I need to specify a system to remove 1.0 ppm Fe and 0.5 ppm Mn from about 100 gpm. Can anybody reccomend 2 or 3 system manufacturers with with good track records.
This forum is specifically for engineering topics and not commerce, so your post might be removed.
I will try to answer your question from an "Engineering Tips" point of view.
Since you specifically mention the product, Manganese Greensand, why don't you contact the company that mines and manufactures this material: Inversand Company of Clayton, NJ. You can find contact info through an internet search. I think they can put you in touch with a qualified systems manufacturer in your area.
Although it isn't, Greensand is becoming a generic term. Kinda like Kleenex.
There are several filter manufactures that have products that utilize a media composed of or liken to greensand. Some are a other sand materials that have been coated, some naturally mined, etc.
Some of major pressure filter manufacturers you might contact for Iron Removal systems are:
Tonka Filter
General Filter
Hungerford & Terry
Marlo Filter
Roberts Filter
Good eyes, bimr! I missed the high temperature factor. Inversand, the manufacturer of Greensand, indicates precautions should be taken above 80-degrees F.
Another acceptable means of removing oxidized iron and manganese from hot water is by using a high-rate anthracite filter (or filters, in parallel)ahead of the softeners. At 100 gpm rate of flow, a 42" diameter pressure filter with a 48" deep bed of #1-1/2 Anthracite should work very well for this application.
For hot water service, vessel coatings or linings are tricky. De-lamination from "cold wall effect" is a common problem. Make sure you contact a manufacturer who has experience with hot water systems.