LIQUID;- METAL CAVIT ATION EROSION RESEARCH INVES T IGATION FOR NATIONAL ADVISORY COMMITTEE3 FOR AERONAUTIC S Pro;gress' Report No, 1 UtRI. Pro j ec t. 2824. November 1, 1958 F, G. HIammitt E. Mo Brower Project Supervisor F. G. Hammitt

TABLE OF CONTENTS Page 1.0 Introduction --------------------------------- 1 2.0 General Objectives -------—. —-------—. —--- 1 3.0 Research Program -------------------------- 1 3.1 Water Phase -................ 1 3.1.1 Objectives -------------------—. —- 2 3.1.2 Equipment to be Utilized ------------- 2 3.2 Mercury Phase......... —------- -I —----- 2 3.2.1 Objectives ----—. ----------------- 2 3.2.2 Equipment to be Utilized ----— ~ — 3 3.3 Lead-Bismuth Eutectic or Bismuth Phase ---- 3 3.3.1 ObJectives --------------- 3 3.3.2 Equipment Required -------- 3 3.4 NaK Phase —.... _._.__............. 3 3.5 Further Phases --— 4-. —-- 4 3.6 Projected Time Schedule --- ----- 4 4.0 Component Specification 4 —-~~ —- ~. —-- 4 4.1 General S i zing -—. —-- aa........... — - 5 5.0 Overall Heat Balance -—. —-----.. —-- 5 5.1 General —.....__._._- 5 5.2 Mercury -..-. —-- 6 5.3 Lead-Bismuth Eutectic -----—..- 6 5.4 NaK and Water ------ -.. 7 5.5 Bismuth and Sodium --------------- 7 6.0 Pressure Loss ---- -. —... —------ 8 7.0 Appendix -21 7.1 Calculations of Cooler for Mercury Loop Side —- 21 7.2 Heating Circuits for Pb-Bi Eutectic ------- 21 7.3 Heat Loss in Spray Cooler -------. —-- 23

LIST OF TABLES Table Page 1 Pipe Sizing ------- ----------- _ —-... 5 2 Heat Requirements -.-.......... 5 3 Head Loss for Mercury Flow Through Loop ---- 10 4 Head Loss for NaK Flow Through Loop ------- 11 LIST OF FIGURES Figure Page 1 Sketch of Cavitation Loop Layout -------—. 12 2 Heat Requirements of Various Liquid Metals - 13 3 Pump Requirements for Various Liquid Metals as a Function of Capacity -— ~ —- 1LL 4 Heat Losses in Mercury Loop.. —--—. 15 5 Heat Loss of Insulated Pipe and Pump ----- 16 6 Heat Loss in Spray Cooler -------------- 17 7 Loop and Pump Characteristics for Mercury -- 18 8 Loop and Pump Characteristics for NaK ----- 19 9 Pipe and Test Section Velocity ---- 20

J1.0 Introduction A facility for the investigation of cavitation and erosion with fluids other than water generally, but with primary emphasis on liquid metals, is to be designed, constructed, and operated. As specified in the contract proposal and as described in detail in reference 1, the facility is to be a continuous flow tunnel with cavitating velituri, powered by a centrifugal pump. The basic objectives of the project and the anticipated research program are discussed in the next sections. These lead directly to the specification of the research equipment. The results of initial studies to determine suitable basic components are described in the following sections. The instrumentation details will be examined in later reports. The program is outlined over a period of several years and the anticipated progress during the present contract period of one year stated. 2.0 General Objectives The basic project objectives are the following: 1.) Determine those combinations of velocity, theoretical underpressure*t, change of pressure with respect to time and axial distance, temperature, and container material which are permissible from the viewpoint of avoiding prohibitive wear with different liquid metals of interest. Such data could be used as a guide in producing optimum pump designs. 24.) Study the nature of wear or pitting as affected by temperature, material, fluid properties, underpressure", rate of pressure change, and other applicable parameters which may become apparent. Fluid properties of interest include at least surface tension, density, viscosity, latent heat of vaporization, and freedom from impurities, solid and gaseous. 3.) Develop methods for determining cavitation effects on pump impellers with liquid metals through water-testing of models. 4.) Study basic mechanism of cavitation process with water and liquid metals. 3.0 Rese arc Pro ram As presently planned, the research program will follow roughly the phases outlined in the following sections. *:- Throat pressure which would exist in the absense of cavitation.

