* GB785333 (A)

Description: GB785333 (A) ? 1957-10-23

Improvements in or relating to high frequency amplifiers and oscillators

Description of GB785333 (A)

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PATENT' SPECIFICATION 785,333 Date of Application and filing Complete Specification May 23, 1955. No 14754/55. Application made in France on June 10, 1954. Complete Specification Published Oct 23, 1957. Index at Acceptance:-Classes 3 C( 1), D 4 (A 1 A 7: II 15 F 6 B X 3), 1 D(l Oi:io 161: 34); and 40 ( 6), A( 1 R: 2 V: 5 V 6-T), 02 (A 8: EIS E 3 C: F 3). International Classification: -H Olj H 03 b, f. COMPLETE SPECIFICATION Improvements in or relating to High Frequency Amplifiers and Oscillators We, COMPAGNIE GENERA-LE DE _ ELEGRAPHIE SA Ns FIL, of 98, bis Boulevard Haussmann, Paris ( 8), France, a French body corporate do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be

particularly described in and by the following statement:- Thlis invention relates to amplifiers and oscillators for use on very high frequencies for example on frequencies of the order of from 1 Mc/s to several hundred Mc/s and has for its object to provide improved amplifiers and oscillators capable of operating at a very narrow frequency band which can be readily adjusted by electrical means to be anywhere within a very wide frequency band. The invention provides improved amplifiers and oscillators of the so-called "tunable distributed amplifier " type In this now well known type of amplifier use is made of two similar delay lines, each usually terminated at both ends by resistances equal to their characteristic impedances, and of a number of valves having their anodes tapped at points along one line and their control grids similarly tapped along the other line Input signals to be amplified are applied near one end of the line to which the grids are connected and amplified output is taken from near the other end of the line to which the anodes are connected. Obviously if sufficient output is fed back to the input in the correct phase, oscillation generation will occur and the device becomes an oscillator. In known tunable distributed amplifiers the delay lines connected respectively to the grids and to the anodes of the valves employed remain alike as regards their constants of phase propagation, irrespective of the frequency of the input Accordingly the known distributed amplifiers are essentially wide band devices. The present invention seeks to improve the known distributed amplifiers and oscillators to the extent of giving them narrow band properties while enabling them to be electrically tuned lPrice 3 s 6 d l over a wvide band of frequencies The object is achieved, according to the invention in its broadest aspect by replacing either of the two lines of a known distributed amplifier (i e. either the line to which the anodes are connected or the line to which the grids are connected) by a phase displacement device having a constant of phase propagation and whose said constant can be adjusted over a desired range of values By adjusting the said constant of phase propagation to be the same at that of the said other for a given frequency, the amplifier may be made to operate over a narrow band centred on that frequency and the position of the narrow band can be adjusted over a wide band by adjusting the constant of phase propagation of the phase displacement device. A feature of the invention is the use in amplifier of a novel discharge tube device specially adapted to serve as a phase displacement device whose constant of phase propagation may be readily adjusted electrically.

The invention is illustrated in the accompanying drawing which shows schematically and diagrammatically one embodiment thereof. A plurality of valves, as shown three pentodes 1, 2 and 3, have their anodes connected to different tappings along a delay line 11, which, in the example illustrated, consists of an inductance winding 5 and shunt capacities provided by condensers 6 supplemented by the self-capacities of the valves In some cases the shunt capacities may be constituted entirely by the self-capacities of the valves The line is closed at both its ends on resistances 7 dimensioned to provide impedance matching over the desired working frequency band so that wave reflections will not occur from the line ends The screen grids and anodes of the valves receive suitable positive operating D C. potentials from a source (not shown) connected at terminal 12 through suitable filters 13 The value of the matching resistance 7 at the end of the line near which the D C. potential is applied must be chosen with due regard to the impedance of the D C source 2 785,333 connected at terminal 12 since, of course, this source is virtually in parallel with resistance 7. Suitable bias is applied to the valve cathodes from a negative D C supply source (not shown) connected at terminal 14. If the arrangement were of the usual known form of distributed amplifier the control grids of the valves 1, 2 and 3 would be tapped along a second line similar to the line 11 In accordance with this invention, however, this second line is replaced by a phase displacement element with electronic control, said element being constituted by a discharge tube 4 comprising an envelope 15 within which are two discharge space portions In the first of these electrons of a beam 33 emitted by a cathode 16 and controlled in density by a control grid 17, pass through a first accelerating anode 18 after which they are subjected to deflection by deflection means exemplified by a pair of electrostatic plates 19 between which is applied a deflecting potential supplied by a source 20 and adjustable as indicated conventionally at 21 The electron beam then passes through a second accelerating anode 22 the said beam now being at an angle both to the axis of the first discharge space portion and to the axis of the second discharge space portion which is shown as at right angles to the axis of the first space The second discharge space portion is threaded by a longitudinal magnetic field produced by solenoid 23 wound round the envelope of this portion In this second space portion is a number of grid electrodes 24 (the term " grid " here means an electrode through which the beam can pass in coupling relation-not necessarily an actual wire grid) said number being one less than the number of valves tapped along the line 11 As shown, since there are three valves ( 1, 2, 3) there are two grid electrodes shown as

