Document jyDkpK5oq7n617qQML2Y8gXg9

`Trade name r*g. U. S. Pa*. Off. 1248 HONS OoOO^U ............................ has been used successfully since 1941 as a liquid phase heat transfer medium at atmospheric pressure and temperatures up to 600F. The compound, essentially tetrachlorobiphenvl, is a fire-resistant and non corrosive liquid, which does not crystallize at low temperatures. Handled properlv, in well-designed forced circulation heat exchangers which avoid localized over heating damage, the fluid gives satisfactorv continuous service for manv years without replacement. Most significant, Aroclor 1248 is practically non-flammable. In one in stallation of record, a ruptured pipe that spewed the hot fluid into gas flames failed to cause the fluid to ignite. For general heat transfer, Aroclor 1248 has several other important qualities: it is highly mobile and can be readilv pumped at temperatures as low as 5QCF. If cooling is necessary, the heat transfer fluid can be put through a water cooler to be used as a coolant. . . using this single fluid for both heating and cooling. Aroclor 1248 transfers heat (up to 600'F.) as a liquid. This liquid phase heat transfer makes it unnecessary to use the expensive pressurized equipment required bv a heat transfer medium that operates as a vapor. Aroclor 1248 operates safely and efficiently with gas-fired, oil-fired, or electrical heat sources. It is used successfully in the following types of applications ....  Chemical Processing Equipment, particularly for reacting flammable materials Cooking of Alkyd resins, varnishes, waxes Plastics molding, extruding, calendering Rubber processing Heatmg asphalt Food Processing, including potato chip and doughnut frying in vegetable oils Processing tftaraum, magnesium, other non-ferrous metals Fabrication of magnesium and aluminum honey-comb structures for aircraft Indirect beating in dyestuff manufacture Heating of corrugating rolls Indirect beating of distillation equipment Saponification of fats Calcining Ovens Impregnation and lamination of fibrous materials HONS 080030 Appearance Absolute density, g./ml. Absolute viscosity, centipoises Thermal Conductivity, Btu./hr.sq. ft/F./ft Spec. Volume, ml./g. Practically colorless meWe Iqud. Temperature Centigrade 'Fahrenheit 1.44 30 86 1.41 60 140 1.37 . 100 212 1.27 200 392 1.17 300 572 112.0 3C 86 17.5 60 140 4.2 100 212 0.99 200 392 0.47 300 572 0.0571 30 0.0564 60 0.0555 100 0.0534* 200 0.0512* 300 * Extrapolated Data. 86 140 212 392 572 0.696 0.709 0.728 0.787 0.860 Tabic 1 30 60 100 200 300 86 140 212 392 572 HONS 080031 (Table 1, cont.) Spec. Heat, cal. g. C. Vapor Pressure, mm. Hg. Distillation Range, ASTM D-20 flash Pt.. Cleveland Open Cup, ASTM D 92-45 fire Pt.. Cleveland Open Cup, ASTM, D 92-45 Pour Pt., ASTM, D-97 Average Coefficient of Expansion ce. a. 'F. 0.283 0.297 0.326 0.355 0.00037 0.16 2.9 18.0 350.0 Centifraile 50 100 200 300 37.8 100 150 200 300 345-385 "FatirwlMt 122 212 392 572 100 212 302 392 572 652-725 ___ 193-196 379-384 None 0.00037 0.00038 0.00041 0.00044 0.00047 0.00052 -7 -17.810 37.8 37.8 to 93.3 93.3 to 149 149 to 204 204 to 260 260 to 316 19.4 0 to 100 100 to 200 200 to 300 300 to 400 400 to 500 500 to 600 PHYSICAL CHARACTERISTICS of AROCLOR 1248 A complete knowledge of the physical characteristics of heat transfer media is highly essential to their satisfactory application in a heat exchanger. These physical constants have a major bearing on the equipment design, its mainte nance, and its operation. The following figure, and- chart, give basic physical data on Atoclor 1248. MQfvS QdOOdd DENSITY OF AROCLOR 1248 (Top im, b_/co. ft; bottom nk, gnt/ml.) DENSITY ft DENSITY gii./ml. HONS GtiGOii TEMPERATURE F. VISCOSITY UNITS VISCOSITY OF AROCLOR 1248 (Saybofe Unvcnal Swot) VISCOSITY, SAYBOLT UNIVERSAL SECONDS Figure 3 HONS 0tt0035 HEAT CAPACITY and Its Relationship to Density Systematic errors exist in the various accepted pro cedures for making specific heat determinations. Consequently values may vary depending upon the procedure used. In practical operation, it frequently appears that the values for Aroclor 1248 shown in Figure 4 arc somewhat low. Consequently, although these values have been accurately determined, they may be regarded as conservative. When comparing the specific heat values of Aroclor 1248 with corresponding values for other heat transfer fluids, it is important to note that the density of Aroclor 1248 is much higher relatively than the density of other liquids used for heat transfer. Accord ingly. when comparison of heat capacity is made on a volume basis (which Is most pertinent in equipment design and efficient operation) the heat capacity of Aroclor 1248 shows itself to better advantage than by direct comparison of specific heat values. Although specific heat values arc imfxjrtant, they represent only one of several important constants that enter into the equations for calculating over-all heat transfer efficiency. Through the use of these conservative heat capacity values, it is possible that equipment engi neered from such data