LIMEMILK
Safe Limemilk Pumping in Wastewater Treatment
How to optimise pH value pH value pH value regulation with a peristaltic pump
Reliable pH adjustment is a key process step in municipal water treatment plants. But how can highly abrasive lime milk with a high solids content be pumped safely and economically over the long term? And which pump technology reduces maintenance, energy consumption and safety risks in equal measure?
As a global specialist in handling complex media, NETZSCH Pumps & Systems offers tried-and-tested pump solutions for demanding applications in water and wastewater technology. We will show you how to reliably and efficiently dose limemilk with a high solids content.
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Challenges when pumping limemilk
Limemilk, based on calcium hydroxide, places high demands on the pump technology used. The medium is highly abrasive, has a solids content of around 30 percent and a pH value pH value pH value of around twelve. In addition, limemilk tends to sediment, which can lead to deposits, flow losses and unplanned downtime if unsuitable pumps are used. In addition to mechanical stress from abrasion, corrosive properties also negatively affect many conventional pumps. For operators, this means frequent maintenance, a short service life, and an increased risk of leaks when handling hazardous media.
Limitations of conventional shoe hose pumps
At a municipal wastewater treatment plant in the Midwestern United States, limemilk was used to raise the pH to meet state and federal quality requirements. Peristaltic pumps with shoes were used for this purpose. Although peristaltic pumps are generally suitable for applications like this, practical experience showed the existing design had significant disadvantages. The constant friction between the shoe and the hose led to high heat generation, severe hose wear and high lubricant requirements. In addition, the high starting and operating torques required oversized motors, which significantly increased energy consumption. Furthermore, changing the hose was extremely time-consuming and could only be done in confined spaces.
Reliable and energy-efficient limemilk dosing
In spring 2024, the plant operator decided to replace the existing pumps with PERIPRO® hose pumps chemical version. Peristaltic pumps from NETZSCH feature a modern XXL roller design and are specifically designed for abrasive and corrosive slurries, such as limemilk. Peristaltic pump technology relies on gentle displacement of the medium through an elastic hose. Large rollers compress the hose with minimal friction, significantly reducing mechanical stress from the slide shoe. The XXL roller design minimises friction between the roller and the hose, considerably reducing heat generation and extending the hose’s service life. At the same time, the low starting and operating torque allows the installation of smaller motors, reducing energy consumption by up to 30 percent compared to conventional shoe pumps. Since the PERIPRO® requires only a very small amount of lubricant, lubricant consumption is reduced by up to 90 percent, significantly reducing maintenance and ongoing operating costs. Another significant advantage is the pump’s open-side design, which allows quick and safe hose replacement even in confined spaces. As a result, maintenance downtime can be significantly reduced. In addition, the hose connection is fully enclosed within the pump housing, helping prevent leaks. This increases occupational safety, especially when handling harmful limemilk. The overall design of the PERIPRO® does not require any valves, seals, or stationary components that come into contact with the media. Any product leaks are completely contained within the pump housing and therefore pose no risk to personnel or the environment.
Since the PERIPRO® peristaltic pump was commissioned, the wastewater treatment plant has been able to significantly stabilise the limemilk dosing process. Moreover, a higher delivery volume is achieved, resulting in fewer compression cycles. This thereby increases the service life of the hose. At the same time, lubricant consumption has decreased significantly, and energy requirements have been reduced by a considerable amount compared to the previous shoe pump solution.
Contact the experts at NETZSCH Pumps & Systems to analyse your wastewater treatment application. We will be happy to assist you in designing a safe and economical pump solution.
PERIPRO® hose pump chemical version
