The waste water treatment plant in Stuttgart-Muhlhausen is setting up a second channel for disposing of the sewage sludge in addition to spreading it on farm land: it is to use sludge dewatering.

The waste water treatment plant Stuttgart-Muhlhausen, which is responsible for treating the waste water of the city of Stuttgart, is currently pursuing the strategy which has been adopted by all major waste water treatment plants in Germany for political reasons: it is setting up a second channel for disposing of the sewage sludge in addition to spreading it on farm land. This practice will be extended up to the beginning of 2007 to include a dewatering and drying facility before being conveyed to the block heating station Muhlhausen. After the planning order was placed, Westfalia Separator Umwelttechnik, Oelde/Sangerhausen, received an order for two decanters type UCD 755 for dewatering the sewage sludge and connecting the dryers via a sludge discharge scroll.

The new UCD 755 series is being installed for the first time in a municipal waste water treatment plant.

The decanters with an inside bowl diameter of 750 mm achieve a maximum hydraulic capacity of 140 m3/h.

At the Rybjerg Biogas plant in Denmark, Landia has installed a BioChop hygienisation unit, which meets the EC-regulation concerning animal by-products not intended for human consumption.

At the Rybjerg Biogas plant in Denmark, Landia has installed a BioChop hygienisation unit, which meets the EC-regulation No 1774/2002 health rule concerning animal by-products not intended for human consumption. A 2.5 m3 Landia BioChop hygienisation unit at Rybjerg adheres to the regulation which states that Category-3 animal by-products must be pasteurised or hygienised at 70C for at least one hour -and that the size of the solid parts must not exceed 12 mm. Landia has also developed a PLC (Programmable Logic Controller) for the control system to regulate all phases of the hygienisation process.

An integrated data logger, which has become an integral part of the Rybjerg biogas plant, registers the hygienisation time and the temperature.

The BioChop can also function as a heat exchanger, making the heated substrate easily pumpable, whilst the chopping of particles to less than 12mm ensures optimum use of the biogas plant reactor tank, resulting in increased gas production.

Two Aldec G2 decanter centrifuges from Alfa Laval have helped Yorkshire Water clear a backlog of sludge in just six months, by outperforming humus belt presses and producing a cake with 25% DS.

How do you clear 50000 m3 of sludge in 6 months? Two Aldec G2 decanter centrifuges from Alfa Laval have helped Yorkshire Water avoid a potential environmental problem at its Esholt sewage treatment Works by doing just that: clearing a backlog of 50,000 cubic metres of sludge in just six months. Covering no less than 340 acres and serving the Bradford area, the Yorkshire Water Esholt Sewage Treatment Works is the largest filter site of its kind in Europe.

Its complex of mineral filters handles the sewage generated by a total equivalent population of 600,000 in West Yorkshire and produces a humus sludge that is treated, dewatered and then mixed with wood waste to produce a rich conditioned sludge - which is then used for either agriculture or land remediation.

Until last year, this job was performed by three traditional belt presses which produced a dry cake of 18% DS on new humus and slightly less than that from old humus.

Unfortunately, the belt presses never achieved the levels of throughput for which they were originally specified and, as a consequence, a backlog of humus was continuously building up.

Matters came to a head last year when a series of breakdowns exacerbated the situation and left Yorkshire Water with the problem of how to clear an accumulation of 50,000 m3 while still continuing to cope with an average daily output from the lagoons of around 1400 m3.

Yorkshire Water has an enviable reputation for environmental awareness and, in fact, earlier this year picked up the title of Utility Company of the Year at a prestigious awards ceremony in London.

They were, naturally, anxious to clear the accumulated sludge as quickly and efficiently as possible.

'We were facing a potentially major environmental problem, 'confirms Ben Roche, Yorkshire Water Catchment Manager: 'The Belt Presses simply couldn't provide the level of performance we needed to keep pace with the output of the lagoons and the store of treated humus was reaching crisis proportions'.

Having decided that the belt presses were unlikely to provide the answer either to the immediate problem of the accumulated humus or the predicted increase in demand, Yorkshire Water decided to use the situation as an opportunity to appraise the options open to them.

