There is air leakage at the shaft and casing of the centrifugal fan. Do any of you have any good solutions?
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1) There is air leakage at the shaft of the centrifugal fan and at the casing; the gas contains ammonium sulfate that tends to crystallize. Due to the high pressure inside the casing, the leaked gas enters the bearing box, which results in poor condition of the grease inside the bearing box. 2). Ammonium sulfate present in the gas tends to crystallize, causing these crystals to adhere to the impeller and leading to an imbalance in dynamic balance, which in turn results in significant vibration. Does anyone have a solution to the above problems?
Suggestions: 1. Add isolation sealing gases, such as instrument air, nitrogen, or similar gases, for isolation and sealing； 2. Install sealing devices, such as rubber or labyrinth seals.
Does this device require regular cleaning of the impeller? If so, the existing seal should be cleaned at the same time. I’m not sure whether gas media is oil-free. If possible, the existing seal (which may be a comb-shaped seal) can either be used as is, or an extended comb-shaped seal can be fabricated; a ring tube is added in the middle section and connected to the fan inlet, so that the leaked gas is returned via the negative pressure at the suction end. Apply yellow glycerin to the seal. For reference.
Personally, I believe that the presence of ammonium sulfate in the gas, which tends to crystallize, can cause blockages in the labyrinth seal grooves, thereby affecting the sealing performance.
Currently, there is no sealing mechanism at the shaft and housing. Due to the large vibrations caused by the imbalance in the dynamic balance of the fan impeller, it seems unsuitable to use comb-tooth seals; in my opinion, packing seals would likely yield better results.
High vibration; perform dynamic balancing to reduce vibration； Add labyrinth seals using carbon rings, PTFE, etc.
It is recommended to use imported magnetic oil seals; feel free to message me if you need them. Thank you!
A pressure-resistant gas seal can be added at the leak point, or a magnetic oil seal that prevents gas from entering the bearing box can be installed there.
There are two issues here: 1. Can the material of the fan crystal allow for the presence of gas seal pressure and the medium gas? 2. Visually, there is no space between the current fan air leakage point and the bearing housing to accommodate both an air seal and a magnetic oil seal simultaneously. Therefore, the possible solutions are: 1. Survey the existing bearing housing end caps in order to design a fully inserted, through-type magnetic oil seal that helps maintain the cleanliness of the bearing housing. 2. The fan shaft seal uses a John Crane 28SC seal, which should provide good sealing performance against crystalline substances. If necessary, feel free to contact me to discuss a comprehensive solution and select products with better reliability.