Pumps & Valves

A new aeration system has rescued a paper mill in El Salvador that was on the brink of $M fines for causing major odor issues.

Changes to environmental regulations had put the company into a crisis situation, despite the fact that they had already installed four 30HP surface aerators in their aeration tank in an attempt to quell the increasingly bad odor problems.

With the authorities set to take serious punitive measures, the paper mill called in leading wastewater treatment business, Black Waters to see if they could bring about a solution.

“This was a major challenge,” said Roberto Escalante, Principal of Black Waters.

“Nobody in our industry particularly relishes working with a slanted floor (!) rectangular tank (1,000m³), but I can tell you that the twisted face of the paper mill’s CEO was in far more pain than mine!

“It was primitive; in a bad way, resulting in the possibility of substantial fines that caught the paper mill completely off guard,” he added.

“The odors were awful, so we went straight into action with a sludge sampler to see what was going on, in order to establish a proper profile.”

Across the 75.4’ (23m) length tank, which has a shallow end at 6.2’ (1.87m) and a deep end of 13’ (4m), Roberto found that only five of the one-meter sections were free from sediment. The rest ranged from 0.8” to as much as 18” of sediment, varying from light brown towards the shallow end to thick dark gray at the deep end.

“No wonder it stank so much,” added Roberto.

“At the deep end it was septic, because the surface aerators couldn’t mix the tank comprehensively. The slanted tank had become a biological reactor, but with the buildup of sediment, there just wasn’t enough oxygen to allow the bugs to do their job properly. They couldn’t ‘breathe’ and so would die. It was nasty.”

‘Dire situation very much needed some oxygen’

He continued: “All well and good having some mixing, but this dire situation very much needed some oxygen. The wastewater from the paper, which in this case was from a process manufacturing tissue paper, is surprisingly abrasive. Surface aerators can make it appear as if there is lots happening, but underneath the surface it can be a totally different story. In a fairly short space of time, foul odors will soon tell you that something is seriously wrong!”

With a potential $M lawsuit for violations on the horizon, Black Water urgently sought a rapid but long-lasting solution, consulting with contacts in the US and beyond to see what might be available.

“With a slanted tank,” added Roberto, “they all said they wouldn’t blame me if I walked away. But we are engineers of course, so we’ll always want to find an answer, even in this case, where it possibly couldn’t be a perfect world solution. They told me I was crazy taking it on, but I already knew that. At least I’ll never be as crazy as the person who thought that it was such a good idea to design a slanted-floor rectangular tank for a paper mill’s wastewater!  Additionally, the tank was divided into two halves by a concrete wall, so we had to cut eight-inch holes across it to try to even out the flow distribution.”

‘Simultaneously mixing and aerating’

The recommended solution certainly wasn’t the cheapest, but it came in the form of a simple design, combining a proven chopper pump with a venturi nozzle; the Landia AirJet.  Simultaneously mixing and aerating, this system effectively keeps wastewater fresh; economically delivering dissolved oxygen to provide complete aeration.

The next challenge for Black Water was how to incorporate what would be six of the new Landia AirJets onto both sides of the tank.

“Landia helped us calculate the best positioning,” said Roberto, “and I was really pleased that their vastly experienced Aftermarket Manager, Ken Jacobs came over from the US to help ensure that the installation went smoothly. The Landia AirJets had to be installed with middle guideline poles that had to be embedded in specially built concrete blocks. This allowed the aerators to be then slid to the bottom of the basin. The Landia Chopper Pumps that are part of the AirJet system do a great job, and are proving very reliable. Everything is fine now. Thank goodness those horrible odors are no more!”

www.black-waters.com

www.landia.world.com

In industrial environments, pumps and valves are not just components—they are critical assets. Whether in manufacturing, chemical processing, utilities, or energy sectors, these devices keep systems flowing, regulate pressure, and maintain safety. For maintenance professionals, they represent a significant share of both routine and reactive workloads.

From a maintenance standpoint, equipment reliability begins long before the first service interval—it starts with selecting the right pump or valve for the job. Misapplied components often become repeat offenders on the maintenance schedule. Understanding the operational demands—fluid type, pressure range, temperature, and flow variability—is essential in ensuring long-term reliability and reduced total cost of ownership.

