With powder enriched product variety , as one of its main production equipment mixer type is also more diverse . Originally, it was the manufacturer of the powder product is a good sign , because different devices to meet different production needs , and even some new hybrid devices and institutions to solve many of the original equipment is difficult to solve common problems . But most of the equipment user and can not keep abreast of new equipment and new institutional advantages , either go with the flow in the selection of areas buy conventional equipment , either empirically buy the same type of equipment used , and even some of the procurement officer may only recognize the brand , that the price high product will certainly apply. In fact, talent and technology flows have been very ordinary, the introduction of foreign technology also often , but on the mechanical structure, mixing equipment alone is a kind of complex mechanical device, so the device manufacturer 's economic strength does not fully represent their technical strength, but depends on the corporate design personnel structure principle and performance characteristics of the device have sufficient understanding , in particular, whether the requirements for different production flexibility to design a suitable production equipment and key structure .
Reasonable choice of production equipment and structural configuration , not only can fully meet the requirements of production , but also can effectively reduce energy consumption, save time, reduce equipment maintenance costs , to obtain good performance and low cost . Here equipment selection should pay attention to some common sense , a brief analysis and presentation :
One , according to the precision required to select mixing equipment . Accuracy of the mixing apparatus is to ensure the quality of the basic elements of the powder product , its content generally comprises mixing uniformity, natural residues , and the sealing properties. Like food, feed premix and add some chemical materials in this regard generally have relatively high requirements. To feed premix for example, the production equipment according to national standard must be met, mixing uniformity coefficient of variation cv ≤ 5%, natural residue ≤ 0.8%, no significant blowdown phenomenon , and some higher standard , and its choice of commonly used equipment has axis paddle mixer, conical twin- screw mixer , containers and mixing equipment while rotating the rotor , some high profiled grinding and mixing equipment such as air flow stirred under certain conditions, can meet these requirements. In addition, some mixing device in normal circumstances can not reach a target , but often after use some special structure will be effectively improved . If the uniaxial efficient mixer using three-dimensional structure of the rotor blade will after mixing coefficient of variation CV from 8% to 5% , or even less than 3% ; Another example is the use of most of the horizontal-type mixing apparatus at 90 ° all very large opening and blowing self-cleaning system can greatly reduce the amount of material remaining natural , in the use of oblique wedge -type discharge door shaft gas seal structure and the structure can basically put an end to the mixer after the leakage of material phenomena .
Second, according to working conditions select mixing equipment . Working conditions more extensive content , including the physical properties of materials and chemical characteristics and impact of the equipment , the material in the mixing process without special handling requirements and the installation of equipment and space, which is more limited extent due to various conditions are different, it is difficult to have a clear standard , where only getting off on the general conditions for the selection and mixing equipment to make an important impact on the structure of shallow slightly analysis:
l, the proportion of different materials , mixing equipment in addition to structural strength and power of different things, its discharge door , the rotor , the body structure of the form even speed and other performance parameters also tend to have a greater difference , can not be seen simply as part of its strengthening or power scaling. Such as a ribbon blender hops commonly used double -headed wide ribbon , and mixed iron Pink is commonly used single interleaved spiral ribbon and mesh the two remaining structures also have a very clear distinction , speed also a great difference .
2, for fine-grained materials , paying particular attention to the tightness of production equipment , while its residues should be carefully considered. For example twin-shaft paddle mixer flour , it is best to use 90 ° full- grown simultaneously open the door, blowing self-cleaning system , inclined wedge -type gas discharge doors and shaft sealing structure in order to better ensure the seal and reduce residues, while the best use of catchy bag to replace the return duct exhaust to avoid fine flour mixed with return air from excessive spray nozzle .
3 , multi-faceted consider other special properties of the selection of the device. As illiquid or add more liquid materials , according to the specific circumstances of the role of rational use of strong shear mixing coulter , knife , broken rollers and other institutions ; wear faster processing or institutions should be designed to wear you can adjust and change ; due to the material bonding and need frequent cleaning equipment should be set such as self-cleaning device and a scraper convenient cleaning doors ; shape or particle state does not allow destruction of the material , the appropriateness of using a container such as a rotary mixer . Mainly rely on convective mixing and diffusion mixing and mixing process is relatively soft equipment.
4 , along with the need for heating or chemical reactions mixed materials , in addition to selecting the appropriate production materials and temperature control structures , but also pay attention to the temperature changes on the device itself, the impact of institutions . If the best selection of small discharge door open structure , if you must use a large door structure , be sure to use oblique wedge -type discharge door and so have the ability to automatically compensate for the material structure, so as to avoid thermal deformation of the material parts and reduce seal reliability ; while equipment such as spindle and rotor mechanism design should also take the necessary measures to compensate for linear expansion .
5 , select mixing equipment installation space is often needed to consider. Such as horizontal mixer are generally applicable to large area and height restrictions of the occasion, vertical mixer , by contrast, continuous mixers for space for small occasions , while v- drum mixer and the mixer with the same size of the other mixed equipment, compared space generally much larger, but it also has easy to move , convenient layout advantages. Of course , in addition to the installation of the device itself outside dimensions , reasonable layout and installation site can also be effective in improving equipment mounting space conditions .
Third, according to the economic situation selecting mixing equipment . Economic costs are often preferred when the user selects the device one of the factors taken into account , which requires mixing equipment procurement staff on various performance parameters and have a comprehensive understanding of the market price .
To obtain good performance and low cost equipment , personnel need to purchase the accuracy specifications of the equipment , all kinds of working conditions and the company has a comprehensive understanding of the economic situation , and then a comprehensive comparison of the actual situation , the scientific selection . In addition, the proposed mixing process and mixing of the material effects of the specific requirements, by experienced manufacturers to provide the relevant basis for selection and selection may well be a viable approach.