The legislative requirements for meeting clean air emissions targets, which have become increasingly strict over the past few years, exist for safe regulation of containers with problematical content; either from a toxicity or odour control perspective. These requirements impact upon a number of industries and situations; including areas of municipal waste-water disposal, the chemical, pharmaceutical and food processing industries as well as farm based material storage for anaerobic digestion and slurry management.
Given that much of this legislation has been put in place recently, this has presented challenges in terms achieving a cost effective upgrade solution for plant and operations management. The Lipp stainless-steel diaphragm is the perfect choice for retrospectively covering existing steel or reinforced concrete containers as well as Lipp’s own Dual-Seam System stainless steel containers.
The self-supporting, light-weight, diaphragm design is made of stainless steel – with high mechanical strength and resistance to ageing – which enables containers with diameters of up to 100 m diameter to be spanned. The sheet material simultaneously assumes a supporting shape that closes off the internal space and can withstand snow loads and high winds. Martin Grant, the UK Sales and Marketing Manager commented, “In light of the ever more stringent legislation covering air quality and the new Totex value accounting methods adopted by the UK Utilities, the ability to upgrade existing storage capacity with a cost effective roofing solution is a welcome one within the UK market”.
The Lipp stainless-steel diaphragm cover is corrosion-resistant, gas and vapour diffusion resistant and is not susceptible to UV radiation or damage. The lightweight design of the diaphragm is excellently suited to covering volatile substances. Welding work at the installation site is eliminated by prefabricating the diaphragm cover at the Lipp manufacturing plant. The completed diaphragm is then shipped to the site for fitting. As the design of the completed sheet stainless steel diaphragm is both strong and highly flexible, the tank cover arrives on site as a large roll on a transporter. The cover is then fitted and sealed to the existing tank with a bolted and sealed ring which provides a water and gas tight seal at atmospheric presure.
Once installed on to the tank the diaphragm roof can then be subsequently fitted with various valve and pressure relief systems, depending upon the application requirements.
As well as having applications within water utility and processing plant applications, the tank covers can be used for on-farm slurry tanks as a retro-fit. This means that slurry tanks can be insulated to prevent rainfall diluting and increasing the volume of stored slurry and can be fitted with off-gas safety valves ensuring that biogas build up within the sealed slurry tank is safely managed. Retro-fitting a stainless steel cover considerably extends that life of the tank without the unwanted cost of replacing the existing open tank with a new covered one.
The innovative diaphragm cover system has been used in mainland Europe for a number of years and is now available within the UK and Ireland through Lipp and has recently been fitted to a new large-scale processing plant in Wakefield.