These units, fabricated in several sizes to suit the site-specific flow rate requirements, enable efficient oxygen dispersion under high shear (velocities of up to 10 m/s within the unit) and pressure (~4 bar). Furthermore, the shear exposure reduces boundary layer resistance which influences most solid / liquid reaction rates, enhancing the reaction kinetics. Some basic elements are described below.
The required degree of oxidation is determined through testwork in a laboratory unit. Slurry from the tank is pumped through the Aachen unit(s) and returned to the tank. The concept of cross-flow leads to the term “pass or passes”, a term used from testwork to define the required level of Aachen unit deployment. As mentioned before, one pass is obtained if the slurry pump rate through the Aachen™ unit(s) equals the volumetric flow of the plant. By way of example, if the plant processes 500 m3/h and the Aachen unit(s) receive the same from the slurry pump, 1 pass is obtained. Should the slurry stream through the Aachens reach 2500 m3/h, 5 passes would be reached.
Potential applications are:
MMSA will, based on the envisaged degree of technology deployment and related input requirements, assess the OPEX cost versus expected revenues. The parameters considered include power cost, oxygen cost and MMSA lease fees. CAPEX issues are not usually considered (the Aachen™ technology is normally supplied on a lease contract, including maintenance).