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Cyclone roof

Most cyclones are designed with flat roofs. Under high pressure or high vacuum conditions, however, it is sometimes necessary to fabricate a cyclone with a domed roof. Typically, such a roof is either elliptical or hemispherical— depending on such factors as the differential pressure across the roof, wall thickness, the size of the cyclone, and the relative vortex finder-to-barrel diameter. In such instances, it is recommended that a fiat false or inner roof be installed (and properly vented if necessary) so that the flow pattern is the same as that of a conventional flat-headed cyclone. [Pg.364]

Literature data comparing roof or head designs is scarce. However, a study by Heumann indicates that both separation performance and pressure loss are negatively impacted if, on otherwise identical cyclones (see Fig. 15.1.20), a flat-headed roof is replaced by a domed-roof. The performance data reported in Table 15.1.3 is based on the results of numerous tests using mixed samples of coal fly ash under virtually identical operating conditions. At least for the conditions under which the test were performed, it is clear that the domed-roof design significantly impairs separation performance, as measured by the emission rates reported. [Pg.365]

As suggested by Heumann, and on basis the writers own observations, any void or attic space above the inlet plane tends to cause incoming solids to [Pg.365]

When the gas and solids enter a helical roof cyclone, the roof forces it to assume a helical downward spiral in the barrel section of the cyclone. With [Pg.366]

One would have to exercise care in any side-by-side comparative study of the two roof designs to ensure that the only significant difference between the flat head and helical head designs is the roof itself. This would require that  [Pg.367]


Hugi and Reh (1998) operated cyclones at loadings ranging from 10 to 50kgs/kgg (13 to 64kg/m ). They report that if the roof of the cyclone is extended, no gas outlet tube is required, and that this type of cyclone is superior to a cyclone in which the roof is not extended and a gas outlet tube is used. Muschelknautz et al. (1999) agreed with this assessment, but found that even higher efficiencies were possible if the cyclone roof was raised and a vortex tube was used in the cyclone. [Pg.611]

Pressure-recovery type vortex tubes, along with pressure-recovery type diffusers set atop the roof of the cyclone, are occasionally used to convert some of the rotational energy of the exiting gas back into static pressure. Based on data presented by Muschelknautz and Bruimer (1967), a modest amount of pressure recovery (15 to 20% reduction in vortex core pressure loss) can be achieved with a simple conically shaped vortex tube, such as that shown in frame g. More efficient recovery (35 to 40% loss reduction) is possible with a well-designed internal conical insert, such as that shown in frame h. Normally, such a vortex tube is directly connected to a wide-bodied outlet diffuser or exit scroll which sits atop the cyclone roof. [Pg.356]

Vapor recovery systems floating roof tanks pressure tanks vapor balance painting tanks white Cyclones-precipitator-CO boiler cyclones-water scrubber multiple cyclones Vapor recovery vapor incineration Smokeless flares-gas recovery... [Pg.520]

Normally the vortex finder should extend down into the conical portion of the cyclone. It is thought that the vortex finder plays an important role in the maintenance of a stable spiraling fluid flow in the cyclone, and this makes it more difficult for the particles to leak through the boundary layer on the roof of the lid of the cyclone to the overflow tube.- Without a vortex finder, the efficiency may be reduced by 4-5%. However, an excessive long vortex finder may hinder the high spin velocity in the fluid flow and thus reduce the efficiency of the cyclone. [Pg.1210]

Roof discoloration, deposition on autos can occur with cyclones and less frequently with dry centrifugal. Heavy duty air filters sometimes used as final cleaners. [Pg.233]

Aerosol for chemical analysis was sampled in the air monitoring trailer through a 1.3 cm ID stainless steel pipe. The air inlet was about 1 m above the roof of the trailer, a total of 4 m above the ground. Loss of 0.1 pm diameter particles to the walls due to turbulent diffusion was calculated to be less than 1% using the method of Friedlander (11). A cyclone preseparator (12) was used to separate the coarse (D > 2 pm) aerosol from the airstream so that only the fine (D <2 pm) aerosol would be collected for analysis. The cyclone was operated at 26-30 liters per minute (1pm) and was cleaned every 8-10 weeks. [Pg.129]

Roofing plants Crushed rock or other minerals Particulates (dust) Local exhaust system, cyclone or... [Pg.35]

Roofing plants (asphalt saturators) Felt or paper saturators spray section, asphalt tank, wet looper Crushed rock or other minerals handling Asphalt vapors and particulates (liquid) Particulates (dust) Exhaust system with high inlet velocity at hoods (3658 m/s [>200 ft/min]) with either scrubbers, baghouses, or two-stage low-voltage electrostatic precipitators Local exhaust system, cyclone or multiple cyclones... [Pg.1933]

Figure 12-97 shows a traditional spray dryer layout with a cone-based chamber and roof gas disperser. The chamber has two-point discharge and rotary atomization. The powder leaving the chamber bottom as well as the fines collected by the cyclone is conveyed pneumatically to a conveying cyclone from where the product discharges. A bag filter serves as the common air pollution control system. [Pg.1417]

In the typical spray dryer shown in Fig. 24.15 the chamber is a cylinder with a short conical bottom. Liquid feed is pumped into a spray-disk atomizer set in the roof of the chamber. In this dryer the spray disk is about 300 mm (12 in.) in diameter and rotates at 5000 to 10,000 r/min. It atomizes the liquid into tiny drops, which are thrown radially into a stream of hot gas entering near the top of the chamber. Cooled gas is drawn by an exhaust fan through a horizontal discharge line set in the side of the chamber at the bottom of the cylindrical section. The gas passes through a cyclone separator where any entrained particles of solid... [Pg.801]

The constraints on pulverized coal cofiring of tire-derived fuel are more significant than with cyclone firing. The case study reported here is unique in that they utilized whole tries fed from the boiler roof. [Pg.254]

As mentioned in Chap. 1, cyclones work as a result of the centrifugal forces acting on the particles suspended in the swirling gas stream. This causes the particles, which are denser than the gas, to move outward to the cyclone wall, along which they are transported downward to the dust exit. The cleaned gas leaves near the centerline, in a reverse-flow cyclone through the roof. In a once-through or flow-through cyclone, the cleaned gas exits out the bottom. ... [Pg.45]


See other pages where Cyclone roof is mentioned: [Pg.782]    [Pg.783]    [Pg.604]    [Pg.48]    [Pg.275]    [Pg.289]    [Pg.354]    [Pg.354]    [Pg.357]    [Pg.364]    [Pg.439]    [Pg.782]    [Pg.783]    [Pg.604]    [Pg.48]    [Pg.275]    [Pg.289]    [Pg.354]    [Pg.354]    [Pg.357]    [Pg.364]    [Pg.439]    [Pg.554]    [Pg.782]    [Pg.265]    [Pg.2399]    [Pg.1297]    [Pg.1788]    [Pg.105]    [Pg.102]    [Pg.1782]    [Pg.649]    [Pg.175]    [Pg.2]    [Pg.13]    [Pg.13]    [Pg.19]    [Pg.20]    [Pg.20]   
See also in sourсe #XX -- [ Pg.782 ]

See also in sourсe #XX -- [ Pg.364 , Pg.365 , Pg.366 ]




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