perforated plates In addition there is a plate electrode The spacing between adjacent control electrodes 24 and that between the plate electrode 25 and the nearest electrode 24 is the same, the arrangement being such that the tappings to the device are distributed in correspondence with the tappings along delay line 11 i e the tappings along the phase displacement device are so chosen that at the timed frequency the constant of phase propagation (either electromagnetic or electronic) between these is equal to the constant of phase propagation of the wave between corresponding tappings on the delay line The valves 1, 2, 3 have their control grids connected to the electrodes 24, 25, each to each as shown, the inter-connections being maintained at substantially the same potential as the accelerating anodes -18 and 22 (earth potential in the case shown) through leads including resistances 26. It may be noted that a tube somewhat similar to the tube 4 is described by E Labin in " Onde Electrique " for February 1951 (Figure 2, page 83) but the tube 4 differs from the one there described by the presence of the grid electrodes 24. Cathode 16 is negatively biased by a D C. source 27 and the control grid 17 is negatively biased by a D C source 34 through a resist 7 u ance 28 An input signal to be amplified is applied to the control grid 1 ? from terminal 29 through condenser 30 and the amplified signal output is taken oft from a tapping near the end of the line 11 adjacent valve 3 through 7 a condenser 3 i to an output terminal 32. This arrangement operates as bollows:Beam 33 is modulated in intensity by the signal applied to the control grid 17 and is then deiiected by the plates 19 by an angle, o dependent on the potential between said plates, i e upon the position of the adjustment 21 where G, is the angle subtended between the axis of the beam from 16 when undeflected and the axis after deflection by plates 19 as 55 indicated in the figure It accordingly enters the equipotential space-the second discharge space portion-containing electrodes 24 and at an angle oi 90-7 to the axis of this space As a result of tnis angle of entry in ku combination with the action of the applied axial magnetic field produced by the salenoid 23, the electrons follow a substantially helical trajectory the pitch of which and, consequently tne developed length of which, depends upon 95 the angle x The electron transit time and, with it, the t Ltriais separating tlne passages of a given paase of the modulation across the grids 214 and up to the plate 23, can therefore be varied oy varying the adjustment 21 100 "ccordi Lgiy it is possible to pick-up on the resistances 26 and apply to the control grids of the valves 1 to 3, a signal corresponding to the signal received at the input but with a

constant phase displacement from one control 195 grid to the next, this phase displacement being regulatable by the adjustments 21 For a certain setting of this adjustment only one input frequency will be amplified (or at any rate only a narrow frequency band centred on 110 this frequency) namely that frequency for which the phase displacement in each successive portion of line 11 (the portion between two adjacent anode connection taps) will be equal to the phase displacement effected 115 between the corresponding pair of control grids 24 This narrow band can be moved at will over a wide frequency band by control of adjustment 21, the said wide band having a width corresponding to that which a known 120 distributed amplifier using two lines like the line 11 would pass. The invention is not limited to the example described and illustrated The electrically controllable phase displacement tube shown 125 could be replaced by another controllable phase displacement device adapted to give the same result Moreover, instead of tapping the valve control grids on the controllable phase displacement device and the valve anodes on 130 785,333 785,333 3 the line, the anodes could be tapped on the device and the control grids on the line. Furthermore, although the invention has been shown as employed for amplification purposes, it is obvious that such an amplifier can be easily converted into an oscillator by establishing feed back coupling of appropriate extent and phase between the output and the input. Such an oscillator would oscillate sharply at a frequency which could be adjusted over a wide band by adjusting the angle a at which the electron beam enters the second discharge space portion of the tube 4 i e by adjusting control 21 In the claims which follow the term amplifier is used in a broad sense to include an oscillator, an oscillator being, for present purposes, merely an amplifier backcoupled so as to maintain oscillations.

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* GB785334 (A)

Description: GB785334 (A) ? 1957-10-23

Improvements in or relating to cyanine dyestuffs

Description of GB785334 (A) Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

AMENDED SPECIFICATION Reprinted as amended under Section 8 of the Patents Act, 1949. PATENT SPECIFICATION Inventors: HENRY RICHARD JOHN WADDINGTON, GEORGE FRANK DUFFIN and JOHN DAVID KENDALL 785,334 Date of filing Complete Specification: April 3, 1956. Application Date: May 23, 1955. No 14878/55. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Classes 2 ( 3), B 4 (A 1: H: K), CIG( 5 A: 5 B: 6 B 4: 6 B 5), C 3 A 13 C(l C: 1 OF); 2 ( 4), D 1 Q; and 98 ( 2), C 3. International Classification:i-CO 7 d C 09 b G 03 c. COMPLETE SPECIFICATION Improvements; in or relating to'Cyanine Dyestuffs We, ILFORD LIMITED, a British Company, of 23 Roden Street, Ilford Essex, England, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to cyanine dyestuffs and particularly to cyanine dyestuffs which are of value as sensitisers for photographic silver halide emulsions. According to the present invention cyanine dyestuffs are obtained by reacting a terazole quaternary salt of the general formula I: N N R 2 N 6 I g C CH 3 a, X where R, is an alkyl or hydroxyalkyl group, R 2 is a cycloalkyl group-or an aryl group, substituted by groups other than alkyl, and X is an acid radicle, with a 5-membered or 6membered heterocyclic nitrogen compound of the formula II:9 -C (Z CH), N R 3 Y II where m is 0 or 1, R 3 is an alkyl or hydroxyalkyl group, Y is an

