Waste is a global issue, and today we all recognise the importance of working towards ‘zero-waste’ by reducing, reusing and recycling wherever we can. A surprising and often under-reported waste issue is food, with around 30 per cent of the global food supply lost or wasted each year, according to the United Nations’ Environmental Program.
In these facilities, biowaste (plant and animal material) is separated from general municipal waste and used to produce biogas, a renewable source of energy, and biomatter, used for fertiliser.
The recycling process involves crushing the organic waste and mixing it with water, producing a sludge-like substance. This sludge is then broken down by bacteria in an oxygen-free environment, a process known as anaerobic digestion.
An anaerobic digester is essentially a large fermentation tank where the sludge ferments for between 10 – 30 days, creating ‘biogas’, primarily a blend of methane and carbon dioxide.
With minimal processing, this resultant biogas can be utilised for combined heat and power (CHP) operations or converted into electricity using a combustion engine, fuel cell, or gas turbine.
Large-scale biogas plants that require large fermentation and storage tanks mean that much of the ancillary processing equipment is also located outdoors, so they are exposed to considerable environmental stresses. Facility and maintenance managers in these plants must ensure their processes can operate efficiently despite constant exposure to UV rays, temperature fluctuations, and the effects of wind and rain.
One of the most common pieces of equipment located outdoors is a separator, such as a sieve or filter press, which is used in the final step of the biowaste processing process. Once the biogas has been harvested from the anaerobic digester, the solids in the fermented sludge must be separated from the liquid to enable purification of the liquid and drying of the solids (or ‘digestate’) for use as fertiliser.
In this particular installation, flexible connectors are used between the inlet and outlets of the sieves, but the vibration of the sieves presented challenges for standard clamped flexible connectors.
Because they were attached to the outside of the pipes, the clamps were unable to prevent seepage of the liquid component during the separation process. They also did not last long in the exposed outdoor setting.
The maintenance staff required strong, resilient, and flexible connections that could withstand exposure to the elements while containing the liquid component of the separated waste without leaking under vibration.
To solve this challenging issue, local BFM® fitting distributor, Masanes Servindustria SA, recommended installing BFM® fittings on the two outdoor sieves. Each sieve has one inlet for the sludge and two outlets - one for the liquid and the other for the solids.
Outdoor conditions can be harsh on any flexible plastic material, which is one reason the chosen material was BFM® Seeflex 040E, a particularly strong and flexible ether-based urethane exclusive to BFM® fittings.
The design of the BFM® fitting system ensures there are no leaks because the connector is snap-fitted on the inside of specially shaped spigots welded to the connecting equipment.
Even with the vibratory movement of the sieve and the location being outdoors with no protection, the BFM® fitting connector system has continued to work perfectly at the plant for many years, eliminating leakage and keeping the plant and machinery as clean as new.
If you need help with an outdoor or sieving application, contact us.