DE1539339A1 - Gas pipes, in particular for use as energy storage, and methods for operating the same - Google Patents

Description

United States Atomio Energy Gommiesion

Germantown, Maryland

Gas pipes, in particular for use as energy storage, and methods for Operation of the same

Priority is claimed based on patent application USA Ser.No. 480 664 of August 18, 1965

The invention relates to gas tubes and more particularly to | on a method for operating a gas pipe as thermoionigchei Energy converter that contains a gas or metal vapor source.

A thermionic energy converter is an electron tube with a cathode and an anode for the conversion of Y / poor energy at the cathode to electrical energy in Sorrn ** a tension generated by the drill itself between their cathode and anode connections. The materials of the cathode and the anode are usually chosen so that a cathode is obtained whose electronic work functions much higher than that of the anode is to one

BATH ORIGINAL 909845 / CU 31

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internal electric field to accelerate the electrons to generate from the cathode to the anode »

So that the movement of electrons from the cathode to the anode is facilitated, the space charge of the electrons can between The cathode and the anode can be neutralized through the use of positive ions · As a source of such ions An alkaline metal vapor, which has a low ionization potential, such as cesium, which is present in the room can serve is inserted between the electrodes "

A well known way of introducing an alkali metal vapor like cesium in the space between the electrodes requires the placement of a liquid alkali metal bath in the tubular vessel. This bath of liquid is usually in. one connected to the electrode space In the appendix of the tube vessel,

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A significant disadvantage of using one Fluid storage or bath lies in the fact that the Device is made undesirably temperature sensitive · It is well known that steam duck e.iiies liquid bath of alkali metal, which is used as a source for

ο Alkali metal vapor is used to provide the necessary positive

eo .., ■

“Generating ions, mainly through the bath temperature ** · ■ ■.

. £ determined 1st. The relationship between the vapor pressure and. 'jj ^ the bath temperature, hereinafter referred to as normal ■ condensation- ♦! »Temperature is called, is common to most elements

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known. (See, for example, K.K. Kelley, Bureau of Mines Bulletin 383, 1935).

With this in mind, the invention aims to create a improved gas pipes and a method of operation

■ ■ - ■ - ■■ '■■■ ..:' ■ '""'. ■ - ■ * "■

such a gas pipe, which is characterized by a lower temperature sensitivity of the gas or vapor pressure in. of the tube ' ^:

Is is common among thermionic energy converters such conditions to operate that most if not all metal surfaces in the vessel of the device with ■ a monomolecular layer covered by cesium or less. For example, the cathode with a half monomolecular layer of cesium coated »This coating of the inner metal surfaces of the device is in a state of equilibrium between an incoming and an evaporating amount of cesium on these surfaces.

The invention provides for this "tendency of the cesium, metal surfaces to exaggerate, to take advantage of »by means of proportionate large surface area provided in the device on which cesium is stored in its vapor phase

Φ will «/ These tanks can have a metal sponge that

*** Contains pores, and for example by sintering together jj, Wolf rainmetal te £ b tien or other material such as aluminum oxide

■ S .. ■■ "" "■■" -; '- ■ - "' ■" ■ '"■ -" ■'. . ■ ■ .- ■■■■ '

e »can be formed. The 'sponge. cannot take the form of a

ν sintered: have powder. For a given volume this ^; 3-ebild-it is the surface of the pores contained in it · - / "■"

153933t

relatively large, so that the storage of a relatively large amount of cesium is allowed in its adsorbed state. ■

: The greater affinity of cesium for other surfaces as liquid cesium does it. possible in the device cesium in an adsorbed state in a relatively to save a wide temperature range · This temperature range extends from a temperature slightly above the normal condensation temperature of cesium up to one much higher temperature at which the converter can be operated. With; other words can be a temperature at which the cesium pressure is most favorable for the best efficiency of the converter can be used, even if they is significantly higher or lower than one or more elements of the transducer.