acid radicle, Z is -CHI= or -N=, D, is the residue of a 5-membered. or 6 membered heterocyclic nitrogen compound and Q is a thioether (-S), thioether lPrice vinyl (-CHI= CCH-SR) (R being alkyl or aralkyl), or acetanilidovinyl grouping, or with a heterocyclic nitrogen compound of the formula III:,-D 2 " R 400 d NC C -Go III where R 4 is alkyl and D, is the residue of a heterocyclic nitrogen ketomethylene nucleus. The tetrazole base could theoretically give four possible salts That the product is of formula I is shown by the following evidence 1Phenyl 5 methyl tetrazole and methyl iodide give a quaternary methiodide which is converted by the action of boiling 50 % aqueous potassium hydroxide (see Duffin et al, Chem. and Ind 1954, 1458) into methylamine and phenyl azide which products are easily seen to result from the degradation of a compound of formula I but not from any alternative formula which might be considered possible. The products according to this invention have one or other of the following general formula IV and V: ?N N 2 Dj I I N C -CH (CH CH), C (Z CH)m N P 3.1 R-3 X IV N N R 2 D 2N C m CH CH C O R, In the foregoing formulae R,, R 2, R, X, Z, mn, D, and D 1 have the meanings assigned to them above, and X is nought or 1. It will be appreciated that the foregoing J products are written in the form of one resonance extreme but in fact may exist in three different resonance extreme forms. Where in the foregoing formulae alkyl groups are referred to these are preferably methyl or ethyl groups, but they may be higher alkyl groups Where substituted aryl groups are employed these may be phenyl substituted with halo or -alkoxy groups The group R, may contain a hydroxy substituent, e g fl-hydroxyethyl. X and Y may be any acid radicles, for example halide (chloride, bromide, iodide), sulphate, sulphamate, perchlorate or p toluene sulphonate. D 1 may be the residue of any five-membered or six-membered heterocyclic ring system including thiazoles, oxazoles, selenazoles and their polycyclic homologues such as those of the benzene or naphthalene series; pyridine and its polycyclic homologues, such as quinoline and 7 and j( naphthoquinolines; indolenines; diazines such as pyrimidines and quinazolines The polycyclic compounds of these series may be substituted in the carbocyclic rings with one or more groups such as alkyl, aryl, alkoxy and methylene dioxy groups, or by halogen atoms. D 2 may be the residue of rhodanic acid ( 2thio 4 keto tetrahydrothiazole) and the substitution derivatives thereof, pyrazole 5ones, oxazolone and thiazolidone.

The reaction is preferably carried out by heating the reagents together in the presence of an acid binding agent, examples of which are pyridine, triethylamine and sodium acetate. Where a compound of formula II is to be employed which is a quaternary salt, and R 1 and R 3 are same in value, it is convenient to effect the reaction by fusing together a base corresponding to the compound of formula I and a base corresponding to the compound of formula II together with sufficient salt to convert both compounds to the quaternary salts. After such fusion the mixture may be heated with an acid binding agent to complete the reaction Intermediate of formula II suitable for use in the present invention are for the most part well known compounds and all may be made by methods well known per se. Instead of using a compound of formula III there may be employed a compound of the formula VI:CET 2 Co together with a substantially molecular equivalent amount of an alkyl orthoformic ester, e g. ethyl orthoformate. The dyestuffs obtained are new chemical compounds and have in general the property of sensitising photographic gelatino silver halide emulsions such as silver chloride and 65 iodobromide emulsions They may be added to such emulsions in the amounts commonly used in the art for sensitising such emulsions with cyanine dyes. Examples serving to illustrate the invention 70 are set out below, but for convenience there is first set out the methods employed for the preparation of the tetrazole intermediates used in these Examples All temperatures are in C 75 The following compounds were prepared from the appropriate starting materials by a method similar to the method of Dimroth and de Montmollin, Berichte, 43, 2908 ( 1910). 1 in Chloropkenyl 5 methyltetrazole 80 As buff coloured needles, m pt 1050, from benzene/petroleum ether ( 60-800). 1 o Cilorophlenyl 5 methyltetrazole. As buff coloured needles, m pt 820, from benzene/petroleum ether ( 40-600) 85 1 p Briawopliezyl 5 inethyltetrazole. As buff coloured needles, m pt 1190, from ethanol. 1 Cyclohexyl 5 methyltetrazole and 1 p anisyl 5 methyltetrazole were 90 prepared according to the method of Harvill, Herbst, Schreiner and Roberts (J Org Chem, 15, 666 ( 1950)). The following quaternary salts were made by reaction of the bases with methyl iodide 95 4:5 Dimethyl 1 m chlorophenylterazolium iodide As white micro-needles, m. pt 1680 (d), from ethanol. 4:5 Dimethyl 1 o chlorophenylterazolium iodide As pale yellow prisms, m 100 pt 1650, from acetone. 4:5 Dirnethyl 1 p bromophenyltetrazolijun iodide As white needles, m

