What are the common problems and precautions when using a vacuum emulsifier?

What are the common problems and precautions when using a vacuum emulsifier?

   

Vacuum emulsification refers to the rapid and uniform distribution of one or more phases into another continuous phase using a high-shear emulsifier in a vacuum state, using the strong kinetic energy of the machine to make the material narrow in the stator and rotor. In the gap, it takes hundreds of thousands of hydraulic shears per minute. Centrifugal extrusion impact tearing and other comprehensive effects, instantaneously and evenly dispersed emulsification, after high-frequency cycle reciprocating, finally get bubble-free fine and stable high-quality products.

Vacuum emulsifier specialized machinery has an advantage in competition, and no vacuum technology is not realistic. Science and technology are productivity, and people are increasingly enjoying the enormous benefits of science and technology. The advent of vacuum emulsifiers has made people understand that the huge potential of science and technology can still be explored. The introduction of advanced technology has led to a rise in sales of vacuum emulsifiers, which has been welcomed.

I believe that when using different devices, I can encounter some different problems, which is annoying. Today, Xiaobian will summarize some of the experiences that I have had when I use this device. Let's take a look.

The temperature of the equipment has a great influence on the emulsification, but there is no strict limit on the temperature. If the oil and water are all liquid, the emulsification can be achieved by stirring at room temperature. Generally, the emulsification temperature depends on the melting point of the high melting point substance contained in the two phases, and factors such as the type of the emulsifier and the solubility of the oil phase and the aqueous phase are also considered. In addition, the temperature of the two phases should be kept nearly the same, especially when emulsification is carried out on waxes and fat oil phase components containing a higher melting point (above 70 ° C), the low-temperature aqueous phase cannot be added to prevent waxing, Lipid crystals precipitate, resulting in a massive or coarse uneven emulsion. Generally, in emulsification, the temperature of both the oil and water can be controlled between 75 ° C and 85 ° C. If the oil phase has a high melting point wax, the emulsification temperature is higher. In addition, if the viscosity increases greatly during the emulsification process, so-called too thick and affects the agitation, some emulsification temperatures can be appropriately increased. If the emulsifier used has a certain phase inversion temperature, the emulsification temperature is also selected around the phase inversion temperature. The emulsification temperature sometimes affects the size of the emulsion particles. For example, when the emulsification temperature is controlled at 80 ° C, the emulsion particle size is about 1.8-2.0 μm, and the particle size is about 6 μm. When emulsified with a nonionic emulsifier, the emulsification temperature has a weak influence on the particle size.

The factors affecting the emulsification results of the equipment are as follows

1. The form of emulsification head of vacuum emulsifier (batch type and continuous type) (continuous type is better than batch)

2, the shear rate of the emulsified head (the bigger, the better the effect)

3, the tooth structure of the emulsification head (divided into the first tooth, the middle tooth, the fine tooth, the superfine tooth, the better the fine tooth effect)

4, the residence time of the material in the dispersion wall, emulsification, and dispersion time (can be regarded as the same motor, the smaller the flow, the better the effect)

5, the number of equipment cycles (the more, the better the effect, the time limit to the equipment, it can not be better)

How can the equipment pump not produce a vacuum?

The main structure of the current vacuum emulsifier is the stator and rotor system, and its structural form has also been updated, from the blade structure to the current claw structure, from single-piece shearing to multi-layer dual bite shearing, from single-piece suction to Two-way suction, which distributes one or more phases quickly and evenly into another continuous phase; in the normal case, the phases are mutually incompatible, due to the high tangential speed and high speed of the rotor rotating at high speed. The strong kinetic energy brought about by the frequency mechanical effect makes the material in the narrow gap of the stator and the rotor subject to strong mechanical and hydraulic shearing, centrifugal extrusion, liquid layer friction, impact tearing, and turbulence. The dissolved solid phase, liquid phase, and gas phase are uniformly and finely dispersed and emulsified under the action of the corresponding mature process and the appropriate amount of additives, and after high-frequency circulation and reciprocation, a relatively stable high-quality product is finally obtained.

Therefore, almost all processes (including food, dairy, chemical, petroleum, asphalt, etc.) are inseparable from the mixing, emulsification, pulverization, dispersion, dissolution, and other processes of such heterogeneous raw materials. Traditional mixing or shear emulsification In terms of efficiency and effectiveness, the technology lacks the key technology of grinding, which has the following obvious shortcomings:

1. Vacuum emulsifier usually has a high viscosity after mixing with liquid phase, liquid phase, and solid phase. To ensure the normal operation of the rotating stator, the relative clearance cannot be lower than 50um, so the material fineness after shear emulsification cannot be guaranteed.

2. Due to the limitation of the rotating structure of the ordinary high shear emulsifier, not only the fineness of the emulsion is not guaranteed, but also the emulsion formed after shearing is easy to break the emulsion, and it is impossible to form a relatively stable emulsion molecular structure, which is easy to precipitate and easily segregate. Now there is a new type of high-shear rubber (cone) body grinding which is a new high-tech product combining a high-shear dispersing emulsifier and rubber (cone) body grinding. It achieves high production capacity and advanced performance. The multi-functional equipment of crushing, grinding, dispersing, emulsifying, homogenizing, and conveying has fundamentally solved the technical problems that ordinary high-shear emulsifiers can not solve, and is the current advanced equipment of the world*.

3. Vacuum emulsifying machine Due to the limitation of domestic processing technology, concentricity or coaxially is difficult to guarantee, and the rotation and stator operation easily get stuck and cannot operate normally.

Equipment common faults and troubleshooting methods

First, the vacuum emulsifier common fault: the vacuum can not be established

The cause of the failure: 

(1) the valve is not closed, and the vacuum valve of the lid is not opened;

 (2) the seal is damaged and causes leakage; 

(3) the vacuum pump is not operating normally;

Remedy: 

1 close each valve; 

2 replace the seal; 

3 Check the vacuum pump, please refer to the liquid vacuum pump manual;

Second, the vacuum emulsifier common fault: the pump can not produce vacuum

The cause of the failure: 

(1) no working fluid; 

(2) serious system leakage; 

(3) wrong direction of rotation.

Remedy: 

1 check the working fluid; 

2 repair the leak; 

3 replace the two wires to change the direction of rotation.

Third, vacuum emulsifier common faults: homogenization, stirring motor does not start, or motor overload

The cause of the fault: 

(1) power line break; 

(2) motor bearing fault; 

(3) homogeneous rotor sintering; 

(4) foreign matter stuck to the homogenizer or stirrer; 

(5) winding short circuit

Remedy: 

1 Check wiring; 

2 Replace motor bearing; 

3 Check whether the homogenizing rotor is flexible; 

4 Remove foreign matter; 

5 Check motor winding (coil)