Sparger pipe

The nozzle or shroud details inside a sparger pipe grid are illustrated in Fig. 7. 

Sparger piping to be supported to control vibration and the suddenly applied load from the relief discharge. 

When tank mixes were evaluated, the BALAN Dry Flowable was first dispersed in the spray water (328 ppm hardness with iron) and then the other product was added. Table V describes the details of testing at a rate of 2.5 Ib/acre at 20 gal/acre with sparger-pipe agitation. After four repetitive evaluations in which the contents were sprayed out and in which there was no clean out between tankfuls, the screens were clear and there was no residue in the bottom of the tank. The system was not cleaned out between runs to better simulate continuous spraying in actual use. Table V also describes the same type of evaluation with a jet agitator rather than a sparger pipe. This resulted in little residue in the in-line screens and none on the bottom of the tank. 

The product was also tested with both sparger pipe and jet agitation at a rate of 5 gal/acre (Table VI). These conditions resulted in some residue but the herbicide did spray satisfactorily. Obviously, more vigorous agitation would more fully suspend the product and would result in less residue. 

Fig. 4.42 Dependence of the sorption number 10 Zacc. (4.111) upon normal gas throughput qn g for different spargers (pipe and dome aerators) and for Kenics aerator ( ) from [629] 8...

Sparger pipes are discussed in detail in Sec. 4.2. That discussion also applies to a sparger pipe introducing an intermediate feed. 

If a high feed pressure drop is acceptable, the use of a sparger pipe (Fig. 4.36) is recommended (289) when the vapor inlet F-factor ranges between 52.4 VAP and 81.2 VAP. The use of a sparger pipe eliminates the need for a more sophisticated vapor-distributing device. 

A vapor distributor with insufficient pressure drop may be ineffective. A case has been reported (75) where poor column efficiency resulted from specifying a vapor distributor with lower pressure drop than recommended by the manufacturer. The vapor distributor (or vapor-distributing support) pressure drop can be minimized by entering the feed via a sparger pipe with the bottom quadrant removed (rather than perforated). Although such a sparger pipe will not be an effective vapor distributor, it will serve to break the incoming vapor jet and reduce its velocity head. 

When a sparger pipe enters an intermediate feed, vapor jets must not impinge on redistributor liquid surface or other packed-column internals. Liquid surface agitation in redistributors, or mechanical damage to internals, can cause maldistribution, which can be detrimental to column efficiency. 

Where pressure drop is critical, a sparger pipe with the bottom quadrant cut out (rather than perforated) is sometimes used, but at the penalty of inferior vapor distribution. Similarly, the sparger can be entirely eliminated and substituted by a dog house baffle parallel to the direction of fluid entry. This baffle is somewhat wider than the nozzle diameter and stretches from wall to wall parallel to the direction of the incoming fluid. The author is familiar with one experience where addition of a "dog house baffle eliminated a packed-tower vapor maldistribution problem. 

The superficial velocity of the dissolving fluid at the bottom of an upflow dissolver is typically about 2.5 mhr i (say, 2-4). The depth of the salt bed usually is kept above 1.5 m. The feed brine or water enters a sparger-pipe arrangement through one or more peripheral connections. Proper design of the sparger is necessary for good flow distribution. 

Summary. For an orifice diameter of 0.025 m, the downwardly directed concentric-ring sparger has 2,401 nozzles placed on four concentric rings. The pitch is 0.04 m. Sometimes the holes are staggered on the sparger pipe. Also it is a common practice to place two nozzles at a given cross section as shown in Fig. 8. 

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