T The System Hydrogen
eroxide-Permanganate pel the bomb to the target. As soon as the pressure within the motor fell below the effective pressure of the air ram, the vanes again were forced open. This cycle was repeated many times a second and developed the loud intermittent roar from which the term “buzz bomb” was obtained. Since the motor depericied upon ram effect of t’he air, the bomb had a stalling speed of approximately 200 miles per hour. It was therefore necessary to provide a method of launching the bomb by a separate system which would impart an initial velocity greater than the stalling speed in order that the motor should function properly and accelerate the bomb t o flying speed. The responsibility of developing an ,Imcrican counterpart of the J‘-1 and a method of launching iyas assigned to the Army l i r Forces. Research and development were expedited along several varied lines. Kith the invasion of the Sormandy Coast, a complete German launching system ryas captured, dismantled,
HE German “buzz bomb”, so effectively used by the Germans as a vieapon of destruction for a n area target and as a nerve-shattering missile, has been adequately described in the press. The bomb’s propelling mechanism was a 600-horsepower motor; into its hot combustion chamber, gasoline was injected continuously. The front of the motor contained a series of steel vanes, like Venetian blinds but V-shaped, which opened and closed Kith high frequency. In flight, the ram-jt,t Pffect of air opened the vanes and thus permitted air to enter the combustion chamber until an explosive mixture v a s obtained. The resulting spontaneous ignition developed pressure xhich closed the I’anes and forced the hot combustion gases out of the iear of the motor. The reaction against the closed vanes furnished the force to pro-
T
1 2
a
Present address, Georgia School of Technology, 4tlanta, Ga. Present address, Rennselaer Polstechnic Institute, Troy, T.Y . Present address, C ~ CChemical O Company, Bound Biook, S. I*.
160
February, 1946
INDUSTRIAL AND ENGINEERING CHEMISTRY
T h e Chemical Warfare Service was requested t o investigate and develop liquid chemical propellants for use I n launching the JB-2 flying (buzz) bomb. Three systems were investigated : concentrated hydrogen peroxidepermanganate, red fuming nitric acid-aniline, and mononitromethane-catalyst. Of these, only the peroxide system was found suitable for immediate field use. This paper discusses t h e general nature of t h e problem and the methods developed to study these rapid chemical reactions. A General Motors capacitance gage-cathode ray oscillograph-35 mm. camera oscillograph recorder was used t o
shipped, and re-erected a t Eglin Field, Fla. The Germans used the liquid chemical propellants 80-90% hydrogen peroxide and calcium permanganate or sodium Permanganate solutions. Little was known of the characteristics of hydrogen peroxide above 50% concentration or of satisfactory methods of manufacture, handling, and storage. Chemical Warfare Service was requested to undertake this development and initiated the Fred Project with the specific problem limited to the launching of the Air Forces JB-2 flying bomb. A preliminary investigation led to the conclusion that three liquid chemical propellant systems should be investigated simultaneously-namely, hydrogen peroxide-permanganate, mononitromethane, and fuming nitric acid-aniline. This conclusion was based upon the following results of the initial investigation: The Germans used peroxide-permanganate and it was known
t o work. The German reaction unit was constructed of an un-
familiar aluminum alloy, whose inside surfaces were coated with a wax. Intelligence reports contained many rumors of “explosions” a t the launching sites due t o the peroxide. Plants in the United States normally produced 30% peroxide, and satisfactory production of 90% material was questionable. Practically our entire capacity for 30 and 50% material was being used for other military needs. Hence a new plant would be required for the bomb program. Considerable research work had been carried out on mononitromethane a t the Guggenheim Aeronautics Laboratory, at California Institute of Technology, under joint Air Forces and Ordnance contracts. The possible use of a monopropellant which could be handled like gasoline required investigation. Available production capacities were small, and a new plant to meet the demand would be required. Exhaustive data on red fuming nitric acid-aniline were available, and this system or its counterpart, mixed acid-monoethylaniline was being used in thrust motors. Production capacity was avkilable for a large program. As developed later, only the first system was found t o be satisfactory for immediate use. The object of this series of papers is to present the methods of investigation that were developed to study these extremely rapid chemical reactions. The same methods can be used to study other chemical systems. It is hoped that generation of power by chemical propellants in the future will be applied to more constructive uses than launching a flying bomb, propelling of torpedoes and submarines, or driving gas turbines in a V-2 rocket. NATURE OF THE PROBLEM
Military considerations of mobility and camouflage decreed that a launching ramp be as short and light in weight as practicable. Structural strength of the flying bombs was the factor limiting the degree of acceleration to which the bomb could be subjected during launching. Army Air Forces tentatively specified an average acceleration of fifteen times gravity, 483 feet per (sec.)2, and a maximum of 188. To launch the bomb a t 250 miles per hour, a 150-foot ramp was required, similar to the German unit. The magnitude of the problem is then indicated by the following figures:
161
record the pressure obtained i n t h e chamber of a thrust motor as t h e chemical propellants were injected. Reaction data are presented for t h e hydrogen peroxide-permanganate system over a range of concentrations of hydrogen peroxide from 50 t o 90% and permanganate (MnO,-) from 5 t o 52%. The effect of decreasing the temperature of the reactants t o -23” C. was inappreciable. The decomposition reaction was found t o be “instantaneous”, depending only on the rate of mixing the reactants; therefore smooth pressure development was possible by controlling t h e rate of injection of peroxide.
Length of launching travel, ft. Launching speed, m.p.h. Launching period, aeoond Inatantaneous work being done at end of period, hp. Required gaa generation a t end of period, cu. ft./min. (at 850 Ib./sq. in.)
