US2028946A

US2028946A - Gas generator

Info

Publication number: US2028946A
Application number: US404310A
Authority: US
Inventors: Niconoff Dimitry
Original assignee: Phelps Dodge Corp
Current assignee: Freeport Minerals Corp
Priority date: 1929-11-02
Filing date: 1929-11-02
Publication date: 1936-01-28
Anticipated expiration: 1953-01-28

Description

D. NICONOFF GAS GENERATOR Jan. 28, 1936.

3 Sheets-Sheet 1 Filed Nov. 2, 1929 INVENTOR "l'ry NIconoFF HIS ATTORNEYS Dlml mxiii Jan. 28, 1936. NICONQFF 2,028,946

GAS GENERATOR Filed Nov. 2, 1929 SSheets-Sheet 2 Hi3 ATTORNEYS D; NICONOFF GAS GENERATOR Fild Nov. 2, 1929 3 Sheets-Sheet 3 ATTORNEYS Patented Jan. 28, 1936 UNITED STATES GAS GENERATOR Dimitry Niconoif, Glarkdale, Aria, axis-nor, by

mesne assignments, to Phelps Dodge Corporation, New York, N. Y., a, corporation of New York mputation November 2,1929, Serial No. 04,310

4 Claims. (on. 48-82) J This invention relates to gas generators and has for an object the provision of an efiicient apparatus for generating industrial gases. More particularly the invention contemplates the pro- 5 vision of an improved apparatus forgenerating reducing gases for use in metallurgical and simi-' lar industries. The invention further contemplates. the provision of improved apparatus for generating and utilizing gases. The heretofore customary type of gas generator is relatively complicated in construction and requires considerable space for its installation.

In view of this fact, it is frequently necessary to generate industrial gases at points remote from the points atwhich they are to be used. The

gases are usually stored under slight pressure at some point between the generator and the point of use, and when the operations being conducted require the introduction of the Eas under considerable pressure it is necessary to provide an additional compressor or blower. While industrial gases are usually produced at high temperatures, their heat content is dissipated while they are in storage or while they are being conducted from the storage receptacle to the place at which they are to be used. Consequently, not onlyis considerable heat wasted, but in some types of operations, such, for example, as those involving the introduction of reducing gases into a molten mineral bath, heavy deposition of carbon takes p)ace in the tuyeres interfering with the proper operation of the (apparatus.

. The present-invention contemplates the provision of gas generating apparatus which is highly emcient and of relatively simple construction and which may be conveniently disposed immediately adjacent a receptacle or other type of apparatus in which the gas is to be used. The invention further contemplates the provision of improved apparatus for subjecting materials to the action of gases at high temperatures in which gas may be introduced directly from a generator into a receptacle containing the material to 'be subjected to the actiono'f the gas.

Gas generators constructed in accordance wit the present invention are adaptedto be utilized in eflecting'partial combustion of carbonaceous materials and are provided with means for preheating'the oxidizing gas. In the preferred form of construction the gas generators are provided with combustiou chambers which are surrounded by gas chambers so arranged that the oxidizing gas. may bepassed around the combustion chamber and be heated by the ,heat radiated therefrom 55 during its passage into the combustion chamber. The combustion chamber is preferably cylindrical, and it is preferably so mounted that its axis extends horizontally. An outer casing surrounds A the cylindrical combustion chamber and is spaced fl therefrom to providea gas chamber for the ini I troduction and preheating of the oxidizing gas. A tube may extend axially through the-combustion chamber to provide means for igniting the combustible mixture in the first instance, and for providing an additional hot surface for the con- 5 tinuous ignition of the combustible mixture introduced into the combustion chamber.

The combustion chamber may be provided with one or more burners for injecting a mixtiu'e of carbonaceous material and oxidizing gas. Burners capable of injecting a mixtureof any desired carbonaceous material and any desired oxidizing gas may be provided. Thus, burners capable of .injecting a mixture of air and any suitable oil, qr burners capable of injecting a mixture of air and powdered coal may be employed. The gas generator'is preferablyvprovided with observation tubes having sealed end portions extending into the interior of the combustion chamber and open end portions projecting-outwardly beyond the outer casing. Such tubes permit the operator to determine the temperature within the combustion chamber by inserting a pyrometer or by observing the color of theheated sealed ends.

