Abstract: A method is described for increasing the brightness of reductively bleached high yield pulps, comprising bleaching the pulps with a reductive bleaching solution under anaerobic conditions and maintaining the bleached pulps under anaerobic conditions during all handling steps subsequent to bleaching, including paper formation, wet pressing, and drying of the paper formed therefrom. The bleached paper has higher brightness than the same paper produced under aerobic conditions, and the bleaching and handling-derived portion of this higher brightness is retained after storage of the finished paper.

Abstract: Aqueous sodium dithionite slurries or suspensions, which are nonsettling during shipment thereof and are thereafter pumpable after storage at 32.degree.-40.degree. F. for at least fourteen days, comprise, on a weight basis, about 34% of sodium dithionite, about 0.17% of a xanthan gum, 5.5-6.5% of 50% sodium hydroxide, about 0.26% of a chelate, and about 1.96% of sodium tripolyphosphate which is added after adding the sodium dithionite. Preferably, the sodium tripolyphosphate is added last in making the slurry which is used as a woodpulp bleaching composition.

Abstract: A method is taught for increasing the yield of anhydrous sodium dithionite by adding an organic compound that is thiosulfate reactive to a batch reactor containing a puddle solution of methanol and fed with formic acid or an alkali formate as a first feed, an aqueous alkali compound as a second feed, an aqueous alkali formate solution as a third feed, and a methanolic SO.sub.2 solution as a fourth feed. This organic compound may be added prior to, combined with, or concurrently with one of the four feeds to the reactor. Preferably, it is added concurrently with the third feed and throughout the entire course of the reaction, ending with the beginning of the cooling period. A suitable addition rate is 0.4-0.6 wt. %/minute, preferably 0.5 wt. %/minute. All of the organic compound is consumed, and at least a portion of the thiosulfate ion is destroyed.

Abstract: This invention provides a process for improving the separation and recovery of metal formate and pentaerythritol as crystalline products, from an aqueous waste stream of a pentaerythritol manufacturing operation which involves the reaction of formaldehyde with acetaldehyde in the presence of a metal hydroxide catalyst.The pentaerythritol process waste stream is passed through a macroreticular resin bed to remove organic byproducts, and the purified waste stream is then evaporatively concentrated to produce crystalline sodium formate product. The resultant mother liquor is diluted with water-miscible alkanol to precipitate a pentaerythritol-metal formate mixture. The precipitate is washed with a portion of waste stream feed to dissolve the metal formate and yield undissolved crystalline pentaerythritol as a product.At least about 85 percent of the metal formate and at least about 90 percent of the pentaerythritol contained in the original waste stream are recovered as products of the process.

Abstract: This invention provides a process for preparing a novel class of isoxanthate salts, such as sodium S-benzylisoxanthate: ##STR1## The process involves a reaction between carbonyl sulfide and a metal mercaptide under aprotic conditions.This invention further provides a process for converting a metal mercaptide via an isoxanthate salt intermediate to a dithiocarbonate diester such as dimethyl dithiocarbonate: ##STR2## These compounds have found application as rust inhibitors, plasticizers, insecticides, herbicides and the like.

Abstract: Aqueous sodium dithionite slurries, which are non-settling during shipment thereof and are thereafter pumpable, and a method for their manufacture are provided. The slurries contain at least 25% by weight of crystalline pure sodium dithionite and at least about 0.13% by weight of a xanthan gum. As textile bleaching compositions, the slurries comprise, on a weight basis, at least about 36% of commercial sodium dithionite, at least about 3% of sodium hydroxide, at least about 0.25% of a chelate, and at least about 0.25% of a xanthan gum. As woodpulp bleaching compositions, the slurries comprise, on a weight basis, about 28% of commercial sodium dithionite, at least about 2% of sodium carbonate, at least about 2% of sodium tripolyphosphate, and at least about 0.13% of a xanthan gum.

Abstract: A process is disclosed for the preparation of 2,6-dihydroisopropylnaphthalene, dihydroperoxide involving the oxidation of 2,6-diisopropylnaphthalene in the presence of a catalyst wherein the improvement comprises carrying out said oxidation in the presence of a C.sub.5 -C.sub.14 aliphatic hydrocarbon solvent.

