Long-Term Neutralization of Acidic Condensate from Gas Condensing Boilers

The pH of wastewater needs to remain between 6 and 9 to protect water organisms. Condensates from a gas condensing boiler have a pH value of about 3. An optimal way to neutralize the acid condensate is to use cheap material such as dolomite. An old-style neutralization box (NB) was tested with a standard faction of dolomite. However, it did not sufficiently neutralize the condensate. Therefore, several tests were performed involving changes to the construction of the neutralization box, a finer fraction of dolomite and aerating the condensate in the neutralization box. In summary, a new NB technology with partitions, a finer fraction of dolomite and condensate aeration proved sufficient in the neutralization of the pH of the condensate in the short and long terms. It depends on what material the heat exchanger is made of in the condensing boiler. The aluminum content reduces the effectiveness of dolomite in the long run, so aerating the condensate in the NB is recommended, which leads to its more effective neutralization.

Automated summary

Maintaining a pH value between 6 and 9 in wastewater is crucial for protecting water organisms. The use of dolomite is an effective and affordable way to neutralize the acidic condensate from gas condensing boilers. However, the effectiveness of dolomite may be reduced in the long run due to the aluminum content in the heat exchanger, so aerating the condensate in the neutralization box is recommended for more efficient neutralization.