The design incorporates the 3m Alfabloc walling product as the base foundation of the vessels with a concrete fixed roof structure located on to the Alfabloc’s. A higher than normal fixed roof was used to allow easy access for loading and unloading the vessels. The system is modular allowing for expansion when or if required and able to be filled and emptied from opposing ends which makes compliance with the ABP regulations much easier. The vessels are manufactured using a high specification pre-stressed concrete which is designed to be resistant to the highly corrosive environment of an in vessel composting tunnel. The doors system uses concrete L Bloc’s which are lifted in and out using a loading shovel. Each vessel is insulated inside using a specially formulated foam and then paint layer which protects the vessel and also insulates the vessel from heat loss through the roof. Roller covers are used to cover from the top of the gable and down to the top of the concrete door and this seals the vessel.

The aeration system in the vessels, were originally above ground air ducts which were used with our reverse aeration technique which greatly enhances the performance of the vessels.

The use of this technique uses the natural occurring phenomena in a compost pile to full effect aiding the degradation process. These above ground ducts are currently being replaced with our Mistral Aeration System (patent pending) which uses vertical aeration pipes placed in the vessel mechanically once the vessel is full. The Mistral System can be used in outside windrows for aeration and negates the need for turning of the compost and therefore reduces the risk of odour production at the composting site which is a major problem facing the composting industry.

Once the vessel is full the air pipes and temperature probes are inserted into the vessel and the composting programme starts monitoring the compost 24hrs per day.

The programme is designed to take the compost through stages of composting to reach the required standard to meet the ABP Regulations. The data from the probes are then recorded on to the computer to allow records to be kept of each batch of compost treated.

Once this stage has been reached the compost in the vessel is unloaded from the opposite end from filling, using a loading shovel. The compost is then matured further until it is ready for screening and dispatch from site.

A BPR validation was carried out immediately the site became operational and the site was fully licensed within 14 weeks of accepting the first batch of compost.

Operationally the site works very efficiently and the operational costs are proving to be well below industry normal which helps our customers run an efficient and profitable business using our system.