MXPA97001622A

MXPA97001622A - Mixing apparatus with cutting effort and use of delmi

Info

Publication number: MXPA97001622A
Application number: MXPA/A/1997/001622A
Authority: MX
Inventors: Page Shirtum Robert
Original assignee: Gillis Paul A; Page Shirtum Robert; The Dow Chemical Company; Tirtowidjojo Cheryl A; Trent David L
Priority date: 1995-10-12
Filing date: 1996-10-10
Publication date: 1999-02-24

Abstract

Mixing apparatuses with shear stress and associated methods are described for controllably and inexpensively producing small gas bubbles, for example, of an average diameter of less than about 0.5 millimeters in a liquid, by which the mass transfer of the gas in the gas is improved. the liquid (compared to mass transfer achieved by conventional large bubble generators under the same circumstances) in applications that benefit from this improved mass transfer, which involves injecting a gas under pressure via one or more orifices into a liquid that is flowing at a sufficient speed to make the bubbles formed in the hole (holes) subdivide to the small bubble size you want

Description

# MIXING APPARATUS WITH CUTTING EFFORT AND USE OF THE SAME This invention relates in general to a mixing apparatus with shear stress and its use in various processes. This invention relates more particularly to a mixing apparatus with shearing force which generates very small bubbles and with the use of the apparatus for supplying a gas to a liquid medium. This invention relates still further to "FF 10" particularly with this apparatus and its use to increase the mass transfer of a reactive gas in applications such as a chemical or biological reaction One of these reactive gases is oxygen Motarj emi and GJ Jameson , in "Mass Transfer from Very Small Bubbles - The Optimum Bubble Size for Aeration ", Chemical Engineering Science, Volume 33, pages 1415-1423 (1978), shows that bubbles are frequently used for the purpose of mass transfer, especially in systems in which oxygen dissolves in water. Suggest, on the page 1422, a need to develop new practical ways to make "very small bubbles, less than 1 millimeter in diameter, in large quantities." G.J. Jameson, in "Bubbles in Motion ", Trans IChemE, Vol. 71, Part A, pages 587-594 (November 1993), provides a global view of the contributions of Professor John Davidson to the study of bubbles and flows of two gas-liquid phases. On page 592, he discusses problems inherent in generating small bubbles by reducing the diameter of the middle orifice of the diffuser. The problems include notable increases in the pressure drop through the diffuser and potential blockage of the orifice by the solids present in water bodies as in drains. On page 593, discuss the coalescence of the bubbles and note that it will be necessary to impart a force to the bubbles in order to remove them quickly from the hole to avoid the v-H coalescence. The possible means of imparting this force include a cross flow of fluid through the orifice or an oscillation applied to either the same orifice or gas within the orifice. In a first aspect, the present invention provides a mixing apparatus with shear stress which is capable of generating bubbles that are less than 1 millimeter in diameter without incurring at the same time the problems mentioned by Jameson with respect to reducing the diameter of the middle orifice of the diffuser in a conventional bubble-generating apparatus, the apparatus of the present invention. invention comprises: at least one conduit for transporting a first fluid to be mixed, which is open at its first end to receive the first fluid to be mixed and a second end closed, with one or more openings defined in Each of these conduits close to the second closed end * thereof, through which a fluid received at the first open end leaves the conduit; a mixing body generally defined around the conduit or conduits and having a first closed end 5 defining a corresponding opening or openings therein through which the respective conduit or conduits pass, the mixing body further having a second end defining a orifice restricted with each of these ducts and with respect to a hollow space enclosed by the mixing body 10 and defined between the first closed end and the second end of the mixing body, the openings being placed in each of the ducts substantially in the restricted orifice associated with a given conduit; and a second fluid supply conduit in fluid communication with the hollow space enclosed by the mixing body, to provide a second fluid thereto which passes through the one or more restricted orifices in the second "end" of the mixing body and which mixes in a cutting manner with the first fluid supplied from the openings placed in the respective restricted orifice A second aspect of the present invention relates to a mixing apparatus with shear stress comprising: one or more conduits to provide a first 25 fluid to be mixed, with each of the conduits defining one or more openings therein over a length of the respective conduit; a mixing body having a first end and a second end and defining between its first and second ends a generally enclosed hollow space with which a fluid supply conduit is in fluid communication, with the first and second ends of the mixing body each having defined therein a corresponding respective opening for receiving a conduit carrying the opening therethrough so that the openings in the conduit provide the first fluid to be mixed are placed in fluid communication with the hollow space. A third aspect of the present invention relates to a third related embodiment of a shear mixing apparatus, comprising a hollow sub-assembly receiving gas and liquid, a bubble-generating sub-assembly and, optionally, a handle, the subassembly being received the gas and liquid operatively connected with, and in fluid communication with, the bubble generator subassembly. The subassembly receiving gas and liquid for this third embodiment desirably comprises: a central conduit having an open inlet end for receiving a liquid therein and an outlet end in fluid communication with the sub-assembly that generates bubbles; and a housing receiving gas that is generally disposed near and separates from the central conduit so as to define a passage for the flow of a gas therethrough to the sub-assembly that generates bubbles, and which includes at least one passage that receives gas to receive a gas through it and communicate it via the passage to the subassembly that generates bubbles, the housing that receives gas being attached to one of its ends in a narrow gas relation with the central duct at the closest point to the entrance end of the central conduit to its outlet end. The subassembly that generates bubbles in the third apparatus that mixes with shear stress desirably comprises a base plate that is attached to the central conduit adjacent to its outlet end and in a narrow gas relationship, a gas and liquid distribution housing for containing and distributing the gas and liquid received from the gas receiving housing and the central conduit, respectively, and which is attached to the base plate in a narrow gas relationship, and a cover plate which in turn is attached to the housing of the gas. distribution of gas and liquid in a narrow gas relation, the gas and liquid distribution housing having a central, funnel-shaped, fluid expansion housing that divides the sub-assembly and the bubble generator with the base and deck plates in an upper chamber, of liquid expansion, and a lower chamber, of gas expansion, the funnel-shaped fluid expansion housing having a hollow rod which fits in a gas tight seal on a portion of the central duct near the outlet end of the central duct and a peripheral extension projecting outwardly from the hollow stem that has defined therein a plurality of openings that they are in fluid communication with the gas expansion chamber and a plurality of fluid channels that are in fluid communication with the liquid expansion chamber, the openings being in fluid communication with the fluid channels for mixing the gas and the liquid transported through them. Fluid channels are preferably separated from each other by fluid diverters that are also defined in the peripheral extension projecting outwardly from the hollow rod. A fourth aspect of the invention relates to a method of generating gas bubbles in a liquid having an average diameter of less than about 0.5 millimeters and especially less than about 1.0 millimeters, the method comprising: a. place a gas under a pressure that is sufficient to form gas bubbles when the gas is introduced into a liquid by means of at least one opening in a member or element that separates the gas and the liquid; and b. flow the liquid past the opening at a flow rate selected to provide a number of Weber exceeding a critical Weber number for gas and liquid in order to achieve a desired bubble diameter. Figure 1 is an axial schematic sectional view of a shearing mixing apparatus of this invention, in a first embodiment and according to the first embodiment. * 10 aspect mentioned above. Figure 2 is an axial schematic sectional view of another shear mixing apparatus of this invention, as characterized by the second aspect mentioned above. Figure 3 is an axial schematic sectional view of a third embodiment of a shear mixing apparatus of this invention. Figure 4 is a top plan view of the apparatus of Figure 3. Figure 5 is a graphical representation of the data presented in Table I. Table I is a compilation of oxygen transfer test results for Example 2. The vertical axis represents La20 and the horizontal axis represents gas costs in liters per standard minute (SLM). Figure 6 is a graphic illustration of the pressure drop * of energy expended (in kilopascals) to achieve a given bubble diameter using conventional shear mixing technology. Referring now to the drawings, Figures 5 1, 2 and 3 provide schematic views of three related apparatus that are representative of the present invention. Figure 4 is another view of the apparatus shown in Figure 3. The different apparatuses are not drawn to scale and characteristics such as size, location and number of openings are illustrative rather than limiting - Figure 1 depicts a mixing apparatus with shear stress generally designated by reference numeral 10. The apparatus 10 comprises a hollow mixing body 11, a conduit 15 for transporting a first fluid that is to be mixed, a second supplied conduit of fluid 20 containing the passage 21 and a plug 25. The mixing body 11 has a first end 12 and a second end 13 that is far from the first end 12. The mixing body 11 keeps a hollow space 30 between your first and second ends 12 and 13. The second end 13 has an opening defined therein 14. A convenient shape for the body of the mixer 11 (ignoring the second fluid supply conduit 20 for visualization purposes) is a straight circular cylinder hollow that is open in a End (second end 13) and closed, except for an opening 1 at one end (first end 12) opposing the open end. When the mixing body has that shape and there is only one duct 15, the opening 14 and the duct 15 are desirably coaxial with the axis of the mixing body.

