化学化工专业英语

本书特色

《化学化工专业英语》：全国高职高专化学课程“十一五”规划教材

内容简介

本书主要内容包括化工分析、化工单元操作过程、化工设备、石油化工、精细化工、高分子化工、煤化工等。选文侧重于实际工艺及技术操作，将基础知识与工程实际相结合。附录中设有常见酸碱盐、有机物的英文名称，常用英文化学分子式、方程式及数学式的读法，化学学科中的词缀、化学元素表、专业英语的翻译方法和技巧等。
本书可作为高职高专院校化学化工专业英语教材，也可供相关人员参考使用。

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插图：MeasurementThe predominant methods of measuring the properties of petroleum products are covered by approximately seven test methods that are used in the determination of bulk quantities of liquid petroleum and its products.Testing for suspended water and sediment is used primarily with fuel oils, where appreciableamounts of water and sediment may cause fouling of facilities for handling the oil and give troublein burner mechanisms. Three standard methods are available for this determination. The centrifuge method gives the total water and sediment content of the sample by volume, the distillation method gives the water only, volumetrically, and the extraction method gives the solid sediment in percentage by weight.The determination of density or specific gravity in the measurement and calculation of volume of petroleum products is important because gravity is an index of the weight of a measured volume of the product. Two scales are in use in the petroleum industry, specific gravity and API gravity, the determination being made in each case by means of a hydrometer of constant weight displacing avariable volume of oil. The reading obtained depends on both the gravity and the temperature of theoil.Gauging petroleum products involves the use of procedures for determining the liquid contents of tanks, ships and barges, tank cars, and tank trucks. Depth of liquid is determined by gauging through specified hatches or by reading gauge glasses or other devices. There are two basic types of gauges, in nage and outage. The procedures used depend on the type of tank to be gauged, its equip ment, and the gauging apparatus.[6]An in nage gauge is the depth of liquid in a tank measured from the surface of the liquid to the tank bottom or to a datum plate attached to the shell or bottom. The in nage gauge is used directly with the tank calibration table and the temperature of the product to calculate the volume of the product. On the other hand, an outage gauge is the distance between the surface of the product in the tank and the reference point above the surface, which is usually located in the gauging hatch. Theoutage gauge is used either directly or indirectly with the tank calibration table and the temperature of the product to calculate the volume of product. The amount of any flee water and sediment in the bottom of the tank is also gauged so that corrections can be made when calculating the net volume of the crude oil or petroleum product.There are also procedures for determining the temperatures of petroleum and its products when in a liquid state. Temperatures are deter minedat specified locations in tanks, ships and barges, tank cars, and tank trucks. For a non-pressure tank, a temperature is obtained by lowering a tank thermometer of proper range through the gauging hatch to the specified liquid level. After the entirethermometer assembly has had time to attain the temperature of the product, the thermometer is withdrawn and read quickly. This procedure is also used for low-pressure tanks equipped with gauging hatches or standpipes and for any pressure tank that has a pressure lock. For tanks equipped with thermometer wells, temperatures are obtained by reading thermometers placed in the wells with their bulbs at the desired tank levels.