ISO 4174-1998 谷物、油籽和豆类 单维气流通过粮堆的单位压力损失的测量

标准号：ISO 4174-1998
中文标准名称：谷物、油籽和豆类 单维气流通过粮堆的单位压力损失的测量
英文标准名称：Cereals, oilseeds and pulses - Measurement of unit pressure loss in one-dimensional air flow through bulk grain
标准类型：B20
发布日期：1999/12/31 12:00:00
实施日期：1999/12/31 12:00:00
中国标准分类号：B20
国际标准分类号：67.060;67.200.20
适用范围：This International Standard specifies a method of measuring unit pressure loss in one-dimensional air flow through bulk grain, permitting calculation of the total pressure loss of a ventilation unit. This is equal to the sum of the pressure losses a) in the ventilation system (ducts, etc.); b) in the grain (which is the subject of this International Standard); c) due to the passage of the air from the duct into the grain. The pressure losses in the ventilation system and those due to the passage of the air from the duct into the grain can be considered as negligible in relation to the pressure losses in the grain if the air flow velocity does not exceed the following limits: — 8 m/s to 10 m/s in the main duct; — 4 m/s to 5 m/s in the secondary duct; — 0,25 m/s when entering the grain. If, for economic reasons, air velocities are higher than those indicated above (up to 30 m/s in the main duct), then, following pertinent literature, the pressure loss caused by the air distributing and discharging system has to be calculated.