For pumps, seal wear, cavitation, bearing failures, and misalignment are among the most frequent issues encountered. In many facilities, centrifugal pumps are the workhorses, but without proper installation and regular monitoring, they can be vulnerable to premature wear.

Valves, on the other hand, often suffer from seat wear, stem corrosion, actuator failure, or clogging—especially in high-debris or chemically aggressive environments. Actuated valves bring their own set of challenges, from motor or air supply faults to control signal miscommunication.Traditionally, many sites have relied on preventive maintenance schedules, performing periodic inspections and overhauls based on calendar intervals. While this is a step up from reactive maintenance, it's often not optimized to the actual usage or condition of the equipment.

Today, facilities are shifting toward predictive maintenance strategies, using sensors and condition monitoring to track vibration, pressure, flow, and temperature data in real time. This allows maintenance teams to intervene only when necessary, minimizing downtime and extending equipment life.Simple practices go a long way. Regular lubrication of pump bearings, shaft alignment, and seal inspections can drastically reduce failure rates. For valves, ensuring correct calibration and stroke testing helps maintain accuracy and control integrity.

Documenting these tasks within a Computerized Maintenance Management System (CMMS) allows teams to track component history, flag recurring problems, and plan resources more effectively.

Another smart move for maintenance planners is the standardization of pump and valve types across facilities. This simplifies training, reduces the variety of spare parts needed, and shortens repair time.

Maintaining a strategic inventory of seals, gaskets, actuators, and wear parts ensures rapid response when breakdowns occur—especially for mission-critical assets.

No matter how advanced the technology, well-trained maintenance technicians remain the cornerstone of reliability. Understanding failure modes, interpreting performance data, and knowing how to restore components quickly and safely makes all the difference.

In the world of industrial maintenance, pumps and valves deserve focused attention. They are integral to uptime, process efficiency, and safety. With the right strategies—from predictive monitoring to proactive parts management—maintenance teams can keep these essential assets running smoothly and cost-effectively.

Standards are very high at the acclaimed Urbana & Champaign Sanitary District (UCSD). Very High!

Offering a one-year guarantee on your equipment? Think again.

When the team at this Illinois treatment facility looked to upgrade the pumps on three of its anaerobic digesters, a lifetime of around 20 years was expected.

Almost eight years in, and the pumps that were installed on the 500,000-gallon digesters, are, according to Justin Profancik, Director of Operations at UCSD, ‘very dependable, reliable and durable’.

Situated approximately 140 miles south of Chicago, UCSD’s digesters were built separately over a period of years at its Northeast Treatment Plant (NEP), which opened in 1924 (UCSD’s Southwest Treatment Plant opened in 1968). In 2016, it was time for an upgrade, especially as the existing pumps were clogging up more or less on a quarterly basis.

“The old units had done a pretty good job,” said Justin Profancik, “but weren’t Chopper Pumps (*invented by Landia in 1950), so the solids, rags and grit would gradually accumulate, causing them to clog. We then had to take them apart and 

clean them out, so there was a lot more maintenance involved then, compared to now.

‘Maintenance department really likes the design’

“When we’ve inspected the Landia pumps (each 7.8HP) over the past seven years, there hasn’t really been anything of any major significance to worry about. On the Landia Chopper Pumps’ external knife system, you can change the blades easily. Our maintenance department really likes the design.”

Created over a century ago by voter petition, UCSD is a municipal body that provides wastewater treatment for properties in the Cities of Urbana and Champaign, as well as the villages of Bondville and Savoy. It also serves the University of Illinois (56,000 students). It is not a part of any other local, municipal, county, township or state government. Today, it employs 50 people, including 10 operation staff.

At UCSD’s Northeast Treatment Plant (NEP), solids management facilities include gravity belt thickeners to thicken waste activated sludge (WAS); a sludge receiving station that receives thickened waste activated sludge (TWAS) from the UCSD Southwest Plant (SWP), industrial WAS, high strength waste (HSW) from grease-hauling trucks and a small amount of food waste from a Hershey’s (chocolate) truck wash and the University of Illinois. There is also a tank that blends sludge 

from the receiving station with NEP TWAS and primary clarifiers; four anaerobic digesters (three of which are now served by the Landia Chopper Pumps); a digested sludge storage tank; and three centrifuges to dewater the digested sludge. The dewatered biosolids, which meet Class B biosolids requirements, are land-applied as soil amendment to agricultural fields.