The arrangement of gas chamber, combustion 5 chamber, and burners is such that the air supply to all burners may be controlled by a single valve and the supply of oil or other carbonaceous material may, be controlled independently at each burner. In the complete apparatus of the invention the gas generator is mounted on or closely adjacent to a receptacle which is adapted to contain the material tome subjected to the action of the gas. The gas generator is preferably mounted on a 3 wall of the receptacle infsuch a manner that relatively short conduits or tuyercs may be used for providing means of communication between the combustion chamber-and the interior of the receptacle. The, respectacle may be stationary or it may be mounted for rotary movement through any desired arc, and when the receptacle is mounted for rotary movement the generator is preferably movable therewith. The portions of the tuyeres or conduits which are disposed between the gas generator and the outer shell of the receptacle may be covered with insulati material to prevent heat losses, or the' gas generator may be so mounted that the exposed portionsof the tuyeres or conduits are sufficiently short that the heat losses are negligible. This ar-' rangement of gas generator and receptacle permits the introduction of gases into the interior of the receptacle at temperatures and pressures substantially equal to those at" which the gases are generated.

In'one of the preferred forms of the invention, the apparatus consists of a receptacle'adapted to hold a molten mineral bath and mounted for movement about a horizontal axis, a reducing gas provided for introducing other fluid or solid reagents into the interior of the receptacle at any desired points.

The apparatus of the invention may be used to particular advantage in the treatment of siags and mattes and similar products resulting from r the smelting of ores containing zinc. in the treat- 1 ment of zinc-bearing materials; the receptacle is preferably a converter similar to those ordinarily used in copper smelting. The converter may be stationary, but it is preferabiy so mounted that it may be rotated-or tiltedabouta'horizontal axis a to permit charging and removal of the charge. The gas generator may be mounted on awall of the converter or it may be separately mounted junction which is shown one of the preferred embodiments i immediately adjacent the converter and attached thereto merely by means of conduits or tuyeres communicating with the combustion chamber and the interior of the converter.

In the treatment of zinc-bearing materials, reducing'gas is generated'in the-gas generator and injected directly into a molten bath of the zincbearing material beneath the surface thereof. The gases are introduced into the molten bath at temperatures and pressures substantialiy equal to those at which they are generated since the heat loss is negligible. Apparatus for treating zinc-bearing materials is preferably provided with auxiliary tuyeres for introducing air or other oxidizing gases into the converter at one or more above the of the bath to oxidize metallic zinc produced; and means are provided for collecting the resulting zinc oxide iumes.

The invention will be better understoodirom a consideration of the following description in conwith the accompanying drawings in of the invention, and in which Fig. 1 is an elevation partly in section of a gas generator constructed in accordance withthe invention; w Fig. 2 is a section taken substantially along line 2-2 of Fig. 1;

Fig. 2a is a sectionsimilar to Fig. 2, but show- 7 ing a modification in the burner to permit useot solidruels; and 1 provided with a combustion chamber l0 comprising a metal cylinder ll lined with a layer on. asbestos or other heat insulating andheat re- Fig. 3 isa elevation of a converter 'having a gas generator mounted thereon.

The gas generator shown in the drawings is irac'tory material l2 and having its ends sealed by means or circular metal closure plates or discs. ii. The longitudinal axis of the combustion chamber extends horizontally. Anouter cyiindrical metal casing ll surrounds the combustion chamber The circular closure plates I 2 are of greater diameter than the combustion chamber cylinder The outer. casing is provided at its ends with' flanges liwhich are attached to the peripherai edge portions of the closure plates; The combustion chamber cylinder H and ed in the opposite end wall of the casing 2| with nozzle 23 extends downwardly into the casing 2 modification in the burner assembly to permit -paratus shown in Fig. 2 have been omitted from an opeiing 53 in the cover plate 21, and projects ment therewith. The ignition tube l6 extends through central openings in the closure plates l3 and through stumng boxes "which permit expension andcontraction of the tube. The ignition tube I6 is formed of a suitable heat-resisting alloy. Brackets 20 are provided between the ends of the ignition tube l6 for supporting the tube and preventing sagging when the tube is heated to high temperatures. The. ignition tube it and the stuffing boxes I! are removable and 1 the openings in the closure plates i3 are sumciently large to permit easy access to the interior oi the combustion chamber to permit repairs to the lining.

