The development of water reducers has a long history, evolving from early lignosulfonates to the widely used β-naphthalene sulfonate formaldehyde condensate sodium salt (SNF) and sulfonated melamine formaldehyde condensate sodium salt (SMF) high-efficiency water reducers. Nowadays, both domestically and internationally, a new generation of high-efficiency polycarboxylate water reducers has been developed. These new reducers are characterized by low dosage, high water reduction, high enhancement, low alkali, low shrinkage, high slump retention, and environmental friendliness, gaining increasing market favor. However, due to the characteristics of the production process, polycarboxylate water reducers have notable drawbacks. They are commonly supplied as a 22% aqueous solution, making long-distance transportation costly and unsuitable for applications requiring powdered materials, such as dry-mix mortar.

There are two main reasons for this issue: first, the polymerization process of polycarboxylate water reducers results in high water content, typically between 45% and 78%. Converting them into powder requires high energy consumption and incurs expensive processing costs, posing significant challenges for further processing. Second, the relatively low molecular weight of polycarboxylate water reducers means that the powder's softening point is low. Prolonged processing temperatures above the softening point can lead to side reactions like amidation of reactive groups, causing the product to yellow and reducing its dispersibility in concrete.

Our company's centrifugal spray dryer addresses these drying challenges for water reducers by solving the following issues: 1) material sticking to the walls; 2) yellowing of the color; 3) ineffective air sweeping; and 4) moisture regain in the final product.

The specialized dryer for water reducers uses high-temperature hot air generated by the hot air furnace, which enters the drying chamber through the volute channel at the top. With the help of the hot air distributor, the hot air creates a uniformly rotating airflow that quickly enters the drying chamber, ensuring uniform air distribution inside the tower. Liquid materials like water reducers are atomized by a high-speed rotating atomizer into fine dispersed mist. This mist comes into contact with the swirling hot air, causing rapid evaporation of moisture, allowing the material to dry in an extremely short time, resulting in hollow, thin-walled spherical products that can quickly dissolve in water.

In recent years, our company has accumulated extensive experience in the drying process of water reducers (naphthalene-based, anthracene-based, lignin, etc.) and has developed several technologically advanced pieces of equipment tailored to the characteristics of water reducers.

To address the shortcomings of the current water reducer drying technology on the market, we have thoroughly researched the product characteristics and incorporated modifications from our centrifugal spray dryers used in other fields for heat-sensitive materials. This led to the development of a specialized spray dryer for water reducers, effectively solving the processing challenges of polycarboxylate water reducers. The resulting powder is white with good flowability, ensuring excellent dispersion and slump retention in cement.