Digester gas produced in the anaerobic digesters is used in combined heat and power (CHP) engines to cogenerate electricity and heat for the NEP, as well as export electricity to the grid.

‘Protecting downstream equipment’

“We call the Landia units our recirculation pumps,” continued Justin Profancik, “but (stored in the basement of our AD complex) they are part of the heating cycle, effectively working as recirculation pumps through our heat exchangers to heat the digesters. We used to have to clean the heat exchangers out about once per month, but with the Landia Chopper Pumps continuously chopping and reducing the particle sizes of the sludge, this is only required about once per quarter – and in those quarters, a lot of times, we're usually not really finding anything, even in the small veins of the heat exchanger. It 

shows in this case that top quality pumps play a big part in protecting downstream equipment.”

Since the installation of the Landia Chopper Pumps for the UCSD digesters, gas production has increased; hitting a record high of 400,000 cubic feet per day. Typically, though, it is around an average of 190,000.

‘Hershey truck wash’

Justin Profancik added: “Although the food waste we take in from the Hershey truck wash is less than one per cent of our feedstock, we can see the difference in gas production immediately.”

As a District that likes to use its money very effectively and efficiently, UCSD more than did its research into the new pumps that it needed for its digesters. This culminated in visiting Landia’s manufacturing facility in Lem, Denmark, which came about through the Water Technology Alliance (WTA), an outreach program to share valuable water technology solutions between the North American and Danish water sectors. Wade Lagle, previous Director of Operations at UCSD (who has over 40 years’ experience in wastewater treatment), explained:

“Seeing where and how the pumps were made gave us very positive reassurance,” he said. “The quality control and cleanliness of the facility was second to none. It is a wonderful 

production facility. We could see that the Landia Chopper Pump is very well designed, and that it would be a very good fit for our digesters, low on maintenance, highly effective, and with a long lifetime. Total cost of ownership is very important to us.”

Justin Profancik continued: “Installation was very straightforward, and because the pumps haven’t had any major issues, we’ve not had to make that much contact with Landia, but when we do, they’re always there with help and advice, wanting to ensure that everything is right. We’ve had really great success with the Landia Chopper Pumps.”

Plant setups need well-maintained pumps and valves. They need to handle fluids, pressure, and flow control smoothly for the sake of a productive operation.

The only way plant engineers can ensure that the pumps and valves operate in tip-top condition is through stringent monitoring. However, the job won't be as easy without PCB-based data loggers.

PCB (printed circuit board) data loggers are small but powerful tools that keep track of pump and valve health. The best ones provide insights that will reduce everyone's headaches, particularly when dealing with maintenance.

PCB-Based Data Loggers

Designed to monitor equipment performance, PCB-based data loggers are composed of printed circuit boards and sensors. The use of multi-layer PCB allows a compact build while serving as the core of the system.

These devices process data from sensors in real time. They keep track of the pressure, temperature, vibration, and flow rate. It's the ultimate machine that helps plant managers keep an eye on how their pumps and valves are holding up.

PCB-based loggers are also precise and versatile. They collect data continuously, which means they monitor the performance and raise alarms early before they cause real problems. This level of insight is critical for preventing loss.

What Data Do PCB-Based Loggers Capture?

PCB-based data loggers track key performance metrics, which are as follows:

• Pressure and Flow Rates: Fluctuations in pressure or inconsistent flow indicate blockages or leaks.
• Temperature: PCB-based loggers also check rising temperatures that indicate friction, poor lubrication, and other mechanical issues.
• Vibration Levels: High or unusual vibrations are often the first sign of misalignment or imbalance.
• Operating Cycles: Tracking how often pumps and valves cycle on and off helps gauge overall efficiency.
•  

PCB-based data loggers monitor these factors, ultimately giving plant engineers a clearer picture of equipment performance and whether it needs attention.

Why Use Data Loggers for Monitoring?

Manually checking pumps and valves isn't cost-efficient. Plant managers use data loggers to make monitoring seamless and accurate. Here's why they're worth it:

1. Continuous Monitoring: Loggers work 24/7. This ensures you never miss a potential issue.
2. Early Problem Detection: Catching anomalies early prevents costly breakdowns.
3. Data-Driven Maintenance: Real-time data lets you schedule maintenance when it's actually needed. There is no need to guess when to call the crew.
4. Improved Efficiency: With actionable insights, you can optimize operations and reduce energy use.

