Cast Iron Ejector Cooling Pump

I. Product Overview

Marine cast iron ejector cooling pumps are high-efficiency heat exchange devices designed for marine cooling systems, using gray cast iron (HT250) or ductile iron (QT400-18) as the main material, and realizing the forced circulation of seawater, fresh water, or cooling liquids based on the ejector pump principle (Venturi effect). The core principle is that high-pressure working water flows through a nozzle to form a high-speed jet, creating vacuum negative pressure in the suction chamber to draw in cooling media and transport them through a diffuser to the heat exchange systems of engines, generators, and other equipment. After surface Ni-P alloy plating (thickness 25-35μm), the cast iron material can operate stably in seawater with Cl⁻≤20,000ppm, suitable for marine main engine cooling, auxiliary machine heat dissipation, and air conditioning systems, meeting IMO maritime regulations and classification society (CCS/ABS/DNV) certification requirements.

II. Core Technologies and Material Characteristics

1.Cast Iron Material Selection and Performance

2.Key Technical Parameters

Flow range: 20-300m³/h, suitable for ships of 1,000-20,000 tons

Head: 10-25m, self-priming height ≥6m (no priming required)

Heat exchange efficiency: Ejector cooling efficiency ≥68%, 10%-15% higher than traditional centrifugal pumps

Corrosion resistance design: Cast iron surface treated with zinc-based epoxy coating, passing 2,000-hour salt spray test (GB/T 10125) without corrosion

III. Technical Advantages and Innovative Design

1. Anti-Clogging and High-Efficiency Heat Exchange

Non-Rotating Component Design: Ejector pumps have no rotating parts such as impellers or shafts, capable of passing ≤3mm solid particles (such as marine organisms, rust), reducing clogging risk by 80% compared to centrifugal pumps, suitable for cooling media with impurities.

Enhanced Heat Exchange Structure: The diffuser adopts a gradually expanding design (cone angle 8°-12°), optimizing the water flow velocity gradient, increasing the heat transfer coefficient by 20%, and limiting equipment temperature rise to ≤35℃.

2. Marine Condition Adaptability

Anti-Tilt Performance: Stable water supply under ship trim 15° and list 10°, adapting to ship swaying environments and ensuring continuous operation of the cooling system.

Low Noise Design: Operation noise ≤70dB (at 1,500rpm), 10dB lower than traditional pumps, meeting passenger ship comfort requirements.

3. Convenient Maintenance and Cost Advantage

No-Disassembly Cleaning: Smooth flow channel (roughness Ra≤12.5μm), scaling rate 60% lower than centrifugal pumps, reducing annual cleaning frequency by 40%.

Cast Iron Cost Advantage: Overall cost is 30%-50% lower than stainless steel ejector pumps, suitable for mass installation on ships, with 50% lower maintenance costs.

IV. Typical Application Scenarios

1. Marine Main Engine Cooling

Diesel Engine Cooling: QT400-18 ejector pumps provide seawater cooling for ocean-going cargo ship main engines, flow 150-250m³/h, combined with plate heat exchangers to control cylinder liner temperature at 80-90℃.

Gas Turbine Cooling: Gray cast iron ejector pumps transport fresh water to the gas turbine lubrication system, self-priming height 7m, adapting to multi-deck engine room layouts.

2. Auxiliary Machine and Equipment Heat Dissipation

Generator Cooling: HT250 ejector pumps provide fresh water cooling for marine generators, flow 50-100m³/h, controlling winding temperature ≤120℃.

Hydraulic System Heat Dissipation: Ejector pumps 联动 with oil coolers to dissipate heat for deck machinery hydraulic systems, controlling oil temperature at 40-60℃.

3. Air Conditioning and Special Systems

Central Air Conditioning Cooling: QT400-18 ejector pumps transport seawater to air conditioning condensers, flow 80-150m³/h, condensing temperature ≤45℃.

LNG Ship Low-Temperature Cooling: Ductile iron ejector pumps transport -10℃ low-temperature ethylene glycol solution, combined with insulated pipelines to cool LNG pump cabin equipment.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Cooling Medium: Choose HT250 for fresh water, QT400-18 for seawater

Ship Tonnage: Select HT250 for <10,000 tons, QT400-18 for ≥10,000 tons

Flow Matching: Configure at 1.2 times the equipment heat dissipation, e.g., 5,000kW main engine recommends flow 180-220m³/h

2. Maintenance Points

Daily Monitoring: Check nozzle wear (allowable diameter wear ≤0.3mm) and inlet/outlet pressure (deviation ≤±5%) daily

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

Anti-Corrosion Maintenance: Reapply epoxy zinc-rich primer every two years (dry film thickness ≥150μm), install zinc sacrificial anodes for seawater systems

VI. Compliance and Certification

International Standards: Complies with IMO MSC.302(87) Code for Ventilation and Air Conditioning of Machinery Spaces on Ships

Classification Society Certification: Passed CCS Rules for the Classification of Steel Ships and ABS Rules for Building and Classing Ships

Environmental Requirements: Oil content in cooling water ≤15ppm, complying with MARPOL Annex I anti-pollution standards