Hot Water in Wastewater Lift Station

[jartgo]

There is an existing lift station serving a single industry which uses boilers in its operation. Through the process, some of the boiler water makes its way to the lift station, thereby introducing water that is approximately 130 deg F in the wetwell.

The station has been in operation for about three years, maybe a little longer. Problems were noticed last year with PVC fittings (as expected) and corrected.

The question has come up as to whether or not the heated water (it's practically constant at 130 degrees or so in the wet well), will have an adverse effect on the pump power cables, float cables etc. The pumps are 5HP, submersible grinder.

I'm leaning towards the fact that it's been in operation with no apparent effect on the cables thus far, but thought I'd see if anyone had any other experiences. Thanks in advance.

 

[dicksewerrat]

Who owns the station? Has anyone looked at the pipes down stream from the station outlet? Is there any corrosion of the station walls?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[jartgo]

Everything in the station appears normal, with the exception of the steam of course. No adverse effects are apparent.

 

[bimr]

The insulations is good to 75 Degrees C (167 F) so you should have no problems with the electrics.

http://www.philatron.com/NewCatalog/TAB11/Submersible_Pump_Cable-index.html

http://www.calvert-wire.com/show_product_list.php?subcatid=101

 

[SewerEng]

Not sure how much of a difference that would have on the NPSHA but you might want to take a look at that to see what affect the higher temps will have.

 

[bimr]

The hot water will have minimal effect on submersible pumps NPSH.

 

[nackra]

Are there any industrial pretreatment requirements in the sewer use ordinance?

If I recall, I have seen discharge limits set for industrial users to reduce impacts on public sewer systems.

 

[jartgo]

Just as follow up to the recent responses, I don't think the (relatively minor) temperature will have an effect on the hydraulics.

The sewer use ordinance does not address water temperature, and quite frankly, the Town doesn't necessarily want to impose any limits on this industry (its an appealing revenue stream), as long as it's not causing any damage to the equipment.

I did find that the literature for many pumps lists a maximum water temperature of 140 deg F. Some pumps even listed this as only an intermittent condition with 105 F being the normal maximum. I haven't had time to discuss with a pump rep yet, but I assume this is related to the life expectancy of the seals.