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Spray System (spray + system)

Distribution by Scientific Domains

Engineering	75%

Selected Abstracts

Experimental study on water spray suppression on burning upholstered chair in an enclosure with different application times

FIRE AND MATERIALS, Issue 5 2009
Q. Y. Xie
Abstract The objective of this work is to investigate the effects of the application time of water spray on the burning upholstered chair in an enclosure. A series of experiments are conducted with the same water flow rate in an ISO 9705 fire test room in which a water spray system is installed. Several identical upholstered chairs are used in the experiments with the application times 20, 25, 30, 40 and 45,s after the ignition of upholstered chair, respectively. The results show that there is nearly an exponential relationship between the peak heat release rates and the relative application times of water spray. It is also shown that there is a polynomial relationship between the relative time for the peak heat release rate and the relative application time of water spray. However, there is an exponential relationship between the whole relative extinguishing time and the relative application time of water spray. A sudden increase is detected before the decreasing of CO generation rates after the water spray is applied on the burning upholstered chair. The average temperatures of the upper hot smoke layer under the ceiling will generally be lower with the earlier application of water spray. Copyright © 2009 John Wiley & Sons, Ltd. [source]

CAD-based automated robot programming in adhesive spray systems for shoe outsoles and uppers

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11 2004
J. Y. Kim
Most shoe manufacturing processes are not yet automated; it puts restrictions on increasing productivity. Among them, adhesive application processes particularly are holding the most workers and working hours. In addition, the working environment is very poor due to the toxicity of adhesive agents. In the case of automating an adhesive application process by using a robot, robot teaching by playback is difficult to produce high productivity because the kinds of shoes to be taught mount up to several thousands. To cope with it, it is necessary to generate robot working paths automatically according to the kind, the size, or the right and the left of shoes, and also to teach the generated paths to a robot automatically. This paper presents a method to generate three-dimensional robot working paths off-line based on CAD data in an automatic adhesive spray system for shoe outsoles and uppers. First, this paper describes how to extract the three-dimensional data of an outsole outline from a two-dimensional CAD drawing file. Second, it describes how to extract the three-dimensional data of an upper profiling line from the three-dimensional scanning data that is opened in a three-dimensional CAD program. Third, it describes how to generate robot working paths based on the extracted data and the nozzle setting parameters for adhesive spray. Also, a series of experiments for adhesive spray is performed to verify the effectiveness of the presented methods. This study will do much for increasing productivity in shoe manufacturing as a core work of a robotic adhesive spray system. © 2004 Wiley Periodicals, Inc. [source]

A heuristic approach of calculating spray water flux needed to avert fire-induced runaway reactions,,

PROCESS SAFETY PROGRESS, Issue 3 2006
BChE (Honors), Dilip K. Das BSc (Honors), MSChE
In general all reactions have some heat effects. When the ability of the equipment to remove the heat is exceeded by the heat generated by a reaction, a hazardous situation called a runaway reaction may take place. Sometimes the exothermicity of runaway reactions is so high that the size of an emergency vent becomes impractical to install. A water spray system can sometimes be used to avert a fire-induced runaway reaction. Because the water spray system has a finite activation time, insulation helps to prolong the time required to reach the decomposition temperature. This article concludes that the required water flux to avert the fire-induced runaway reaction may be conservatively estimated by adding the water flux necessary to maintain an unbroken water film on the external surface of the equipment and the water flux necessary to absorb the fire heat after allowing for the splash loss and the in-flight loss. When adequate spray water is used, the metal temperature of the insulation jacket cannot theoretically exceed the boiling point of water thereby ensuring the avoidance of fire-induced runaway reactions whose adjusted onset decomposition temperature exceeds 100 ° C. Fire-induced runaway reactions with lower onset temperature can also be avoided depending on the initial temperature of the contents, mass of the contents and equipment, insulation thickness, and fire duration, for example, but a detailed calculation including dynamic simulation is necessary and the burden of proof lies with the designer. The reliability of the spray water system must be maintained high to include its credit as an environmental factor defined according to NFPA 30 to avoid the fire-induced runaway reaction as a scenario. Although API RP 521 does not allow any credit for sprinkler water, it allows credit, unlike NFPA 30, for insulation thickness and thus a runaway reaction can be avoided by using insulation alone according to API RP 521. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006 [source]