When there are at least two conduits 15, the number of openings 14 increases to coincide with the number of conduits 15. The plug 25 fits within the mixing body 11 near its second end 13. The plug 25, when * 10 has desirably defined therein at least one opening or orifice 26. The opening 26 is desirably arranged so that it is coaxial with the axis of the mixing body when there is only one conduit 15. When there are at least two conduits 15, each opening 26 is preferably coaxial with a corresponding conduit 15. The conduit 15 has a first end 16 and a second end 17 that is distant to the first end 16. The first end 16 is open and preferably is connected to a source of a first driving fluid (which is not HE sample). The second end 17 is closed or capped to prevent the first drive fluid from flowing via that end. The conduit 15 passes through, and is fitted within the opening 14 of the first end 12 of the mixing body 11. The adjustment of the conduit 15 within the opening 14 'preferably is carried out in a manner that provides a seal * substantially leak-proof, preferably gas-tight, around the conduit 15 where it passes through the opening 14. The conduit 15 also passes through the opening 26 of the plug 25. In doing so, the conduit 15 and the plug 25 combine to form a restricted hole 27 in relation to hollow space 30, in the form of a longitudinal annular space defined along a length of conduit 15 at a location near the second end 17. Within that length, conduit 15 has defined therein a * 10 plurality of openings 19. Each opening 19 is in fluid communication with the restricted orifice 27. The number, size, spacing and location of the openings 19 is sufficient to provide small bubbles when operated in accordance with the fourth aspect of the invention. present invention. The second supplied fluid conduit 20 is pre-connected to the mixing body 11 at the intermediate point between the first end 12 and the second end 13 of the mixing body 11. When so connected, the passage 21 of the second conduit 20 is in fluid communication with the Hollow space 30. If desired, one or more additional fluid supply conduits can be operatively connected to the mixing body 11 in a similar manner to provide additional fluids (gases or liquids, but preferably liquids) to the mixing body 11 to be combined with a gas (which can be a single gas or mixture of individual gases) or a plurality of gases from a duct 15 or ducts 15. Turning now to Figure 2, a mixing apparatus with cutting force according to the second aspect of the invention, and generally designated by reference numeral 40. The apparatus 40 comprises a hollow mixing body 41, a conduit carrying an opening 50, and a supply conduit 60 containing the passage 61. The mixing body 41 has a first end 42 and a second end 43 that is far from the first end 42. The The mixing body 41 contains a hollow space 55 between its first and second ends 42 and 43. The first end 42 has defined therein an opening 44. The second end 43 has defined therein an opening 45. Each opening 44 is preferably coaxial with an opposite opening 45. One way suitable for the mixing body 41 (ignoring the fluid supply conduit 60 for display purposes) is a hollow straight circular cylinder that is closed on both sides except for the openings 44 and 45. When the mixing body has this shape, each conduit 50 is preferably aligned so as to be coaxial with the axes of a pair of opposed openings 44 and 45. The duct 50 has a first end 51 and a second end 52 that is distant from the first end 51. The duct 50 passes through, and is adjusted within the openings 44 and 45 of the mixing body 41. The fitting of the duct 50 within the openings 44 and 45 is preferably carried out in a manner to provide a leak-tight seal, preferably gas-tight around the duct 50 where it passes to through the openings 44 and 45. Because the first end 42 and the second end 43 are separated from each other, the mixing body 41 encloses a length of the conduit 50 through it. In this length, the conduit 50 has defined in the same a plurality of openings 54. Each opening 54 is in fluid communication with the space hollow 55. The number, size, spacing and location of the openings 19 is sufficient to provide small bubbles when operated in accordance with the fourth aspect of the present invention. The fluid supply conduit 60 is operatively connected to the mixing body 41 at the intermediate point between the first end 42 and the second end 43 of the mixing body ll. When connected in this way, the passage Si of the conduit 60 is in fluid communication with the hollow space 55. If desired, one or more additional conduits of The fluid supply may be operatively connected to the mixing body 11 in a similar manner, to supply additional fluids to the mixing body 11. A first driving fluid under pressure, desirably a gas such as air or oxygen, flows from a source (no. shown) towards the duct 15 of the apparatus 10 (shown in Figure 1) by means of an operative connection with the first end 16 of the first duct 15. The first driving fluid, necessarily, enters the restricted orifice 27 via the openings 19 in the conduit 15. A second driving fluid, desirably a liquid such as water or brine, flows from a source (not shown) into the passage 21 by means of an operative connection with the second fluid supply conduit 20. The second driving fluid flows from the passage 21 to the hollow space 30. When the hollow space 30 is filled with the second driving fluid, the fluid flows to and through the restricted orifice 27. The restricted orifice 27 has a cross-sectional area which is smaller than that of the hollow space 30, so that the second driving fluid has a velocity through the orifice 27 which is greater than its velocity through the passage 21 the hollow space 30. The first The motor fluid flowing through the openings 19 is under sufficient pressure to prevent the second driving fluid from entering the conduit 15 through the openings 19. The pressure is also sufficient. to generate gas bubbles when the first driving fluid is a gas and the second driving fluid is a liquid. It is believed that the flow of the second driving fluid through the orifice 27 is strong enough to overcome the interfacial tension between the gas and the liquid thereby forcing the bubbles to break into smaller bubbles. If both motor fluids are gases or liquids, the apparatus 10 is believed to facilitate the mixing of the motor fluids. If the second driving fluid is a liquid and the first driving fluid is a gas that is miscible in the liquid, the apparatus 10 is believed to promote the dispersion of the miscible gas through the liquid. The apparatus 40 shown in Figure 2 conveniently combines a first drive fluid, desirably a liquid, which flows through the passage 61 of the fluid supply conduit 60. The gases and liquids specified with respect to the apparatus 10 also work for the apparatus 40. The first drive fluid flows from a source (not shown) into the conduit 50 in the manner of an operative connection with the first end 51 of the conduit 50. Without change in the cross-sectional area, there is substantially no variation in the expense of the fluid as the drive fluid flows through the conduit 50. The second drive fluid flows into the passage 61 from a source (not shown) by means of an operative connection with the fluid supply conduit 60. The second flow fluid flows from the the passage 61 towards the hollow space 55 and, from there, via the openings 54 towards the duct 50. The second driving fluid is under sufficient pressure to generate bubbles and sust It prevents the entry of the first driving fluid into the hollow space 55. As with the apparatus 10, the flow of a liquid driving fluid is desirably sufficient to cause subdivision of F the bubbles generated when the gaseous drive fluid passes through the openings and towards contact with the liquid driving fluid. In addition, the apparatus 40 is convenient for the same purposes as the apparatus 10. FIG. 3 still represents a third related embodiment of a shear mixing apparatus of the present invention, which is generally designated by the reference numeral 100. The apparatus 100 comprises a hollow sub-assembly that receives gas and liquid 110, a subassembly that generates bubbles 140 and an optional handle 190. Handle 190, when present, facilitates the installation of apparatus 100 in a container (not shown) such as a polymerization reactor or a bioreactor. The receiver subassembly 110 comprises a conduit central 111 and a gas receiving housing 120. The central conduit 111 has an open inlet end 112 and a H- exit end 113 that is distant from the first end 112, and in fluid communication with the bubble generator sub-assembly 140. The central conduit 111 has defined therein axial passage 114 which is convenient for transporting liquids. The gas receiving housing 120 may preferably be composed of a single structural element, or as shown in Figure 3 may comprise an annular gas receiving chamber housing 121 and a annular gas transport housing 123. The gas receiver chamber housing 121 has defined therein at least one gas receiver passage 122. The passage 122 desirably has internally screw thread to facilitate a gas tight connection with a source of gas (not shown). The gas receiving chamber housing 121 encloses a hollow chamber 124 which is in fluid communication with the gas receiving passage 122. The annular gas transport housing 123 desirably functions in combination with at least a linear portion of the central conduit 111. to form an elongated annular space 126 for communicating gas from the gas receiving chamber housing 121 to the sub assembly that generates bubbles 140. The housing 123 has a first end 125 inserted in the hollow chamber 124 and a second end 127 that is remote from the first end 125. The housing 123 preferably externally has screw thread near its second end 127. The annular space 126 is also in fluid communication with the chamber 124 so that a first drive fluid (preferably a gas) entering the passage 122 can flow into the hollow chamber 124 and then through the annular space 126. The components of the subassembly re ceptor 110 are operatively connected to one another by means of suitable fastening elements such as fillet welds 115. The bubble generating subassembly 140 comprises a base plate 141, gas and liquid distribution housing 150 and cover plate 180. The base plate 141 has a plurality of apertures 142 defined therein. The base plate 141 also has an annular sealing ring housing 145 therein which conveniently contains sealing elements 146. The sealing elements 146, conveniently a 0-shaped ring. , works to provide a generally gas-tight seal between the base plate 141 and the housing 150. The base plate 141 preferably also has a central or axial opening 149 defined therein. The opening 149 preferably has internally screw thread so that the end 127 of the housing 123 can be screwed into the opening 149 when the subassembly 140 and the receiver subassembly are assembled as shown in Figure 3. The distribution housing 150 comprises, in operative combination, the outer wall 151 and the central fluid housing 160. The housing 160 desirably has the shape of a funnel (FIG. an implement that is commonly composed of a truncated conical hollow element with a hollow tube or rod extending from the smaller end of the element) with a hollow rod 170 and an outwardly projecting extension 161 from the rod 170 to the cover plate 180. The extension 161 preferably extends outward from where it is operatively connected, # preferably by a continuous fillet weld or by other satisfactory joining means, with the outer wall 151. The hollow rod 170 is defined in the same an inner annular space 171. The annular space 171 conveniently contains a sealing element 172, conveniently a 0-shaped ring, to provide a gas-tight and fluid-tight seal when the rod 170 slidably fits on a linear segment of the central duct 111 near the second end 113 of the conduit 111. The outwardly projecting peripheral extension 161 has therein defined a plurality of openings 162. The extension 161 also has defined therein a plurality of fluid channels 163. Each fluid channel 163 is separated from the adjacent fluid channels 163 by fluid diverters 164 (shown in Figure 4). The extension 161 further has therein defined a plurality of openings 165. The openings 165 desirably pass through fluid diverters 164 (see Figure 4) and, have preferably internally screw thread. The operational combination of the outer wall 151 and the central fluid expansion housing 160 encloses a hollow space 143. The hollow space 143 is in fluid combination with openings 162 and, when the apparatus 100 is assembled as shown in Figure 3, the annular space W 126 is lengthened. The outer wall 151 desirably terminates in a flange "152. The flange 152 is spaced apart from the outwardly projecting peripheral extension 161. The flange 152 has defined therein a plurality of openings 154. The openings 154 preferably have internally screw threads and are aligned with the corresponding openings. 142 on the base plate 141. The outer wall 151 is ff operatively connected to the base plate 141 by convenient fasteners such as head screws 144. The cover plate 180 has defined therein a plurality of openings 181. The openings 181 t desirably are axially aligned with openings with screw thread internally 165 on the outer edge 161. The cover plate is desirably secured to the dispensing housing 150 by fasteners 183 as head screws which are operatively connected by means of the openings 181 and 165. The cover plate 180 desirably has defined therein an axial center fluid diverter 185. The diverter 185 desirably has the shape of a cone with an apex projecting toward, and in axial alignment with, the axis of the central conduit III when the apparatus 100 it is assembled as shown in Figure 3. The cover plate 180 and the central fluid expansion housing 160, when assembled, define a hollow fluid distribution space 158. The cover plate 180 and the expansion housing 160 also contain fluid channels 163. The dispensing space 158 is in fluid communication with the fluid channels 163 and the central conduit 111 when the apparatus 100 is assembled as shown in Figure 3. When the handle is to be employed 190, the cover plate 180 also has the central aperture 188 defined therein. The aperture 188 desirably has internally screw threads to accommodate a handle externally with Screw thread for ease of installation. Figure 4 shows a top plane view of the distribution housing 150. The openings 162 are shown in alignment with the fluid channels 163. The fluid channels 163 are separated by fluid diverters 164, conveniently in the form of saw teeth. The apparatus 100 carries a second driving fluid (preferably a liquid) from a source (not shown) through the central conduit III to the distribution space 158 and then to the fluid channels 163.