150 250 0 75 55,000
15,000
Figure 1 is a photograph of the German reaction unit in which the peroxide and permanganate solutions were blown from separate blow cases by high pressure (2200 pounds per square inch) air into a reaction chamber. The gaseous products d e veloped pressures of 800 to 100 pounds behind a piston in a “cannon”, 11.5 inches i.d. and 160 feet long. A steel fin on the top of the piston protruded through a narrow (0.5-inch) slot along the top of the tube and fitted into a 12’ angled keyway in the belly of the bomb. A small iron sled with wooden runners s u p ported the rear of the bomb and was confined in the channel track provided on top of the cannon. The end of the keyway and the front edge of the fin were angled 12” to hold down the front of the bomb during launching. Throughout this operation the acceleration created a moment of force around the center of gravity of the bomb. Kear the end of the launching, the bomb wings created an additional upward lift. To minimize the escapc of gases through the slot, a one-inchdiameter rod was suspended by small wires beneath the slot throughout its length. The piston was grooved along the top to accommodate this rod. As the piston shot forward, the rod was pushed up by the piston against the slot and the internal pressure kept the rod in place until the piston left the barrel. The design of the reaction unit was obviously complicated and empirical. While only one solenoid valve and two air-operated valves were used, it was not believed that the unit regulated the rate of injection to produce a uniform acceleration. However, before a design of a full scale unit could be attacked with confidence that the resulting unit would be satisfactory for field use, it was necessary to obtain the fundamental characteristics of the propellant system. The discission is limited t o the system hydrogen peroxide-permanganate. An adequate solution to the problem had to include answers to the following questions: Could the system develop sufficient gaseous pressure rapidly and smoothly a t high rates of injection? Could operating conditions be determined under which the system could be used? Would the system have acceptable latitude and sufficient safety factors? Were the various materials satisfactorily stable even under unfavorable field storage conditions? Would they be hazardous when handled by personnel? Could materials of construction be found for the use of the system and for storing and transporting the propellants? At the time this project was initiated, commercial production of hydrogen peroxide was standardized a t 30%, with 50% product made under special orders. The Buffalo Electrochemical Company developed a concentration process yielding a product which contained impurities of the same order as those in conductivity water and was, therefore, exceptionally stable. Most of the tests were made with this high purity product. Similar
INDUSTRIAL A N D ENGINEERING CHEMISTRY
162
,-
INLET NOZZLE
Vol. 38, No. 2
made fire resistant by covering all exposed wood with transitc. rSHEAR Safety showers of the t'readle type were located directly outside of the barricade openings. The roof of the pits was sandbagged to prevent flying missiles from endangering personnel. The safety glass wiiidoivs ordinarily were not used. Instead, mirrors were placed in the barricade opening to allow indirect observation, No windows were located between t,he barricade and thc instrument room. CLOSED BOMB STUDIES
t-
LREACTION CHAMBER 1
7 h"
Figure 2.
I
.+
Thrust Motor Assembly
A . Exit diameter (of exit nozzle) B . T h r o a t diameter (of exit nozzle) C. Over-all length (of exit nozzle)
D . Orifice diameter a t inlet nozzle
reaction tests were made on captured German peroxide containing about 900 p.p.m. of impurities, mostly as added stabilizing agents. Calcium and sodium permanganate solutions were obtained from the Carus Chemical Company. The calcium permanganate solution received was about 77%, based on Ca(Mn04)2*4H20. For the present purpose permanganate was determined and expressed as per cent Mn04-, since that is the active constituent and since the solution also contained approximately 1% NaMnOa. The dangerous nature of the work made it unfeasible to start the work with full scale equipment. To study the fundamental reaction characteristics of the system hydrogen pcroxide-permanganate, two types of small scale experimental equipment were used. The first was a closed, high pressure bomb in which the reactants could be rapidly mixed and the resultant prcssures and temperatures observed. I n contrast to this static method was a reaction chamber, commonly referred to as a thrust motor; this equipment provided for the continuous injection of reactant,s through inlet nozzles and the removal of products through an exhaust nozzle. Pressures developed in the thrust motor were recordcd by a continuous recording arrangement. TEST PITS
Reinforced concrete test pits were used for all runs with the thrust motors and the closed bomb. The pits consisted of two test barricades utilizing a common separating will; both were U-shaped.. They were adjoined by an instrument room. The larger barricade used for thrust motor runs %-as18 feet r i d e and 25 feet long, with two concrete biocks to accommodate the two thrust motors and accessory equipment. The smallcr barricade, approximately 10 feet square, lvas used for the closed bomb runs and gas impact work. The barricade walls were 18-inch concrete heavily reinforced with steel. Safety glass vr-indows protected by steel grillwork were located in the outside walls to permit observation of the experiments. The instrument room was direct,ly bchind the barricades and had no wall in common with them. The concrete flooring of the instrument room was separated from the barricade foundation by 2 feet of earth. All connections bctwecn the instrument room and the barricades were made b y 6-inch pipes overlapping 4-inch pipes. The space between t,he pipes was loosely paekcd m-ith oakum to prevent rain from washing back int,o the instrument room and to maintain a vi bra t,ion-frec connection, Safcty .features of the barricades, in addition t,o meehmical strength, included a fire spray system, to flood t,he barricade, which could be quickly operated by a valve from either inside or outside of the instrunlent room. The iiit,erior of the test pit was
REACTION R.~TE. The early tests on this system were carried out in an Aminco superpressure bomb of 1000-ml. capacity, held in an Aminco bomb shaker and heating jacket. The shaking mechanism was removed, and a releasable stop was made to pcrmit holding the bomb in a horizontal position. The stop had a pull wire to permit releasing the bomb from the horizontal position. This allowed a rapid rotation to the vertical position where a spring clip held it. A glass tube, approximately 1 inch in diameter and 10 inches long, having a thin bottom, was placed horizontally in the bomb. I n this position the glass tube held as much as 30 ml. of 90% peroxide. When the bomb was rotated to the .i.ertical position, the glass tube fell to t'he bottom of the bomb, where the appropriate amount of Ca(MnO& had been placed. This resulted in a measurable pressure rise in the bomb, which was followed by the General Motors capacitor gage to be described in the section on thrust motors. An 18-8 stainless steel liner was used to protect the carbon steel bomb proper. Early experiments showed that the rate of pressure developmeiit had little correlation with the results of t,he thrust motor work. I n the bomb the rate of mixing was so much slower than the rate of reaction that the mixing rate entirely govcrncd the rate of pressure build-up. Therefore, the results are not comparable and hence of little significance. The use of air or other DEVELOPMENT OF O x ~ c e PRESSURE. s gas under high pressure was required to accomplish the injection of peroxide and permanganate in the launching of the JB-2 bombs. To have adequate amounts of the high pressure gas in the field would require considerable heavy equipment in the form of compressors aiid storage cylinders. A means of eliminating this amount of heavy equipment would be advantageous. One suggest,ion was to produce the necessary gas pressure by the controlled decomposition of concentrated peroxide. This suggestion envisaged the slow decomposition of peroxide in a pressure reservoir, to produce oxygen under pressure and temperahre conditions at, which the water would be liquid. The oxygen pressure reservoir could then be used for the injection of peroxide and permanganate. The first attempts t o dccornpose concentrated peroxide were carried out in an open 250-ml. beaker using 100 ml. of 90% peroxide and adding to it a few drops of 0.1 hr KMn04; if this small amount was added without stirring, rather vigorous decomposition occurred but only in the surface layer. If the KMnO, was stirred into the peroxide, about 30 p.p.m. would cause uniform and total decomposition in about an hour. This amount of permanganate was used in att,empts to decompose peroxide in the Aminco bomb. The peroxide was placed in the bottom of a stainless steel liner in the bomb, and the I'3lnO1 solution added to it by tilting the bomb from a near horizontal position to the vertical position; the glass bulb containing Ki\ln04 then fell into the peroxide aiid broke against a steel rod. This method gave erratic results which were attributed to lack of uniform mixing. h special head for the Aminco bomb vias then made for adding peroxide to the bomb a t a controlled rate. The head contained a l1I4-inchstainless steel reservoir 2 ieet long, connected t o the inside of t,he bomb through the head and having a 1,/4-inch stainless st,eel needle valve a t the bottom and a l/2inch stainless steel tube a t the top. By this arrangement', peroxide was added to the catalyst-KbIn04, Ca(MnO&, Mn02,
February, 1946
INDUSTRIAL AND ENGINEERING CHEMISTRY
or Pb02-in the bomb a t a rate slow enough to allow the heat of reacti6n to dissipate so that the gage pressure recorded was due solely to oxygen formed by decomposition of peroxide and not a t all to steam pressure. The data from these experiments (Table 1) show that peroxide can be decomposed a t a controlled rate to give the calculated pressures. Discrepancies in observed and calculated pressures are due to the bomb being warm a t the time of final reading.
