NOV Mono solves sludge transfer problem for German wastewater plant.
NOV Mono has helped solve an ongoing maintenance problem for a major German wastewater treatment plant with the installation of an EZstrip™ TR Muncher.® The Mono Muncher has dramatically reduced the number of pipeline blockages occurring at the Käranlage Jagersfreude plant and so helped minimize both downtime and maintenance costs.
Based in Manchester, England, NOV Mono is Europe’s leading designer and manufacturer of pumps, parts, grinders, screens, and packaged systems, with products including maintain-in-place progressing cavity pumps, heavy and light duty industrial transfer pumps, widethroat pumps, hygienic pumps, dosing pumps, solar pumps, as well as grinders and screens.Therefore, a partnership with the Käranlage Jagersfreude plant—the largest facility of its kind in the Saarbrücken area—was a natural fit.
For a plant the size of Käranlage Jagersfreude, problems in one part of the system can lead to a domino effect down the line. One of the plant operators’ chief concerns is blockages in the line from the abundant and dense sludge the plant processes every day. Macerating pumps are the main tool to combat this problem, but the plant’s previous macerator was not up to the job.
The customer’s previous macerator had been experiencing increasingly frequent blockages—often one each day—due to the 8 to 12 percent dried solids and fiber content of the raw sludge it was handling. The process of repeated de-ragging was both time consuming and expensive, so an alternative solution was sought. The Mono EZstrip™ TR Muncher, however was designed specifically to provide efficient maceration of abrasive sludges in this type of application. The Muncher’s layback cutter shafts are set at an angle to the incoming sludge flow, making it extremely effective in capturing and macerating solids held in the flow.
For the Käranlage Jagersfreude plant, this helped to increase protection for pumps and other equipment further along the process line by minimizing wear and so reducing the needs for spares to be held. If a rejection cycle is necessary, the Muncher can drop the object into the built-in trap which is set below the cutter stacks to prevent damage occurring. The waste trap features a large-diameter access port which allows for easy removal of debris, cleaning, and flushing.

The complete drive, gearbox, and cutter assembly can be removed from the Muncher’s casing, without disturbing the pipework “This makes any maintenance activities much quicker to complete and it also reduces the downtime and the associated costs,” explains Jagersfreude plant wastewater manager Ewald Stresser. “The Mono Muncher handles around 1060 cubic feet (30 cubic meters) per hour of raw sludge and has worked very efficiently since it was installed, but it is reassuring to know that if a blockage does occur we can remove it far more quickly and easily than we could previously.”
The EZstrip™ TR Muncher is latest version of NOV Mono’s “maintenance friendly” Muncher® range of grinders. From the initial concept through final manufacture, the real-world concerns of water and wastewater treatment plant operators were incorporated into the pump design. For example, instead of producing one uniform macerator, the Muncher series offers a choice of cutter materials and thickness, which allows plant operators the flexibility of matching their power needs with their energy consumption limitations. Finding the right fit for a specific plant’s needs should prevent unnecessary overloading and the related maintenance expenses in the long term, while also saving operation expenses immediately.
The pump’s easy assembly and disassembly is another influence of the “maintenance friendly” philosophy. When repairs or deragging is required, a full access port on the pump allows for quick inspection, all while cutters and spacers maintain in place. This also allows for an easily removed cutter stack and eliminates any need to disconnect pipework. Since there are no special tools required, maintenance downtime is greatly reduced—a boon to maintenance personnel in two ways. For one, this means increased labor savings and, for another benefit, fewer hours spent on cumbersome repairs means workers are less fatigued and less likely to fall victim to on-the-job accidents. From a management, labor, and mechanical standpoint, operational parameters are unaffected.
The ETOS cutters in the Mono EZstrip™ TR Muncher provide effective maceration, as the cutter shafts operate at differential speeds to exert a tearing action on the solids. A cantilever shaft design eliminates the need for bottom bearings and seals which significantly reduces wearing components, while low cutter tip speeds reduce wear.
A low power consumption rating further cuts the TR Muncher’s operating costs. Each Muncher is supplied with a programmable logic controller to protect against overload damage, and they can be supplied to comply with the ATEX Directive 94/9/EC.

This latest success confirms NOV Mono’s commitment to increasing its support for the German market. There is a wide range of potential applications for our EZstrip™ progressing cavity pumps in the German wastewater market, and the EZstrip™ Muncher offers a natural complement to those pumping solutions. All EZstrip™ products can be maintained in place, without the need to disconnect or remove any pipework.
Additionally, NOV Mono can provide Mono Universal Parts, which are engineered and manufactured by Mono Pumps and are suitable as spare parts for many other brands of PC pumps. Comprehensive stocks enable us to offer fast turnaround to help reduce equipment downtime. Mono Pumps has a wide range of integrated solutions for the municipal waste water market. ■
Nancy Lauseng is the marketing manager for Jet Edge, a global designer and manufacturer of waterjet systems for precision cutting, surface preparation and coating removal. She can be reached at 763.497.8726 or For more information about Jet Edge, visit, or call 800.JET.EDGE (538.3343).
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