How Does Liquid Measurement Work in Paper Mills?

The paper manufacturing industry depends on precise liquid measurement and control at every stage of production. From the earliest wood chip processing to final coating, accurate monitoring of levels and flow rates is essential for product quality, process efficiency and avoiding costly disruptions.

Applications Engineering is the sole UK and Ireland stockist and supplier of Kytola flow meters and measurement devices. Kytola is a recognised name in liquid and flow measurement, so here’s how these systems work and how paper mills can select the right equipment for their needs.

The role of liquid measurement

Paper mills handle a wide range of liquids at multiple points in the process, each requiring reliable measurement and monitoring. Examples include:

• Papermaking: level meters for pulp in headboxes, storage tanks and pulpers

• Stock preparation: level monitoring in stock chests and tanks

• Chemical recovery: liquor level measurement in tanks

• Coating and bleaching: monitoring coating and bleaching chemical levels

• De-inking: checking pulp stock levels in flotation cells and tankers

Maintaining precise levels ensures a steady supply of quality material to the paper machine and consistent finished products.

Bubble tube systems
A bubble tube system is a simple, accurate and cost-effective method for measuring liquid levels in open or vented tanks.

How it works:

• A low, constant flow of air or inert gas is purged through a dip tube with its open end near the tank bottom.

• The flow must overcome the liquid’s hydrostatic pressure, releasing a steady stream of bubbles.

• With stable purge flow, the liquid level corresponds to the pressure inside the tube.

• A pressure or differential pressure transmitter converts pressure variations into level readings.

Where higher consistency is required, or where liquids are contaminated (e.g. pulp level in pump standpipes), water-purge systems are used instead of air.

Flow measurement
Level measurement underpins tank control, but flow technologies are equally critical:

• Variable area flow meters provide clear visual indication across a wide range of liquids—ideal where operators need quick verification of conditions.

• Metal tube flow meters offer robust construction for high-pressure duties common in chemical recovery and pulp processing.

• Oval gear flow meters deliver precise volumetric measurement, well suited to coating preparation and chemical dosing.

• Seal water flow meters (e.g. Kytola SLM) protect pumps and mechanical seals from dry running and contamination—vital where pumps handle everything from clean water to abrasive pulp slurries.

Selecting the right device
Choice depends on application and fluid characteristics. In digesters, where wood chips are cooked with chemicals at high temperature, sensors must withstand harsh conditions without compromising accuracy. Water separators that remove excess water from pulp often benefit from guided wave radar to avoid issues with foam or build-up.

When specifying systems, consider process temperature and pressure, as well as foam, vapour or dust. Environmental factors can also affect sensor performance and should be evaluated carefully.

Choose with confidence
Understanding available technologies—and where they fit in chemical recovery, stock preparation, papermaking and coating—helps ensure reliable operation and consistent quality. Partnering with a proven Kytola supplier such as Applications Engineering ensures access to best-in-class meters and transmitters, backed by expert guidance.

Many products are available for collection from our Sussex warehouse or for next-day delivery. Contact Applications Engineering to discuss your requirements and get recommendations for the ideal devices for your application.

For more information on How Does Liquid Measurement Work in Paper Mills? talk to Applications Engineering Limited