might be slightly "over designed." It may be one of the factors that accounts for the exceptionally good operating performance of a number of highly successful commercial applications. MUhi 000036 SPECIFIC HEAT OF AROCLOR 1248 figure 4 HONS 06003? Temperature c. F. 0 32 10 50 38 100 66 150 93 200 121 250 149 300 177 350 204 400 232 450 260 500 288 550 316 600 HEAT CONTENT of Aroolor 1248 Specific Heat .269 .272 .280 .288 .295 .303 .311 .319 .327 .335 .343 .351 .359 Heat Content Btu./lb. 0.0 4.85 18.65 32.85 47.43 62.38 77.58 93.48 109.66 126.21 143.17 160.52 178.27 HONS 08003a THERMAL CONDUCTIVITY and VISCOSITY The thermal conductivity values of Aroclor 1248 are shown in figure 5. The curve shows this value over Aroclor 1248s opiating temperature range, from 50F. to 600F. As freshly charged into a heat exchanger, Aroclor 1248 has an initial viscosity of 74 (S.U.S.) at 130F. which corresponds to a viscosity of approxi mately 3000 (S.U.S.) at 50F. -- which temperature is assumed for practical purposes to be about the limit at which Aroclor 1248 can be conveniently pumped with a centrifugal pump. The following table shows a comparison of the initial viscosity and the viscosity after a year's con tinuous service at 600F. in a LaMont forced circu lation heater: TABLE III Appearance Specific Gravity, 56* C. Viscosity. S. U. S. at 130*F. Original Colorless Liquid 1.4M 74 0 After one Year of service at 60Q'F. Dark Brown Liquid 1.418 83.5 Although Aroclor 124S tends to darken in use, this darkening is not harmful and does not indicate decomposition. In actual use at Monsanto, it has not been found necessary to replace the fluid after seven years of continuous use; additional fluid is only added as necessary' to make up spills or leaks. In Figure 6, the horizontal line indicating vis cosity limit of pumpabilitv at 50F. shows that the rate of viscosity increase based on a year's continuous service should permit Aroclor 1248 to serve approxi mately four years before increased viscosity may inter fere with its pumpabilitv when cold. In practice. Aroclor 1248 has given satisfactory pumpabilitv for much longer periods. A simple S.U.S. viscosity deter mination by the ASTM-D-88 method can be used for periodic checks on the fluid. HONS 080039 li THERMAL CONDUCTIVITY OF AROCLOR IMS (Daorf oliM'n -llnlii imnnliliJ <tato) Figure 5 0-055 THERMAt CONDUCTIVITY. Btw./(Hr.) (Sq.Ft) ("F XFt) 0050 HONS GttG0<>G EXPECTED MINIMUM SERVICE LXFE IN A FORCED CIRCULATION HEATER VISCOSITY, SAYBOIT SECONDS. l 130"f. Figure 6 YEARS OF USE AT 6QQeF. MQNS 060041 13 STABILITY Aroclor 1248 is an extremely stable chemical com pound. Tests over long periods of time have shown that 600 F. is a safe maximum temperature for continuous operation in heaters that are properly designed and operated to eliminate intense, localized overheating. At this temperature the fluid is 52F. below the initial temperature of its boiling range, and consequently re* mains a liquid. Near its boiling point Aroclor 1248 tends to (U-hvdrohalogcuutc to a 'cry slight but measurable degree. It this occurs as a result of accidental over heating, the small amount of HC1 gas evolved tends to pass through the vent tank without harm to the equipment provided that the system is dry. Experimental observations using ideally-suited heat exchangers operating at a temperature of 650F. with imposed nitrogen pressures of 30 and 70 pig. showed that application of pressure did not prevent this small amount of thermal decomposition, which also occurs when the material is heated above 60CT F. at atmospheric pressure. When heated continuously at 630 F. under nitrogen pressure a gradual increase in the viscosity of the fluid occurs indicating that its service life would be limited to about 6 months to one year. Results of operating at 600'F., however, with out imposed nitrogen pressure indicate Aroclor 1248 can be heated continuously at this temperature for about 4 years before any viscosity increase could be expected to interfere with its pumpability at 50sF. which is slightly below normal room temperatures. Provision should be made to prevent water contamination of the system. If the system becomes contaminated with water, any HC1 liberated by local ized overheating may dissolve in the water film which will float on top of Aroclor 1248 in the expansion tank. The acidic solution thus formed can cause corrosion. It is recommended that moisture be eliminated from the expansion tank by installing a moisture trap or by sealing the tank and applying 15 to 30 psig. of nitrogen gas. With exception of the expansion tank, the system should l>e kept full of Aroclor 1248 at all times to pre vent formation of air pockets where moisture may condense when the system cools off between periods of operation. Many years of practical operating experience has shown that Aroclor 1248 is virtually non-corrosive to valves, piping, tanks, and jackets made of cast steel, steel, or stainless steel. In actual use. brass valves have been used satisfactorily. HONS SAFETY of OPERATION Aroclor 1248 can be considered a