This website uses cookies primarily for visitor analytics. Certain pages will ask you to fill in contact details to receive additional information. On these pages you have the option of having the site log your details for future visits. Indicating you want the site to remember your details will place a cookie on your device. To view our full cookie policy, please click here. You can also view it at any time by going to our Contact Us page.

Close

Optimising production processes with radar technology

12 July 2023

Felix Glans explains how the latest non-contacting radar level transmitters are helping food manufacturers to increase product quality, throughput and safety.

Automated level measurement solutions play an important role in enabling food manufacturers to achieve the production efficiency gains needed to maximise profitability and meet consumer demand. To help ensure that the most suitable level measurement technology is selected for an application, there are certain criteria that need to be considered.

Being able to continuously measure product level in storage, mixing and batch tanks as accurately and reliably as possible is crucial. Precise level measurements help to ensure consistent product quality, increase safety by protecting against overfills and dry-running pumps, optimise tank utilisation and inventory management, and reduce product waste and production costs.

Level measurement instruments must also comply with the industry’s strict hygiene and food safety standards and need to be compatible with challenging process conditions – such as high temperatures, foam and turbulence – which can affect measurement accuracy. Devices need to be cost-effective, to help ensure a fast return on investment, and should also be easy to install and integrate into an automation system, to minimise complexity.

Technology options
A broad range of technologies can provide continuous level measurements, including differential pressure transmitters, capacitance probes and ultrasonic transmitters. While these technologies are relatively inexpensive they do have certain disadvantages. These can include requiring calibration, which increases complexity; being in contact with the product, thereby creating a food safety risk; and being susceptible to changes in process conditions such as density and temperature affecting their measurement accuracy.

Non-contacting radar level transmitters provide some significant advantages when compared to other technology options. They are top-mounted and do not touch the product surface, thereby minimising the risk of contamination, while changes in product density, viscosity and temperature do not affect their accuracy. The use of frequency modulated continuous wave (FMCW) technology and smart algorithms maximises their measurement accuracy and reliability, even when used in space-constrained skids and challenging, fast-filling vessels. They do not require calibration, and have minimal maintenance requirements thanks to their lack of moving parts.

For many years, this technology has provided accurate measurements in safety-critical industries such as oil and gas, but devices have typically been considered too bulky and costly for use in food production. However, the latest generation of instruments, such as the Rosemount 1408H Level Transmitter from Emerson, have been designed specifically for food and beverage applications, and can meet previous industry concerns about size and cost.

Here are some examples of how these innovative new transmitters are already providing significant benefits for food manufacturers.

Storage tanks
Radar transmitters rely on reflected signals – known as echoes – to perform level measurements. The latest non-contacting level devices use fast sweep technology to provide a continuous echo against the product surface. This enables them to collect up to 40 times more information than legacy instruments, which makes their measurements more accurate. Maintaining precise control of product levels in storage tanks helps to keep processes running smoothly, and avoids product wastage. This is because inaccurate measurements can sometimes result in tanks being falsely identified as empty, and large volumes of product being washed away during cleaning processes.

Another important challenge is to maximise tank utilisation. The design of the latest non-contacting radar level transmitters enables them to perform accurate measurements to the very top of the tank, where there would previously have been a dead zone. This optimises tank utilisation and production capacity, helping to increase throughput, meet customer demand and improve profitability.

Mixing and blending 
Level measurement devices face a range of challenges in mixing and blending applications, including turbulence, foam, and obstacles such as agitators in the tank. To meet these challenges, the latest non-contacting radar level transmitters use 80 GHz FMCW technology on a single electronic chip with embedded smart algorithms. This enables exceptional radar beam focusing, so that tank obstructions can be avoided and greater measurement accuracy and reliability achieved, even with such challenging process conditions.

A small footprint is important in food production, where many skids have tight piping arrangements. As previously mentioned, non-contacting radar level transmitters have traditionally been viewed as too bulky to use in food applications. However, with the latest devices incorporating electronics on a single chip rather than having a separate circuit board, their design has become much more compact and cost-effective, making them a good solution in space-constrained skids.

Reducing complexity is important for food producers, so the integration of level measurement devices with any automation system should be as straightforward as possible. The Rosemount 1408H provides a good example of how the latest non-contacting radar transmitters support this. It provides conventional 4-20 milliamperes, switch outputs and digital high-speed IO-Link communication, with HART communication capability to be added soon.

Cleaning processes
The latest non-contacting radar devices are IP69-rated and have been designed with robust, easy to clean and food-graded wetted parts, so that their performance is unaffected during clean-in-place (CIP) and sterilise-in-place (SIP) processes. These devices have a hygienic antenna that is flush with the process connection and insensitive to condensation and build-up, ensuring the removal of process residue during CIP and SIP. In addition, their broad range of hygienic process connections fit most common tank connections and sizes. These devices are also used as part of the CIP and SIP systems, where they help to prevent overfills and dry runs, and monitor the filling and discharge of the cleaning agents.

To reduce the risk of bacteria growth, the devices have a polished stainless steel housing with minimal crevices, enabling water and sediments to drain from their body when the outside of a tank is washed down.

Felix Glans is a solutions manager for Emerson’s radar level business.


Contact Details and Archive...

Print this page | E-mail this page