Progress on seal oil systems for high-temperature heavy oil pumps in catalytic cracking
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Dear colleagues: High-temperature heavy oil pumps in catalytic cracking units are usually equipped with seal oil, which consists of diesel components. When the original unit was installed in 2009, it was decided that for one type of pump, injection-type sealing was used, while slurry pumps and reprocessing pumps employed a circulation system – that is, most of the seal oil returns to the seal oil tank, with only a small amount entering the pump chamber. The new design calls for all high-temperature heavy oil pumps to be of the injection type. The design institute gave the reason that the more advanced methods currently in use are those of the injection type; I remember that the injection method has been around for a long time, and it isn’t the latest approach. Question: What method does your device use?
What is the difference between injection type and circulation type? Ours is the seal oil inlet that connects to the pump via a branch from the seal oil circulation line. The old device from 1998
It can be determined from the process whether injection has occurred; if there is injection, there is no return line. Conversely, there is a return line for the oil tank to be refilled
Also, the amount of sealing oil in the return-type injection pump body is very small; on the contrary, in the injection type, if no orifice plate is installed on the sealing oil line, it is easy for water to enter the sealing oil stream, or the heavy oil pump may get emptied when too much sealing oil is used