US3705495A

US3705495A - Fuel systems and oxidizers

Info

Publication number: US3705495A
Application number: US253523A
Authority: US
Inventors: Leonard Greiner; Welby G Courtney
Original assignee: Texaco Experiment Inc
Current assignee: Texaco Experiment Inc
Priority date: 1963-01-21
Filing date: 1963-01-21
Publication date: 1972-12-12
Anticipated expiration: 1989-12-12

Abstract

7. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising a liquid composition consisting essentially of from about 59 percent to about 77 percent by weight of perchloric acid, from 0 to about 15 percent by weight of HNO3 and the remainder water, the amount of water being sufficient to form dihydrated perchloric acid with at least about 95 percent of the perchloric acid and a fuel selected from the group consisting of light metals, metal hydrides, and mixtures thereof.

Description

United States Patent Greiner et a1.

[ 1 Dec. 12, 1972 [54] FUEL SYSTEMS AND OXIDIZERS [73] Assignee: Texaco Experiment Incorporated,

Richmond, Va.

[22] Filed: Jan. 21, 1963 [21] Appl. No.: 253,523

[52] US. Cl. ..60/2l4, /215, 60/216, 60/219, 149/74, 149/109 [51] Int. Cl. ..C06d 5/08, C06d 5/10 [58] Field of Search ..60/35.4, 214-216, 60/219; 149/74, 75, 109', 23/152 [56] References Cited UNITED STATES PATENTS 3,083,526 4/1963 Hudson ..60/35.4

2,504,119 4/1950 Frazer et al. 149/75 2,968,539 1/1961 Wharton 149/75 2,975,045 3/1961 Perry et a1 ..149/

Primary Examiner-Benjamin R. Padgett Attorney-Stowe" & Stowell EXEMPLARY CLAIM 7. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising a liquid composition consisting essentially of from about 59 percent to about 77 percent by weight of perchloric acid, from 0 to about 15 percent by weight of HNO, and the remainder water, the amount of water being sufficient to form dihydrated perchloric acid with at least about percent of the perchloric acid and a fuel selected from the group consisting of light metals, metal hydrides, and mixtures thereof.

13 Claims, No Drawings FUEL SYSTEMS AND OXIDIZERS This invention relates to improvements in fuel systems and fuel oxidizers for reaction motors.

It is an object of the present invention to provide fuel oxidizers and fuel systems which have good performance and are relatively safe to handle in that they do not product toxic fumes, are very stable, and are relatively non-injurious to skin.

A further object is to provide fuel systems and fuel oxidizers which have good specific impulse and good density impulse and wherein the liquid component of the fuel system has a relatively high boiling point and a relatively low freezing point.

A further object is to provide a liquid-solid hybrid propellant system having particular utility and performance on boost-type missions but which may also be used for second-stage and sustainer missions. The propellant systems of the invention are of special utility in volume-limited rockets where the fuel density-impulse relationship is important.

These and other objects and advantages are provided in a liquid-solid propellant system comprising as an oxidizer dihydrated perchloric acid, and a fuel consisting predominantly of a light metal or a metal hydride and by an improved oxidizer for a light metal or a metal hydride comprising at least about 80 percent by weight of dihydrated perchloric acid.

It has been found that hybrid rocket propellants consisting of at least about 80 percent by weight of dihydrated perchloric acid as oxidizer and a fuel consisting predominantly of a light metal or a metal hydride provide very high performance on an integrated specific impulse and density basis, high safety, long storability and the capability of operation with the thrust of the reaction motor controlled over a wide thrust range by controlling the flow of liquid oxidizer to the fuel component of the hybrid system.

The following selected hybrid systems have been found to provide very satisfactory results:

Table I shows calculated performance data including the specific impulse for two illustrative rations of reactants in the propellant system ZrH HClO 21-1 0.