A number of burners are'mounted in the wall 1 oi the combustion chamber adjacent the top.- Any desired number of burners may be used. The number of burners provided will depend upon the size of-the gas generator and the capacity of each burner. Each burner comprises a casing 2| having an open end portion extending into the combustion chamber. An air inlet nozzle 22 having a restricted discharge opening is mountits restrigted h rge. end directed toward the interior of the combustion chamber. An oil inlet to a point adjacent the restricted discharge opening 01' the air inlet nozzle 22. The oil inlet nozzle 23 is connected by means of a conduit 24 to a source of supply of oil under pressure (not shown). A valve 25 is provided for controlling the flow of oil to each oil inlet nozzle. The oil inlet nozzle is provided with a punching rod 26 for cleaning purposes. The burners are preferably so mounted that a fluid stream'issuing from the air inlet nozzle 22 is directed above the ignition' tube against the opposite side of the combustion' chamber. The outer casing I4 is provided with openings and'removable inspection plates 2! adjacent the burners to permit the insertion and removal of the burners. A single air inlet 30 which may be provided with a suitable control valve communicates with the interior of the air chamber i8 near the top therebf and adiacent the burners.- A partition 3| extends longitudinally of the air chamber l8 in contact with the'outer casing M, the combustion chamber cylinder II, and' the closure plates l 3.. The partition 3| is disposed at the top oi? the generator between the air inlet 30 and the; burners. and it serves to prevent air from pass; ingl'rorn the air inlet 30 .over the top of the; comb tion chamber to the burners. i

A number oi. gas discharge outlets 32 communicate the interior of the combustion ehambeii and'pass through the air chamber l8 to points outside the outer casing ll. Observation tubesl 33 extend through the outer casing and combustion chamber and across the ignition tube to points intermediate the lining and ignition tube. The observation tubes are preferably disposed, at points between the burners. Eachobservatlon tube is sufllciently large to perznit the insertion of a pyrometer. The inner-end of each tube is sealed. v

Fig. 2a, which is to Fig. 2, shows a the use of solid fuels. In this modification, the air nozzle 22 and the oil nozzle 23 of theapthe structure. .A fuel eonduit 52 passes through inwardly toward the combustion chamber l0 through the opening in the combustionchamber wall ll provided by the casing 2|. The fuel conduit 52 is supported in the opening 53 of the cover plate 21 by means of a plug 54, through a hole in which the fuel conduit extends, and to which the fuel conduit may be rigidly fastened, as by welding. A gas tight joint may thus be obtained. ,The plug 54 may be threaded and the normal bath level.

' shown).

screwed into corresponding threads on the cover plate, or may be otherwise attached thereto. k

A plumbers union 55, or other suitable link, connects the outer end of the fuel conduit to one end of an intermediate conduit 56, the other end of the intermediate conduit being connected to a. header pipe 51. The header pipe is suitably connected to sources of supply of powdered fuel and air (not shown).

By uncoupling the union and turning the intermediate conduit 56 out of the way, the cover plate 21 may be readily removed for inspection or other purposes.

