Learn working principle of bucket wheel stacker reclaimer

What is a bucket wheel stacker reclaimer?

Bucket wheel stacker and reclaimer refers to a high-efficiency loading and unloading machine used for continuous conveying of both stacking and reclaiming materials in large dry bulk storage yards. It is composed of a belt conveyor arm that can tilt and swing horizontally and its front bucket wheel, frame, and running mechanism. The belt can run in both directions. When reclaiming materials, the bucket wheel takes materials and sends them out through the conveying arm, and when stacking materials, the main conveyor is used. The delivered goods are sent to the yard via the conveying arm.

How does the wheel stacker work?

There are two operation modes of bucket wheel stacker and reclaimer: stacker and reclaimer. The bulk material transported by the belt conveyor is unloaded by the tail truck to the belt conveyor on the boom and thrown to the yard from the front end of the boom. Through the operation of the whole machine, the rotation and pitch of the boom can make the material pile form a regular trapezoidal cross-sectional shape. Through the rotation of the boom and the rotation of the bucket wheel, material reclaiming is realized continuously. The material is discharged to the belt conveyor with arm support through the discharge plate, and then to the belt conveyor of the material yard through the hopper under the center of the machine. Through the operation of the whole machine and the rotation and pitch of the boom, the bucket wheel can remove all the material in the storage pile.

1. The slope reclaiming method refers to the working method in which the bucket wheel rotates from top to bottom along the slope of the stockpile according to a given feed speed. Because the material has a natural stacking angle (angle of repose), the trolley backs up a certain distance each time the boom is lowered. When the reclaimed material reaches the required reclaiming depth, the travel mechanism moves forward another bucket depth, raising the boom together to reclaim the material on the second slope.

2. The horizontal full-layer reclaim method treats the height of all material stacks as consisting of multiple layers of material. The bucket wheel stacker reclaimer uses the same rotation + walking method (in rotation, when the picking angle is greater than 30 degrees, it can jog a distance to compensate for the loss of the crescent during the picking process). During reclaiming, the first layer of material is taken over the entire length of the pile with the boom held at the same height. The cart is then returned to the same initial orientation and a second layer of material is taken. This is a method with high working power, which can prevent the occurrence of pressure barrel accidents caused by collapse during work. In the actual reclaiming process, the entire length of the material stack can also be divided into several sections as needed. This method can be called segmented layered rotary reclaiming.

Components of refurbished bucket wheel stacker and reclaimer

The boom type bucket wheel stacker and reclaimer is composed of a bucket wheel mechanism, a slewing mechanism, a belt conveyor, a tail car, a pitching and running mechanism.

1. Bucket wheel mechanism: It is the working mechanism for reclaiming materials, including the bucket wheel and its driving device. The bucket wheel is divided into three types: unformatted, semi-formatted and formatted. The bucket without format bucket wheel has no bucket bottom. In the non-discharge area, the arc baffle fixed on the boom is used to block the bulk material in the bucket, and the bulk material slides on the arc baffle. There is no arc baffle in the discharge area but a fixed chute. When the bucket rotates with the wheel body to the discharge area, the material in the bucket slides to the belt conveyor through the inclined chute under the action of its own weight. It has a large unloading interval, so the bucket wheel rotates at a higher speed, which can improve the working capacity and can unload sticky materials. The structure of the half-format bucket wheel is similar to that of the plain bucket wheel, except that the bucket wall is extended to the center of the bucket wheel to increase the distance between the arc baffle and the wheel body to reduce the occurrence of material jamming between the arc baffle and the wheel body. The bottom of each bucket of the format bucket wheel is a fan-shaped inclined chute, but there is a fixed side baffle in the non-discharge area. When the bucket rotates with the wheel body to a certain height, the bulk material in the bucket begins to slide along the fan-shaped inclined chute towards the center of the bucket wheel. The board slides onto the belt conveyor. The regular bucket wheel discharges slowly, requires a larger diameter of the bucket wheel, but does not cause material jamming, and is suitable for hard materials. Among the three bucket wheels, the plain format is the most used. There are two transmission modes of bucket wheel, mechanical and hydraulic, generally without speed regulation.

2. Slewing mechanism: It consists of two parts, a slewing bearing and a driving device, which are used to make the boom slew left and right. In order to ensure that the bucket shovel can be fully filled when the boom is in any position, the rotation speed is required to be within the range of 0.01 to 0.2 r/min to achieve automatic stepless adjustment according to a certain law. Most of them are driven by DC motors or hydraulics.

3. Boom belt conveyor: for conveying materials. When stacking and reclaiming materials, the conveyor belt needs to run forward and reverse.

4. Tail car: The mechanism that links the material yard belt conveyor with the bucket wheel stacker and reclaimer. The conveyor belt of the material yard belt conveyor bypasses the two rollers on the tail car frame and runs in an S shape, so that the material can be transferred from the material yard belt conveyor to the bucket wheel stacker and reclaimer when stacking.

5. The pitching mechanism and the running mechanism are similar to the corresponding mechanism in the portal crane.