Heat transfer in a beef manure anaerobic digester

Mechanically agitated heat exchanger for an anaerobic digester

“…For this study, effectiveness is defined as thermal efficiency. Second, both heat exchangers have problems with plugging due to the settling of the slurry (Greiner, 1980).…”

“…To make this type of heat exchanger efficient, either a very long pipe or a bundle of pipes must be used to increase the exchanger surface area. In either case, the friction losses would be much greater and plugging would result (Greiner, 1980).…”

“…seven tanks In series). According to Greiner (1980), an effectiveness of 0.45 is the maximum that can be attained with a one pass tank. This trend can be seen at the higher flowrates.…”

“…This trend can be seen at the higher flowrates. The detention time, which Is drastically reduced, Is not sufficient to allow the exchanger to function For a multipass mixed tank counterflow heat exchanger, the general solution of the overall thermal conductance is (Greiner, 1980): Therefore, equation 10 can be revised to give (Greiner, I98O):…”

“…Effectiveness versus flowrate at various agitation rates15.8 in each tanlt Greiner (1980). developed a number of theoretical design curves to use as a guide when designing an influent to effluent counterflow heat exchanger.…”