The new carbon-fiber composite agitator blade has been rigorously tested under the severe corrosive and highly abrasive conditions of extraction tanks and has demonstrated stable operation, with a service life more than three times that of conventional CD4MCu and 2205 metal impellers.

The new carbon-fiber composite agitator blade completely eliminates issues such as reactor fouling, reduced production capacity, and fine calcium sulfate particles clogging the filter cloth—problems that typically arise from wear on metal impellers. It is the preferred choice for efficient and stable operation in highly corrosive, solids-containing, and demanding process environments.

Case:

◆Wear of the agitator impeller in the extraction tank has a significant impact on mixing intensity and, consequently, on the tank’s production efficiency and phosphorus recovery rate. At a large chemical plant, after one year of operation, an inspection of a carbon-fiber-composite agitator impeller revealed that the blade tips remained intact with no signs of erosion whatsoever (as shown in the figure below).

Commonly used CD4MCu and 2205 stainless steel agitator impellers: after six months of operation, the impeller’s rotational diameter decreases by 10%, and the impeller blade width decreases by 3–5%, resulting in a reduction of at least 20% in mixing intensity. The resulting production impacts are as follows:

◆ Uneven mixing of the medium leads to accelerated scaling in the reaction vessel, resulting in a decrease in effective volume and reduced production capacity.

◆ Calcium sulfate crystallizes more rapidly in the reaction tank, and the incomplete growth of fine, sharp crystals readily clogs the filter cloth.

◆In practice, each time the agitator impeller blades are replaced during the annual overhaul, system operation returns to normal; however, performance gradually deteriorates after about six months.

The impeller peripheral speed of the phosphoric acid slurry pump exceeds 20 m/s, with a service life of up to two years. The agitator blades operate at a peripheral speed of 7–8 m/s, ensuring a significantly longer service life under the same process conditions.

It takes the operating cycle of at least three sets of metal blades to equal that of a single set of carbon-fiber composite blades; moreover, considering the impact on system operation and production output, opting for carbon-fiber composite blades is the more scientifically sound choice.