GB330166A - Improvements in consistency controlling devices - Google Patents

Abstract

330,166. Meyers, S. E., and Merritt, E. H. May 7, 1929, [Convention date]. Pulp, regulating consistency of; alarm and indicating apparatus.-The consistency of fluid suspensions, such as wood pulp stock, is automatically regulated by the addition of a consistency modifying agent e.g. water. A paddle, arranged to rotate in the fluid suspension, is driven through a train of gears; the train includes a movable member which moves in response to the driving effort required to rotate the paddle. This movable member actuates a controlling device e.g. a valve, which directly controls the utilisation of the consistency modifying agent. In Figs. 1 and 2, 10 is a reservoir or stuff box fed through the pipe 11. A partition 12 ensures the maintenance of a constant head. The rotating element 16 has concave blades 58, which carry round some of the solid particles. This is driven by the electric motor 17 through the worm 41 and worm wheel 40, the regulating device (shown in Fig. 3), the shaft 26, and bevels 33 and 34. The form of regulating device shown in Fig. 3 consists of a wheel 23, driven by the electric motor, coupled by means of a belt or chain 24 to the wheel 22 which is geared to the paddle. The belt passes round a pulley 43 which can move vertically. If the consistency of the paper pulp increases, more power is required to drive the paddle 16, the tension in the belt 24 increases and the sheave 25 is raised against the spring 47. This lifts the valve 51 off its seating and allows water to flow through the pipe 21 and into the bulk of the suspension, so rectifying the increase. Other means for operating the valve 19 may be employed such as an arrangement of differential gearing in which the shaft 87, Fig. 7, is driven and the shaft 83 is geared to the paddle 16. When the torque necessary to rotate the paddle becomes excessive, the yoke 85 turns slightly and operates the plunger 91 which controls the valve 19. In a third arrangement utilising planetary gears, the wheel 102, Fig. 8, is driven and transmits the motion to the wheel 96 through gears 99 and 99<1>. The outer wheel 96 is geared to the paddle. When the resistance to the motion of the paddle increases, the arm 100 turns, and operates the valve 105. An indicating device may be operated by the movement of the tension sheave 25. A mercury switch, adapted to light different coloured .lamps for different positions of the valve is shown in Fig. 5. The insulating tube 62 is moved about the pivot 71 by means of the arm 72 attached to the tension sheave. A globule of mercury 64 makes contact between the wire 65 and the wires 63, 63<1>, 63<11>, which are attached to flexible leads. Thus for different positions of the tension sheave 25, the tube 62 is tilted by different amounts, and various coloured electric lamps illuminated. The device is applicable to fluid suspensions which are treated under pressure, and to the control of consistency in other arts, for example, the consistency of clay compounds, glues, and the like.