There are many different types of chain conveyors on the market, all of which start out with a continuous chain and fixed flights that operate within an enclosed trough. The word “drag” encompasses all styles such as scraper, paddle, or En-Masse because each type of conveyance moves the chain and product by dragging it forward.
The paddle drag conveyors work using push/pull to move the product. Although this can be effective, it does eliminate any available cross-sectional area within the trough to around 50%, while the En-Masse drag conveyor can use as much as 90% of the physical size of the conveyor for conveying. This means that the physical size of the paddle conveyor will be 50% larger than an En-Masse to carry the same amount of material.
The En-Masse drag conveyor has a single strand of endless chain to pull material through the conveyor. It is a very versatile conveying method because En-Masse drag conveyors are typically high torque/low speed which equates to longevity of the conveyor due to the minimum wear on the chain, and lower cost of operation due to low horsepower and therefore low power consumption, as well as little maintenance compared to other conveying types.
The standard paddle drag conveyor is designed with two endless strands of chain. This conveys using paddles to scrape material through the trough. Unlike the En-Masse drag conveyor, how much material the paddle drag conveyor moves is dependent on the cross sectional area of the paddle as well as the chain speed. Because of the two strands of chain in a paddle conveyor, the horsepower consumption is higher than in a single chain strand En-Masse drag conveyor, and therefore a higher cost of operation.
Each application is different and does require the right determination as to which drag chain conveyor will be the best fit due to the material and movement requirements.