Batch Hot-dip Galvanized Pool Above The Exhaust Gas Collection Device Research And Numerical Simulation

With the increasing strict specification of civilian and government towords environmental protection, it is in urgent need to control and collect the waste gas produced during the process of general galvanizing. However, up to now, there is still neither specific device designed to collect the waste gas nor predecent method to diesign the device domestically.Simulating flow field of the waste gas flowing above zinc pot and studying of waste gas collecting devices for general galvanizing were finished in this paper. Starting with needs analysis of waste gas collecting device for the general galvanizing, the quality function deployment about the decice was finished by QFD tool, and the house of quality (HOQ) as a result of the process was also achieved. The result showed the main task and conflict in the design process. The three kinds of solutions to this task and conflict are proposed by the TRIZ theory and evaluated by fuzzy comprehensive evaluation (FCE) tool. Combined with the ventilation and air conditioning theory, the structure of waste gas collecting device for general galvanizing of the blowing-sucking style was designed. In addition, the flow fields of the three kinds of types of devices in operation were simulated by FLUENT software. Finally, four aspects of the new design theory and method of the wasete gas collecting device for general galvanizing were highlighted.First of all, during the program analysis stage, the kind of QFD/TRIZ/FCE innovative design model, which come form the process of general galvanizing device's QFD analysis, TRIZ tool analyses to the HOQ and the programs evaluation, was proposed. Secondly, base on the method of the static presses regain, the structure of waste of collecting device for general galvanizing of blowing-sucking style was proposed. The device can cover the waste gas from general galvanizing with uniform air curtain. Because the duct is designed to variable cross-section, the gas can be blown and sucked up evenly. As the result, the waste gas of general galvanizing is controlled effectively. Thirdly, according the FLUENT numerical simulation result of waste gas flowing above the zinc pot,130-230mm is a ideal height difference between blowing mouth and sucking mouth, the velocity of gas coming from blowing mouth is best between 9 and 12 meter per second.Fourthly, the relationship between the width of general galvanizing pot and the waste gas collecting methods is proposed. For example, the one-sided inflow device should be used to the zinc pot with a width less than 0.6 meter, and the two-sided inflow device is used to the zinc pot with a width between 0.6 meter and 1.2 meter. The blowing-sucking style collecting device would be a best choice when the zinc pot is over 1.2 meter wide.The theoretical analysis and practical design indicated that a method can be built up by adopting above mentioned theories and methods. And the method will help to found a rationale for the improvement of design of waste gas collecting devices for general galvanizing.