What is the packing, packing standard and the meaning is what?
The definition of a, packing packing refers to be populated from other objects in the material.
In engineering, packing refers to the inert solid materials in the packed tower, pall ring and raschig ring, for example, its effect is augmenting the -
Fluid interface, make its strong mixing each other.
In the product, packing, also known as filler, it is to point to to improve the processing performance and mechanical properties of the products and (
Solid materials to reduce costs.
In the field of wastewater treatment, it is mainly used for contact oxidation process, the microbes will accumulate on the surface of packing, to increase the contact with the surface of the sewage, the sewage degradation process.
Advantages: simple structure, low pressure drop, easy to use corrosion resistant non-metal materials etc.
For gas absorption, vacuum distillation and operation, dealing with the corrosive fluids are applicable.
Weakness: when the tower increases neck, causing the gas and liquid distribution, such as poor contact, resulting in decreased efficiency, called amplification effect.
Packed tower and more weight, high cost, cleaning maintenance, shortcomings and so on packing loss big trouble.
Second, filler selection criteria packing data mainly includes the geometry characteristic of the specific surface area and porosity, packing factor and so on, is basic for packing performance evaluation parameters.
1, the specific surface area per unit volume of packing filler surface area known as the specific surface area, with a said that its unit for m2 / m3.
The greater the specific surface area of the filler, provided by the gas-liquid mass transfer area.
Therefore, the specific surface area is an important index for packing performance evaluation.
2 holes in a rate per unit volume, the gap filler volume called voids, expressed in e, its unit is m3 / m3, or expressed in %.
Packing of the void fraction, the greater the gas through the ability and the greater the pressure drop.
Therefore, the void fraction is another important index for packing performance evaluation.
3, specific surface area of the packing factor and the ratio of the third power of void fraction, the a/e 3, known as the packing factor, expressed as a f, the unit is 1 / m.
It said the fluid mechanics performance of the filler, the smaller the f value, show that the smaller the resistance to flow.
Packing performance mainly depends on: is there a larger specific surface area (
M2 / m3 packing layer)
Liquid in the filler surface has better performance of uniform distribution airflow can sauce evenly distributed in the packing layer has a larger void fraction (
The m3 / m3 packing layer)
Under the condition of the same action, the bigger the specific surface area of the packing, the gas liquid distribution more uniform, the better surface wettability, the mass transfer efficiency is higher;
The void ratio, the greater the structure of packing is more open, the flux, the greater the pressure drop is also lower.
Using fuzzy mathematics method to evaluate the performance of nine kinds of commonly used filler, comprehensive performance is good, the wire mesh corrugated packing raschig ring is poor.
The choice of packing include determining the kinds of packing, specification and material, etc.
The selected packing should meet the requirements of production process, and to make the equipment investment and operation cost is low.