Fig. 53.—A “Tower” Beating Engine with Centrifugal Pump for Circulating Pulp.
Power Consumption.—The long treatment required to thoroughly pulp a strong material demands a great amount of power. Engines differ considerably in their power consumption, and comparisons are frequently made in terms of the power required to beat a given weight of pulp. But this is not always a true criterion of efficient work. Some types of beater are suitable for producing certain results, and the mere substitution of a beater consuming less power is worse than useless unless it can be shown that the same effects are being obtained. The efficiency of the Hollander for the beating of rag pulp, in spite of the high power consumption, is a case in point.
Fig. 54.—Working Parts of a Modern Refining Engine.
With this factor properly considered, the power required for beating becomes an interesting study. Many detailed experiments have been published from time to time, the most recent being those described by Beadle.
Patents taken out in Connection with Beating Engines.
1855. Park (1170).—A small steam engine was attached to the shaft of the beater roll, so that it could be driven direct.