Definition
An emulsifying homogenizer is a device that mixes and disperses two or more immiscible liquids (usually oil and water) through mechanical action to form a stable and uniform milky liquid. Its core function is to break the dispersed phase material into tiny particles and distribute them evenly in the continuous phase, so as to obtain an emulsion system with narrow particle size distribution and high stability.
How it works:
The working principle of the emulsifying homogenizer is mainly based on high-speed shear, collision and hole effect. The equipment usually consists of a rotor rotating at high speed with a precisely matched stator. When working, the rotor rotates at high speed in the stator cavity, generating a powerful centrifugal force. The material is sucked into the rotor area from the bottom or center of the equipment and is subjected to strong mechanical shear in the narrow gap between the rotor and the stator. At the same time, the high-speed flowing liquid generates a local pressure difference, triggering a hole effect and producing instantaneous high pressure and microjets. The synergy of these forces causes the droplets to be repeatedly torn, broken, and dispersed, ultimately achieving a homogeneous emulsification effect. Its ability to break droplets can be described qualitatively by the following relational expressions:
E ∝ (ρ * N³ * D⁵) / d
Among them, E represents the emulsification energy, ρ is the material density, N is the rotor speed, D is the rotor diameter, and d is the stator gap. This equation shows that higher rotational speeds with smaller clearances generally contribute to smaller droplet sizes.
Main measurement and evaluation methods
The evaluation of the treatment effect of the emulsion homogenizer mainly revolves around the particle size distribution and stability of the emulsion. Laser diffraction is often used to characterize the dispersion uniformity by measuring the scattering mode of laser by the particle group, and calculating the average particle size of the volume (D[4,3]), the average particle size of the surface area (D[3,2]) and the span. Emulsion stability can be accelerated by multiple light scattering techniques to predict the storage stability of the sample by monitoring changes in transmitted and backscattered light under gravity or centrifugal forces. In addition, viscosity measurement and microscopic morphological observation (such as optical microscopy) are also common means to assist in evaluation.
Performance Factors
The final effect of the emulsifying homogenizer is affected by multiple factors. In terms of equipment parameters, the linear speed of the rotor and the geometric design of the stator rotor structure (such as tooth shape, clearance, and number of stages) directly determine the shear strength and frequency of action. Process parameters include processing time, treatment temperature, and mode selection for cycling or single pass. Material properties are also critical, including the ratio of the two phases, viscosity, surface tension, and the type and amount of emulsifier. These factors are interrelated, such as high-viscosity materials that may require stronger shear forces or longer processing times, and suitable emulsifiers that reduce interfacial tension and assist in mechanical action to obtain more stable microemulsions.
Applications:
Emulsification homogenization technology is widely used in many industrial and scientific research fields. In food processing, it is used in the production of sauces, dairy products, beverages, etc., to improve taste and shelf life. In the cosmetics and personal care industry, it is used to manufacture creams, lotions, shampoos, etc., ensuring that the product has a delicate and stable texture. In the chemical industry, it is used to prepare pesticide emulsions, coatings, inks and nanomaterial dispersions. In the field of biotechnology, it can be used for cell disruption or liposome preparation. The common goal is to create a stable and uniform multiphase hybrid system.
Equipment selection considerations
Selecting the right emulsifier homogenizer requires a comprehensive evaluation of specific needs. First, it is necessary to clarify the characteristics of the material being treated, such as initial viscosity, solid content, sensitivity to temperature, and target particle size. Choose the right size of equipment based on processing volume (lab size, pilot or production). Pay attention to the core parameters of the equipment, such as maximum operating speed, motor power, stator rotor material (corrosion and wear resistance are considered), and the type of replaceable dispersion head. In addition, whether the equipment has additional functions such as vacuum defoaming, in-line cleaning, and temperature control is also a consideration to improve the process level and efficiency. It is recommended to verify the processing capacity of the equipment for specific materials through small test experiments before making a decision.