non-flammable liquid; no fire point is obtained by the Cleveland Open Cup method on heating to its boiling point (650F.). The spontaneous ignition temperature*2' is 1.299F. In actual use, the following reported accident in a heating system demonstrates the fire resistance of Aroclor 1248 and the freedom it offers from the hazard of fire propagation. An operator's failure to start the circulation pump when the gas heater was on resulted in excessive coil temperatures. The line containing Aroclor 1248 sagged into the fire chamber. A weld rup tured and Aroclor 1248 poured into the red-hot fire chamlx*r in contact with the flame. Dense smoke and fumes arose from the heater but there was no external fire. After the gas flame was cut off, the smoking stopped. Insurance authorities allow the use of Aroclor 1248 heaters in many locations with a minimum of protection. No fire walls are required to isolate the heaters. Aroclor 1248 has a low vapor pressure. In sys tems that employ a vented expansion tank, the loss due to evaporation is not measurable. If Aroclor 1248 in the expansion tank would reach a temperature of 266F., the vapor pressure of the fluid would be only 1 mm. of Hg. SAFETY OF HANDLING Aroclor 1248 is an inert, unreactive liquid. If it is spilled on the skin, there are no noticeable ill effects It is advisable, however, to wash the skin with soap and water after contact. A skin burn resulting from accidental contact with hot Aroclor 1248 should be treated in the normal manner for hot oil burns. Any liquid adhering to the burned area need not be removed immediately unless treatment of the burn demands it. If the bum must lie cleaned, soap and water or repeated washings with a \egetable oil (olive oil) may be used. The vapors emitted by Aroclor 1248 heated to elevated temperatures are injurious on prolonged exjxisure and should not be breathed. It is indicated that 2.0 mg. of Aroclor 1248 per cubic meter of air is the maximum safe amount permissable in workrooms. In commercial heat transfer installations, it is presumed that Aroclor 1248 will be used in a closed system free from leaks. Accordingly, their should be little or no opportunity for workers to come in contact with Aroclor 1248 vapors. MGNS 050043 & design features HEATER The most significant factor to remember when selecting or de signing a heat exchanger for Aroclor 1248 use is this: Aroclor 1248 transfers heat as a liquid, at the maximum recom mended temperature of 600F. for continuous operation, which is approxi mately 50F. below the boiling point. Consequently, Aroclor 1248 does not form vapor to accelerate convection circulation. Ordinary fire-tube or water-tube heaters which depend solely upon convection perform satisfactorily only at relatively low temperatures. When temperatures of 500-600F. are required, a forced circu lation type heater is recommended. A satisfactory type of heater design would consist of a specified number of tubes in parallel, properly orificed to provide a high velocity fluid flow of 8 to 10 feet per second. These should be spaced to permit uniform heat absorption throughout their entire length. A typical construction is shown in Figure 7. In its fabrication, the heater should be ASME Code all-welded construction, conforming to state and local ordinances. Tube joints, which in an ordinary steam heater would be the expanded type, must be sealwelded to prevent leakage. All connections larger than should be flanged connections, since ordinary threaded pipe connection is not suited for Aroclor 1248 service. Spiral-wound stainless steel and asbestos com bination is recommended for sealing joints and plugs. Drain valves should be installed at all low points on the heater and the \ alves must conform with ASME requirements for "blow down" valves. MQNS QdOtm Since a heater operating on Aroclor 1248 is completely filled with liquid, costly liquid-level controls and condensate return pipes, fittings, traps, etc. are completely eliminated. Heaters can be provided with any desired kind of firing. Portable and small size stationary are frequently electrically heated; larger units may be gas- or oil-fired. In installations where an open flame presents a fire hazard, to meet insurance requirements the heater may be installed in a separate build ing with piping carrying the hot Aroclor 1248 to the point of use. Properly constructed transmission pipes may extend for hundreds of feet. HEATER EFFICIENCY Forced circulation heaters with integral economizers will show an efficiency of from 75 to 80%. Heaters of the straight con nector type show efficiencies of 65 to 75%, depending upon the discharge temperatures. HEATER CAPACITIES Heaters using Aroclor 1248 (gas- or oil-fired) are available in output capacities ranging from approximately 250,000 Btu. per hour to large units rated over 10 million Btu. per hour. A heat flux density (or heat energy input) of approximately 5,000 Btu. per hour per square foot of tube surface is regarded as satisfactory. For lower output rate, electrically-heated units are favored, employing watt densities of 12 to 