Drying Furnace Temperature Monitoring

Reducing waste in the separator and electrode drying furnaces with Yokogawa’s distributed temperature sensors ensure comprehensive monitoring thermal events in real-time.

Application

Process time in a drying furnace is required for a film such as electrodes/separators of Lithium-ion batteries in order to evaporate their solvent. Maintaining a consistent and stable temperature inside the drying furnace correlates directly to product quality.
A drying furnace consumes power, which can cause wasted power if the process does not go well.

Challenges

During the drying process, the furnace temperature can become uneven due to several factors such as the furnace size, the heating method, and the type of coating materials. A temperature deviation caused by any of these factors can lead to quality defects and a drop in productivity. 
Traditionally, manufacturers have used single-point thermocouples or RTDs for heater control. This solution can create complex wiring that adds construction and start-up costs. The solution also increases the time required for the maintenance team to support the individual sensors throughout their lifetime and becomes unrealistic when multiple drying furnaces are deployed in a facility.
Although a thermocouple can accurately monitor temperature where it sits, it cannot monitor temperature distribution throughout a large furnace.
Holes in the monitoring grid can lead manufacturers to miss isolated temperature excursions out of the ideal range. Being unaware of the unstable temperature, manufacturers cannot correct the issue and might incur a waste of energy and effort.

Solution

An innovative temperature monitoring solution, Yokogawa’s distributed temperature sensor (DTSX) uses fiber optic cable to measure temperature. It provides temperature every 1 meter along the fiber optic cable.
As usual, point sensors should be used for controlling the heater of the furnace. By installing the fiber optic cable in the drying furnace in addition to existing point sensors, manufacturers can realize visualization of temperature distribution without blind spots. 

Also monitoring displays can be arranged according to customers’ requests.
DTSX200 has good performance and stability such as spatial resolution, temperature resolution, reproducibility, and response characteristic, which are an important factor for this application
 

Key Benefits

• Drying furnace operation can be optimized by improving problems thanks to fine-grained visualization of the temperature distribution in the furnace, and this results in increased productivity. 
• Fewer opportunities for waste of energy and time.
• Lower installation, operational, and maintenance costs due to fewer wires and parts.
• Decreased facility costs because DTSX200 can monitor multiple drying furnaces.