Rotary spray system

Varga CM. Snyder HE. High-magnification shadowgraphy characterization of rotary atomizer dn lci production for pharmaceutical aj lications. Institute for liquid atomization and spraying systems conference. Toronto, Ontario. Canada 2006. 

In a semidry scrnbbing system, the solntion or slurry is dispersed by nozzles or rotary atomization systems into a fine cloud of droplets.These droplets are brought into contact with a hot gas stream (and herein lies a disadvantage to semidry scrubbing systems) that proceeds to evaporate the water in the droplets. As the water evaporates, the acids in the gas stream react with the alkali material in the drying droplets and neutralize them, forming a fine powder. Most of this powder is removed from the bottom of the spray dryer, while the remainder is entrained in the gas stream and carried out to either a fabric filter or an electrostatic precipitator (ESP). 

Kalmbach T., Hauber, M., Liebing, M., Piesche, M. (2014). Rotary atomizers— Influence of centrifugal forces and a gas flow on 3D movement of a liquid jat and its break-up. hi 26th Annual Cotference on Liquid Atomization and Spray Systems ILASS, Bremen, Germany, 8-10 September 2014. 

Mescher, A., Walzel, P. (2010). Breakup of stretched liquid threads at low gas relative velocities—Comparison of the laminar rotary atomization to the gravity condition. In 23th Annual Conference on Liquid Atomization and Spray Systems ILASS, Brno, Czech Republic, 6-8 September 2010. 

The common types of dryers are rotary, hearth, flash (spray), and fluidized beds (10). Hot gases are used invariably to remove moisture. The gas flow can be either cocurrent or countercurrent to the flow of soHds, the former tends to be more efficient. In the hearths, the gas flow is countercurrent as the soHds are raked down from one hearth to the next below. Flash dryers are very rapid because the soHds are exposed only briefly to the hot gases. Fluidized-bed dryers, which use hot gases to suspend the soHds, are rapid and efficient, but require elaborate dust coHection systems. These are preferred when fine soHds are involved, and are used commonly for drying fine coal. Indirect-fired dryers are used when the soHds are heat sensitive or combustible. 

Spray Drying and Agglomeration. Most instant coffee products are spray-dried. Stainless steel towers with a concurrent flow of hot ak and atomized extract droplets are utilized for this purpose. Atomization, through pressure nozzles, is controUed based on selection of the nozzles, properties of the extract, pressures used, bulk density, and capacity requkements. Low inlet ak temperatures (200—280°C) are preferred for best flavor quaHty. The spray towers must be provided with adequate dust coUection systems such as cyclones or bag filters. The dried particles are coUected from the conical bottom of the spray drier through a rotary valve and conveyed to bulk storage bins or packaging lines. Processors may screen the dry product to... 

While the rotary dryer shown is commonly used for grains and minerals, this system has been successfully applied to fluid-bed diying of plastic pellets, air-hft diying of wood fibers, and spray drying of milk solids. The air may be steam-heated as shown or heated By direct combustion of fuel, provided that a representative measurement of inlet air temperature can be made. If it cannot, then evaporative load can be inferred from a measurement of fuel flow, replacing AT in the set point calculation. 

Figure 30-2 illustrates a wet SO2 desulfurization system using a spray tower absorber. Figure 30-3 illustrates a rotary atomizer injecting an alk ine slurry into a spray dryer for SO2 control. 

U liters (a round bottomed flask) and 185 liters (a 6.5 ft stainless steel rotary digester). Temperatures within the vessels were regulated by partial immersion in controlled (to 100°C) water baths. Aqueous nitric acid was introduced as either a fine stream or spray into the vessels both nitric oxide and oxygen flow rate and pressure drop were independently monitored into the systems. 

Spray coating is used before and after a product is assembled particularly if already assembled and has complex shaped and curved surfaces. Many different types of spray equipment are in use to handle the different forms of paints used. They are classified by their method of atomization (airless, air, rotary, electrostatic, etc.) and by their deposition assist (electrostatic or nonelectrostatic, flame spray, etc.). Spraying techniques may fall into several of these categories. They range from simple systems with one manual applicator to highly complex, computer-controlled, automatic systems. They can incorporate hundreds of spray units. Automatic systems may have their applicators mounted on fixed stands, on reciprocating or rotating machines, on robots, and so on. 

In-line holography has been used to characterize the spray produced by a commercial rotary device a description of the optical system used to record and reconstruct the images has been given [74]. 

A mixture of air and a fine spray of gasoline at ambient (outside air) temperature is fed to a set of piston-fitted cylinders in an automobile engine. Sparks ignite the combustible mixtures in one cylinder after another, and the consequent rapid increase in temperature in the cylinders causes the combustion products to expand and drive the pistons. The back-and-forth motion of the pistons is converted to rotary motion of a crank shaft, motion that in turn is transmitted through a system of shafts and gears to propel the car. 

Figure 9 Disk-Coater fat coating system. Product is metered into a steam-coii heated chamber through a rotary iock feeder and is thrown off the upper rotating disk by centrifugai force. The particies faii through a thin spray of fat simuitaneousiy thrown off the tower rotating disk. Mixing and absorption are continued in the takeaway conveyor. Courtesy of ASIMA Corp., independence, Kansas.

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