18.07.2022

Weighing system

Currently, conveyor scales are widely used and play an important role in industries such as cement industry, thermal power, coal mining, ore, wood processing industry to calculate the output of products. through tape in production shifts, data storage and management, material dosing and mixing to create quality products according to production requirements. With technical strength and experience in the field of Control - Measurement - Automation, Thien Tan company is a supplier of solutions and weighing products of SIEMENS with the product line of conveyor scales, mixing scales. with high accuracy up to 0.25%.

Structure and principle of conveyor weighing, mixing balance

Quantitative conveyor weighing system is used to quantify the composition of raw materials, ensuring the proportion of ingredients for the manufactured product to meet the required quality. Product quality is stable, saving production and business costs.

Image. 1 Operation model of quantitative conveyor weighing

The quantitative conveyor weighing system is similar to the conveyor weighing system, except that the motor can change the speed to change the mass.

Image. 2 Actual models of Belt Scale quantitative conveyor scales

Weigh Belt Feeder/Belt Scale has an accuracy of ±0.25% to ±0.5% depending on the type of scale and the requirements of the production unit.

The main components of the quantitative conveyor weighing system include: Weighing head, force sensor, motor speed control inverter, speed monitoring sensor, band deviation monitoring sensor, motor, conveyor structure, .. With an initial setting weight (set point), the weighing system compares the weighing result (actual value) with the set value. If the actual mass is less than the set mass, the system will increase the engine speed until the set value is reached. If the result is greater then vice versa. 

Image. 3 Loadcell installation structure for quantitative conveyor Belt Scale

Operation: The Weight Belt Feeder/Belt Scale is designed to continuously weigh the amount of material being transported on a conveyor.

Conveyor load: Material is led to a pre-placed weighing platform under the conveyor and limited by 2 rollers (via 1 or more rollers fitted with a Force Sensor), the weighing platform exerts 1 force on the Sensor force

Solutions for using SIEMENS BELT SCALE conveyor scales in the cement, fertilizer and mining industries.

Realizing the potential of the field of quantitative weighing and its application is increasingly popular in the system from medium to large scale of factories and factories along with its strength in industrial measuring devices. Siemens offers a wide range of conveyor weighing products that allow working with high accuracy and low cost, widely applied in light and heavy industries under harsh conditions such as: Fertilizer, sand, coal, stone, iron and steel…

Components of SIEMENS . BELT SCALE conveyor system

A basic conveyor weighing system has the following components: A weighbridge with load cells, an integrator and a speed sensor. The loadcells (Force Sensors) will measure the weight of the material on the scale and send a signal to the integrator. This unit also receives electrical pulse signals from the speed sensor (mounted on the tail or bottom of the tape), the integrator will use these signals to calculate the material yield through the tape, using the formula: mass x speed degree = productivity.

Image. 4 SIEMENS . Belt Scale Model

Siemens Milltronics conveyor scales measure materials only when vertical pressure is applied. The material is poured onto the ice and moves on the conveyor through the weighbridge creating a force proportional to the amount of material transferred through the roller mounted on the load cells, the force acting on the load cells will be sensed by the sensor. Measure the tension inside the load cell. When the strain gauge sensor is excited by a voltage signal from the integrator, it responds by emitting an electrical signal proportional to the feed flow to the integrator.

Main product lines BELT SCALE of SIEMENS

Siemens Milltronics MLC: Use with low power range, suitable for monitoring products such as animal feed, tobacco, fertilizer or sugar. Compact stainless steel design, easy installation, low cost.

Siemens Milltronics MBS:  Use for medium power range, suitable for monitoring products such as sand, minerals, animal feed. Unique modular design should be easy to install, repair, improve equipment, low cost.

Siemens Milltronics MUS: Used for medium to large power ranges, working with products such as building materials, minerals. Unique modular design, easy to install and improve equipment, low cost.

Siemens Milltronics MCS: Used with a large capacity range, using TASS speed transformer, Same design as the above product lines, especially the load cell made of stainless steel.

Siemens Milltronics MSI and MMI: Widely applied in light and heavy industries, harsh working environment: coal, iron and steel, sand... Modular design with 2 parallel loadcells increases accuracy and load capacity. Accuracy from 0.5 – 0.25% capacity can reach 12,000t/h. MMI is a 2 or 3 MSI system, which has better accuracy.

Speed Sensor (Siemens Speed Sensor):

Fig.04 Siemens Milltronics MSI and MMI

Siemens has fully met the requirements of customers by offering sensor lines with the following features:

   ✔️ Easy to install.

   ✔️ High accuracy.

   ✔️ Standard IP65 - IP67

Integrator

The Miltronic Siemens integrator processes the loadcell and speed sensor signals transmitted continuously during the measurement, and calculates the instantaneous flow capacity as well as the cumulative capacity of the conveyor weighing system. The integrator displays the main speed values, mass, weighing capacity, loadcell values and speed sensor feed back on the LCD display. Or output signals such as: analog output current mA, alarm relay or pulse output signals of the accumulator.

Besides, it can perform basic control functions such as PID, batch control, and communicate with other control devices according to RS232, PROFIBUS, MODBUS communication standards.

BW500 is the multifunctional integrator for SIEMENS Belt Scale scales. The function processes speed values and determines the value of the load to adjust the amount on the conveyor. Load value and parameters will be displayed on the LCD screen. 

Figure.5. Miltronic Siemens BW500

  ✔️ Digital signal output and analog output.

  ✔️ Integrated two PID controllers, suitable for both conveyor control and Rotary Valve feeding applications.

  ✔️ Built-in 5 programmable relay outputs.

  ✔️ Bus communication.

  ✔️ Self-aligning point 0.

  ✔️ Capable of connecting up to 6 loadcells (Force Sensor).

For more information please contact us:

THIEN TAN ENGINEERING TECHNOLOGY CO., LTD

🏠 Headquarters: 1685/37 Le Van Luong, Hamlet 3, Nhon Duc Commune, Nha Be District, Ho Chi Minh City

🏠 Representative office address: DP12, Dragon Parc Villa, Phu Long Residential Area, Nguyen Huu Tho Street, Phuoc Kien Commune, Nha Be District, HCMC

📞 Phone: 028 3636 7192     📠 FAX: 028 3636 7092

🏘 Hotline: 0985 715 585

📧 Email: info@thientanetc.com