163
The flange holding the nozzle to the thrust motor chamber was grooved to fit the corresponding tongue of the chamber. The design proved satisfactory and afforded protection to the sealing surface, with the result that no nozzle was damaged in any chamber explosion, although some of them caused the nozzle to be thrown from 50 to 200 feet. IN~JECTION NOZZLES.Design of these solid stream nozzles (Figure 2) was based on velocities of approximately 100 feet per second a t the nozzle orifice. The orifice had a rounded inlet and a length of approximately its own diameter. Pressure drops TABLEI. CONTROLLED DECOMPOSITION OF 90% PEROXIDE through these nozzles were not measured, but were estimated to (400ML.) be in the neighborhood of 100 pounds per square inch at flow rates corresponding to velocities a t the orifice of 100 feet per secRun pressure, Lb./Sq. I n . Bomb NO. Catalyst Min. Final Calod. Temp. ond. I n comparing flow rates of two liquids entering the thrust 1 50ml.0.1 N K M n O l 45 1850 1850 ...,, . motor a t the same time, it was assumed that their volume rates 2 50ml.0.1 N K M n O d 55 1835 1850 Normal of flow were directly proportional to the nozzle orifice areas. 3 10ml. Ca(Mn0i)an 52 2200 1785 Very hot 4 5 g. MnOz 50 1950 1785 Warm No difficulties were experienced with regard to mechanical 5 5 g. PbO, 43 1950 1785 Warm strength of the nozzles, and no nozzle was damaged a t any time. a Solution was 41% MnOc-. The high liquid velocities of the solid stream jets afforded good mixing with the jets impinging on each other a t an angle of 135". This angle prevented the stream from entering the opposing If the peroxide reservoir became too hot, the peroxide decomnozzle. posed at a rapid, violent, and dangerous rate. This is in conBLOWCASES. The blow cases used to contain the liquids formity with the known fact that peroxide may "explode" a t or tested were constructed of 18-8 stainless steel. Two sizes were near its normal boiling point. constructed; the larger, used for the concentrated peroxide, had a total capacity of approximately 800 ml. It was conTHRUST MOTOR ASSEMBLY structed of 3-inch, schedule 80, 18-8 stainless steel pipe with A typical open reaction chamber or thrust motor assembly conwelding cap ends and was designed to have a bursting pressure sisted of a feed pressure storage tank, blow cases to hold the test main excess of 8000 pounds per square inch. Vertical baffles were terials, quick-opening liquid control valves, and the thrust motor. welded inside to prevent vortexing of the liquid during the rapid THRUST MOTORS. The design simulated in some respects the emptying of the blow case. The design was satisfactory, but large launcher breech used in assisted take-off (Figure 2). The small amounts of liquid were held up in the blow case and line motor was made of 3'/~-inch round bar 18-8 stainless steel, type which resulted in a mist or foglike flow a t the end of a run. The 304. The chamber proper was 2 3 / r inches i.d. and 61/2 inches small blow case, used for the permanganate, had a total capacity long, and was designed for a bursting strength of approximately of approximately 90 ml.; it was constructed of 1-inch, schedule 10,000 pounds per square inch. It utilized hemispherical design 80, 18-8 stainless steel pipe with welding cap ends No baffles a t the rear of the motor and a heavy flanged connection for the were used since the diameter was small enough so that vortexing exhaust nozzle. Three inlet nozzle entrances were provided in the would not be serious. The only change required was to enlarge side wvnll of the chamber, with two of them directly opposing the inlet fitting to 1/2-inch Army-Navy Standard Fitting as a reeach other and the third a t a 45" angle to one of them. This prosult of loading difficulties. vided flexibility in operation. Any entrances not in use were plugged. Side-entrance nozzles were FED LIGHT utilized since they more nearly approximated the injection to be used in the larger scale work. Two pressure tap locatiofis were placed in the side walls of the chamber between the nozzle entrance and the exhaust nozzle connection, and consisted of 1-inch diameter openings to take the General Motors capacitance gage. The nozzle entrances were 3 / p inch in diameter, which permitted any desired variation in nozzle size. The flange connection for the exit iiozzle was tongue-and-groove design to ensure adequate sealing with a soft copper gasket. Shear bolts held the exit nozzle to the thrust motor chamber proper and were designed to allow the exit nozzle to blow off between 2000 and 2500 pounds per square inch. This safety measure proved highly I /7 7 desirable in practice, since numerous explosions ocI1 SAFETY F G I N G MI U curred that blew off the exhaust nozzle without CIRCUIT any damage t o the thrust motor chamber itself. L The stainless steel construction of the motor had adequate corrosion resistance for all the work carried out, and showed little or no evidence of corrosion from any of the runs. I CAMERA 1 I E x a a u s ~NOZZLES.Venturi type nozzles were 115 V.,60 C.RS.REGULATE0 used (Figure 2). No effort was made to introduce any cooling to the exhaust nozzle, since the runs never exceeded 2 seconds and were usually less. The nozzles showed excellent life on these short runs. 'igure 3. Instrumentation Arrangement POWER SUPPLY
.
INDUSTRIAL AND ENGINEERING CHEMISTRY
164
T.4BLE
Run No. 3 5 6 7 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 27 28 29 30 31
33 34 37 38 39 40 41 42 43 44
45 46 47 45 49 50 51 53 54 55 56 57 58 59 60 61 62
63 64
Peroxide
n 200 250
250 500
500
750 750 750 750 750 750 750 750 750 750 760 750 750 750 750 750 750
750 750 750 750 750 750 750 750 750 750 750 750 750 750 750 750 750 750
750 750
500 500 500
500 500 500 800 800 800 800 500 500 800
90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
io io
70
io
90 90 90 70 71 90 90 89.5 89.5 59.5 59.5 59.5 89.5 59.5 89.3 89.3 89.3 89.3 89.3 59.3 89.0 89.3 89.3 89.3 89.3 89.3 59.3 59.3 52 72 62 51.3 89.3 59.3
Permanganate
111.
%
50 25 25 50
52 52
50 75 75 75
2 1 0
75 75 75 75 75
ZP IS
75 75 75 75 37.5 37.5 37.5 37.5 37.6 75 75 ,.1.3
75 75 75 75 75 75 75 75 75
75 75
I!
