Nozzle spray

The spray nozzles in a liquid curtain must perform two functions. First, they must meter the flow to be sure the liquid reaches all sections of the curtain. Second, at each location they must break up the liquid into droplets. 

To ensure that a nozzle meets the above objectives, one must specify the following  

Each of these nozzle parameters will be discussed in the following sections. 

The capacity of a nozzle depends on the pressure difference across the nozzle s orifice. This pressure difference is usually a function of the liquid pressure at the nozzle inlet and the atmosphere. However, if the nozzle is to discharge into a volume that is greater than atmospheric pressure, this must be taken into account and the pressure difference adjusted accordingly. 

The nozzle capacity data presented in most vendor catalogs are based on the flow of water through the nozzles. The properties of fluids other than water can affect nozzle performance. For instance the flow rate of liquids denser than water will be lower in some spray systems, unless additional energy is supplied to the system to move the denser fluid, that is, a higher horsepower pump. 

These are important for irrigating the entire cross section of absorbers for proper gas-liquid contact in a pollution control units. 

These are important internal fittings for cooling towers, absoibers, pollution control 

Serial number Type Typical application Spray angle (°) Remarks 

1 Full jet Cooling, quenching, dust suppression 30-130 Full spray pattern 

2 Line jet De-greasing, spray coating, coal washing 20-120 Flat jet spray 

3 Circle jet Air/gas washing, dust control 60-130 Hollow cone spray with most of the liquid at outer edge of the cone 

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MP-suspension by automated ASTM-bulb Magnetization current by Hall-Sensor Magnetization time UV-Light intensity All Liquids (fluorescence, contamination) Process times and temperatures Function of spraying nozzles, Level of tanks Flow rates (e.g. washing, water recycling) UV-Light intensity... 

Water pressure at spraying nozzles and flow-rates. 

The system has recently been used with success for inspection of 11 inclined nozzle welds during the R1 SPRINT project at Vattenfall Ringhals, Sweden during the summer 1997. At the moment a full system and personal qualification is prepared for inspection of the pressurizer spray nozzle weld at Vattenfall Ringhals, block 2 at May, 1998. 

Direct water spray cooling must be carried out with care. The spray chamber must be designed to ensure complete evaporation of all Hquid droplets before the gas enters the baghouse. Spray impinging on the chamber walls can result ia a dust mud iaside the chamber and any increase ia gas dewpoint may result in baghouse problems or atmospheric plume condensation. Spray nozzle wear can result in coarse or distorted spray and wetted bags, and water pressure failure can cause high temperature bag deterioration. 

Fig. 6. Intake manifold system with a water-atomizing spray nozzle distributing to four individual cylinders. See text.

Leaks can be detected at once by ammonia odor unless there is already an appreciable amount of ammonia in the ak. Leaks can be exactiy located by using either moist phenolphthalein paper or an open bottie of hydrochloric acid. If a serious ammonia leak is discovered, a large column of water apphed through a fire hose having a spray nozzle can be used to absorb the vaporized ammonia. 

In any procedure involving the handling of molten sulfur, the lines and spray nozzles must be steam-jacketed, and steam pressure must hold the molten sulfur within the range of 135—155°C, where its viscosity is at a minimum. Above 160°C, the viscosity rises sharply, and at 190°C its viscosity is 13,000 times that at 150°C. 

Materials made of siHcon nitride, siHcon oxynitride, or sialon-bonded siHcon carbide have high thermal shock and corrosion resistance and may be used for pump parts, acid spray nozzles, and in aluminum reduction ceUs (156—159). A very porous siHcon carbide foam has been considered for surface combustion burner plates and filter media. It can also be used as a substrate carrying materials such as boron nitride as planar diffusion source for semiconductor doping appHcations. 

Feedstocks. Feedstocks are viscous aromatic hydrocarbons consisting of branched polynuclear aromatics with smaller quantities of paraffins and unsaturates. Preferred feedstocks are high in aromaticity, free of coke and other gritty materials, and contain low concentrations of asphaltenes, sulfur, and alkah metals. Other limitations are the quantities available on a long-term basis, uniformity, ease of transportation, and cost. The abiUty to handle such oils in tanks, pumps, transfer lines, and spray nozzles are also primary requirements. 