Page 2 3 o.1 lObjec tives 1o) Check out general performance of loop and instrumentation equipment~ Find ~Ip vs Q characteristics of test section wi'thout cavitation 2.) Determine general appearance of cavitation as a function of cavitation number. Correlate this with sonic pattern and other indications of cavitation which may be available, Examine effect of velocity magnitude for a given cavitation number. 3.) Obtain wear results on transparent test sections as a function of cavitation number and velocity. 4b.) Investigate scale effect; ie: try different size test sections for given cavitation number and velocity. 5.) Investigate effect of de-aerating water as far as possible to see if cavitation is suppressed. 6.) Check sonic pattern and other indications with steel test section under known cavitation number and velocity and compare with transparent section. j.1.2 Equipment to be Utilized 1.) Continuous flow tunnel with water-cooled cooler. 2.) Transparent and steel venturi test sections of various sizies 3.) Sonic and/or radioactive absorption equipment. 4-) Throat pressure measurement,.32 Msercury_ Phase L3 2.1 Objectives 1o) Compare visual appearance of cavitation of a liquid metal and water under same cavitation number, velocity, and rate of pressure change. 2.) Compare sonic and radioactive absorption effects under above conditions. 3.) Compare wear effects with water and Hg under otherwise similar conditions. 4.) Investigate possible effect of dissolved gas. 5.) Compare wear acnd sonic effects with plexiglass or pyrex and steel.

Page 3 6.) Investigate relation between wear and velocity and rate of pressure change with same cavitation number. Include zero cavitation (ie: pure erosion) o 7o) Investigate scale and rate of pressure change effects upon degree of cavitation. 8o) Investigate feasibility of wear detection with radioactive tracers. 3o2.2 Equipment to be Utilized The equipment to be utilized is the same as for the water tests with the possible addition of material to allow radioactive tracer wear detection. 3.3 Lead-Bismuth Eutectic or Bismuth Phase 3.3.1 Objectives 1.) Compare wear effects on various materials with a given liquid at fixed velocity, rate of pressure change, and cavitation number at different temperatures. Compare with effects obtained with water. Compare with pure erosion. 2.) Establish limiting conditions of rate of pressure change, cavitation number, velocity and temperature for pump design with lead-bismuth and different structural materials of interest. 3.) Compare apparent "degrees" of cavitation with water and mercury through sonic effects and radioactive absorption ability at given cavitation number, rate of pressure change and velocity. 303.2 Equipment Required lo) Continuous flow tunnel with spray cooler and heating coilso 20) Metallic test sections as required. 3.) Sonic and radioactive absorption equipment. 4L[) Throat pressure measurement @ 1000 F. with Hg. 5.) Temperature measuring instrumentation. 6.) Radioactive tracer equipment for wear detection. 3. _NaK Phase Objectives and equipment requirements are as above.

