The Pearth™ digester gas mixing offers economical, reliable mixing in both small and large diameter tanks. It can reduce energy costs while providing thorough digester mixing, superior floating solids controls as well as the ability to control settling zones for digested solids.

In very small diameter digesters (8m or less), one point of gas energy input is usually sufficient to mix the tank contents. In larger diameter tanks, the Pearth™ employs lances to sequentially inject gas into a series of micromixing zones throughout the tank. Since energy dissipates as it moves away from its source, using a greater number of small, sequencing mixing zones reduces energy costs and improves mixing performance. The absence of intense energy from a given zone during the sequencing cycle has no effect on the digester operation due to the relative slow reaction and settling rates experienced in anaerobic digestion.

The sequential discharge feature of the Pearth™ system develops a variable mxiing pattern in the digester unlike typical gas, mechanical or recirculation system features a fixed mixing pattern. A fixed mixing pattern means that the velocity vectors associated with the flow, which is developed by the mixing system, have a fixed direction and intensity. As a result of this, dead spots may be formed by opposing vectors, wall effectors or by the effects of piping or other obstructions. To overcome this problem, fixed pattern mixing system require more energy in the digester, which increases energy costs, unlike the Pearth™ system.