What is the difference between a quantitative feeding scale and a weight loss scale?

In the field of industrial bulk material automated batching, there are many automatic weighing and feeding devices, among which quantitative feeding scales and loss-in-weight scales are common. Many users do not understand the differences between the two and are often at a loss when making a choice.

Among the customers who have consulted Guonuo, some might be more suitable for loss-in-weight scales but often inquire about quantitative feeding scales. Understanding the differences between quantitative feeding scales and loss-in-weight scales can help avoid detours when making a purchase.

Similarities between Quantitative Feeding Scales and Loss-in-Weight Scales

Firstly, both quantitative feeding scales and loss-in-weight scales are automatic weighing and quantitative feeding devices commonly used in industrial bulk material batching systems. They both possess the functions of automatic weighing and quantitative control of feeding, serving as efficient automated batching devices to improve production efficiency and quality.

Secondly, both are equipped with high-precision weighing sensors to complete material weight detection, along with display control instruments to process and display data, PLCs for automatic control operations, uploading and sharing batching data, and setting parameter information.

Thirdly, both quantitative feeding scales and loss-in-weight scales are sufficiently reliable in performance and can maintain long-term stable operation and guarantee long-term feeding accuracy in their applied industrial settings.

Differences between Quantitative Feeding Scales and Loss-in-Weight Scales

(1) Working Principle

- Quantitative Feeding Scale: Weighing sensors are installed under the scale frame to detect the weight of the conveyed material in real-time. A speed sensor is installed at the tail or on the rotating machine to detect the feeding rate.

The automatic control instrument receives weight and rate signals and calculates the material weight data. It automatically compares the flow rate with the set parameters, and the PLC controls the motor speed through a frequency converter to adjust the feeding amount, achieving a constant feeding flow rate control.

- Loss-in-Weight Scale: As the name suggests, the loss-in-weight scale calculates the discharge amount based on the real-time weight reduction of the material in the measuring hopper, while utilizing a PLC to achieve quantitative feeding.

When the material in the measuring hopper reaches the lower weighing limit, the discharge screw conveyor fixes the discharge amount according to its current rotational speed while controlling the material in the silo to quickly descend into the measuring hopper. When the loading reaches the upper weighing limit, loading stops to better shorten the feeding time.

(2) Structural Composition

- Quantitative Feeding Scale: The material conveyance of a quantitative feeding scale is horizontal, with the body being a screw conveyor or belt conveyor. It is equipped with a weighing device (weighing sensor, speed sensor), electrical components (motor, reducer, frequency converter, deviation switch, electrical control cabinet, etc.), and the control instrument is integrated into the electrical control cabinet.

- Loss-in-Weight Scale: Visually, the distinctive feature of a loss-in-weight scale is its vertical hopper. Its general components include: a measuring hopper, an inlet gate, a mixer, a discharge device, weighing sensors, a weighing instrument, and an automatic control system.

(3) Application Scope

Due to the difficulty in ensuring batching accuracy within a small measuring range for quantitative feeding scales, they are more suitable for industrial batching fields with large measuring ranges, such as building materials, cement, and chemicals.

The belt quantitative feeding scale of quantitative feeding scales has relatively poor sealing performance; if a large measuring range is required, a sealed screw quantitative feeding scale can be adopted. Loss-in-weight scales have good sealing performance and no issues with dust overflow, making them suitable for batching operations of small measuring ranges with uniform particle size for powders and granular materials.

Through the above analysis, it is believed that everyone has gained a certain understanding of the similarities and differences between quantitative feeding scales and loss-in-weight scales. Both quantitative feeding scales and loss-in-weight scales are automated weighing control devices applied in production batching, each with its own advantages and characteristics. The choice between the two in actual production completely depends on the device characteristics, on-site production processes, material characteristics, production volume, etc.