pt. 2080 (d), from ethanol. 4:5 Dirnethyl 1 cyclohexyltetrazolium 105 iodide As white needles, m pt 2190 (d), from ethanol. 4.5 Dinietltyl 1 p anisyltetrazolium iodide As white needles, m pt 1950, from ethanol 110 EXAMPLE 1 1 m Chlorophenyl 4 methyl 5 tetrazole) ( 1 ethyl-4-quinazoline) monomethine cyanine perchlorate. 4:5 Dimethyl 1 m chlorophenyl 115 tetrazolium iodide ( 0 67 g), 1 ethyl 4ethylthioquinazolinium iodide ( 0 69 g), pyridine ( 5 ml) and refluxed for one hour After and refluxed for one hour After pouring the yellow solution into 4 % aqueous sodium per 120 chlorate, filtering the precipitate and recrystallising it from ethanol, the pure dye was obtained as yellow needles, m pt 1830. 1 Ethyl 4 ethylthioquinazolinium iodide used in this Example was prepared by heating 125 4 ethylthioquinazoline (British Patent No. 785,334 785,334 425,609) ( 5 g) with ethyl iodide ( 10 ml) under reflux for 24 hours After cooling and adding acetone the mixture crystallised as yellow needles Recrystallisation from acetone gave the pure ethiodide as yellow microneedles, m pt 1370. EXAMPLE 2 ( 1 m chlorophenyl 4 methyl 5 tetrazole) ( 3 ethyl 2 benzolthiazole) trimethincyanine iodide. 1 m chlorophenyl 4: 5 dimethyltetrazole iodide ( 0 67 g), 2 21 acetanilidovinyl 3 ethylbenxothiazolium iodide ( 0 9 g.), pyridine ( 5 ml) and triethylamine ( 1 0 ml) were boiled under reflux for 1 hr On pouring into 4 % aqueous sodium iodide, a red solid was precipitated which was recrystallized from ethanol to give the pure dye as red plates, m pt 1860 (d) This dye extends the sensitivity of a silver chloride emulsion to 5650 A with a maximum of 5200 A. The dyes of the formula:UN N R 2N-C -OH-OH OH a-N CH 3 R 3 I were prepared by the general method of Example 2. No R 2 D 1 is residue of R, m pt form Emulsion Extent Maximum 3 m-Gl CH 4 2-benzoxazole Ethyl 2190 orange Ag Cl 5250 A 4800 A (d) needles (b) 4 p-CH 3 OCGH 4 2-benzoxazole Ethyl 1430 brown Ag Gl 5200 A 4800 A (d) needles (a) p-CH 3 OC H 4 2-benzothiazole Ethyl 198 brown Ag Gl 5600 A 5150 A (d) needles (b) 6 p-CH 3 O Ce H 4 3:3-dimethyl-2 Methyl 2050 red Ag GI 5450 A 5000 A indolenine (d) needles (b) 7 o-CIC 6 H 4 2-benzothiazole Ethyl 2090 brown Ag CI 5600 A 5200 A (d) needles (b) 8 o-CICH 4 3:3-dimethyl-2 Methyl 2200 purple Ag Cl 5400 A 5000 A indolenine needles (a 9 p-Br CH 44 2-benzotliazole Ethyl 2240 red Ag Gl 5650 A 5200, A (d) needles (b) (a) from water (b) from ethanol -c 4 r. solution was poured into 4 % aqueous sodium perchlorate A yellow solid was precipitated which was filtered off and recrystallized from

ethanol to give the pure dye as yellow needles, m pt 1860. EXAMPLE 13 ( 1 p anisyl 4 methyl A 2 '' 5tetrazolinylidene) ethylidene 3 ethyl 2thiothiazolid 4 one. 4: 5 Dimethyl 1 p anisyltetrazolium iodide ( 0 66 g), 5 ethoxymethylene 3 ethyl 2 thiothiazolid 4 one ( 043 g), pyridine ( 5 ml) and triethylamine ( 1 0 ml) were boiled under reflux for 1 hr to give a red solution On pouring into water ( 50 ml) a red solid was precipitated which was filtered off and recrystallized from ethanol to give the pure dye as red needles, m pt 2180 This dye extends the sensitivity of a silver chloride emulsion to 5700 A with a maximum at 5200 Ar. The dyes of the formula: N N a R 2 D?, "N C CH CH = C CO Re were prepared by the method of Example 13. EXAMPLE 10 ( 1 Cyclohexyl 4 methyl 5 terazole) ( 3 ethyl 2-benzothiazole) trimethincyanine perchlorate was prepared by the method of Example 2 as brown prisms, m pt 234 from methanol. This dye extends the sensitivity of a silver chloride emulsion to 5450 A with a maximum of 5100 A. EXAMPLE 11 ( 1 Cyclohexyl 4 methyl 5 tetrazole) ( 3: 3 dimethyl 2 indolenine) trimethincyanine perchlorate was prepared by the method of Example 2 as red prisms, m pt. 1370 from methanol. This dye extends the sensitivity of a silver chloride emulsion to 5250 A with a maximum at 4900 A. EXAMPLE 12 ( 4 Methyl 1 mn Chlorophenyl 5tetrazole) ( 1methyl 2 methylthio 4pyrimidyl)monomethincyanine perchlorate. 2:4 Dimethylthiopyrimidine ( 0 34 g) and methyl toluene p sulphonate ( 0 37 g) were fused at 1400 for 1 hour 1 m Chlorophenyl 4: 5 dimethyltetrazolium iodide ( 0.67 g), pyridine ( 5 0 ml) and triethylamine ( 1.0 ml) were added and the mixture boiled under reflux for 1 hour The resulting yellow so 785,334 6 785,334

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* GB785335 (A)

Description: GB785335 (A) ? 1957-10-23

Improvements in determining the amount of solids in a slurry

Description of GB785335 (A)