Thermodynamic Characteristics: Chamber Exhaust Chamber Exhaust Temperature, K 4212.0 2961.1 3353.8 2425.8 Moles of Gas,

moles/g 1.683 1.5475 1.5366 1.5128 Combustion Products. moles/100g Gaseous Atoms 11 0.3630 0.1884 0.0696 0.0247 0 0.0008 0.0000 0.0000 0.0000 Cl 0.0397 0.0231 0.0000 0.0000 Zr 0.0001 0.0000 0.1276 0.1281 Gaseous Molecules H 1.0298 1.1159 1.2335 1.2563 H1O 0.0179 0.0056 0.0000 0.0000 0H 0.0040 0.0003 0.0000 0.0000 HCl 0.1804 0.2112 0.0009 0.0000 ZrO 0.0026 0.0000 0.0108 0.0089 ZrCl: 0.0099 0.0030 0.0942 0.0947 Liquid and Solid Molecules ZrO;(1) 0.7080 0.7178 0.5627 0.0000 ZrO,(s) 0.0000 0.0000 0.0000 0.5636

Table 11 shows calculated performance data including the specific impulse for an illustrative ratio of reactants in the propellant system ZrH NH CIO HClO 211 0 HNO H 0.

TABLE 11 Ingredients: moles gl 1 00g ZrH, 1.0189 72.092 Nl-1 Cl0 0.04255 3.794 HC10 21-1,) 0.26930 20.310 HNO; 0.05302 2.536 H2O 0.09274 1.268 Computed Density g/cc 3.156 Performance: Shifting 1 sec 193 Shifting Volumetric 1., lb-sec/in. 25.5 Thermodynamic Characteristics: Chamber Exhaust Temperature, "K 4718 3 3 37 Moles of Gas, moles/100g 1.7128 1.6906 Combustion Products, moles/ 100g Gaseous Atoms H 0.2128 0.17 27 Cl 0.0191 0.0187 0 0.0005 0.0001 Gaseous Molecules l-lCl 0.1632 0.1930 Hg 1.2001 1.2322 ZrCl; 0.0270 0.0125 H1O 0.0491 0.0240 OH 0.0046 0.0009 N, 0.0363 0.0363 Liquid and Solid Molecules ZrO,( 1) 0.7463 0.0000 Zr0,(s) 0.0000 0.7608

Table 111 shows calculated performance data for an illustrative ratio of reactants in the propellant system Zr N2H5N3 2H20.

Temperature, K 3579 Moles of Gas, moles/100g 3.9223 Combustion Products, moles/100g Gaseous Atoms H 0.1731 Cl .0.01 18 Gaseous Molecules H, 1.4122 HCl 0.1452 N, 1.1800 Condensed Phases ZrO, 0.4720

Table IV shows calculated performance data for three illustrative ratios of reactants in the propellant System N2H5N3 TABLE IV lngredients: moles g/lOOg moles g/lg moles g/100g Al 1 19.615 1 15.842 1 11.310 N H N 1 54.584 1 44.085 1 31.472 HClO '2H O 0.26 25.801 0.5 40.073 1 57.218 Computed Density, lb/in. 0.05874 0.05930 0.05999 Computed Density. g/cc 1.6258 1.6413 1.6604 Performance: Frozen 1 sec 273.1 266.1 249.4 Thermodynamic Characteristics: Chamber Chamber Chamber Temperature, K 3312 3391 3260 Moles ol'Gas, moles/100g 4.2981 3.9172 3.5343 Combustion Products, moles/100g Gaseous Atoms A1 0.0099 0.0002 0.0000 C1 0.0080 0.0187 0.0437 0 0.0001 0.0024 0.0126 H 0.1357 0.1181 0.0329 Gaseous Molecules 0, 0.0000 0 0006 0.0402 N, 1.8175 1.4679 1.0480 A1 0 0.0116 0.0001 0.0000 A10 0.0009 0.0003 0.0000 OH 0.0034 0.0574 0.1794 H 2.0515 1.1565 0.1883 HCI 0.1810 0.2748 0.3751 H1O 0.0785 0.8202 1.6139 Condensed Phases A1 0 0.3465 0.2933 0.2096

moles g/lOOg Computed Density, lb/in. Computed Density, g/cc Performance:

