Self-flow

The confined type of aquifer has a hydraulic pressure (static head) that is on a higher level than the top of the aquifer. This artesian pressure can sometimes reach above the surface level resulting in self flowing wells (artesian wells). 

The pastelike mixture is sent by nitrogen flow into hydrolyser 12, which has been filled with hydrochloric acid (2-3% ), prepared in advance and cooled to 4 °C. From batch box 13, the concentrated hydrochloric acid self-flows into the hydrolyser, which has been filled with a necessary amount of water. The hydrolyser has an agitator and a jacket for cooling with Freon. After the reactive mixture is treated with hydrochloric acid, the unreacted magnesium turns into magnesium chloride, which dissolves in... 

The chlorination of tris(y-trifluoropropyl)silane is achieved in the carbon tetrachloride medium. First, carbon tetrachloride from batch box 29 and tris(y-trifluoropropyl)silane from receptacle 27 self-flow into chlorinator 28. Gaseous chlorine passes through a receiver and a glass cotton filter (not shown on the diagram) and is also fed into the chlorinator. The process is conducted at atmospheric pressure and at the temperature of 23-26 °C, which is supported by water sent into the apparatus jacket. Above the chlorinator there is backflow cooler 30 cooled by Freon. The... 

The first rectification stage. From collector 10 the mixture of methyl-chlorosilanes is periodically fed into pressure container 11, from where at 50-65 °C it is sent through heater 12 (by self-flow) onto the feeding plate of rectification tower 13. From the tower the tank liquid (methyltrichloro-silane, dimethyldichlorosilane and tank residue) flows into tank 14, where the temperature of 80-90 °C is maintained, and from there is continously poured into collector 22. After the tower, vapours of the head fraction at a temperature below 58 °C, consisting of the rest of methylchloride, di- and trichlorosilane, dimethylchlorosilane, methyldichlorosilane and the azeotropic mixture of silicon tetrachloride and trimethylchlorosilane are sent into refluxer 15, cooled with water, and into refluxer 16, cooled with salt solution (-15 °C). After that, through cooler 17 the condensate is gathered in receptacle 19. Volatile products, which did not condense in reflux-ers 15 and 16, are sent into condenser 18 cooled with Freon (-50 °C). There they condense and also flow into receptacle 19. As soon as it is accumulated, the condensate is sent from receptacle 19 into collector 20. 

Separation of head fractions. The head fraction, which is obtained at the first stage of continuous rectification of methylchlorosilanes, from collector 20 self-flows into tank 44. The temperature in the tank in the beginning of the process is maintained at 60-70 °C, and at the end it should be from 90 to 95 °C. Vapours from the tank rise up tower 40 and enter reflux-ers 39, cooled with water and salt solution (-15 °C) from there, part of condensate is returned to reflux tower 40, and the rest is sent through cooler 38 into receptacles 41 and fed into collectors 43. 

The reaction gases from the higher part of reactor 5 enter filter 6, then cooler 7, cooled by salt solution after that, the abgases enter the abgase purification unit (not shown in the diagram). The condensate from the cooler self-flows into receptacle 8 and is poured into tanks 9 as it accumulates. The average composition of the condensate is (%) ... 

From container 18 dimethyldichlorosilane is sent into batch box 1 placed over apparatus 2, where a 2% solution of the initiator in dimethyldichlorosilane is prepared. Apparatus 2 is an enameled flask with an agitator and a filling hatch. While the agitator operates, one sends there dimethyldichlorosilane and adds the initiator solution in the amount necessary to form a 2% solution. After 30 minutes of agitation at 20 °C the mixture of dimethyldichlorosilane and initiator is poured into intermediate container 17, from where it is periodically pumped into pressure batch box 4. After that, the mixture self-flows through rotameter 6 into chlorinator 5. The chlorinator is a steel cylindrical apparatus with a heating jacket and a thermometer pocket the lower part of the apparatus contains a distribution device which feeds chlorine. The temperature in the chlorinator is maintained within 65-70 °C and regulated with vapour sent into the jacket of the apparatus and with the speed at which chlorine is fed. 

The raw methylphenyldimethoxysilane from collector 9 and the intermediate fraction from receptacle 15 self-flow into tank 10. After the loading is finished, the heater of the tank is filled with vapour. After the reflux appears in the box, the tower operates in the self-serving mode for 1 or 2 hours then the rest of methyl alcohol and toluene are distilled. The vapours pass through tower 11, refluxer 12 and cooler 13 the condensate enters receptacle 14. Methyl alcohol and toluene are distilled when the tern-... 

First druck filter 8 is filled with coarse calico, filter paper and glass cloth and compressed with nitrogen (0.3 MPa). The pressure should not fall for 10 minutes after that it is reduced to atmospheric. Then reactor 18 is filled from batch box 17 with self-flowing methylphenyldimethoxysilane and newly dried active coal (1-2% of the product weight). After that, the agitator is switched on and the reactor contents are heated to 60-70 °C by sending vapour into the jacket. At this temperature the mixture is agitated for 2-4 hours and then analysed. 