Page 4 3.5 Further Phases Additional research of application to liquid propellant rocket engines might be contemplated with such fluids as WFNA, JP-4, etc. The equipment is planned with sufficient flexability so that only moderations would be required. 3.6 Projected Time Schedule The total program outlined in sections 3,1 to 3.5 above would require perhaps three to four years to complete. It is estimated that a major portion of the work outlined under 3.1 Water Phase and some of that outlined under 302 Mercury Phase, can be completed during the present contract period of one year. 4,0 Component Specification As described in Reference 19 the facility is a continuous flow loop powered by a sump-type centrifugal pump and incorporating a venturi test section to create cavitationo Pump suction is held at approximately atmospheric pressure to avoid sealing difficulties. Two throttling values, upstream and downstream of test section respectively, are included to vary test pressure and velocity maintaining the desired absolute pressure in the throat. A venturi flow meter is included to measure flowo, A further controllable variable is pump speed. To meet the project objectives of delineating flow conditions suitable for large-scale liquid metal pump operation with respect to cavitation-erosion wear it is necessary to attain velocities and temperatures with the applicable fluids and structural meterials comparable to those expected in the full scale pumps. As a result of the work reported in References 1 and 2, it is believed that a velocity of about 50 ft/sec with the heavy metals as leadbismuth or 100 ft/sec with the lighter fluids as NaK will suffice. Also operating temperatures up to 10000F. should be obtainable. It is necessary that a test section diameter large enough for instrumentation, observation, accurate fabrication, and suitable Reynold s Number be provided. To investigate possible scale effects it is necessary that different diameter test sections be providedo As explained in Reference 1, it is felt that a nominal diameter of about w inch be used with the possibility of 4 inch and 1 inch sections for specialized testso The equipment then would be designed on the basis of attaining the maximum operating conditions in the 2 inch test section0 Figure 1 shows the proposed layout of the facility0 The pump, manufactured by the Berkeley Pump Company, is capable of pumping molten bismuth, lead-bismuth, or mercury at 40 gpm and a 45 ft. head at a pump speed of 1800 rpm and temperatures of 1000~F0 It appears feasible and desirable to pump lighter fluids (such as water and/or NaK) at 3600 rpmo

Page 5 Lo! General Sizing Preliminary calculations of the pressure drop to be expected for the system as a function of pipe diameter gave the following results: TABLE I Nominal Flow Pump Pipe AH loss % of pump Pipe Dia. Rate Head Velocity (loop piping) head (inches) ft) __(fps) (ft) I 40 45 14.9 17.5 38.0 J1 40 45 8.6 4e4 9.8 21 40 45 6.32 2.02 4.4 This was based on the design flow rate of mercury or leadbismuth for the Berkeley pump Schedule 40 pipe was considered in all cases since it appears adequate for the expected pressures. Based on these results, 1"t schedule 40 pipe was chosen to prevent excessive piping friction loss. Price estimates were obtained for all pipe size possibilities in schedules 40 and 80. Of the sizes considered, all schedule 40's were in the same approximate range, however, schedule 80's were about double the price. 5.0 Overall Heat Balance 5.1 General In designing a facility such as this, with the desired flexibility to handle several liquid metals and perhaps other corrosive fluids some design features required uy a specific fluid are necessary while in other cases a compromise is the most practical solution. Since mercury, bismuth, and lead-bismuth are all heavy metals, the major difference is in the melting temperature and hence the required heat input. Sodium and NaK are both lighter fluids and so have different pumping characteristics than the heavier fluids. Tabulated below are melting points and heating requirements for these fluids: TABLE II Heat Input Req'd Max. Fluid Melting Point to melt to h.j~. tem Temp -...0... eM —- Mercury -37o97 OF 1425 Btu 1500F Bismuth 520 6450 Btu 6050 1000 Pb-Bi eutectic 257 3180 12,450 1000 Sodium 208 2200 9170 1000 NaK 66.2 8360 1000

