Vacuum Mixing Reactor: An All-in-One Solution for Diverse Industrial Processes

A Representative Case: Calcium Soap Production

Solid-liquid reactions hold a significant place among chemical reactions. They generally demand intimate contact between solid and liquid reactants to attain quantitative conversion in the shortest time feasible. Here, we will take a detailed look at the production of calcium soap.

Both the reaction and the vacuum drying process can be accomplished simultaneously within the mixing reactor. Calcium soap is a type of hydroxide formed by the reaction of fatty acids with metal oxides or other substances. Chemically speaking, this transformation is a classic acid-base reaction. The fatty acids employed are commonly sourced from vegetable fats or oils. Technologically, a crucial component of calcium soap is Metal Stearate, which finds various industrial applications due to its distinct properties. For instance, Calcium Stearate, Zinc Stearate, or Magnesium Stearate are utilized as lubricants, separating agents, stabilizers, or hydrophobic lubricants, and so on.

Although fatty acids and metal oxides or hydroxides are all in solid form, at the molecular level, the ion mobility in the solution is not sufficient for these solids to react with each other within an acceptable time frame. To enhance their reaction speed and reactivity, the addition of water is necessary. When the temperature of the added water reaches 150°C, the exothermic reaction only takes a few minutes to occur. To ensure complete conversion, vigorous mixing is of utmost importance. This is the sole means to guarantee that all fatty acid particles come into full contact with metal hydroxide and water, thus facilitating the reaction.

Since calcium soaps are usually further processed into anhydrous solids, it is essential to use drying methods to eliminate the added water and the by-products of the water reaction. After the chemical reaction is completed, the pressure gauge releases the pressure inside the reactor and adjusts it to a vacuum condition. The agitating element ensures turbulent mixing and efficient heat transfer, which allows the wet surface of the calcium soap to dry gently and rapidly. The high-speed choppers on the side of the reactor are capable of breaking up any lumps, enabling the quick removal of the water trapped within them.

Structure and Working Principle

The S&L mixing reactor is made up of a circular cylinder, a plough agitator, high-speed choppers, a drive system, an external jacket, a pulse dust collector, and a discharge valve. During operation, the materials will generate a centrifugal throwing convection, and the high-speed choppers can break up the materials that tend to agglomerate. The mixer vessel body is designed to meet the requirements of full vacuum and pressure release during the reaction process. Moreover, the external jacket can heat the materials to reach the desired reaction temperature. During the reaction, hot air and dust are produced. The dust collector on top of the mixer separates the gas from the solid powder and pumps out the moisture, thereby accelerating the drying process. We have incorporated a motor with sufficient power and a Variable Frequency Drive (VFD) to handle different shaft speeds during the reaction. In the scenario of the most intense reaction, the shaft rotates at a low speed while the torque reaches its maximum value. At the end of the reaction, the shaft speed increases to achieve the final mixing uniformity.

Conclusion

Following a liquid-solid chemical reaction, the product is commonly dried as the subsequent processing step. As per customer requirements, these two steps can be carried out on a single machine. Our mixer is capable of accommodating all the pressure and temperature ranges that occur throughout the entire process. Additionally, it can be customized according to specific circumstances, making it suitable for a broad spectrum of different applications.

Applications

Foodstuff industry (for drying purposes)

Plastics industry (in drying, coating, and cooling operations)

Chemicals industry (used for drying, cooling, pelleting, and extracting)

Environmental protection industry (for drying, pelleting, and extracting tasks)

Pesticide industry (involved in drying, cooling, and coating processes)

Building materials industry (for drying applications)

Metallurgy/ mining industry (engaged in drying, cooling, and pelleting activities)