US1591090A - Reversal and control of regenerative furnaces - Google Patents

Description

Patentedl July 6, 1926.A

UNITED* STATES PATENT OFFICE.l

GEORGE n. ISLEY, OE WORCESTER, MASSACHUSETTS, ASSIGNOR To MORGAN CON-l STRUOTION4 COMPANY,v OE WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

Y REvERSAL AND CONTROL OE REGENERATIVE EURNACES.

* Application mea February 151923. serial Nc. 619,185.

The presentvinvention relates to the reversal aA- d control of regenerative furnaces, particul rly those using hot producer gas for fuel. The invention utilizes, in part, the

principles of operation which characterize the apparatus shown and described 1n my United States Letters Patent No. 1,464,002, dated August 7, 1923, all as more fully hereI inafter described with reference to the accompanying drawings, wherein- Fig. 1 is a diagrammaticjplan view of the invention as applied to a regenerative l furnace using producer gas as fuel. y

Fig. 2 isa sectional view showing one of the air regenerators of the furnace with its associated parts.

vices associated with each air -regenerator of the furnace, and also with a waste-heat boiler. l

Like reference characters referto like parts in the different figures.

Referringto Fig. 1, the heating chamber `1 of the furnace is in communicatlon,` at opposite ends, with air lregenerators 2, 2 and gas regenerators 3,' 3', the last named being connectedl by means of flues 4 and 4', respectively, with a gasy reversing valve 5 of any well known, type,here shown, by way of example, as of. the rotary. or Oscillatory type. Said valve in the position illustrated is adapted to direct hot producer gas, from a Supply conduit 6, into the pasf Sage 4 and thence to the furnacerby way of regenerator 3; at the same time, serving to connect the exhaust side of the furnace, by way of gas regenerator 3 and passage 4 with a wasteheat boiler 7. When the valve 5 is reversed, the flow of fresh hot. gas tothe furnace is by way of passage 4 and regenerator 3, whlle the products of combustion at the same time pass through regenerl ator 3 and passage 4 tothe waste heat boil- The air regenerators 2, 2' provide, adjacent the furnace, the usual brick checker work8, and preferably,` in addition theretoi Said `regenerators have extensions 9, 9

providing metallic checker work 10, as

Fig. 3 is a sectional 'view` of drafting deshown in Fig. 2.' Each extension9, 9, and

also the exit passage 11 from wasteheatl boiler- 7 communicates with an open-ended d'uct 12, having a suitable contracted throat portion 13 wherein is disposed a fan or blower of the type, for instance, shown at 14 in' Fig. 3. Each of the three fans. or blowers 14 is driven independently by means of a reversible, independently controlled, actuating device, as, forinstance, a steam turbine 15, or a reversible electric mOtor,-such as shown i-n the aforesaid copending applithrough a suitable Opening provided bythe enlargement 19 which connects each passage 9, 9 and 11 with its associated duct 12; in thisway, the removal of any one or all of these blowing devices, for purposes of repair or replacement, is greatly facilitated, lwith a minimum loss lof time occasioned by the necessity for such replacement. In fact, either of the two blowing devices associated with the air regenerators may be removed and replaced, or repaired, without shutting down the furnace, when vsuch removal takes place during the intake phase of the blowers operation. As also Shown 'in Fig. 3, the bearings 17 for each fan or blower, bein-g exteriorly located, are not subject to overheating; furthermore, if desired, said bearings may be additionally cooled by the use' of, afan 20 carried by shaft 16 On the Outside. .v

vIn connection with the passage of gases through the furnace from right to left, as shown by the arrows in Fig. 1, the turbine 15, associated with regenerator passage 9', causes its fan or blower 14 to draw in the air through the Openupper end of associated duct 12, while the, other air regenerator turbine? associated with passage 9, .runs in the opposite direction, to cause its fan or blower 14 to draw waste gases from the furnace for expulsion from the upper end of left hand duct 12. The reversal of the furnace is effected by simply reversing both the right and the left hand turbines 15, l5, and also the valve 5, it being understood that with either direction of flow through the, furnace, the third or intermediate duct 12, as-l sociated with waste heat boiler 7, is 'invariably employed for outflow or exhaust. However, the turbine driven fan associated .with this third or intermediate duct A12'is is relied upon to produce stack draft'. Gon-- sequently, in the air regenerators of the'system, the usual brick checker work 8 is supplemented by the metallic checker work l0, in order to absorb from the outgoing. gases as much as possible of the heatl that in ordinary systems i's'purposely retained for the production'of stack draft. In this connection, theuse of metal checker Work in these secondary regenerators 9 and 9 is preferable to brick, since metal has a natural tendency to readily'pick up and give olf heat at comparatively low temperatures.