Page 6 It is apparent that no preheating is needed for mercury or NaK, but that-it is required for the other fluidso The heat required to bring the liquid metal and structure up to temperature, assuming no losses is shown as a function of the temperature in Figure 2. Mercurys lead-bismuth, and NaK are discussed separately as being indicative of the fluids presently considered for test. 5.2_ Mercuar Mercu ry does not require preheating and the heat input to attain operating temperature 1530F) is reduced from the total requirement by the amotrnt of the puimp work (Figure 3). Under maximuwm conditions the pump would supply 50000 Btu/hr while at a minimum (approximately 2 hp with mercury) it would supply 5000 Btu/hr0 Under the worst conditions, minimum flow rate and maximum desired temperature increase (from 700F to 1500F) 22 minutes would be required to heat the mercury using pnmp work only. Since this is not an intolerable warm up time9 no additional heat input is needed for me rrerory beyond that of the pump. In fact9 the major problem becomes one of providing sufficient cooling capacity to maintain operation at 1500F and full pump power. Calculations shown in detail in the Appendix indicate that a counter-flow type water cooler, 7 feet long9 consisting of stainless steel tubing containirng the liquid metal and surrounded by a large pipe containing water, will suffice at the maximum conditions. Stainless steel tubing is used rather than a pipe to reduce the wall thickness, which accounts for a major portion of the temperature differential (L-7/8" BTnWG 21 tubing9 wall thickness 0.032"). Figure 4 presents the total capacity of the cooler assuming 70 OF cooling water and the losses to the atmosphere of the remainder of the loop and pump, which need not be insulated due to the low maximum temperature (1500F), as a function of fluid temperature. 5.3 Lead-Blsmuth Eutectic The leadhbismuth eutectic will have to be heated from room temperature (700F) to about 3000 F in the dump tank to melt it and allow transfer to the pump0, This will require 3180 Btu for the Pb-Bi plus 2400 Btu for the tank which is equivalent to 1Q6 kw hro With a wrapping of resistance wire (220 v, 3 circuits @ 2o6 kw/circuit) this can be accomplished in 13 minutes (see Appendix for detailed calculations). Also the loop must be preheated to 3000Fo Using 2 resistance circuits, this requires 7 minutes o The sump tank must also be brought up to temperature before operation is commenced. With 4. resistance circuits on the tank only 5 minutes is needed to heat it from room temperature to 300~F. Thus, in the 13 minutes that the dump tank and full load of Pb-Bi are preheating, both loop and sump tank will also reach the required temperature. Hence t here is no time delay beyond the 13 minutes. Once the molten PbBBi is in the sump an additional 30 minutes is required to heat the sump and full load of fluid to 1000~F.

Page 7 Approximately the same time is required to heat the loopo If the fluid is being pumped around the circuit during this period the elapsed time will be reduced depending upon the pump speed and the valve positions. However, with no assistance from the pump and a heating circuit as described, it will take about 45 minutes to bring the system from a shut down condition at room temperature to 1000 F. The required electrical input will be about 25 kw, allowing 1 kw for loss to ambient (Figure 5). The distribution of 220 v, 2.6 kw circuits is as follows: 3 on dump tank, 2 on loop, 4 on sump. At temperatures above about 3000F it will be necessary to insulate the system as a safety precaution for the personnel. Hence, the heat loss to the atmosphere will be very little, and a cooler will be required to remove pump work at least at high head and flowo The loss through the insulated piping and pump to atmosphere is given in Figure 5o With the insulation described in Figure 5 the maximum temperature of the outer surface of the insulation is 1700Fo The maximum amount of heat to be removed will occur at full flow rate and pressure for low temperature testso Considering only the input of the pump work and the losses to piping and pump, approximately 33,000 Btu/hr, must be taken out by the cooler at maximum flow and about 6000Fo (see Figure 6). The heat load is not particularly sensitive to fluid temperature as shown in Figure 6 because heat loss to ambient is small, Because of the high temperature of the fluid and pipe a spray type cooler appears most desirable. The cooling capacity obtainable in spray coolers 28 and 18 inches long is plotted in Figure 6 (calculations are in the Appendix). As presently designed, a maximum of 28 inches is available. Considering the maximum requirements of about 33,000 Btu/hr, it is apparent that 18" of spray cooler is probably sufficient for the job and that a 28" cooler would allow ample reserve cooling area, It appears that full power operation down to about 3000F should be possible. At a vaporization rate of 1000 Btu/lb of water, 30 lbs. of water per hour or 4 gal/hr will be needed. 5.4 NaK and Water From the standpoint of heat input and cooling requirements, NaK and water fall well within the limits defined by Pb-Bi and Hg. Preheating is not requiredo For NaK, about 7000 Btu are required to attain 1000~F, and at 80 gpm the pump work input is about 14,000 Btu/hro Thus, both the heater and spray cooler designed for the Pb-Bi case will be more than sufficient for NaKo The water-cooled cooler will be necessary for water tests. 5.5 Bismuth and Sodiwn Bismuth and sodium isnvolve no additional problems or considerations except that a larger amount of preheating will be needed for the bismuth0 This can easily be provided by an additional wrapping of 2 resistance wire circuits on the dump tank.

