R016600x

SECTION III - CLAYTON FEEDWATER PUMPS AND WATER SYSTEMS

3.1 GENERAL Clayton steam generator feedwater systems are designed with an open (hotwell), deaerator (D/A), or Semi-closed Receiver (SCR). The selection of the proper feedwater system is determined by the steam generator’s application, the installation environment, and other factors. Each system is discussed in detail in later paragraphs in this section. The feedwater system’s pipes, as well as the heating coil, are susceptible corrosion if proper feed- water treatment is neglected. Corrosion in the pipes are due to three fundamental factors—dissolved oxy- gen content, low pH, and temperature. Oxygen is required for most forms of corrosion. The dissolved oxygen content is a primary factor in determining the severity of the corrosion. Removing oxygen, and carbon dioxide, from the feedwater is essential for proper feedwater conditioning. Temperature and low pH affects the aggressiveness of the corrosion. Deaerators are designed to remove most of the corrosive gases from the feedwater. Deaeration can be defined as the mechanical removal of dissolved gases from a fluid. There are many types of deaer- ators; however, the ones most commonly used for deaerating boiler feedwater are the open (atmospheric), pressurized jet spray, and tray type. To effectively release dissolved gases from any liquid, the liquid must be kept at a high temperature. Deaerators are pressurized above atmospheric pressure (typically 3– 15 psig) to maintain the feedwater at a higher boiling point. The increased pressure and temperature releases the dissolved gases from the feedwater and those gases are vented to atmosphere. There are four skid package options available depending on the feedwater system (all options are not available for all models - contact your Clayton Sales Representative). The systems, skid package options, and required customer connections are described below. 3.2 SKID PACKAGES A. Individual Components The steam generator unit and all water treatment components are furnished separately. Placement of each component and its assemblies and interconnections are deter- mined by the installer. See Section 3.3 for customer connections. B. Feedwater Receiver Skid A separate skid consisting of the feedwater receiver, booster pump(s), and electrical control box mounted on a common frame is provided along with the steam gener- ator. Interconnecting piping between the feedwater receiver and booster pump(s), if applicable, and feed- water receiver trim component mounting, are included. If applicable (>200 bhp), electrical connections between the water level control, makeup water valve, and skid electrical control box are also included. No other water treatment components or interconnections are provided on this skid.

3-1

07/10/2015

Sect03_FeedwtrSys_xx4_g.fm