Simultaneously, the apparatus 100 transports a first drive fluid (preferably a gas) from a source (not shown) through the passage 122, the chamber 124, the annular passage 126 and into the chamber 143 from which it exits via the openings 162. The motor fluids and the equipment described for the apparatuses 10 and 40 apply equally well to the apparatus 100. The speeds of the motor fluids or linear costs (as opposed to the volumetric ones) are preferably selected together with an apparatus, the apparatus 10, apparatus 40, apparatus 100 or a variation of any of them, in order to reach a Weber number that exceeds a critical Weber number for a diameter or bubble size desired for the gaseous and liquid motor fluids they enter the apparatus, as will be better explained later. Expert technicians can choose a suitable apparatus and determine satisfactory operating conditions without undue experimentation. The skilled artisans may also determine suitable modifications of any apparatus described herein without undue experimentation or exceeding the spirit and scope of the present invention. The apparatus within the scope of the present invention, as represented in Figures 1, 2 and 3, are useful in a variety of applications. Illustratively, non-limiting uses include improving the transfer of masses of oxygen or air in the water used in bioreactors that treat waste water streams, improving the performance of oxygen activated polymerization inhibitors in one or more stages of a reaction of polymerization and generally, improving the miscibility of at least one gas in a liquid. An example of a commercially significant use of the mixing apparatus of the present invention in the latter aspect would be the production of polycarbonates in a solution process or in an interfacial process in particular, wherein a gaseous carbonic acid derivative such as phosgene is reacted with a dihydroxy compound such as the aromatic dihydroxy compound 2, 2-bis (4-hydroxyphenyl) propane (commonly, "Bisphenol-A") in a homogeneous solution containing Bisphenol-A and phosgene (the solution process), or in a two-phase system where the Bisphenol-A is dissolved or suspended in an aqueous solution of an organic base and an organic solvent is also present (Methylene chloride, for example) which is capable of dissolving the polycarbonate oligomer product of the reaction of phosgene and Bisphenol-A (the interfacial process). Various batch and continuous processes and unit operation configurations, involving both the flow-cap and the continuous agitation tank reactors, have been described in the art or are known, see, for example, United States Patent Number : 4,737,573 and 4,939,230 and the different references cited therein. Those skilled in the art of polycarbonate will appreciate that the shear mixing apparatus of the present invention can be used suitably and desirable in many of these processes to improve the flow rates established therein, and with respect to interfacial processes. known in which the phosgene is bubbled in the process with the organic solvent methylene chloride, for example, will beneficially improve the dispersion of the phosgene in the methylene chloride. In another general aspect, it will be apparent to those skilled in the art that the present invention both in its aspects of apparatuses and methods is useful in reducing the reaction time, and thus in reducing either the number or size of the reaction vessels required. to produce a predetermined amount of a product (correspondingly reducing the cost of making the product) or to potentially enable additional product to be made from existing reactors and processes, for any kinetically reactive rapid gas-liquid system having limited mass transfer. Many oxidation and hydrogenation processes fall into this category, as will be easily appreciated. For example, the oxidation processes for producing ethyl benzene hydroperoxide and t-butyl hydroperoxide, which are intermediates in known commercial processes for producing at the same time respectively propylene oxide and styrene on the one hand and propylene oxide and tert-butyl alcohol on the other hand. another, involves significant reaction times (in the order of from 1 to 4 hours, see "Propylene Oxide", Kirk-Othemer Encyclopedia of Chemical Technology, 3rd edition, vol 19, pp. 257-261 (1982)) and may require multiple reactor vessels. In this regard t-butyl hydroperoxide is conventionally prepared via the oxidation of the liquid phase air of isobutane in the presence of from 10 to 30 percent tert-butyl alcohol, at a temperature of from 95 to 150 degrees Celsius and a pressure of from 2075 to 5535 kPa, in a conversion of 20 to 30 percent isobutane and a selectivity to TBHP (t-butyl hydroperoxide) of 60 to 80 percent and to TBA (tertbutyl alcohol) of 20 to 40 percent. The unreacted isobutane and a portion of tert-butyl alcohol produced are separated from the product stream and recycled back to the hydroperoxide-forming reactor, see also Patent of the United States of America Number: 4,128,587. Ethyl benzene hydroperoxide is also prepared by -Jk an oxidation of liquid phase, in this case of ethyl benzene by air or oxygen at 140 to 150 degrees Celsius and 206-275 kPa, absolute. The conversion to hydroperoxide is reported to be 10 to 15 percent over a reaction time of from 2 to 2.5 hours, see also United States of America Patents Numbers: 3,351,635; 3,459,810 and 4,066,706. A commercially important application relates to the manufacture of epoxides via the olefin hydrochlorines corresponding, for example, epichlorohydrin from allyl chloride, butylene oxide via butylene chlorohydrin and propylene oxide via propylene chlorohydrin. Thus, in a broad sense, the present invention allows a more effective process of making epoxies, or, as just mentioned above, still more widely facilitates two other phases, the reactive gas-liquid processes where some benefit can be gained by improving the mass transfer of the gas in the liquid. In relation particularly to the production of epoxides via an olefin chlorohydrin intermediate, conventionally this is carried out by the formation of the olefin chlorohydrin and thereafter contacting the chlorohydrin with an alkali metal hydroxide in the epoxidation step , to form a product of aqueous saline solution containing at least one epoxide. The apparatus and method of the present invention (as better explained below) are especially convenient to help improve the formation of olefin chlorohydrin. The olefin chlorohydrin, in this connection, is preferably formed by contacting a low aqueous solution of hypochlorous acid chlorides (HOC1) with at least one unsaturated organic compound to form an aqueous organic product comprising at least one olefin chlorohydrin. . The "unsaturated organic compound" may contain from 2 to about 10 carbon atoms, preferably from 2 to 8 carbons, and more preferably from 2 to 6 carbons. The organic compound is selected from a group consisting of substituted and unsubstituted olefins and may be linear, branched, or cyclic, preferably linear. Suitable olefins include amylenes, aleno, butadiene, isoprene, allyl alcohol, cinnamyl alcohol, acrolein, mesityl oxide, allyl acetate, allyl ethers, vinyl chloride, allyl bromide, methallyl chloride, propylene, butylene, ethylene, styrene , hexene and Allyl chloride and its homologues and analogues. Preferred olefins are propylene, butylene, ethylene, styrene, hexene and allyl chloride; the most preferred being propylene, butylene and the allyl chloride. The olefin is preferably unsubstituted, but can also be inertly substituted.

