so that the agricultural products can quickly heat up to the internal and external temperature balance, which is generally about 5-30 minutes.

Two, finish processing

The main role of finishing is to maintain the original color and appearance through high temperature destruction and blunt the oxidase activity in fresh goods, so that the agricultural products can also play a role in the promotion of a part of the fragrance, in addition to deodorization and sterilization effect. Common need to finish the agricultural products are: tea, honeysuckle, day lily, Hangzhou white chrysanthemum, Beijing chrysanthemum, Chinese prickly ash, star anise, green vegetables and so on.

Three, dehumidifying color

Dehumidified color is an effective way to preserve the color of agricultural products, mainly is achieved by rapid dehumidification at low temperature, avoid the temperature should not be too high, the temperature setting interval is 45℃ ~65℃.

Four,Product ripening

Maturity refers to the artificial provision of appropriate temperature and humidity to complete the ripening of materials, composition synthesis, conversion and other processes, among which the saccharification phenomenon also belongs to a kind of ripening. Common need to mature agricultural products are: tobacco, persimmon, figs, sweet potato and so on.

Five, material contraction

Only the reasonable control of the dehydration speed of agricultural products, can play a uniform contraction role, to ensure that the product requirements of agricultural products. This stage is very high requirements, need a certain accumulation of experience, can be scientific and reasonable control.

Six, return sweat treatment

Sweat is divided into artificial sweat and natural sweat. Artificial sweat is meant to stop the heat pump drying equipment, let the agricultural products in a certain temperature, to complete the water migration balance; natural sweat is the agricultural products out of the drying room, placed in the natural environment, to complete the water migration balance.

Seven, enhance the fragrance

Body fragrance is the end stage of drying, through the role of high temperature, promote fragrance production, make the taste of agricultural products more rich and rich, improve the drying quality and value of the product, for the very high taste requirements of spices, tea, etc., all need to go through this stage of treatment.

Eight, air dry return

Air drying moisture return is very simple, after the whole drying process is completed, the material down to room temperature, make produce water to constant state, and then packaging processing, such as flower tea drying, if the water content is too low, the finished product packaging, a touch is broken, is not conducive to keep appearance, moisture after this situation can be avoided.