16 watts per square inch. I MQNS 0B0045 THE USERS Tbe '`asm" or retipicati of tbe heat at the post of pci be any type of heating pan, plates, jadseted kettle, or cods of stool or standees steel construction. Ordinary be piww construction is satiafactory, wee the pressure imposed an the Ancbr 1248 seldom exceeds 50 psif. In the user, however, it b important that afl-welded construction be used. Threaded connections may allow leakage of tbe hot fluid. As in the heater, all connections S' and over should be flanged and all joints sealed with spiral wound stainless steel and asbestos gasket material Alloy bolts should be used to secure flanges. A typical system with several usess is 18 THE PUMP For most systems, cast-steel centrifugal pumps with watercooled stuffing box and bearings are to be preferred. However, high temperature centrifugal pumps with mechanical seals are now available which give excellent performance. In some in stallations. immersion pumps have been used. Whatever type is selected, the pump capacity and pressure head must be sufficient to circulate the volume of fluid at the rate the particular installation demands. To avoid shaft trouble and leakage at the seals, it is important to provide adequate expansion joints and to support the piping in a manner to avoid stresses on the body of the pump. Direct-connection pumps driven by 1,750 rpm. motors are most commonly used. Each pump should be fitted with a positive differential control to switch off the burner in case of pump failure. When a new system is first put into operation, a slight leakage may be noticed at the pump. It is not advisable to tighten the pump gland, however, until the system has heated up close to the temperature of operation. PIPING LAYOUT The most important factors in the piping layout for Aroclor 1248 systems are (a) proper sizing for the required flow rate and (b) minimizing pressure drop. Because the sys tem will undergo temperature changes, adequate expansion joints and loops to relieve expansion and contraction stress are essential. All pipe lines and connections should be of extra heavy or Schedule 80 welded construction meeting A.S.M.E. require ments. Flanged joints should be used as sparingly as possible to minimize potential leak points. All valves and controls should be cast stcei construction with stainless steel seats. Pipe lines should be well insulated and those exposed to temperatures below 70'F. should be steam jacketed. All high points in the piping system should be provided with vent valves: all low points should have drain connections. Piping should be well anchored at frequent intervals, particu larly near expansion loops, to prevent vibrations. Figure 9 shows a typical piping diagram that illustrates the important features of an Aroclor 1248 piping system. These may be* varied to suit the installation. HONS 000047 19 THE EXPANSION TANK The expansion tank should be large enough to accom modate about 20% of the total volume of the entire system, including the fluid content of the heater, piping, and a!! heatusers. Tank should be sized to be V4-fuil when system is cooled to TO'F. and ^*-fuli when system is at maximum operating tem perature. Expansion tank should be fitted with a sight glass at the "full" range and a float-operated low-level switch to shut off burner in case of accidental fluid loss in the system. The expansion tank should be mounted on a platform high enough to support the liquid reservoir at least six feet higher than the highest point in the piping system. THE FEED and DRAIN PUMP To eliminate manual filling and draining of the heating svstein. it is leioiumemlrd that a small 2-to--5 gpm. positive displ.Kviu. nt pimiji !> installed at some convenient point to pump the Arnclor 1248 into or out of the system. CONTROLS Controls for heating systems using Aroclor 1248 should be installed both on the heater itself and on the heat-using units. A wide variety of thermo-operating controls are available and any reliable standard equipment is satisfactory. Heater controls should be installed to regulate the firing mechanism in direct proportion to the required output. These controls should increase or decrease the heat in-put to main tain the ArocIor 1248 at the operating temperature required by the heat-demand of the user. Small units mav lx? operated satisfactorily by relatively simple "on-off' or "high-low" con trollers; larger units may o[>erute more uniformlv if equipped with modulating temperature controls. User Controls should be installed to regulate the flow of the heat transfer fluid in direct proportion to the heat-con sumption of the heat-using equipment. In a multiple-user sys tem, separate controls should be installed on each consuming unit, to assure the proper heat-delivery. Safety Controls, in addition to activatin': controls, the heater must also be fitted with tire projrcr safety controls to meet the A.S.M.E. requirements. Safety controls should include: 1. A high temperature limit control operating at the heater outlet to shut olf tlr burner m the event of an e.vcessne temjieratHre