Pressure difference related to the filter

Is 0.6 MPa the pressure at the inlet pipe or on the filter? Is the pressure on the filter that high? If it is, then the pressure difference would be too large; if it’s the pressure at the inlet pipe, then the pressure on the filter wouldn’t be that high.

A valve can be added at the filter outlet to keep the pressure difference between the inlet and outlet below 0.3 MPa. In other words, the outlet pressure is made greater than 0.3 MPa, and then it is released into the air

It is also possible to install pressure-reducing valves and buffer tanks at the inlet to keep the pressure difference between the inlet and outlet below 0.3 MPa. Then it enters the filter.

The pressure difference of a filter is the pressure loss that occurs as fluid passes through it. The pressure difference that your filter has to withstand is 0.3 MPa; this refers to the pressure difference between the inside and outside of the filtering elements as impurities accumulate over time as a result of use. This pressure difference of 0.3 MPa is not closely related to the pressure at the inlet of the filter. For example, if the initial pressure difference of your filter is 0 and the inlet pressure is 0.6 MPa, then the pressure difference will not be 0.6 MPa but rather 0 MPa – because the filtering elements are clean, and there is no pressure loss as the fluid passes through them, so no pressure drop occurs. As the filter is used, impurities accumulate on it; when fluid passes through the filter, this results in a pressure loss. This pressure loss gradually increases as the filter continues to be used. The pressure difference that the filter can withstand refers to this pressure loss. So, as long as you install a pressure differential gauge at the inlet and outlet of your filter, it will show the difference in pressure between these two points. When this difference approaches 0.3 MPa, it’s time to clean your filtering elements; after cleaning, the pressure difference will return to a very low value. Otherwise, your filter element will be damaged and the filter will cease to function.

We encounter this issue with one of our processes as well: the filter elements often get flattened. Later on, by adjusting the valves at the inlet and outlet of the filter, we managed to keep the pressure difference across the filter below 0.3 MPa.

Using filter elements is rather troublesome; I specialize in bag filters and filter cartridges, with a filtration precision of 0.5–800 microns. Please give your support, haha

The analysis on the 5th floor is very comprehensive: a pressure differential gauge should be installed at the inlet and outlet of the filter, and a control valve should be installed at the filter’s outlet. When it is first put into use, pressure should be increased slowly, after which the control valve should be opened gradually; the filter needs to be replaced once the pressure differential reaches 3 KG.

Pressure difference and pressure resistance are two different concepts. If your filter can withstand a pressure of 0.6 Mp, then there should be no problem; you just need to control the pressure difference of the filter. A pressure gauge can be installed in front of the filter to keep the pressure difference at 0.3 Mpa.

Taking the KKF filter as an example: since the required filtration pressure difference is less than 0.3 MPa, we install a pressure equalization tank at the outlet of the filter, keeping the pressure at around 0.5 MPa. This allows us to control the pressure difference between the inlet and outlet at 0.2 MPa (which is less than 0.3 MPa). When this pressure difference reaches the set value, the filter undergoes backwashing, thereby preventing the pressure difference from exceeding the specified limit. A control valve is installed at the outlet of the equalization tank; its opening degree (and thus the flow rate) is adjusted based on the liquid level in the tank. Even if air is present at the outlet of the control valve, it does not affect the pressure in the equalization tank. The pressure in the upper part of the equalization tank is controlled using compressed air, with valves at the inlet and outlet of this compressed air used to regulate its flow rate. In practice, a constant pressure valve can also be installed at the inlet to control the pressure of the instrument air supply. The exhaust valve at the outlet is a manual valve that is usually kept closed. I’ll try to find a diagram to share later. There’s also the method mentioned by someone earlier, which involves using the outlet control valve directly to regulate the pressure difference. Generally, filters with pressure difference limits have a backwashing function, such as disc filters. This post was last edited by Pseudo Xiao Bao on 2009-4-12 at 12:55

I think 5 loops and 9 loops are the more accurate descriptions! ! !