Innovations and Developments
"Drive-through"
Tunnels
CRS have developed a design of composting tunnels with a door at both ends so that the waste can be loaded into one end and emptied at the other.
This design has been developed in response to the Animal By-Products Regulation (ABPR) and it enables a one way flow of waste through the plant. This approach, preferred by many vets, reduces the risk of cross contamination.
Air management
A self contained all stainless steel air handling unit with built in programmable logic controller. This unit is modular and requires the minimum of site installation. It is resistant to the heat and moisture contained in the compost air stream. It controls and directs the air between re-circulation and discharge to atmosphere. It activates the odour control centre when discharge to atmosphere is required.
Odour control
The project has pioneered the use of ozone for the odour destruction of composting gasses. The conventional approach to odour control is biofilters and these structures work well when correctly designed and maintained. Nevertheless, they are inherently space demanding and lack the flexibility to adapt to changing demand for odour destruction.
Ozone is a powerful oxidant and with the latest ozone technology it is not as expensive as it used to be to make. Ozone treatment of compost gas requires little of no land footprint and it is flexible and the amount of ozone can be readily increased if the odour treatment requirements are high.
Temperature Probes
The ABPR requires the constant monitoring of temperature over time. CRS have developed a special probes designed to withstand both the extreme temperatures and the arduous conditions which are experienced in a composting tunnel.
Wireless temperature logging
Dr Mullett's experience within composting facilities in Germany was that many cables from the sensors back to the data logging device failed. This was usually due to stream or water damage and it was often very difficult to trace and rectify.
CRS with its partner company, Eltek Ltd, have developed a wireless system for reporting the temperatures back to the data logger and control room. The system has dramatically improved the flexibility as well as reliability of the temperature monitoring technology.
ABPR batch management software
The ABPR requirement for info rmation about batches of material stimulated the development of a dedicated computer programme that can track a batch of compost through the in-vessel process and beyond. This software dramatically reduced the potential for process management error and automatically generates the required batch records in both electronic and hard copy format.
Drum pre-treatment
CRS have taken an old technology and put it to a different use within the waste recycling industry. Drum treatment of waste has been used for over 30 years. However, the technology has been very expensive and large scale, and it was used as a pre-treatment before landfill only.
The CRS team have value-engineered the concept of drum treatment to make it appropriate for much smaller applications and dramatically reduced the costs.
High pressure water treatments
When seeking to treat waste that is presented in bags, it is necessary to open the bags. Most mechanical devices for the opening of the bags experience damage and breakdown caused by the impact of hard objects during the process.
CRS have innovated a new way to open the bags based on the use of high pressure water.
HACCP for composting
CRS have been one of the first companies to embrace the HACCP approach to risk management in the composting field. The company's work on the HACCP plans has been complimented by the SVS vets.
Composting bays
Modular composting bays based on pre-cast A block units were pioneered by the team. The bays featured retractable roofs. This approach has subsequently become a commercial technique.
Cardboard and paper composting
Using the drum pre-treatment, the composting of both paper and cardboard waste has been both demonstrated and subsequently commercialised. CRS personnel were party to one of the first demonstrations of paper and cardboard composting within a source separated scheme. This scheme at Chatteris, Cambridgeshire achieved over 40% diversion from landfill through the incorporation of the paper/card fraction.
Wind tunnel separation of plastics from oversize
A substantial amount of trial and test work has been undertaken to examine the potential of wind tunnel separation of contaminants within compost. In the trial it was shown that both stones and film plastics can be separated from the compost. This research is not yet commercially applied as it requires a consistent moisture content in the compost. This approach is considered by CRS to offer one of the most reliable methods for upgrading the mulch fraction by the removal of plastics and the removal of inerts from the fine compost.
