A couple of years ago i specified a rotary screw compressor package to provide service air to a small water treatment plant that i was building. The air requirements are relatively small but peaky , during periods where there are numerous valve operations. To give you an idea of air requirements the compressor has done about 360 hours in two years. The unit is about as small as a rotary screw goes and is classed as a 4kw unit.
The unit was selected primarily based on low noise output as there are residences quite close by. I had also used similar units in similar applications elsewhere without a problem, although these had been specified by people other than myself.
This unit recently destroyed itself with the compressor unit being full of rust and water but also no oil.
So we started talking with the manufacturer/suppliers and i got this massive tale of woe how the unit was the wrong selection and they need to run for extended periods and they need to get hot to vaporise the water etc. Maybe thats fair enough and a couple of suppliers told me the same story.
However i also spoke with an expert who has considerable service and overhaul on these units and he says " All that is correct, but these units use special oil that maintains lubrication with considerable amounts of water mixed in , so provided the oil is changed out regularly etc it should be okay."
As far as i can tell (obviously none of the operation staff want to know anything about any of this) the unit that has failed has had no oil changes (despite a 6 month/2000 hour requirement) and i am dubious about whether it has even had an oil level check whilst in service. This is obviously not good. However is this lack of maintenance the actual cause of the problem or is the real problem this short run time as the manufacturer suggests?
At least one of the other units that have worked elsewhere successfully gets regular oil changes and so far has had no problems despite operating on the same cycle times. Based on this and the low noise requirement i am tempted to go back with a rotary screw and "insist" on better maintenance practices.
What annoys me is that none of the manufacturers or suppliers say anything about the need for extended running when you buy these units nor is it published in any of their manuals or application notes.
Does anyone have an opinion or experienced similar problems?
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
The unit was selected primarily based on low noise output as there are residences quite close by. I had also used similar units in similar applications elsewhere without a problem, although these had been specified by people other than myself.
This unit recently destroyed itself with the compressor unit being full of rust and water but also no oil.
So we started talking with the manufacturer/suppliers and i got this massive tale of woe how the unit was the wrong selection and they need to run for extended periods and they need to get hot to vaporise the water etc. Maybe thats fair enough and a couple of suppliers told me the same story.
However i also spoke with an expert who has considerable service and overhaul on these units and he says " All that is correct, but these units use special oil that maintains lubrication with considerable amounts of water mixed in , so provided the oil is changed out regularly etc it should be okay."
As far as i can tell (obviously none of the operation staff want to know anything about any of this) the unit that has failed has had no oil changes (despite a 6 month/2000 hour requirement) and i am dubious about whether it has even had an oil level check whilst in service. This is obviously not good. However is this lack of maintenance the actual cause of the problem or is the real problem this short run time as the manufacturer suggests?
At least one of the other units that have worked elsewhere successfully gets regular oil changes and so far has had no problems despite operating on the same cycle times. Based on this and the low noise requirement i am tempted to go back with a rotary screw and "insist" on better maintenance practices.
What annoys me is that none of the manufacturers or suppliers say anything about the need for extended running when you buy these units nor is it published in any of their manuals or application notes.
Does anyone have an opinion or experienced similar problems?
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