Page 8 6(0 Pressure Loss The head loss in various sections of the loop and the operating characteristics of the complete system for mercury and NaK are shown in Figures 7 and 8 respectively. The head-flow characteristics for the various fluids considered are virtually identical in many respects because the Reynold's Number is sufficiently high so that the friction factor is not particularly sensitive to Reynoldgs Number. Hence the curves are generally applicable also to water and mercury. The exception to this general applicability lies in the following two factors: 1 o) The test section throat pressure for all fluids must be approximately 0 psia and the pump suction pressure about 14 psia. Therefore, the head rise required from test section throat to sump is inversely proportional to fluid density. This limits the minimum usable throat velocity, (about 5 ft/sec for Hg and 60 ft/sec for NaK). 2.) The pump horsepowers thrust loads, pressure stresses, etc, depend directly on fluid density for a given head rise. Hence a maximum head of about 45 feet obtainable at 1800 rpm seems limiting with mercury (about 20 hp and 260 psia) o However, it is expected that 3600 rpm and 180 feet head should be feasible with NaK or water (only about 1l5 hp and 20 psia) o It is expected that water tests with minimum velocity similar to that obtainable with mercury can be made by applying a suitable vacuum to the sump to obtain the suction head available with mercury under atmospheric sump pressure0 This does not appear feasible with NaK because the in-leakage of air could not be avoided. The pipe friction loss was based on the layout as shown in Figure 1. The various components have a pressure drop equivalent to the following length of l1" pipe0 45~ elbow 2.0 ft. 900 elbow 2.7 ft. Straight-run Tee 2 ft. Valve max, 40 ft, min. 10 ft. depending upon type of valve finally selected. Since a variety of conf igurations may be used for the testsection venturi and no precise data is available in any case, a maximum and minimum head loss were considered consistant with current practice. The maximum loss is 20% P between inlet and throat and the minimum is 10%o These were used as the criteria for both the flow meter venturi and the test section venturi. The flow meter venturi has been sized to provide a minimum of 2 inches hH under minimum flow conditionso This was deemed satisfactory to provide acceptable precision. The maximum.H is then about 30 inches0 ZkP across the test section venturi varies according to the pressure at the venturi inlet since, in order to obtain cavitation with the low vapor pressure, a pressure of approx= imately zero is required at the throat of the venturio The

Page 9 pressure reduction required of the downstream valve (sump tank must be maintained at about atmospheric pressure) can then be determined from the pressure at the test section exit and the friction losses in the remainder of the loop Tables III and IV show the detailed data upon which Figures 7, 8 and 9 are based. These results indicate that flows as low as 4 gpm, Vthroat 5 fps, can be obtained with mercury considering an equivalent 10' or 1L" pipe head loss thru the upstream valve. With NaK the minimum possible flow rate is 47 gpm (Vthroat 61 fps) under the same conditions9 if atmospheric pressure is to be maintained in the sumpo REFERENCEo l 1. Hammitt, Fo G. and Desai, Bo Co, Continuous Flow Fluid Tunnel Cavitation - Erosion Facility, Engineering Research Institute9 University of Michigan 461:1117-3?P, May 19570 2. Hammitt, F. G,'"Considerations for Selection of Liquid Metal Pumps', Chemical En ineerin Progress, May, 1957 3. Liquid Metals Handbook, Atomic Energy Commission and Department of the Navy, NAVEXOS P 733 (Rev.), June, 1952 4. Liquid Metals Handbook Sodium T NaK Supplement, Atomic Energy Commission0 Departmenrt of the Navy, July, l955X

