Classify Packing
2013-08-26 17:50:28
All kinds of packings is according to different loading packings.Can be divided into random packing and structured packing.
1.Random packing
Random packing is consist of a certain geometrical shape and the size of the particles.Generally deposited in a random manner in the tower,called Random packing or particulate filler.Random packing according to structured characteristics,can be divided into the ring packing,saddles,saddle-shaped packing ring and spherical fillers.Now introduce some more typical random packings.
Raschig ring,Pall ring ,Cascade mini ring,Berl saddle,saddles,metal intalox saddle.spherical packing.
(1)Raschig ring was invented by F.Rasching in 1914.It is the same height as outer diameter of a round ring. Raschig ring packing poor liquid distribution, mass transfer efficiency is low,big resistance,small flux,It has been rarely used in current industry.
(2)Pall ring packing is Raschig rings improvement in the side wall of Raschig ring out two rows of rectangular apertures, the ring was cut on one side of the wall and the wall is still connected, Another side ring bending, forming inwardly extending tongue leaves, leaves all sides of the tongue relative to ride in the center of the ring. Due to pall ring wall openings, greatly improving the ring and the ring inner surface space utilization, air resistance is small, the liquid distribution. Compared with Raschig rings, Gas fluxes of Pall rings increased more than 50%, mass transfer efficiency rise 30%. Pall ring is a widely used fillers.
(3)Cascade Mini Ring is Pall Ring improvement.Compared with Pall Ring.Its height was reduced by half and added a conical flange at one end.Due to the rate of the height and outer diameter reduce, So that the outer wall of the gas around the average path filler greatly shortened, reducing the resistance of the gas through the packing layer.
(4)Berl saddle is belong to saddle packing.The shape is like as saddle. Generally made of ceramic material.It is characterized by an open surface of all, regardless of inside and outside, both sides of the uniform flow of liquid on the surface, the surface utilization is high, curved flow, flow resistance. The drawback is prone to intussusception, resulting in part of the filler surface is coincident that the mass transfer efficiency.Berl saddle strength is very poor,earsily broken,few applications in industrial productions.
(5)Saddle Ring changes the curved surface of berl saddle into rectangular faces,sides vary in size, it becomes saddle packing. Saddle packing accumulation without overlay, a more uniform distribution of liquid.Saddle packing commonly used ceramic, its performance is superior Raschig rings. At present,The occasion of most Ceramic Raschig Ring applications in domestic has been replaced with ceramic saddle packings.
(6)Metal saddle packing(foreign as Intalox) is both structural characteristics of the ring and saddle designed a new type of filler, the filler is generally made of metal material,also called Metal Ring Saddle Packing.Saddle packings concentrate on Ring Packing鈥檚 and Saddle鈥檚 advantage.Its combination property is more excellent than Pall Ring and Cascade Mini Ring.and It is used more in random packing.
(7)Spherical packing generally use plastic injection molding,it has a kind of structures.Its characteristics is a hollow ball.can allow gas and liquid from the inside through. As the sphere symmetry of the structure,packing loading density uniform,not easy to produce holes and bridges, so good performance liquid dispersion.General spherical packing only used in some certain occasions.less of engineering applications.
In addition to the several more typical bulk packing, in recent years there have been a unique new packing configurations developed,such as Conjugate Ring Packing,Heilex Ring Packing,Nutter Ring Packing etc. The characteristics of commonly used Random packing in industry can be reference in related brochure.
2.Structured Packing
Structured packing is according to a certain geometric configuration arranged, neatly piled filler. Many different types of structured packing, according to its geometric structure can be divided grill packing, corrugated packing, pulse fillers.
(1)Grill packing is consist of stripe units through certain rules.with a variety of structural forms. The first industrial application for the wood grill grille filler. There are currently more general Ritchie grill packing, mesh grill packing, honeycomb grille filler, of which the most representative Ritchie grill packing.
The specific surface area of the lower grille filler, mainly for applications requiring low pressure drop, large load, and attempts to prevent other occasions.
(2)Corrugated packing is the most variety of structured packing in current industrial applications.It is a disc-shaped packing which consists of corrugated thins.Corrugation鈥檚 and tower axis鈥檚 inclination have 30掳 and 45掳. Assembled by two adjacent corrugated plates stacked reverse.
Corrugated packing according to structure divided wire gauze corrugated packing into perforated corrugate packing.The material is metal,plastic,and ceramic etc.
Metal wire gauze corrugated packing is main performance of corrugated packing.It is made of wire gauze.its low pressure,high separation efficiency, especially for sophisticated distillation and vacuum distillation unit,It take effective measures for difficult isolate system, heat-sensitive material system of distillation.Although the costs are high,the good performance is widely in application.
Metal perforated corrugated packing is a main performance of corrugated packing. The filler is stamped on the corrugated board sheet so many f5mm holes, can play rough distribution of the liquid on the sheet, to enhance the role of lateral mixing. On the corrugated board sheet rolled into tiny grooves, the sheet can play a fine distribution of the liquid, to enhance the surface wetting properties.
Metal rolling corrugated plate packing is another representative of the plate corrugated packing. It is the metal plate packing main difference is that the sheet surface is not punched holes, but punctures, jarring manner with the rolling of the sheet is very dense pore size of 0.4 ~ 0.5mm small puncture holes. Its separation capability is similar to network corrugated packing, but the anti-blocking capability is stronger and cheaper than wire gauze corrugated packing.
Corrugated packing has the advantage of compact structure, small resistance, high mass transfer efficiency, large capacity, large specific surface area (such as several commonly used are 125,150,250,350,500,700). Corrugated packing drawback is unsuitable for processing viscosity, easy polymerization or suspension of the material, and the loading and unloading, cleaning difficulties and high cost.
(3)Pulse packing is made with a hollow prismatic necking individuals.It is a structured packing by a certain way together.Pulse packing assembly, will form a porous prismatic channel with a constriction, the longitudinal flow channel alternating contraction and expansion of the gas-liquid two-phase generated through strong turbulence. In the necking section, the highest gas velocity, turbulent violent, thus enhancing mass transfer. The expansion section, minimizing gas velocity, to achieve separation of the two phases. Flow contraction, expansion alternately repeated to achieve a "pulse" mass transfer process.
Pulse filler is characterized by large capacity, low pressure drop, is ideal for filling the vacuum distillation. Because of its excellent performance liquid distribution reduces the amplification effect, it is particularly suitable for large column diameter of the occasion.