Drum Dyers. Indirect-heat dmm dryers, like spray dryers, are usable only for materials that are fluid initially and pumpable. Drying is effected by applying a thin film of material onto the outer surface of a rotating heated dmm using appHcator roUs, spray nozzles, or by dipping the dmm into a reservoir. Usually the dmm is cast iron or steel and chrome-plated to provide a smooth surface for ease of product release by doctoring. Dmm rotational speed is such that... 

Hydraulic jetting with water forced through spray nozzles at high pressure for cleaning tube interiors and exteriors of removal bundles is reported by Canaday ( Hydrauhc Jetting Tools for Cleaning Heat Exchangers, ASME Pap. 5S-A-2I7, unpublished). 

Evaporative condensers are used quite extensively. In most cases commercial evaporative condensers are not totally suitable for chemical plants due to the hostile atmosphere which usually abounds in vapor and dusts which can cause either chemical (corrosion) or mechanical problems (phigging of spray nozzles). 

Water flow, gal/min Spray-nozzle pressure, Ih/im Water flow per nozzle, gal/min Effective area, length X width, fd Effective height, ft Wind velocity, ft/min... 

Since leaving-water temperature checks assumption, spray pondis capable of cooling 46,000 gaFmin from 102 to 92°F with 78°F wet-bulb temperature and 5-mi/h wind. Total of 1080 spray nozzles required at 42.5 gaFmin each, nozzles at 7-lb im pressure. 

Another type of distributor, not shown in Fig. 14-64, is the spray nozzle. It is usually not recommended for hquid distribution for two reasons. First, except for small columns, it is difficult to obtain a uniform spray pattern for the packing. The fuU-cone nozzle type is usually used, with the need for a bank of nozzles in larger columns. When there is more than one nozzle, the problem of overlap or underlap arises. A second reason for not using spray nozzles is their tendency toward entrainment by the gas, especially the smaller droplets in the spray size distribution. However, some mass transfer in the spray can be expected. 

End Effects Analysis of the mass-transfer efficiency of a packed cohimn should take into account that transfer which takes place outside the bed, i.e., at the ends of the packed sections. Inlet gas may veiy weU contact exit liquid below the bottom support plate, and exit gas can contact liquid from some types of distributors (e.g., spray nozzles). The bottom of the cohimn is the more hkely place for transfer, and SU-vey and KeUer [Chem. Eng. Prog., 62(1), 68 (1966)] found that the... 

Introduction There are two types of gas-hqiiid contactors where the liquid is deliberately dispersed. In the most common, a spray nozzle is used to generate droplets. A second t me is the pipehne contactor, where the entrainment generated by flowing gas generates the droplets. 

Because of the minimal internals for solids to grow on, both types of contactors are common in foiihng services. The spray nozzle based devices are also inherently low pressure drop. 

Breakup of a. meet of liquid (Ih/elocity) . This governs drop size in most hydraulic spray nozzles. 

FIG. 14-87 Charactersitic spray nozzles, a) Whirl-chamber hollow cone, (h ) Solid cone, (c) Oval-orifice fan. (d) Deflector jet. (e) Impinging jet. (/) Bypass, (g) Poppet, (h) Two-flnid. ( ) Vaned rotating wheel. 

Two-Fluid (Pneumatic) Atomizers This general category includes such diverse apphcations as venturi atomizers and reac tor-effluent quench systems in addition to two-fluid spray nozzles. Depending on the manner in which the two fluids meet, several of the breakup mechanisms may be apphcable, but the final one is high-level turbulent rupture. 

In drying solutions or slurries of solutions, the location of the feed-injection nozzle (spray nozzle) has a great effecl on the size of particle formed in the bed. Also of importance are the operating temperature, relative humidity of the off gas, and gas velocity. Particle growth can occur as agglomeration or as an onion sldnuing. ... 

The power input from a liquid stream injected with a hydraulic spray nozzle may usually be taken as approximately equal to the product of the nozzle feed pressure pf and the volumetric hquid rate. The liquid-phase contacting power Pe may then be calculated from the following formulas ... 

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