COMPLETE SPECI!FItCATION Improvements' in Determining the Amount of Solids in a Slurry We, F. L. SMIDTH & CO. A/S, a Danish Company, of 77, Vigerslev Alle, Copenhagen Valby, Denmark, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to methods which are of general use in the handling of slurries but which are of particular use in the control of the operation of a continuous-flow thickener for slurry. Such a thickener is frequently used in technology as a means of reducing the water content in a continuously produced aqueous suspension. The result of proper treatment in the thickener is a thickened slurry from the bottom discharge of the thickener and an over- flow of almost pure water. As a typical example may be mentioned the use of a thickener for dewatering the raw slurry in the cement industry when the so-called flotation process is applied as a stage in the manufacture of cement. The flotation cells require a feed of raw slurry with a comparatively large water content, whereas the raw slurry cleaned by the flotation process should be fed to the cement-burning kiln, usually a rotary kiln, with a minimum water content so as to keep down the fuel requirements of the kiln, that is, the water content has to be so low as just to permit the slurry to be pumped through pipes. The importance of maintaining a low water content will be evident from the fact that an increase of 1% in the water content of the slurry is usually reckoned to involve an increase of about 2% in the fuel consumption. A thickener is therefore inserted between the flotation cells and the rotary kiln. For steady kiln operation it is important not only to maintain the water content as low as possible, but also as constant as possible, since, otherwise, there may be a risk of irregular passage of the material through the kiln. It is therefore of importance for the satisfactory operation of the thickener to maintain constant operating conditions to the greatest

possible extent. This is equally true of thickeners used for many other purposes. Endeavours to this end have hitherto consisted in checking the concentration of the dewatered slurry at regular intervals and taking care to ensure that the amount of slurry removed from the thickener is approximately equal to the amount of slurry fed to the thickener. Practical experience shows, however, that this is not enough. Occasionally, the concentration of dewatered slurry suddenly becomes very low and an investigation will then most often reveal that the thickener has become practically emptied of solids. At other times when the content of solids in the dewatered slurry is normal, the overflows may be turbid because the thickener has become filled with thick slurry. Thus, there is a need of a method by means of which the distribution of solids in a continuously operating thickener may be subjected to a very close control. In methods according to the present invention of determining the amount of solids in a slurry, liquid is supplied slowly to an open ended duct which passes downwards into the slurry, and the heights of the surfaces of the liquid within the duct and of the slurry outside the duct are measured. The liquid is conveniently the same as the liquid constituent of the slurry, which is usually water. In the operation of a continuous flow thickener according to the present invention, the amount of solids in the slurry in the thickener is determined this way, and thickened slurry is discharged from the thickener at a rate which is controlled in accordance with the amount determined. In particular, in making cement, dewatered raw cement slurry is fed from a continuousflow thickener to a cement burning kiln at a rate which is controlled in this way. The invention will be best understood by referring to the accompanying drawings in connection with the following description. In the drawings, Figure 1 is a sketch illustrating the principle of the method according to the invention; Figure 2 shows the apparatus which may advantageously be used for carrying through the method. Figure 3 shows how to provide remote indication of the measurements obtained by the method; and Figure 4 illustrates another way in which to provide remote indication. In Figure 1, a tank 1 contains a suspension 2 which will deposit a thickened slurry at the bottom after storing for a certain time. However, it must, in fact, be assumed that the tank is much larger

than appears from the Figure and that there is a constant feed of fresh suspension while simultaneously thickened slurry and almost pure water are being carried away. Under these circumstances an equilibrium will be established, but may be disturbed, and it is the object of the invention to prevent such disturbance. As previously mentioned the means to achieve this consists in passing a duct downwards into the slurry, and in Figure 1 numeral 3 denotes such a duct, which is simply a comparatively narrow pipe, open at both ends, and immersed vertically in the suspension to the level above which the content of solids is to be determined. A small amount of pure water is constantly fed to the upper mouth of the pipe through a cock 4. Since water is of a specific gravity (specific gravity 1) lower than that of the suspension above the lower opening of the pipe (average specific gravity d), the level of the liquid in the pipe will be somewhat higher than that of the suspension in the tank. The difference between the levels will be called ha when the pipe is lowered to a depth hb. Under these circumstances it is possible to establish the following equation: (ha+hb). l=hb.d, which, after conversion, may be written as ha ~=d1 hb One cubic meter of the suspension dranm from above the lower opening of the pipe will have an average weight of d metric tons. It will consist partly of solids assumed to have the specific gravity of D and to weigh T metric tons, and partly of water of the specific gravity 1. The following equation may then be made: T d. 1=T+(1--).1, D which, after conversion, may be written as: T=(d--l) . -- 1-1 D Inserting the value of (d- 1) found above, the result arrived at is: h, 1 T=. hb 1-1 D It will thus be evident that, provided the specific gravity D of the solids is known and that ha and hb are read, it is possible to express the weight in tons of the average content of solids in one cubic meter of the slurry located above the lower mouth of the pipe, which is just what is desired. If it is desired to know the weight of the total content of solids above the lower opening of the pipe, this result is

