Marine Ejector Fire Pump

I. Product Overview

Marine ejector fire pumps are the "emergency core equipment" of ship fire safety systems, designed specifically for offshore fire fighting. They pressurize seawater or freshwater into high-speed water streams through the ejector principle, which can be directly used for fire extinguishing or to drive fire monitors and sprinkler systems, quickly controlling the spread of fire. Constructed with cast iron (HT200), bronze alloy (ZCuAl9Fe4Ni4), or stainless steel (316L) as the main material, they rely on the high-speed jet of the ejector to form negative pressure and draw in water sources. After pressurization in the mixing chamber, the water is sprayed out from the nozzle, achieving self-priming and high-pressure conveyance without complex impeller structures. The pump body undergoes anti-corrosion treatment and pressure-resistant processing, with a service life of ≥10 years in -5℃~60℃ environments. It meets the requirements of IMO International Convention for the Safety of Life at Sea (SOLAS) and fire equipment certification from classification societies such as RS, LR, ABS, and CCS, widely used in fire emergency systems of cargo ships, passenger ships, oil tankers, container ships, and other vessel types.

II. Core Technologies and Material Characteristics

1.Material Selection and Performance

2.Key Technical Parameters

Flow range: 20-200m³/h, suitable for ships of 500-50,000 gross tons (e.g., 10,000 gross ton ships require flow ≥50m³/h)

Head coverage: 30-80m, meeting the long-distance fire fighting needs from deck fire hydrants to the bow/stern (including pipeline resistance losses)

Medium compatibility: Capable of conveying seawater (sediment content ≤1%), freshwater, and fire-fighting foam mixtures (foam concentration ≤6%) with temperatures ranging from -5℃ to 60℃

Self-priming performance: Self-priming height ≥6m, priming time ≤30 seconds, capable of directly drawing water from overboard without manual priming, suitable for emergency quick-start scenarios

Response speed: Time from startup to rated pressure ≤60 seconds, supporting remote linkage control (linked with fire alarm systems) and automatic startup in case of fire

3.Safety and Explosion-Proof Design

Explosion-proof certification: Motors adopt Ex d IIB T3 Gb explosion-proof grade, suitable for Zone 2 hazardous areas such as engine rooms and cargo oil tanks, preventing sparks from igniting oil and gas

Overload protection: Equipped with thermal relays and circuit breakers, the motor automatically powers off when overloaded and can be manually reset after cooling to avoid continuous faults

Impact-resistant structure: The pump body and base are connected elastically, capable of withstanding the impact of ship heel ±15° and trim ±10°, ensuring stable operation during fire fighting

III. Technical Advantages and Innovative Design

1. Efficient Jet Fire-Fighting Capacity

Dual-stage ejector structure: Adopts a "nozzle + mixing chamber + diffuser" dual-stage design, increasing water flow speed by 30% compared to single-stage ejector pumps. It can still maintain a jet speed of 25m/s at an 80m head, with stronger flame penetration capability.

Wide flow regulation: Flow can be steplessly adjusted within the 30%-110% rated range through frequency conversion control or valve adjustment, adapting to scenarios such as small flame extinguishing (small flow) and large-area fires (large flow).

2. Corrosion Resistance and Reliability Enhancement

Stainless steel flow channel treatment: 316L flow components undergo electrolytic polishing (Ra≤0.8μm) to reduce seawater salt adhesion, showing no rust after 5000 hours of immersion in 3% salt spray environment, suitable for long-term ocean-going use.

Cast iron pump anti-corrosion coating: The inner wall of HT200 pump bodies is sprayed with a ceramic composite coating (0.2mm thick) with a hardness of HRC60, improving seawater erosion and wear resistance by 60% compared to ordinary cast iron.

3. Ship Emergency Adaptability

Quick start system: Equipped with an emergency battery pack (battery life ≥4 hours), which automatically switches to power supply when the main power is interrupted, ensuring operation even when the power is cut off during a fire.

Lightweight design: Single unit weight ≤300kg (50m³/h model), 25% lighter than centrifugal pumps of the same flow, suitable for installation in narrow spaces such as decks and engine room tops.

IV. Typical Application Scenarios

1. Ship Area Fire Fighting

Engine room fires: When an oil fire occurs in the engine room of a cargo ship, a stainless steel ejector fire pump (flow 100m³/h, pressure 2.5MPa) sprays foam mixture through a fire monitor to cover equipment such as the main engine and generator, controlling the fire within 3 minutes.

Passenger cabin fires: When a fire breaks out in the living area of a passenger ship, a bronze alloy fire pump (flow 50m³/h, pressure 1.6MPa) drives the sprinkler system, forming a water curtain through ceiling sprinklers to prevent the fire from spreading to adjacent cabins.

2. Deck and Cargo Hold Fire Fighting

Container ship cargo holds: When containers catch fire, an ejector fire pump (flow 150m³/h, pressure 3.0MPa) sprays into the hold through a telescopic fire monitor, and the jet can penetrate container gaps to directly reach the fire source.

Oil tanker decks: When a leak and fire occur on the deck of an oil tanker, an explosion-proof stainless steel pump (flow 80m³/h) sprays seawater to cool the deck, and cooperates with a foam system to isolate oxygen, preventing the fire from spreading to the cargo oil tanks.

3. Emergency Rescue Scenarios

Maritime search and rescue: As auxiliary rescue equipment, it can use the water flow generated by the ejector pump to clear obstacles around lifeboats or deliver freshwater to distressed personnel (after filtration).

Deck cleaning: It can be used for cleaning deck oil stains when there is no fire (pressure adjusted to 0.5MPa), serving dual purposes and improving equipment utilization.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Ship type: Cast iron pumps for inland ships; bronze alloy pumps for coastal passenger ships and cargo ships; stainless steel pumps for ocean-going oil tankers and chemical tankers

Flow calculation: Configure according to the maximum cabin area of the ship (flow ≥0.1m³/h per m²), e.g., a 5000m² cargo hold requires flow ≥500m³/h

Pressure requirements: High-pressure models (2.5-4.0MPa) for engine rooms and high-rise areas; low-pressure models (1.0-2.5MPa) for decks and low-rise areas

2. Maintenance Points

Daily inspection: Manually start once a week (run for 5 minutes), check outlet pressure (fluctuation ≤±0.1MPa) and whether there is leakage to ensure availability in emergencies

Regular maintenance: Replace mechanical seals (oil-resistant fluororubber material) every 1000 hours, clean the inlet filter (to prevent blockage by seaweed and debris)

Annual inspection: Pass classification society inspection every year, test self-priming performance, explosion-proof performance, and linkage response speed to ensure compliance with SOLAS conventions

VI. Compliance and Certification

International standards: Complies with the requirements for fire equipment in Chapter II-2 of the IMO SOLAS Convention and ISO 14520 fire pump performance standards

Classification society certifications: Obtained type approval for fire pumps from RS, LR, ABS, CCS, and DNV (including 1000-hour seawater operation tests)

Domestic specifications: Meets the requirements of GB/T 6245 Fire Pumps and Technical Rules for Statutory Survey of Seagoing Ships Sailing in Domestic Waters for fire equipment