Integrating PCB-Based Data Loggers

Surprisingly, installing loggers to plant systems is incredibly easy. Most of the units are designed to attach directly to pumps or valves.

Once connected, the sensors feed data to the PCB. From hereon, data collection begins. Some loggers even sync with your plant's monitoring systems, letting you access data through dashboards or alerts.

When setting them up, plant engineers must configure the logger correctly. Make sure you're tracking the right metrics and setting thresholds for alerts. This way, you'll know when something is off without constantly checking the system.

PCB-based data loggers save plant engineers from a lot of guesswork. This technology provides a reliable way to track performance and spot issues before they blow up. It's all about working smarter, not harder, and these tools are a step in the right direction.

Following an extensive upgrade of its reception tank and digester mixing system, Eco Verde Energy (EVE) has put a once troublesome Anaerobic Digestion (AD)+ plant firmly back on track with encouraging new biogas yields.

At Holton* in Suffolk, England, which receives around 65% of its feedstock from the adjacent Bernard Matthews poultry facility, the AD plant, under a series of different operators, had seen biogas production drop significantly, and eventually to a complete halt for a much-needed overhaul.

Initially, the primary digester (2700m³) was drained down, discovering, as expected, faults with the mixers, but also a broken stanchion. Later, further inspections revealed that there was damage to the roof of the digester, so the decision was taken to postpone operations for a complete maintenance revamp.

“The mixers that were sold in as part of the biogas package were never going to last in the long-term,” said Eco Verde’s Site Manager at Holton, Kris Martin.

“It is hard to understand a design that doesn’t allow equipment to be looked after! The mixers couldn’t be lifted out of the tank for even the most basic of service tasks such as an oil change and cleaning the propellers.”

He added: “At one point, the site was being run remotely, but it has now benefitted from a complete review of operations. When we shut down for the maintenance overhaul, trying to get shipshape became more challenging, due to some suppliers not being able to assist; either unable to provide equipment quick enough for our needs, or did not seem to have a deep understanding of the industry. Either way, the essential assistance we required was not readily available. We couldn’t for example, get anyone to look at the feed-in module (which is a jacketed tank to provide heat) we have between the reception tank and the digesters. The previous chopping pump had failed because of the high temperatures, so again, it wasn’t specified properly. There can be a huge difference in supplying equipment in 304 stainless steel compared to 316. For a biogas process with food waste, compromising is only going to lead to problems.  This has been the classic case of a package plant being sold on price rather than quality.”

Matters took a significant turn for the better though when Kris made contact with Landia, about whom he’d heard good reports.

‘Clearly wanted to try and understand how a solution could be found’

He continued: “They’re a pump and mixer company, and there are plenty of those,” he said, “but unlike some others, they actually listened and clearly wanted to try and understand how a solution could be found. As soon as they first came to the site, there was a good vibe. Linking up the mixing operation from the reception tank, through the feeding module, and then on to the digesters, and finally through to the pasteurisers, wasn’t going to be easy, but rather than just try and sell us equipment, Landia were keen to find a way to help make the Holton plant perform as it should.”

New submersible mixers (5.5kW) from Landia have been installed for the reception tank, which unlike the previous units, can be easily lifted up on a crimped rail system for inspection to remove any plastics and perform standard maintenance such as oil changes.

For the feeding module, which is batch-fed from the reception tank, a Landia Chopper Pump (invented by the company in 1950) has replaced the failed unit. The unique external knife system (combined with the addition of a new shredder propeller) ensures that particles are continuously reduced in size, and that solids cannot enter the pump’s casing.

The primary digester was first upgraded to replace the failed units with Landia mixers. By utilising a pre-existing hatch system that provides easy access, these new 18.5kW mixers were installed with minimal disruption to the biogas process, and can likewise be easily serviced without causing downtime.

The secondary digester is now served with a system that comprises the proven Landia chopper pump, fitted with venturi nozzles to provide truly comprehensive mixing. When the primary digester meets the right level, the feedstock is automatically transferred to the secondary digester. The simple, but highly effective combination of submersible mixers, chopper pumps, and the venturi nozzles work to constantly recirculate the mixture of liquid and gas, even though it only typically has to run in 10-minute intervals, rather than mixers at many plants that run flat-out 24/7.

