Maine, USA

Stir large amounts of substrate without problems

Exeter Agri-Energy is a fifth-generation family farm in the USA with around 1,000 dairy cows. The biogas plant attached to the farm has two stainless steel digesters with capacities of 396,258 gal and 2,192628 gal

The substrate consists of cattle manure from the farm itself and food waste from the surrounding area. Manure and organic materials are mixed in the anaerobic digestion tank, heated to around 100.4 °F and stirred periodically for 15 to 21 days. The biogas produced in this process is converted in electricity on site and fed into the grid. Thus, up to 800 households can be supplied with electricity and around 300 households with heat every year. Waste produced during the fermentation process is further processed in downstream processes to produce animal bedding and plant fertilizer. 

In order to stir up such large quantities of substrate in an optimal way, four GIANTMIX AMX were installed. Thanks to an agitator propeller diameter of 5.2 ft and the low speed of 82 rpm, the agitator is ideally suited for large containers and substrates with high dry matter content. Another advantage is the horizontal and vertical adjustability of the agitator. As long as no slurry can be spread, the tank in Exeter serves as an intermediate storage. An inclination adjustment of the agitator is indispensable for optimal agitation and homogenization of the substrate even with changing filling levels. 

Why did Exeter Agri-Energy choose SUMA agitators?
"In my opinion, SUMA has more "real world" experience than any other agitator manufacturer. With the size of our tanks, we depended on SUMA´s experience to design the agitation. After some initial difficulties, we were able to work with SUMA to bring our system online quickly. The cooperation went excellent!". 
(John Wintle,  Plant Manager)