Beater of valley type is used for laboratory beating of pulp under standardized condition. The degree of betting can be varied. Beating is a preliminary step to the testing of the physical properties of pulp. In principle, this standard applies to all kinds of satisfactory results with certain extremely long fibred pulps, such as cotton linters
Apparatus : The lab beater consists of a pulp chest of acid proof ground and polished internally. The pulp chest is divided in the centre and forms a circular basin in which the pulp can flow around. A hardened, portion separate the two halves of the pulp chest. The pulp between the beater roll and the beater plate. The beating pressure is controlled by means of the lever which is loaded with dead weights.
A measured quantity of pulp with a specific consistency is beaten between the knives in the beater. Samples of the beaten pulp are taken at predetermined intervals during the beating.