In bottom ash handling systems, several types of conveyors are used to transport the coarse, granular material that remains after waste combustion. The choice of conveyor depends on the characteristics of the bottom ash, such as its size, weight, and abrasiveness, as well as the layout and capacity requirements of the plant. Here are the most commonly used types of conveyors for bottom ash handling:
### 1. **Chain Drag Conveyors**
- **Description**: Chain drag conveyors use a chain with flights or paddles to drag bottom ash along a trough or enclosed casing. They are robust and well-suited for handling heavy and abrasive materials.
- **Advantages**: They can handle large volumes of coarse ash and are effective for transporting material horizontally or on a slight incline. They are also enclosed, which helps in controlling dust and spillage.
### 2. **Apron Conveyors**
- **Description**: Apron conveyors have a series of overlapping metal plates or pans attached to a chain. These plates form a continuous surface that transports bottom ash.
- **Advantages**: Apron conveyors are durable and can handle heavy, abrasive materials. They are effective for horizontal and inclined transport and can handle larger lumps of ash without significant degradation.
### 3. **Screw Conveyors (Auger Conveyors)**
- **Description**: Screw conveyors use a rotating helical screw blade (auger) within a tube to move materials along the conveyor. They are also used for bottom ash handling, particularly for smaller or finer particles.
- **Advantages**: Screw conveyors are versatile and can be configured for horizontal, inclined, or vertical transport. They are suitable for handling bulk materials and can manage variations in ash size and composition.
### 4. **Bucket Elevators**
- **Description**: Bucket elevators use a series of buckets attached to a belt or chain to lift bottom ash vertically from lower to higher elevations.
- **Advantages**: They are ideal for vertical transport of bottom ash, especially when moving material to a different level in the plant. Bucket elevators are efficient for handling large quantities of material and can handle coarse ash.
### 5. **Conveyor Belts**
- **Description**: Conveyor belts, specifically heavy-duty rubber or metal belts, can be used for transporting bottom ash. They are typically used for horizontal or slightly inclined transport.
- **Advantages**: Conveyor belts are flexible in terms of length and configuration. They are suitable for handling bulk materials and can be equipped with various types of belt covers and cleaning systems to manage dust and spillage.
### 6. **Vibrating Conveyors**
- **Description**: Vibrating conveyors use oscillatory motion to move bottom ash along a trough or surface. The vibrations help to move the material forward.
- **Advantages**: Vibrating conveyors can handle coarse and abrasive materials and are suitable for applications where a gentle conveying action is needed. They can be used for horizontal or slight inclines.
### Selection Criteria
- **Material Characteristics**: Bottom ash is often coarse, abrasive, and heavy, so the conveyor system must be robust and capable of handling these properties.
- **Distance and Elevation**: Consider the required distance and vertical lift when choosing the conveyor type. Some conveyors are better suited for horizontal transport, while others are designed for vertical lifting.
- **Dust Control**: Enclosed or well-sealed conveyors help in managing dust and preventing spillage.
- **Capacity**: The conveyor system should be capable of handling the required volume of bottom ash efficiently.
- **Maintenance**: Durability and ease of maintenance are important, particularly because bottom ash can be abrasive and demanding on equipment.
Each type of conveyor system has its own advantages and is selected based on the specific requirements of the bottom ash handling system in the waste-to-energy plant.
Post time: Aug-30-2024