Reactor 9 is used to methacrylate the acetoxysilane mixture. First, back-flow condenser 12 is switched on the agitator is switched on and the jacket of the apparatus is filled with vapour then the contents of reactor 9 are heated to 60°C. At this temperature glycolmethacrylate self-flows from batch box 10 at such speed that the temperature in the reactor does not exceed 65°C. After the glycolmethacrylate has been loaded, the contents of reactor 9 are agitated at 60-65°C for one more hour then condenser 12 is switched into the direct operation mode, vacuum is created (the residual pressure is 130-80 GPa), and acetic acid is distilled into receptacle 13 at 40-50 °C (in vapour) reactor 9 is periodically sampled to determine the acid number (a.n.). If the analysis is satisfactory (a.n. = 450-500 mg/g), reactor 9 is loaded with toluene from batch box 11. 

Toluene vapours are sent into cooler 13 to condense. The condensate is collected in receptacle 14. First, toluene is distilled at atmospheric pressure and 110-120 °C, then, vacuum is gradually created in the system. The final distillation is carried out at 110-120 °C and the residual pressure of 200 GPa, until the toluene content in the product is not more than 1 %. When the analysis is positive, the distillation of toluene is stopped and the product is cooled to 50-60 °C by sending water into the tank jacket. The distilled toluene from receptacle 14 self-flows into settling box 15, where it is separated from water and mechanical impurities. Purified toluene can be re-used in the production of oligomethylsiloxanes. 

The hydrolytic condensation of ethyl paste is carried out in the following way. Ethyl paste continuously self-flows from the top part of the separator through a siphon into forehydrolyser 8 recirculating hydrochloric acid is sent there from batch box 9 through cooler 10. The jacket of the forehydrolyser is filled with water. The vapours condensed in backflow condenser 11. 

From the hydrolyser the products of condensation enter settling box 18 through a siphon and a hydraulic gate. The bottom layer, hydrochloric acid, self-flows through cooler 19 into collector 20 it is then pumped into batch box 9 to be used at the forehydrolysis stage. The top layer, the acidic... 

It is also possible to distil fractions I, II and III below 185 °C in vapour (fraction la) or fractions I and II below 150 °C in vapour (fraction lb). Fractions I-IV self-flow or are sent by vacuum from receptacles 3 into collector 7, and fractions la and lb into collector 8. After the distillation is completed, the electric heating of the tank is switched off, the vacuum pump is stopped and tank 1 is filled with nitrogen (0.07 MPa). When the pressure in the system is atmospheric, the tank residue which boils above 250 °C (at 1.3-6.6 GPa) is sent by vacuum through cooler 4 into batch box... 

The reaction of heterofunctional condensation is carried out in reactor 5, which is a steel enameled apparatus with a water vapour jacket and an anchor agitator. Reactor 5 is loaded at a residual pressure of 730 200 GPa with a,eo-dihydroxydiphenylsiloxane, the product of dihydroxydiphenylsilane condensation a calculated amount of the toluene solution of triace-toxymethylsilane self-flows at agitationffom batch box 6. 

Apparatus 3, which has an agitator, is filled with methyltrichlorosilane and toluene. The mixture is agitated for 30 minutes, analysed to determine the chloroion content and poured by self-flow into weight batch box 5. 

Tributoxyphenylsilane is produced when phenyltrichlorosilane interacts with butyl alcohol in the 1 3.3 mole ratio the synthesis is carried out in enameled apparatus 7. Phenyltrichlorosilane (the 196-202 °C fraction, the chlorine content is 49-50.5%) self-flows from batch box 2 into pre-dried apparatus 1. The agitator is switched on, and anhydrous butyl alcohol is sent from batch box 3 at such speed that the temperature in the reactor does not exceed 30-35 °C. After the whole alcohol has been introduced, the reactive mixture is heated to 90-100 °C (gradually, for 7-8 hours). At this temperature and agitation the mixture is held for 7-10 hours and sampled for the chlorine content, which should not exceed 1.5%. The obtained product is cooled to 80-85 °C by sending water into the jacket of the reactor. The hydrogen chloride released in the reaction is withdrawn into a water-flushed hydroejector and in the form of weak hydrochloric acid sent to biochemical purification. 

When a certain polymer content (30-35%) is observed, the distillation is stopped and the jacket of the condenser is filled with water. Varnish is cooled down to 30-40 °C and self-flows into settling box 10. After settling and separating mechanical impurities, varnish is purified in the ultracentrifuge and sent into the collector. 

The distilled toluene vapours enter water cooler 17, a steel enameled vertical heat exchanger of the vessel in a vessel type with the heat exchange surface of 4 m2. There toluene condenses and is collected in collector 18, from where it self-flows into settling box 19. The settled toluene is sent to regeneration and re-used in manufacture. 