rise. 2. A suitable low-limit temperature control to hold the burner at low fire until the Aroclor 124d in tire system reaches .v temperature level of I80*F. The low limit temperature control is essential !x*cause the viscosity of Aroclor 1248 is rather high at normal room tem perature. To avoid localized overheating upon start-up, it is not advisable to apply full heat from the burner until ail the fluid in the system has attained a viscosity that allows good flow and unimpeded circulation. Cold start-ups require slow up-heats. Burners should be equipped with automatic ignition controls and flame failure controls. In wide-range firing opera tions. an over-fire draft control will increase the economy of operation. Induced draft fans are another factor which should be considered as a means of avoiding the e\jx*n.se of high chirnnevs. Where they are needed throughout the svstein. go<xi quality recording or indicating gauges should be installed. COOLING EQUIPMENT Where fast reduction of temperature is required suitable, air- or water-cooling installations may be used. II the crxiler is to lx* a water-tv(X* unit, it is suggested that stainless steel tubing be used for the coils to avoid corrosion on the water side. If a cooler is installed in the svstein. low temperature limit con trols should also be installed to avoid excessive cooling that might raise the viscosity to the point of impeding the circulation in the system. HQNS oaoovb FILTERING EQUIPMENT When heating systems operated on Aroclor 1248 are run continuously near the maximum temperature of recommended operation (600*F.), it is advisable to provide a filtering device that can he attached to the drain line of the storage tank. In this way discrete particles of dirt that may get into the system can be filtered out periodically. This is an advisable maintenance step since it will eliminate the danger of dirt clogging the valve seats or lodging in parts of the control mechanisms. A small portable filter such as those manufactured by Honan-Crane Corporation (Lebanon, Ind.) or Sparkler Manufac turing Company (Mundelein, 111.) is quite satisfactory. CONNECTIONS and GASKETS in a system operated on Aroclor 1248, welded connec tions are preferable; threaded screw connections should be avoided wherever possible. This precaution will minimize leaks with consequent make-up. All connections 1" and over should be of the flanged type fastened with alloy bolts to prevent frozen connections. Steel connectors should be used for all instruments and controls. For gasketing, spiral wound gaskets of corrugated stainless steel and asbestos combination should be used on all flanged connections. TESTING and CLEANING THE SYSTEM When a new system has been installed, it is essential to test the entire system hydrostatically for leaks, and to wash out ail the lines to remove dirt, oil films, or pipe scale. Both the cleaning and the testing can be done with a single operation, such as the following: Fill the entire system with a water solution containing 5 pounds of soda ash and 5 pounds of caustic soda for every 1000 pounds (120 gal.) of water used. Thoroughly vent the sys tem at all of the highest points in the piping system to assure complete filling . . . then start the circulating pump. With the pump running, the entire system is next inspected for leaks. Next, turn on the burner at low-fire rate and raise the temperature of the wash solution to 1S0;F. This hot wash solu tion should be circulated continuously through the entire system (heater and all users) for at least 24 hours. At regular intervals a portion of the solution should be drained and replaced by fresh water. This partial draining should be continued at regular in tervals until the drainage from the system is clear. At the end of the 24 hour period, tire temperature of the circulating wash solution should be brought up to 240'F. and the fire turned off. The whole system should then he drained and all vents in the piping opened. Residual heat will dry the pipes and the heater through the vents, which should remain open until inspection shows that the system is entirely dry. When all traces of water have dried out. the drains and vents are closed. Aroclor 1248 is then charged into the cleaned, dry sys tem. The circulating pump is started and firing begun at low heat until the Aroclor 1248 has reached a temperature of 2-505F. Periodically during this initial up-heating, the lines should be vented every 10-15 minutes for at least two hours to allow any residual moisture or air to escape After it is certain that all moisture has been eliminated from the system, the entire system should be inspected for leaks with the pmnp circulating the hot fluid. As a final inspection, the expansion tank should be checked to make sure that the tank is V* full. After this, the burner can be set to full-fire and the system brought up to operating tem perature. When the temperature of operation has been reached all controls should be checked and adjusted so that the burner is regulated for full modulation. When the system is