Stainless Steel Ejector Cooling Pumps for Marine Applications

I. Product Overview

Marine stainless steel ejector cooling pumps are high-efficiency heat exchange devices designed for ship thermal systems, using 316L austenitic stainless steel or duplex stainless steel 2205 as the main material. Based on the ejector pump principle (Venturi effect), they enable forced circulation of seawater, fresh water, or cooling liquids. The core principle is that high-pressure water forms a high-speed jet through a stainless steel nozzle, creating vacuum negative pressure in the suction chamber to draw in cooling media, which are then pressurized by a diffuser and delivered to the heat exchange systems of main engines, generators, and other equipment. After solution treatment and electropolishing reinforcement, the stainless steel material can operate stably in seawater with Cl⁻≤30,000ppm, suitable for marine main engine cooling, LNG pump cabin temperature control, and air conditioning systems, meeting IMO maritime regulations and international classification society certifications (LR, ABS, DNV, etc.).

II. Core Technologies and Material Characteristics

1.Stainless Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 50-800m³/h, suitable for ships of 2,000-40,000 tons

Head: 15-40m, self-priming height ≥8m, start-up response time ≤12s

Heat exchange efficiency: Ejector cooling efficiency ≥78%, 20%-25% higher than traditional centrifugal pumps

Corrosion resistance design: Electropolished surface (Ra≤0.6μm), passing 5,000-hour salt spray test without rust, 90% improved seawater erosion resistance

III. Technical Advantages and Innovative Design

1. High-Efficiency Heat Exchange and Anti-Clogging Capability

Non-rotating component design: Ejector pumps have no vulnerable parts such as impellers or shafts, capable of passing ≤5mm solid particles (such as marine organisms, rust), reducing clogging risk by 95%, suitable for cooling media with impurities.

Enhanced heat exchange structure: The diffuser adopts a gradually expanding spiral guide design (cone angle 8°-12°), combined with a turbulence promoter, increasing the heat transfer coefficient by 30%, with equipment temperature rise ≤25℃.

2. Extreme Condition Adaptability

Anti-tilt performance: Stable water supply under ship trim 25° and list 15°, adapting to ship swaying environments and ensuring continuous operation of the cooling system.

Low-temperature corrosion resistance design: Duplex stainless steel 2205 with thermal insulation coating can transport -40℃ low-temperature ethylene glycol solution, adapted to LNG ship pump cabin cooling and polar vessels.

3. Long Life and Convenient Maintenance

Wear-resistant reinforcement: Stainless steel impeller surface treated by supersonic flame spraying tungsten carbide (thickness 180μm), 5x improved wear resistance, service life exceeding 40,000 hours.

Modular quick-release structure: Pump body and pipelines use clamp-type quick-connect design, reducing single-component replacement time by 80% and maintenance costs by 45%.

IV. Typical Application Scenarios

1. Marine Power System Cooling

Diesel engine cooling: Duplex stainless steel 2205 ejector pumps provide seawater cooling for ocean-going cargo ship main engines, flow 300-500m³/h, combined with plate heat exchangers to control cylinder liner temperature at 85-95℃.

Gas turbine cooling: 316L stainless steel pumps transport fresh water to the gas turbine lubrication system, self-priming height 9m, adapting to multi-deck engine room layouts, controlling bearing temperature ≤75℃.

2. Special Vessel Cooling

LNG ship pump cabin cooling: Low-temperature ejector pumps transport -162℃ liquid nitrogen coolant, combined with vacuum insulated pipelines, to provide constant temperature cooling for LNG pump units, ensuring safe operation of pump cabin equipment.

Nuclear submarine reactor cooling: Radiation-resistant stainless steel ejector pumps (shielding layer thickness ≥60mm) ensure reactor loop cooling, meeting military-grade radiation resistance requirements.

3. Auxiliary Equipment Heat Dissipation

Generator cooling: Provide fresh water cooling for marine auxiliary generators, flow 100-150m³/h, control winding temperature ≤110℃, avoiding overheating failures.

Hydraulic system heat dissipation: with oil coolers to dissipate heat for deck machinery hydraulic systems, controlling oil temperature at 40-60℃, improving hydraulic component life.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Cooling medium: Choose 316L for fresh water/conventional seawater, duplex steel 2205 for high-salinity seawater/low-temperature liquids

Ship tonnage: Select 316L for <10,000 tons, duplex steel 2205 for ≥10,000 tons (better strength)

Temperature requirement: Electric tracing + thermal insulation layer (thickness ≥120mm) required for < -30℃, and duplex steel material recommended

2. Maintenance Key Points

Daily monitoring: Real-time monitoring of inlet/outlet pressure and bearing temperature (temperature rise ≤30℃), ensuring pressure fluctuation ≤±5%

Regular maintenance: Clean suction filters (filtration accuracy ≤8mm) quarterly, remove heat exchange tube scale with 3% citric acid solution annually

In-depth maintenance: Ultrasonic testing every 2 years, reapply passivation coating, and inspect seal aging

VI. Compliance and Certification

International standards: Complies with IMO MSC.302(87) Code for Ventilation and Air Conditioning of Machinery Spaces on Ships and ISO 8528 ship pump performance standards

Classification society certifications: Passed LR Rules for the Classification of Ships, ABS Rules for Building and Classing Ships, and DNV GL environmental certification

Safety specifications: Low-temperature products certified by ATEX (-196℃ applicable), stainless steel material 100% recyclable