At the end of the process, in order to meet the legal requirements of a feedstock that contains animal bi-products, there are now two (25m³) Landia pasteuisers, which heat the final effluent to the required temperature of 70 degrees centigrade. The pasteurisers are supplied as complete processing units (tank, chopper pump, and controls), to break down the food waste effluent and any remaining solids. Each tank from Landia is made with a double stainless-steel tank wall that acts as a heating jacket. From here, heat is transferred by circulating hot water, meaning that a heat exchanger is not always required. Post-pasteurisation, with the maximum possible amount of gas extracted, the final digestate from Holton makes a first-class, nutrient-rich fertiliser.

‘Nothing on this site is now off-the-shelf’

Kris Martin added: “The more Landia and I worked together, the more we had a focal point. Although they do provide some guide rails and pipework, it’s not their main business, but when looking at how we could transfer everything from the start of the process, right through to the pasteurisers, it made sense for Landia to include it as part of their service, rather than me having to bring in another supplier. They did a top-quality job in putting all the extensive pipework together. It’s very impressive and we’re all proud of it. Nothing on this site is now off-the-shelf. Paul Broadhurst (from Landia) and I have put this all together step-by-step. It’s not been easy, but we’ve worked through it with a very healthy rapport and that all-important common goal of wanting something to work and work well for the long-term. It’s a world away from the daily hassles that we had previously. Paul’s attitude to whatever we ask is ‘we’ll sort it out’, and I know he and Landia will, because they value us as a customer and care about the plant’s success.”

In addition to its primary feed (which is first treated by a DAF -Dissolved Air Flotation) piped in from the Bernard Matthews poultry facility’s treatment plant, EVE’s Holton site also receives effluent from the local Adnams brewery and distillery, plus various fats and oils from nearby food processing plants. This variety of intake then takes very careful managing to maintain a steady feed for the now, much loved biogas plant.

Kris Martin continued: “With the Landia submersible mixers at the front end, we’ve gradually developed a constant, homogenous feed, which provides excellent stability for the remainder of the process and our drive to maximise biogas yields. The consistency we have means happy bugs, because otherwise, too much of one intake at one time can cause foaming. That’s not an issue at this site any more.”

At 1.1MW, the new-look Holton biogas plant (which now has two CHP engines and additional gas storage), can provide most of Bernard Matthews' 1.4MW energy needs, with a grid connection in place for times if/when the poultry facility is on shutdown.

‘Low energy consumption

and maximum biogas yields’

Kris commented: “The investment here safeguards the future, with plans for a lagoon to be built and to have PAS 110. With Landia’s help, it means that we’ll be in good shape with low maintenance costs, low energy consumption and maximum biogas yields, which of course means profit – not to mention the fact that we do something great by making renewable energy from waste.

“Having to shutdown and clean out a couple of digesters creates downtime of almost three weeks; costing in the region of £150,000. We’re pleased of course to have now sorted out all the problems; turning everything around so that instead of having put out fires, we can finally be proactive and concentrate on making gas, rather than having to react to all the problems on site. The initial issues were made all the worse by having equipment that you couldn’t work on without having to shut the plant down! A design that effectively traps mixers inside the tank without access is ridiculous.

“We now have a proper maintenance schedule in place, and unlike in the past, no problems or delays in the availability and delivery of parts. If we order before lunchtime, Landia deliver the next day. During installation, there were also never any problems with the paperwork and permits from Landia; progress emails, and all the necessary RAMS (risk assessment and method statement) and proof of qualification were in place so that the work was seamless, with no delays. This differs significantly from others who simply aim to provide a product, without considering how it integrates into our process.

“Site managers can overcome all sorts of challenges, but aren’t necessarily engineers. You need calculations. You need experts to answer your questions to complete the jigsaw puzzle. No two plants are the same. It is reasonable to expect seamless support from the companies that provide equipment, but often, you find yourself navigating through various departments – from quotations to finance, engineers, and a loosely termed ‘support team.’  Having to repeatedly explain your requirements can be very frustrating and time-consuming. It is always easier to work with those who have been to a biogas plant, and who aren’t worried about getting their hands dirty. It’s been a long journey to get where we are, but we now have peace of mind with a plant that is performing very well and with fine-tuning, will get even better. It shows exactly what can be achieved with the right people, the right equipment, and a belief in our industry.”

For a fast-growing company that makes machines for the post-harvest processing of vegetables, Hayley Group is set to provide two new Landia Chopper Pumps that have special external shredders.

