Can the column be recoiled?

This is a problem troubling many liquid phase users.
Many people say that if the column head is blocked and the pressure is increased, the backwash effect is very good!
Many people, including the engineers of the manufacturer, said that recoil is not recommended. If it is flushed, the column efficiency will be affected.
There are various opinions on this issue, which makes it almost a mystery in the industry.
So, today we will analyze and discuss whether the column can recoil and what is the reason behind it?
As we all know, the vast majority of liquid chromatography columns are filled with silica gel beads with a diameter of several microns. After these silica balls are filled into the chromatographic column under high pressure, the two ends of the chromatographic column need to be sealed with sieve plates, which can not only let the mobile phase pass smoothly, but also ensure that the silica gel beads stay in the chromatographic column without running out with the mobile phase.
Of course, the aperture of the sieve plate should be small enough, otherwise it will not seal the silica ball.
However, if the pore size of the inlet sieve plate is very small, there will be a problem, that is, it is easy to be blocked by the sample. If the sample is slightly not treated or dissolved, the sieve plate will be blocked, the column pressure will be increased, and even the column will be discarded.
Therefore, many manufacturers have decided to make the pore size of the sieve plate at the inlet of the chromatographic column larger than that of the outlet sieve plate, so as to ensure that the silica gel ball will not be washed out of the column, and the column head will not be blocked easily.
However, in this case, the column can not be recoiled.
Because if recoil, when the pollutants blocked on the inlet sieve plate are washed out, the packing on the column head may also be washed out, resulting in the reduction of column efficiency and even the scrapping of chromatographic column.
Here, let's summarize:
If the aperture of the sieve plate at the inlet and outlet of the column is the same, it can be recoiled. It doesn't matter whether it is used in front or back, even if the direction is marked on the column.
However, if the aperture of the sieve plate at the inlet and outlet of the chromatographic column is not consistent (generally, the inlet aperture is larger than the outlet aperture), the backwash may cause the packing leakage and reduce the column efficiency.
?
So which chromatographic column inlet and outlet sieve plate aperture is the same, which is inconsistent? Is it written on the column instructions?
Sorry, the answer is rather disappointing. The instructions of most chromatographic columns are almost not marked.
Based on personal understanding and communication with industry insiders, we can only give you the following suggestions:
The chromatographic column with small particle size less than 3.5um should not be recoiled. Because the smaller the size of the column, the more inconsistent the pore size of the inlet and outlet sieve plate.
Core shell columns like poroshell do not recoil.
Most of the 5 um columns can be recoiled.
If you have any friends of chromatographic column manufacturers to see this article, I hope you can contact us and provide more information about your chromatographic column.
As a chromatographic column user, we need to know more about it, rather than simply saying "recoil is not recommended".
For more related technologies, please consult MS technologies technicians