Precise flow measurement for ultra-pure water

Ultra-pure water (UPW) — water that has been purified to stringent specifications — is a critical component in various industries where even minor contaminants can influence product quality and integrity. Industries such as pharmaceuticals, medical, power, and research laboratories rely heavily on ultra-pure water for their production and cleaning processes. To monitor consumption and ensure process efficiency, precise flow measurement of ultra-pure water is necessary. Anton Paar’s L-Cor Coriolis mass flowmeters provide a solution as they directly measure the mass of the liquid with the Coriolis force and offer a high level of cleanliness.

Flow measurement of ultra-pure water

The production of ultra-pure water typically involves reverse osmosis (RO) along with further deionisation and filtration stages. In this treatment process, all types of impurities, including organic and inorganic compounds, dissolved and particulate matter, volatile and non-volatile substances, reactive and inert substances, hydrophilic and hydrophobic substances, as well as dissolved gases, are removed to produce water of the highest purity. Since all conductive components have been removed, the purified water has a very low conductivity of 0.055 μS/cm. Due to this low conductivity, UPW cannot be measured with magnetic inductive flowmeters, which require a conductivity of more than 5 μS/cm.

Figure 1: Inline L-Cor Coriolis flowmeter.

Anton Paar’s L-Cor Coriolis mass flowmeters can be used to measure the flow rate of ultra-pure water, as this type of flowmeter directly measures the mass flow rate using the Coriolis effect. This effect occurs when a liquid or gas flows through a vibrating tube. Additionally, L-Cor flowmeters allow the independent determination of the density of the medium via the vibration frequency. This enables the device to output the volumetric flow rate of UPW as well.

Clean and hygienic flowmeter

To preserve the purity of UPW, it is crucial that the flowmeter exhibits a proven level of cleanliness and is constructed from a material that does not contaminate the purified water being measured.

The L-Cor 6000 flowmeter is well-suited for the precise measurement of UPW process flows, as this type of flowmeter meets the highest hygienic standards and has been awarded the European Hygienic Engineering and Design Group (EHEDG) certificate. Furthermore, the unique design featuring a single straight tube and wetted parts made of a polished titanium alloy ensures the highest purity grade. Due to its design, the flowmeter is also self-draining, offers excellent cleanability, and causes only a minimal pressure drop.

Applications of ultra-pure water

In the power generation industry, UPW is typically used as a source for steam generation to drive turbine combustors and steam boilers. The higher the boiler pressure, the greater the need for water of elevated purity. Impurities in the water can damage the boilers and associated systems and reduce the efficiency of the turbines.

There are also numerous applications for UPW in medical, pharmaceutical, and biotechnological facilities. Water that is free from toxins, microbes, and viruses is essential for applications such as water for injection, inhalation therapies, or as a product component. Additionally, UPW is used in this sector as a cleaning agent, for example, to produce clean steam for sterilisation purposes. In the production of pharmaceuticals, UPW is used as a solvent and in the formulation of medications to ensure that no impurities compromise the safety of the products.

Figure 2: Hygienic L-Cor 6000 flowmeter with single straight tube.

Installation points

The installation of flowmeters in systems that use UPW is important for efficiency, quality assurance, and process control.

In the power generation industry, for example, it is necessary to accurately determine the system’s liquid consumption. This ensures that the optimal amount of water is always directed to the steam production. Monitoring and adjusting the water flow in real time also minimises water consumption while maintaining maximum energy generation. This avoids unnecessary costs and optimises resource use.

Another important aspect is monitoring a continuous flow with a velocity of more than 0.9 m/s to prevent the formation of biofilms. Besides occasional chemical or steam disinfection, maintaining a minimum flow and minimising dead legs are crucial to reduce the growth of bacterial colonies.

In the pharmaceutical sector, Coriolis mass flowmeters are used to adjust the water supply based on production requirements. This precise measurement of the UPW supplied is essential to ensure the correct composition of the products. Minor errors could impact product quality.

Process solution: the L-Cor 6000 flowmeter

The table below provides the specifications of the L-Cor 6000 flowmeter.

Table 1: Technical specifications of the L-Cor 6000 flowmeter.

Benefits at a glance

The L-Cor 6000 flowmeter offers several advantages for UPW flow measurement:

• Accurate mass flow measurement up to ±0.15 % ±ZS
• Real-time monitoring allows immediate adjustment for perfect process control
• Maximisation of plant production time
• Maintenance-free design
   

To learn more about the L-Cor 6000 Coriolis flowmeter click here.

Contact us to discuss your application.

Anton Paar Australia I Email: info.au@anton-paar.com, Tel: +61 2 8315 4400

Anton Paar New Zealand I Email: info.nz@anton-paar.com, Tel: +64 9 414 3190