device for measuring pneumatic level of coal in coking plants

摘要

An arrangement for regulating the introduction of substances into chambers is disclosed and is particularly well-suited for the feeding of coal into coke ovens. The arrangement includes a chamber which is to be filled to a predetermined level and a feeding device is provided for feeding material into the chamber. The feeding device has a switch which stops the introduction of the material to the chamber when the level of the material reaches the predetermined level. The switch for the feeding device is electrically connected with a differential pressure switch which is actuated upon the generating of a predetermined pressure differential across it. The requisite pressure differential is generated by introducing pressurized gas into the chamber and an air compressor may be provided for this purpose. A sensing conduit, which is connected with one terminal of the differential pressure switch, extends into the chamber and has an end positioned at the predetermined level to which the chamber is to be filled. The pressurized gas admitted into the chamber sets up certain pressure characteristics in the sensing conduit which are changed when the level of material in the chamber reaches the predetermined level so that the gas no longer has free access to the open end of the sensing conduit. The change in the pressure characteristics causes a pressure differential to be established across the differential pressure switch which, in turn, activates the feeding device switch to stop the introduction of material into the chamber. In order to compensate for shock waves which may be generated in the chamber by the feeding of the material and which may cause a false signal to be transmitted to the switch of the feeding device, a compensating conduit is provided which has an end in the chamber and is connected with the terminal of the differential pressure switch opposite that to which the sensing conduit is connected. A supply conduit for the pressurized gas is also provided and introduces the pressurized gas into the chamber in the vicinity of the end of the sensing conduit.