How to deal with easy crystallization of triamines using instruments?
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I would appreciate it if experts could advise on methods to prevent crystallization when using pressure transmitters with triamines, as well as the appropriate instruments to use
The pressure gauges and transmitters should be diaphragm-type; we are also installing 30,000 tons of melamine. . .
Please describe your operating parameters in detail
For flanges, simply fit them onto the pipes; in areas where the pressure is not high and the temperature is suitable for contacting liquids, no valves are even necessary
First, use a flange-mounted pressure gauge or pressure transmitter with a diaphragm box; it is also advisable to have a flushing device available, as this will result in very good measurement accuracy. Additionally, providing appropriate heat tracing or insulation at the installation location can also reduce the impact of medium crystallization.
It can be solved using a blow-by pressure transmitter
It can be solved using a blow-by pressure transmitter
There are two types of melamine production systems. One is the low-pressure method (also known as the one-step method), which involves a reactor and a crystallizer; ammonia backwashing can be used effectively for this process, and convex diaphragms (80–100 MM) can also be employed for detection. However, this method does not work at high temperatures – above 300 degrees Celsius, it cannot be used； The second method: The high-pressure process allows for continuous production; its process flow is longer than that of the low-pressure method, and the pressure is higher (reactor pressure of 8.0 MPa). In this system, a diaphragm is used for high-pressure monitoring, while in the low-pressure section of the apparatus, either a backflush type or a diaphragm type can be used. Easy crystallization is mainly due to lower temperatures; on one hand, insulation should be improved, and on the other hand, ammonia backflow can be utilized if conditions permit. Backblowing cannot be performed using other media.
Reply to 1# fumeiqing: When using an ammonia gas instrument for pipeline purging, it is essential to install a flow-limiting orifice plate at the flange – that is, make a small hole in the blind plate – in order to reduce ammonia consumption and improve the purging effect by regulating the flow rate!
Our factory has installed flushing devices on some instruments that are prone to crystallization, and the results have been very good; the original poster might want to give it a try.