Post-Boiler Condensate Conditioning

Where condensate is severely contaminated due to excessive iron content, high pH levels, or alkalinity, carryover, or process intermediaries, it is common practice to consider dumping the condensate. This obviously is not a particularly sensitive course of action in an era of high-profile environmental issues and is additionally expensive because of disposal costs and the loss of valuable heat content. 

As with the basic pretreatment of MU water for smaller boiler plants applications, various sieves, screens, cyclones, and strainers may sometimes be used for filtering condensate, essentially to remove iron oxide particles. Also bag, cartridge, and candle filters (with or without a filter aid) are employed (see section 9.2.4.4). 

Because of the HW temperatures involved, metal basket strainers tend to be popular, but in-line bag filters using high temperature-resistant bags are also widely used. The benefit of strainers and bags over cartridges and candle filters is that where iron oxide transport is the primary problem, the iron particles are trapped inside and cannot fall off or otherwise recontaminate the CR system. 

Electromagnetic separators sometimes are used as filters for the removal of ferromagnetic iron oxide from condensate and thus prevent it from being transported back to the boiler. 

NOTE EMS systems are legitimate technologies and should not be confused with magnetic devices proposed for pretreatment of MU water. 

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