One, Current Status of Oxygen Removal Equipment: As the operation years of the oxygen removal equipment increase, power plant operators have discovered during use that the dissolved oxygen does not meet specifications and the exhaust volume leads to increased energy consumption. There is a discrepancy in working pressure between the oxygen removal tank and the oxygen removal head (the tank's working pressure is slightly higher than the head's), and the operation is unstable. The oxygen removal head may experience significant vibration, and the dissolved oxygen in the outlet water may exceed the standard (15 micrograms per liter for the national standard low-pressure oxygen removal equipment), sometimes reaching 50 micrograms per liter. The equipment's long-term operation efficiency is low, affecting the safe and economic operation of the main unit and boiler.

II. Issues with Standard Oxygen Scavengers:
The deaerator is a device used to remove dissolved air and oxygen from water, while also serving as a mixed-type heat exchanger, which combines the functions of heating and storing boiler feed water. The steam used for heating comes into direct contact with the feed water within the deaerator, exchanging heat to raise the feed water to its saturated temperature at working pressure. This process allows the non-condensable gases in the deaerator to escape from the feed water, and the escaping gases, carrying a small amount of steam, are discharged through the exhaust port.
In the widely used deaerator series in our country, the rotary film-type thermal deaerator is one of them. Water is jetted through the membrane holes to the tube wall, forming atomized water droplets as it descends. These droplets are then mixed and heated by upward flowing superheated steam, due to the large and uniform contact area, allowing for thorough mixing and heating of water and steam, with some non-condensable gases escaping. Its deaeration and heat transfer effects are somewhat superior to those of the spray plate and spray packing deaerators. However, many issues still exist in the operation of the rotary film-type deaerator.
Under normal operating conditions, it generally meets the usage requirements; however, during variable conditions (especially at low operating conditions), it is difficult to achieve the originally planned deoxygenation effect.

(2) The deaerator's operating pressure has reached the rated working pressure, yet the outlet water temperature is below the saturation temperature at this pressure. Oxygen and other non-condensable gases in the water are not easily separated.

(3) To address the issues mentioned in item 2, it is often necessary to increase steam volume during operation. Consequently, the pressure in the deaerator rises. To maintain the deaerator's pressure, the steam排放 at the upper exhaust port must be increased, which in turn wastes steam resources and is不利于 energy conservation and consumption reduction.
(4) After a long period of operation, the packing layer may deform and fall off due to the impact of steam and water, losing its elasticity. This reduces the heat exchange surface area between steam and water, and simultaneously increases the steam-water resistance, causing the internal pressure of the deaerator to rise insufficiently, deeply affecting the deaeration efficiency.
(5) Short steam-water heat exchange process, high steam consumption, uneconomical, unstable operation, and excessive oxygen content. Structure and performance of the spiral membrane improved (patented technology) deaerator:

Section 3: Structure and Performance of the Oxygen Remover with Improved Spiral Membrane (Patented Technology)
1. Rotating Film Improved Oxygen Remover Structure: The heat and mass transfer mechanism of the rotating film improved oxygen remover's tube differs from the existing jet, atomized, and froth-type methods, primarily integrating three heat transfer methods—jet through rotating film and suspended bubble—into one. It boasts high thermal efficiency, offering substantial heat absorption and decomposition capabilities; transforming natural falling film into strong forced film, enhancing the renewal rate of the liquid film, and causing it to strongly rotate and draw in a large amount of steam along the tube wall, boosting heat exchange and mass transfer functions. It modifies the opposite-facing froth to suspended froth, increasing the steam velocity in the layer and maintaining the gas channel during high-velocity conditions; integrating the three independent heat and mass transfer devices into one, completing them within a single unit's components. Due to its high efficiency and unique functions, it breaks through the technical performance of existing oxygen removers.
Through numerous tests, analyses, and modifications, we have repeatedly transformed the internal components of the spiral membrane thermal deaerator deaerator head, resulting in specific implementation methods for deaerator modifications. After the deaerators at the power plant were modified according to this plan, the deaeration effect was excellent. Our new water film deaerator (an improved spiral membrane type) is a novel deaerator structure researched and promoted over the past decade. It addresses the deaerator efficiency issue of high dissolved oxygen in feedwater at low entrance water temperatures and frequent changes in operating conditions for both heating unit and peak load units. 2. Performance of the spiral membrane improved deaerator:
The Improved Spiral Membrane Deaerator is a next-generation product of spray packing and spiral membrane deaerators. It combines the advantages of various deaerators and undergoes a deep optimization design. It first replaces the exhaust baffle with an efficient steam-water separator, significantly reducing water and heat loss in the exhaust, keeping the exhaust volume below 1% (5% for spray type, 3% for spiral membrane type).
The five-stage deoxygenation principle of the new deoxygenator ensures high deoxygenation efficiency during normal operation. The dissolved oxygen level in the outlet of the low-pressure deoxygenator can be maintained below 15 micrograms per liter for an extended period. The surplus deoxygenation space allows the deoxygenator to operate at high loads (usually designed at 50% of the rated output, but can also be custom-designed as required) or in low-temperature (low-pressure) water intake mode (i.e., full water refilling operation).
The new oxygen removal system has been operating in the market for nearly a decade, with over a hundred manufacturers having been transformed, and more than 500 sets of equipment in operation. It is widely recognized as the upgraded and replaced product for the spray plate, spray, and rotating film oxygen removal systems.
3. Key features of the improved spiral membrane oxygen removal unit:
Operation stable, high deoxygenation efficiency, good adaptability to load changes. Achieves the boiler water and steam quality standard (high pressure: 7 micrograms/L, low pressure: 15 micrograms/L or less) within a short period (usually around half an hour). Additionally, not stringent requirements for water quality and temperature.

IV. Technical Analysis and Comparison:

V. Renovation Process and Timeline:
1. Remove the original deaerator head and replace it with an upgraded spiral membrane deaerator head, or dismantle the interior of the original deaerator head and install the new deaerator components.

2. Connect the original steam and water intake pipes according to the layout requirements of the new deaerator.
3. Engineering renovation to be completed in approximately 5 days.
Appendix: Internal Structure Diagram of the Improved Rotating Membrane Deaerator

Six, Expected Post-Transformation Effects
Dissolved oxygen at the outlet can be controlled within the national standard range of ≤15 micrograms per liter.
2. Eliminate the phenomenon of varying pressure in the degasser head water tank and abnormal vibration of the degasser head during the operation of the original degasser.

3. Steam-water separation efficiency at exhaust outlet reduced from the original 3% to less than 1%, significantly improving economic performance.