This largely increased independence of the storage temperature of the Zäsiumdruck in the converter is · due to the fact that the binding energy of Zäsiumatomen at a bath is relatively small _t is about 0.75 electron volts at a temperature of 55O ⁰ C, while the binding energy of Zäsiumat'omen to the pore wall of the sponge is relatively large, for example 2, oo electron volts at the specified temperature. Therefore, with a sponge-type cell accumulator, it is possible to operate the accumulator at a noticeably higher temperature than normal.

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. A cesium vapor storage therefore turns out to be less dependent «on critical temperatures as storage in the form of liquid baths ·

A cesium storage device, as described here, stores cesium in the form of a material that is adsorbed on metal surfaces Steam. The volume of this type of storage is considerable larger than the reservoir according to the type of a liquid bath for the same amount of cesium. However, that should be considered as adsorbed Steam stored cesium volume sufficient over a normal operating life of the device. In this connection it should be mentioned that inevitable cesium losses occur during the operation of a converter * Causes for these losses can be grain boundaries, gaps or cracks in the inner wall of the vessel of the device the cesium can penetrate. It has been found that these losses occur during the normal life of the device be fully compensated if the surfaces of the forum walls of a spongy cesium vapor storage at least ten times the size of the normal inner surface of the transducer vessel. Preferably, however, the ratio of The pore wall surface must be considerably larger than the normal inner surface of the vessel. .

<° An embodiment of the invention is below with

OO ■. - -

^ Described in detail with reference to the drawing; in this

ο shows: ■ - -:

W Fig. 1 is a section of an Itermoionic energy converter »

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in which the invention is realized, and "

Pig, 2 a Schär curves of the operating pressure as a function van der Temperatur, which shows the considerable difference between the vapor-temperature relationships of liquid cesium reservoirs and sponge-like cesium vapor storage systems "

The invention is shown in the drawing on a thermionic Energy converter tube 10 shown, which is a vacuum-tight Vessel 12 hatι contains the cesium and consists of two identical circular metallic plates .14, 16, for example Tungsten is formed. The plates 14, 16 are suitable Distance from each other by a ring 18 made of insulating material held like aluminum oxide.

On the inner surface of the plate 14 is about by sintering Die 20 attached, which consists of sintered together tungsten particles can be made. The sintered die 20 forms a store for cesium vapor »on the surface of the die 20 see a relatively thin "stoke 22 of high-grade metal such as tungsten, which is attached to the die 20 is fixed about by sintering. Die 20 and the Layer 22 can form a cathode, and plate 16 can , serve as anode def device · A, pipe socket 24, the

φ expanded, serves as a means for that

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φ evacuating the vessel 12 and introducing the cesium into

m the same. :

. «· * - ■ - ■■: ■ ■■. i- - ■ ... ■ -. .

■ # *. ■■■■■■■■ .. ■ · :: ■■. ■■ ■ ■■. ■ :. .- ■■■. ■■■

1539333

The anode 16 »which is at a lower temperature than that Cathode is held, is held by radiators 26 in a suitable Way chilled. Me. Cathode can - by suitable means be heated, for example, by a flame which is applied to the outer "Surface of the plate 14 carrying the * cathode is directed, as indicated by arrow 28. The output power can be taken from the converter via lines 30, 32

In order to provide an effective store for adsorbed cesium over the whole practical "life-time" converter is to get it is desirable that the metal matrix or the sponge storage ■ has pore walls with a large surface area, so that it has such a Amount of adsorbed cesium atoms which is large in proportion to the number of cesium atoms in a normal . '■■ working transducer-10 is »It was found that a practical converter at least ten times as many cesium atoms should have on the pore walls of the Sohwammpeicher, how are present somewhere in the vessel of the transducer during normal operation of the transducer, but there is a larger ratio than 10tt- for the number of those in the store adsorbed cesium atoms, as they are somewhere in the transducer vessel, preferable, so can if space adjustments that formed by the die 20 are available

co memory must be large enough to hold a thousand times as many cesium atoms

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M>, as usually somewhere in the converter housing

Often ■ - ■ ^:

5 * 12 are available in the company. In this way, Bormale become

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.Cesium losses from the vessel 12 during the converter operation refilled by the memory over a period of time, the up to "the -.- limit, the normal life of a practical converter and beyond that »

It is possible to change the volume dimension of the cesium spike serving die 20 to cut to the tree in the transducer. It has been found that the size of the metal parts is sufficient which the storage matrix is composed, affects the volume of the matrix. So when the particle size is reduced becomes the volume of die 20 for a given Storage capacity also reduced. .