Page 10 HEAD LOSS FOR MERCURY FLOW THROUGH LOOP TABLE III Flow V H Hd Rate _P_ e s d psia ft gpm fps ft globe "tY"t ft 40 6 o32 1672 48s 24 45o46 43 72 3303 5o26 ~672 33o41 3150 30029 26o7 4.22 672 21o50 20o27 19.49 20 3l16 6ha72 1205 11036 10o92 Flow H A Head to be Dissipated V Rate o loss by Downstream Valve throat ft ft gpm ft globe I'Y'l globe?lytt fps 4~L9o.3 6.62 30814 L6. 52o08 33 3 27236 475 283 2902i8 21.540. 3 43_ 36 26.7 3.26 2O02 140 8 15. 2 34176 losso a straight run tee,, static head, and minimum possible valve loss to return fluid to pump suction heado

Page 11 HEAD LOSS FOR NaK FLOW THROUGH LOOP TABLE IV F1 ow H Rate pipe Hd Vi psia ft gpm fps ft globe tY"t f t 80 12.7.2 194.48 183.61 176.56 66.7 10.5.2 133.17 125.52 120.69 53.4 8.4 85.22 80.32 77.24 40 6.32.2 49.32 46-54 44.80 Flow Hv A H Head to be Dissipated V Rate o loss by Downstream Valve throat ft ft gpm ft globe tyll" globe ttyt" fps 8o 1 8.90 68X44 57.25 90 46 83101.6275 104.16 66, l1.752 728' 80.2 66.7 1. 60.72 53.07 5 35 86.840 569. 54.71 49.81 69.53 40o 54- 50o.8 47.30 z:iHloss = friction loss of 15 ft. of pipe, 3 long radius els, a straight run tee, static head, and minimum possible valve loss to return fluid to pump suction head.

THROTTLING VALVE METERING TEST VENTURY PVi NTURY P_ -vo M T OR SPRAY 2.2' COOLER 2.5' PUMP LONG Pb-Bi ||_ I IMPELLER L a NaK THROTTLING VALVE PS COUNTER-FLOW WATER COOLER FOR TO STORAGE | MERCURY - 7'LONG TANK V 9. 9.7' 1 FLOOR Figure 1. Sketch of Cavitation Loop Layout.

16000 14000 12000 10000 8000 0 6000 I-.I 4000 t' 2000 a HEAT ADDED IN (3 XQ/ I~J/ PUMP TANK 0 200 400 600 800 1000 1200 FLUID' TEMPERATURE F Figure 2. Heat Requirements of Various Liquid Metals.

PUMP WORK BTU/HR X 10 20 5 10 15 20 25 30 55 40 5 18 L / "eHg Bi, Pb-Bi 12 10 PUMP HEAT INPUT 8 /n- HPvs BTU / HR 4 0 10 20 30 40 50 60 70 80 90 100 CAPACITY, GRM. Figure 3. Pump Requirements for Various Liquid Metals as a Function of Capacity.

60 50 / 7'Hg COOLER / 40 x 30 I-, I HEAT LOSS TO AIR z | I TOTAL LOSS OF PIPE 10o L \ AND PUMP. I \R-15' UNINSULATED PIPE UNINSULATED PUMP 0 50 100 150 200 FLUID TEMPERATURE, OF Figure 4. Heat Losses in Mercury Loop.

