摘要:

The subject matter of this paper is divided under the following headings:Introduction;Natural-circulation boilers;Directly-heated forced-circulation boilers;Indirectly-heated boilers;Special-effect boilers;Conclusion;Acknowledgments;References.Introduction.Some data are presented to show the rate of increase in cost with rising pressure for arrangements of boilers, superheaters, economizers, and air heaters, both stoker-fired and pulverized-fuel-fired, with increase in final steam temperature and, alternatively, with reheat.The effect of feed-water temperature on the extent of boiler, economizer, and air preheater surface is also discussed.The codes in force governing the thickness of boiler tubes and the methods adopted for fabrication of high-pressure steam drums, are referred to.Natural-Circulation Boilers.Boiler units installed for high-pressure service since 1920 have been listed according to the steam cycles on which they are operated.Some descriptions are given of some of the plants from each of the five tables which have been prepared.Directly-heated Forced-Circulation Boilers.Consideration is given to the Benson boiler and to the “Once Through” series boiler, as being the most advanced of this type.Indirectly-heated Boilers.Some particulars of the Schmidt and Loffler boilers are given.Special-effect Boilers.The majority of these are experimental only: the Atmos boiler is described.

DOI:10.1049/jiee-1.1933.0067

出版商:IEE    

年代:1933

数据来源: IET

摘要:

The paper gives a general description of the manufacturing processes used in the production of rough synthetic corundum and of jewel bearings for electricity meters and other measuring instruments.In Part 1 of the paper typical characteristics are illustrated which are peculiar to natural and synthetic sapphires, to show to what extent the lack of homogeneity of the material can impair its qualities as a bearing.Part 2 deals with the production of synthetic rough sapphires. Reference is made to the method and the apparatus now employed for the synthesis of sapphire.In Part 3 the manufacture and design of jewel bearings is described in a general way, and some special characteristics of corundum are given.

DOI:10.1049/jiee-1.1933.0069

出版商:IEE    

年代:1933

数据来源: IET

摘要:

This paper, which is an abridgement of a report† prepared by the E.R.A., deals briefly with the most important aspects of the resistance of electrodes used for earthing electrical installations and apparatus. After comparing the practice in various countries, details are given of the effect of the resistivity of the soil and the size and lay-out of electrodes on their resistance. It is shown that in order to have a low resistance the electrodes should cover a large area by consisting of either strips or, alternatively, a number of small electrodes connected in parallel. To facilitate the latter arrangement it is recommended that driven rod or pipe electrodes be used. A low resistance may also be obtained by salting the soil around electrodes, and this is considered together with the effect of using coke breeze.

DOI:10.1049/jiee-1.1933.0071

出版商:IEE    

年代:1933

数据来源: IET

DOI:10.1049/jiee-1.1933.0072

出版商:IEE    

年代:1933

数据来源: IET

摘要:

The paper deals with the stabilized high-frequency amplifier, with special reference to power amplifiers for wireless transmission purposes.Part 1 gives a brief sketch of the historical development of the high-frequency amplifier, in which the contributions of Miller and Nichols to the understanding of the nature of the problem, and those of Hazeltine, Rice, and others to its solution, are discussed.Part 2 contains a discussion of the balanced bridge in relation to valve circuits, in which the effects of stray coupling, circuit unbalance, and asymmetry of driving potentials upon the stability of bridge-circuit amplifiers, are considered. Methods of obtaining a neutralizing balance and devices for reducing the effective anode-grid circuit couplings are described.Part 3 gives an account of some experiences met with in the experimental development of a two-stage power amplifier developed by H.M. Signal School, Portsmouth, for naval ship use as a wireless transmitter.Part 4 contains a brief description of the transmitter and some design details.

DOI:10.1049/jiee-1.1933.0073

出版商:IEE    

年代:1933

数据来源: IET

DOI:10.1049/jiee-1.1933.0075

出版商:IEE    

年代:1933

数据来源: IET

DOI:10.1049/jiee-1.1933.0077

出版商:IEE    

年代:1933

数据来源: IET