Hydrazine Deoxygenation Dosing Device

Process Principle

Oxygen can cause electrochemical corrosion of metals such as carbon steel in humid environments, resulting in damage to ferrous components. The reaction is as follows:

Fe→ Fe²++2e O₂+2H₂O+4e→4OH

Such corrosion is most likely to occur and is relatively severe in feedwater systems with high temperatures, therefore, it is essential to remove dissolved oxygen from the water. Hydrazine deoxygenation is a commonly used chemical deoxygenation method in high-parameter boiler units. It exhibits strong reducing properties in alkaline solutions and can reduce dissolved oxygen in water, as shown in the following reaction:

N₂H₄+O₂→N₂+H₂O

Process Overview

This device mainly consists of five parts: a liquid metering pump system, a dissolution and preparation system, a metering and dosing system, a safety system, and a control system.

Hydrazine is drawn into the metering system via a water ejector, then added proportionally to the dissolution and mixing system with demineralized water or condensate, and finally added to the boiler feedwater via the metering and dosing system. Dosing control can be manual or automatic, based on control signals from a higher-level system.

This device can not only add hydrazine, but with slight modifications, it can also add other oxygen scavengers such as carbazide and dimethyl ketoxime.

Application areas

High-pressure and higher parameter boiler feedwater treatment

Data parameters