| 摘要 |
This invention deals with the creation of a differential analogue signaller, which indicates the blockage of filters installed in treatment plants, reducing the pressure and the amount of natural gas. Said signaller includes an external body (5), having an internal collecting chamber (9), divided by means of an elastic membrane (18), into a pressure chamber (91), and into a counter-pressure chamber (92), in which the gas present above, and that present below the filter, respectively enter. Centrally the membrane has a sleeve, which axially slides on a pin, that carries a rotating indicator (15) on one of its ends. When, as a result of different pressures in the two chambers divided by the membrane, the membrane moves, the sleeve connected to it, transforms its sliding motion on the pin into rotational motion on the pin itself, across a sphere, which runs within a helical groove (30) made on the pin's surface. In an operative variant of the analogue signaller, a magnetic element (42) is present at the end of the sleeve, which provokes the closing of a switch connected to an alarm system, when the index of the signaller reaches a position equal to approximately 75% of the base scale. |