(0
50 50 :0 25 10 80 125 100 100 100 100 100 100
52
52 52 52 52 52 52 52 52 52 52 52 35 35 35 35 35 52 52 35 32 35 35 35 520 52b 41 41 41 41 41 41 41 42 42 42 42 42 42
42 42 42 42 42 42 42 42 42 42 42 42 32 42
Peroxide 0,080 0.180
0.180 0.254 0.254 0,254 0.254 0.254 0.254 0.254
0.254 0.254 0.254 0.254 0.254 0.254 0.254 0.264 0.254 0.254 0.254 0.254 0,264 0.284 0.254 0.254 0.254 0.254 0.254 0.254 0.254 0.254 0.254 0.254 0.254 0.254 0.254 0,254 0.254 0.254 0.254 0.254 0.225 0.228 0,228 0.225 0,225
0.228 0.228 0.228 0,225
0.225 0.228 0.295
0.228
11. EFFECTO F
Xozsles, Inches Permanganate 0.025 0.057 0,057 0.080
0.080 0.080
0.080 0.080 0.050 0,080 0.080 0.080 0.080 0.080 0.080
0,080 0.080 0.080 0.050 0,050
0.050
0.080
0.057 0.057 0,057
0,057 0.050
0,080 0.080 0.050 0.050 0,050 0.050 0.080 0.080
0.080
0.080
0.080 0.080 0.080 0.080 0.050 0,057 0.057
0,057 0.05; 0.05, 0,057 0.057 0.05; 0.057 0.057 0.057 0.057 0,057
hrARIIBLES OK
Exhaust 0.258 0 562 ~
0,562
0.795 0.795 0.795 0,795 0,795 0.795 0.795 0.795 0,795 0.795 0.795 0.795 0.795 0,795 0.795 0.795 0.795 0 795 0.795 0.795 0.795 0.795 0.795 0.795 0 795 0.795 0.795 0.795 0,795 0.795 0.795 0.795 0,795 0.795 0,795 0.795 0.562 0 . 795 0 , 795 0.795 0 562 0,662 0.562 0.562 0.562 0.562 0,562 0.562 0.562 0,562 0.562 0,562
Since relatively small amounts of FEEDPimssum SYSTC~IS. liquid were used over comparatively short periods, it was ncver necessary to use pressure regulating devices on the feed pressure system. A nitrogen cylinder reservoir with a capacity of approximately 1.5 cubic feet was pressurized Kith either nitrogen or compresscd air and afforded ample volume to maintain pressure for any one run. The difference in pressure between the start and finish of a run was never more than 2% at 1200 pounds per square inch. Xitrogen or compressed air was used for feed pressure to the blow cases, and the piping was arranged to permit pressurizing from the instrument room by means of a ~ d v exe t'ension. The valve and control were AuTo&fancCOXTROL I-ALVES. taken from a Kavy jet-assisted take-off, 38 ALDW-1500, thrust motor unit manufactured by the Aerojet Engineering Corporat,ion. This valve consisted of a main hydraulic cylinder activating two liquid valves t'hrough a yoke, so arranged that the liquid pressure tended to keep the valves closed. The necessary hydraulic pressure to actuate the hydraulic piston that opened the valves n-as derived from an electropneumatic-hydraulic system. TUBING ASD FITTINGS. A11 connections which were frequently used were constructed of flared tubing and .-\rmy-Savy aircrafttype flared tube fittings. These fittings were constructed of 18-8 stainless steel wherever contact with hydrogen peroxide Fas encountered, Standard commercial steel fittings were used
~
I
Vol. 38, No, 2
RESULTS
Pressures, On blowcase Cas 950 Nz K? 900 900 x2 900 N? s9 900 h-2 900 N? 900 900 N Z 900 NZ 900 N? 900 N2 900 Nz 900 h'2 1500 N9 900 N2 900 Xa N:, 900 900 NI 870 N 2 N2 900 900 N2 900 NZ 880 N1 900 N2 910 N, A-2 900 N? 900 N? 900 Air 1000 Ais 1000 Air xooo Air 1000 Air 800 Air i200 Air 1000 Air 1000 Air 1000 Air 1000 Air 975 Air 1200 Air 1200 Air 1200 Air 1200 Air 1200 Air 1200 4ir 1200 Air I150 Air i200 .4ir 1200 Air 1200 Air 1200 .4ir 1200 Air 1200 Air I200 Air 1200
Lb. per Sq. In. IASP
570
650 650 520 560 550 550 550 550 500
650 550 550 500 550 550 600
550 525 575 550 600 600 550 550 550 600 600 566 587 598 610 529 706 623 693 625 591 635 94 9 678 710 650 920 580 550 840 920
910 870 820 800 730 930 860
FASP 750 750 700 500 800 850 550 500 520 550
550 550 550 900 500 500 550 500 475 500 500 550 600 550
__ SSP 0.06 0.05
0.05 0.05 0.05 0.06 0.06 0.06 0.06 0.08 0.06 0.06 0.06 0.05 0.06
0.06 0.05 0.05 0.05
0.05 0.05 0.05 0.05 0.05
500
0.05
500 550 600 500 472 448 560 54 1 706 659 671 625 5-79 625 1000 744 750 650 930 920 930 580 990 940 940 560 820 810 960 930
0.05 0.04
0.04
0.06 0.04
0.07 0.07 0.07 0.07 0.08 0.10 0.08 0.03 0.03 0. 10 0.04 0.01 0.02 0.02 0.05
Time, Seconds ___ESP E1 1.25 1.40 0.25 0.59 0.29 0.57 0.38 0.69 0.42 0.72 0.63 0.79 0.68 0.52 0.63
0.65 0.67 0.64 0.64 0.63 0.23 0.66 0.66 0.65 0.46 0.43 0.37 0.33 0.57 0.55 0.67 0.32 0.31 0.55 0.59 0.18 0.50 0.47 0.69 0.67 0.17 0.19 0.36 0.34 0.44 0.43 0.69 0.26 0.24 0.27
0.02
0.68 0.59 0.71 0.71 0.68 0.72 0.67 0.61 0.52 0.46 0.77
0.02
0.79
0.05 0.05 0.05 0.04 0.05 0.05
0.05 0 05
0.80
0.81 0.87 0.78 0.75 0.74 0.39 0.75 0.73 0.68 0.67 0.73 0.71 0.68 0.65 0.65 0.77 0.55 0.55 0.79 0.75 0.26 0.66 0.88 0.53 0.86 0.58 0.63 0.79 0.53 0.76 0.53 I .OG 0.72 0.51
0.79 1.07 1.09 0.97 0.94 1.10 LO5 1.04 0.93 0.56 0.74 I .22 1.1,
-_ nh 1 I .I!) 0.23 0.24 0.33
0 37 0 , !57 0.6? 0,3T 0 St' 0 61 0 58 0 5s 0.57 0. IS 0.60
0.61) 0.68 0.41
0.35 0.32 0.28
0,5% 0.50 0.62
0.27
0,26 0.54
0.53 0.13 0.46 0,4!)