5000 2"INSULATKIN, 20' OF PIPE I" SUPEREX -M 4000 If THERWOBESTOS. I-.-oo (, CD g 2000 / 3INSULATION o0 PUMP (16"dia I4uL) Ij SUPEREX- M 2' THERMOBESTOS. 0,_...,..t,,__,,,1.......,._,_ _,.....,____:__.___,1_ 0 200 400 600 800 1000 1200 FUID TEMPERATURE, OF figure 5. Heat Loss of Insulated Pipe and Pump.

350 MEAN H20 TEMP: 2000F L=28" 250 200. x MEAN H.O TEMP o15 200OF LOS8" 100 50 HEAT TO BE REMOVED AT MAX, PUMP OUTPUT WITH LEADBISMUTH = 33,00 BTU /HR 0 0 200 400 600 800 1000 12 FLUID TEMPERATURE,OF Figure 6. Heat Loss in Spray Cooler.

50 1800 RPM\ PUMP DISCHARGE HEAD REQUIRED TO GIVE ZERO THROAT HEAD GLOBE VALVE (FULL OPEN) 45 Y"Y VALVE (FULL OPEN) / / - I >VENTURI INLET HEAD REQUIRED \ O GIVE ZERO THROAT HEAD. 40 PUMP CHARACTERISTICS //VENTURII OUTLET HEAD L / %/ / MIN. a MAX, II / / 25 / / // 1200RPM / / / PUMP DESIGN POINT, 0<~~;I }/I // 20 / 15 900 RPM / 9O/// -HEAD TO BE DISSIPATED BY DOWNSTREAM VALVE. 10 / S 1// o0 L& // HEAD LOSS BETWEEN VENTURI "E / / PDISCHARGE AND SUMP 5 aP' XB it / o GLOBE VALVE (FULL, OPEN).,,. tJ Y" VALVE (FULL OPEN) Io, FLOW RATES GPM. Figure 7. Loop and Pump Characteristics f'or Mercury.

250 3600 RPM 225 PUMP DISCHARGE HEAD 200 \ REQUIRED TO GIVE ZERO THROAT HEAD GLOBE VALVE (FULL OPEN) \'0Y" VALVE (FULL OPEN) 3000RPM.\/ 175_ PUMP CHARACTERISTICS. 1/i- VENTURI INLET HEAD REQUIRED TO GIVE ZERO THROAT HEAD. ISO VENTURI OUTLET HEAD 125 24b00 RPM / 11/, MIN. A MAX. 125 / 1/ II/ / 100 / -/ HEAD TO BE DISSIPATED BY I \// DOWNSTREAM VALVE. 1800 RPM. / /I HEAD LOSS BETWEEN VENTURI 75 - / DISCHARGE AND SUMRP,/,Y, / "<GLOBE VALVE (FULL OPEN)'/// 1/'"C.a~JY" VALVE (FULL OPEN) / PUMP DESIGN POINT. 25 O 2Q0 40 88 bK: 3 I 0 20 40 60 80 100 120 FLOW RATE a GPM. Figure 8. Loop and Pump Characteristics for NAK.

14 PIPE 12 120 10 _00 V THROAT > 4 40. 2 20 0 20 40 60 80 100 FLOW RATE GPM. Figure 9. Pipe and Test Section Velocity. (Based on: 1-1/2 sch 40 pipe and test section venturi diameter 3 0.56 inch)

