Mineral buildup in heat exchanger tubing walls

[design-assoc]

In a geothermal heat exchanger where well water is cerculated up from one well and down another [some distance away] where water treatment is certanly not premissable; what techniques are available to minimize mineral? build-up on the exchanger [tube] walls.

[1] I have heard of putting magnets on both sides of the entry pipe that may help some and has been used sorrounding water heater entry pipes [What might be the mechanism of desolution here?]

[2] Is the extent of the buildup related to delta tempeture difference on the localized surface or more the material of the exchanger tube, and of the deposeted material as in the use of copper in a "tankless coil" for a residential oil burner. [Which clogs in 3 seasons]

[3] Has anyone heard of using plastic materials for heat exchanging "tubes" to limit buildup; although certanly at some loss of heat transmission; or do the deposets even stick to plastic. [ok in this situation of low opreating tempetures]

[4] Any other odd experience eg. constant [audio] vibration or circulating electric current locally in the tubes? to eliminate fowling and retain constant transfer performance

 

[design-assoc]

Adding to [1] above; http://www.chem1.com/CQ/magscams.html

Adding to [4] above; http://www.heatharvester.com/ION-How.htm

Not much information in eather case on the mechanism of opperation

Adding to [1] again; better explanation and practical examples; http://www.superiorwaterconditioners.com/data/PR-PM0797-5.pdf