Sparger

Coarse bubble systems are typically found with orifice, perforated disks, or pipe spargers. Under most reaUstic conditions, bubbles of about 4—6 mm are formed. Eor a wide range of sizes... 

Fig. 3. Commercial aerating systems. Diffused aerators utilizing (a), (b) pipes, (c) a sparger, and (d) underwater air-supply tubes (e) a mechanical aerator (f)...

Fig. 17. Pilot-plant ammoniator—granulator, (a) Side view, showiag placement of acid and ammonia spargers, and (b) feed end view (71,72).

Fig. 19. TVA-type ammoniator—granulator incorporating a pipe cross reactor. 1, ammonia sparger, located at the 4 o clock position 11.4 cm from granulation shell with holes facing the rotating stream 2, phosphoric acid sparger, located to discharge phosphoric acid onto the top and near the center of the rotating bed of materials 3, pipe cross reactor 4, scmbber Hquor distributor, located above the bed in granulator to dribble scmbber Hquor onto bed.

Fig. 13. Examples of pipe gas distributors (a) simple sparger, (b) details of the pipe, (c) wagon wheel, and (d) multilevel distributor.

Many initiators attack steels of the AISI 4300 series and the barrels of the intensifiers, which are usually of compound constmction to resist fatigue, have an inner liner of AISI 410 or austenitic stainless steel. The associated small bore pipework and fittings used to transfer the initiator to the sparger are usually made of cold worked austenitic stainless steel. The required pumping capacity varies considerably from one process to another, but an initiator flow rate 0.5 L / min is more than sufficient to supply a single injection point in a reactor nominally rated for 40 t/d of polyethylene. 

For small instaUafions, column foam separators are more suitable. Waste flows downward in the column whereas gas spargers, located at the bottom, give countercurrent flow. The foam generated is carried upward to a foam breaker and coUector. 

Steam is introduced at the base of the whiskey column through a sparger. Where economy is an important factor, as in a fuel alcohol plant, a calandtia is employed as the source of indirect heat. The diameter of the stiU, number of perforated and bubble cap plates, capacity of the doubler, and proof of distiUation are the critical factors that largely determine the characteristics of a whiskey. 

The KEN-FLOTE column (11) is one of several column flotation processes based on a countercurrent principle. The feed slurry containing reagents is iatroduced iato the column just below the froth zone. Air is iujected at the bottom of the column via an air sparger. Wash water is sprayed within the froth zone to reject the entrained impurities from the froth. Test results on this column iadicate that a 6% ash product coal having a combustible-recovery of 75—80% can be obtained. A 70—80% pyrite reduction is also claimed. Figure 2 shows the operation of such a column. 

Pneumatic Methods. Gas iatroductioa is coatroUed by iajectioa through capillary tubes, siatered-glass spargers, diffuser stoaes, and the like. 

Bubbles in a liquid originate from one of three general sources (1) They may be formed by desupersaturation of a solution of the gas or by the decomposition of a component in the liqiiid (2) They may be introduced directly into the liquid by a bubbler or sparger or by mechanical entrainment and (3) They may result from the disintegration of larger bubbles already in the liquid. 

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