INDUSTRY: Coal,Coke,Dolomite ,Limestone ,Utilities (Power Plants)
WHERE THEY ARE USED: Rotary Samplers are used mainly in the coal industry to acquire samples of coal from a continuously moving conveyor belt. They are often located at Conveyor Gallery ,rail or barge loading facilities. Samples are used to check or guarantee product analysis. Air is usually not available at these locations, so electrically actuated units are required. HOW THEY WORK: The sampler is a large round scoop which rotates one revolution per cycle perpendicular to the coal flow. It cuts a swath through the coal and throws a sample into a chute. The coal sample is taken via the chute to the analysis equipment. The high inertia scoop must be accelerated to full speed within 90 degrees rotation to insure it will have enough power to cut through the coal as it travels along the conveyor belt. The scoop must be stopped within approximately 30 degrees rotation after it has passed through the coal. The cycle rate can vary from one every few minutes to three cycles per minute. The sample scoop rotation speed is determined by the conveyor belt speed. On high-speed narrow belts, the scoop rotation speed gets very high, requiring quick actuation, and short accel/decel times.
PROBLEMS SOLVED: 1. Compressed air was not available; therefore an electric actuation system was developed and implemented with great success. 2. The high-speed actuation system brought the sampler scoop up to speed within the required 90
degrees rotation. It was also able to stop the wheel quickly after leaving the coal so that full power
3. This is a continuous process with limited time for loading. The long-term reliability of such system IMPORTANT FEATURES: Totally enclosed, sealed design eliminates problems associated with dust, dirt, water, or other contaminants. Electric actuation system provides quick engagements and simple regulation of torque and accel/decel rates.
Advantage :
- It can be easily retrofitted in the conveyor without much modification and without any shut down of conveying system.
- Being a stand alone type , it offers minimum interference for existing structure and system .
- It can be designed to have less quantity of primary sample mass which in turn , requires less no. of equipments for sample division.
- Since the sample quantity is Less it can be easily handled.
- Sample of Coke can be collected from a moving conveyor.
- Since the samples does not stay inside, except during a single rotation of a rotary cutter it is at least subjected to abrasion and as such less maintenance prone.
- Due to cross cut sweep sampler guaranteed representative samples can be collected for product analysis.
- Rotation Speed of samples can be predetermined and it is adjustable also.
- Totally Enclosed sealed designed eliminates problems associated with dust, dirt, or other contaminants.
- Can operate by pressing a single on/off switch.
- Reliable & maintenance free.
- Eliminates human error.
|
