Valmet expands applications for OC transmitters
Valmet says its Optical Consistency Transmitter (Valmet OC) has a reputation for accuracy, reliability and ease of installation since its introduction four years ago. Now there are three new models for applications that have been particularly challenging for in-line optical consistency transmitters in the past. This includes measurement of eucalyptus pulp, recycled fiber and chemical pulps.
Sharing the same basic components and modules, each new transmitter has a probe and total consistency measurement method optimized for use in a special process environment i.e. recycled fiber.
Eucalyptus pulp applications. Eucalyptus pulp has different optical properties compared to other pulps. This has led to the design of the special optical sensor and measurement method of the Valmet OCE. Results with the new transmitter in several commercial installations have already been successful where competing in-line optical transmitters have failed. A typical application is the control of LC-refiner feed consistency, where improved refiner freeness results and reduced specific energy consumption have been reported.
OCC and RCF applications. OCC and RCF processes are a challenge for any measuring device where sand, metal and other contaminants as well as non-organic fillers are present. The Valmet OCR features a robust probe to survive the harsh physical environment and a measurement that tolerates the ash variations that prevent the use of other in-line optical consistency transmitters. Valmet says that installations in OCC processes before coarse screening have proved the probe’s robustness and the total consistency measurement accuracy is excellent throughout the stock preparation area even with wide ash variations.
Chemical pulping applications. The Valmet OCS now features a sapphire window to withstand chemicals used in chemical pulping. All three new transmitters’ passive measuring probes are connected via fiber optic cable to the measuring unit. The probes are temperature and vibration resistant as well as self-cleaning even in the demanding environment of recycled fiber processing. Offering simple and low cost installation, the 12-mm diameter probe with ball valve also makes insertion and removal possible without special tools or process stop required.