Whether the toluene distillation and product polycondensation is finished, is determined by viscosity or gelatinisation time, and by solid residue. The jacket of apparatus 15 is filled with water to cool the varnish to 40 °C the cooled varnish self-flows into settling boxes 20. After settling, the varnish is sent to ultracentrifuge 21, and the waste accumulated in the bottom part of the settling boxes is periodically loaded off into containers and used to paint factory equipment. 

To obtain resin, the hot product of condensation is poured through the lower drain of condenser 18 to obtain varnish, the resin in condenser 18 is dissolved with ethyl alcohol, which self-flows into the apparatus from batch box 21. While the resin is dissolved, cooler 19 operates in the inverse mode. The obtained varnish is loaded by vacuum into settling box 22, where it is settled at ambient temperature for a long time (24-48 hours) to separate mechanical impurities. There is also a possibility for additional centrifuging in ultracentrifuge 23 for complete elimination of mechanical impurities, as well as clarification" of the varnish. The finished poly-methyl(phenyl)silsesquioxane varnish is sent from the centrifuge into container 24 and packaged. 

It is necessary to batch the mole ratios of organochlorosilanes exactly therefore, they are in turns sent from batch boxes 2, 3, 4, 5 and 6 into batch box 7 and after weighing self-flow into mixer 8. The mixer is also filled with a calculated amount of toluene from batch box 1. After that the reactive mixture is agitated with cooling for appoximately 30 minutes, after which the chloroion content is determined. The prepared mixture of organochlorosilanes and toluene is sent by nitrogen flow (<0.07 MPa) into weight batch box 9. 

The neutral product in the hydrolyser is sampled to determine the solid residue content (10-15%), filtered through portable filter 12 with a metal mesh and poured into vacuum distillation tank 13 to distil toluene. The distillation is carried out in two stages the first takes place under atmospheric pressure to 50-55% concentration of the product the second, at a residual pressure of 860-870 GPa and 80-100 °C until the solid residue content is not less than 97%. Toluene vapours are sent into water cooler 14 to condense. Toluene is poured into collector 15. Raw toluene with impurities of volatile products and water self-flows from receptacle into settling box 16, where it is separated from them. Then it is sent to regeneration and re-used in manufacture. 

Acid waste waters from silicone production enter neutraliser 9, a concrete container with two agitators, lined with acid-resistant tile from epoxy resin. Here the waste waters are neutralised with lime milk, which is automatically sent from reservoirs 6 with pumps 8. The pumps automatically switch off when pH in the neutraliser is 8-10 and switch on when pH is below 5. Neutral waste waters continuously self-flow through a collector into receiving reservoir 10 as they accumulate, they are automatically sent with pumps 11 for averaging and mechanical purification. 

The sediment from the conical bottoms of the settling boxes is continuously withdrawn into reservoir 17. It is partially removed as dirt and partially sent with pumps 18 and 26 to installation 27 to dehydrate. At the stage of biochemical purification the clarified waste waters from settling boxes 16 self-flow into the top channel of the clarified water of aerotank 10. The aerotank is a six-section open concrete precast reservoir with bubble and aeration systems. All sections of the aerotank function parallel to each other. Each consists of two corridors the oxidation corridor, where the process of biochemical purification takes place, and the regeneration corridor, which serves to prepare silt for purification in the oxidation corridor. 

The regeneration time is determined by the time in which silt passes from the beginning of the regeneration corridor to the beginning of the oxidation corridor. Purified waste waters self-flow out of settling boxes 22 through pans into dirt settling box 25. Dirt is removed from there as it accumulates. 

Titanium tetrachloride can also be purified from impurities by the continuous technique. The installation for continuous purification consists of several vertical pipe coolers. Liquid products of the reaction are sent into the first cooler, which is located a little higher than the rest, where the mixture is cooled at agitation to -3 - -5°C. After that, the mixture is abruptly cooled to -20 - -23.5 °C the solution deposits crystals of Si2Cl6 and VOCI3. The deposited crystals remain in the primary cooler, and the solution self-flows into the secondary coolers, where it is gradually cooled from -23 to -27 °C titanium tetrachloride deposits as white sediment. It is collected in the secondary coolers and washed with water. The TiCl4 thus purified is 99.92% pure. 

When the synthesis ends, as shown by pressure fall and constant temperature in the reactor, the valve between reactor 1 and cooler 4 opens, and ethyl mercaptan is distilled from the reactor. It self-flows into collector 6 through coolers 4 and 5. Collector 6 serves as a kind of settling box for tank residue. From there, ethyl mercaptan enters apparatus 7 and is pumped with immersed batching pump 8 into rectification tower 10. After ethyl mercaptan has been distilled, the tank residue in reactor 1 is cooled down after that, it is pressurised with nitrogen under 3 atmospheres into... 

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