摘要:

In the Introduction the author gives reasons for the slow adoption of the totally electrified sugar factory in the British Empire as compared with other parts of the world.A brief general description of the processes involved is then given; advantages and disadvantages are discussed and some comparison is drawn with steam-driven plants.The necessity of having a sugar factory specially designed for the all-electric drive is then stressed and details are given of the general layout of such a plant to obtain the maximum benefits of total electrification.A discussion then follows of the most suitable type of apparatus to employ, including notes on power-factor correction and maintenance routine.The paper concludes with examples of typical power consumption and cost of generating current.

DOI:10.1049/ji-2.1942.0048

出版商:IEE    

年代:1942

数据来源: IET

摘要:

The paper has the primary object of making known the application of electricity in the treatment of sugar beet through all the stages to the ultimate production of pure sugar. No claim is made by the author to have treated the subject in such a way that no more could be written; he has endeavoured to convey the idea of the main scheme of operation in the factory with which he is connected.It may be concluded that, although many factories in this country have applied electricity in the best manner possible within their limited expenditure, yet both in the factory and in the laboratory there still remains much room for further improvement. For instance, individual drives could be installed in many places where at present one large driving unit and line shafting now exist, and provided they are suitably interlocked—especially where elevators and conveyors work in conjunction—would prove a great advantage. Again, the sugar house should be equipped with the best type of sugar-spinning centrifugals. Much has been done by the manufacturers in conjunction with the users to improve this class of machinery.

DOI:10.1049/ji-2.1942.0049

出版商:IEE    

年代:1942

数据来源: IET

摘要:

Failures of insulation in service can be largely avoided by making field tests at regular intervals with suitable testing equipment. The paper deals with the field testing of the insulation of high-voltage switchgear, busbars and transformers, and describes the apparatus and methods employed by the authors on the Central Electricity Board's system.There are three main testing techniques: (a) the measurement of power factor; (b) the measurement of potential distribution; and (c) the measurement of insulation resistance; and practical testing equipments, designed to make such measurements and to satisfy the onerous conditions of field use, are described.Three wattmeter types of power-factor-measuring apparatus are described, two operating at 10 kV for bushing tests, and one operating at 50 kV for tests on busbar systems. Details are given of a modified form of bridge specially developed for field testing. The measurement of the potential distribution on bushings under service conditions is discussed, and reference is made to an electronic testing set for the measurement of insulation resistances up to 10 000 megohms at 5 000 V.More than 2 000 tests have been made on installed apparatus, and the results obtained are summarized. Twenty-four faulty bushings have been located by test and taken out of service before breakdown. Special test methods are described in order to facilitate making power-factor measurements on transformer bushings and orifice insulators.Information is also given on the power factor of oil in service.Methods are suggested of continuously supervising the insulation of important installations in cases where the low-voltage end of the insulators can be isolated from earth.Finally, the merits and demerits of the three main test methods are summarized in order to assist the maintenance engineer in choosing the method or methods which will best fulfil his requirements.

DOI:10.1049/ji-2.1942.0052

出版商:IEE    

年代:1942

数据来源: IET

摘要:

The paper discusses the considerations affecting the management of protective gear on power supply systems.In Section (2) the extent of the responsibilities and the qualifications of protective-gear engineers is reviewed.A number of simplifying assumptions which can be made when calculating power-system fault currents and voltages are given in Section (3). This Section also discusses system abnormalities other than faults, and their relationship to protective-gear operation.Section (4) mentions certain characteristics of protective gear which affect its performance and correct application.A general outline of the work which should be carried out on protective gear before commissioning is given in Section (5). Detailed consideration is then given to the way in which this work should be carried out on various types of gear. A description of general methods of testing and of testing-equipment follows in Section (6).Section (7) is devoted to consideration of protective-gear troubles and routine maintenance procedure.Finally, in Section (8) certain features of protective-gear design, construction and layout which assist maintenance are discussed.

DOI:10.1049/ji-2.1942.0055

出版商:IEE    

年代:1942

数据来源: IET

摘要:

The paper explains the nature and primary importance of annealing processes as applied to commercial glassware, with particular reference to bottles and containers.Development stages, from heated brick arches to portable and continuous lehrs, are described in the section on mechanical improvements. The application of controlled heat to the fused and moulded product is shown through the transition stages of coal, producer-gas and oil firing, to complete electrification of annealing lehrs. Insulation factors and methods; heat conservation and re-application; cooling gradations; economic and product quality considerations in favouring the application of electricity as a power and heating element, are all made subjects for explanatory data. A brief account is given of tumbler-edge glazing and enamelling, which involve the processing of pre-annealed cold ware.

DOI:10.1049/ji-2.1942.0058

出版商:IEE    

年代:1942

数据来源: IET

摘要:

An instrument is described which gives a rapid indication of the peak factor (peak/r.m.s.) An electrostatic voltmeter is connected to give readings proportional to the r.m.s. voltage. When the reading is steady, operation of a press-key introduces a rectifier into the circuit for peak voltage, and in the case of alternating current also introduces by a tapping 1/√2 times the applied voltage, so that the voltage applied to the voltmeter is the same as for the r.m.s. position if the wave form is sinusoidal. In this case no pointer movement occurs and the scale may be calibrated as for 1.41 peak factor. Other peak factors may be added directly from the voltage scale.The application to rectified and smoothed direct current is also proposed, “pure” direct current having a peak factor of unity. It is further proposed that “impure” direct current may be specified by its peak factor rather than by the “ripple,” as no standard is laid down for the term “ripple.”Conditions of use are considered and possible errors examined. The instrument is inherently accurate, as the voltmeter scale is used for both peak and r.m.s. readings and scale errors thus tend to cancel out.Tests have borne out the theoretical considerations.

DOI:10.1049/ji-2.1942.0060

出版商:IEE    

年代:1942

数据来源: IET