High-efficiency Separator Research Articles

Calibration of flowmeters in superheated and wet steam

The vapour mass fraction (dryness fraction) of wet-steam flows such as those encountered in the steam main of a power or process plant will rarely be less than 90%. In flowmetering of high-quality saturated steam, the moisture content in the steam is allowed for by correcting the mass flow indicated by the steam flowmeter. Although there are a number of different ways of correcting the mass flow for water content, there is still doubt as to the methods used. In the work reported in this paper, three types of flowmeter were calibrated: first in superheated steam and then in an equilibrium wet-steam mixture to determine their wet-steam correction factors. The correction factors were found to be dependent on the types of flowmeter. For consistency with recommended practice, the method recommended by the ‘Shell Flowmetering Engineering Handbook’ (Ed. G. W. A. Danen, McGraw-Hill, 1985) can be used universally with reasonable accuracy provided a high-efficiency separator is placed upstream of the steam meter to increase the dryness fraction to above 95%.

High efficiency separators with string-type demisters

A new efficient separator design has been developed with a string-type demister. The demister is made up of packets consisting of series of vertical fibers that are positioned parallel to each other. These demisters have been tested in semicommercial and commercial equipment in treating natural and associated gases. The test results showed that the capacity of the string-type demister, for a given separation, is five times that of demisters made of knit screen and approximately twice that of vane-type separators. These data were used in the reconstruction of more than 20 currently operating oil-gas separators by replacing knit screen demisters by string-type demisters.

Update on Finish Grinding with Improved Energy Efficiency

Machinery and equipment suitable for retrofits in existing finish grinding systems and for new installations are described: adjustable diaphragms for ball mills to control the material transfer from the first to the second compartment; static separators for product separation from the mill vent air; dynamic high-efficiency separators for product separation, with and without recirculation of separation air; and high-pressure grinding rolls for pregrinding or for use in a closed circuit. For all equipment, operating results are given with respect to capacity and energy efficiency. These results clearly demonstrate that considerable improvements in existing grinding systems, as well as higher energy efficiencies of new grinding systems, can be accomplished with these features. Capacity increases of existing systems can easily reach 55-68 percent with higher energy efficiency of 25 or 30 percent. For new grinding systems, energy efficiency can be increased by 30 or 35 percent in comparison to the conventional closed-circuit ball milling system. The improved energy efficiency also has a positive influence on the cement quality.

Development of an advanced vaneless inlet particle separator for helicopter engines

Design and development of an advanced integral engine particle separator are presented to meet the challenging operational requirements of helicopter engines of the future. The vaneless, low-weight, high-efficiency separator makes it possible to achieve new levels of engine reliability, durability, and life cycle costs. This paper presents the analytical methods developed, the design process, and the extensive experimental validation of the design.

Increased Cement Grinding Efficiency by Using High-Efficiency Separators

High-efficiency classifiers improve the grain size distribution of the finished cement and reduce grinding power requirements. Theoretical calculations indicate potential power savings of up to one-third at the main mill motor when applying high-efficiency classifiers instead of conventional separators at a cement fineness of 15 percent residue at 0.030 mm. The most commonly used separators of conventional and high-efficiency design are presented and briefly characterized. Data on actual performance of grinding systems are stated which indicate that some 15 percent of the grinding system's power consumption can be saved when applying high-efficiency classifiers instead of conventional separators at 3500-4000 cm2/g (Blaine) cement fineness.