If a metal body according to the invention, such as the die 20, has the ability to spew on the surface of its pores x ^ times oO much 2esiumatoiMi, as are present in the tree of the transducer, at a vapor pressure of 1 Torr the following equation can be expressed *

^ ^Vq1 * ^ Oberf l.

here 5x10 ^ means a gas locality

d is the diameter of each metal piece of the Memory, assuming that each particle is spherical, and.

% ο1 * ^ ^ ^e surface - 2ahl the Zäsiumatome in your

; - ■ - "..; '· folumen - or - on the inner surface

aes -wandlere. "« ■ / '. ■ -; - .. ■■■. SAD ORIGINAtIA ^ \ Qm ^ it

From the above it follows that the volume of the spongy Die 20 depends on the office knife of the metal particles

of the sludge as indicated by the expression (1) · Therefore, can by choosing a special particle size for the die 20, the volume of the sponge to the space requirements of the respective * Converter type to be tailored »

For example, if the combined areas of the anode 16 and the metal structure of the plate 14 and the cathode 22 are -100 cm and the distance between the anode 16 and the cathode 28 is 0.025 cm, then the transducer can do two things pick up a sponge 20 which has a volume of 1 cm. For this volume of Sehwammes 20 a Speichorkapazität can be detected for Zäsiumatome * to that of one hundred times the internal volume and der.inneren surface of the transducer is provided that jder Durchmesserjäer is the sponge-forming particles ^10/1 Om and the converter at a steam pressure operated from 1 Torr.

The storage of cesium by surface adsorption on the porous walls of the sponge reservoir of the die 20 results in the possibility of a desired cesium vapor pressure of, for example, 1 torr in the Y / andler maintain, with a considerably lower Temperature dependency than in the case of the converter with Zägium bath * The curve 34 in FIG. 2 shows the vapor pressure as a function of γοη the temperature T_ of a cesium reservoir in the form of a Badeia * Es it should be noted that this curve is quite steep, that is to say that

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a change in temperature control undesirably causes a relatively large change in pressure. This is because the force with which the cesium atoms are bound to the bath is relatively small, corresponding to a binding energy of only 0.75 electron volts pore walls of a memory is \ 20 stored by Metailsohwammtyp, is much less steep and thus the Zäsiumdampfdruck desirably less changes for the previously mentioned change · in (temperature control This is because the force with which the Zäsiumatome in the memory of the pore walls of the same are bound, is much higher than in the case of a memory in the form of a bath, that is, corresponding to a binding energy of 2 electron volts

If the cathoderite temperature is 3 ° _K , there are considerable deviations from this! Temperature either! to the left (in fig «2)

■ - ■; ■■ ■ ..- .. ·} "- to a low temperature I ^ or n ^ oh right to a higher Temp'erattr T ^ permissible if the sponge storage of the invention is used without the vapor pressure of the cesium in the transducer ve »deviates considerably from a value such as 1 for r · This allows unavoidable fluctuations · in the cathode temperature of the converter without reducing the efficiency of the converter»

the temperature.T in lig »2 is the temperature of the anode 16 of the figure, 1 * kwin obviously the storage in heat transfer in relation to the anode 16 instead of the cathode 22,

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to maintain a desired cesium vapor pressure of 1 torr obtain. The pressure can vary depending on the temperature then behave ^ as shown by curve 38 in Pigφ 2. This makes it possible to use the sponge feeder for gas after the Invention to use either on the cathode or on the anode »It is also possible / the cesium storage on the converter vessel to be arranged in an area away from the anode and the cathode *

When two or more separate sponge tanks are used » then intricate pressure-temperature relationships are obtained, than in Pig. 2 · Indeed, there is a greater degree of freedom -at; the. Choice of a desired relationship possible.