arrived at by multiplying by A. hb, which is the total volume of liquid above the lower opening of the pipe, A being the total horizontal cross-sectional area of the tank. With this multiplication the result is: ha.A Tt=T .A .hb=, 1-1 D Tt denoting the total content of solids. Figure 2 shows a practical apparatus. 1 denotes the tank containing the suspension 2 which is fed continuously through a pipe (not shown), and the thickened slurry is discharged through a central outlet (not shown). Along the bottom of the tank there may, for example, be provided a slowly rotating scraper for passing the thickened slurry to the outlet. The water separated off is discharged by an overflow which determines the level of the liquid in the tank. The pipe 3 shown may be supplemented by one, two or three further pipes having their lower openings at different levels from that shown so that the content of solids above the different levels may be examined by means of these pipes. Immediately below the level of the liquid surface the pipe 3 is crossed by a transverse pipe 5. Beneath the crossing the pipe 3 is provided with a valve 6, and similarly the transverse pipe 5 has a valve 7 in the part which opens freely below the liquid surface of the tank 1, while the opposite end of the pipe communicates with a vertical tank 8 which is open at its top. The freshwater feed cock 4 previously referred to is mounted above this tank. When this cock is open water will run into the tank 8 and raise the level in the tank and in the pipe 3 to equal heights ha above the surface of the liquid in the tank 1. Inside the tank 8 there is a float 9 attached to a bar 10 the upper end of which carries a pointer 11 moving over a fixed scale 12 from which ha may be read directly, the float 9 partaking of the variations of level of the liquid surface in the tank 8. The bar 10 is guided by a bush 13 connected with the lower end of the scale 12. In normal operation the valve 6 is open and the valve 7 is closed. For adjustment of zero the valve 6 is closed while the valve 7 is opened so as to provide direct communication between the tank 8 and the upper part of the tank 1. The water level in the tank 8 will then be made to correspond to the surface of the liquid in the tank 1 which indicates zero of measurement. Figure 3 shows how it is possible to provide remote indication of h,. In this case the pointer 11, instead of pointing at a scale 12, serves as sliding contact in a potentiometer 14 the ends of which are

connected with a storage battery 15. An electric indicator instrument 16 is connected with one pole of the battery and with the bush 13 which is electrically connected with the bar 10, but, as previously, permits the bar 10 to move freely. Under these circumstances the deflection of the pointer of the indicator instrument 16 will be proportional to h. Figure 4 illustrates another manner of providing remote indication. In this case there is no float and instead of an electric measuring instrument a pressure gauge 17 is used. The pressure gauge 17 communicates through a pipe 18 with the tank 8, the opening of the pressure gauge being on a level with the surface of the liquid in the tank 1. A small hand-operated pump 19 is provided by means of which air may be introduced into the pipe 18. When ha is to be determined, the pump is operated, and the pointer of the pressure gauge will then be deflected increasingly, but stop at a certain reading, and despite continued pumping it will not be possible to increase the deflection further, owing to the fact that the pressure inside the pipe 18 is now equal to the liquid pressure ha. The air pumped through the piping will then bubble up through the tank 8, and the deflection of the pressure gauge pointer will be proportional to ha. The part of the pipe 3 above the transverse pipe 5 is not essential, but facilitates cleaning of the apparatus and also ensures freedom from air bubbles which would falsify the readings. What we claim is: - 1. A method of operating a continuous-flow thickener for slurry in which the amount of solids in the slurry in the thickener is determined by supplying liquid slowly to an open ended duct which passes downwards into the slurry and measuring the heights of the surfaces of the liquid within the duct and of the slurry outside the duct, and in order to keep that amount constant thickened slurry is discharged from the thickener at a rate which is controlled in accordance with the amount determined. 2. A method of making cement in which the amount of solids in dewatered raw cement slurry in a continuous-flow thickener is determined by supplying liquid slowly to an openended duct which passes downwards into the slurry and measuring the heights of the surfaces of the liquid within the duct and of the slurry outside the duct, and in order to keep that amount constant the slurry is fed from the thickener to a cement-burning kiln at a rate which is controlled in accordance with the amount determined. 3. A method according to claim 1 or claim 2 in which the amounts of solid above two or more different levels in the slurry are determined by the use of two or more ducts which pass downwards into the slurry to these different levels.

4. Apparatus comprising a container for slurry, an open-ended duct which passes downwards into the slurry, means for supplying liquid slowly to the duct, and a device responsive to the height of the surface of the liquid in the duct.

* GB785336 (A)

Description: GB785336 (A) ? 1957-10-23

Method of preventing the cracking of continuous-cast bars of aluminium-basealloys

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PATENT SPECIFICATION 7859336 Date of Application and filing Complete Specification May 27, 1955. No 15443/55. Application made in Germany on June 15, 1954. Complete Specification Published Oct 23, 1957. Index at Acceptance:-Class 82 ( 1), A 8 (A 1: A 2: D: K: W: Z 3: Z 4), A 12. International Classification: -C 22 c. COMPLETE SPECIFICATION Method of Preventing the Cracking of Continuous-Cast Bars of Aluminium-Base Alloys W e, VER Em IGTE A Lr MIN Ix UM-WER 1 KE Aiz Ii F NGESEILSCIIAFT, a body corporate organised under the Laws of Germany, of Am Nordbahnhof, Boan-on-the-Rhine, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be

