is there any different from drag chain conveyor and scraper conveyor?

Yes, there are distinct differences between drag chain conveyors and scraper conveyors:

### Drag Chain Conveyors:
- **Design**: Features one or more chains that drag materials along a trough.
- **Material Handling**: Commonly used for bulk materials like grains, pellets, or heavy materials.
- **Operation**: The chains pull material through a closed system, minimizing spillage and allowing for gentle handling.
- **Applications**: Often found in industries like agriculture, mining, and recycling.

### Scraper Conveyors:
- **Design**: Utilizes a series of scrapers attached to a chain that moves along a trough.
- **Material Handling**: Suitable for transporting smaller materials, such as sludge or scrap, and can handle various shapes.
- **Operation**: The scrapers push the material along the bottom of the trough, which can be less gentle than drag chain systems.
- **Applications**: Commonly used in wastewater treatment, manufacturing, and material recovery operations.

### Key Differences:
- **Mechanism**: Drag chain conveyors pull materials, while scraper conveyors push them.
- **Material Types**: Drag chain conveyors typically handle heavier, bulk materials; scraper conveyors are more versatile for lighter, irregular materials.
- **Design and Maintenance**: The design differences can also affect maintenance requirements and operational efficiency depending on the material being moved.

These factors determine which type is more suitable for a given application.