0.62
0.61~ 0.11 0.11
0.26 0.20 0.41 0.40 0.6!4
0.22 0,2:.: 0.25
0.M 0.5,; 0.66 0,61j
0.0:: 0.65 0.62 0.37 0.47 0.41 0.70
0 77
in all cases where corrosion resistance was nQt necessary. These fittings proved adequate a t pressures up to 2000 pounds per square inch and permitted quick assembly and disassembly after the original tubing had been flared and made up. For connection? in which there was danger of contact w-ith hydrogen peroxide, Silicone grease was used in place of standard pipe lubricnnth. Valves were of forged or stainless steel, and were globe, gate, o r needle design as required. Bar-stock needle valves were usrtl when no liquid flows were encountered, since t,hese valves pruvideti adequate mechanical strength. INSTRUMENT DESIGN AND OPERATION
PRESSURE RECORDIKG. Reaction pressures were measured with the indicator equipment4 made by Research Laboratories Division, General LIotors Corporation. It consisted of a pressuresensitive element (capacitor gage), a link-coupled oscillator detector (LCOD), and its link-coupled power supply (LCPS). The direct-current output from the LCOD is a direct linear function of the pressure applied to the gage. This output rvtt:~ fed into a cathode-ray oscilloscope, and the resulting trace was photographed on 35-mm. motion picture film. General Elec4 This equipment is described in detail in the G M C Instruction Slanuai and in S.A.E. Journal [52, 534-5G (1944)l. The pressure-sensitive element was built by General Motors according t o the design of B. H. Sage of the U. S. Bureau of Mines Explosives Laboratory.
'February, 1946
INDUSTRIAL AND ENGINEERING CHEMISTRY
165
TABLE I1 (Continued) p.un So. 65 66 67 68 69 70 71 72 73 74
Peroxide Mi. % 800 89.3 800 89.3 800 89.3 89.3 800 72 800 800 72 72 800 800 72 800 72 72 800 75 800 89.3 89.3 76 800 89.3 77 800 89.3 78 800 79 800 89.3 80 800 89.3 81 800 89.3 82 800 89.3 83 800 89.3 89.3 84 800 85 800 89.3 86 800 89.3 89.3 87 800 89.3 800 88 89.3 89 800 90 800 89.3 89.3 91 800 89.3 92 ,800 93 800 70 70 94 800 89.4 95 800 96 800 89.4 97 800 73 '38 800 73 73 99 680 75.1 100 800 101 800 75.1 75.1 102 520 89.7 103 800 104 800 89.7 48.4 I05 800 48.4 106 800 50.2 108 800 50.2 I09 800 110 800 89.7 111 800 89.7 112 800 89.7 89.7 113 800 50.4 114 800 50.4 115 800 50.2 116 660 pH = 0.7 b pH
Permanganate Nozzles, Inches Mi. % Peroxide Permanganate 100 35 0,228 0.087 0,228 100 0.087 25 0.228 100 15 0,057 100 5 0.057 0.228 100 0.057 0.228 52 100 41 0.228 0.057 0,228 0,057 100 35 0.228 0.057 25 100 0.228 0.057 100 15 0.228 100 5 0.057 100 41 0.228 0.057 41 0.228 0.057 100 41 0.228 0.057 100 41 0.228 0.057 100 100 50d 0.228 0.057 100 0.228 0.057 26d 0.228 50d 100 0.057 100 41d 0.228 0.057 100 41d 0.228 0.057 25d 0.228 100 0.057 100 41 0.228 0.057 41 0.228 0.057 100 41 0.228 0,057 100 41 0.228 0.057 100 42 0.228 100 0.057 100 42 0.228 0.057 41 0.228 0.057 100 41 0.057 0.228 100 41 100 0.228 0.057 41 0.228 0.057 100 41 0.228 0.057 100 41 0.228 100 0.057 41 0.228 100 0.057 41 0.228 100 0,067 41 0.228 0.057 100 41 0.228 0.057 100 41 100 0.228 0.057 41 0.228 100 0.057 41 0.228 400 0.080 41 0.228 400 0,080 41 0.228 400 0.080 400 41 0.228 0.080 400 52 0.228 0,080 0.228 400 52 0.080 52 0.228 400 0.080 0.228 360 52 0.080 41 800 0.228 0.161 41 0.228 0.161 800 41 0.228 0.161 800 41 0.228 0.161 800 0.228 0.057 41 82 = 9.55. Cold run. d Sodium permanganate,
Exhausi 0,562 0,562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562O 0.56ZC 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.56ZC 0.56ZC 0.56ZC 0.562c
tric type CRO-5-S and DuMont type 208 oscilloscopes were used. A special input terminal and switch were installed according to directions given in the GMC Instruction Manual. The best available continuous camera ww the General Radio type 651-AE oscillograph recorder, although several old-fashioned movie cameras were also used after modification t o eliminate the intermittent film motion and shutter action. The instrument arrangement is shown in Figure 3. A l/pa-watt neon lamp, operated a t 60 cycles per second put the time base on all films. SAFETYAND COORDINATION.After all personnel had cleared from the danger area of the test pit, the red light circuit in the test pit was turned on manually. This circuit posted red lights all around the test area to warn that firing was imminent and provided power for the coil circuit of the arming relay in the safety fjring circuit. The rapid sequence of operations during each test was coordinated by the safety firing circuit (Figure 4). This unit activated five load circuits in rapid succession, with an arbitrarily +djusted time interval between successive load circuits. At an adjustable time after activation of the fifth load, all load circuits were automatically deactivated and the entire unit was reset. The automatic deactivation and resetting could be prevented to allow any particular test to continue indefinitely if desired. The safety firing circuit was designed for general use, and in this system only the third and fourth load circuits were active. They operated the camera and fuel injection valve, respectively.
0.662 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0.562 0,562 0,562 0.862 0.562 0.562
Gas Air Air Air Air Air Bir 4ir Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air Air h-2 3 2
N1
N2
Air
Pressures, Lb. per Sq. In. O n blowIASP FASP 1200 870 920 1200 920 880 1200 860 910 1200 840 870 1200 800 820 1200 810 820 1200 810 820 1200 820 810 1200 810 820 1200 770 760 1200 840 930 1200 840 930 1200 780 830 1200 875 1040 1200 920 930 1200 920 965 1200 920 980 1200 860 980 920 1200 960 1200 890 980 1200 920 960 1400 980 960 1200 930 910 1000 820 790 620 800 700 600 490 510 1200 870 890 1200 810 780 1200 720 780 1200 820 760 1000 770 850 1200 880 910 1200 780 780 1200 760 710 1200 745 715 1200 815 755 1200 805 785 1200 795 825 1200 895 850 1200 860 935 1200 675 I 15 1200 615 ' 640 1200 675 645 1200 740 670 1200 905 830 1200 880 970 1200 890 960 1200 840 880 1200 750 860 1200 720 760 1000 ... ,..
SSP 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.03 0.02 0.02 0.02 0.02 0.03 0.01 0.01 0.01 0.01 0.02 0.01 0.03 0.03 0.04 0.07 0.01 0.03 0.03 0.03 0.02 0.02 0.03 0.03 0.01 0.03 0.06 0.01 0.08 0.05 0.04 0.04 0.01 0.02 0.02 0.03
...
