Magflow meters are non-contact instruments with no moving parts, requiring minimal maintenance. They feature a wide measuring range, a broad range of pipe sizes, and low power consumption. Their liners and electrodes can be selected or replaced according to specific measurement requirements, making them easy to use. Magflow meters can measure the flow of various conductive liquids and slurries, which makes electromagnetic flow measurement particularly well suited for industrial water, papermaking white water, and wastewater applications in the pulp and paper industry.
As a typical water-intensive and high-discharge industry, papermaking involves complex processes such as raw material preparation, pulping, bleaching, papermaking, chemical addition, and wastewater treatment. Throughout these processes, flow measurement instruments serve as core monitoring tools, not only ensuring process stability but also playing a critical role in energy savings, cost reduction, product quality improvement, and environmental compliance.
Application Scenarios of Magflow Meters in the Pulp and Paper Industry
Some typical application scenarios of magflow meters in papermaking are outlined below:
Pulping and Bleaching Sections
In chemical pulping, the accurate proportioning of cooking chemicals (such as sodium hydroxide and sodium sulfide) and additives directly affects fiber separation efficiency. With high accuracy (±0.5%), excellent corrosion resistance, and no pressure loss, electromagnetic flow meters are the preferred choice for chemical liquor flow monitoring.
During bleaching, the flow control of oxidizing agents such as hydrogen peroxide and chlorine dioxide requires fast dynamic response. Coriolis mass flow meters, which can measure mass flow in real time without being affected by changes in density or viscosity, achieve metering accuracy of ±0.1% in bleaching chemical dosing systems. This significantly improves brightness stability and reduces chemical consumption.
Coating and Ink Dosing Control
In paper coating and printing processes, magflow meters are used to monitor and control the dosing of coatings and inks. Real-time flow measurement ensures consistent coating weight and stable printing quality for every sheet of paper.
Cooling Water Flow Control
Large volumes of cooling water are required during paper production to cool equipment and processes. Electromagnetic flow meters are installed in cooling water pipelines to accurately measure flow rates and ensure proper operation of cooling systems, preventing equipment overheating.
Wastewater Treatment Flow Monitoring
Papermaking generates large amounts of wastewater containing organic matter and other pollutants. Magflow meters are widely used in wastewater treatment systems to monitor wastewater flow and concentration in real time. This helps ensure effective treatment performance, control pollutant discharge levels, and protect the environment.
Energy Management and Conservation
Magflow meters provide accurate flow data for energy management and conservation. By monitoring and controlling flow rates, paper mills can optimize energy consumption, reduce waste of both energy and water, improve production efficiency, and enhance environmental sustainability.
Application Case for Magflow Meters
In the papermaking industry, the media requiring flow measurement are mainly classified into slurries (such as wood pulp and bamboo pulp) and black liquor. In 2023, a well-known paper mill in Guangxi contacted our company seeking a solution for black liquor flow measurement. Their black liquor measurement involved two process stages:
Evaporation section black liquor: medium temperature of 120 °C and concentration below 3%.
Digestion (cooking) section black liquor: medium temperature of 170 °C and concentration below 3%.
The customer required stable and accurate flow measurement, good agreement with level measurement, display fluctuation of less than 2%, and a service life of more than three years.
For the black liquor in the evaporation section, our company recommended the Aimag-C electromagnetic flow meter with a remote transmitter, PTFE liner, and 316L stainless steel electrodes. For the black liquor in the digestion section, considering the high-temperature characteristics, we customized a thickened PTFE liner and applied thermal insulation and heat dissipation treatments to the excitation coil and magnetic circuit system inside the sensor.
For the electrodes, spherical 316L stainless steel electrodes were used. To prevent poor electrode insulation caused by liner thermal expansion, a specially designed electrode locking structure was adopted. After reviewing our solution, the customer proceeded with the purchase. The meters are currently operating stably with accurate measurement results.
