US1875549A - Recirculation system - Google Patents

Description

Sept. 6, 1932. W, T BARKER 1,875,549

BECIRGULATION SYSTEM Filed March 27, 1929 2 sheets-sheet l Sept. 6, 1932.

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W. T. BARKER RECIRCULATION SYSTEM Filed-March 27, 1929 2 Sheets-Sheet 2.

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A TTORNE Y l .tl-11 Patented Sept. 6, 1932 Unirse STATES WARD T. BARKER, OF KANSAS CITY, IVIISSO'URIV i RECIRCULATION SYSTEM Aminata@ med March 27, 1929. serial No. 350,239.

The present invention'relates to recirculation apparatus for furnace constructions, and one prima-ry obj ect of the invention is to provide an improved mode of recirculation of the combustion or flue gases with a view to eliminating as far as possible the necessity for utilizing forced-draft operations for maintaining the recirculating function, and 'thereby avoiding the mechanical disadvantages attending the use of such force-draft equipment.

It is also sought to provide a recirculating system adapted for eiecting a better and more even or uniforln distribution ofthe heating action ofthe recirculated gaseous products, due to the more restricted character of the passages through whichthe gases are conducted through the system.

With these general objects in view, as well as various minor objects as will appear'in the course of the detailed description, the invention will now be described by referencel to the accompanying drawings illustrating one practical form of embodiment of fthe proposed improvements, after which those features and the combinationsv deemedto be novel will be particularly set forth and claimed. y

In the drawingsy Figure 1 is a horizontal sectional view illustrating a recirculating apparatusv constructed in accordance'with the present invention, and representinga section. taken on the line I-I of Figure 2;

Figure 2 is a vertical sectional view ofthe same, and represent-ing a section takenon the line II-II of Figure 1; and

Figure 3 is an enlargedsectional detail view, representing a section taken onl the line III-III of Figure 1.

Referring now Vto the said drawingsin detail, these illustrate the improved apparatus incorporated in a furnaceand still or vaporizer construction such as is adapted for refinery systems, and comprising front and rear walls 5, 6, respectively, connected by end walls 7 8, and a roof 9, all of appropriate masonry materials suitable for furnace operations. The space enclosed by these walls is sub-divided by a longitudinal vertical partition 10 to provide for a series of furnace or combustion chambers 12 between said partition and the front wall 5 and a corresponding series of vap'orizing or heat-transfer chambers 14 at the rear between said'partition 55 and the rear wall 6,-the chambers 12 being separated by transverse vertical partitions 16 and the chambers 14 being separated by similar partitions 18; each combustion chamber r12` furthermore communicates with the w vaporizing cham-ber 14 directly to the rear of it through an overhead space 20 left at the top of the partitionr 10 between the several transverse partitions 16'-18. Each, combustion chamber 12 is fired 'by its own 0| individual burner unit 22 v(oil or gas or other suitable type) admitted with its connections through a primary air opening 23 in the front wall 5. l i Mounted within the heat-transfer or va- 7 porizing chambers 14 are heating or Vaporizing units of any suitable or preferred type, as for example, banks of longitudinally extending tubes 25, either in separate lengths y corresponding to the length of each chamber, D or preferably continuous tubes each extending substantially the entirelength of the `furnace, thereby assuring ay uniformity of the vaporizing action upon the contents of the tube assembly by the practically even and 30 uniform` distribution of the heating effects throughout the same. y

Beneath thev vaporizing or heat-transfer chambers-14 is constructed a series of outlet .Y

passages, as by means of a tunnel structure 35 below the ground line or level corresponding to the Hoor 26 of the combustion chambers, and to this end the rear wall 6 and partition walls 18 are all extended below said level v to provide a separate gas outlet'passage 27 9u from each of the chambers 14. From each of these passages 27 a bypass or recirculating passage. leads through a tunnel or conduit 28 extending at an angle or diagonally between vertical side walls 29, topped by an 9 arch 30 (see Figure 3), to a discharge orifice y3 2 throughthe floor of the combustion chamber 12 corresponding to the nextvaporizing umt of the series. A vertical intermediate Wall 34 beneath the Hoor of each combustion 100 chamber is extended upward to provide baffle projection 34 to shield the corresponding orifice 32 somewhat from the primary combustion zone around the burner in. that chamber, as shown in Figure 2.