Time, Seconds ESP EX 0.78 1.15 0.76 1.10 0.71 1.06 0.60 0.96 0.41 0.90 0.37 0.83 0.41 0.87 0.39 0.86 0.43 0.83 0.96 0.51 1.26 0.92 1.24 0.94 1.27 0.82 1.16 0.70 0.77 1.21 0.70 1.18 1.21 0.77 1.21 0.73 1.17 0.81 0.75 1.18 1.21 0.79 0.95 0.58 1.19 0.73 1.28 0.88 1.51 1.16 1.54 1.93 0.74 1.10 0.74 1.13 0.66 0.33 0.47 0.91 1.20 0.91 1.20 0.83 0.91 0.44 0.52 0.80 0.44 0.77 0.52 0.96 0.51 0.99 0.72 0.22 1.16 0.83 1.16 0.85 0.77 0.29 0.24 0.70 0.48 0.86 0.45 0.74 1.18 0.88 1.15 0.84 0.89 1.32 1.32 0.85 0.95 0.21 0.28 0.91
...
...
DSI 0.76 0.74 0.69 0.68
0.39 0.35 0.39 0.37 0.41 0.49 0.90 0.92 0.81 0.69 0.73 0.68 0.75 0.71 0.79 0.72 0.78 0.57 0.72 0.87 1,14 1.53 0.72 0.71 0.29 0.40 0.90 0.80 0.41 0.49 0.42 0.50 0.48 0.19 0.84 0.82 0.23 0.23 0.40 0.41 0.84 0.80 0.88 0.83 0.19 0.24
...
All loads except the fifth could be operated manually as well as automatically. The fifth load circuit could be activated only after a disconnecting switch was closed, the arming circuit had been on a t least 30 seconds, and the other four loads had been activated in their proper automatic sequence. FILMIDENTIFICATION. A titling board bearing identification numbers of a run was placed in front of the oscilloscope screen. The room lights were extinguished and the camera lens cap was removed. A flashlight spot was flashed briefly on the titling board, and the camera lens cap was replaced. A short strip of blank film was run off. GAGECALIBRATION.The instruments were allowed to warm up, and the capacitor gage was connected to an Ashcroft deadweight tester in the test pit. The oscilloscope and LCOD were balanced and adjusted to zero. The static oscilloscope spot was photographed with gage a t zero, then a t 1000 pounds per square inch, and again a t zero, using about a foot of film a t each pressure. Data, such as LCOD gain position, vernier, and film footage, were recorded. A short strip of blank film was run off. PREPARATIOP OF TESTPIT. The sequence of operations in the test pit follows: 1. Calibration was carried out as described in the preceding section, the pit operator pressurizing the dead weight tester when so directed by the instrument operator. The gage was removed from the dead weight tester and inserted in the thrust motor. 2. Any necessary changes in the setup of the thrust motor were then made. 3. The drive gas reservoir was brought up t o pressure.
166
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 38, No. 2
I 4. The blow cases were disconnected, filled, and reconnected. 5 . The vent valve between blow case and main gas drive valve was closed. 6. All personnel cleared the pit. The pit operator, upon leaving the pit, turned on the red light circuit and blew the warning whistle. 7. Firing was then carried out as described in the following section. Then the vent valve was opened when the pit was first entered. 8. The capacitor gage was removed from the motor, cooled, washed under a stream of water. dried. and placed in the dead weight tester. (Care was taken to see that thk electrical connection was not wet during cleaning.)
FIRING.The following as the firing sequence: 1. After the red lights came on and the warning whistle blew, the arming switch on the safety firing circuit was closed. 2. After a 30-second delay and after the officer in charge of the test pit opened the main drive gas valve and closed the necessary disconnecting switches in the instrument room, firing could proceed. 3. Room lights were extinguished, and the camera lens cap was removed. The starter switch on the safety firing circuit was pressed, and the run continued automatically. 4. When the run was completed, the camera cap was replaced, lights were turned on, and a short strip of blank film was run off. 5 . The fuel injection valve was reopened manually to blow air through the combustion chamber and thus flush out any residual gases in the motor. The disconnecting switches were opened, main drive gas valve was closed, red lights were turned off, and outside observers were notified that the pit could be reentered. 6. The film was again identified as described in the section on Film Identification.
RESULTS AND CONCLUSIONS. Under all conditions of injection the initiation of the reaction was spontaneous and rapid. The
power deyeloped was characterized by a smooth rise wit 0.01-0.02 second to operating pressures as high as 1000 poundr per square inch. This pressure was maintained during the i i n tire period of injection. Table I1 lists data of all runs. Various runs were s e l e c t d t,) illustrate t,he effect of altering certain variables. Figure 5 presents typical pressure-time curves. It show;, ttw normal types of curves expected-a short preliminary irregu!.) Y t,race, followed by a rapid rise to maximum height, a long f h r part corresponding to sustained injection, and a final tail-off region. This last region is, in general, sharply marked although i n n'i case is the fall to final chamber pressure as rapid as the initia; surge to full operating prcssure. This is doubtless due to tit;: injection of a migt or spray of peroxide from t h e residual liquid remaining in the blow case after the main bulk of the liquid ha8' been injected. Below each curve is a broken line which consti. tutes t'he time base. The dashes were caused by the alternaiv flashes of the two filaments of a neon lamp operating on 60-cyclo current; hence each flash corresponds to 1!12~ second. Figure ;. shows the relation bet,ween the heights and duratioiis of mAximum pressure using 90, 70, and 50W peroxide, respcctivcla The maximum pressure is higher and its duration longer, the higher the concentration of peroxide. To characterize the various runs and to analyze the data 0;)tained from them, it was necessary to dcfinc ccrtain values which have been measured on the film strips: The initial maximum pressure (IMP) was taken as the value of the pressurc \ v h e ~ it had reached a steady state. The initial average sustaineii. pressure (IASP)was taken as the average pressure during thv first part of the run, after full pressure had been reached. Th: finaI average sustained pressure (FASP) was the average prcssurci
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
February, 1946
167
RUN NO. 98-81-1 90% PEROXIDE
RUN NO. 60-81-1
k-
70%PEROXIOE
_ _ _ _ _ _ _ - _ _ _ _ .._-_---_-_____-_
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ i _ _ _ _ _ _ _ _ _ _ - - - - - -
RUN NO 62 -81-1
Figure 5.
50XPEROXlDE
Typical Operating Curves t o Show Effect of Different Concentrations of Hydrogen Peroxide
near the end of the run, before the pressure had begun to fall off markedly. I n many runs IASP and FASP were nearly identical. Yet it was necessary to define these terms to provide for certain runs which showed a distinctly lower or higher pressure during the second half of the run. The start of injection (SI) is defined as the time a t which the first rise in pressure was noted. The start of sustained pressure (SSP) was taken as the time a t which I M P was reached. The end of sustained pressure (ESP) is the time a t which the FASP had fallen to approximately 90% of its value near the end of a run, and after which the pressure falls off in a regular manner.
TABLE 111. PRESSURE DEVELOPMENT IN THRUST MOTORS AT VARIOUSINPUT AND EFFLUX RATES R~~ No.