Frozen 1 sec Thermodynamic Characteristics:

Chamber Temperature. "K 3721 Moles of Gas,

moles/ 100g Combustion Products, moles/ 100g Gaseous Atoms H 0.2635 Gaseous Molecules A1,0 0.0379 A10 0.0062 OH 0.0186 H, 1.5797 HCl 0.2594 H=O 0.1395 N1 0.9879 Condensed Phases Table VI shows calculated performance data for an illustrative ratio of reactants in the propellant system Zrl-l LiClO HC1O 21-1 0.

TABLE VI Ingredients: moles g/lOOg ZrH; 1 66.557 LiCIO 0.08763 6.656 HC1O 2H,O 0.2749 26.787 Computed Density, lb/in. 0.1 193 Computed Density, g/cc 3.3015 Performance: Shifting 1 sec 190 Shifting Volumetric 1 lb-sec/in. 22.667 Frozen 1 sec 190 Thermodynamic Characteristics: Chamber Exhaust Temperature, "K 4073 2960 Moles of Gas, mole/g 1.5228 1.4715 Combustion Products, moles/100g Gaseous Atoms H 0.2653 0.1714 Li 0.0093 0.0190 C1 0.0293 0.0207 Gaseous Molecules 2 0.9675 1.0140 HCl 0.1346 0.1779 LiCl 0.0533 0.0435 ZrCl1 0.0208 0.0083 H O 0.033] 0.0152 OH 0.0078 0.0013 ZrO; 0.0008 0.0000 Condensed Phases ZrO2( 1) 0.6921 0.4945 ZrO (c) 0.0000 0.21 10 Dihydrated perchloric acid is an intrinsically stable, only slightly toxic and caustic, oxidizer containing 73.6 percent perchloric acid and 26.4 percent water. The oxidizer is a water-white liquid with a density of 1.713 g/cc at 25 C, boiling at about 200 C and freezing at 20 C. The dihydrated acid is not even slightly caustic when cold which makes it safe for personnel and it does not require special equipment for handling.

When a lower freezing point is required for the liquid oxidizer water and/or nitric acid may be added. Both water and/or nitric acid lower the freezing point of the perchloric acid dihydrate. Water, however, lowers both the density and impulse of the oxidizer while nitric acid alone will lower the density. On the other hand, if high impulse is required and high density is of lesser importance, a higher proportion of nitric acid may be used. The addition of both water and nitric acid to the perchloric acid dihydrate makes it possible to provide oxidizer compositions having selected combinations of density, impulse and freezing point to meet a variety of requirements. The nitric acid content may be as high as 15 percent but in general compositions containing not more than about 10 percent of nitric acid are preferable as they are not unduly corrosive and are safer to handle.

The liquid oxidizer compositions of the invention consist essentially of from about 59 percent to about 77 percent by weight of perchloric acid, from 0 to about percent by weight of HNO and the remainder water, the amount of water being sufficient to form dihydrated perchloric acid with at least about 95 percent of the perchloric acid content.

The following compositions have provided very satisfactory results:

I. 93 percent dihydrated perchloric acid (DHPA), 6

percent nitric acid and 1 percent water.

2. 90 percent DHPA, 8 percent I-INO and 2 percent 3. 84.2 percent DI-IPA, 10.5 percent I-INO and 5.3

percent H O.

Table VII shows densities of I selected dihydrated perchloric acid-water-nitric acid compositions.

The improved oxidizers of the invention may be advantageously employed with a wide variety of light metals, metal hydrides, mixtures of light metals and metal hydrides, and light metals and metal hydrides admixed or combined with other compatible fuels. The following list is exemplary of suitable fuels which may be employed with the oxidizers of the invention: Zr; Al; a; z; g; g( 4)2 3)2 3; 3)2 2 H TiH and MgI-I Of these fuels Zr, ZrH and All-I have been found to be particularly suitable for rocket fuels with the oxidizers of the invention.

