Separate Compressor Research Articles

Syllabically compandinglog domain filter usingdynamic biasing

It is shown that syllabic companding in a log domain filter can be accomplished by varying the bias currents, thus eliminating the need for separate compressor and expander blocks. The advantages of the proposed technique are discussed.

A parametric study of recycle membrane separators

The performances of recycle membrane permeators with feed introduced to the high-pressure side (recycle stripper) and to the low-pressure side (enricher recycle) were compared by numerical simulation over a range of membrane area to feed flow rate ratios. The effect of permselectivity on the performance of the recycle permeator for either feed arrangement was also examined. The results showed that an enricher recycle always performed inferior to a recycle stripper both in terms of Rony's separation index and compressor requirements.

Digital signal processing syllabic compander

AbstractAt present, analog circuits are used widely for syllabic companding which effectively improves the quality of speech communication. The digitalization of the syllabic companding circuit promises several advantages, namely, the possibility of adapting filter coefficients to the condition of the radio communication system, the elimination of adjustments, the possibility of large‐scale integration, etc. The present paper considers such a new approach, a digital signal processing syllabic compander. The realization method is described and the results of both theoretical and computer aided investigations concerning the characteristics of the compander are presented. First, the construction of the digital signal processing compander is shown. Then detailed theoretical investigations are given on the influence of the distortion which is a specific problem of the digital realization. The results obtained agree well with those of the computer‐aided analysis. According to the investigations presented it has become clear that the sampling frequency should exceed 24 kHz in order to attain a signal‐to‐distortion ratio of above 40 dB in the voice frequency band for a separate compressor and an expander. However, if the compressor and expander are connected in a system, then a distortion cancellation effect arises which allows a considerable reduction of the sampling frequency. The transient response has also been investigated, and the same characteristics have been obtained as in the case of analog companders.

The solution to the gas turbine temperature problem

All previous Brayton cycle engines have utilized a separate compressor and expander and thus have been limited in temperature on the expander side. To overcome this limitation, the author has designed a new, rotary positive displacement Brayton type engine in which each mechanism both compresses and expands the working fluid. Since each mechanism goes from cold to hot and back to cold, the material will remain at approximately the mean temperature of the compressed and expanded gas. Thus much higher temperatures can be used—with much less expensive materials. The mechanism is also unique in that the rotor is offset from the center of the stator so that the expansion volume is greater than the compression volume. Computer simulation indicates that the overall efficiency of the engine will be 57%, weight will be 4.4482 N/bhp (11b/bhp), and emissions of HC and CO lower than any proposed standard. The engine promises twice the fuel economy, half the maintenance, and three-fourths the first cost of the conventional Otto cycle engine.

PNEUMATICS — AN ANALYSIS FOR AUXILIARY POWER USE

ABSTRACTThis paper presents a description of a pneumatic system as an alternative to electric power for driving auxiliary pumps. An analysis is made which compares the supply and demand of such a system aboard a gas turbine propelled destroyer. Sources of air supply are evaluated and compared with pumping power demands. The suitability/payoff/penalty associated with separate (motor driven) compressor, engine driven compressor, and simple engine bleed are evaluated. A source of air is chosen and then used in a total ship “trade‐off” between pneumatic and electric sea water pumps.A second analysis is presented along similar lines which compares pneumatics with 60Hz and 400Hz power alternatives on a Surface Effect Ship. Comparisons are made in weight reduction of alternative design options.Finally, a discussion is presented regarding the suitability of the “pneumatic concept” as it pertains to Navy shipboard use. Conclusions are reached which indicate where the concept has its most attractive application.

A new plate for internal fixation—the dynamic compression plate (DCP)

A system of internal fixation of fractures is presented in which two new principles are introduced simultaneously. Titanium is adopted as the material for the plates and screws by virtue of its corrosion resistance and because its elasticity is nearer to that of bone than is that of stainless steel. The second new principle is the provision of sloping cylind-rical oval holes in the plate, so that driving home the spherical-headed screws applies compression without the need for a separate compressor. A system of internal fixation of fractures is presented in which two new principles are introduced simultaneously. Titanium is adopted as the material for the plates and screws by virtue of its corrosion resistance and because its elasticity is nearer to that of bone than is that of stainless steel. The second new principle is the provision of sloping cylind-rical oval holes in the plate, so that driving home the spherical-headed screws applies compression without the need for a separate compressor.

Month in the Patent Office

A helicopter rotor wherein each blade 3 carries a tip propulsion‐jet unit 4 has each unit constructed to reduce the velocity and noise level of the propulsive jets. Each unit 4 consists of an outer casing formed into a double wall at its forward end to provide an annular duct 12 which communicates through an aperture 20 with a conduit which extends through each blade from a gas producing plant 22, consisting of a gas turbine engine or engines or a separate compressor driven by such engine(s). Arms 10 secured radially on the forward end of the fairing support a central faired body 9 which is connected at its rear end to the fairing by stator blades 18 mounted ahead of a bladed rotor 5 secured in body 9 by a bearing 11. Blades 6 of rotor 5 carry a shroud ring formed on its periphery with turbine blades 8. Further stator blades 14, 15 connect the casing 4 to a tail fairing cone 16 and stator blades 13 bridge the duct 12. In operation gas flow from the blade conduit passes into duct 12 to be directed over blades 8 to drive rotor 5 which draws air through the unit to mix with the gases from gas producing plant 22 with a consequent reduction in jet velocity and noise. Any one of the rows of fan rotor and stator blades may be angularly adjustable to control the rotor speed. Alternatively, the turbine rotor blades 8 may be of the impulse type and a variable area admission nozzle used.