NOnde Diameter, In.
H ~ Ohlnoa~ inlet
inlet
hauet
3 5 6 7 8 9 11
0.080 0.180 0.180 0.254 0.254 0.254 0.254
0.025 0.057 0.057 0.084 0.080 0.080 0.080
0.26 0.56 0.56 0.80 0.80 0.80 0.80
51 53 54
0.228 0.057 0.228 0.057 0.228 0.057
0.80 0.56 0.56
Volume, M1. HzOa MnOdSection A"
50 25 25 50 50 75 75
Pressure, Lb./Sq. In. IABP FASP
Time, Sec.
550
780 680 700 500 500 550 550
1.19 0.23 0.24 0.33 0.37 0.57 0.64
680 920 880
680 930 920
0.28 0.79 0.66 1.05 0.55 1.04
...
1.34 0.54 0.52 0.64 0.67 0.73
0.74
Section Bb
800 800 800
50 50 50,
Section CY,Blowcase Pressure 880 Lb. Nz per Sq. In.
9-17
0.254
0.080
0.80
750
75
540
540
0.59 0.68
(av.)
18
Section CC. Blowcase Pressure 1420 Lb. Na per Ss. I n . 0.080 0.80 750 75 850 900 0 23
0.254
0.34
Section Dd, Chamber Length 6.5 In.
64 85 87
0.228 0.057 0.228 0.057 0.228 0.057
0.56 0.56 0 56
800 800 800
100 100 100
860 920 910
930 960 970
In certain cases ESP is difficult to determine with accuracy, since it tapers off gradually; in those instances some arbitrary choice must be used. I n most cases, however, this quantity is easy t o fix since it is registered as a sharp break in the curve. The end of injection (EI) is the time a t which the pressure curve flattens out and becomes the trace of the gas pressure of the injection system. The duration of sustained injection (DSI) was calculated as the difference between ESP and SSP. These terms are illustrated in Figure 6. The films were read as follows: The film strip was placed on a sheet of millimeter graph paper on top of a pane of glass which was illuminated from below by an electric light. The vertical displacement between the calibration lines corresponding to zero and 1000 pounds per square inch given by the dead weight tester was read in millimeters. This value, multiplied by 100 and divided by the corresponding height for each item IMP, IMP, and FASP, gave the pressures. The number of dashes, l / ~ z ~second each, divided by 120, gave the time in seconds for SSP, ESP, DI, and DSI. Table 111 illustrates the effect of differences in chamber pressure, injection pressure, injection rate, and chamber length. The chamber length was increased by means of a 9-inch extension on the thrust motor. Table IV illustrates the operating conditions obtained when the hydrogen peroxide concentration was varied from 50 to 90%; variations do not affect the manner of power development but determine only its magnitude per unit mass of propellant injected. Figure 5 gives pressure curves illustrating these runs. Under similar conditions for a series of runs, the reaction proceeds with remarkable reproducibility. Section A , Table V, shows a series of runs made under identical conditions, along with the measured results and the normal reproducibility expected. Sections B and C show two pairs of duplicate runs; curves are rcproduced in Figure 7.
0.76 1.14 0 77 1.17 0 71 1 19
IMP
Section Dd,Chamber Length 15.5 In.
75 76
I
0.057 0.56 800 100 840 930 0.92 1.26 0.057 0.56 800 100 840 930 0.94 1.24 a Propellant 90% HzOz, catalyst 52% MnOd-; blowcase Pressure 880 Ib. Nz per sq. in.; chamber length 6.5 in. b Propellant 90% HsOz catal s t 41% MnOd-. vol. HzOz/vol. MnOa- = lG/l: blowcase pressure i140 lg. air per sq. in.: chamber length 6.5 in. C Propellant 90 HzOz, catalyst 52% MnOr-; chamber length 6.5 in. d Propellant 9 0 2 HzOt, catalyst 41% MnOd-; vol. HzOz/vol. = 16/1. blowcase pressure 1140 lb./sq. in. In section D the ratio of rates of injechon of peroxide t o permanganate was lG/l because all of t h e peroxide
.,PRESSURE TRACE
0.228 0.228
'
.-TIME BASE -i-------- _- -_-_- ------1 --- ---_ __ -1-_ _- -- _ x -
SSP
Y
+P
I
El
DSI
entered within t h e time t h e first half of t h e permanganate entered.
Figure 6.
Definition of Values Measured on FilmBtrips
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
168
1
Vol. 38, No. 2
RUY NO. 7 5
1
t
Figure 7.
Reproducibility of Duplicate Runs (Cornpaisa Run 95 with 76, 85 with 8 9 )
A n evtrenie range of permanganate concentrations and of ratios ot propellant to catalyst is permissible and provides adequate safety factors for field use (Table VI and Figure 8). Section C, Table VI, shom no noticeable difference in runs in which the pH of the calcium permanganate solution was varied over the wide range from 0.7 to 9.55. Interruption in the flow of either reactant is without dangerous effect, as section B shows. A constant ratio
TABLEIV. PRESSLRE DEVELOPMENT IN THRUST NOTOM
AT
V-ARIOUS PEROXIDE COSCENTRATIOKS
of plopellant to catalysc was maintained, while the duration of flow of each liquid was controlled by altering the quantity of liquids loaded in the blow cases. It is essential, however, that the permanganate solution precede, or a t least arrive simultaneously with, the peroxide to prevent explosions. Table VI1 shows the effect of cooling the reactants. There is a slight but scarcely noticeable decrease in pressure, and no shortening of the cold runs as compared to those a t ambient temperature. The important point is that the cold runs were not inhibited; this corresponds to successful launchings. Any minor differences could well be due to increased viscosities and densities of the liquids at the lowered temperatures. Thus. thc SVB-
(Propellant, 800 ml. of H202 solution, catalyst, 100 ml. of 41% hInO4-; propellant catalyst ratio = 16/1; hlow'case pressure 11401b./sq. in. Koznle diameters: HAOZinlet 0.228 inch; hInO4- inlet 0.057 inch; exhaust 0.562 inch)
Run No. 58 59 60
conon f i s s u r e ,
H2O2,Y0
on 80 70
BO
61 62
50
TABLE
v.
IASP 910 870 820 800 730
KO. 9 11 12 13 14
15 16 17 Av.