The Bindungeeiiergie the Zäsiumatome on the pore walls of the sponge memory 20 is, as indicated above, such as 2-electron "- volt at a temperature of 553 ⁰ K. Doen the binding energy of the Säeiumatome with the Zäsiumüberzug · So 1st changes at higher coating reduced the Bindungseniergie, while & ei smaller coating the Bi dungaenergie increase is · lall each is Orusi: - 'certain temperature, such as the following expression -cirtt ■ -' by the ■ ■■ "; ■ ■: ■ ^_: -.. '.'"■' · .-' ■ - ■,

(2)

hiarin. means - - - -

T _y aie siidation energy of. Cesium atmosphere, T ^ lie-temperature "of the element, at which α = r sponge storage

■; ■■ ■ --- ^e - ^r ^ - ^is »,;. 90984570438

p the vapor pressure and

Not a constant that varies slightly with temperature changes.

To ensure a predetermined working temperature. If it does not extend over the temperature range in which a desired cesium vapor pressure is to be maintained, it is preferable that this predetermined working temperature forms a mean value T 1 between the limits T 1 and T _{1 of the} ranges, as in Pig. 2 is shown. In this way, temperature deviations above and below the mean or predetermined working temperature are permitted without influencing the cesium vapor pressure

In the manufacture of a thermionic energy converter 10 (Fig. 1) with a "tungsten sponge storage for cesium is a Sponge-mass 20 of such volume "that it can be attached to the walls of the forums at least ten times as many carbon atoms adsorbed as on their surfaces absorbed by metal elements 4ee Wahdlergefäßee 12 A. and are present in the space delimited by the slope » attached to end wall 14, such as by sintering, to form part of the cathode of the device. The cathode should be a have a highly smooth surface opposite the anode 16, im

With regard to the relatively small distance between the Gegenco

opposite surfaces of the cathode and anode * This smooth surface area can be achieved by Sihicht 22 of tungsten or other overall ■ m
- ^ suitable metal are formed, which have a thickness of about 10

♦ * ■ has a thousandth of an inch and is on the surface facing the anode 16 of the sponges 20 is applied »the exposed side of the thin 22 will ~ lai; t "remacht. Duxdi · PGei ^ neto ^ polishing cf-rr

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and is therefore suitable for increasing the effective cathode surface of the Form device. When the layer 22 is applied high, the surface of the sponge 20 towards the anode 16 should be more suitable Way to be polished

The Iaolierring 18, which has a length or height that a desired abatand is provided between the mutually aligned surfaces of the cathode 22 and the anode 16, which can be 0.025 cm in the case of a converter type, is expediently metallized on its end faces and approximately duroh solder attached to the end faces 14, 16 of the transducer.

Subsequently, the vessel 12 is evacuated through the pipe socket 24 to a desired, relatively low pressure. The converter vessel 12 and the electrodes 16, 22 are then brought to working temperatures. The vessel temperature can be 553 ⁰ Hb. The fence is let into the vessel 42 'through a suitable slope - which is also heated to this temperature. Such an appendix is generally known and is therefore not shown. The annex contains a fence bath. Ea is important hen the operation of the thermo ion Yes) energy Wandlere 10, that the entire "Walk * ¹ over the Zäaiumbades is operated at a temperature · After equilibrium is established, for example, a Zäsiumto

ο vapor pressure of 1 Torr in the vessel, the appendix is roughly through

· *** Pinch off, hermetically sealed. In such a 51eichg # wiohts-

^ ₄ state, the cesium forms a partial monomolecular layer on the cathode surface 22 and on the pore walls of the tungsten

6i :. ^:

* ° schwamms 20. Its monomolecular layer of cesium is placed on the

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1538339

Häche the cooler anode 16 formed · Zäsiumatome penetrate the interior de * vessel 12 · Eiist important to the operation dee converter 1O _t that the whole transducer Pies is operated at temperatures above the normal Kondensationetemperatur corresponding to the working pressure * ensures that Heine liquid Zäaiumbäder somewhere in the converter and that the pressure is controlled at all times by the temperature of the sponge reservoir.

