From Plant Engineering
Disintegration – i.e. the crushing of sewage sludge, has great potential for making sewage plants more economical and efficient. International studies show that 50% of all biogas production plants work sub-optimally and deliver poor results. A sure and quick way to change this is through the use of GSD, the ultrasonic countercurrent disintegration process developed and patented by VTA Technologie GmbH. The VTA GSD process involves the breaking down by ultrasonic oscillators of the thickened sludge flowing through the disintegration reactors.
- Low wear and tear - ultrasound oscillators elements have a useful life of more than 5 years ( > 45,000 operating hours) 4
- High flexibility in plant operation with freely configurable degrees of digestion
- Low energy consumption - high degree of digestion with low energy usage
- Trouble-free operation without clogging – smallest cross-flow aperture DN 80
- No sludge pre-treatment needed – as opposed to conventional processes that often require an expensive and energy intensive pre-treatment step (macerator!)
- Unpressurized, stand-alone operation facilitates ease of integration at almost every sewage plant
- Proven technology – VTA uses components exclusively from well-known manufacturers who have proven themselves in sewage plant operation
- Maintenance free except for normal visual inspection
- Modern controls with SPS, touch screen and remote servicing
This process involves the breaking down of thickened surplus activated sludge, which is fed to the disintegration reactor, through the use of ultrasound oscillators.This has the effect of:
- Increasing the degree of organic degradation of biogas production by up to 25%
- Increasing the production of biogas by up to 30%
- Increasing the production of electrical power by up to 30%
- Reducing sewage sludge formation and associated disposal costs by up to 20%
- Lowering the use of dewatering agents (polymers) by up to 30%
- Doing away with digester tower foam
- Effective improvements in the operation of the sewage plant from the biological standpoint (scum/bulking sludge, settleability of activated sludge, etc.) by nullifying or digesting filamentous bacteria
- Stabilising the process of biogas production, shortening biogas production times
- The VTA GSD can be retrofitted without any difficulty in virtually all biogas plants.
- Reactor/pumps and the control cabinet require around 5 m² / 100,000 PT (total number of inhabitants and population equivalents). The ceiling height should be above 2.80 m.
- Trial runs in a demonstration plant with actual sludge allow for a concrete calculation of the optimisation potential and optimal sizing of the VTA GSD.
- Almost all types of sludge can be treated using the GSD process. A solid content of 3-8% is ideal. The polymer quantity used in mechanical thickening is not relevant to the GSD process.
- 25 kHz ultrasound can be used for sludge treatment in the GSD process. The use of 20 kHz welding grade ultrasound is not required if long exposure times are chosen. This increases the useful life of oscillator elements by up to ten times.
- Delivery time for a VTA GSD is around three months, since each VTA GSD is manufactured specifically for each sewage plant.
- From experience, the amortisation period for a VTA GSD ranges from two to six years.
- VTA offers a maintenance contract to all customers.