We claim:

1. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising substantially dihydrated perchloric acid and a fuel selected from the group consisting of light metals, metal hydrides and mixtures thereof.

2. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer compris ing substantially dihydrated perchloric acid and a fuel consisting predominantly of a light metal.

3. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising substantially dihydrated perchloric acid and a fuel consisting predominantly of a metal hydride.

4. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising substantially dihydrated perchloric acid and a fuel consisting predominantly of Zr.

5. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprisconsisting predominantly of AlI-I 7. A method of pro ucmg thrust which comprises reacting in a combustion chamber an oxidizer comprising a liquid composition consisting essentially of from about 59 percent to about 77 percent by weight of perchloric acid, from 0 to about 15 percent by weight of I-INO and the remainder water, the amount of water being sufficient to form dihydrated perchloric acid with at least about 95 percent of the perchloric acid and a fuel selected from the group consisting of light metals, metal hydrides, and mixtures thereof.

8. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising about percent by weight of dihydrated perchloric acid, about 8 percent by weight of nitric acid and about 2% by weight of water and a fuel selected from the group consisting of light metals, metal hydrides, and mixtures thereof.

9. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising about 84.2 percent by weight of dihydrated perchloric acid, about 10.5% by weight of nitric acid and about 5.3 percent by weight of water and a fuel selected from the group consisting of light metals, metal hydrides, and mixtures thereof.

10. In a rocket propellant system a liquid oxidizer consisting essentially of from about 59 percent to about 77 percent by weight of perchloric acid, from 0 to about 15 percent by weight of HNO and the remainder water, the amount of water being sufficient to form dihydrated perchloric acid with at least about percent of the perchloric acid.

11. In a rocket propellant system a liquid oxidizer consisting essentially of about 90 percent by weight dihydrated perchloric acid, about 8 percent by weight nitric acid and about 2 percent by weight water.

12. In a rocket propellant system a liquid oxidizer consisting essentially of about 93 percent by weight dihydrated perchloric acid, about 6 percent by weight nitric acid and about 1 percent by weight water.

13. In a rocket propellant system a liquid oxidizer consisting essentially of about 84.2 percent by weight dihydrated perchloric acid, about 10.5 percent by weight nitric acid, and about 5.3 percent by weight water.

Claims

2. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising substantially dihydrated perchloric acid and a fuel consisting predominantly of a light metal.

5. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising substantially dihydrated perchloric acid and a fuel consisting predominantly of ZrH2.

6. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising substantially dihydrated perchloric acid and a fuel consisting predominantly of AlH3.

7. A METHOD OF PRODUCING THRUST WHICH COMPRISES REACTING IN A COMBUSTION CHAMBER AN OXIDIZER COMPRISING A LIQUID COMPOSITION CONSITING ESSENTIALLY OF FROM ABOUT 59 PERCENT TO ABOUT 77 PERCENT BY WEIGHT OF PERCHLORIC ACID, FROM 0 TO ABOUT 15 PERCENT BY WEIGHT OF HNO3 AND THE REMAINDER WATER, THE AMOUNT OF WATER BEING SUFFICIENT TO FORM DIHYDRATED PERCHLORIC ACID WITH AT LEAST ABOUT 95 PERCENT OF THE PERCHLORIC ACID AND A FUEL SELECTED FROM THE GROUP CONSISTING OF LIGHT METALS. METAL HYDRIDES, AND MIXTUES THEREOF.

8. A method of producing thrust which comprises reacting in a combustion chamber an oxidizer comprising about 90 percent by weight of dihydrated perchloric acid, about 8 percent by weight of nitric acid and about 2% by weight of water and a fuel selected from the group consisting of light metals, metal hydrides, and mixtures thereof.

10. In a rocket propellant system a liquid oxidizer consisting essentially of from about 59 percent to about 77 percent by weight of perchloric acid, from 0 to about 15 percent by weight of HNO3 and the remainder water, the amount of water being sufficient to form dihydrated perchloric acid with at least about 95 percent of the perchloric acid.