By "inertly" it is meant that the olefin is substituted with any group that does not undesirably interfere with the formation of chlorohydrin or epoxide. Inert substituents include chlorine, fluorine, phenyl, and the like. More detailed additional descriptions of a process Epoxidation and an associated step of chlorohydrin formation of the type summarized herein can be found in U.S. Patent Nos. 5,486,627 and 5,532,389 (which are incorporated herein by reference). Although the preferred embodiment of this method and of the incorporated patents involves the use of low aqueous solutions of hypochlorous acid chlorides, skilled artisans will readily recognize that the method also applies to the use of hypochlorite solutions, typically in the presence of stoichiometric amounts. of chloride, and also to the use of chlorine gas partially or totally dissolved in water. For optimal results, the organic compound is typically added in an amount sufficient to provide a molar ratio of organic compound to hypochlorous acid of low chlorides greater than 0.8. To ensure complete reaction of the hypochlorous acid, the amount of organic compound is conveniently provided in at least one stoichiometric amount. Preferably there is provided from about 0 to 25 mole percent of excess organic compound, and more preferably from about 0 to about 10 mole percent of excess organic compound is fed to the reactor. The unreacted organic compound can then be recycled again to contact the hypochlorous acid. A skilled artisan is fully capable of employing various known methods of recycling unreacted organic compounds when the compounds are supplied in excess of what is necessary for the reaction. The incoming feed of low chloride aqueous hypochlorous acid is typically provided in a concentration of from about 1.0 to about 10 weight percent, preferably from about 2 to about 7 weight percent, and more preferably about 7 weight percent based on hypochlorous acid in water. This provides a good balance between the water requirements and the inhibition of the formation of secondary products. Surprisingly, the use of the shear mixing apparatus of the present invention allows the operation of the process in concentrations approximately 20 percent higher than those which are possible without the use of the shear mixing apparatus of the invention, prior to the formation of an insoluble organic phase - a condition that greatly increases the formation of secondary products. It is desirable to operate at higher concentrations of hypochlorous acid in water, of course, to reduce the size and cost of related processing equipment. The organic compound can be contacted with the hypochlorous acid solution by any method sufficient to form the chlorohydrin. This is typically carried out by introducing the organic compound and the hypochlorous acid solution into a reactor in a manner that allows maximum uniformity of the entire contents of the reactor. Preferably, the contact of the hypochlorous acid solution and the organic compound occurs in a continuous or semi-continuous reactor. In a continuous reactor, such as a continuous tubular reactor, simultaneously the reactants are introduced and the products are removed. In contrast, an example of a semicontinuous reactor would be a reactor that has a specific amount of organic compound already placed in the reactor, then it has a continuous feed of the hypochlorous acid solution fed to the reactor, which produces chlorohydrin products that accumulate in the reactor. It is more preferred that the contact occurs in the presence of mixing in a continuous reactor such as a flow and cap reactor or a re-mix reactor. A flow and cap reactor is one in which reagents are introduced at one end and the products are withdrawn at the other end with little mixing being re-mixed throughout the reactor, for example, a continuous tubular reactor. A re-mix reactor is defined as a reactor in which the products of the reaction are intimately mixed with the fed materials, resulting in a uniform product and reagent concentrations through the reaction vessel. An example of a continuous reactor of this type is a stirred continuous flow reactor (CSTR). The conditions of temperature, pressure and reaction time are not critical. Any condition under which hypochlorous acid and the organic compound react is conveniently used. The hypochlorous acid solution is advantageously fed to the reactor at a temperature of about 30-60 ° C, preferably about 40 ° C. Conveniently, the reaction temperature of hypochlorous acid / organic compound is at least about 40 ° C because lower temperatures require cooling or other cooling. More preferably, the reaction temperature is at least about 60 ° C. Preferably the temperature is less than about 100 ° C, more preferably less than about 90 ° C (to avoid vaporization of water and organic compounds in the reactor), and more preferably less than about 80 ° C (to avoid undesirable increases). in the formation of secondary products that occur above this temperature). When a flow and cap reactor is used, the olefin gas is introduced into the hypochlorous acid solution through a tube perpendicular to the flow of the hypochlorous acid solution. The design of the shear mixing apparatus of the present invention is such, in this context, that the surface velocity of the liquid is at least about 4.6 meters / second, preferably at least about 6.7 meters / second, more preferably at least about 9.1 meters / second and less than about 30.5 meters / second), preferably less than about 15.2 meters / second). The surface velocity of the gas once introduced into the liquid stream is at least about 0.9 meters / second, preferably at least 1.8 meters / second and less than about 9.1 meters / second, preferably less than approximately 6.1 meters / second. The ratio of surface velocity of the liquid against the surface velocity of the gas is at least 1.0, preferably at least about 1.5 and ^ V is less than about 10, preferably less than approximately 8. To satisfy these conditions, more than one of the mixing apparatuses with shear stress may be required since the volume of the gas is typically greater than the volume of the liquid. When multiple devices are used, sufficient space is provided between the devices in a manner than at least about 80 percent, preferably at least about 90 percent Jft, the organic compound is reacted before introducing additional organic compound to the liquid stream. The use of a stirred continuous flow reactor 20 allows the use of larger liquid volumetric flows through the mixing apparatus with shear stress by the use of a recycle line that removes liquid from the reactor, passes it through the mixing apparatus and return to the reactor vessel. In this operation the new hypochlorous acid solution is mixed with the recycle stream before the shear mixer of the invention or is introduced into the vessel of the stirred continuous flow reactor through a separate line. The agitated continuous flow reactor vessel is optionally further provided with a conventional complementary mixing element that maintains a uniform distribution of reagents and products within the vessel, such as a conventional mechanical agitator. The design of the shear-P mixing apparatus of the invention in this particular configuration is such that the surface velocity of the liquid is at least about 4.6 meters / second, preferably at least 6.7 meters / second, more preferably 9.1 meters / second, and less than about 30.5 meters / second, preferably less than about 15.2 meters / second.

