Mixing is indispensable to modern industrial production processes , with the continuous development of Chinese industry , hybrid systems and the development of hybrid devices will become increasingly powerful . Mixed cover the entire industrial sectors , such as chemicals, food , building materials, pharmaceuticals , fertilizers, we use products every hour every day there is at least a step in the production of hybrid technology .
I. Overview of Hybrid and Mixer
Refers to mixing by two or more physical parameters of the material together, without any chemical change.
Mixed including artesian mixing and mechanical mixing . Hybrid means the movement of materials between gravity , through its own friction reach a final uniform mixing ; mechanical mixing means to force the material through mechanical action to achieve a final uniform mixing . Generally mixed gas mixture is gravity ; dimensional mixing equipment mix for the gravity combination of mixing and mechanical mixing ; all mixed in the mixing vessel are not exercising mixed mechanically mixed .
Mixing equipment of good or bad depending on the physical assessment .
A, mixing uniformity: Analysis Material Participation bad physical quantity obtained through probability theory , mixing uniformity is determined by the type of mixing equipment .
B, dead : refers to the material in the mixing vessel can not participate in mixed physical phenomena dead evaluate the percentage of good or bad physical mixing equipment .
C, mixing time : To evaluate the physical mixing speed , start mixing refers to the mixing of different materials to achieve uniformity within the time required , the mixing time is determined by mixing equipment types and models OK.
Second, select the type of powder mixing equipment
A wide variety of powder mixing equipment , the paper mainly on mechanical mixing equipment commonly used equipment on the market at present China double helix cone mixer, horizontal mixer gravity , horizontal coulter mixer, horizontal ribbon mixer for analysis :
( A ) , the double helix cone mixer
A, mixing space is an inverted cone , barrel body has two , three or single helical axis in the case of rotation and revolution along the tank wall , the motor reducer power unit at the upper end of the mixer .
B, mixed material scope of large, mixed material density deviation diameter deviation requirements are not very strict , easy to control heat or friction material from electrostatic
C, when the mixed material role in the destruction of small crystals .
D, low power requirements when mixing equipment , the same type of equipment motor power greatly reduced.
E, device model can be extended to large, Chinese -made at a maximum of 30 cubic meters.
F, the mixing time is relatively long, but a large equipment into three helix form , can greatly reduce the mixing time .
G, the main application and mixing powder and powder , can be mixed into the material into a large amount of liquid is sprayed , the entire process of mixing is reflected in the solid powder material , application example dyestuff additives , plastic particles, etc. .
( Two ) Horizontal mixer gravity
A, the twin mixing space forms a U-shaped horizontal drum , drum body has two horizontal axes , with the blades projecting arm shaft , two mixing shafts rotating in opposite directions , the motor reducer in the side of the main equipment .
B, Main the powder particles mixed , mixture of materials suited to the light
C, mixing the materials for a wide range of movement of the material with a small range of the crystal damage.
D, equipment , all materials are mixed in a high state of motion , power demanding .
E, mixing time is the fastest mechanical mixing apparatus .
F, China -made in a maximum of 20 cubic meters.
G, the main application and the powder mixed with the powder , the material can be mixed in the form of particles , can be
In the mixing material is injected into a small amount of liquid, but the entire process of mixing embodied as a solid powder material , application example dry mortar , salt , fertilizer and other .
( Three ) Horizontal coulter mixer
A, mixed forms of horizontal space drums , barrels body has a horizontal axis with a coulter ; at the side of the barrel with a large number of high speed cutter, mixed with the main axis of 90 degrees in the main equipment motor reducer the end .
B, high speed mixing of the knife movement , the materials to a great extent the crystal damage.
C, with power requirements in a medium mixing time .
D, Chinese -made in using up to 20 cubic meters.
E, the main application and the powder mixed with the powder , the material can be mixed with a small amount of short fibers in the mixed material is injected into a small amount of liquid. Application Example building materials, cornstarch , fiber powder mixing .
( Four ) horizontal ribbon mixer
A, U-shaped drums mixing space horizontal form , the body has a whole barrel ribbon axis . Motor reducer at the end face of the main equipment .
B, mixing is relatively stable, the destructive effects of the crystal small .
C, the device all the materials are mixed in the overall state of motion , power demanding.
D, the mixing time is relatively short.
E, the main application and the powder or a powder and mixed with the viscous material , the material can be mixed to the large amount of liquid is sprayed into the mixed material in the entire process of the solid body can be reflected sticky powders can also be reflected , application Example thickening pink, gray face paint.