Originally developed to deal with difficult wastewater solids in the fish processing industry, the Landia shredder-propeller design has now proved its capability in handling troublesome stringy material such as carrot tops, that typically cause problems for standard pumps.

Speaking for Hayley Group, the leading nationwide engineering component supplier (who also supply bearing and pneumatic products to the machinery manufacturer), Daniel Moulding, Assistant Manager, said:

“The Landia Chopper Pumps work extremely well for our customers in numerous applications. In this particular challenge, the specialist machinery company asked us for help, because their existing pumps struggled with the fibrous and gritty material that is an inevitable part of the wastewater process with vegetables.

“This latest purchase of two new Landia Chopper Pumps follows orders for five units that were successfully introduced at various locations during 2023.

“Landia have been very helpful indeed in working with us to understand our customer’s needs; adapting the shredder-propeller so that there is no longer any downtime on the processing lines, which is a huge benefit.”

Howard Burton, Technical Sales Engineer for Landia, added:

“For certain effluents with difficult solids, the pre-cutting shredder-propeller adds another important chopping stage; continuously reducing particle size and keeping the process running efficiently.”

Daniel Moulding from Hayley Group, continued: “In addition to providing such an effective, reliable solution, Landia also give us fast and efficient back-up whenever we need it.

“When our customer first used the Landia Chopper Pump, they said they’d never go back to the previous type of units. Another eight pumps later, we and they are very happy with the positive outcome, as are the end-users of the equipment.”

www.hayley-group.co.uk

www.landiaworld.com

Northern Ireland’s Agri-Food and Biosciences Institute (AFBI) has made a significant breakthrough with its research into on-farm biogas production by introducing a new digester mixing system.

At Hillsborough, one of seven AFBI sites that provide scientific research and services to government, non-governmental and commercial organisations, the retrofit of the AD plant’s main digester has improved biogas yields by 15-25%.

At what was the first biogas plant of its type in Northern Ireland, the cow slurry from the site’s 300-strong dairy herd is co-digested with grass silage produced on the research farm, to produce biogas which is combusted in a CHP engine providing heat and electricity for the site.

The new mixing system ensured that fresh feedstock was being better mixed in the main digestion tank and was not discharged too early, as witnessed by higher discharge temperature than that observed from the old mixing system.

Dr Gary Lyons from the Agri-Environment Branch at AFBI, said: “The original mixing system, installed when the plant was built, worked well for a number of years, but eventually a build-up of sludge in the bottom of the primary and secondary digestion tanks meant that we were getting poor digestate mixing. This impacted biogas production and the level of methane in the biogas. We decided that we needed to shut the system down, clear the sludge from the tanks, and retrofit a new mixing system on to the main digestion tank, which would not give us issues with sludge build-up in the future.”

‘A robust mixing system is critical’

He added: “At AFBI, we understand that busy farmers have more than enough to do, without having to constantly repair and maintain their biogas plant, so we’ve been able to see first-hand that a robust mixing system is critical. One that doesn’t have any wear parts on the inside of the tank will prevent the big headache of downtime.”

The new mixing system in question is a simple, but highly effective one. Externally-mounted, a Chopper Pump (invented by Landia in 1950) with venturi nozzles. No working at height. No working in the gas zone. And no costly downtime for servicing.

“There’s more to it than that of course,” continued Gary. The Landia GasMix provides the dual benefit of both hydraulic and biogas mixing in one system, which was appealing to the AFBI team. We’re not a commercial plant, but our role is to explore all of the possible benefits for farmers. This means not only maximising the amount of clean energy that can be produced, but how to achieve that with the minimum amount of energy that goes in.

‘More gas and also better quality gas’

“When we were just using slurry as a feedstock, the Landia mixers increased our output from 300 cubic metres of biogas per day of dry solids to typically 360, and as high as 400. I’m a sceptic by nature, but the results were there right in front of us with our readings; more gas and also better quality gas, with the Landia GasMix system working away without any problems, continuously reducing the particle size of the feedstock.

“Over time, only two of the 18 lines on the old mixing system hadn’t blocked. We knew we had to look for a lower maintenance alternative.”

Gary and his team’s search saw them consult with the first biogas plant of its type in the Republic of Ireland, where in County Limerick, impressive performance numbers were being reported at the site owned and operated by Greengas.