The surface velocity of the gas once introduced into the liquid stream is at least 0.9 meters / second, preferably at least about 1.8 meters / second and less than about 9.1 meters / second, preferably less than about 6.1 meters / second.

The ratio of surface velocity of the liquid against the surface velocity of the gas is at least 1.0, preferably at least about 1.5 and is less than about 10, preferably less than about 8. Although only one apparatus of the invention is typically required.

In order to meet these requirements, it is contemplated that additional apparatuses may be employed in a desirable manner depending on the geometry of the reactor and the size of the mixing apparatus with shear stress employed. In the most preferred embodiment where a stirred continuous flow reactor is used, the stirred continuous flow reactor operates isothermally, while a flow and cap type reactor operates commonly adiabatically. The heat of the reaction, therefore, is removed from the stirred continuous reactor as by a * 10 recycle heat exchanger and / or a reactor jacket. To minimize heating or external cooling in the reactor, the heat reaction is preferably matched to the raw material temperatures so that the heating of the reaction raises the temperatures of feed at the desired reaction temperature. Matching temperatures is within the skill in the art. For example, a feed concentration of hypochlorous acid to one molar (about 5 weight percent hypochlorous acid) that reacts with propylene adiabatically raises the temperature by about 55 ° C. Therefore, if a reaction temperature of about 90 ° C is desired, the feed temperature is advantageously about 35 ° C. A smaller distribution between the feed and reaction temperature requires cooling, while higher temperature distribution * between temperatures requires heating. Temperature control is achieved by any means within the skill of the art, such as a jacketed reaction vessel, submersible coils in the reactor, or a heat exchanger in an external recycle line. Conveniently, the pressure is at least approximately atmospheric (approximately 101 kPa), preferably at least 2 atmospheres (202.6 kPa). Higher pressure pressures also increase mass transfer of the organic compound with the hypochlorous acid solution, increasing the total speed of the reaction. Conveniently, the pressure is less than about 1037 kPa of measurement, and more preferably is less than about 691 kPa measurement, because the lower pressure requirements reduce the costs of manufacturing the reactor and reduce the energy costs to introduce the gas into the reactor. * The reaction time for the steps of chlorohydrin formation varies depending on factors such as the reagents used, the reaction temperature, the conversion level The desired volume, the liquid volumetric ratio against gas through the shear mixer of the present invention, excess organic compound, reactor pressure, levels of chlorides in the hypochlorous acid feed, and the feed concentration of hypochlorous acid. An expert In the art, it is capable of determining a sufficient time required for the reaction of the hypochlorous acid with the organic compound. For example, when propylene is used as the organic compound in a stirred continuous flow reactor, and under the most preferred conditions described above, the reaction time can be reduced to as little as about two minutes and more preferably to as little as about 1 minute. Conveniently, the reaction time is less than about 10 minutes and more preferably less than about 5 minutes in order to minimize the size of the reactor vessel necessary to produce a previously selected quantity of the product. The reaction of allyl chloride is faster than that of propylene and thus requires less reaction time, while the reaction of butylene or hexene is lower than that of propylene and requires longer reaction times. The conversion of the hypochlorous acid in the stirred continuous reactor is advantageously at least about 90 mole percent and preferably greater than about 98 mole percent, so that the concentration of hypochlorous acid in the reactor, diluted by water from the reacted hypochlorous acid solution, does not exceed 0.2 percent by weight, and is preferably less than 0.1 percent by weight. Lower conversion levels result in higher yields of chlorinated ketones, such as monochloroacetone (MCA), from the oxidation of the chlorohydrin product, such as propylene chlorohydrin (PCH) and other undesirable byproducts. Advantageously, the conversion is less than about 99.8 mole percent in the stirred continuous flow reactor; Higher conversions, although possible, require longer residence times, and thus, larger equipment to produce a previously selected quantity of product. The aspect of the method of the present invention is maintained with the findings and expressed needs of the references of Motarj emi and Jameson mentioned in the introduction of the present invention and with the aforementioned gas-liquid applications, in accordance with the foregoing. It relates to generating small bubbles in a liquid. The bubbles in many applications preferably have an average diameter of less than about 0.5 millimeters, and the apparatus and method of the present invention are unique in enabling economically making bubbles of this size for these applications., and in other applications the bubbles will still preferably have a diameter of less than about 0.1 millimeter. Apparatus within the scope of the present invention is particularly convenient for use in the aspect of the method. The method comprises two separate actions that serve to put a gas in contact with a flowing liquid. One action places the gas under pressure which is sufficient to generate gas bubbles when a gas is introduced into a liquid, preferably a liquid that flows, by means of at least one opening in an element or member that otherwise separates the gas from the gas. liquid. The other action passes a flowing liquid passing the opening (the openings) at a sufficient linear flow rate to provide a Weber number that exceeds a critical Weber number for a desired bubble size taking into account the physical properties of the gas and liquid. As a practical matter, this expense promotes at least one subdivision of the bubbles initially produced in the opening. The subdivision effectively leads to the generation of small bubbles that have the desired diameter. The method of the present invention thus effectively allows control of the size of the gas bubbles that are generated in a liquid. Apparatus 10, 40, 100 and variations thereof are preferably used in conjunction with the method. The control of the size of the bubbles leads, in turn, to the handling of the mass transfer of the gas to the liquid 20 by means of determining the surface area available for this mass transfer. A number without a dimension, called the Weber number, is used to predict a relationship between the size of the bubbles generated and the fluid that flows. G.J. Jameson, in "Bubbles in Motion", refers, on page 588, to the previous work by D. A. Lewis and J. F. Davidson, "Bubble Splitting in Shear Flow", Trans IChemE, Vol. 60, pages 283-291 (1982). Jameson states that Lewis and Davidson used "critical Weber number" or Wecrit, to describe a critical proportion of 5 forces that seek to divide or subdivide a bubble by surface tension forces that seek to maintain a given bubble size or, if they are strong enough , restore a bubble to a larger size. Exceeding Weber's critical jjj number causes the bubble to split. The present invention uses a field with shear stress created by fluid flowing past an opening from which a bubble is initially generated to control the size of the bubble. If the flowing fluid has sufficient velocity, the shear field will be large enough to exceed the critical Weber number and the bubble will be divided. The division of the bubble will continue until the resulting bubbles have a size that satisfies the critical Weber number. The Weber number is defined by the following equation: 20 We = r * u2 * dm / s where r = density of the liquid u = velocity of the fluid in the field of shear stress 25 dm = diameter of the bubble s = interfacial tension between The phases The present invention is useful with liquids that can be either a coalescent liquid, such as clean water, or a non-coalescing liquid, such as brine wastewater such as that produced from certain industrial processes (wastewater having chloride sodium above 0.9 percent by weight are reported in published literature as being non-coalescent), or a stream of jjj monomer that can be either coalescent or non-coalescent, 10 for example, depending on factors such as hydrogen bonding. "Coalescent" as used in the present, means that the bubbles, once generated, tend to combine relatively rapidly with each other in larger bubbles. "Non-coalescent" as used herein means that once generated bubbles tend to remain as distinct bubbles that maintain their size. The monomer stream or feed stream conveniently contains a polymerization inhibitor that is activated by the gas. Alternatively, the gas could be a reactant in the polymerization reaction where an efficient mass transfer of the gas to the liquid is desired. As yet another example, the gas could be one that is miscible in the liquid. In practical applications, such as the aforementioned wastewater aeration 25 containing brine (eg wastewater from industrial processes containing sodium chloride at levels of 3 percent by weight or greater), by increasing the transfer of Oxygen mass in the waste water containing brine will increase biochemical reaction rates. In other words, the use of oxygen increases as the mass transfer rates are improved. The method and apparatus of the present invention, by generating smaller bubbles than conventional bubble generators effectively improve mass transfer. The improvement comes through the expenditure of energy to create a field of shear stress. The energy expenditure is proportional to the pressure drop through a mixing conduit and the square of the velocity of the liquid. A practical point of decreasing returns in energy expenditure versus bubble size occurs within a range of from about 50 to about 70 kilopascals (kPa), as illustrated in Figure 6. Although the surface area for mass transfer continue to grow with rising energy costs, energy costs may outweigh the benefits realized by increases in mass transfer. A critical point to determine when energy costs become non-economic (and correspondingly, to determine which bubble sizes (although technically possible by the present invention, whether or not they are characterized by an average diameter of 0.5 millimeters or less) are economically achievable) will vary depending on the end use application of choice. In other words, an end use such as promoting the effectiveness of an inhibition of oxygen-activated polymerization can tolerate energy costs greater than the treatment of waste water. It is generally believed, however, that the method and apparatus of the present invention allows smaller bubbles to be generated in a controllable and economical manner for a given application that has hitherto been possible with the known apparatus, and that the method and apparatus of the present invention allows only very small bubble sizes associated with average bubble diameters of 0.5 millimeters or less and especially 0.1 millimeters or less, although as has been noted the generation of these very small bubble sizes may not be economically justified in a given application. The following examples further define, but do not limit, the scope of the invention. Unless otherwise stated, all parts and percentages are by weight.

