Corrosive handling pump choices

[Spilcher]

My problem is frequent pump wear due to corrosion. Would someone be able to provide advise on the pump type options needed to move caustic (na persulfate in Naoh as an example, oxidizes or reducing agents) with pH >10. I need a flow rate between 3 and 10 gpm. I need to pump the liquid <300 feet with minimal change in elevation (<30 feet). It is essentially a spray system similar to pesticide application but capable of handling more corrosive liquid. The pumped liquid would be at temps near 85celcius. Distance is important to operate in explosive atmosphere. End use flushing is routine but Perhaps there is a pump that is simple enough to repair internal components as needed.

The design includes a system mounted on a trailer. Fresh water tank with water heater, mixing tank for caustic sol'n, pump and hose reel with spray wand.

Thanks for any tips...

 

[itdepends]

I can't tell you what to use RE your specific application but caustic is not generally an issue for corrosion unless you use copper, zinc or one of their alloys. We have thousands of m3 of caustic at high concentrations (up to 1000gpL) in carbon steel tanks. Most of our pumps are steel- erosion is more the issue (solids) so we use white metal and other hardened alloys (for specifics I'd have to go and look)

If you're not using copper/zinc then your corrosion is more likely to be due to the oxidising agents. What sort of corrosion are you seeing and what are you flushing with at the end?

As a chem eng/metallurgist the first part of any answer I give starts with "It Depends"

 

[Spilcher]

i am seeing pump failure due perhaps to corrosion and solids but possibly to low temp viscosity of caustic. I'd like to find a pump with specs above to operate with a variety of oxidizers and corrosives. Maybe there is a particular pump design (i.e centrifugal, diaphragm, other) you might recommend. I typically flush with water, hot if available.

 

[bimr]

A good choice would be one of the air powered diaphragm pumps. What power is available?

 

[Spilcher]

120, 240

 

[Spilcher]

this might work. air and electrical supply is not a problem. it would be nice to simplify by not using air but if this is trouble free and eay to replace valve, then i could try

 

[Spilcher]

well, i keep sending thoughts in separate posts. solids might be an issue unless i screen/filter at intake. just another complication

 

[Compositepro]

Electric diaphram pumps are very commonly used in agricultural chemical spray systems. Air-driven pumps are nice when air is available.

http://www.hypropumps.com/EngineeredSearchResults.aspx#ProductType=Diaphragm+Pumps|isAccessory=false