particularly described in and by the following statement: - This invention relates to a method of preventing the cracking of continuouscast bars of aluminium-base alloys which are free from intentional additions of iron IS and/or hickel. Round and flat bars used as starting material in the light metal semi-finished product industry are today produced almost exclusively by the so-called " water casting process ", that is to say a continuous casting process with short chill and direct water coolihg of the bar leaving the chill downwardly The method is economical and the bars produced in accordance therewith are particularly dense and fine-grained. Certain difficulties occur only with alloys which obtain stress cracks in the abrupt quenching peculiar to the method. These materials include, for example, the high-strength alloys of the class Al-ZnMg-Cu Stress cracks, can, however, also form with medium-strength alloys for example those of the class Al-Mg-Si The tendency to form stress cracks is combatted by special construction of the casting mould and of the metal feeding devices a.id also by adhering to special casting conditions Although these steps are successful, they are nevertheless occasionally complicated and reduce the casting output. It has now been ascertained, in accordance with the present invention, that the tendency of such aluminium base alloys to crack during continuous casting and parlPrce 3 s 6 d l ticularly during water casting, is considerably reduced by incorporating therewith between 0 01 and O 03 % of titanium. A further improvement is obtained by additionally incorporating with such alloys between 0 0025 and O 01 % of boron. In an Al-Zn-Mg-Cu, alloy, a titanium content of 0 03 % was found sufficient for the purpose of casting this alloy into 500 mm thick round bars, without the formation of anv cracks, and under casting conditions in which a third of the bars become cracked without the addition of titanium. The same result is obtained if 0 01 % of titanium and 0 003 % of boron is added to the melt This addition can be effected in the form of eleme-nts themselves or by means of salts, the amount of titanium added being calculated to be three or four times the amount of boron. EXAMPLE An Al-Zn-Mg-Cu alloy containing 1 7 % Cu, 2 8 % Mg, 5 7 % Zn, 0 2 % Cr, remainder Al was cast into round ingots of 350 mm diameter using a speed of '33 mm/min The casting temperature was 680 ' C The watercooled die was 140 mm higgh The first two ingots cracked when they reached the length of 750 mm Then 0.03 % Ti and 0 01 % B was added to the melt by means of an Al-Ti master alloy contaihing 5 % Ti

and an Al-B master alloy containing 10 % B After allowing the melt to stand for two hours, casting was continued under the conditions referred to above and no more cracking occurred.

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* GB785337 (A)

Description: GB785337 (A) ? 1957-10-23

Method of and apparatus for the continuous production of steel

Description of GB785337 (A)

PATENT SPECIFICATION 785,337 Date of Application and filing Complete Specification June I, 1955. No 15730/55. Application made in Germany on Feb II, 1955. Complete Specification Publislied Oct 23, 1957. Index at Acceptance:-Class 72, D 3 G( 2 A 1: 3: 4 A: 4 B: 7 G: 7 M), D 7. International Classification: -C 21 b. COMPLETE SPECIFICATION Method of and, Apparatus for the Continuous Production of Steel We, ROCHLINGSCHE E Is EN UND STARLWERKE GESELLSCHAFT MIT BESCHRANKTER HAFTUNG ZWEIGNIEDERLASSUNG MANNHEIM of 9, Richard Wagner Strasse, Mannheim, Germany, a Joint-Stock Company, organised under the Laws of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to a method of continuously producing steel

from pig iron, and to an apparatus for carrying out such method. All hitherto known methods for refining pig iron into steel required a very particular chemical composition of the iron Thus, a pig iron with a high silicon content required the use of the Bessemer process, that is, with an acid lining of the converter, while for refining pig iron with a high content of phosphorus the Thomas process requiring a basic lining had to be used Similarly, for applying the Siemens-Martin process, the lining also had to be adapted to the composition of the metal to be refined. For adapting the respective process to be applied to the composition of the pig iron, it is, however, also necessary that other factors be considered, for example, the length of time of the reaction as well as the temperature If the undesired impurities in the pig iron such as sulphur, silicon, phosphorus, manganese, or carbon should be substantially eliminated from a particular pig iron, great difficulties arise in all of the known processes due to the fact that the reactions for separating each individual impurity have to be carried out under entirely different conditions which are often quite opposed to each other Thus, for example, while very high temperatures are required for burning off the silicon, such temperatures are very undesirable for removing the phosphorus. The conditions are even worse if the refining process is to be carried out continuously. In the hitherto known continuous refining processes long extended containers were used lPrice 3 s 6 d l X De 'J wherein the different reactions were carried out side by side while the iron was flowing through the container It is self-evident that 50 the individual reactions of these processes which were supposed to lead to an elimination of the impurities had a yery detrimental effect upon each other It was therefore proposed to provide different parts of the long container 55 with different linings and to heat them to different temperatures However, these proposals did not result in a high-quality steel since a long extended container did not lend itself to be divided into different reaction 60 zones. It is one of the objects of the present invention to provide a new refining process and apparatus whereby the disadvantages of the prior processes and apparatus as outlined 65 above may be avoided in a very simple manner. Another object of the present invention is to provide a continuous method and apparatus for producing a steel of very high quality by carrying out the individual processes and 70 reactions so as not to affect each other. The principle feature of the present invention for attaining these objects resides in carrying out the various reactons one after the