For this purpose, Alfa Laval provided a test rig consisting of a standard Aldec decanter centrifuge mounted in a trailer.

Tests were carried out at Esholt and two other Yorkshire Water sites to compare the rig-mounted decanter performance against the installed belt presses.

After reviewing the test results and confirming that the decanter centrifuge had outperformed the belts by a considerable margin, Yorkshire Water opted for two Aldec G2 decanter centrifuges which Alfa Laval had just recently introduced.

'We looked at a number of decanter options but the specification of the G2 looked tailor made for our situation,' says Ben Roche: 'As important, given the need for continuous operation to clear the backlog, was the decanter reliability and Alfa Laval's quality of service'.

More compact than its predecessors, the Alfa Laval Aldec G2 incorporates a new gearbox that provides more power for less energy consumption because it maintains high torque levels over a wide range of differential speeds.

These, in turn, are governed by the volume and composition of the solids in the sludge.

With a drive system that allows both the bowl speed and the conveyor speed to be controlled independently of each other, the Aldec G2 also has the lowest power consumption, under all conditions, of any sludge decanter centrifuge currently available.

Once installed and commissioned, the pair of Aldec G2 decanters were put to work clearing the 50,000 m3 of stored humus while still handling the daily output of the lagoons.

The machines run continuously, 24 hours per day, 365 days per year, each processing an average of 30 m3 of humus containing 4% DS every hour and producing a cake with 25% DS.

They have proved equal to the task not simply in terms of clearing the backlog, but also in the improvement in cake dryness and quality which makes it easier to handle and store.

The dewatered sludge is mixed with wood waste, stored in windrows at a rate of 2 tonnes per square metre and then left to compost.

Conditioned sludge is then spread across prepared areas on the site up to a foot deep where it is seeded with grass to remove more bacteria and also thicken the product prior to its final destination, after harvest as a valuable agricultural fertiliser.

Hashoj Biogas in Demark has continued its successful relationship with Mono Pumps with the installation of a Mono Series F Muncher in their biogas plant near Copenhagen.

Hashoj Biogas in Demark has continued its successful relationship with Mono Pumps with the installation of a Mono Series F Muncher in their biogas plant near Copenhagen. The biogas plant is contracted to handle the various waste materials from the surrounding area mainly consisting of livestock manure and waste from fish farms and restaurants: this includes bones, chicken, fish, bread and vegetables. The increased plant efficiency gained as a result of the Muncher installation means that the investment has already paid for itself.

The Hashoj Biogas process requires the waste to be in a mostly liquid form when it is pumped into the digester to achieve maximum efficiency in gas production.

The waste is therefore efficiently reduced by the Muncher to a small particle size resulting in effective transportation, a more homogenous product and increased gas production.

The consequent savings in transportation costs combined with the increased production rate has meant that the unit has recovered its cost within 18 months of its installation and is now contributing to the revenue generated by this company.

The installed Mono Series F Muncher is a heavy duty, twin shaft grinder ideal for handling the various large solid items processed at Hashoj Biogas.

The twin shafts are fitted with a series of interleaving cutters and spacers, operating at differential speeds to create an effective tearing, cropping and shearing action for positive solids grinding.

The Series F Muncher can handle capacities up to 10,000 kg/h, dependent on the materials being processed, and enables waste to be efficiently reduced to granular or shredded matter with volume reductions of up to 70%.

Its independent drive shafts offer greater torque with the cutter/spacer arrangement determining the required particle size.

With the installation of the Series F Muncher the Hashoj Biogas Plant continues its partnership with the Mono distributor in Denmark, Hans Buch, who had previously installed both Mono TR Muncher and E Range progressing cavity pumps.

The new MBR Decanter from Westfalia Separator offers significant cost saving advantages and short pay back time when used for the final dewatering of sewage sludge from membrane filtration systems.

The new MBR Decanter from Westfalia Separator offers significant cost saving advantages and short pay back time when used for the final dewatering of sewage sludge from membrane filtration systems. Designed specifically to meet the demands of the growth in popularity of membrane bio-reactor technology in the treatment of waste water and purification of drinking water, combined with the need to save on sludge disposal costs, the MBR Decanter offers a proven and cost effective, plug and play dewatering solution. Capable of very high throughputs of homogenous sludge, with processing rates from 1m3/h to more than 100m3/h, the Westfalia Separator MBR Decanter achieves up to a five percent higher level of dewatering than other conventional dewatering techniques employing chamber filter presses or strainer belt presses.

