Abstract: According to the invention the heating system for regenerative coke oven batteries that can be heated with rich gas and/or lean gas or mixed gas is provided comprising vertical flues cooperating in pairs, each vertical flue being connected to a regenerator for preheating the air and, in the case of lean gas operation, for preheating the lean gas or mixed gas. High and low combustion stages, as well as structure defining an internal flue gas return at levels above a flue base are provided. Discharge openings are provided at at least three levels for supplying each flue. A base discharge opening is provided at the flue base directly connected to regenerators. Hollow communicating channels are defined for connecting the regenerators to discharge openings located above the flue base. The hollow communicating channels are preferably formed in each communicating wall connected to a discharge opening leading only to one adjacent flue.

Abstract: A method for the preparation of 3,4-dihydro-alpha-pyrones by the thermolysis of 5-hydroxymethyl-gamma-butyrolactone in a liquid medium at temperatures between 300.degree. and 400.degree. C. and in the presence of aluminosilicates as catalysts is disclosed. The dihydropyrone that forms is distilled out of the reaction medium together with the reaction water immediately after its formation. Heat transfer oils, including, for example, polynuclear aromatic compounds joined together by methylene bridges or other bridge groupings, are especially suitable as heat transfer oils. The method has the advantage of permitting the temperature to be regulated within a definable range so that secondary reactions due to local overheating or imprecise temperature control occur to only a limited degree if at all.

Abstract: An agitator mill comprising a grinding vessel (3) which encloses a grinding area, a storage vessel (37) which contains grinding bodies (28), and a device (8) for feeding grinding bodies (28) from the storage vessel (37) into the grinding area. This device (8) essentially consists of a housing (11) attached to the grinding vessel (3) and a rotatable worm (13) situated therein. When the worm (13) is rotated, the grinding bodies (28) may be fed trouble-free as required into the grinding area, even if re-used grinding bodies (28) are concerned which have been worn out of true and have varied diameters.

Abstract: A process for the continuous production of an alkali metal alcoholate of a higher alcohol which comprises continuously introducing a higher alcohol into a reaction vessel, continuously introducing an alkali metal alcoholate of a lower alcohol into said reaction vessel and continuously and simultaneously distilling over and removing from said reaction vessel lower alcohol which forms.

Abstract: An aromatic polyazomethine of the structural formula ##STR1## wherein R represents hydrogen, halogen, alkyl or alkoxy,R' represents identical or different alkyl moieties which can be terminally halogen substituted or halogen or hydrogen,n and m represent values between 0 and 2, andx is equal to or less than 100.Also disclosed is a method for preparing such polyazomethine by contacting a benzidine compound of the formula ##STR2## wherein R and m have the meanings given above in an organic solvent with a dialdehyde of the formula ##STR3## wherein R' and n have the meanings given above. Preferably a solvent which forms an azeotrope with water is employed. The polyazomethines are useful as coloring materials e.g. pigments for polymers, especially thermoplastic polymers.

Abstract: A method and system for evaluating output signals from at least one sound pickup of a security alarm system and for generating an alarm signal by performing the following operations: before the system is placed into operation, determining a first signal frequency range containing the frequency of a signal to be determined and a second signal frequency range containing the frequency of an interference signal; then, during operation, filtering the two frequency range components out of the sound pickup output signals, each component containing a respective one of the frequency ranges, comparing the amplitudes of the two frequency components to one another and generating a difference signal representative of the difference therebetween, and generating an alarm signal whenever the difference signal traverses a threshold value.

Abstract: An aromatic bisazomethine prepared from the disubstituted benzidines and aromatic aldehydes, characterized by the general formula ##STR1## wherein each R=COOCH.sub.3, COOC.sub.2 H.sub.5, COOH, CH.sub.2 Cl, CHCl.sub.2, CH.sub.2 Br, CCl.sub.3, Cl or Br andeach R'=Cl, OCH.sub.3 or CH.sub.3.

Abstract: Oligomeric alkylene terephthalates having an average degree of condensation of 4 to 7 are produced by passing dimethylterephthalate and diol having at least 3 carbon atoms downwardly through a series of reaction chambers, each outfitted with stirring and heating means employed so that the temperature increases from stage to stage. Thereby transeterification is effected. The chambers are interconnected so that the methanol evolved in each chamber is vented without being admixed with the material undergoing transesterification in any of the other chambers. The transesterification product is then condensed at elevated temperature and under vacuum to produce the oligomer. The oligomers are high reactivity so that the further condensation thereof to polyesters is simplified.

Abstract: An improvement in the method of preparing a linear polycondensate of high molecular weight wherein a precondensate is initially formed and thereafter subjected to a one-step melt condensation in a vacuum while cleavage products are removed therefrom, the reaction mass being exposed in a thin layer by means of a stirrer to the reaction conditions, the improvement residing in employing as the precondensate a molten precondensate having an average condensation degree of at least 3, said precondensate being introduced into the melt condensation zone continuously while the cleavage products are driven off at the particular optimum, product-specific condensation temperature, the contents of the melt condensation zone being subjected to the action of a rotary stirrer until the melt has a melt viscosity of 1000 to 15000 poises and continuously withdrawing molten polycondensate in accordance with the speed of the reaction.

Abstract: Vinyl fluoride having an impurities content of less than 100 parts per million; a method of preparing vinyl fluoride with an impurities content of less than 100 parts per million which comprises contacting gaseous vinyl fluoride with a finely divided copper containing catalyst composition at a temperature of between 0.degree. and 100.degree. C.; a polyvinyl fluoride organosol having an organosol viscosity, determined in a 40 wt.% suspension in propylene carbonate of 20 to 100 cP; a method of producing a polyvinyl fluoride which when suspended in a suspension in polypropylene carbonate in an amount of 40 wt.% has an organosol viscosity of about 20 to 100 cP. which comprises heating vinyl fluoride in an aqueous medium containing a water soluble azo initiator at a pressure less than 140 kp./cm.sup.2 at a temperature of 60.degree.-85.degree. C.

Abstract: Polyvinylchloride inhibited against release of hydrogen chloride at elevated temperature is produced by polymerizing vinyl chloride in a reaction medium having finely divided calcium carbonate dispersed therein.