Problems with Shengda’s magnetic pumps for low flow rates and high head pressures
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There is a Sundyne magnetic pump on site, with a head of 188 meters and a flow rate of 3 cubic meters per hour. It features two stages of impellers: one centrifugal impeller and one turbine impeller, with an NPSH of 1 meter. Medium: anhydrous hydrofluoric acid. This pump breaks down frequently; the main issues are severe wear of the thrust disc, as well as varying degrees of damage to the silicon carbide bearings! Experienced brothers, please share how to save it!
First, check whether there are any foreign objects such as solid particles in your medium? Dry friction due to lack of fluid? Excessive axial force? It needs to be checked one by one.
Check whether the pump inlet filter is damaged; if not, install one.
Magnetic pump media are generally required to have good lubricity, and this requirement becomes even more critical when used in high-speed pumps. The analysis of axial force imbalance issues is caused by problems with the turbine disc or bearing wear.
The key reason why this pump breaks down frequently is that the medium is anhydrous hydrofluoric acid. It’s a shame that my pump can only reach a pressure of over 70 meters; otherwise I would get one for you without any problem.
The head difference is too large! Hehe! What pumps can you recommend?
There are no particles; this can be confirmed! There is now suspicion that some of the HF vaporizes after entering the pump!
HF has no impurities and no filter!
There’s nothing I can do; I specialize in single-stage pumps, and the maximum head achievable for a pump with a flow rate of 3 cubic feet per second is just that much. Your pump is multi-stage, so it can achieve a higher head. The pump I made is made of fluorine-lined material; your pump’s problem isn’t caused by cavitation in the HF acid area.
Axial force imbalance. Is the side of the thrust disc worn? Take a look and judge for yourself.
Has the silicon carbide bearing cracked? Are there any signs of wear or damage on the outer magnetic cylinder and the isolation cover? Any signs of cracking? I have encountered such situations; excluding factors like vaporization and impurities, the main cause is excessive axial force. You can check the random data to see what the installation clearance is for the thrust bearing and bearing housing of that model of pump Within its range, appropriately increase the gap.