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A vital tool for gypsum board manufacturers looking for increased product consistency and improved product quality is on-line moisture measurement and control. Similarly, moisture analysis in gypsum board production can help to determine precision dryer balancing, in addition to lower energy costs and product waste.
Complete Process Control
Throughout the gypsum board or wall board production line, on-line sensors can be utilized to better control the process. To start, infeed sensors monitor the incoming raw gypsum, to give a feed-forward control mechanism to actively predict the temperature and drying speed for optimum control.
A crushed rock sensor works together with the infeed sensor by supplying useful feedback data that correlates to the overall performance of the drying system. Having this information facilitates energy efficiency, in addition to a quality-controlled material feed into the calciner.
Next, a wet-end radio frequency (RF) sensor measures gypsum board moisture at the end of the forming line, for an early indication of dryer load.
After entering the drying zones, an ultra-high temperature sensor (working in temperatures up to 1000 °F, or 540 °C) and then high-temperature sensor (usually working in temperatures of 500 °F, or 260 °C) supply feed-forward information for the next zones’ drying.
The gypsum board moisture is quantified by an end of kiln sensor at the accumulator section before the unloader, giving feedback information for the trimming of the final drying zone. Low temp sensors usually operate in temperatures of up to 140 °F (60 °C).
Lastly, an out of kiln sensor quantifies finished board moisture. One sensor supplies a moisture measurement for one board stream. Not only does this measurement facilitate dryer balancing, it also supplies final drying zone trimming.
After the unloader, a transfer sensor provides a cross-board profile of the gypsum board and moisture profiling sensors give a detailed moisture distribution of the gypsum board for the highest level of moisture control available for gypsum board manufacturers.
Smart RF Moisture Management System
Sensortech Systems provides a variety of moisture measurement choices for the gypsum board, but the ST-3300 is the most intensive, robust instrument by far.
Configured with a number of mounting choices, this on-line instrument features Sensortech’s patented radiofrequency measurement principle, which is digitally enhanced for a much better standard of stability and resolution.
A variety of data interface options are available for direct integration into plant PLCs for automated control loops.
An open frame moisture sensor is one such solution and it is ideally suited to measure the total moisture content in gypsum boards. It is usually mounted on roller or belt conveyors.
As the finished board passes over the measurement field, the open frame moisture sensor takes a penetrating moisture measurement and averages the moisture content. Open frame sensors are highly versatile and are supplied in numerous custom sizes and can be mounted in kilns or ovens which operate in very high ambient temperatures.
This information has been sourced, reviewed and adapted from materials provided by Sensortech Systems, Inc.
For more information on this source, please visit Sensortech Systems, Inc.