Questions about naphtha
Thread Content
When naphtha is supplied to the cracking unit, it must pass through a filter; in winter, this filter often gets clogged, disrupting the normal operation of production. I would like to ask experts for ways to reduce the frequency of filter clogging. Thank you. . .
Can you explain clearly what kind of thing is clogging the filter? You can try adding a buffer tank and cleaning it regularly.
Do you mean that the viscosity is high in winter? When naphtha solidifies, it forms many small lumps, which become oil nuclei (that’s how we usually refer to them). In such cases, a filter with heating should be installed, depending on the actual conditions
Recommendation: Design a system with two filters that can be switched between use, and install pressure gauges at the inlet and outlet of each filter. As sediment accumulates in the filters, the pressure drop increases; by monitoring the changes in pressure difference indicated by the pressure gauges, it is possible to determine when it’s time to clean the filters.
Thanks, brother upstairs. . . The current situation is that this filter is a fine filter; we use both filters simultaneously, and when one of them gets clogged, we use nitrogen at around 0.6 MPa to perform backwashing. But even after rinsing, it doesn’t last long. This causes the outlet pressure of the pump to reach the specified maximum pressure. Sometimes it exceeds the maximum pressure. If filters are not used, it can easily lead to coking in the cracking furnace tubes and affect the activity of the arsenic removal agent in the naphtha arsenic removal system. There is heat tracing on the naphtha inlet line.
I agree with the third floor’s suggestion; it would be better to provide heat tracing for the filters as well and to control the oil temperature properly.
Where does your naphtha come from? There can’t be that many impurities. Our factory also uses naphtha as a raw material, and it doesn’t have as many impurities as you claim.
In this case, it is likely that the tank used for storing naphtha has seen its anti-corrosion coating wear away due to the corrosive effects of the naphtha stored there for an extended period of time; as a result, when the liquid was drawn out through the pump lines, it clogged the filters
The filter was cleaned again today; the filter screen was already heavily covered with sludge from the naphtha. . . It has been cleaned several times, and no anti-corrosion coating or mechanical impurities were found; the only thing present was sludge. . . If heat tracing is added to the filter, considering the high flow rate, almost no heat exchange will occur. The pore size of the filter screen is 150 microns