Water recovery is improved and the volume of sludge requiring disposal is at least 20 percent lower with advantageous disposal costs.

The MBR Decanter can create operating cost efficiencies with a 20 percent reduction in comparative power consumption whilst the special design of the MBR Decanter means that less flocculants are needed with a potential 10 to 15 percent saving.

Overall the MBR Decanter offers operating expenses that are at least 20 percent lower than for other conventional dewatering techniques.

The MBR Decanter is designed for continuous operation eliminating the need for frequent rinsing and cleaning of filtration elements necessary with other sludge dewatering technologies.

With its compact design the new decanter from Westfalia Separator is ideal where space constraints are an issue, particularly if capital investment on new buildings is prohibited.

Working in partnership with membrane filtration system suppliers, Westfalia Separator have a number of reference installations world-wide, where increased efficiency of waste water treatments plants has been achieved using complementary membrane and centrifuge technology.

With sludge handling often the most problematic area in the wastewater treatment process, ITT Flygt has recently installed two non-clogging N-Pumps for greater efficiencies and savings in maintenance.

With the handling of sludge often the most problematic area in the wastewater treatment process, two wastewater treatment facilities in Scotland and Germany turned to ITT Flygt unit for the installation of non-clogging N-Pumps for greater efficiencies and savings in maintenance. Efficient solutions for wastewater treatment plants that handle large amounts of sludge are often expensive and complex. As treatment plants become larger and more sophisticated, problems become even more complex and costly.

That is why it is important to make the right configuration and equipment choices, especially when choosing pumps that will efficiently handle difficult sludge applications.

In two separate applications in Europe, wastewater treatment plant operators installed the ITT Flygt N-Pump to solve tough process applications.

Problematic Sludge in Scotland.

Untreated domestic and industrial sewage has long been piped out to sea along the attractive Moray Firth coast in Scotland.

This pollution has resulted in a steady decline in the fishing industry and thinning tourist arrivals.

However, thanks to a scheme put in place for Scottish Water by a consortium called Catchment, effluent from the local communities with 55,000 inhabitants is being carefully treated before discharge.

Along with this treatment process, a valuable agricultural fertiliser is being produced.

Scottish Water and the local communities decided to meet the environmental demands.

Centered at Lossiemouth, three SBR treatment plants - Oakenhead Wood, Buckie and Macduff - were built to take care of the wastewater from 22 existing pump stations along the coast.

The plants process raw effluent, using the SBR method.

This is an activated sludge process that forces bacterial breakdown of the crude sewage.

As the incoming sewage consists of up to 7% dry solids, it was important to provide a pump that could handle this problematic sludge.

Therefore, Scottish Water decided to install various sizes of the new generation ITT Flygt N-Pump with its self-cleaning impeller and high-sustained efficiency.

The Oakenhead Wood plant treats 10,000 cubic meters of raw sewage per day.

Much of this input comes from its own catchment area, but large quantities of raw sewage are also imported by tankers from other locations in the Scottish Water network.

Also, 17% dry solids (DS) sludge cakes from Buckie and Macduff are transported to Oakenhead for transformation to agricultural fertiliser pellets.

The plant has been designed with great attention to detail in order to provide trouble-free sludge handling using N-pumps.

For instance, the pipe system design is simple and imposes minimal losses for the imported sludge transfer and recirculation applications.

The suction pipe from the screened sludge tanks has been sized to present the sludge to the pump in the best manner possible.

One ITT Flygt NT 3085 MT recirculates the imported raw sludge in order to avoid sedimentation.

After screening, the sludge is pumped with a Flygt NT 3153 MT to a storage tank.

There the sludge is mixed with the incoming Waste Activated Sludge from the SBR process, using an NP 3102 MT pump.

The treated effluent is discharged to sea while the sludge cake goes to a sludge dryer where all bacteria are killed by the 220C temperature within the dryer.

