Atlas Copco compressor aids Norfolk waterway de-silting

An Atlas Copco compressor is at the heart of an aeration system using compressed air to agitate the water and overcome the build up of silt against the tidal doors that protect the guillotine gates of the Denver Sluice on the River Great Ouse, near Downham Market in Norfolk.

The sluice controls the water levels over parts of the fens and prevents high tides from flooding low-lying areas. Over the past couple of years the Environment Agency has had to dredge up to four metres of silt from in front of the gates and downstream of Denver Lock because only a limited amount of water had been allowed to flow from the three 'eyes' of the sluice due to a prolonged period of dry weather. The decision to bring the 'eyes' which include the upstream guillotine gates back into full service was hampered by the inability to move the silted up tidal doors (mitre gate type) protecting them.

Rob Barker, the Project Manager from the Environment Agency, Anglian Region, sought the expertise of their NEECA Framework Consultants, Royal Haskoning, to develop his concept for an aeration system. The task fell to David Goodman, Principal Mechanical Engineer with Royal Haskoning based in their Leeds Office, who developed the initial concept to outline design stage and produced the specification and tender drawings for the system. The final details for the design, along with the supply and installation of the equipment was provided by Atlas Copco's main distributor in the area, Anglian Compressors, based in Peterborough.

Commending the support received David Goodman said: "The level of assistance provided by both Anglian Compressors and Atlas Copco's technical team was excellent and greatly contributed to the success of the project; and as expected the equipment supplied and quality of installation was first class."

The complete installation comprised a GA15 VSD 15 kW rotary screw compressor together with an LV500 air receiver and a PD 60 oil filter, housed in a purpose-built GRP kiosk located on site, together with associated pipework and control valves/manifolds.

The aeration system itself comprised three concentric loops of galvanised steel pipework installed in front of each gate. Four mm holes were drilled at 100mm intervals in sections of the pipework loops with each concentration of holes covering a different section of the individual gate/sill. A set of ball valves was configured to allow independent control of each loop for concentrated aeration at higher pressures and also flushing of the system in either direction.

The decision to install a variable speed drive version of the GA15 compressor - capable of delivering air at the rate of 16 - 48 l/s at a pressure of 7 bar(e) -  was influenced by the ability of the VSD compressor to match output to demand for optimum energy efficiency and to minimise starting currents without energy penalty.

The system is now operated regularly during outgoing tides which carry the silt downstream and all the indications are that the system will continue to be effective in keeping the front of the tidal gates free from any silt build-up.

Commenting on the project, Rob Barker said: "The Environment Agency is very pleased with the early results of the compressed air aeration process.  We would certainly consider installing similar systems in other locations experiencing this type of problem."

For further information contact John Forman at Atlas Copco, e-mail: gba.info@uk.atlascopco.com or view website: www.atlascopco.co.uk  Refer to page 72

Companies considering new component cleaning and degreasing equipment
can now take a machine on free loan to test its effectiveness and operation

Companies considering new component cleaning and degreasing equipment can now take a machine on free loan to test its effectiveness and operation.

Layton Technologies is offering a Blueseal sealed solvent cleaning system as an on-site demonstration machine for companies who want to continue cleaning with chlorinated solvents such as Trichloroethylene or Perchloroethylene.

The machine is available to companies who want to test out its features at their own site. Layton will provide the machine free of change, together with operator training. Delivery and connections to services need to be arranged by the user company.

Chris O'Rourke, Layton's sales manager explained that the demonstration machine is already in demand as more companies look to ensure that their component cleaning is compliant and safe. "We already have a demonstration facility at our UK manufacturing base in Staffordshire, which allows companies to visit us to see how the equipment works and to conduct trials, but this on-site machine allows companies to also have a Blueseal system on their premises to enable wider understanding of the system".