brought to full operating temperature, all pipe lines should be given a final inspection for expansion and bracing. MQNS 060049 GENERAL RECOMMENDATIONS for Operation and Maintenance The following recommendations are primarily guides for the manner of using Aroclor 1248 in an operating system. They are supplemental to the equipment manufacturer's own recommendations for operation and maintenance that relate to the heaters or the heat-using installations themselves. The recommendations for start-up, shut-down, precautions in event of power failure, and periodic check-ups on the fluid and equip ment apply as generally accepted practice on all types and sizes of systems. By following these recommendations, the troublefree service life of the heat transfer fluid will be increased. START-UP When systems have been shut down for week-ends or over-night and the fluid is cooled to room temperature, follow this start-up procedure: 1. Start the circulating pump and check the expansion tank to make certain the Aroclor 1248 is at the proper cold-start level (Tank should be Vii-full.) 2. Start burner at minimum flame setting and continue full circulation until Aroclor 1248 is heated to 180'F. when measured on the return skit- of tin* heater. 3. Turn heater up to full heat. SHUT-DOWN The following procedure will eliminate overheating of the fluid when shutting down: 1. Shut off burner completely with circulating pump still oper ating. Continue to run the* circulating pump at full head for at least 14 hour to dissipate high residual heat in the com bustion chamber of the burner. 2. Shut off circulating pump at the end of Vi hour and switch off all heater electrical controls PRECAUTIONS IN COLD WEATHER When heat exchanger is exposed to ambient tempera tures below 505F.. it is recommended that unit not be shut down, ft is recommended that the burner Ik* turned low arid the fluid circulated continuously at about 200;F. The unit will then be "at ready" for immediate high temperature operation. PRECAUTIONS IN CASE OF POWER FAILURE In case of power failure, the burner circuit is interrupted by the heater controls. When power comes on. the circulating pump should first be run for a few minutes to eliminate any vapor pockets that might have been formed by the fluid's being held static in the hot combustion chamber. If there is no knock ing in the piping system, full-fire may be resumed immediately. PERIODIC CHECK-UPS The regular maintenance inspection schedule should include the equipment manufacturers recommendations and also inspection of the heat transfer fluid. The following is a listing of check points. 1. Lubrication of moving parts. 2. Operating fidelity and accuracy of readings of safety controls and temperature limit controls. 3. Inspection of heater tubes, burner, refractory linings. 4. Periodic cleaning of beater surfaces. 5. Inspection of water cording at the circulating pump. 6. Regular repacking of stuffing boxes according to the manu facturer s recommendations. 7. Semi-annual or annual sampling and analysis of Aroclor 1248. Under normal operating conditions not affected by fre quent power failures or accidental overheating, when Aroclor 1248 is operated at 6005F. it should not be necessary to check on tile condition of the fluid more often than once or twice a year. The analysis for fluid condition is a simple determina tion of viscosity. The information given in Figure 6 serves as a guide to estimate the condition of the fluid, according to vis cosity values. Most users do their own testing; some have the viscosity determination made by an outside laboratory. Customers can have their fluid tested by Monsanto free of charge. A one-quart sample is required, and sample should be carefully packed to avoid breakage in shipment. Samples should be shipped to: Monsanto Chemical Cornpam Organic Chemical Division Industrial Fluid Sales St. Louis. Missouri HONS 080050 22 engineering data Designing or purchasing equipment for a heating system to be operated with Aroclor as a medium to deliver heat into a process requires consideration of heat transfer characteristics of both the user and the heater. The actual heat which can be absorbed by a user, for example, depends upon the over-all heat transfer coefficient, heat transfer area, and a mean tem perature difference between Aroclor and the material being heated. Both overall heat transfer coefficient and mean temperature difference are. in turn, affected by the flow rate of the Aroclor. This inter-relation of flow rate, heat, and temperature is usually solved by a trial and en-or procedure as covered in standard reference texts. The approach of Craneto may be used to minimize or eliminate trial and error. The following tables and graphs of physical properties and engi neering data are provided as an aid in layout and design calculations for systems to be operated with Aroclor 1248 as a heat transfer fluid in the liquid phase. Table IV lists properties useful in heat balance calculations by which the flow rate is related to the heat transferred and the temperature change of the