Fig. 3 shows a combination-in which -gas generators, constructed in accordance with the invention, may be used to great advantage. In

the apparatus shown in Fig. 3 the gas generator is rigidly mounted on the side of a; receptacle of the type used as copper'converters. The converter comprises an outer metallic shell 34 lined with a layer of suitable heat insulating brick or other material 35 and a layer of heat refractory material, such, for example, as magnesite 36. The converter is mounted on rollers 31 for movement about a-horizontal axis. The gas producer is attached to and movable with the converter. The converter is provided with a number of tuyeres, as indicated by the numeral 40, which extend through the outer shell and the lining materials and the outer ends of which are attached to the gas discharge conduits 32 of the gas producer. The tuyeres d6 are attached to the gas discharge conduits 32 by means of I connections ii. The tuyeres enter the converter at points below the normal bath level. Nipples 32 having valves 53 mounted thereon are attached to the T connections 6! inaxial alignment with the tuyeres ill). The valves d3 may be manipu lated to permit the insertion of punching bars for cleaning the tuyeres. The air inlet 36 is connected to a header M which is suitably connected to a source of supply of air under pressure (not shown). Auxiliary air tuyeres d5 extend through the converter shell and lining and communicate with the interior ofthe converter at points above The tuyeres 15 are connected to a header it which communicates with a source of supply of air under pressure (not The tuyeres d5 are also provided with valves M which may be manipulated to permit the insertion of bars for punching purposes.

A pilot burner 56 is removably mounted in the ignition tube It and may be utilized for starting the operation of the gas generator. Removable plugs may be provided for closing the ends of the ignition tube when the gas generator is in by heating the ignition tube 46 by means of the pilot burner 50. A pilot burner may be inserted in the ignition tube at each end. Heat from the ignition tube is radiated to and heats the insulating material on the wall of the combustion chamber. Heating is conducted in'this manner until the temperature of the combustion chamber wall is at least equal to the ignition temperature of the air and oil mixture to be introduced.

Air and oil are then admitted in proper propor-' tions to, provide a reducing gas having the desired qualities. The air is heated in passing around the combustion chamber from the air inlet opening in the. gas chamber to the air inlet nozzles. The burners admit the air and oil in the form of a mist in which the air and oil are intimately mixed. The intimate mixture of heated air and oil enters the combustion chamber between the heated walls of the ignition tube and the combustion chamber and it is immediately ignited. The resulting gas passes through the tuyeres 40 directly into the converter at a temperature substantially equal to that at which it is generated. Proper control of the quantities of air and oil will result in partial combustion of the compounds contained in the oil with the resulting production of a gas mixture containing stantially the same manner in case solid fuel is to be used as in the case where oil is the fuel.

In such an event a modified burner such as the one illustrated in Fig. 2a is employed.

Powdered coal, or other solid combustible carbonaceous material suspended in a current of air or other oxidizing gas is supplied to the header pipe 51 from a suitable source and from there is blown through the intermediate conduit 56 and the fuel conduit 52 into the interior of the combustion chamber I 0. As in the case where 011 is used as a fuel, a pilot burner 5|) is inserted into the interior of the ignition tube, and the ignition tube, thus heated, causes the ignition of the powdered fuel in the combustion chamber. Air in insufficient quantity to cause complete combustion of the fuel is admitted. Substantially all of the air necessary may be admitted with the powdered fuel as a suspension medium therefor but preferably the least amount of air capable ofefiiciently transporting the powdered fuel is introduced in this manner, and additional air is admitted through the air inlet opening 30, passed around the combustion chamber Ill, and conducted into the combustion chamber through the annular space between the cas- 7 In addition the effluent gas will contain some hydrocarbon gases (distilled from the fuel), considerable quantities of nitrogen (if air is used as the oxidizing gas) and some fine solid particles of ash. Since the'efliuent hot reducing gases from this generator are primarily intended for use in reducing metals from molten baths, the presence of this solid finely divided ash in the gases will be of no consequence. If, however,

it is desired to produce a clean gas, free from ash, the solid particles maybe removed by any conventional apparatus, such as scrubbers, electrostatic precipitators or the like.

The gas reducing compounds of the gas mixture reduce the zinc compounds in the molten bath to form metallic zinc which is vaporized.

The metallic zinc vapor is oxidized by means of air introduced above the bath through the air inlet tuyeres 45. The resulting fume containing zinc oxide issues from the converter through the opening atthe top and may be collected in any suitable manner.

After the operation of the gas generator has been'started, heating by means of pilot burners .is discontinued and the open ends of the ignition tube. are plugged.