Abstract: A method is described for manufacturing, shipping, and handling a process component of heat-exchanging, air-conditioning, and refrigerating circuits, such as a filter drier or an accumulator, so that the process component can be joined to fluid tubing of such circuits by field brazing, using phosphorus-bearing copper filler metal with little or no silver content to make the braze joints. The method finally comprises the steps of selecting the tubing used for the connectors with a diameter which is smaller than the diameter needed for the field brazing to the circuit tubing and then mechanically expanding the other end of the tubing from 2% to 20% to this field brazing diameter, whereby the tubing is work-hardened to a hardness of 45-50 F Scale Rockwell and is able to withstand damage from shipping and handling operations and thereby returns the critical tolerances needed by the field brazing.

Abstract: A combined filter and filter-drier, for the suction side of refrigeration and air conditioning systems, comprises a dual filter system straddling a cylindrical plug of dessicant. Upstream of the dessicant, a rigidly built primary filter assembly comprises an inlet deflector and a stepped filter. Downstream of the dessicant, a secondary filter assembly comprises an outlet filter pad which is compressed by a coaxially disposed spring near the inlet of the filter/filter-drier. The inlet deflector is preferably triangular in shape and is disposed transversely to the inlet.

Abstract: An integral low-pressure accumulator/filter-drier for use in air conditioning and refrigeration systems between the evaporator and the compressor is described. This device is installed in upright position and includes a filter-drier and an accumulator which are separated by a bottom filter-drier retaining member which positions, in cooperation with a top filter-drier retaining member, an annular filter-drier assembly comprising a pair of thin cylindrical filter cartridges which straddle an annular dessicant bed which is itself straddled, at top and bottom, by a pair of annular filter pads. A pickup tube within the accumulator is sealably attached to an opening within the bottom retainer plate and extends coaxially within the inner filter cartridge, being biased against the top retainer plate by a spring assembly so that it is securely held and resistant to vibrations and rotation thereof.

Abstract: This invention provides a process for recovery of sodium formate from an aqueous waste stream which is a byproduct mother liquor derived from a reaction system in which pentaerythritol is produced by the reaction of formaldehyde with acetaldehyde in the presence of sodium hydroxide catalyst.As one of its important features, the invention process involves contacting the mother liquor with a monoalkylamine solvent which is highly selective for extraction of organic materials to the exclusion of sodium formate.

Abstract: A replaceable float oil separator, for installation in large refrigeration systems of the vapor compression type using refrigerant-immiscible lubrication oils, comprises a compact float assembly that is disposed transversely to the axis of its vessel and a removal assembly on the side of the vessel through which the float assembly can be removed for repair or replacement. The float assembly is compact in its design because a counterweight supports up to 90%, preferably 60%, of the weight of the float ball, in accordance with an energy balance equation. The removal assembly includes a flange cover, an o-ring, and a flange which is attached to the cylindrical side of the vessel, near its bottom where temperature cycling is minimal, whereby the vessel is semi-hermetically sealed. The float assembly is entirely supported by its oil return line which is attached to and passes through the flange cover of the removal assembly.

Abstract: A field test kit which uses a single vial is useful in testing acidity in refrigeration oils contaminated with a colored leak detector. This vial contains a pre-measured indicator solution and has sufficient additional volume that the test oil can be added directly to the indicator solution and accurately measured within the vial. After shaking, the mixture quickly separates into two phases. The color of the bottom phase indicates whether or not the acidity of the refrigeration oil exceeds 0.05 acid number.

Abstract: Substantially stable slurries containing 30-35% by weight of sodium dithionite are manufactured by evaporating sodium dithionite solutions while maintaining the heating medium at 220.degree.-250.degree. F. and the solution and slurry at 110.degree.-155.degree. F. under a vacuum of at least 25 inches Hg and by promptly cooling the resultant slurry while agitating it. The vacuum is preferably 26.5-27.5 in. Hg. At 4-5% by weight of the sodium dithionite and preferably at 4.3% by weight, NaOH is preferably added to the solution or alternatively to the slurry, immediately after evaporation. A chelator is preferably added to the solution to prevent metal contamination thereof. Zinc-derived sodiation liquor is the preferred sodium dithionite solution.

