Coriolis meters for pharmaceutical processing
The pharmaceutical industry uses high-purity liquid flow processes in upstream and downstream processing. Coriolis meters may be useful in applications such as fluid transfer between skids, batch filling, and feeding of growth media, glucose, and other nutrients into bioreactors. Here we discuss the benefits that Coriolis mass flow meters can provide to various pharmaceutical processes.
Advantages of Coriolis meters
Reliability and repeatability
When manufacturing drugs, reproducibility is critical. It is therefore extremely important to have a reliable, repeatable meter that is compatible with the various fluids involved in pharmaceutical processes. There are a few features of the Coriolis meter that make it an optimal solution.
The Coriolis flow path consists of a single straight or bent tube with polished surfaces and no fabrication joints. A key advantage of this design is that the flow path can be made entirely of corrosion-resistant metals and can therefore flow highly acidic or basic solutions and the chemicals used for clean-in-place. The lack of fabrication joints additionally prevents the flow meters from leaking. Therefore, Coriolis meters can provide repeatable, high-accuracy measurements for a wide variety of process fluids.
Straight tube vs bent tube Coriolis meters
The primary considerations when deciding between straight tube and bent tube meters is sensitivity and drainability. Bent tubes offer higher sensitivity, and straight tubes offer higher drainability. For applications with high cleanliness standards and less stringent accuracy requirements, straight tube meters are advantageous over bent tube meters.
Cleanliness and ASME BPE compliance
Pharmaceutical applications require high accuracy with a low risk of contamination for process liquids and gases. Coriolis meters can be easily designed to comply with ASME BPE standards for drainability, which is important for the sterilization of inline equipment. Since the fluid does not flow past any crevices and all surfaces are polished, Coriolis meters can be easily cleaned and sterilized, without need for disassembly – and there are few areas for unwelcome bacteria or microbes to grow.
High accuracy and low lifetime cost
Coriolis flow meters tend to have a higher cost of purchase, primarily due to their high accuracy. However, they are extremely versatile and require very little maintenance, leading to greater flexibility and lower lifetime costs of ownership than many other flow meters.
What makes Coriolis meters so versatile?
They can be used even as process densities change, and they can flow different fluids without the need for recalibration or reconfiguration. The meters also operate over a wide operating range. Together, these enable one Coriolis meter to be used for a range of applications with minimal servicing costs.
Applications for Coriolis meters in pharma
Raw material handling
The accuracy requirements of pharmaceutical processes differ depending on total batch size. For example, scaled down processes tend to have much higher accuracy requirements than larger batches. Raw material handling is often measured out by weight, using lower accuracy methods. However, when batch sizes or SOP dictate higher accuracy measurement methods, Coriolis meters can be easily used to flow and measure raw materials. A lower-accuracy flow meter may also be sufficient, however Coriolis meters have the added benefit that their measurements are not affected by changes in flow composition.
Water for injection
The water used to clean and disinfect skids between batches has high purity requirements, necessitating the use of a meter which can be easily cleaned and sterilized. Additionally, flowing large amounts of water has the potential to lead to a lot of waste of both energy and the water itself – which lead to higher process costs. Using a higher accuracy flow device can reduce waste and lead to lower overall process cost. Considering both purity and process efficiency, a Coriolis is a practical solution for water injection.
Pill coating requires accurate, repeatable application of small amounts of paint to pills, and also monitoring of airflow to pill coaters. Coriolis meters are able to meet the high-accuracy, low-flow requirements of these various pill finishing processes.
Coriolis meters are useful for filling applications in pharma (and a host of other industries). Because they function independently of conductivity and viscosity without losing any precision, Coriolis meters are more widely applicable and reliable than alternatives including measurements by weight, volumetric flow, or electromagnetic flowmeters. Because it is simple to design Coriolis meters with hygienic connections and without any crevices inside the device, they are a useful technology even in a downstream process.