Flue gas desulfurization in catalytic cracking

Tell me first, why do you want to remove the filter screen and the frame?

Our pump inlet design team didn’t include a filter in the design

Our device doesn’t consider this; it should have

During normal operation, the filter screen and frame of the inlet filter for the slurry pump at the bottom of the flue gas desulfurization tower need to be removed. This is because the catalyst content in the bottom circulation fluid of the smoke stripping tower is high; therefore, a slurry pump is used for the quench water pump. During the initial trial operation phase after the plant’s maintenance is completed, since the pipes are quite dirty, a filter is installed at the pump inlet. It is necessary to remove the fine mesh of this filter while keeping its frame in place. Removing the fine mesh prevents catalyst from accumulating on it, which could lead to clogging and damage to the pump’s seals. Keeping the frame in place helps to avoid damage to the pump caused by larger debris. However, after the trial run is completed and there are no major debris in the pipeline, the skeleton must also be removed to prevent the catalyst from accumulating on it, which could lead to frequent clogging of the filter and ultimately cause the pump to lose pressure and have its seals damaged.

I think it’s best to avoid demolition; a separate filter layer can be added at the time of starting operations, and the framework can be retained during normal production (usually, the design does not include the Y-shaped filters that we add). The fact that production has continued for such a long time proves that this approach has no impact on normal operations. On the contrary, even if something larger falls, it will not affect the operation of the pump. If there is concern about mud accumulating here, the pump inlet can be checked by draining water daily; in addition, the check valve at the outlet should remain fully open.

As a supplementary note, there is no short circuit at the inlet of the pump; the design should be modified to include a short circuit so that the filter can be removed more easily.

That’s the idea; a slurry pump is used as the pump at the bottom of the tower

Well, it wasn’t included during the design phase, and there’s no shorting circuit with a filter at the inlet either; it needs to be added by oneself. At the start of operation, there are many impurities present, and even a very small piece of welding slag can damage the pump. Therefore, a Y-shaped filter screen can be added as needed, with an additional filter screen of slightly coarser mesh wrapped around it; during normal production, the Y-shaped screen can be kept while the temporary screen is removed

For the inlet filter of the slurry pump at the bottom of the flue gas desulfurization tower, it is necessary to remove the filter screen and keep only the frame.

Most slurry pumps are semi-open type with large clearances, so small weld slag has little impact