Abstract: This invention provides a process for recovery of sodium formate from an aqueous waste stream which is a byproduct mother liquor derived from a reaction system in which pentaerythritol is produced by the reaction of formaldehyde with acetaldehyde in the presence of metal hydroxide catalyst.Among its important features, the invention process involves evaporative crystallization of the mother liquor to separate out a major proportion of metal formate; dilution of the resultant secondary aqueous waste stream with methanol to precipitate metal formate/pentaerythritol solids; contact of the solids with a portion of the primary aqueous waste stream feed to dissolve metal formate; and recycle of the metal formate-enriched aqueous stream to the evaporative crystallization step of the process.

Abstract: A batch process, in which a sodium bisulfite compound is the alkaline agent, is described for producing anhydrous sodium dithionite at high productivity by reduction of sulfur dioxide with the formate radical in concentrated aqueous methanolic solution. Minimum amounts of water, in which sodium formate is dissolved, and of methanol, in which sulfur dioxide is dissolved, are used. The process provides the optimum productivity of U.S. Pat. No. 3,887,695 while obviating the hazards and freeze-up difficulties that are inherent in forming and transferring a sodium hydroxide solution at 160.degree. C. and also minimizes the amount of methyl formate formed at equilibrium after a large number of methanol recyclings.

Abstract: In a refrigerant system having a liquid trapping suction accumulator between the evaporator exit and the compressor entrance and a very short bore capillary as an expansion tube to replace the thermostatic expansion valve, a recirculating ejector is added to recirculate any liquid that may be trapped by the accumulator back into the evaporator inlet where it can be used to provide desired refrigerating effect without requiring additional work in the compressor. The expansion tube is positioned so that it functions as the primary nozzle of the ejector. Thus the high-pressure liquid refrigerant being expanded through the expansion tube becomes the prime mover that is needed to drive the liquid from the accumulator into the evaporator. Because the high-pressure liquid refrigerant must be expanded to the relatively lower evaporator pressure in any vapor cycle refrigeration system, the recirculating function is accomplished without using additional energy or penalizing system capacity.

Abstract: A filter-drier that provides two-way or bi-directional flow for a heat pump or other refrigeration system is described. This filter-drier contains a spring-loaded check valve at each end of an adsorption space containing an adsorbent such as activated alumina, molecular sieve silica gel or combination thereof. Each check valve is surrounded by a filter pad and a flexible diaphragm. Reverse-discharge and separate-discharge embodiments are particularly described.

Abstract: A device is provided for monitoring and controlling the above-ambient pressure in a system by comparing a net pressure force, produced by the system pressure on a pair of diaphragms having unequal areas, with a net spring force produced by a pair of opposed springs which clamp together a valve member and a valve seat in a pressure-relief member. The valve seat is connected by a passage to a port which is connected to the system pressure. While thus clamped together, the valve member and the pressure-relief member travel together through most of the total stroke created by movement of the pair of diaphragms and activate a microswitch for admitting additional fluid to the system when the system pressure is insufficient. If the net pressure force is sufficiently greater than the net spring force because of excessive system pressure, a port is opened when the valve strikes a stop and the pressure-relief member continues to move.

Abstract: A convenient batch process for producing anhydrous sodium dithionite at high productivity by reduction of sulfur dioxide with formate ion in aqueous methanolic solution is described in which sodium carbonate, in the form of a dry powder, is the source of alkali. Minimum amounts of water, in which sodium formate is dissolved, and of methanol, in which sulfur dioxide is dissolved, are used. In one aspect, SO.sub.2 -methanol solution, aqueous sodium formate solution, and powdered sodium carbonate are added to a methanol puddle solution, obtained from a preceding run which contains methyl formate in an equilibrium amount which is usually 4-8%, according to specific schedules which are proportioned to the rate of solution of sodium carbonate in the aqueous methanolic solvent and to the rates of reaction of sulfur dioxide with sodium carbonate and with sodium formate to form sodium metabisulfite.