Aroclor. This relation is also shown graphically in Figure 10. The over-all heat transfer coefficient for the heater or user may be estimated by the methods outlined in the texts of McAdams^ or Kerno. This is usually done by combining the individual film coefficient of the Aroclor with other coefficients and conductivities to yield the over-all coefficient. Table V contains physical properties of Aroclor as a function of temperature which are needed for calculating the Aroclor film coefficient. Tables VI gives typical film coefficients for Aroclor flowing through a 0.81 inch i.d. tube. These are listed as a function of temperature and flow rate in a tubular heat exchanger. Other tube sizes would, of course, require a correction for the diameter in the Reynolds and Nusselt group of the equation (from McAdams) given at the top of Table VI. Correlations for estimating film coefficients for various material that might be processed by indirect heating may be found in the texts 4 and 5 cited and elsewhere in the literature. For sizing pipe lines and pumping requirements. Figure 11 shows pressure drop vs. flow rate and pipe size for Aroclor 1248 at temperatures over 300F. Above this temperature Aroclor 1248 flows freely like water. HONS 030051 \ f Tomptroluro *C 3? 0 40 4 SO 10 60 16 70 21 80 27 90 32 100 38 no 43 170 49 130 54 140 60 ISO 66 1(0 71 170 77 IN 82 190 88 NO 93 210 99 220 104 230 no 240 116 2S0 121 200 127 270 132 ?N 138 ?90 143 300 149 310 154 3?0 160 330 166 340 m 350 177 360 182 370 188 380 )93 390 199 400 204 410 2)0 420 216 430 221 440 277 450 232 460 238 470 243 480 249 490 254 500 260 5)0 266 S?0 27| 530 277 540 282 550 788 500 293 570 299 580 304 590 310 600 316 610 321 620 327 630 332 Titbit* A THERMODYNAMIC PROPERTIES OF IROCIOR No. 1248 TABLE IV tnlhplpy _ p Oantilp (Spc. *#)> Ibt./ci. II. Ibs./ial. *f. __ ________ __ SpK'Fx OfAvily ADtetkl* VCitKnOlipiitmy mIN 0 000 2.162 4.881 7.616 10.367 13134 15.917 18.716 21.S3] 24.362 27 709 30 072 32.951 35 846 38757 11.784 44727 47.686 50.661 53.651 56.667 59.679 62717 65771 68.841 71.927 74.029 77.147 90.28! 83431 86.597 89779 92.977 96.191 99.421 102.667 105.929 109.206 112.499 115.808 119.133 122.474 125.831 129.204 132.593 135.998 139.4)9 142.856 146309 149778 153.26? 156-762 160 278 163.810 167.358 170 97? 174.50? 178.098 )81 710 185 338 188.98? 0.2695 0.2711 0.2727 0.2743 0.2759 0.2775 0.2791 0.2807 0.2823 0.2839 0.285$ 07871 07887 0.2903 07919 0.2935 07951 0.2967 0.2982 07998 0.3014 0.3030 0.3046 0 3062 0.3078 0.3094 0.3110 0.3126 0314? 0.3158 0.3174 0.3190 0 3206 0.327? 0 3238 0.3254 03269 0.3285 0 3301 0.3317 0.333) 0 3349 0.3365 0.3381 0 3397 0.3413 0 3479 0.3445 0.3461 0.3476 0 3492 Q.3S08 0.3524 0.3540 0.3556 0.3572 0.3588 0 3604 0.3620 0.3636 0.365? 91.6 913 909 90.6 907 89.8 89.5 89.1 88.8 88.4 86.1 878 87.4 87.0 86.6 86.2 85.9 85.6 857 848 84.4 84.1 837 83.4 831 82.9 82.6 82.3 81 9 816 81.2 90.9 80.6 807 79. B 79.4 79 1 788 78.5 787 77.9 77.6 777 76. B 764 76.1 75.7 75.4 75.0 74.7 74.4 74 ! 73.7 73.4 730 72.7 724 72.0 71.7 71.4 7) 0 1272 17.19 12.13 12.08 12.03 12.00 11.96 11.91 11.87 11.82 1177 11.73 11.69 11.64 11.58 11.53 11.47 11.42 11.38 11 34 11.29 1)74 31.38 1114 11.10 1)06 1103 1098 10.94 1090 1085 10.81 10.76 10.71 1D.67 1062 10.57 10.53 10.48 10.43 1039 10.34 10.30 1075 1070 10.16 1011 10.06 10.0? 9.98 994 9.90 9.85 9.80 9.76 971 9.67 963 9.58 953 9.48 1.47 1.46 1.455 1.45 1.445 1.40 1 432 1.425 1.420 1414 1 409 1.404 1.400 1.493 1.387 1.38! 1.375 1.370 1365 1.359 1.353 1.348 1.342 1.336 1.331 1.326 1.321 1.316 1311 1 305 1300 1.296 1 291 1.286 1280 1.274 1769 1764 1.259 1753 1748 1743 1 237 1731 l ??$ 1720 1 214 1 208 1702 1 196 1.191 1 186 1180 I 175 1.170 1.165 i 160 1.155 1 150 1 144 1.138 850 380 200 115 66 47 32 24 18 14 11 91 7.5 63 52 44 39 335 3.00 2.68 2.38 208 196 1 82 1.68 1.58 1 46 142 130 172 1 15 1.10 105 1.00 0.96 091 0.87 0.84 080 0 76 0 73 0 71 068 0 65 061 060 057 0 55 0.53 051 0 49 0 47 0 45 0.43 042 0 40 0 39 0.37 HUtiS caoos^ FLOW RATES FOR AROCLOR *1248 TEMPERATURE DIFFERENTIAL BF OF AROCLOR ENTERING ANO LEAVING THE USER Figure 10 FLOW RATE GALS. PER MIN. HONS 080053 TtmOOTtsra C. THERMODYNAMIC PROPERTIES of AROCLOR 1248 VtWM*| Lta. "Sr RT~ Ttcmd CiwilintiwfT ~ ta ft. Mr."*#: k P IA NDTl {VT LkJ f. MhMi Therm*! Vacswty CaMcctmtf c. Ita. 0t. 32 0 0.0577 40 4 .0576 SO 10 60 16 2060 70 21 960 Q37S .0574 .0573 9844 4430 39.5 28.7 80 27 48S 90 32 278 100 38 160 0572 .0570 .0569 2353 1361 789 223 17.9 14.4 110 43 114 .0568 566 120 49 77.5 3566 388 12.6 10.8 130 54 58.0 .0565 293 140 60 43.5 .0564 221 9.7 8.7 ISO 66 33.8 0563 173 7.88 160 71 26.6 .0562 137 7.15 170 77 22.0 0560 115 6.68 180 82 18.2 .0559 95 6.18 190 88 15.2 .0558 80 5.78 200 93 12.6 .0557 67 5.38 210 99 10.6 .0555 57 5.05 220 104 9.45 .0554 SU 4.83 230 110 8.10 .0553 44.1 4.55 240 116 7.26 .0552 39.8 4.36 250 121 6.48 .0550 35.9 4.18 260 127 5.76 .0549 32.1 4.00 270 132 503 .0548 28.2 3.81 280 138 4.75 .0547 26.8 3.73 290 143 4.40 0546 25.1 3.63 300 149 407 .0544 23.4 3.53 310 154 3.83 .0543 22.2 3.45 320 160 330 166 340 171 350 177 360 182 370 