Moisture Measurement | Applications

Wood and Paper Industry

The M007 microwave resonance sensor is particularly well suited for measuring the moisture in well-mixed, pre-dried wood fibers and chips. Production of wood pellets depends at every stage of production on factors like purity size of particles, bulk density and particularly the moisture content of the material. For the purpose of in line moisture determination the M007 system offers a solution that is compatible with every production plant and can be deployed from the start of the process to the finished product.

During the entire process of plywood, particle and fiber board and wood pellet production, measuring the product moisture plays a decisive role. If the product moisture is too high or too low, it will lead to lower quality, or further processing of the intermediate products may be stopped altogether. Ongoing and accurate moisture measuring allows operators to quickly correct the process if there are any problems and helps to ensure a high level of quality standard.

APPLICATION AND MEASURING POINTS

MEASURING POINT 1: DRYER ENTRY

In case of varying water content in the raw material like wood shavings or saw dust, the drying process can be controlled using the inline moisture analysis method at the dryer entry point. This enables optimal material throughput at minimal power consumption. The measuring accuracy is typically 0.2%.

MEASURING POINT 2: DRYER EXIT

At this point, the residual moisture as a result of the drying process is continually monitored. This data is useful for optimization of the drying process as well as for controlling the subsequent conditioning. Here, the measuring accuracy is 0.2% in the moisture range of 0–18%.

MEASURING POINT 3: CONDITIONING

At the end of conditioning, moisture resulting from material mixtures and humidification is checked. Here, humidification can be controlled accurately.

MEASURING POINT 4: PELLETIZATION

A press station at the optimal point of operation in regard to pellet quality, throughput, wear and power consumption often requires adherence of a narrow tolerance for material moisture typically at 12% +/- 0.5%. Reliable control of moisture at the entry point of pelletization can be decisive for the whole pelletizing process.

MEASURING POINT 5: END PRODUCT

Continual measuring of moisture data in the end product enables a seamless documentation of batches of production and adherence of required standards. This prevents an otherwise expensive rate of waste and ensures compliance with stipulated standards. The measuring accuracy for the finished pellets is typically 0.2% in the moisture range of 0-12%

PAPER AND PRINTING INDUSTRIES

An important quality characteristic of the paper processing industry is the moisture, profile of rolls of paper. Due to their high-speed measuring technology, microwave resonance instruments for on-line measurements can work within a production line on the fast-moving webs of paper. Moisture will be measured not only at the surface but also inside the paper without being influenced by varying grammage or color hues. Moisture sensor capabilities include the measuring of glue layers applied to paper and the drying of printing inks.