150ZJ-50 Slurry Pump Anti‑Vortex Plate Design and Installation: Field Retrofit to Prevent Air Ingestion

Subtitle: Analysis of vortex air ingestion at low liquid levels and a practical anti‑vortex plate fabrication & installation solution

Introduction

In slurry pits, sumps, or tailings pump stations, the 150ZJ-50 slurry pump (150mm discharge, 500mm impeller diameter) often faces fluctuating liquid levels. When the level drops near the suction inlet, a funnel‑shaped vortex forms, drawing large amounts of air into the pump. This causes cavitation, vibration, flow instability, and even pump surging. Long‑term vortex air ingestion accelerates cavitation damage to the impeller and casing.

Installing an anti‑vortex plate is a low‑cost, highly reliable field retrofit. As a professional slurry pump manufacturer, this article explains the vortex formation mechanism and provides a complete design, fabrication, and installation guide for a 150ZJ-50 pump.

1. Hazards and Mechanism of Vortex Air Ingestion

1.1 Typical Hazards

1.2 Conditions for Vortex Formation

Vortices form easily when:

• Low liquid level: Submergence < 2× suction inlet diameter (for 150ZJ-50, suction ≈200mm, safe level ≥400mm)

• High suction velocity: Pump flow high, inlet velocity >1.5 m/s

• Irregular flow pattern: Recirculation or side inflow enhances vortex

2. Principle of Anti‑Vortex Plate

An anti‑vortex plate is a horizontal (or slightly inclined) flat plate installed directly below (or above) the pump suction inlet. It disrupts the vertical axial flow structure of the vortex. When liquid tries to form a vortex, the plate blocks the return path, forcing liquid to enter uniformly from all sides, thus eliminating air ingestion.

Key point: The plate is not a solid seal; it leaves enough flow area to ensure smooth suction.

3. Anti‑Vortex Plate Design for 150ZJ-50

3.1 Design Parameters

Based on the pump’s suction size and typical flow rate, recommended dimensions:

3.2 Shape Selection

• Square or round: Square is easier to fabricate; round gives more uniform flow. Recommend 300×300mm square.

• Perforated or solid: For slurries with fibers or large particles, use solid plate (flow passes around edges). For clean water or fine particles, small holes can reduce resistance.

3.3 Installation Position

The plate should be fixed horizontally directly below the suction inlet, at a distance of about 0.5D (≈100mm) from the bottom edge of the inlet. It can be welded or bolted to embedded parts or a dedicated bracket on the pit floor.

4. Field Fabrication and Installation Procedure

4.1 Material Preparation

4.2 Installation Steps

4.3 Validation After Retrofit

• No visible vortex at minimum operating level.

• Pump discharge pressure and current stable.

• Pump casing vibration significantly reduced.

5. Case Study: Vortex Retrofit at a Concentrator

Background: A tailings pump station with a 150ZJ-50 pump often had liquid level as low as 300mm (suction D=200mm). A clear vortex was visible, and the impeller needed replacement every 3 months due to severe cavitation.

Retrofit: Installed a 350×350×10mm anti‑vortex plate at 120mm below suction.

Results:

• Vortex completely eliminated.

• Vibration dropped from 5.2 mm/s to 2.1 mm/s.

• Impeller life extended to 9 months.

• Annual spare parts savings ≈ $1,500 (USD).

6. Troubleshooting and Common Issues

Conclusion

Vortex air ingestion during low‑level operation is a common cause of cavitation, vibration, and performance loss in 150ZJ-50 slurry pumps. Installing an anti‑vortex plate is a simple, low‑cost, and highly effective field retrofit. Using the design dimensions (300×300mm, 100mm clearance) and installation steps provided, most vortex problems can be solved.

As a professional slurry pump manufacturer, we recommend incorporating anti‑vortex plate mounting provisions when designing new pump pits, or retrofitting existing pumps. For custom anti‑vortex plates or on‑site guidance, please contact our technical team.