This article's table of contents introduction:
- What is an "Overhang Type" Centrifugal Fan?
- Key Characteristics of a Mine Centrifugal Fan (High Pressure)
- Typical Specifications (Example)
- Common Models / Series Names (for context)
- Important Safety Note for Mining
- Summary
It sounds like you are looking for information or a specification for a Mine Centrifugal Ventilation Fan, specifically a High-Pressure Blower Fan of the Overhang Type.
This is a very specific piece of heavy industrial equipment used primarily in underground mining (coal, metal, or tunnel construction).
Here is a detailed breakdown of what this description means, its common applications, and typical specifications.
What is an "Overhang Type" Centrifugal Fan?
The term "Overhang Type" (also known as "Overhung" or "Cantilevered") refers to the mechanical arrangement of the impeller on the shaft.
- Standard Design: In an overhung fan, the impeller is mounted on the end of the drive shaft, "overhanging" beyond the bearing support. This is the most common design for centrifugal fans up to a certain size.
- Alternative (In-Between): In a "between-bearing" design (or "center hung"), the impeller is located between two bearings.
Key Advantages of Overhang Type for Mine Fans:
- Simpler Maintenance: The bearings and drive system are easily accessible. In a mine environment, this is critical.
- Lower Cost: Generally less expensive than between-bearing designs for medium-duty applications.
- Compact Footprint: Useful for tight spaces in underground tunnels and drifts.
Key Characteristics of a Mine Centrifugal Fan (High Pressure)
Mine fans are built differently than standard HVAC fans due to harsh operating conditions.
-
High Static Pressure (High Pressure Blower Fan):
- These fans must overcome the resistance (pressure drop) of long duct runs, duct leakage, and friction in the mine workings.
- They are designed to generate high static pressure (e.g., 1000 Pa to 10,000+ Pa / 4 inches w.g. to 40+ inches w.g.) at moderate to low airflow.
-
Rugged Construction:
- Housing: Heavy-gauge steel, often with stiffening ribs (flanged housing). Designed to withstand high pressure.
- Impeller: Robust, often backward-curved or radial-bladed (radial tip) impellers made of thick steel or abrasion-resistant material.
- Shaft & Bearings: Heavy-duty shaft and pillow-block bearings (or sealed cartridge bearings) designed for continuous 24/7 operation.
-
Application:
- Primary Mine Ventilation: As the main fan on a shaft or ventilation raise.
- Auxiliary Ventilation: Boosting airflow in dead-end tunnels (headings).
- Explosion-Proof Design (Mandatory for Coal Mines): Must be constructed so that sparks from the impeller or static electricity cannot ignite methane gas. This includes spark-resistant (non-ferrous) impeller tips or anti-static belts.
Typical Specifications (Example)
If you are searching for a specific product or writing a purchase order, you will need these parameters:
| Parameter | Typical Value / Range | Notes |
|---|---|---|
| Type | Centrifugal, Overhung (Overhang) | Also called "Overhung Impeller" (OHI) |
| Impeller Design | Backward Inclined (BI) or Radial (R) | BI for higher efficiency; Radial for high pressure & abrasion resistance |
| Airflow (Volume) | 5,000 m³/h to 500,000 m³/h (3,000 CFM to 300,000 CFM) | Depends on mine size |
| Static Pressure | 1,000 Pa to 10,000 Pa (4" w.g. to 40" w.g.) | High pressure is key |
| Motor | Direct Drive (coupling) or Belt Drive | Belt drive allows speed adjustment via pulley change |
| Material | Steel, Stainless Steel (for corrosion), or Anti-Spark | Coal mines require anti-spark (aluminum/brass impeller tips) |
| Standards | ISO 5801 (fan performance), ATEX / IECEx (explosion-proof) | Mandatory for underground use |
Common Models / Series Names (for context)
Manufacturers often give these fans model numbers like:
- K-Series (Krebbs / centrifugal mine fans)
- M-Series (Mine ventilation)
- High-Pressure Centrifugal Fan (HPCF)
- Explosion-Proof Auxiliary Fan (EPAF)
- Overhung Centrifugal Fan (OHCF)
Important Safety Note for Mining
If this is for a coal mine (gassy mine), the fan MUST be:
- ATEX Certified (Category M1 or M2) or IECEx Certified.
- Anti-Spark: The impeller must be made of non-ferrous material (aluminum, brass, or special plastic) or have non-sparking inserts.
- Equipped with a Ventilation Monitoring System (for airflow, vibration, and temperature).
Summary
To order or identify the correct Mine Centrifugal Ventilation Fan - High Pressure - Overhang Type, you need to provide:
- Operating Point: (Required Airflow CFM/m³/s) and (Required Static Pressure in inches w.g. or Pascals).
- Gas Group: (Is the mine gassy? Explosion-proof required?).
- Mounting: (Horizontal or vertical? Shaft orientation?).
- Accessories: (Is a silencer, inlet box, or backdraft damper needed?).
Need a specific datasheet? If you have a model number or manufacturer name (e.g., "ABC Fan M30 Overhung"), please provide it, and I can help you find the specific technical drawing or performance curve.