In' the gas regenerator passages however, this secondary regeneration is not availed of, since the producer'gas from conduit 6 greater volume of gases than the blower on the ingoing side, due to the increase of Volume under high temperature; this is made possible by the independent control of said fans or blowers, which permits one to be operated at a higher speed than the other. Again, the atmospheric conditions may at times-be such as to require very little mechanical assistance in drafting the furnace; at such times, either one or both of the fans or blowers may be slowed down, or may be rendered inoperative.

'-To cool the furnace proper for purposes of repairyall three fans. or blowers 14, 14, 14"are operated in thedischarge direction,

to draw out all gaseous products throughthe may be generated, and the proper temperais alreadyv at a temperature of .approxi-v mately 120010 Fahrenheit, and consequently, the usual regen- craters 3 and 3 are suflicient. Instead, the low temperature heat contained in the waste products leaving by way 'of valve 5 is utilized in the boiler 7 for the generation of steamA with which to drive the threeturbines 15, 15, 15.\

It is to'be noted that the-apparati1s affords positive control over vboth theV ingoing and outgoing gases,- owing to the fact that the mechanical drafting devices used for both ingoingand outgoing gases arev t-ures' maintained in the gas regenerators 3, 3. Itwill be-noted further, -in connection with the use ofthis waste heat boiler, that the fresh. gas and air suppliedto the furnace are kept entirely separate, one from the other, at all times and in all placesexcept where they are united in the furnace.` Therefore, all danger of explosion by contact of rfresh gas and air in the waste heat boiler is avoided, which is not .the case wherewaste heat boilers are used under existing conditions. That is to say, with the ordinary use of Waste heat boilers and also with the ordi-k nary disposal of all combustion products through a single stack, eachreversal of a regenerative furnace creates the possibility of an explosion, because there' is invariably the merging into a single current, of the fresh gas and the fresh air which is trapped each time in 'the respective gas and air regenerator passages. In the present construction however,vv the trapped fresh gas is exhausted independentlyof and apart from the susceptible of any manipulation or varia-A ,tion that may be desired. In other Words,

the separate and independent control and operation of the turbines or motors of the three fans or blowers 14, 14, 14 gives to the apparatus, wholly apart from the use of any 'dampers or valves, the widest `possible ylatitude and flexibility in. meeting all of thev various conditions of furnace operation. For instance, under normal conditions of operation, the fan or blower on the outgoing,` side of the furnace must be able to handle a trapped fresh air, and consequently no explosive or combustible mixture vis ever formed outside of the furnace.

l I claim,

l 1. Reversing apparatus for a gas-fired regenerative furnace,'comprising a Valve associated with the gas regenerator passages of the furnace, for reversing the gas supply, inl combination with independently reversible blowing devices associated, respectively, with each of the air regenerator passages of said furnace.v

2. Reversing apparatus for a gas `fired rei generative furnace, comprising a valve associated with the gas regenerator passages of the furnace, for reversing the gas supply, in

combination with independently 'reversible' blowing devices associated, respectively, with each of the air regenerator passages of said furnace, and a third independent blowing device'assoc-iated with said gas reversing valve. to exhaust the products of combustion delivered therethrough. v

3. Reversing apparatus foi a gas fired regenerative furnace, comprising`a valve assogenerative furnace, comprising a-valveassociated with the gas regenerator passages of the furnace, for reversing the gas supply, in combination with independently reversible blowing devices associated, respectively, with each of the air regenerator passages of said furnace, the latter'comprising primary and secondary checker work'chambers.

i reversible 5. The combination with a gas fired regenerative furnace, of a waste heat boiler to receive the products of combustion issuing selectively from each of the gas regenerator passagesof said furnace, and means independent ofsaid waste heat boiler, and isolatedtherefrom, for supplying air to said furnace.

