Among the many separation equipment in industrial production, the decanter centrifuge has become an indispensable and important equipment in the industries of sewage treatment, food processing, chemical and pharmaceutical, energy and minerals due to its continuous, efficient and highly automated characteristics. For many companies, purchasing a decanter centrifuge with excellent performance and high cost performance is a key step to improve production efficiency and reduce operating costs.
Basic knowledge before purchasing equipment
Before formally discussing the core parameters, let’s first briefly understand the basic concepts of the decanter centrifuge and its applicable scenarios
What is a decanter centrifuge?
The decanter centrifuge (Decanter Centrifuge) is a device that uses the powerful centrifugal force generated by high-speed rotation to continuously separate solid-liquid mixtures. Its main features are:
Continuous feeding, continuous separation, and continuous discharge
Wide range of application: suitable for high-concentration, high-viscosity, and high-solid materials
High degree of automation, supporting all-weather operation
Good cost control, especially in large-scale processing scenarios
Examples of application scenarios
Urban sewage treatment plants: sludge concentration and dehydration
Food industry: solid-liquid separation of pomace, bean dregs, and wine lees
Chemical industry: crystallization separation, catalyst recovery
Petroleum drilling: drilling fluid purification and recovery
Medical field: separation of bacterial fluid and Chinese medicine extraction residues
Core parameters that must be understood for the first purchase
Whether the selection is reasonable directly affects the working efficiency, operation stability and maintenance cost of the equipment. The following five parameters are the most core and most important indicators in the purchase of horizontal screw centrifuges.
1. Drum Diameter & L/D Ratio
The drum is the core structure of the horizontal screw centrifuge, and the material separation process is almost entirely completed inside it. Its size directly affects the centrifugal force, processing capacity and separation efficiency.
Diameter (D): determines the size of the centrifugal force. The larger the diameter, the higher the separation efficiency per unit time.
Length-to-diameter ratio (L/D): refers to the ratio of the drum length to the diameter, which affects the separation time and production capacity.
Practical suggestions:
The L/D ratio is generally between 2.5 and 4.5. The larger the L/D, the longer the material residence time and the more thorough the separation effect, but the equipment volume and cost will also increase.
For materials with high water content and difficult to dehydrate (such as urban sludge), it is recommended to choose a model with L/D ≥ 3.5.
2. Differential and differential speed
There is a differential speed between the speed of the screw propeller and the drum (usually a few to dozens of revolutions), which controls the propulsion speed of the solid sediment and is a key parameter that determines the slag discharge efficiency and the moisture content of the mud biscuit.
Differential speed is too fast: the slag discharge is fast but the moisture content is high, and the dehydration is not thorough
Differential speed is too slow: the dehydration effect is good but it is easy to block and the processing capacity decreases
Practical suggestions:
It is generally recommended to use equipment with variable frequency adjustment of differential speed, which can dynamically respond to feed fluctuations.
In industries such as medicine and chemical industry that require high separation accuracy, differential speed control should be more accurate and stable.
3. Material handling capacity
The processing capacity of the equipment determines the volume of material that can be processed per unit time, which is one of the data that customers are most concerned about when purchasing.
The processing capacity is affected by multiple factors:
Material type (is it easy to settle? Solid content?)
Feed concentration and viscosity
Drum size
Screw propulsion efficiency
Actual operating speed and differential speed setting
Although the structure of the decanter centrifuge is complex, as long as you master the correct selection ideas and focus on the core parameters, you can effectively avoid procurement risks and improve the user experience.
As China’s leading decanter centrifuge manufacturer, we not only provide the equipment itself, but also are willing to provide you with one-stop support services from solution design, process optimization, trial machine testing to after-sales guarantee. Welcome to contact us for exclusive industry solutions and selection recommendations!