This procedure transforms the sludge cake to 92% dry solid valuable fertiliser pellets ready for agricultural use.

Due to the chosen treatment process, the final effluent is of good quality and is being discharged to sea.

In parallel, nearly five tons a day of valuable bio waste granules for use in agriculture are being produced.

The choice of reliable N-Pumps has resulted in a trouble-free sludge handling.

This, in turn has brought significant savings in both capital and maintenance costs.

In all, 13 N-pumps are in operation in the Oakenhead Wood plant, as well as another eleven divided between the Buckie and Macduff treatment plants.

Installation in Southern Germany.

The municipal wastewater treatment plant in Zweibrucken, southern Germany, is a modern sequential batch reactor (SBR) treatment plant, designed for a population of 70,000.

Although modernised between 1997 and 2000, the community-owned plant faced continual problems with clogging of its three screw impeller pumps, installed in the digester to circulate sludge from the digester across heat exchangers.

Although all solid material more than six millimeters in diameter had been filtered out before the sludge reached the digester, the sludge contained 4.5% dry solids (DS), mostly fine rags and sand.

All three pumps were alternating: one always is in operation, and a second pump starts when new sludge is added to the cycle, plus a third pump acts as a standby.

Rags built up on the front of the screw impeller, compressing into larger blockages that got stuck in the screw design.

The pumps could be blocked several times a day and much time was spent by the service staff on dismounting, cleaning and reassembling each clogged pump.

It was obvious that these - under other circumstances - high-quality pumps, were not suitable for this kind of application.

Having heard of the new generation N-pump, the community turned to ITT Flygt in Germany for a trial pump.

In July 2002, one of the problem pumps was replaced by a Flygt NZ 3153 - running at 7.5 kW with a capacity of 100 m3/hour (=28 l/s).

The N-Pump was easy to install as it could be fitted to the existing piping and electrical system.

The N-pump features new designs of impeller and volute that inhibit clogging around the single vane.

As a result of the open design of the impeller and a relief groove in the volute, material which could gather on the vane is washed out before it collects up and blocks the pump.

For the wastewater treatment plant in Zweibrucken, that means not only fewer stoppages but also smoother running.

The installed N-pump has, in a very short period, led to a more reliable process and remarkably lowered maintenance costs.

ITT Flygt is the world's premier manufacturer of submersible pumps, mixers, hydro-turbine generators and aeration equipment for use in environments ranging from water and wastewater treatment, raw water supply, abrasive or contaminated industrial processes, mining and crop irrigation.

The Krohne Optiflux electromagnetic flowmeter has been installed at the Emscher Genossenschaft sewage processing plant to control the efficient combustion of filter cake in the incinerator.

The Krohne Optiflux electromagnetic flowmeter has been installed at the Emscher Genossenschaft sewage processing plant at Bottrop in Germany. The instrument is being used to maximise the efficient conversion of sewage filter cake, incinerated at the plant to generate electricity. The Emscher Genossenschaft plant has the largest digestion, drainage and dry incinerator system in Europe.

Sewage at the plant is processed into filter cake with high TS (total solid) content, which is used to fuel two waste-to-energy systems that each generate 8 MW of electricity for the plant.

To form the filter cake, sludge is drained in compartmentalised filter presses that increase the solid content from 5 per cent to nearly 45 per cent including carbon, and with a density of 1.87 kg per litre.

Accurately measuring the flow of filter cake into the incinerator within the waste-to-energy system has historically been difficult using electromagnetic flowmeters because of the large solid bodies and gas bubbles within the material.

Gas bubbles and large solid bodies can create interference in the measurement signal.

Rectifying this by using filters introduces sand grains into the sludge - these also make measuring flow rate difficult and sometimes impossible - because contact between the sand and the measuring electrodes can break the electrochemical boundary layer within the flowmeter and cause voltage jumps.

Engineers at Emscher Genossenschaft had previously resorted to using three different methods of measuring the amount of filter cake fuel fed into the furnaces; conventional electromagnetic flowmeters; theoretical feed rates of the high performance piston pumps; and measurements taken from the thermal energy generated from incineration.

However, the difference between the values derived from these measurement methods could be as much as 100 per cent.

