A simple method for measuring the height of a gas holder

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An accurate indication of the gas holder height in fertilizer production is particularly important; operators in the gas generation and compression units must always be aware of the gas holder height to prevent accidents. The method introduced in this article is simple in principle, easy to install, accurate in indication, and capable of transmitting signals over long distances for display. Working principle: A circular oil storage tank is installed at the top of the gas holder’s bell. When there is no gas in the gas holder, the oil storage tank remains horizontal relative to the Hall effect transmitter mounted on the gas holder’s water tank. As the bell jar rises with the increase in gas, the oil storage tank also rises, gradually coming above the Hall transmitter. The transformer oil in the oil tank is connected to the transmitter through a rubber tube at the bottom of the tank, thereby continuously increasing the pressure on the Hall transmitter. The output signal of the Hall transmitter increases as the pressure applied to it rises, and this signal is sent to the display instrument, which indicates the height of the gas tank. Selection of instruments and calibration: The YSH-1 type gauge transmitter is used for the conveyor. The operating pressure can be determined using the following formula, based on the effective height of the gas tank in use at the factory: P = h·r, where P represents pressure and h represents the height difference ； Density of r-transformer oil. When the bell jar rises to the upper limit (i.e., 100%), the transmitter output should be at full scale, namely 20 mV. When the bell jar rises to the midpoint (50%), the transmitter output should be 10 mV. When the oil storage tank is horizontal with respect to the Hall transmitter, the transmitter output is O. The display instrument uses an XWB or XWG graphic electronic potentiometer. The scale is calibrated automatically, but the full scale must be 20 mV. If this is not achieved, the range can be changed to meet the requirements. Installation notes: The oil storage tank is installed on one side of the bell jar; when there is no gas in the gas holder, it must be horizontal with respect to the Hall effect transmitter. The rubber hose from the oil storage tank to the Hall transmitter must be long enough. When the gas holder’s dome rises to its upper limit, the rubber hose connected to the transmitter should be slightly longer, to provide sufficient extra length. After installation, the Hall transmitter can be covered with plastic sheeting to prevent rusting and circuit short circuits caused by exposure to wind and rain outdoors.