Ea is o-mi1 worthy of the fact that at any selected operating temperature the SchwMHMpeicher for cesium functions as a permanent source of cesium, to da | is affecting normal ZÜsiumverluste in the Qeiäfl not IiebenedaUii ¹ of the apparatus, furthermore, the btechriebent achwammepeicher less dependent on Tenperaturetabilität Ait for maintaining a desired steam pressure as a storage ^v oher with

efficiency at

Bath and therefore guarantees a higher work *

moderately wide outside area »

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Claims (1)

Pat e ρ t a η a ρ r ü c h e 1.) Thermionic gas tube, especially for use ala energy converter, whose vessel has a cathode and a Anode »of which the cathode has a much higher electronic working funcion than the anode, as well Contains alkali metal vapor which forms positive ions 'ale'. neutralize the space charge between cathode and anode, characterized in that as a steam storage tank in dim only a surface storage in the form of a pore or sponge body for at least ten times as much steam atoms, it is usually present somewhere in the vessel is" 2 ») Procedure for A operation of a GasrÖhri respectively an energy converter according to claim 1, characterized in that it that only on surfaces in the vessel at a temperature above the normal condensation temperature of the vapor at least ten times as many steam atoms as usual in the vessel are present, are stored, and the tube with all its parts at temperatures above the normal condensation stone temperature is held * 9 09 BATH ORIGINAL 1S3933I ° - heated 3.) Method of operating a gas pipe with a sponge-like Gas storage in the vessel that contains gas of a predetermined pressure at a given temperature, the higher than the normal condensation temperature of the gas, characterized in that the memory is heated to a temperature which is substantially higher than the given temperature is.t, while the predetermined gas pressure in the vessel in the essential is preserved 4 ·) Procedure for operating a metal vapor tube, whose Electrode chamber metal vapor from normal condensation, contains temperature at a given pressure and with a memory for metal vapor of relatively large surface area is in communication, characterized in that all parts of the tube including the memory on one Temperature above the normal condensation temperature. ·. 5 x} method of operating a thermionic "energy converter, which includes cesium vessel and a porous sponge memory for cesium, characterized in that the _transducer} to a vorbeatim. te ^I 2erj: tr>: -. ti.r above the normal condensation temperature of cesium at a given pressure 6 «) Procedure for operating a thermionic energy ** 4- "'transducer, the zoium and a surface spear for * Contains cesium »-marked that the transducer is on : '■■ * ■ : ■■■■ a predetermined temperature above the condensation temperature of cesium is heated at a given pressure, at least ten times the number of cesium atoms are adsorbed on the surfaces of the memory as are present in the transducer outside the memory, and the memory to a temperature higher than that is a predetermined temperature, is heated in order to free cesium from the reservoir, this higher temperature having a different pressure-temperature relationship than the predetermined temperature and the given pressure. 7.) A method for operating a thermionic energy converter according to claim 6, characterized in that the Pressure in the pressure r-temperature ^ relation essentially is the same as the given pressure. 8.) Method for operating a thermionic energy converter, the vessel of which is cesium with a predetermined vapor pressure at a given temperature, characterized in that cesium is supplied to the vessel from a source for adsorbed cesium in the vessel is released only at a temperature higher than that for the predetermined Pressure is required temperature. ■ 9 «) method for operating a thermionic energy; converter containing cesium, characterized in that the cesium is heated to such a temperature, a predetermined vapor pressure .that cesium for the operation 'is generated, and this vapor pressure with changes in the' _ ■ '- is maintained temperature substantially constant . ■ BADOF8GINAL . ■ "- 4 * - ■■■■■" ■ - J? 10.) A method for operating a thermionic energy converter containing cesium and its cathode Includes sponge storage for cesium, characterized in that the transducer is above a first temperature the normal condensation temperature of cesium in a is heated to a predetermined pressure and the cathode is heated to a temperature different from the first temperature without changing the predetermined pressure, the cathode in a relatively wide temperature range can be operated without a significant change in pressure in the converter in order to increase the efficiency of the converter. 