This made it impossible for engineers at Emscher Genossenschaft to accurately monitor and control emissions because they did not know how much fuel was being burnt.

Neither did they know how efficiently the fuel was being converted into electricity.

The Krohne Optiflux proved itself capable of accurately and reliably measuring the flow of the filter cake.

The instrument is unaffected by high solid content or bubbles contained within the sludge.

Over a 30 day trial, comparing its measurement value against the volume count of the pumps resulted in a difference of just 3 per cent.

The Optiflux flowmeter uniquely incorporates three levels of diagnostics which sets new industry standards of metrological performance and accuracy.

Traditionally, diagnostic analysis within electromagnetic flowmeters has been limited to checking the device microprocessor controller or memory.

The Krohne Optiflux incorporates revolutionary 3x100% diagnostics.

These provide engineers with comprehensive data that makes it possible to anticipate and rectify potential problems before they affect production.

The 3x100% diagnostics include 100% sensor and converter diagnostics, which test the microprocessor, memory and software plus the temperature of the electronics as well as the output.

The instrument also carries out internal accuracy checks (100% out of spec) to determine that it is operating within specification.

100% application diagnostics, which exceed SIL 2 and NAMUR standards, are also carried out and displayed.

A waste management company has made dramatic savings in its sludge disposal costs by installing a CQ 3000 centrifuge supplied by Derbyshire manufacturer Centriquip.

A waste management company has made dramatic savings in its sludge disposal costs by installing a CQ 3000 centrifuge supplied by Derbyshire manufacturer Centriquip. Dorset-based, IPPC specialises in the treatment of hazardous industrial waste including sludges, water/oil mixtures, soluble oils and waste oil. Before the centrifuge was introduced, sludge produced during processing had to be transported by road to a plant in the Midlands for safe disposal: a costly operation that was quickly becoming unsustainable.

'The cost of handling and transporting sludge hundreds of miles was becoming a major problem and we needed to come up with a way of processing more of it on-site'.

said Oil and Water director Stewart Silvey.

'We approached several companies for help, but Centriquip was the only one that showed real commitment to solving our waste problem.

They provided test equipment and people to help us find the most practical solution.

All the other systems we looked at were more complex and not as cost effective,' continued Stewart.

The centrifuge enables the liquids in the sludge to be extracted for further on-site processing, including the retrieval of oils for recycling.

The solids are formed into 'cake', which can be disposed of via landfill or incineration.

Often the solids can be reclassified as non-hazardous, which further reduces the cost of disposal.

An overall reduction of around 75% has been achieved in the volume of waste material leaving the site.

Oil and Water developed the centrifuge system to be portable so it could assist their Industrial Services Division for on-site treatment.

Centriquip manufactures a wide range of dewatering and thickening equipment, primarily for handling wastewater.

The company also has the ability to service and repair any make of decanter centrifuge, often with a much faster turnaround than the original manufacturer.

A submersible Landia chopper pump has enabled one of the UK's main water companies to achieve faster and more efficient biogas production from its sludge digesters.

A submersible Landia chopper pump has enabled one of the UK's main water companies to achieve faster and more efficient biogas production from its sludge digesters. In a reception pit for septic sludge at this large wastewater treatment plant, the unique Landia knife system means no costly clogging or breakdowns, because harsh solids from septic and primary sludge are macerated before entering the pump. Designed and built with all the top quality hallmarks of 70-plus years of pump manufacturing experience, the highly durable Landia chopper pump successfully deals with any thick sludges to ensure no downtime.

Available with motors ranging from 75kW to 18.5kW, the highly efficient chopper pump has a specially designed pump casing and impeller.

This keeps the inlet opening free of impurities and produces the most effective pulverisation of particles, which often clog up weaker pumps, causing removal, cleaning, repair, inconvenience and lost production time.

Hashoj Biogas in Demark has continued its successful relationship with Mono Pumps with the installation of a Mono Series F Muncher in their biogas plant near Copenhagen.

Hashoj Biogas in Demark has continued its successful relationship with Mono Pumps with the installation of a Mono Series F Muncher in their biogas plant near Copenhagen. The biogas plant is contracted to handle the various waste materials from the surrounding area mainly consisting of livestock manure and waste from fish farms and restaurants: this includes bones, chicken, fish, bread and vegetables. The increased plant efficiency gained as a result of the Muncher installation means that the investment has already paid for itself.

