How to improve the performance of a dosing pump?

A pilot plant is an important step from lab-scale to commercial-scale production. In the chemical industry, it is common to build pilot plants to minimise risks in the final plant, especially in advanced chemicals. In this ‘step-in-between’ it is essential to measure the critical fluids very accurately to draw the right conclusions in time.

Dosing pumps are often used in pilot plants to control the liquid flows, but the accuracy, fast & efficient data of the liquid flows is the key to your success. Therefore, in this blog, I will go deeper into the benefits of using a flow meter combined with your dosing pump for the best pump performance.

Flow meter in the pilot plant

Based on market research and analysis, it became clear to us that customers from the chemical industry can use either industrial flow meters or laboratory flow meters in their pilot plants. Both are not ideal. For our product management team, this insight was our starting point. Thanks to the hard work of our technical colleagues, we have been able to develop a flow meter that is specifically suitable for pilot plants. But first let’s start with analysing the situation…

Accurate, fast and efficient data for pilot plants is a need

When measuring critical fluids, the amount of highly accurate data – which is needed to make the right decisions for the final plant – need to be collected accurate, fast and efficient. If fluids cannot be measured accurately enough, tests must run for a very long time to finally collect the required data to build decisions on. Pilot plant tests usually cost a lot of money, especially when a long testing time is involved. However, when the system is equipped with accurate instrumentation, the test duration can be shortened dramatically.

Dosing of fluids – using a dosing pump

There are several solutions for you to choose from when dosing fluids in your process. Many users choose a volume-based dosing pump. A dosing pump is a typical solution to dose a certain amount of fluid into a process. This volume-based approach is good enough for non-critical processes. But if the process is critical, the operator needs to be sure that the dosing pump is dosing the correct amount. Dosing pumps cannot check themselves. Especially if a leak, a changing backpressure or a contaminated pump chamber occurs, the indicated flow is not reliable anymore. This is the point where an accurate flow meter is closing the gap.

Dosing solution with Coriolis flow controllers

Pump control – using a dosing pump with flow meter

If you decide to integrate a flow meter in your process as well, the flow created by a dosing pump (or metering pump) can be measured and corrected. How? The flow meter measures the mass flow and the measured value is used to correct the dosing pump directly (read: ‘pump control’). So, a flow meter with (external or internal) controller functionality converts the dosing pump into an advanced closed-loop dosing system! This is how a dosing pump finally becomes part of an accurate dosing solution.

Using a mass flow meter for pump control in a pilot plant

But which type of flow meter should you choose to use in your pilot plant? As a dosing pump only measures the volume mechanically – and the volume of a fluid can be influenced by many parameters – a mass flow meter would be the preferred choice. It compensates for the weaknesses of the dosing pump. A Coriolis mass flow meter measures accurately and independently on fluid properties, so if you combine a dosing pump with a Coriolis mass flow meter, you get a very reliable and accurate dosing system.

Accuracy, dimensions and robustness of the flow meter

Many types of Coriolis mass flow meters are available on the market, but can all of these become a perfect fit?
In many cases, the application is special in one way or another. As previously mentioned, in pilot plants several things come together. That is why the following three specifications are particularly important when you select your Coriolis mass flow meter:

In laboratory applications, the flow meter should perform very accurate to enable scientists to find the real truth. Specifications from manufacturers are sometimes difficult to achieve in practice, which is why we recommend you to perform a practical test to measure the practical performance of such a flow meter. The written performance is not always the same as in practice.

A Coriolis flow meter used in pilot plant built by Zeton (copyright: Zeton)

At industrial applications, reliability and robustness are usually the most important assets. But this can come at the expense of other specifications, such as accuracy. Do not get me wrong, reliability and robustness are important, but truth-finding prevails in a pilot plant, as in the lab. So, is a typical industrial Coriolis mass flow meter the best choice in your pilot plant?
Besides, there is another important point that requires attention, namely the dimensions of all components in a pilot plant. Size matters, especially concerning the compactly built pilot plants. Most typical industrial Coriolis flow meters bring a serious amount of space and weight into the equation. Therefore, the skid or entire system must be scaled up significantly, which introduces the necessary costs and system inertia.

Dosing solutions for pilot plants

So, we can conclude that two worlds come together in a pilot plant: lab and industry. Dedicated instrumentation offers you the best pilot plant performance. An accurate dosing pump is a good solution for non-critical processes. But for critical processes in a pilot plant you should select the right mass flow meter, where practical accuracy is relevant, but compactness and robustness must also be of sufficient value.

Industrial Coriolis flow meters, MI-series

Taken the conclusion into account, the Bronkhorst Coriolis MI-series mass flow meter addresses all relevant specifications. In the first place, it measures very accurate, but it is also compact and mounted in a very robust stainless-steel housing. In addition to these required specifications, it is also equipped with an integrated PID controller, so it can operate a pump or valve extremely fast on its own without the need for additional electronics. The MI-series are specially designed for your chemical pilot plant!

How flow meters improve the performance of your dosing pumps