I spoke with David McDonnell at Greengas,” said Gary. “He told me that his plant was benefiting from having Landia mixers. I also looked hard at the Danish Biogas Association’s advice on the use of venturi nozzles for digester mixing at AD plants. This led to us working with DPS (part of the EPS Group) of Bangor (who supply Landia equipment in Northern Ireland and the Republic of Ireland) to help with their knowledge and experience

“In this situation, throwing more power at the process isn’t the answer. We’ve also understood that dwell times are very important, which takes convincing for some, but through careful fine-tuning, we don’t have to run the Landia mixers flat out to optimise biogas yields; just in 10-minute cycles, so only 30 minutes each hour. We need to experiment more with dwell times to hit the sweet spot of minimal mixing for maximum plant performance.

“We have had no problems with digestate mixing whatsoever since installing the Landia digester mixing system. By increasing the surface area of the feed with truly comprehensive mixing of the tank, the bacteria get to work much quicker. I do like the fact that the system incorporates biogas recirculation, and we do not appear to have solids settlement issues.

“As a scientific research centre, we’ve experienced the good, the bad and the ugly of AD, which should help farmers avoid the downside of those mixing systems that can only be retrieved by having to laboriously drain down the tank and then have to start the whole process from scratch. We won’t be doing that again.

“Following the increase in biogas production and methane content that we saw with mono-digestion of slurry as the feedstock, it will be very interesting in time to collate the data from the co-digestion of slurry and grass silage.”

www.landiaworld.com

For pre-treatment tanks at a wastewater facility in Indonesia, Landia is supplying 12 of its digester mixing systems.

Part of a major Bio Production Plant in Java, the facility converts grass materials into biodegradable bags, with the excess matter utilised to produce biogas in six 4,000m³ rectangular concrete tanks.

To accelerate the installation, Landia is sending the pipework of its externally-mounted systems in self-assembly sets, with an appointed engineer to supervise the set-up. At the heart of the system is the Chopper Pump (invented by Landia in 1950), plus venturi nozzles, which will provide comprehensive mixing of the tanks, so that no crust forms on the surface of the liquid.

Fergus Clark, who heads up the Asia-Pacific region for Landia, said:

"This is a very important new order, which underlines the effectiveness of our digester mixing system and the unrivalled reputation it has for maximising biogas yields.  Operators also like the fact that it is so reliable, and that everything is easily accessible on the outside of the tank - with no working at height. Unlike some systems, there is no downtime or very costly emptying of the tank for servicing or repair."

www.landia.com

Burdened with cumbersome maintenance, expensive spare parts and very high energy costs, a wastewater treatment plant has replaced its multi-phase eccentric screw pumps with new Rotary Lobe pumps, made by Börger.

Installed for a chamber filter press, the space-saving Börger pumps have been supplied as a twin-pack unit; two identical Rotary Lobe Pumps, which are operated in series. Each Börger rotary lobe pump has its own frequency converter that allows speeds to be individually regulated.

When feeding the chamber filter press, operators at the wastewater treatment plant now have a choice between two phases - the pre-fill phase and the pressurized phase. During the pre-fill phase, large quantities of sludge are pumped at high speed into the chamber filter press to fill up its chamber.

As the solids in the sludge gather in front of the filter screens, the increasing filling level of the chamber increases the counter pressure in the chamber filter press. Using the frequency converter, the speed of the Börger pumps is then reduced accordingly.

In addition to improving the output and efficiency of the application, the new Rotary Lobe pumps have drastically reduced energy costs, and are also far easier to service with their easy access, Maintenance-In-Place design.

Borger UK

01902 798 977

www.boerger.com

This email address is being protected from spambots. You need JavaScript enabled to view it.

A rotary lobe pump made by Börger has helped solve a wastewater processing problem at a textile manufacturer.

Taking effluent from the bleaching process into a storage tank, the Börger pump has to contend with significant fibrous material that also contains elements of hydrogen peroxide and caustic soda.

When the defined fill level of the wastewater has been reached in the collection tank, the Börger rotary lobe pump automatically conveys the liquid in measured amounts from the collecting tank into the sewage system.

Made of Duplex stainless steel and equipped with a maintenance-free mechanical seal, the compact Börger rotary lobe pump is very easy to service, requiring only basic tools.

Borger UK

01902 798 977

www.boerger.com

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