The Hashoj Biogas process requires the waste to be in a mostly liquid form when it is pumped into the digester to achieve maximum efficiency in gas production.

The waste is therefore efficiently reduced by the Muncher to a small particle size resulting in effective transportation, a more homogenous product and increased gas production.

The consequent savings in transportation costs combined with the increased production rate has meant that the unit has recovered its cost within 18 months of its installation and is now contributing to the revenue generated by this company.

The installed Mono Series F Muncher is a heavy duty, twin shaft grinder ideal for handling the various large solid items processed at Hashoj Biogas.

The twin shafts are fitted with a series of interleaving cutters and spacers, operating at differential speeds to create an effective tearing, cropping and shearing action for positive solids grinding.

The Series F Muncher can handle capacities up to 10,000 kg/h, dependent on the materials being processed, and enables waste to be efficiently reduced to granular or shredded matter with volume reductions of up to 70%.

Its independent drive shafts offer greater torque with the cutter/spacer arrangement determining the required particle size.

With the installation of the Series F Muncher the Hashoj Biogas Plant continues its partnership with the Mono distributor in Denmark, Hans Buch, who had previously installed both Mono TR Muncher and E Range progressing cavity pumps.

These are operating successfully and have been efficient and problem-free since their installation, in 2003 and 2004.

When seeking to further streamline their operations and increase their productivity they turned to Mono once again to 'munch their problems down to size'.

Inditherm, the provider of innovative heating solutions, announces successful results for trials of its low voltage carbon polymer heating system at the Severn Trent Minworth Sewage Treatment Works.

Inditherm, the provider of innovative heating solutions, announces successful results for trials of its low voltage carbon polymer heating system at the Severn Trent Minworth sewage treatment Works, near Birmingham, UK. The trials have conclusively demonstrated that uniform heating of sewerage sludge pipelines at the plant has solved a significant problem with the accumulation of fatty substances on the inside of pipe walls. Minworth Sewage Treatment Works (STW), situated to the South West of Birmingham, serves a population of over 2.5 million.

Until now, Severn Trent has experienced problems with the build-up of fatty deposits in the discharge pipework from the Centrifuge Thickening Plant.

This accumulation is especially acute in bends, valves and pumps where it leads to a gradual loss in plant performance and, ultimately, the need for regular maintenance shutdowns.

Mark Vine, a Senior Technician at Minworth, explains: 'I like to use the human body to illustrate the problem, and the Inditherm solution.

The vital supplies to our sludge digestion plant were, quite literally, being restricted by grease and fat deposits, just as cholesterol clogs human arteries.

A gradual thickening of the pipe walls leads to restricted sewage flow, resulting in a reduced throughput by up to 20% or, in extreme cases resulting in the centrifuge pumps tripping out.

The only remedy to date has been shutting down the associated plant for time-consuming and expensive jetting'.

These maintenance shutdowns are typically required every six weeks, taking up to two days and costing over GBP2,000 a time.

In addition to these direct costs, the fatty deposits also have a negative impact on the Minworth energy bills, firstly because the sludge pumps have to work harder and, secondly, because restricted flow to the digesters reduces the amount of methane available to the award-winning Minworth sewage-to-energy plant.

During the maintenance shutdowns the sludge thickening facility is bypassed which has led to a reduction in gas production from the digestion plant.

This has a knock on effect in terms of loss of revenue as the site is unable to export surplus electricity to the national grid, thereby increasing the requirement for importing electricity.

Vine continues: 'The trial with Inditherm has been extremely impressive to date, with almost no fatty deposits observed in the two inspections since the heating jackets were installed in December 2005.

In addition to immediate and quantifiable benefits in the sludge routes, the Inditherm solution is also contributing to efficiency gains across the whole plant.

Further installations and monitoring will reveal quite how much we stand to gain in the long term.

Since the tests have only been completed on line 1 of 2 we are still having to jet clean line two every six weeks, as before'.

Inditherm's solution applies a safe, low voltage across a unique, patented carbon-based polymer to generate a uniform heat.