The Blueseal system is a safe and environmentally compliant component cleaning system which can be configured for use with Tric, Perc and some specific hydrocarbons and modified alcohols. It complies with latest regulations (SED) and the solvent suppliers Voluntary Industry Code (VIC). 

The system has a hermetically sealed process chamber which features spray, vapour and full immersion cleaning with ultrasonics, and super-fast vacuum drying. It has a closed solvent recovery process with full carbon adsorption and automated regeneration all within a compact package, designed to deliver extremely low solvent use with almost zero emissions and exposure levels.

Layton Technologies is a leading UK component cleaning systems manufacturer, who design and build cleaning plants using either solvent or aqueous technologies, specialising in highly demanding applications including healthcare products, electronics, aerospace and precision engineering.

For further information, e-mail: ianparry@laytontechnologies.com or view website: www.laytontechnologies.com    Refer to page 78   

Netzsch Pumps improve service life
feeding the Goosey Lodge Power Plant

Two NM063SS01L06B pumps from Netzsch Pumps Ltd are being used by Ancillary Components Ltd in Northampton to improve service life feeding the Goosey Lodge Power Plant.

The materials that are fed through the new pumps into the plant are all biomass including animal by-products and wastes, blended to typically 50% dry solids content by weight.

The plant runs continuously except for brief outages for planned maintenance and the pumps require a stator change after about six months which is twice as long as expected and considerably longer than the originally installed pumps could manage.

The secret of the Netzsch pump lies with the patented iFD stator, which allows the elastomer to flex when in contact with abrasive particles, thereby reducing the abrasive effect on both itself and the metal rotor. The iFD stator also carries an environmental pedigree as it not only allows for smaller drives, due to the lower breakaway torque, it can also be easily recycled; in fact it was developed in conjunction with the German Environmental Foundation (DBU). The iFD stator is also easily retro fitted to most modern NETZSCH pump models. (Refer to the picture above).

For further information, e-mail: sales@npu.netzsch.com or view website: www.netzsch.com

Energy storage system deals with sudden draws on the grid

Time for a quick cuppa? When the final whistle blows, demand for electricity usually soars, causing a headache for energy companies.

Researchers at the University of Leeds and the Chinese Academy of Sciences have now found a way to manage these short-lived draws on the electricity grid far that could halve the fuel needed.

The amount of electricity drawn from the national grid varies enormously at different times of day. It usually peaks in the early evening for a couple of hours after the mass exodus from school and work. Short-lived spikes are also common after major televised sporting events, during commercial breaks and in the morning hours.

But matching the highs and lows in demand with a steady supply is a major challenge. Energy companies typically top up a 'base' supply of energy with electricity from power plants that are just switched on to cope with the peaks. However, the gas-fired generators often used to feed these peaks are notoriously inefficient, expensive to run and sit idle for long periods of time. In short, the system wastes both energy and resources.

University of Leeds Professor of Engineering, Yulong Ding, and colleagues are proposing a more environmentally friendly system that would also be cheaper to run. Crucially, the system would store excess energy made by a plant supplying the 'base' demand and use this to supply the 'peaks' in demand - as and when they happen.

"This integrated system is truly novel," said Professor Ding, who led the research. "Because we are storing the excess energy for later, there is less need to ramp up the output of gas-fired plants whenever a peak in demand is expected, generating electricity that may simply not be used."

The key idea is to use excess electricity to run a unit producing liquid nitrogen and oxygen - or 'cryogen'. At times of peak demand, the nitrogen would be boiled - using heat from the environment and waste heat from the power plant. The hot nitrogen gas would then be used to drive a turbine or engine, generating 'top up' electricity.

Meanwhile, the oxygen would be fed to the combustor to mix with the natural gas before it is burned. Burning natural gas in pure oxygen, rather than air, makes the combustion process more efficient and produces less nitrogen oxide. Instead, this 'oxy-fuel' combustion method produces a concentrated stream of carbon dioxide that can be removed easily in solid form as dry ice.…./Continued on the next page.