7 =i 76 8li 87
Time, Set.- ,qv. sustained DSI DI Pressure X DSI 0.68 1.05 63 0.62 1.04 56 0.57 0 . 9 3 48 0.47 0 . 6 8 38 0.41 0.74 31
TABLE VI. EFFECTOF CATALYST ~ O X C E N T R A T I O N AND VOLUME ON PRESSURE DEI'ELOPMEYT Ih' TURUST hf0TOR.i R~~ perman- Pressure, Lb./Sq. In. Time, Scc. XO. ganate I.4SP FASP DSI DI
REACTIOXCHARACTERISTICS THRUST XOTO~S
REPRODUCIBILITY O F IN
R~~
Lb./Sq. In. FSSP 940 940 860 820 810
Pressure, Lb./Sq. In. [ASP FASP SbP Section A5 550 0 . OB 0.06 550 550 ZOO 0.06 550 0.06 520 250 0.06 550 200 0.06 550 ,150 .550 0. 06 550 550 0 . 06 350 0.06 540 540
0.63 0.68 0.63 0 65 0.67 0 64 0.64 0.63 0 65
0.79 0.82 0.80 0.81 0.87 0.78 0.78 0.74 0.80
0.57 0.62 0.57
Section Bb 0.02 0.02
0.92 0.94
1.26 1.24
0.90 0.92
840 840
930 930
Y20 910
Section CE 960 0.01 930 0.01
Time, Seconds ESP E1
0.79 0.73
1.21 1.19
Dbl
0.59
0.61 0.58 0.58 0. 57 0.59
0.78 0.72 SInOa-g exhaust hInOa-. exhaust bfnO&-:
Section A a , H203 Concentration 90% 527,hIn04930 960 0.74 40.6 860 930 0.75 35 870 920 0.76 25 880 920 0.73 15 870 910 0.69 J 840 870 0.57
1.19 1.14 1.13 1.07 1.04 0.92
69 70 71 72 73 74
Section A a , Hz02 Concentration 70% 52%MnOa800 820 0.39 40 6 810 820 0 34 35 810 820 0 39 25 810 820 0 37 0 41 1; 810 820 0 870 i60 0 49
0 88 0 81 0 85 0 84 0 81 0 94
58 57 54 55 56 33 9-17 (av.) 34
126 ml 80 60
25 10 0 . 7 pH 5.0 9.56
Section Eb 9 10 920 880 850 840 Section 600 540 600
940 980 920 930 880e
0 68 0 63 0 55 0 66 0 66
1 05 1 10 0 94 0 97 0.94
560 560
0.54 0.59
0.79 0.80 0 78
Cd
600
0.54
800 ml of HzOr 100 ml. of SInO,-. Nozzle diameters: Hz02 inlet 0,328 jnch; AInOr- 0.057;nch; exhaust 0.56 inch; blow case pressure 1140 lb./sq. in.; chamber length 6.5 inches. b 800 ml. of 90% Hz02. ;\ZnO4- concentration, 41%; nozzle diameters, blow case pressure and c h k b e r length same as A . C Pressure oscill'ations, 350 lb./sq. in. amplitude after start. d 800 ml. of 90% H102, 100 nil. of 5 2 r 0 MnOl-. Nozzle diameters: HgOt inlet 0.254 inch: inlet MnOh- 0.080 inch: exhaust 0.80 inch; blow ease pressure 880 lb. N2 per sq. in. Q
5 Propellant 780 ml. of 90% HzOz catalyst 75 ml. of 52% Nozzle diameters: H202 inlet 0.254 inch; hIn04- inlet 0.080 inch; 0.795 inch. blow case pressure 880 lb./sq. in. b Propeliant 800 ml. of 89.3% HzOz, catalyst 100 inl. of 41% Nozsle diameters: HrOs inlet 0.228 inch: SfJI04- inlet 0.057 inch; 0.562 inch; blow case pressure 1200 lb./sq. in. Pronellant 800 mi. of 89.3% HzOr, catalyst 100 ml. of 41% n055le d-iameters and blowcase pressure same as in section E .
63 64 65 66 67 68
INDUSTRIAL A N D E N G I N E E R I N G C H E M I S T R Y
February, 1946
169
RUN N 0 6 4 . HYOROGEN PEROXIDE 90%. PERMANGANATE SOLVTION 41%
-_--______i____----________________c________---------------
RUN NO. 67. HYDROGEN PEROXIDE 90%. PERMANGANATE SOLUTION 15%
_-----__----------_---_---------------t RUN NO 69. HYDROGEN PEROXIDE
70%.
PERMANGANATE SOLUTION 5 2 %
_________--_-_-----------------------
- -_ -- ____________--_-_---------------
_ I _ _ -
RUN N 0 . 5 4 . HYOROGEN PEROXIDE 90%.
S O M L . OF PERMANGANATE SOLUTION
-
______ ---_____-- --- __ -- __ - - _-_--- - --- -- ----- -- -- -- -- -- -- ---- -- - - -- --- --- - -- ---I
__ __ __ __
Figure 8.
4l$
Effect of Catalyst Concentration and Volume on Pressure Development in Thrust Motors
A series of runs on 73% peroxide, made by concentrating 35% technical grade, showed no distinguishable differences. A series was run to determine the effect of a large excess of calcium permanganate solution. Eight hundred milliliters of peroxide were used, varying in concentration from 48.4to 89.701,. The permanganate was either 41 or 52%, and 400 to 800 ml. were used. The runs were directly comparable to the normal runs for the amounts and concentrations of peroxide used, except that a large quantity of unused THE REACTANTS TABLE VII. EFFECTOF COOLING permanganate, in the form of a purple cloud, issued ($11 runs used same injection and exhaust nozzles throughout, 1200 lb. air pressure on blow from the exhaust nozzle. caaes, 100 ml. of 41% h h o a - , 800 ml. of HnOz) Runs were carried out to determine whether nitroPressure, Lb./Sq. I n . R u n Concn. of Av. of IASP Time, Sec. Temp., C. gen could be used instead of air pressure on the No. HzOz, % IASP FASP and F.4SP -07 blow cases; no difference was found.
tem permits of operation a t low temperatures. In one run bits of luting compound from a threaded joint fell into the peroxide blow case, which caused the peroxide to boil. The run was carried out to note the effect of the elevated temperature. The run proceeded satisfactorily and was indistinguishable from other runs with like concentrations.
Section A
77 78 91 92
89 89 89 89
3 3 3 3
782 875 872 806
828 1038 892 782
805 957 880 782
0 02 0 82 0 02 0 70 0 03 0 74 0 03 0 74
1 1 1 1
27 0 80 16 0 68 10 0 71 13 0 71
12 9 1 1
12 9 -23 -IS
(Comparable Normal Temperature Runs)
85 96
89.3 89.3
920 879
960 912
940 895
93 94
70 70
723 762
782 822
753 792
70
72
810
820
0.01 0 . 7 9 1 . 2 1 0 . 7 8 0 . 0 3 0 . 8 3 1.20 0.80
Ambient Ambient
Section B
0 . 0 4 0 . 3 3 0.66 0 29 0 . 0 7 0 . 4 7 0 . 9 1 0 40
-28 -28
-28 -28
(Normal Temperature Run)
815
0.02 0.37 0.83 0.35
Ambient
CONCLUSIONS
The thrust motor experiments indicate a wide range of conditions under which safe and successful operation can be achieved. The permanganate must enter the motor before or at least a t the same time as the peroxide. Peroxide concentrations of 50 to 90% and permanganate concentrations from 5 to 52% MnOl- ion have been successfully used with wide variation in the ratio of peroxide to permanganate volume. The developed pressure is greater and its duration longer with the higher concentrations of peroxide. RBLEASEDb y authority of the Chief, Chemical Warfare Service.