other, rather than side by side as it was pre 75 viously done. To this end, the present invention provides a method for the production of steel in which the pig iron is refined in stages by causing the metal to pass successively through a plu 80 rality of reaction zones in each of which conditions are maintained to effect a desired step of refining characterised in that a charge of metal from an initial reaction chamber is delivered to the first reaction zone of a plu 85 rality of interconnected reaction zones the transference of metal from one reaction zone to the next of the interconnected zones being obtained by the flow of metal from beneath the surface of the metal bath in each said zone 90 whereby the delivery of slag or gases from one reaction zone to the next is prevented. The invention also provides an apparatus for carrying out the foregoing method which 785,337 comprises an initial reaction chamber having an outlet for the delivery of a charge of metal to the inlet of a reaction chamber forming the first of a plurality of reaction chambers arranged to provide a series of reaction zones in each of which a desired step in the refining of the metal is effected, said series of reaction zones being interconnected with one another so that the metal can be passed from one zone to another to effect in sequence the refining steps, and passages disposed below the level of metal in each reaction chamber so that metal may flow from one reaction chamber to the next in series, the chambers being otherwise isolated from one another during the refining operations. In the accompanying diagrammatic drawings, Figurie 1 is a cross section through an embodiment of the apparatus for carrying out the method according to the present invention taken along line C-C of Figure 2. Figure 2 is a cross section taken along lines A-A of Figure 1; and Figure 3 is a cross section taken along line B-B of Figure 1. Referring to the drawings, the apparatus consists of the initial reaction chamber I, and a series of interconnected reaction chambers II, Ill, IV, and V The initial chamber I is intended for eliminating the sulphur from the pig iron and is preferably mounted on rollers 1 so as to be tiltable Molten metal from a blast furnace is poured into this initial chamber, and soda or lime is then added The sulphurous slag may be removed through the drain 2 Any known means may be used to obtain an intimate mixture of the metal with the respective fluxes added thereto Thus, the chamber I may, for example, be designed in a known manner in the shape of an upright tube wherein the metal is charged into the upper part and the soda is added to the lower part so that the soda flows upwardly through the metal in a direction opposed to the direction of movement of the metal The chamber I may also be provided with an acid or basic lining.

By tilting the chamber I, the desulphurized metal is passed through the duct 3 to the first reaction chamber II, which is designed as a refiner, of the series of interconnected reaction chambers The chambet II is provided with an acid lining and a series of peripheral nozzles 4 By supplying oxidizing gases such as air, oxygen, or a mixture of both gases through the nozzles 4, it is possible to burn off the silicon contained in the metal very quickly together with some of the carbon This will increase the temperature to 17000 C K Inown cooling agents, such, for example, iron ore or scrap iron, may then be added through chutes so as to reduce the temperature to the desired degree. The desiliconized iron is next passed through the duct 6 into the reaction chamber III which is provided with a basic lining In this chamber the phosphorus will be burned off together with the remainder of the carbon, for which purpose an ample supply of addi 70 tions such as scrap iron, iron ore, or lime may be added through the chutes 7 to reduce the temperature to the degree most suitable for the removal of the phosphorus, that is, preferably to a temperature below 1500 C or 75 only slightly above the melting point of the metal Means may also be provided for controlling the supply of oxidizing gases passed through the nozzles 4. The primary object of such temperature 80 reduction, however, is to prevent absolutely the exceedingly dangerous over-refining of the melt which easily occurs in all the known refining processes. The reaction chambers II and III both pre 85 ferably have a circular cross section since such shape is most suitable from the standpoint of heat economy The reaction chamber III is made larger than chamber II since the reaction time required for removing the phos 90 phorus is longer than the time required for burning off the silicon in the chamber II. The nozzles are preferably fitted into each chamber II and III so that their inner ends will lie above the surface of the melt e g 5 95 mm above The effect of such arrangement is that the slag floating on the metal bath will not cool off but be heated by the hot gases issuing from these nozzle ends and will thus melt and remain fluid 100 In the chamber II not only the silicon but also the carbon is removed to a minor extent, while in chamber III the carbon is removed as well as the phosphorus to a major extent. The carbon monoxide liberated in both cham 105 bers may be combusted completely into carbon dioxide by means of compressed air which may be supplied from above through the nozzles 8 The application of compressed air has the further advantage that the heat 110 produced will be forced down upon the slag floating on the bath so that it will always be quickly reactive and fluid, and may be easily removed through the slag drains 9 and 10.

The hot waste gases may also be utilized 115 in a known manner for preheating the various additions and fluxes. The refined iron is then passed through the duct 11 into the chamber IV in which further metallurgical operations, especially deoxida 120 tion, may be carried out The required additions, for example, the deoxidising agents, may then be supplied through the chutes 12 The manner of supplying the proper amounts of the respective additions to the individual 125 chambers by means of a ram or slide 13 is illustrated in Figure 3 A similar arrangement may also be provided for feeding the respective additions to the chambers II and III so that the proper and most suitable 130 785,337 amounts thereof will be likewise assured at c these stages of the process t In the series of interconnected reactionx chambers II, III and IV, the ducts connecting adjacent chambers are positioned so that they are disposed beneath the surface of the metal. Thus the transference of metal from one chamber to the next is created by a flow from beneath the surface of the metal, and further each chamber is thus isolated from the next in the series. Since the refined iron passing from the chamber III into the chamber IV is at a lower temperature than required for the reaction chamber IV the latter is heated to the temperature required for the step in the process to be carried out in chamber IV The slag then forming, may be removed through the drain 15. From the reaction chamber IV the finished steel flows through the passage 16 to a storage tank or accumulator V from which the steel can be continuously or intermittently withdrawn For heating up its contents or maintaining the temperature thereof, the storage tank or accumulator V may likewise be equipped with burners 17, a slag outlet 18 and a steel outlet 19 Also, for adding alloying agents and for preheating the same, a suitable feeding device 20 as indicated in Figure 3 may be provided. The advantage of the method and apparatus according to the present invention not only consists in the fact that they permit the continuous production of steel of a predetermined nature and high quality but also in that any pig iron of any composition may be used as a starting material since the best possible conditions for eliminating each and any undesired impurity may be achieved without any difficulty. It is further of particular importance that the slag formed during each individual stage of the entire process may be discharged separately and can thus no longer produce any detrimental effect in the following stages This constitutes a particular advantage over all the refining processes previously known wherein the undesired impurities which had once been separated from the metal and were

contained in the slag which always participated in the reaction, were again passed back into the molten bath by the slag.

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