On the measurement of evaporator liquid level
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Our facility has newly installed two-effect evaporators. The transmitter specified by the design institute for measuring the liquid level is of the EJA220A series, with a range of -45 to -20 KPA. How should this calibration be carried out? How to install it? Urgent! Urgent! Urgent! ! !
It is best to provide the data to the manufacturer, who will then supply a transmitter that fits within the required measurement range； For self-migration, you first need a vacuum pump and standard calibration equipment; the accuracy of EJA should be 0.075, and your calibration equipment needs to have an accuracy higher than that. Is that achievable? For installation, proceed as with a regular transmitter, only the sealing requirements are more stringent.
The evaporation section for pulp alkali recovery? Hehe, it’s quite rare to come across someone from the papermaking industry in Haichuan. The installation location depends on the equipment drawings of the evaporator, which indicate the position and height of the level gauge openings; go to the site to check. There are usually two DN80 flange connections. As for the negative drift of the instrument, check the manual – you can handle it using a handheld controller
The EJA220A seems to be a single-flange (diaphragm-type) level transmitter...... For this type of single-flange level transmitter, is the high-pressure side connected to the flange on the user’s tank, and is a pressure tap used for the low-pressure side?
Yes! ! What’s really bothering me right now is how to carry out this migration; the range is -45 to -20 kPa. I hope experts can help with this? ?
The transmitter is installed according to the equipment drawings. If the design institute uses EJA220A series transmitters for design purposes, the equipment should be equipped with DN80 or DN100 flanges for installing level gauges. It is advisable to first install a gate valve of the same specification, then attach the single-flange transmitter, and finally connect it to the negative pressure side of the single flange using pressure transfer pipes through the instrument installation openings at the top of the equipment. A DN10 gate valve should be installed at the pressure tapping point for negative pressure; a condensation tank is connected behind the valve to facilitate the addition of isolation fluid, as well as to ensure stability in instrument measurements. When there is no liquid level in the evaporator, unscrew the plug of the vacuum side isolation tank, fill it with isolation fluid (the liquid of the component to be evaporated that is present in the container can be used), reattach the plug, and open the upper and lower pressure sensing valves. At this point, the negative pressure value indicated by the instrument represents the negative drift of the instrument, which should be set as the instrument’s zero point (the 4MA point). Add 25 to this value and use it as the range point, and then the gauge can be used.
The EJA220A level differential pressure transmitter is used to measure the level and density of liquids containing solids and precipitates, as well as steam, and then converts these values into a current signal output of 4-20mA DC. The EJA220A can also communicate with each other via the BRAIN operator, CENTUM CS/μXL, or HART 275 operators, allowing for settings and monitoring to be carried out through them.