BASICS IN STACKER RECLAIMER

In the previous article (titled ‘Reclaim Mode Drawing and Case Study on YouTube Video’), a question has been asked along with a photograph. For your convenience the same is mentioned below: Although it is possible for the operator to reclaim (in manual mode) the material from the stockyard as shown in the below photo, IT IS NOT ALLOWED to do so. ‘WHY IT IS NOT ALLOWED’? It has been explained in the previous article that the reclaim operation has to be started only from the EDGE of the stockpile. Whereas in the above photo, the reclaim operation has been started from the mid of the stockpile by the operator. That’s why instead of a CONCAVE CURVE, we see a CONVEX CURVE on the stockpile. For more clarity refer the below 3D models. 1.    Stockpile 2. Forward cut reclaiming operation (GENERAL PRACTICE) in which the reclaiming operation started from the edge of the stockpile. 3. Reverse/Middle cut reclaiming operation (NOT ALLOWED) in which the reclaim...

I’ve seen an animation in the YouTube on reclaiming operation by a bucket wheel reclaimer machine. The animation is very good, but the reclaimed portion of the stockpile is not represented correctly in the animation. Before looking into this, I just want to explain THE RECLAIM MODE DRAWING ie., HOW A BUCKET WHEEL STACKER CUM RECLAIMER RECLAIMS THE STACKED MATERIAL FROM THE STOCKPILE. This will make you to understand the wrong representation of the reclaimed stockpile portion in that animation. (It is not ethical to give the YouTube video/link in this blog, since the YouTube video contains the company logo also. For your reference, I’ve just shown the screen shot from the video WITHOUT the company logo) Consider the stockpile (& other parameters) we have discussed in one of the previous articles (titled “Trapezoidal stockpile Vs Trapezoidal stockpile”). Machine                  ...

In the article titled ‘Undercarriage support structure’ we have discussed that we have to provide a 3/3 undercarriage support for the machine which is operating on an offset yard conveyor. Now the question is, "is it possible to provide a 3/4 undercarriage support instead of a 3/3 undercarriage support for a machine which is operating on an offset yard conveyor"? The answer is ‘YES’. Design a Bucket Wheel Stacker cum Reclaimer machine with a 3/4 undercarriage support which is working on a conveyor which is offset with the axis of the machine. SOLUTION: By providing a 3/4 undercarriage support we will face the following problems, 1. Feeding the material to the yard conveyor during reclaiming operation. 2. Feeding the material to the boom conveyor during stacking operation. 3. Feeding the material to the intermediate conveyor during stacking operation. Let us discuss the solution in 3 parts. a. Undercarriage WITH inclined chute. b. Interme...

It is through the undercarriage the load (of the machine) is distributed to the wheel bogies and to the civil foundation through rails. Undercarriage support structure is designed to transmit the forces to the tracks (through 3 points or 4 points). A 3-point structure may be designed as a 3/3 system or a 3/4 system, whereas a 4-point structure is always designed as 4/4 system. 3/3 & 3/4 support undercarriage: The undercarriage support structure shall designed as a 3/3 support or a 3/4 support based on the system requirement. If the conveyor is offset with the machine axis (or in some cases if there are 2 conveyors between the rails) then the machine shall be provided with 3/3 support undercarriage. If the conveyor is in line with the machine axis then the machine shall be provided with 3/4 support under carriage.   4/4 support undercarriage: If the conveyor is in line with the machine axis then 4/4 support undercar...

Consistency is an important and inevitable factor in any process plant. To meet a consistent quality output of the product (for example steel or cement) the raw material shall be fed continuously for processing in the required ratio. Consider a case in which the raw materials are stored in the stockyard in number of layers and during reclaiming if the consistency in blending is disturbed after sometime of reclaiming. The result will be change in product quality. Case study: Form a stockpile of 40m (Width) x 12m (Height) x 250m (Length) with 6 layers and discuss the consistency (mixture of all 6 layers of material) during reclaiming operation. Machines used for stacking & reclaiming, Stacker       - Luffing Stacker or Twin Boom Stacker Reclaimer   - Bridge Scrapper Reclaimer or Barrel Reclaimer or Wheel on Bridge Reclaimer (Note: above mentioned reclaimers are with harrow arrangement) STOCKPILE: Below sketch shows a stockpile of 40...

Trapezoidal stockpile can be formed in the following two methods, 1.    Without compensating the travel length of the machine. 2.    By compensating the travel length of the machine. Each method has its own advantage and disadvantage. Before comparing the advantages and disadvantages, let us discuss how a trapezoidal stockpile is formed. Without compensating the travel length of the machine: The above figure(s) shows a trapezoidal stockpile formed without compensating the travel length of the machine. By compensating the travel length of the machine: The above figure shows a trapezoidal stockpile formed by  compensating  the travel length of the machine. Travel length compensation: To understand travel length compensation, first let us discuss how a triangular stockpile is formed with the help of a stacking mode drawing. (Stacking mode drawing: Is the drawing which defines the slewing angle, luffing angle and t...