6. The herein described vmethod of utilizing a portion of the exhaust gases of a regenerative furnace in a waste heat boiler, which consists in segregating for use in said boiler the gases discharged through the gas regenerator passages of'said furnace, and' maintaining the supply of air to saidfurnace tlnpugh passages isolated from said waste heat boilerL.'

7. In a-gas .firedh regenerative furnace, a

reversible blowing device associated with each air regenerator'passage, in combination with' a third blowing device common to both gas regenerator passages.

8. In a gas firedv regenerative. furnace, a

'reversible blowing device v'associated with each air regenerator passage, in combination with a third blowing device common to both gas regenerator passages',L and mea-ns selectively operable on said". first me'iitioned blowing devices for causing them either to exhaust gases from both ends ofthe'furnace simultaneously, or to supply air to lboth of said -endssimultaneously 9. In a vas fired regenerative furnace, .a lblowing device associatedA with eachmair regenerator passage, in combination with' a third blowing device comisin to both gas regenerator passages, and `inea-ns selectively operable on saidffirst mentioned blowing 'devices for causing` themy either to exhaust gases .from bothends of the furnace simultaneously, or to supply air to one end while exhausting gases froml the other end. 10. In a gas vfired regenerative furnace, a reversible blowingdevice associated with each air regenerator passage, in combination with athird blowing device common to both gasreg'enerator passages, and means selectively operable on said first mentioned blowing devices for causing them to supply air to .both ends of the furnace simultaneously, or to supply air to one end while exhausting gases from the other end.

. 11. In apparatus of tue class described, the

lcombination-with a conduit adapted forv the flow of-hot gases, of a fan disposed therein to procure movement of gases -through said conduit, said fan and its bearings being c arried by a member insertible insaid conduit as a unit from the outside, to permit theremoval and replacement of said fan .without dismantling the conduit. v

l2. The combination with a gas fired regenerative furnace, of a wasteheat boiler adapted to be heated byl combustion prody ucts issuing from said furnace, means for connecting said waste heat boiler, alternately, at each lreversal of the furnace, with one or the other of the gas regenerator passages y o'f said furnace, and drafting means isolated from said waste heat boiler for withdrawing combustion products alternately from one or the other of the air regenerator passages of the furnace, thereby topre'vent admixture, in said waste heat boiler, yofy freshair land fresh gas trapped in the ,fiespective air and gas passages when the fur nace is reversed.

13. The combination with a generative furnace, of drafting meansfor the disposal :of combustion products ein? h'austed alternately at veach. reversal ofglthe furnace from one or the 'other of the as .re

generator passages ofsavid furnace, an 'other ica drafting means, independent `ofy said rst l mentioned drafting means for withdrawing combustion products alternately from one or the. other of the air regenerator'passages of the furnace, thereby to preventA 'ad-mixture, in a single drafting means, of fresh gas and fresh air trappedin .the respective air vand gas passages when the vfurnace is reversed.

14. The combination with a gas fired regenerative furnace, of a waste heatboiler adapted to be heated by-combustion products issuing from said furnace, means for .connecting said wasteheat boiler, alter `liately, at each reversal of the furnace, with one-or the other of the gas regenerator passages of said furnace, and draftin means isolated `from said waste heat boiler for withdrawing combustion products alternateiso . `5 spective air and 'gas passages when the fur- "passagerscomprising a primary refractory 1y from one or the other of the air regeneracheckerwork chamber and @communicating tor passages of the furnace, thereby to presecondary metallic checkerwork chamber, the vent admixture, in` said Waste heatboiler, of latterfor extracting heat from said combus# 10 "fresh air vand fresh gas trapped in the re tion products at approXimately the temperatures utilized in said Waste heat boiler.

4Dated this ninth'day Of February, 1923. p GEORGE ISLEY.

nace is reversed, each of said air regenerator

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