188 380 193 390 199 400 204 410 210 420 216 430 221 440 227 450 232 460 238 470 243 480 249 490 254 500 260 510 266 520 271 530 277 540 2S2 550 288 560 293 570 299 580 304 590 310 600 316 153 .0542 334 3541 3.14 .0540 2.95 .0539 2.78 .0537 2.66 .0536 234 .0535 2.42 .0534 2.32 0532 2.20 .0531 2.10 .0530 2.03 .0529 1.93 .0527 1.83 .0526 1.76 .0525 1.71 .0524 1.64 .0523 1.57 .0521 1.51 .0520 1.45 .0519 i 38 0518 1.33 .0516 1.28 0515 132 0514 1 18 .0513 1.13 0512 1.09 .0510 1.04 3509 1.01 3508 Tabic 5 k 20.6 19.6 18.5 17.5 16.7 16.1 15.4 148 14.3 13.7 13.1 12.7 12.3 11.7 11.3 11.0 10.7 10.3 10.0 9.67 9.26 9.00 8.72 8.36 5.14 785 763 7.33 7.16 M 335 329 322 3.15 3.08 3.04 2.99 2.94 2.90 255 2.50 2.76 2.73 2.68 2.64 2.61 2.58 254 2.51 246 2.43 2.40 2.37 2.34 2.31 228 2.25 2.22 2.20 HONS 1)80054 T *F. 150 200 250 300 350 400 450 500 550 600 Table 6 HEAT TRANSFER DATA for AHOCLOR 1248 (FILM COEFFICIENT) ri2 n ro (H o* re**] 9.4 li LotiJ^ ^l^j ltj McAdams; lasal aa Saw tSrMtS U1` I. 0.trta(1' 0. D. lUp.) aiflrtuad ia Mk/ss. ft. Sr. *F. FLOW ATE 6PM nr1.0 2.0 3.0 4.0 5.0 6.0 u 83.2 86.2 93.8 44.9 63.4 78 7 94.0 109 124 138 33.5 58.5 80.9 102 122 141 159 177 40.5 70.1 97 122 146 169 191 212 45.3 79.0 109 137 164 190 215 239 49.0 85.5 118 149 178 206 232 259 53.3 93 128 162 193 224 253 282 56.3 98 136 171 204 236 267 297 605 105 145 183 219 253 286 319 64.2 112 155 195 233 269 305 339 9.0 103 151 195 233 262 284 309 327 350 373 10.0 114 164 212 254 286 309 336 356 381 405 Cakuiattu* (w rtfati MM sum eaa S audt using tbs lata faaatf ia TaMas IV art V. Na Alai caaAciawb wara cateWaM far flaw rain wfctra tha laynails auabar was lass ttun 21M. 11.9 123 179 229 274 309 334 363 383 411 431 12.0 130 191 245 294 331 358 388 411 441 469 HQNS 08003d Z7 FRICTION LOSSES IN SYSTEM FIFING AROCLOR 1248, ABOVE 3003F. HEAD LOSS, FT. PER 100 FT. 100,000 figure 11 HONS 080056 A 200,000 Btu. (right) and a 300,000 Btu. beater both gas-fired, have been m use at Monsanto for over 14 years for organic chem icals reactions. The heaters have operated near 600F with the same charge of Arodor 12*8 for periods of 7 years. HONS 060057 29 (0I>MI) A steam iaM ki leading t* a *tm coil . invoa tM wscnaf lof kaatwgcotd Aiodo*. Arodor Hatt: The heater conasR <rf bfck ^ *ai,s ,nfl bcttm made a Seel shell itli seel bailies lo terce the hot cornbustron cases tor three aesses aver lire brador coil. The tr is a steel Male left side atai nM Twa.jja* shell and lube corrslriretioe enth the Arodre 12AI or the outside ol the tubes. The two slage cooler is Ml*d so that one stage an I* used on each Arodor beater or both stages can be used on eilhet Arodor healer HONS 080058 A 40.000 Btu. per `war electrically heated portable heat exchanger used to heat vessels of about SO galloes working capac ity. This unit was built for $ variety of snail scale chemical reactions. It was initially designed to vaporize approxi mately 200 lbs./hr. of an organic com pound which has a heat of vaporization of ISO Btu. per pound; a 30% heat loss was slowed for. Experience with the heater indicates that a horizontal rather than the vertical mounting of the immer sion heater (at operator's left) would have been more satisfactory. A 4,000.000 8tu./hr. forced circulation International LaMont heater. Control panel for a 3,000,000 Btu./hr. International LaMont heater that oper ates the 3,500 gallon, glass-lined kettle shown or the left This kettle is the largest of its kind in (he United States. Commercial heaters operating on Arcelor 1248 are available in any capacity desired. This is a 1.200.000 Btu./hr. installation. 1 MQM& O0OO59 4 I 32 A pilot plant resin processing vessel operated on indirect heat transferred by Arodor 1248. Vessel and- heater are mounted together in one unit This 500,000 Btu./hr. forced orculation heater is electrically heated and designed `or a liquid temperature of 5O0F. The construction is similar to a double pipe heat exchanger with the electric heating elements in the inner pipe; the Arodor 1248 circulates through the annular space between inner and outer pipe. The liquid Arodor 1248 is delivered from the heatei at a temperature of SOO'f. and heats the conteals of a jacketed kettle with a batch capacity of 1,000 gallons. This design for a forced arcutation heater was de veloped by Cleaver Brooks Company. UTKUATl'KK C ITI.l) 1. Monsanto Chemical Co., St. Louis, Mo., Application Data Bulletin 0-115 (1954). 2. Sullivan, M V., Wolfe, j. K-, and Zisman. W. A "Indus. Eng. Chem.,' 39, 1607 (194i i. 3 Cranet, II, "Heat Transfer Performance Curves", Chemical Engineering, P. 1ST-190. March, 1955. 4. McAdams, W. H . "Heat Transmission". McGraw-Hill Book Co., Inc., New York, (1942). 5. Kern, D. Q . "Process Heat Transfer", McGraw-Hill Book Co.. Inc., New York. (1950). HONS 080060 / liquid heat transfer fluid Temperatures up to 600F. Long-lasting, trouble-free service Fire-resistant, non-corrosive Operates in un-pressured, minimum cost equipment Momsamto supplies Aroelor 124S, but mot tko hoot oxckamgtn. Momsamto trill bo to rtcowwnid mhitm of supply. HONS 060061 M HONS 080062