At Minworth this polymer is encased in heating pads which are strapped to the pipes and covered with conventional insulation and metal cladding.

Commenting on the success of the trials, Richard Harpum, CEO of Inditherm said, 'Although the Inditherm team were confident that we would see a significant reduction in fatty deposits, the trial results far exceeded even our most optimistic expectations, showing no build up at all.

Severn Trent shares our excitement both in terms of the reduced fat build-up and also the anticipated pay-back period of less than a year.

This latest application adds to our growing range of heating and insulation products for the utilities sector, including chemical dosing line heaters and thermal jackets for pipework and storage vessels.

As such, Inditherm is especially well positioned to help water companies respond to the efficiency challenges posed by the current AMP4 infrastructure programme.'

Centriquip has cut the cost of maintaining the decanter centrifuges at Scottish Power in Glasgow by exchanging the old stainless steel and tungsten discharge port liners with new ceramic ones.

Centriquip has cut the cost of maintaining the decanter centrifuges at Scottish Power in Glasgow by two-thirds by exchanging the old stainless steel and tungsten discharge port liners with new ceramic ones. The new liners last three times as long before they need changing. They're cheaper too! Scottish Power uses 12 Andritz-Guinard decanter centrifuges in continuous operation to dewater sewage sludge.

Each machine has 10 discharge ports for evacuating the solid phase from the machine.

The ports have sacrificial liners which, in common with most manufacturers, are made from tungsten in a stainless steel housing.

Until now these liners have worn quickly requiring the machine to be stripped for maintenance every 3 months.

The new liners from Centriquip, however, are made from a harder-wearing ceramic material.

They are half the cost of the tungsten liners and last three times as long.

Keith Burdon is the Maintenance Supervisor for Scottish Power.

In a recent interview he said that the new liners had made a significant saving in time and maintenance costs.

'We shut the machines down for routine checking every three months.

We use an endoscope to check the condition of the liners and strip the machines only if they need changing.

A strip down takes us a week.

The ceramic liners are lasting much better than the old ones so major maintenance is needed less often,' he said.

Centriquip is the largest UK manufacturer of decanter centrifuges and uses ceramic liners on all its new equipment.

The company also services and repairs any make of decanter and can supply ceramic discharge port liners for any make of machine.

Mixers and pumps made by Landia are helping a renewable energy operator sustain optimum production from its biogas plant.

Mixers and pumps made by Landia are helping a renewable energy operator sustain optimum production from its biogas plant. Domestic waste, straw, abattoir waste and sludge from wastewater treatment plants is first mixed by a Landia PODB-1 in a reception tank before being transferred to a biogas reactor by a no-nonsense Landia MPTK-1 chopper pump. The innovative knife system of the MPTK-1 ensures that solids cannot get into the pump and clog it up, so there is no downtime for the renewable energy company or its contractors.

Available with motors ranging from 0.55kW to 30kW, this highly efficient Landia Chopper Pump has a specially designed pump casing and impeller which protects it from impurities.

The new CQ7000 decanter from Centriquip meets the demands of the water industry for high throughput de-watering equipment.

The new CQ7000 decanter from Centriquip meets the demands of the water industry for high throughput dewatering equipment. The CQ7000 is new from Centriquip and is a development of the trusted CQ3000, CQ5000 and CQ6000 range. The new decanter has been developed specifically for the waste water and sewage market that requires the high throughput of 80 cubic metres/hour for dewatering and 120 cubic metres/hour for thickening offered by the CQ7000.

John Ball, Director of Centriquip, said that the benefits to the customer are those of cost and space saving.

'The CQ7000 doesn't take up much more space than the smaller machines but has a much greater throughput.

It is also less expensive, pro rata, than its predecessors'.

John also explained that companies using these high volume machines would do so only if the volumes being processed required multiple machines.

'Companies wouldn't have one large machine instead of two small ones as this reduces the operational flexibility,' he explained: 'But to have five CQ7000 machines instead of say ten CQ5000 makes lots of sense'.

Centriquip is the largest UK manufacturer of decanter centrifuges.

The company also has the ability to service and repair any make of decanter, often more efficiently, and at lower cost than the original supplier.