Showing papers on "Spray tower published in 2006"

Enhancement of Mass Transfer in a Spray Tower Using Swirling Gas Flow

Abstract: Spray towers are commonly used in the chemical and process industries for a number of applications including absorption, desorption and humidification. However, the main disadvantage of a spray tower compared with that of a packed tower is its lower contact efficiency. The present study is concerned with the enhancement of mass transfer between a continuous gas phase and liquid droplets in a spray tower by imparting swirl to the axial gas flow through the tower. It is well known that swirling flow has the ability to augment the rates of heat and mass transfer. Experimental investigations into the hydrodynamics and mass transfer in a laboratory-scale spray tower for air-NH3/H2O system using axial and swirling gas flows have been carried out. The hydrodynamic studies included measurements of the gas velocity distributions and overall pressure drop in the tower, and characterization of water sprays generated by a pressure-swirl nozzle where radial liquid distributions, droplet size and its distribution and mean droplet size in terms of SMD were measured. As for the mass transfer performance of the spray tower, the effect of the gas and liquid flow rates on the overall gas phase mass transfer coefficient, Kga, was investigated for both swirling and non-swirling axial gas flows in order to quantify the effect of swirl. It has been found that Kga increases with increasing gas/liquid flow rates and imparting swirl in the gas flow enhances Kga up to 20% compared with that in axial flows. Correlations of Kga as a function of the gas/liquid flow rates, and also as a function of the gas flow rate and initial droplets SMD are developed. A design methodology to determine the height of a spray tower required to achieve a specified amount of removal of a solute from a gas mixture is proposed.

Method and apparatus for improved gas/fluid contact

Abstract: A spray tower (20) for improving contact between a gas stream (22) and a fluid (24). The spray tower (20) includes a tank (26) having an inlet (32) and an outlet (34), and a plurality of spray nozzles (28) positioned in the tank, each of the plurality of spray nozzles including a spray outlet (38). Each of the plurality of spray nozzles (28) is adapted to spray a cone (40) of the fluid (24) through the spray outlet (38) into the tank (26). The spray tower (20) also includes a perforated plate (30) having a plurality of perforations (44). The perforated plate (30) is positioned in the tank (26) so as to define a cross-section of the tank and each of the plurality of perforations (44) is aligned with the cone (40) flowing from the spray outlet (38) of one of the spray nozzles.

Loop-circulation centrifugal atemizing dryer

Abstract: It's a loop-circulation centrifugal spray dryer, including a gas heating device, a centrifugal spray drying tower and a cyclone separator orderly connected, and a closed humidity discharging device, a spray tower, a condenser, a gas-liquid segregator and a closed blower orderly connected between the airflow outlet of the cyclone separator and the gas inlet of the gas heating device via a pipeline; the gas inlet of the gas heating device is also connected with the exterior inert gas providing pipe The utility model changes present thermal air into the thermal inert gas as the drying medium, and the inert gas is closed for cyclic usage, eliminating the factor of deflagration Because of the closed circuit, the harmful substance contained in the organic solvent is not easy to diffuse, which avoids air pollution and is favorable to environmental protection

Experimental and Theoretical Studies on Air Humidification by a Water Spray for Humid Air Turbine Cycle

Abstract: Humidification of compressed air is important for humid air turbine cycle. Earlier studies paid more attention to packed bed towers. However, a spray tower has inherent advantages such as less pressure loss and low cost. In this study, a pressurized model spray tower was established for the experiments. A specially designed air diffuser was installed to achieve uniform air velocity profiles over the cross section and a mist eliminator was used to trap the water droplets in the outlet air. Performance of the tower was tested at different pressures and water/air ratios. Pressure loss was measured and analyzed at different air velocities. A comprehensive analysis of the humidification process in the spray tower was carried out. A mathematical model considering droplet motion and conservation of heat and mass was developed to predict heat and mass transfer in the water droplet-air two-phase flow. Local heat and mass transfer coefficients over height of the tower were calculated. It has been shown that the parameters of outlet air and water can be calculated within a maximal error of 7.3% compared with the experiment results. Droplet size is a main parameter that affects operating performance of the spray tower. It has also been indicated that pressure loss in the spray tower is low and this will benefit its application in HAT.Copyright © 2006 by ASME

Apparatus for producing hydrate

Abstract: PROBLEM TO BE SOLVED: To produce hydrate having large particle diameter in a hydrate-producing apparatus. SOLUTION: In the hydrate-producing apparatus 10, an unreacted natural gas NG in a spray tower 12 is cooled and circulated by a gas circulation line 42. A gas feed line 36 is branched and the natural gas NG is fed to the spray tower in a state divided from the bottom of the spray tower 12 to the upper part of the tower 12. The natural gas NG forms stream which flows from the bottom to the upper part in the spray tower 12 and residence time of water W is prolonged by keeping whole height of a hydrate production area A of the spray tower 12 to ≥10 m. COPYRIGHT: (C)2006,JPO&NCIPI

Low pressure double flow spray method and system for high temperature fume quenching and tempering and dust processing

Abstract: The invention relates to a method for treating the low-pressure dual-flow spray high-temperature smoke modified dust. The method comprises: spraying to treat the high-temperature smoke inside the spray tower; the smoke is feed into the spray tower from the chimney; the spray tower uses low-pressure dual-flow spray to treat the high-temperature smoke; inside the spray tower, the high-temperature dust gas contacts the water frost sprayed by injector to be mixed and eliminate the sparkle in the high-temperature; the large grains of gas are directly discharged at the lower part of spray tower via the dedust function of water frost; the cooled gas via the channels enters into following dedusting process. The invention utilizes low-pressure dual-flow spray, to uniform the frost grain injected by the injector via the compressed air and water; reduces the time of vaporizing the smoke and the area of spray tower. And it has less area, reduced resistance and lower energy consumption.

Dust removing waste gas purifying spray tower

Abstract: The utility model relates to a dust removing waste gas purifying spray tower which is specifically used for purifying exhaust gas and removing dust in industries, such as metal refining, metal surface treatment, medicine food, electron, machinery manufacture, etc. The utility model mainly adopts the way that a filler layer is arranged in the tower body and a nozzle without blocking is installed on a spray frame; an exhaust cylinder is arranged on the tower body, and a circulating water supply system is connected with an interface of the spray frame on each layer; a circulating water pump is installed on a water pump base, and a tower body support frame supports the tower body. The utility model is characterized in that a settling tank is arranged under the tower body support frame; water seal is arranged in the settling tank; the water seal is communicated with the tower body, and a water absorbing opening of the circulating water pump is provided with a water inlet filtering net. The utility model has the advantage of simple, reasonable and compact structure. Because multi-stage spraying and multi-stage filler layers are adopted, exhaust gas can be sufficiently purified, playing the functions that the gas-liquid contact is sufficient, and the resistance is decreased to the minimum carrier. The atomization effect is good, and thick, medium and fine fog drops can be homogeneously sprayed. The nozzle has no blocking. The utility model can achieve the purposes of removing dust, purifying and saving water resource.

Desalination using spray tower and vapour compression refrigeration system

Abstract: A desalination system using a spray tower and Vapour Compression Refrigeration (VCR) system is proposed for obtaining fresh water from brackish water. In the spray tower, simultaneous heat and mass transfer take place between the brackish water and air, which results in the evaporation of the brackish water and humidification of the air. Fresh water is obtained from the humidified air by condensing the water vapour using a VCR system. Parametric studies were carried out to study the effect of various operational parameters on the fresh water production rate.