Liquid Blending

Mutually soluble liquids are blended to provide a desired degree of uniformity in an acceptable mixing time. An efficient mixer design is important for good product quality at a high production rate. The critical issues that need to be addressed include number of liquids and their volumes, tank configuration, batch mixing times or residence time distribution in a continuous system, and physical properties. 

Testing in the lab or pilot plant will help define the appropriate design and scale-up requirements. The reader is referred to Chapter 10 on solid-liquid mixing and Chapter 13 on reacting solids. 

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Ribbon blenders are essentially self-contained mixers. They are employed in a variety of solid-liquid, solid-solid, and liquid-liquid blending applications in the chemical process industries. Examples include plastics, pigments, pharmaceuticals, specialty chemicals, confectionary. 

Equivalent liquid motion (e.g., liquid blending where the liquid motion or corresponding velocities are approximately the same in both cases). 

Liquid blending, equivalent liquid motion, corresponding velocities are about equal. Similar results obtained with equal tip speed or torque per unit volume. 

Liquid-Liquid blending to a homogenous product Turbulent Flow 4-6... 

Rushton (R11) in 1954 presented a graph showing contacting efficiency as a function of impeller diameter at constant power input. He found that the rate of mass transfer between phases increased to a maximum and then decreased as the impeller diameter increased. The optimum occurred at a ratio of impeller to tank diameter of about 0.25, a ratio which is much smaller than that found for liquid blending. 

The main performance characteristics of light-duty liquids or dishwash blends are soil emulsification and foaming. Figueroa-Raulli [73] published a comparative study of AOS vs. alkyl sulfates (AS), alcohol ether sulfates (AES), and linear alkylbenzenesulfonates (LAS) in light-duty liquid blends. The blends were evaluated for flash foam, the stability of foam under accumulating soil loads, and for the number of plates washed. Blend performance is expressed as a percentage of a dishwash reference standard. 

LIQUID BLENDING PROBLEM OF RUSSELL AND DENN Liquid densities depend on concentration... 

Laminar premixed flames, 7 443 445 Laminar regime, viscous liquid blending in, 16 690-691... 

Mischmetal, 5 677-678, 681 Miscibility diagrams, 22 302 Miscible flooding, 12 23 Miscible liquids, blending of, 16 687-691, 705, 712-713... 

Slurries 1, 3, 4 and 8 show the new liquid blend, l,2-dibromo-2,4-dicyanobutane + 2-bromo-2-nitropropane-l,3-diol, as being the most effective product, while the 2-bromo-2-nitropropane-l,3-diol was most effective in slurries 2, 5, 6 and 7. In order to appreciate the advantages of this new blend over the products tested, the observations from the study of each of the products are listed in the discussion. 

This study was designed to evaluate the performance of commonly used biocides against the performance of a new liquid blend. In order to choose an effective preservative package, the two main criteria the biocide must have, are (i) to be approved by the US Food and Drug Administration (FDA) under sections 21 CFR 176.170 and 21 CFR 176.180 which cover components of paper and paperboard in contact with foods and (ii) to be designated as a safe biocide (low toxicity, non-sensitiser, easy to handle). The three most commonly used products (i) 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one, (ii) 1,5-pentanedial and (iii) l,2-benzisothiazolin-3-one, currently meet the above criteria. The new liquid blend, l,2-dibromo-2,4-dicyanobutane -I- 2-bro-mo-2-nitropropane-l,3-diol was also designed to meet the criteria. 

The new liquid blend, l,2-dibromo-2,4-dicyanobutane -1- 2-bromo-2-nitrop-ropane-l,3-diol, was very effective in controlling the Methylobacterium sp. It is the recommended product of choice for the preservation of pigmented slurries. 

Liquid flavours can be divided into low-viscous liquids, medium-viscous liquids, emulsions, pastes and suspensions. The main processing of liquid flavour production is basically liquid blending. The most popular carriers for flavours for aqueous systems are ethanol, propylene glycol or glycerol. For fat-soluble flavours, triacetin or vegetable oils are the most important carriers. 

A revolving propeller traces out a helix in the fluid. One full revolution moves the liquid a fixed distance. The ratio of this distance to the propeller diameter is known as the pitch. In the case of turbines, pitch is the angle the blades make with the horizontal plane. Propellers are members of the axial class of impeller agitators. The propeller is turned so that it produces a flow toward the bottom of the vessel. Propellers are more frequently used for liquid blending operations than for mass transfer pmposes (Treybal, 1980). 

Nonflammable indicates that no flash point was observed by the ASTM test method D-3278-82 or D-56 below the boiling point of the solvent mixture or below 100°F, whichever is lower (this is the DOT, ANSI, and NFPA definition). The composition of liquid blends can vary from the originally supplied composition during use, owing to tile differing vapor pressures of the individual constituents. Care must be taken to avoid preferential loss of PFCs, which would result in flammable mixtures. 

The stability of the emulsions further permits them to be compounded in simple liquid-blending vessels by means of agitators, eg, marine-type propellers, paddles, or turbines. The adhesives can be adapted to any type of machine application, ie, from spray guns to rollers to extruder-type devices. Different applicators are fairly specific in their viscosity requirements, as are the various substrates receiving the adhesive. 

For adhesive systems, the liquid epoxy resins most widely used with LP-3 polymers are liquid unmodified and diluent-modified bisphenol A resins and liquid blends of bisphenol A and bisphenol F resins. Solid bisphenol A, multifunctional, and aliphatic diepoxy resins have also been used. Ratios of liquid polysulfide polymer to epoxy are in the range of 1 2 to 2 1. The effect of various degrees of polysulfide on cure properties of a DGEB A epoxy is shown in Table 7.7. An increase in elongation and impact strength is the result of increased amounts of the liquid polysulfide polymer. 

Nonionic/Anionic/Liquid Blended processing aid for wool. 

The ultimate consistency attainable depends on the fats and oils in the formulation, the processes to which these have been subjected, the equipment and conditions used to solidify them, and the conditions under which these products are stored prior to utilization. Properly formulated liquid blends can be converted to tme plastic solids only when the apparatus employed provides controlled cooling, crystallization, and working techniques. The manner in which these plasticity and crystallization theories have been applied and employed in practice can be discerned by examining commercial production apparatus. 

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