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DEFINITIONS CONVERSIONS and CALCULATIONS for OCCUPATIONAL SAFETY and HEALTH PROFESSIONALS - CH4

Thông gió Chương này sẽ thảo luận về các thông số, đo lường, các mối quan hệ toán học, và các mảnh khác nhau của thiết bị, phần cứng, tạo thành khu vực nói chung của hệ thống thông gió. LIÊN QUAN ĐỊNH NGHĨA Thiết bị thông gió & Tham số cơ bản Thông gió là một hoạt động, theo đó không khí được di chuyển đến hoặc từ địa điểm khác nhau trong một cơ sở và / hoặc thông qua một loạt các phần khác nhau của thiết bị hoặc phần cứng. Lựa chọn từ nhiều loại thiết bị thông gió có. | Chapter 4 Ventnlatnon This chapter will discuss the parameters measurements mathematical relationships and the various pieces of hardware equipment etc. that constitute the general area of ventilation. RELEVANT DEFINITIONS Ventilation Equipment Basic Parameters Ventilation is an operation whereby air is moved to or from various locations within a facility by and or through a variety of different pieces of equipment or hardware. Selecting from the wide variety of available ventilation equipment will always be a function of the task that is to be accomplished. Tasks such as providing fresh air to a office removing vapors or fumes produced by some manufacturing process etc. are all recognizable objectives that can be readily achieved by the proper choice and operation of appropriate ventilation equipment. The various items of hardware and the factors and parameters that characterize each will be defined and described below. Hood A Hood is a shaped inlet designed and positioned so as to capture air that contains some sort of contaminant and then conduct this contaminated air into the ducts of the exhaust system. Hoods may be plain or flanged depending upon a variety of design factors. Flange A Flange is generally a flat piece of metal or rigid plastic that surrounds the shaped inlet of a hood and serves the purpose of minimizing the drawing of air from nearby zones where no contaminant is known or thought to exist. Capture Velocity The Capture Velocity is the air velocity at any point in front of a hood or hood opening that is necessary to overcome the opposing air currents and other factors and thereby capture the contaminated air at that point by causing it to flow or be drawn into the hood. Slot Velocity The Slot Velocity is the actual linear velocity of air as it enters a hood through its slot opening. Face Velocity The Face Velocity is the linear velocity of air averaged over the entire opening as it enters a hood. 1998 by CRC Press LLC. Coefficient of Entry The .