The direct feed filter for diesel hydrocracking is flushed frequently
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Dear colleagues, at present our diesel hydrocracking unit uses both catalyzed diesel and direct diesel feed. Direct diesel has a lesser impact on the filters; the filtration precision of these filters is 20 microns. When there are large fluctuations in the quality of the catalyzed diesel, the filters need to be backwashed more frequently. Sometimes, when the catalyzed diesel is very dirty, continuous backwashing occurs, leading to filter clogging. Moreover, the pressure of the catalyzed diesel feed is higher than that of direct diesel, which results in feed interruptions and an inability to maintain the liquid level in the raw material tanks. I think a filter should be added before the catalyzed diesel enters the system, but I’m not sure exactly where it should be installed or what specifications it should have. It is known that catalyzed diesel contains a lot of water, and fluctuations in its quality can result in the presence of catalysts and large particles. How can we make modifications to avoid the negative effects of direct catalyzed diesel feed on the backwash filters, as well as on the direct diesel feed and the raw material tanks? I seek advice from experts. . .
Given that the fuel acceleration flow is unstable and contains water, the best approach is to add a fuel acceleration buffer tank in addition to upgrading the filter, using nitrogen as the pressure head. It can stabilize the flow rate as well as remove moisture.
Without a filter, can a buffer tank with two baffle plates be used? . . Sometimes, it carries large particles such as catalysts. . .
Generally, for directly fed coker diesel and catalytic diesel, don’t plants have filters? The filtration precision at the exit of the plant is around 50 microns, if I remember correctly.
Generally, the precision of hydrogenation backwash filters is 25 microns. To address this issue at its source, the party responsible for supplying the oil should be accountable, and the backwashing process should be installed in the upstream equipment. Reservation on the device. The same is true here; during backwashing, especially when using quick-change tanks, the raw material is extremely dirty. Coordinate with the upstream party to ensure smooth transfer of raw materials between tanks.
The upstream fuel feeding is probably done by pumping directly; well, it’s better to address the issue at its source. . .
Consider whether the pressure is too high, whether the gaps in the backwash filter elements are uniform, and whether the precision of the filter elements meets the requirements.
It is possible to add two dewatering tanks to the tank area, used for removing water from the fuel and precipitating mechanical impurities; these two tanks can be used in rotation (one for feeding, the other for supplying the device). This was the approach used in the original design of our facility. Another option is to separate the filters for the treated fuel from those for the raw fuel – this allows for control over the feeding ratio and prevents interruptions in the supply of raw material.