| 摘要 |
<p>1,273,443. Mixing apparatus. BELOIT CORP. 17 June, 1969 [28 Aug., 1968], No. 30634/69. Heading B1C. The flow of fluid stock to be mixed in the blend chest 10 of a papermaking machine is automatically varied in dependence on its consistency, so that the ratio of stock components in the blend, on a dry mass basis, does not vary with the consistency of the component fluid stock. As described, softwood fibre stock, hardwood fibre stock, brokes and an additive (e.g. alum) are supplied to the blend chest 10 through pipes 48, 54, 58, 62 respectively, and the respective consistencies are measured by detectors 52, 56, 60, 64. A computer calculates the required flow rates of the four components, using signals from the detectors, the required total flow rate F D (determined by a level detector 16) and the desired stock proportions R A , R B , R H , R S (on a dry mass basis). The individual flow rates are controlled by feedback loops 30, 32, 34, 36, of which the loop 30 is shown in more detail. A flow detector 50 supplies a signal which is compared with the desired signal Fs and an error signal on line 42 controls a regulator 44 for a valve 46.</p> |
