Weigh feeder is a closed-loop control system, which controls the flow of material very accurately using controller and different instruments. This system accepts an external command from process computers like SCADA, HMI, DCS etc.
The instrument used in this system to control the flow rate is Closed-loop control with panels, Load cell to measure the weight of a predefined area on the belt and Encoder to measure the speed of the belt, AC Drive to control the speed of the motor which is connected on the gear box to drive the conveyor belt.
The closed-loop controller is a micro controller-based instrument which can be programmed according to user requirement. Basically, it gets signals from load cell and encoder, these two signals are converted according to field instrument rating and then multiplied together to get the current rate of flow.
This rate of flow is used to control the set flow which is given in the controller by using external controller or process computer. Also, there is a facility to generate the alarm or error if field environment is outside the given parameter.
The controller accepts a set flow rate via electrical signal which is 4-20 mA and also give an output flow rate is the same electrical signal. Controller also gives an electrical signal to control the speed of the motor through the AC drive according to set flow rate.
There are normally four strain gauges that are bonded in the Wheatstone bridge configuration. The input supply to the load cell is in Volts and also known as excitation voltage. The output of the load cell is in mili Volts.
This consists of a proximity type speed sensor, which is triggered by a disc mounted inside the tacho generator. Generally, the input of this sensor is in Volts and the output is in frequency with fixed amplitude.
PEL manufactures microprocessor based digital weigh feeders as per design of HASLER International-France, incorporating their state-of-the-art technology for continuous control and proportioning application in cement, steel, fertilizer, chemicals, petrochemical and other industries.
Rotor Weigh Feeder is mainly applied for continuous gravimetric weighing of pulverized coal in the cement calcination process. The process of coal discharging, weighing and conveying to pneumatic transmission pipe is all finished in this enclosed structure.
It adopts the operation principle of the rotor by gravity force. Bulk material is discharged from the bunker through rotor, brought to weighing area, and then sent to the pneumatic transmission pipe after measurement and at last sent to the process by the air from the air fan. The weighing shaft passes through the outlet of the material and the disconnectable coupling between pneumatic pipe and rotor which means that it can compensate the secondary load reaction caused by pressure fluctuation and do not influence the material measurement results. Whenever the material passes the weighing area, its weight will be measured by weighing device. Material weight and position are all stored in the electronic system of the feeder, namely, the load condition of every part of the rotor has been got before the discharge. In order to make the pre-setting value match the material quantity stored in the storage house, angular velocity of rotor required in the discharge position has been calculated and finished by the rotor driving device. Through this pre-control principle, the rotor weighfeeder can calibrate any fluctuation and offer high accuracy.
HASLER equipment ensures unparalleled accuracy and reliability, helping you make your production center profitable. So you will take advantage of our machines, our know-how, and the agile approach of our company on a human scale. Continuous dosing, constant measurement of feed rates and mixing of materials; Constant measurement of the weighing of raw materials and pulverized coal in the furnace. From the reception of the raw material in the factory to the dispatch of bag or bulk cement, the manufacturing process is strictly controlled according to very strict international standards.
Apron extractor Weigh feeders are used for difficult products to extract, in the ore crushing workshop or for coke ovens. HASLER Groups range of equipment allow theflowmeasurement anddosing of raw materials such as pellets, clinker and limestone or coal .
Each weigh feeder needs a system of regulation in order to respect the instruction of flow. These regulators PID (Proportional Integral and Derivative) function uninterrupted or in batch. They are integrated in cases guarantors to the standards of insulation and etancheity. The consoles of control and dialogue facilitate the man-machine interfaces.
For easy installation into 3rd party conveyors built for rugged use and outdoor environment such as quarries, gravel processing, mining, cement, fertilizer and chemical processing plants. Our range of belt scales is composed of Smart Belt Scale (SBS), Large Belt Scale (LBS), for belt conveyors, and Smart Apron Scale (SAS), for apron conveyors.
High accurate electronic load cells determine the weight. The weighbridge is a prefabricated concrete or steel unit. On request, it can, however, also be cast in situ according to oour drawings and statics.