SIEMENS Motor Snail Blower 6KV 10KV Flue Gas Fan

This article's table of contents introduction:

1. Nomenclature Breakdown
2. Typical Configuration & Application
3. Key Motor Specifications (Siemens Typical)
4. Common Problems & Troubleshooting
5. Recommended Actions for Procurement or Maintenance
6. Summary

This sounds like a request for information regarding a Siemens motor powering a snail blower (also known as a centrifugal fan or squirrel cage blower) used as a Flue Gas Fan in a power plant or industrial furnace, operating at high voltages (6kV or 10kV).

Here is a breakdown of what this combination typically entails, the specifications you need to look for, and common issues associated with this equipment.

Nomenclature Breakdown

• SIEMENS: The motor manufacturer (likely the 1LA8, 1LA9, or 1RN series for medium-voltage applications).
• Motor Snail Blower: This is a mis-translation or industry term for a Centrifugal Fan (the housing looks like a snail shell). The motor drives the impeller inside this "snail" housing.
• 6KV / 10KV: The rated voltage of the stator winding. 6kV is common in older European and Asian systems; 10kV is standard in newer or high-efficiency Chinese/Indian designs.
• Flue Gas Fan: The specific application. This fan handles hot, corrosive, and dusty exhaust gases (from boilers, furnaces, or kilns).

Typical Configuration & Application

• Function: To remove flue gases from a boiler or furnace, pulling them through scrubbers, electrostatic precipitators (ESPs), and out the chimney.
• Fan Type: Usually a Radial / Centrifugal type (the "snail").
  • Forced Draft (FD) Fan: Pushes air into the furnace.
  • Induced Draft (ID) Fan: Pulls flue gas out of the furnace. Given the mention of "Flue Gas", this is almost certainly an ID Fan.
• Challenges:
  • High Temperature: Gases can be >200°C. Bearings and motor cooling are critical.
  • Abrasion: Fly ash particles erode the impeller blades.
  • Corrosion: Sulfur oxides in the gas can form acid if the temperature drops below the dew point.

Key Motor Specifications (Siemens Typical)

If you are ordering or troubleshooting this motor, you need to verify these parameters:

Common Problems & Troubleshooting

When dealing with a high-voltage flue gas fan motor, these are the top failure modes:

A. Bearing Failure (Most Common)

• Cause: Heat soak from the hot flue gas traveling down the shaft, misalignment, or grease starvation.
• Sign: Vibration increase (especially axial), loud bearing noise.
• Fix: Use high-temperature grease; check shaft alignment; ensure cooling fan on motor is working.

B. Rotor Bar / End Ring Issues

• Cause: Frequent starting under heavy load (high inertia of the fan impeller).
• Sign: Current fluctuations, low starting torque, vibration at 2x line frequency.
• Fix: Use "soft start" or VFD to reduce starting stress.

C. Winding Insulation Breakdown

• Cause: Humidity, dust (conductive fly ash), or partial discharge in 10kV systems.
• Sign: Low insulation resistance (Megger test), leakage current, earth fault trip.
• Fix: Insulation wash (if dust), drying (IR lamps), or VPI (Vacuum Pressure Impregnation) rewind.

D. Impeller Wear (Snail Blower side)

• Cause: Erosion by fly ash.
• Sign: High vibration (unbalance), reduced airflow/pressure.
• Fix: Apply hard-facing (tungsten carbide) to leading edges; regular cleaning to prevent dust buildup.

Recommended Actions for Procurement or Maintenance

If you need to purchase or repair this system, ask for these details:

1. Siemens Type Designation: (e.g., 1LA8153-6AA...) - This contains all winding and mechanical details.
2. Thermal Protection: Does it have RTDs (Pt100) in the stator and bearings? (Critical for flue gas applications).
3. Shaft Sealing: How is the motor shaft sealed from the hot, dusty flue gas entering the motor? (Labyrinth seal, carbon ring, or purge air).
4. Cooling Type:
   • IC 01: Self-ventilated (OK for clean air).
   • IC 666: Separate forced cooling (better for variable speed or hot environments).
5. Space Heaters: Are anti-condensation heaters included (essential to prevent moisture during downtime)?

Summary

The SIEMENS Motor Snail Blower 6KV 10KV Flue Gas Fan is a heavy-duty, high-voltage centrifugal fan system used to extract hot, dirty exhaust gases. The motor is subject to high thermal stress, erosion, and electrical stress due to the high voltage and harsh environment. Bearing health, insulation integrity, and impeller balance are the three critical maintenance points.

For a precise quote or technical data sheet, you will need the "Order No." or "FG No." (Factory Number) from the motor nameplate.