When removal of zinc from a bath has been completed, the converter is tilted to dischargethe remaining material and another-charge is provided. During the charging and discharging operations the operation of the gas generator may be su'spended'by cutting oh the supply or air and oil. If the discharging and charging operations are conducted rapidly, the gas generator will be suiiiciently hot to resume operation without requiring reheating by means of pilot burners.

If desired the temperature'of the gas generator may be maintained by means of Ya pilot burner v through the observation tubes.

while the reducing operationsare suspended.

The progress of the heating of the interior of the combustion chamber may be determined operation of the gas generator, small amounts of a red heat.

the oil and air mixture may be introduced when the inner ends of the observation tubes are 'at When the observation tubes become bright red, heating by means ,of the pilot burner may be discontinued and the gas generator may thenbe operated at full capacity.v Since all of the air inlet nozzles communicate with the interior of the air chamber the supply of air to t the burners is uniform. The oil is regulated by means of an individual valve at each burner until the desired temperature in the combustion chamber is obtained. This; may be determined bymeans of a pyrometer inserted in one of the observation tubes or merely by the appearance of the inner ends of the'observation tubes which may be observed through the-outer open ends.

The oil and air mixture introduced is ignited instantly and because of the rapid whirling motion between two highly heated surfaces the oil 'mist is rapidly gasifled. 55

The provision of an air chamber surrounding the combustion chamber not only serves to per- ,mit preheating of the oxidizing gas but also perthe use of a relatively thin refractory lining for the combustion chamber because of the cooling effect of the gas passing through the air chamber.

Ga's generators constructed in accordance with the invention-have been successfully operated with a number of commercial fuel oilsincluding some of the relatively-heavy oils such, for example, as 18 Be. California fuel oil. Heavy oils require higher temperatures and greateramounts of air than the light oils, and the resulting gases are therefore relatively more dilute. The operating temperaturerange for heavy oils is about 750 C. to 900 0., and, for light oils, a.-

. temperature of about 650 C.:is used.

In using heavy oils, the addition of steam at the rate of about one gallon of water to ten gallons of oil is advantageous.

In starting the v.Gas generators constructed in accordance with the invention are of simple and sturw construction and easily operated and controlled.

. Few parts are required and the complete structure is relatively small and requires little space for. its installation. Operations may be quickly started or discontinued, andthe provision of a single air control valve permits easy control. of the operations. Owing to the fact that the oxidizing gas may be highly preheated, a high temperature flame of intense'reducing power may be obtained, V

-I claim: r

1. A gas generatorcomprisingan annular combustion chamber, an annular preheating cham-.

ber surrounding said combustion-chamber, one or more burners mounted on a wall of the combustion chamber within the walls of the preheat? ing chamber and providing means ofcommunicathe preheating chamber and the means for introducing tion between combustion chamber,

' combustible carbonaceous material into the comand combustible carbonaceous material into the combustion chamber adjacent the burners, means for introducing an oxidizing gas into the preheating chamber, and means for-conducting the gaseous productsoi combustion from the interior ofthe combustion chamber to a point of use. a v

3. A gas generator comprising three-cylindrical members so arranged as to provide an outer preheating chamber, an intermediate combustion chamber and an inner ignition tube, one or more .burners moimted on a wall of the combustion chamber within'the walls of the preheating chamber and. providing means of communication between the preheating chamber and the combustion chamber, means for introducing oil into the combustion chamber adjacent the burners, means for introducing an oxidizing gas into the preheating chamber, and means for conducting the gaseous products of combustion from the interior of the combustion chamber to a point of.

4. A gas generator comprising .three cylindrical members so arranged as to provide an outer preheating chamber, an intermediate combustion chamber and an inner ignition tube, one or more bin'ners moimte'd on a ,wall of the combustion chamber and providing means of communica-; tion between the preheating chamberv and the combustion chamber, means for introducing powdered coal into-theoombustion chamber ad.- iacent the burners, .means for introducing an oxidizing gas into the preheating chamber, and

means for conducting the gaseous products of chamber within the walls of the preheating combustion from the interior of the com bustion chamber to a point of use. nnnray mconoim-