| 摘要 |
<p>The unit incorporates a pneumatic relay and consists of two identical nozzles (7, 8), pneumatically in communication with the pneumatic relay of the said unit. The latter has two shutter plates (12a, 112a), one for each nozzle (7, 8), held in the position for shutting off the corresponding nozzle by elastically deformable spiral springs (13, 113) and a U-shaped element (16) mediumed by the said unit in a manner oscillating around an axis (16c) parallel to the said nozzles (7, 8) and acting on one or the other of the said plates (12a, 112a) in order to distance it from the respective nozzles. The said element (16) is moved angularly in one direction or in the opposite direction around the said axis (16c) by an actuator operating on the basis of the deviation between the actual value of the process and the desired, variable value. The unit tends to solve the problem of the passage from forward action to reverse action, with respect to the variation in the monitored quantity, without delay in the attaining of the exact value of the regulating signal. <IMAGE></p> |
