What Is A Calorimetric Flow Switch?

calorimetric flow switchWhen measuring flow in order to maximize energy savings and to implement environmental regulation and management one term that you may have heard is ‘calorimetric flow switch’. So, what is it? How do they work? In today’s article we are going to take an in-depth look into the calorimetric flow switch so that you can get a better idea about how they work, what kind of applications and benefits they have, and a better overall understanding in general. Let’s talk about the calorimetric flow switch and what it can do for you!

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A quick little history on Calorimetric flow monitors

Calorimetric flow monitors actually go back a ways in history. Attributed to L.V. King in 1914, the technology is based on the heated-wire anemometer which employed a heated wire as well as a standard temperature sensor which could gather data based off the dispersion of the heat in relation to the flow around it. This was originally applied to air velocity as well as liquid flow in pipelines but it would not be until later in the 60’s and 70’s when this technology would be incorporated into industrial usage. As it contained no moving parts, no pressure or temperature corrections, and retains accuracy over a wide range of flow rates this technology was quickly adopted and has been slowly built upon as the years have passed into the models of today. The modern versions of L.V. Kings work can be integrated with ‘Internet of things’ devices in order to collate data from multiple locations so that more granular management of pipelines and air ducts may be performed and while these extra features are nice it is interesting to note that the basic design is still the same as those L.V. King prototypes!

What are the applications of a Calorimetric Flow switch?

In imparting a better understanding of a calorimetric flow switch it is useful to know some real-world applications for which they are utilized. So, what kind of applications do these flow switches have? Also known as thermal flow monitors, these switches monitor the flow of gases and liquids. Some common used for calorimetric flow switches are as follows:

  • Protection measure for dry run pumps
  • Cooling circuit monitoring
  • Cleaning machines (specifically spray jets)
  • CIP process monitoring
  • Cleaning applications for components and bottles
  • Cooling tools

What are the benefits to using this technology?calorimetric flow switch

There are many benefits to be obtained by employing this technology in order to track thermal flow. Cleanrooms, for instance, are an excellent application of this technology. You are going to have pipelines that need to have a particular temperature maintained for liquids or for gas in order to meet strict cleanroom standards and a calorimetric flow switch allows you to ensure that these standards are being met. Further, these units may be networks in order to provide real-time information on these vital resources whether in a cleanroom, industrial, or commercial application. It’s data at your fingertips that can help to ensure that everything is running properly.

What is the Calorimetric measuring principle?

The calorimetric measuring principle is the magic behind these switches. Applying specifically to the transfer of gas or liquids, it is based on laws of thermal transfer and conduction. Generally utilizing two sensors, these switches allow you to monitor the transformation of heat energy in order to accurate ascertain the flow rate that is going on behind the scenes in your pipeline.  Temperature may also be

“The dissipation of heat can help to determine an accurate measurement of flow”

monitored during this time and the rough version of what occurs is that one of the sensors is heated to a target amount so that the dissipation of heat can help to determine an accurate measurement of flow. Let’s take a closer look at this process.

So, how do they actually work?

In order to go into a little more detail we will want to break things down into two category types of heating. Regulated heating and Continuous heating, to be specific. So, what occurs during these processes? Let’s compare:

  • Regulated heating – With regulated heating your calorimetric flow switch is going to typically work by the means of two sensors. One of them is heated and suspended in a solution so that temperature differences between the sensors are going to be reliably constant, allowing for comparison data to be gathered. Further, as the velocity of the monitored flow increases then further power is required to heat the sensor in the technical suspension in order to maintain the difference constant that helps to determine the flow measurements. This allows for a direct and accurate assessment of the flow within the pipeline you are monitoring.
  • Continuous heating – For continuous heating applications the principle is going to be performed in a quite similar fashion. Two sensors are going to be employed in the calorimetric flow switch, with one sensor directly measuring the temperature of the flow within the pipe and a secondary sensor (typically a wire wrapped heating element) which is constantly heated so as to give a data contrast that may be read and compared to the temperature as a whole. Electronic circuits take a note of the differences in temperature as well as the cooling effect that the flow has on the heated sensor. In cases of higher flow there is going to be less of a difference in the temperatures of the sensors whereas with a slow flow a greater difference is going to be noted. As molecules in the medium pass by, packets of heat are collected and transported away and the more molecules which are passing then the greater the cooling effect that will be seen with a calorimetric flow switch present.

calorimetric flow switch

In closing

Today we have discussed calorimetric flow switches (also known as thermal flow switches) in an effort to give you an inside look into how they work, what applications they support, and the benefits of this technology. Whether you need it for industrial, commercial, or cleanroom applications this is definitely some tech you should check out now. It will definitely save you money in the long run!