Example 1 The process according to the invention was carried out in a rectangular acrylic tank of 15.2 by 15.2 centimeters in cross section, 91.4 centimeters high. The tank was filled to a level of 75.4 centimeters with a 10 percent by weight solution of NaCl in water. The tank had an open top, and the temperature was 20 ° C. The two-stage mixing device used in this Example was similar to that shown in Figure 1. It consisted of an internal air duct (15) of stainless steel with an external diameter (OD) of 0.9 centimeters which was closed at one end and which it had three holes of 0.04 centimeters punched into a space of 120 degrees, 0.9 centimeters from the closed end. The external portion of the body of the two-phase mixer consisted of a 0.9 cm PVC pipe union nozzle that had been machined to have an internal diameter (ID) of 1.1 centimeters. The rest of the device consisted of a 1.3-cm PVC tube T, a 0.9-centimeter pipe connector with a 1.3-centimeter male stainless steel pipe thread which was drilled to pass the 0.9-centimeter tube, and two nozzles 1.3 to 0.3 centimeters of tube. One of the nozzles was connected to one of the ends running from the T and the 0.9 cm union nozzle was attached to the nozzle. The connector of the tube to the pipe was connected to the other end that runs from the T and the 0.9-centimeter tube inserted through the connector, closed the first end first until the tip of the tube finished passing the end of the union nozzle , leaving the three holes of 0.04 centimeters just inside the union nozzle. The two-phase mixing device was connected to a 1.3 cm female coiled port in the center of the bottom of the tank used the second nozzle, so that the mixer discharged vertically up into the tank. The discharge pipe of a centrifugal pump March TE-5C-MD was connected to the remaining door of the T. This pump suction pipe was connected to a coiled 1.3 cm female pipe door in the corner of the tank bottom. A Wallace and Tiernan flow meter model 5120M12333XXL Varea-Meter was placed in the discharge pipe to measure the waste of the liquid. An air supply tube was connected to the 0.9 centimeter tube and the air flow rate was measured with a Matheson mass flow transducer with a Matheson Multiple Flow Controller model 8274. The fluid was 1.75 gallons per minute (GPM) (11 x 10 ~ 5 cubic meters per second (m3 / sec)) and the air flow rate was 1,235 standard liters per minute (SLM, being the standard conditions of 0 degrees Celsius and a pressure of 760 millimeters of mercury). At these flow rates, the tank filled with small bubbles and had a milky, almost opaque appearance. A 0.3 cm thick black rubber sheet was hung from the top of the tank and extended down into the tank approximately 0.46 meters (m) below the liquid level. This blade was placed a few millimeters (mm) from the front wall of the tank, creating a 5 regrowth that made it possible to see individual bubbles in this surface field. A video camera with an accessory microscope was used to videotape a small area just inside the acrylic wall of the tank. An mm grid printed on a transparency stuck to the tank and was also recorded on video in order to calibrate the magnification of the microscope. The videotape was viewed using a video cassette recorder (VCR) with a Jog / Shuttle accessory, so that the individual frames of the videotape were could analyze. The bubbles shown in the pictures of the videotape were measured on the screen of a video monitor using a millimeter scale. The frames of the videotape showing the grid of 1 millimeter were also seen in this way and the grid divisions were measured on the same monitor. This established that the amplification was approximately 60 to one (1.0 millimeters measured = 0.0154 millimeters in real size). Twenty bubbles varying in size from 0 to 0.046 millimeters were observed on a painting together with ten varying in size from 0.47 to 0.154 millimeters, four varying in size from 0.155 to 0.231 millimeters, and three varying in size from 0.232 to 0.385 millimeters. The smallest possible bubble to be measured was 0.0154 millimeters and the largest bubbles observed in the 5 'square were 0.385 millimeters.

Use 2 The oxygen transfer test was carried out according to the clean water procedure in the non-state stable of the North American Society of Civil Engineers (ALCE) ("A Standard for the Measurement of Oxygen Transfer in Clean Water. "Amer. Soc. Of Civil Eng., New York, N.Y. (1984)) in a mixing device with shear stress designed for saline wastewater and constructed in a manner of the apparatus shown in Figure 2. Table I shows the results of the test along with comparable data from a commercially available thick bubble diffuser: twenty * SAE = Standard Aeration Efficiency in pounds of oxygen per horsepower per hour. ** Not an example of the invention E.F = shear stress For the purposes of a direct comparison between the shear mixer and the thick bubble diffuser, the alpha values (defined as the ratio of kLa for two systems tested). In this case, an established reference standard was Run 1 for clean water with the thick bubble diffuser (CBD). Using runs 1 and 4, alpha = kLa20 mixer with shear stress (Run 4) / kLa2o CBD (Run 1) = 3.9, in clean water. Using Runs 1 and 7, alpha = kLa2o shear mixer (Run 7 / kLa20 CBD (Run 1) = 9.6, in 5% brine The data presented in Table I demonstrate the effectiveness of the present invention in relation to a conventional coarse bubble diffuser An alpha value greater than unity (1.0) indicates a more effective mass transfer for the mixer with shear stress relative to the thick bubble diffuser.It is believed that the increase in mass transfer is derived, when less in part, of the increased surface area The increased surface area is largely due to an average bubble size for the mixer with shear stress that is less than a typical average bubble size for a thick bubble diffuser. of the brine test solution (Run number 7) suggests that the mass transfer improvements relative to a thick bubble diffuser in clean water (run number 1) are due, at least in part, to the non-coalescing nature of the liquid. In other words, bubbles, once formed, tend to retain their identity instead of combining or coalescing with other bubbles.

Example 3 - Summary of gas / liquid mixers installed in monomer processing. To eliminate the formation of free radical polymers in the first seven stages of a ten-stage reactor, seven gas / liquid mixers of the invention were installed, one in each stage, to improve air dispersion in the mixture of the reaction. The shear mixers were like the one shown in Figure 2 (Apparatus 40) except for having only one opening / hole 54 in the first conduit 50. Oxygen in air activated a free radical inhibitor in this system. Before the installation of these shear mixers, polymer was present in stages 1 to 10, and approximately 0.014 cubic meters of the polymer was collected by filtration every 8 hours.

The gas / liquid shear mixers operated with an air flow rate of 11.5 SLM and a solvent expenditure of 6.3 x 10"5 m3 / second.The mixers with shear stress had an orifice diameter (with respect to the diameter of the single hole 54 in each) of 0.5 centimeters and one orifice length (from the single hole 54 to the second, outlet end 52 of the conduit 50 in each mixer) of 2.5 centimeters. Air and solvent were mixed outside a given reactor and transported through a deep tube to the mixer with shear stress placed in the reactor. Since the installation of the mixers with shear stress, polymer has been eliminated in the first seven reaction stages and the formation of the polymer has been reduced to 0.007 cubic meters every 8 hours. Although the mixers in this example only have one opening to form gas bubbles, the additional openings should increase this performance. Expert technicians can easily determine how many additional openings their application could satisfy without undue experimentation. Example 4 A mixer with shear stress was installed in a 56.6 cubic meter container that was being used to strip water by aeration from an organic compound susceptible to the polymerization of free radicals. Oxygen in air activated a free radical inhibitor in this system. The gas / liquid mixer (as used in Example 3) operated at 119.7 SLM of air flow and at 0.19 cubic meters per minute of monomer flow rate recycled. The mixers with shear stress have an inner diameter of 2.4 centimeters) and a length of approximately 1.2 meters. The initial batch contained approximately 2 percent, by weight, of water in an organic monomer and was stripped by air to less than 0.0500 percent in two hours. The conditions of dispossession were absolute pressure of 80 millimeters of mercury and 60 ° C. Of the four lots stripped by air in this way, none formed any polymer.