11.) A method for operating a thermionic energy converter containing cesium ', characterized in that the converter to a first temperature ü'oor ΐ.3ΐ- normal Condensation temperature of the cesium 4 is heated to achieve a given vapor pressure, a cesium storage in the wadjaler to a temperature above this first temperature heated and cesium is released from the memory into the transducer, with the released cesium losses Cesium from the transducer is replaced by the given vapor pressure to hold at the first temperature. '■ ■ to converter 12.) The method of operating a thermionic energy containing cesium and a memory for cesium, *! .- ": ■■■ - .. ■■■■.: ■ -... ■■". ■ '- ■. ■ - ■■ ty_ \ characterized in that the converter including the YY-. Memory to an initial temperature above normal to condensation temperature of the cesium is heated at a given pressure, using cesium on surfaces of the memory 1533333 a binding force that is only significantly above to give in to the first temperature lying vej>. like, wherein the memory can be heated to a temperature which is substantially different from the temperature mentioned is while the given pressure is essentially held * 13.) Method for operating a thermionic energy converter which contains cesium and an electrode and a ■ Cesium reservoir with a relatively large surface Contains heat transfer to the electrode, characterized in that the transducer and the memory at a temperature heated above the normal condensation temperature of cesium in order to obtain a predetermined vapor pressure, wherein the memory the cesium in a temperature range of the said first temperature up to a substantially above the sweeping temperature and the cesium in the transducer ' outside of the store a normal pressure-temperature dependency has, while the cesium in the memory has a smaller pressure-temperature dependence than the normal dependence and wherein the electrode is at a temperature can be heated, which is much higher than the first temperature with a smaller than normal pressure dependence is in the converter. · 14.) Process for the operation of a thermionic energy converter, whose vessel is Zäsiufiadampf and a sponge reservoir '; for cesium, characterized in that cesium atoms ..- are stored in the vessel with a binding force which is greater than the force i st required for the purpose of releasing cesium- BATH Atoms are overcome from storage at an initial operating temperature above the normal condensation temperature of cesium can be, which is significantly higher than said first temperature, the pressure of the cesium in the Vessel is kept essentially constant in the event of significant changes in the operating temperature of the converter. 15.) Method for operating a thermionic energy converter, its vessel has a cathode, cesium vapor and a fjhw ^ mmspeicher for cesium with heat transfer to the cathode • contains, characterized in that the V / aqnler on a. Operating temperature above the normal condensation temperature of cesium is heated to. a predetermined vapor pressure and in the sponge store at least ten times as many cesium atons as in the vessel "outside the spongy cavity .- 's vcrh-atider, with a binding force that is essential ^ i. grckor to be saved as the- 'of a companion that is, where the kuritcdei »significant deviations from this operating temperature is able to trust without influencing the predetermined double pressure;,; er / lich, and the memory cesium loss: > t ~! from ae: .. j ^ fuii over a provisionally long operating time des / ancllers to add verr-iag » ^ - .. Pur the applicant: ^, Bremen, the 12th ^: 7.196u 'Patentanwälte ^ cn applicant; - United BtateR Atomic Dipl.-Ing. Hans Meissner ^ Energy Commission. Dipl.-Infl. Erich BoUe "Fc Germantown, Maryland . . 28 Bremen U> Sievogtstraße21, Teleten302172 qo priority is claimed due to Patent Application-USA Ser ... o, 480 664 by t £, Aurv.st Tjtp BAD ORiÖiNÄL