Third, the mixing device size selection
The size of the mixing device , the current domestic do 30 cubic meters, mainly produces for Shanghai , Zhejiang, Sichuan . On the mixing process and mixing volume requirements , mixing equipment can be divided into experimental 0.05 to 0.5 cubic meters ; production of 0.5 to 6 cubic ; batch type 4 to 30 cubic meters ;
1, the experimental equipment
Less demanding production capacity , mainly in business investment early experimental or experimental production .
2 , production equipment
Require high production capacity , mainly for corporate investment and production products, such equipment is relatively high strength design , no power required , with other production equipment, including ingredients, automatic feed, automatic discharge , the manufacturing of a complete mixed production lines, production efficiency is very high , the investment is relatively low. According to production requirements , a set of production line of one or two products , does not require long-term replacement of product forms , equipment to achieve the assembly line, instead of the large quantity needed to choose a large equipment technical requirements.
3 , batch -type equipment
Mainly used in some very demanding mixed batch of places, such as dyes , food. Same batch can not have color, taste the difference and other special request .
Fourth, mixed auxiliary function selection
Depending on the requirements of the mixing process , mixture of materials require different mixing method and mixing environment . Depending on the mixing device is designed mixed mode of ancillary mixing function , depending on the requirements of the different mixing auxiliary functions.
( A ) , heating or cooling
During the mixing of materials , heating is a common phenomenon .
1 , some material mixing process requires a certain temperature environment can be achieved, to be able to meet the material Bunsen miscibility , it is possible to improve the uniformity of mixing .
2, some mixed material itself contains a certain amount of water , the mixing process can be simply by increasing the temperature of the water drying method , a simple mixture , the drying step to complete the function .
Mechanical device for mixing the powder in the mixing container shell heating or cooling , to ensure the mixing process within the mixing vessel at a constant temperature , the heat of the primary means of the mixer , called the conventional jacket .
Depending on the temperature requirements , a common heating methods are: ① jacket joined HTF , direct heating thermal oil heating wire heating ③ ② circulating oil heating steam cycle
In order to improve energy efficiency , heating jacket shell need to do a layer of insulation to prevent heat to the air distribution. In line with the mixing process heating requirements, equipment generally also need auxiliary boiler or other energy devices. To exclude the mixing process generated by heating steam or other distribution of material , the system needs the wind system and equipped with a dust removal system.
( Two ) , vacuum or pressurized
The material in the mixing process may be oxidized in the air or other non- state of complete process , the mixing device needs to be evacuated vessel , when necessary, inert gas is needed protection.
For example, in explosive mixing process , the need for oxygen in the mixing vessel deprived of all , and then again the container filled with argon or other inert gas to prevent the mixing process should frictional heat and explode .
( Three ) , spray
To meet the powder mixing process by adding a small amount of liquid , the liquid and the powder must be increased while the mixing uniformity , the atomization state to the liquid in contact with the powder .
For example, we mixed gray surface, if the water , gray-faced together into a container and then mechanically mixed , it is difficult to mix evenly ; if the gray-faced mechanical movement to allow water to mist and gray surface contact and mix well degree and mixing time will be greatly increased.
( Four ) , Flying Equipment
If compound mixtures are difficult to disperse fibers or other materials , the mixing process requires high-speed dispersing , mixing equipment will need to design and manufacture of high-speed rotation of the knife shaft .
Fifth, the choice of auxiliary equipment
Mixing mixer is central to the process . And mixing to increase mixing speed automated processes , the mixer is also required with other auxiliary equipment , to meet the whole mixing process . Conventional mechanical mixing equipment works are gap-type operation , a single batch of mixed materials need to be ready to join the mixer → → → the material uniformly mixed
( A ) feeding equipment
In order to improve the operation of gap-type mixing time , every time ready mixed material needed to quickly add the mixer . To prepare each require a mix of materials , ingredients can be designed manually or automatic batching .
( Two ) discharge device
Mixer according to different forms of material , different processes have different ways . But no matter what form , mixed well into the silo or other materials required under step process equipment.
Mixer valve according to different operational requirements have different options :
1 , according to the outlet valve in the form of gate valves, butterfly valves, ball valves, rotary valves , gate valve , overhead valve , arc valves.
2 , according to the mode of operation of the valve with manual , electric, pneumatic control .
VI Conclusion
Powder mix is indispensable to modern industrial process, improve mixing process is to obtain excellent product quality assurance. Excellent choice , reasonable powder mixer is the product guarantee.