Example 5 A container 0.6 meters in diameter and 4.57 meters in height with a liquid height of 4.27 meters was filled with acclimated activated sludge from an industrial wastewater treatment facility. The total suspended solids (TSS) was 2600 milligrams / liter. The upper space of 0.086 cubic meters was purged with nitrogen gas at 5 SLM measured by a Brooks Instrument mass flow controller (model 5851 I). Feeding liquor was supplied at 0.19 cubic meters per hour for a residence time of 6.3 hours. The food liquor was waste water from an industrial oxygenated hydrocarbon plant with a salinity of 70 grams / liter (approximately 7 weight percent). The substrate concentration was 150 milligrams / liter. The system was ventilated using a thick bubble disperser with an orifice diameter of 0.005 meters to 1.14 SLPM of oxygen, as measured by the Brooks Instrument Model 5851 I mass flow controller, and allowed to reach a steady state for 1 hour. The concentration of dissolved oxygen was 0.1 milligram / liter measured by an Ingold Electronics Inco DO Sensor / Transmitter (model 4300), the measurement measured by a multiple channel oxygen monitoring system of Teledyne Analytic Instruments model TAI 322, giving as resulted in a calculated oxygen transfer efficiency of 23 percent by 5 percent. At this point, the oxygen flow was abruptly redirected to a blender device representative of the present invention, as shown in Figure 2, remaining constant with oxygen flow and all other parameters remaining constant. The «10 wind oxygen concentration immediately began to decrease and the calculated oxygen transfer efficiency began to increase. After 7 minutes, the oxygen transfer efficiency was 50 percent with a wind oxygen concentration of 10.2 percent. cent. At 13 minutes, the transfer efficiency was 70 percent with a wind oxygen concentration of 6.4 percent. At 52 minutes, the efficiency of the transfer was 90 percent with a wind oxygen concentration of 2.2 percent that established a new steady state value. After this, the dissolved oxygen began to rise rapidly to a steady state value of 5 milligrams / liter.

Examples 6-8 Examples 6-8 and Comparative Examples A and B were carried out in a 30 liter, vertically mounted, cylindrical stirred continuous flow reactor equipped with 4 vertical deviators and an agitator with one or two propellers . Comparative examples A and B used a lower impeller having a diameter of 12.7 centimeters Chemineer ™ CD-6 and an upper propeller having a diameter of 12.7 inches Lightning ™ A-315. Examples 6-8 used only the Lightning ™ A-315 propellant. For examples 6-8 it was added continuously «10 aqueous solution of hypochlorous acid near the center of the propeller. The liquid was pumped from the bottom of the stirred continuous flow reactor and returned to the stirred continuous flow reactor via a recycle line which was connected to a mixing apparatus with shear with a Inner diameter of 0.719 centimeters of the present invention (constructed as in Figure 2) mounted on the external wall of the container, with the most widespread recycle line of the mixing apparatus with shear stress through the wall of the container to a just point under the lower part of the propeller. The olefin gas entered this mixing device perpendicular to the flow of the liquid through a tube with an internal diameter of 0.719 centimeters, the product was continuously removed from the container at a speed equal to the feed rate in order to maintain a constant level of liquid in the stirred continuous flow reactor. For comparative samples A and B the aqueous solution of hypochlorous acid was added continuously near the center of the lower propellant. The olefin gas was added under the lower propellant through a dispersion ring of 11.60 centimeters in diameter constructed from a 0.707 centimeter tube. The dispersing ring had twelve holes of 0.08 centimeters in diameter evenly spaced around the ring. The product was continuously removed of the container through a lower pump in order to maintain a constant liquid level in the stirred continuous flow reactor. Example 6 - Production of propylene chlorohydrin using the shear mixing apparatus of the invention. The stirred continuous reactor described above was operated at a pressure of 50 psig, 69 ° C, and an agitator speed of 400 revolutions per minute (rpm). A 5.8 weight percent solution of hypochlorous acid at 115 kg / hr was added along with 97.5 kg / hr of water. The liquid was recycled at a rate of 1451 kg / hr by means of the mixer, providing a superficial liquid velocity of 9.4 m / sec. Propylene gas was added via the mixer at a rate of 5.67 kg / hr, for a gas surface velocity of 3.05 m / sec and a liquid to gas velocity ratio of 3.1. The product was continuously stirred from the bottom of the stirred continuous flow reactor at a rate of 219 kg / hr. The reaction time was 2 minutes to provide a 99 percent conversion of hypochlorous acid and a yield of propylene chlorohydrin product of 98.0 percent based on propylene. Comparative Example A - Production of propylene chlorohydrin with the conventional gas disperser. The stirred continuous reactor described above was operated at a pressure of 50 psig, 71 ° C, and an agitator speed of 560 revolutions per minute. A 5.65 percent hypochlorous acid solution was added to 52. 2 kg / hr together with 28.5 kg / hr of water. New propylene was added by the ring dispersion at 2.1 kg / hr together with 4.5 kg / hr of recycled propylene from the upper space of the reactor. The product was continuously stirred at 83 kg / hr.

The reaction time was 12 minutes, with a 99.8 percent conversion of hypochlorous acid and a yield of 97.5 percent propylene chlorohydrin product based on propylene. Example 7 - Production of butylene chlorohydrin using the shear mixing apparatus of the invention. The procedure of Example 6 was repeated using butylene gas at a rate of 3.7 kg / hr. The reaction conditions included pressure of 20 psig, 66 ° C, and agitation speed of 400 revolutions per minute for the single propellant. The liquid feed was a 5.6 weight percent solution of hypochlorous acid at 68 kg / hr along with 5 76.2 kg / hr of water. The liquid was recycled through the mixer with shear at a rate of 1542 kg / hr, for a surface velocity of 9.7 m / sec. The surface gas velocity was 3.59 m / sec, providing a gas-to-gas ratio of 2.7. The product * 10 was continuously removed from the stirred continuous reactor at 148 kg / hr. The reaction time was 3 minutes, with a hypochlorous acid conversion of 99.8 percent and a butylene chlorohydrin product yield of 94.9 percent based on butylene. 15 Comparative Example B - Production of butylene chlorohydrin with the conventional aas dispersant. ^^ k The procedure of Comparative Example B was followed by using butylene for the gas feed at 2.2 kg / hr in the ring disperser. The conditions of the reaction included pressure of 20 psig, 52 ° C, and agitator speed of 550 revolutions per minute. The liquid feed was 4.9 weight percent hypochlorous acid solution at 43.3 kg / hr together with 22.2 kg / hr water. The product was continuously stirred at 71.6 kg / hr. The reaction time was 15 minutes with a conversion of 99.5 percent of the hypochlorous acid and a yield of the butylene chlorhydrin product of 94.2 percent based on butylene. Example 8 - Production of hexene chlorohydrin using the shear mixing apparatus of the invention The procedure of Example 6 was again followed using 3.3 kg / hr of 1-hexene instead of propylene. Reaction conditions included a pressure of 3.8 psig, 78 ° C, and agitator speed of 450 revolutions per minute. The liquid food was a hypochlorous acid solution at 2.14 percent. The reactor liquid was recirculated through the mixer at a rate of 1397 kg / hr for a liquid surface velocity of 8.8 m / sec. The surface velocity of the gas was 8.8 m / sec, for a gas-to-gas ratio of 1.0. The product was continuously stirred at 66.9 kg / hr. The reaction time was 14.4 minutes with a 100 percent conversion of hypochlorous acid and a yield of 88.2 percent hexene hydrochlorine product based on hexene.

