Thermal Remediation for Managing Insect Pests

In addition to costly repair and replacements, damaged mechanical structures and equipment can have a significant impact on production—causing downtime.

As the heat treatment is progressing, check temperatures in locations where you suspect insects are commonly found to ensure temperatures are above 122 degrees Fahrenheit. If temperatures are below 122 degrees Fahrenheit, insects will survive; therefore, move fans to eliminate “cool spots” or place additional heat sources in the area. Properly monitoring temperatures will ensure optimum results. Dr. Subramanyam’s research in commercial facilities has shown that the speed of insect death was positively related to how quickly temperatures reached 122 degrees Fahrenheit, and negatively related to how long temperatures were held between 122 and 140 degrees Fahrenheit.

Monitoring Temperature During Heat Treatment

Accurate and consistent temperature monitoring during heat treatment processes is crucial to protect valuable mechanical devices and facility structures; protect electrical components; and ensure all areas of the facility have reached and sustained effective temperatures to minimize the possibility of pests repopulating.

Since most food processing facilities weren’t built to accommodate heat treatment monitoring, facility managers are required to retrofit temperature monitoring tools and equipment—often having to run lengthy amounts of cable before each scheduled heat treatment.

A seven-story flour supply mill in the Midwest installed resistance temperature detectors (RTDs) throughout their mill to help monitor the facility during heat treatments. Prior to each heat treat, cabling was run to the RTDs. Some points were easy to access with cabling, while others were more remote. Since flour mills have multiple stories, the process was labor intensive and time consuming.

The mill eventually installed a wireless network to access temperature information throughout the facility without running cables to the RTDs. Wireless nodes were wired to the RTDs and mounted remotely throughout the facility. The RTDs signal is communicated through the node and transmitted wirelessly to a remote gateway. The gateway was able to communicate temperature data to the centralized control, which would log the data and post results on an HMI.

By using wireless technology, grain mill operators can reliably monitor any remote area while communicating temperature status.

Radio and I/O terminals contained within a single housing unit rated IP67— reduces the need for additional enclosures. With this setup, users have the flexibility to install, uninstall, and reinstall in a new location as heat treating cycles are complete.

To ensure scalable coverage, it’s important that wireless systems enable users to connect multiple nodes to one gateway. For example, Banner Engineering’s DX80 gateway connects up to 47 nodes—and each node can be connected to up to four RTDs.

To enable operators to communicate through steel and concrete, operators should select a 900 mhz radio because it has better penetration than 2.4 ghz radios through concrete floors and walls. Banner radios come in frequencies of 2.4 ghz or 900 mhz and up to 1 watt of power. The 900mhz radios tend to do a better job of penetrating steel walls and concrete and are often used in buildings. It is important to note that while this bandwidth is available for use in the U.S. many other countries don’t allow it. Banner also provides radios with site survey mode to allow users to send test packets of data across the network to confirm radio communication. The radios then report how many data packets were received.

Conclusion

Heat treatment is an EPA-compliant alternative to methyl bromide for managing insect pests in food and beverage facilities. Achieving and maintaining appropriate temperatures is important during heat treatment to ensure all insects are killed–and to protect the structural integrity of the grain mill and its components. Wireless technology provides an efficient and reliable solution to accurately monitor and control temperatures.