A moisture absorbent is any substance that absorbs moisture from the air, also known as a desiccant.
According to the state of the moisture absorbent, it can be classified into three types:
a solid moisture absorbent, a liquid moisture absorbent, and a gas moisture absorbent.
The solid moisture absorbent dehumidifies the humid air by the adsorption principle;
The liquid moisture absorbent utilizes the absorption principle to achieve the dehumidification effect of the air;
The gas moisture absorbent is compressed air, and the air is mixed with the humid air to achieve dilution and dehumidification of the humid air.
Commonly used solid moisture absorbent
Silica gel: Alias silicic acid gel, a highly active adsorbent material, is an amorphous material. The main component of silica gel is silica, which is chemically stable.
Does not burn. Silica gel is a clear or milky white granular solid. It has an open porous structure, strong adsorption, and can adsorb a variety of substances. Dilute sulfuric acid (or hydrochloric acid) is added to an aqueous solution of water glass and allowed to stand to form a hydrous silicic acid gel to be solidified. The Na+ and SO42-(Cl-) ions dissolved in the electrolyte are removed by washing with water, and after drying, silica gel is obtained. If the water is absorbed, part of the silica gel absorbs about 40% or even 300%. Used for gas drying, gas absorption, liquid dehydration, chromatography, etc., also used as a catalyst. For example, cobalt chloride is added, it is blue when it is dry, and it is red after water absorption. Recyclable and reusable.
Calcium Chloride: A salt consisting of chlorine and calcium with the chemical formula CaCl2. Slightly bitter, tasteless. It is a typical ionic halide that is white, hard crumb or granules at room temperature. Anhydrous chlorination because it readily deliquesces in the air
Calcium must be stored in a sealed container. Calcium chloride and its hydrates and solutions have important applications in food manufacturing, building materials, medicine and biology. Calcium chloride has a prominent adsorption capacity for ammonia and a low desorption temperature, and has great application prospects in the adsorption separation of synthetic ammonia. However, since calcium chloride is not easy to form a stable porous material, the contact area with the gas ammonia is small, and it is easy to expand and agglomerate during adsorption and desorption, so that it is difficult to put it into practical use in this respect. Carrying calcium chloride on a high specific surface carrier can greatly increase the contact area between calcium chloride and gas ammonia. Related studies have shown that a composite adsorbent prepared by supporting calcium chloride on a molecular sieve has better adsorption performance and stability than a single adsorbent.