Claims

1. A mixing apparatus with shear stress, comprising: at least one conduit for transporting a first fluid to be mixed, which has a first open end that receives the first fluid to be mixed and a second closed end, being defined one or more openings in each of the conduits near the second end thereof, through which a fluid received at the first open end leaves said conduit, - a mixing body defined generally around the conduit or conduits and having a first a closed end defining an opening or corresponding openings therein through which the respective conduit or conduits pass, the mixing body further has a second end defining a restricted orifice with each of the conduits and with respect to a hollow space enclosed by the mixing body and defined between the first closed end and the second end of the mixing body, with the openings in one of the conduits placed substantially in the restricted hole associated with a given conduit; and a second fluid supply conduit in fluid communication with the hollow space enclosed by said mixing body, to provide a second fluid thereto which passes through one or more restricted holes in the second end of the mixing body and which is mixed in a shearing manner the first fluid supplied from the openings located in the respective restricted orifice. The apparatus of claim 1, wherein the conduit or conduits for supplying the first fluid to be mixed are each fitted into a corresponding opening in the first end of the body by a substantially leak-proof seal. The apparatus of claim 1, wherein the restricted orifice associated with a given conduit is in the form of an annular space, having the shape of a hollow, straight circular cylinder. The apparatus of claim 1, wherein the openings near the second closed end of a given conduit are separated from one another. A mixing apparatus with shear stress, comprising: one or more conduits for providing a first fluid to be mixed, with each conduit defining one or more openings therein over a length of said conduit; a mixing body having a first end '? ^ and a second end defining between the first and second ends a generally enclosed hollow space with which a fluid supply conduit is in fluid communication, each having the first and second ends of The mixing body defined therein is a respective corresponding opening for receiving a conduit carrying the opening therethrough so that the openings in the conduits cause the first fluid to be mixed to flush with the fluid. the hollow space. The apparatus of claim 5, wherein each of the conduits carrying the opening forms a substantially leak-proof seal with the corresponding openings in the first and second ends of the mixing body through which the conduit passes. The apparatus of claim 6, wherein the openings in each of the conduits carrying openings are separated from each other. 8. A shear mixing apparatus comprising a hollow gas and liquid receiver subassembly, a bubble generating sub-assembly and, optionally, a handle, the subassembly receiving gas and liquid operatively connected to, and in fluid communication with , the sub-assembly that generates bubbles. The apparatus of claim 8, wherein the sub-assembly receiving gas and liquid comprises: ~~ "~ a central conduit having an open inlet end for receiving a liquid therein and an outlet end in communication of fluids with the bubble generating sub-assembly, and a housing receiving gas that is generally disposed about and is separated from the central conduit so as to define a passage for the flow of a gas therethrough to the generating sub-assembly of FF bubbles, and which includes at least one passage that receives 10 gas to receive a gas ugh it and communicate it via the passage to the subassembly that generates bubbles, the housing that receives gas at one end being connected in a gas-tight relationship with the central duct, at a further point. close to the entrance end of the central duct 15 to its outlet end. 10. The apparatus of claim 9, wherein the -M subassembly that generates bubbles comprises a base plate that is attached to the central conduit adjacent to its outlet end in a gas-tight relationship, a housing of The gas and liquid distribution to contain and distribute gas and liquid received from the gas receiving housing and the central conduit, respectively, and which is attached to the base plate in a gas-tight relationship, and a cover plate that in turn joins the distribution housing of Gas and liquid in a gas-tight relationship, the gas and liquid distribution housing having a central funnel-shaped liquid expansion housing, which with the base and cover plates divides the sub-assembly that generates bubbles in a chamber upper, liquid expansion and lower, gas expansion chamber, the funnel-shaped fluid expansion housing having a hollow rod that fits into a gas-tight seal over a portion of the central conduit near the end of the outlet of the central conduit and a peripheral extension projecting outwardly from the hollow rod having defined therein a plurality of openings that are in fluid communication with the gas expansion chamber and a plurality of fluid channels that are in fluid communication with the liquid expansion chamber, the openings being in fluid communication with the channels s of fluids to mix the gas and liquid transported ugh them. 11. The apparatus of claim 10, wherein the fluid channels are separated from one another by fluid diverters that are defined in the peripheral extension projecting outwardly from the hollow rod. 1

2. A method for generating gas bubbles in a liquid comprising: a. putting a gas under a pressure that is sufficient to generate gas bubbles when the gas is introduced into a liquid by means of at least one opening in a member or element that separates the gas from the liquid; and b. flow the liquid past the opening at a selected linear flow rate to provide a Weber number that exceeds a critical Weber number for the gas and liquid, so that bubbles having a desired diameter are produced in the liquid. The method of claim 12, wherein the gas is reactive with the liquid or a component contained in the liquid. The method of claim 13, wherein the reactive gas is at least one of chlorine, bromine, iodine, oxygen or an oxygen-containing gas. 15. The method of claim 14, wherein the oxygen-containing gas is air. The method of claim 12, wherein the gas is, or includes at least one gas that is miscible with the liquid. 17. The method of claim 16, wherein the liquid is methylene chloride and the gas includes phosgene. 18. The method of claim 12, wherein the liquid is a non-coalescing liquid. The method of claim 18, wherein the non-coalescing liquid is saline waste water. The method of claim 19, wherein the liquid is a stream of waste water and the gas is oxygen, air or air enriched with oxygen. The method of claim 12, wherein the velocity of the flowing liquid is at least about 6.1 meters per second. 22. The method of claim 12, wherein the liquid is a stream of monomer containing a polymerization inhibitor that is activated by oxygen, and wherein the gas is oxygen or a mixture of gases containing oxygen. 2

3. The method of claim 12, wherein the linear flow velocity of the liquid is selected such that the bubbles produced therein are characterized by an average diameter of less than about 0.5 millimeters. The method of claim 23, wherein the linear flow rate of the liquid is selected such that the bubbles produced therein are characterized by an average diameter of less than about 0.1 millimeter. 25. The method of claim 12, wherein the liquid is an aqueous solution of hypochlorous acid with low chlorides, an aqueous solution of hypochlorite or chlorine dissolved in water, and the gas comprises an unsaturated organic compound that is reactive under the conditions of mixing with one or more components of the liquid to form reaction products including an olefin chlorohydrin product. 26. The method of claim 25, wherein the unsaturated organic compound is selected from the group consisting of propylene, butylene and allyl chloride. 27. The method of claim 26, wherein the unsaturated organic compound is propylene or allyl chloride. The method of claim 27, wherein the unsaturated organic compound is propylene, and the olefin chlorohydrin formed therefrom is propylene chlorohydrin. 29. The method of claim 28, wherein the liquid is an aqueous solution of hypochlorous acid of low chlorides containing from about 2 to about 7 weight percent hypochlorous acid in water. 30. The method of claim 29, wherein the concentration of hypochlorous acid in water is about 7 weight percent. 31. The method of claim 25, wherein the ~ Wr liquid is an aqueous solution of hypochlorous acid of low chlorides that contains from approximately 2 to 20 about 7 weight percent hypochlorous acid in water. 32. The method of claim 31, wherein the concentration of hypochlorous acid in water is about 7 weight percent. 33. A method for generating gas bubbles in a liquid having an average diameter of less than about 0.5 millimeters, the method comprising using the apparatus of claim 1 to introduce the gas into a zone of shear stress established by the flow of the liquid through a restricted orifice of the apparatus, the liquid flows in such a manner as to establish a pressure drop through the restricted orifice of less than about 49,000 passages and the gas flowing at a rate sufficient to establish a pressure drop between the conduit and the Associated restricted hole of less than approximately 35,000 pascals. 3

4. In a method for producing an olefin chlorohydrin by combining an unsaturated organic compound in the gas phase with a liquid of hypochlorous acid solution low in chlorides under suitable conditions to form the olefin chlorohydrin and in a reactor of the mixing type again, the improvement comprising increasing the mass transfer of the unsaturated organic compound from the gas phase in the liquid solution of hypochlorous acid by supplying the unsaturated organic compound to the liquid solution of hypochlorous acid in the form of small bubbles having a smaller average diameter of approximately 0.5 mm. 3

5. The process of claim 34, wherein the unsaturated organic compound is supplied in the form of an average diameter of less than about 0.1 millimeters. 3

6. In an interfacial process to produce polycarbonate, where the dihydroxy compound is made 5 reacting with a carbonic acid derivative in a reaction mixture which is characterized as having both an aqueous phase and an organic phase in which the polycarbonate product is soluble and accumulates, and in addition where the carbonic acid derivative is supplied to the reaction mixture when at least partly as a gas, the improvement comprises supplying the gaseous carbonic acid derivative to the process in the form of small bubbles having an average diameter of less than about 0.5 millimeters. 3

7. The process of claim 36, wherein the gaseous carbonic acid derivative is supplied in the form of small bubbles having an average diameter of less than about 0.1 millimeter.