The series of combustion chambers and vaporizing units may be extended to any desired practical number, according tothe requirements of the installation, and the final vaporizing chamber 14 of the series communi- Cates With a liuc-gas tunnel or conduit l35 leading to the stack 40. y

In the flue gas aassage 38 is installed any suitable form of air prcheai'er construction 42', illustrated conventionally in Figure'l, for the preheating of air as supplied by a fan '43Ydriven by a motor 44, this primary air supply bengthus heated by the Waste flue gases andL conducted by a conduit 45 to each of the air openings 23 leading into the sevJ eral combustion chambers 12.

For theA supply of secondary air, as required, van Aair conduit may be provided in the end wall v7 for `an air inlet passage 46 beneath the ioor 26 of .the rst combustion chamber v12 and communicating With an intake orifice 47 in said chamber, as represented FigurelV of the drawings.

In the operation of the construction as above described, the products of the combus-I tion inthe first combustion chamber ofthe seriespass into the vaporizing chamber 14 by Way of the overhead passage20 communieating therewith and thence through the outlet space .27 and bypass conduit^28 and ori- .ice32into thenext combustion chamber 12 oftheseries. rHere the gases from .the first combustion chamber are combined with the products of combustion of the second combustion chamber v1.2 and With themrecirculated through the Corresponding vaporizing cham- .ber 14, Whereuponcthe rec rculating operation is repeated by the passage of the combined ,gaseous product 'through the second .set of passages 27,28, .to the orifice 32 ofthe third combustion chamber. .Thereafter the same operation is simply repeated for each vofthe :succeeding units ofthe series.

A recirculation process of the combustion .or heating gases .isthus vprovided in vvhich .a A.better andmore eiiic'ientdistribution ofthe hea-t to .the -vaporizino units is effected by virtue of the fact that the stream of the gaseous products is confined to a more limited space, resulting in a: more even and uniform distribution of the hot gases to the heat transfer surfaces of ther vaporizing apparatus. By recirculating the gases `over and over again through the successive combustion chambers and vaporizing chambers, theY temperatures therein are maintained at an efficient point with as little loss of heat as is practicable, and Without any undue dampening effect of the flue gases on the combustion Zones, since the recirculated gases are admitted at the opposite ends of the combustion chambers from the burners.

This recycling of the combustion gases repeatedly through a succession of the furnace units enables the recirculation principle to be carried out by means of the natural furnace draft, and eliminates the necessity of using a -forced draft for the operation of a plurality of such units. For example, if each of the units possessed a capacity of 15000 cu. ft., making a combined capacity of 60000 cu. ft. for four complete units illustrated, then the combined circulation Would comprise the 15000 cu. ft. originating in the iirst unit of the series, together With v45000 cu. ft. for the remaining units, of Which the greater portion would be represented by the recirculated gases entering them from the preceding units. By the elimination of the use of a fan mechanism for maintaining aforced recirculating draft, a serious mechanical difficulty is avoided, as the high temperatures encoungases tothe `orifice 47 provided in the floor of the firstV combustion chamber 12; although such supplementary .forced recirculation Will not ordinarily be necessary in a comparatively smallassembly of the type illustrated.

While `I have illustrated and described What t1 nowregard as a practicaland the preferred form of embodiment of my improvements, I desire to be understood as expressly reserving:the right to make all such changes ,or modifications as may fairly fall Within thescope of the Y'appended claim.

, What I claim is:

A recirculatingapparatus comprising, in

combination with a plurality of vseparate furnace units each havinga combustion chamber communicating with a vaporizing chamber,

means providing a conduit passage for conducting the heating gases from the Vaporizmg chamber of one of said umts to the combusti-on chamber of the next succeeding unit,

and a vaporizing assembly comprising a plurality of tubes each extending continuously through the vaporpizing chambers of all said furnace units.

: In wltness Whereofl hereunto affix my signature.

WARD T. BARKER.

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