Page 21 7.0 Appendix 7.1 Calculations of Cooler for Mercury Loop erc Side: Nu 7 + 0.025 Pe0.8 hD (Ref. 3) Pe = Pr x Re Pr 1 o_ = 1.37 x 2.42 x 0.033 0.0227 4.83 Dv l85 x h6.3 x 1.61 x 3600 8l 5 Re =. = 5.8 x 105.925 x 12 Pe0~8 (.0227 x 5.8 x 105) 0.8 2050 Nu 7 + 0.025 x 2050 = 58.3 h= 4.83 x 12 x 58.3 = 2100 1.61 On the water side of the cooler: q 50,000 Btu/hr Q 20 gpm V 3.2 fps k 0.363 R — 1 e5 x 104 (turbulent) PrJ 5.0 hD 0 023 Pr0O4 RO 8 h _ 0.023 x 5' 4 x (1.5 x 104) 8 x 0.363 x 12 705 0.6 Hence 1, = )1 +x + 1 U Ehi diTo k d ho() 1 +.030/12 + 1 U 2100 9.4(l ) 705(.90) 1000( ) 1.T T 1.61i..' 340 A x= 1.9 x 7 = 3.48 ft2 12 Hg Temp Tlog mean qBtu/hr 100~F 20 23,700 120 30 35,500 15o 40 [47,400 7.2 Heating Circuits for Pb - Bi Eutetic q KA(tmm ax tsVaXns).06 x.0208(2100-1200) Lq~ - ~~.00533 328 Btu/hr/ft or 328/3.415 96 watts/ft

Page 22 K = thermal conductivity of insulating material Btu/hr -ft -OFo A = mean surface area to be transversed per foot of length. tmax 2100OF for wire tmaxins 1200F if fluid temp is 1000F. I = 96 11.8 amps (resistance of wire = 0.685Qr/ft) On a 220 volt line: L = 220 = 27.2 ft/circuit where resistance per ft in ohms. Above calculations are based on #20 AWG Nichrom -v from Lewis Engr. Co. Power - 220 x 11.8 = 2.6 kw/circuit On dump tank Heat req'd to melt total vol. of Pb-Bi 3200 Btu Heat req'd to heat tank to 3000F 2400 total heat input reqtd 5600 Btu 5600/3413 = 1.64 kw hr. 3 circuits of resistace were'3 x 2,6 = 7.8 kw therefore, time _ = 0.21 hr or 12.6 min. is required to heat the tank and total volume of Pb-Bi to 3000PF To preheat loop to 300~F. q = 2100 Btu 2100/3413 =0615 kw hr. 2 circuits of resistance wire 2 x 2.6 = 5.2 kw 0,615 0.118 hr = 7,1 min, To preheat sump tank to 3000F. q j 3000 Btu 3.000/314.13 - 0.88 kw hr 4 circuits of resistance wire 4 x 2.6 10.4 kw o.88/o10,4 0.0845 hr = 5.06 min To heat sump tank and Pb-Bi from 300~F to 10000F input to tank 7700 Btu input to Pb- Bi= 9700 17400 Btu

Page 23 17400/3413 = 5o1 kw hr 510 — -= 0 49 hr or 29 4 mrain Total electrical power required Dump tank 3 circuits Sump tank 4 Loop 2 9 circuits @ 206 kw each. Required power approximately 24 kw 703 Heat Loss in Spray Cooler Nu = hD = 7 + 0.025 PeO~8 Pr Pb-Bi = 0.0282 Reference 3 Pr NaK = 0.012(at 500F) Reference 4 R Pb-Bi 7 x 10 R NaK = 4 x 105 Nu PbBi 7 +.025 (.0282 x 7 x 105) 0.8 75 5 Nu NaK =7 + o025 (o012 x 4 x 105 ) 0.8 29.0 h P - -B4 x 12 x 755 =3060 h NaK l.3 x 12 x 29.0 = 3300 h wNaK....1.61 h water, 2000 for boiling water, Reference 3 1- 1 r6/+ 1 + _+ _oo__ 90) U-PbBi - 3060 2000(1.90) + ) o Io1() 1611. UPb=Bi = 345 UNaK = 350 A X x 1.9 x 28 121 ft2 (28" length) 0.746 ft2 (18" length) q uA IAAT where Ti T = Teuio -Tboil.ing water Tfluid -200 except for cases where Tfluid C2120F. Then simple sensible heat cooling is assumed

Page 24. Fluid Temp - T q (28" Length) 2000F 0~OF 20,800 Btu/hr 400 200 83,50oo 600 400 167,000 800 600 250,000 1ooo 800 334, 000