Cast Steel Ejector Sewage Pump

I. Product Overview

Marine cast steel ejector sewage pumps are high-efficiency treatment equipment designed for ship sewage discharge systems, using ZG270-500 cast steel or ZG310-570 high-strength cast steel as the main material. Based on the ejector pump principle (Venturi effect), they enable rapid pumping and transportation of ship sewage (containing oil, solid particles, fibrous impurities, etc.). The working principle is that high-pressure water forms a high-speed jet through a cast steel nozzle, creating vacuum negative pressure in the suction chamber to draw in sewage, which is then pressurized by a diffuser and discharged, suitable for treating domestic sewage, engine room sewage, and cargo hold sewage. After quenching-tempering treatment and nano-ceramic coating reinforcement, the cast steel material can operate stably in seawater with Cl⁻≤25,000ppm and sewage with pH 5-10, meeting IMO MARPOL Annex IV anti-pollution conventions and international classification society certifications (LR, ABS, DNV, etc.), widely used in cargo ships, passenger ships, engineering vessels, and other scenarios.

II. Core Technologies and Material Characteristics

1.Cast Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 30-200m³/h, suitable for ships of 1,000-25,000 tons

Head: 15-40m, self-priming height ≥8m, no priming required at startup

Impurity passing capacity: Passes ≤10mm solid particles and ≤15mm fibrous impurities, clogging risk reduced by 98%

Structural strength: Cast steel components tested by magnetic particle inspection (MT), bearing 5x rated pressure

Corrosion resistance design: Nano-ceramic coating (thickness ≥350μm), passing 6,000-hour salt spray test without rust, 85% improved sewage erosion resistance

III. Technical Advantages and Innovative Design

1. Efficient Sewage Disposal and Anti-Clogging Capability

Non-rotating component design: Ejector pumps have no vulnerable parts such as impellers or shafts. Large-diameter flow channel design ensures smooth transport of sediment, rags, and other impurities in sewage, especially suitable for harsh conditions with complex impurities.

Intelligent backwash system: The suction chamber is equipped with an automatic backwash grille that starts high-pressure water backwashing when impurities accumulate, extending the maintenance cycle to 24 months.

2. Complex Condition Adaptability

All-attitude operation capability: Stable drainage under ship trim 25° and list 12°, adapting to ship swaying environments to ensure continuous operation of the sewage system.

Anti-winding structure: The diffuser inner wall adopts a spiral guide design to effectively intercept fibrous impurities, avoiding winding and clogging and improving system reliability.

3. Long Life and Convenient Maintenance

Wear-resistant reinforcement: Cast steel impeller surface treated by laser cladding tungsten carbide (thickness 250μm), 5x improved wear resistance, service life exceeding 30,000 hours.

Modular quick-release structure: Pump body and pipelines use flange quick-connect design, reducing single-component replacement time by 80% and maintenance costs by 50%.

IV. Typical Application Scenarios

1. Ship Domestic Sewage Treatment

Passenger ship sewage discharge: ZG270-500 cast steel pumps treat domestic sewage for cruise ships, flow 60-100m³/h, combined with domestic sewage treatment plants (STP) to meet IMO emission standards.

Crew toilet sewage discharge: Provides negative pressure pumping for multi-deck cabins, self-priming height 9m, avoiding odor accumulation and improving living comfort.

2. Engine Room and Cargo Hold Sewage

Engine room sewage pumping: ZG310-570 cast steel pumps extract oily sewage from engine rooms, flow 40-120m³/h, anti-oil film adhesion design to prevent clogging.

Cargo hold sewage emergency discharge: Rapid drainage in case of cargo hold flooding, combined with emergency drainage systems to meet SOLAS emergency requirements.

3. Special Ships and Offshore Platforms

Engineering ship sewage systems: Treat sediment-containing sewage for dredgers, passing ≤10mm sediment particles to ensure compliant sewage discharge during construction.

Offshore platform sewage: High-pressure ejector pumps (head ≥30m) treat platform domestic sewage and industrial wastewater, adapting to complex offshore conditions.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Sewage type: Choose ZG270-500 for domestic sewage, ZG310-570 for oily/particulate sewage

Ship tonnage: Select ZG270-500 for <10,000 tons, ZG310-570 for ≥10,000 tons

Flow matching: Configure at 2x maximum sewage generation, e.g., 5,000-ton cargo ships recommend flow 100-150m³/h

2. Maintenance Key Points

Daily monitoring: Real-time monitoring of inlet/outlet pressure and vacuum, ensuring pressure fluctuation ≤±10%

Regular maintenance: Clean suction grilles (accuracy ≤15mm) quarterly, remove pump cavity oil sludge with special cleaners annually

In-depth maintenance: Nondestructive testing every 3 years, reapply nano-ceramic coating, and inspect seal status

VI. Compliance and Certification

International standards: Complies with IMO MARPOL Annex IV Regulations for the Prevention of Pollution by Sewage from Ships

Classification society certifications: Passed LR Rules for the Classification of Ships and ABS Rules for Building and Classing Ships

Environmental requirements: Discharged water quality complies with GB 3552 Discharge Control Standard for Water Pollutants from Ships