US2920715A - Gas handling system - Google Patents

Description

Jan. 12, 1960 R. G. sTREUBER GAS HANDLING SYSTEM Filed oct. 29, 1954 2 Sheets-Sheet 2 IN VENTOR RUDOLF G, STREUBER BY 2M? 5M ATTORNEY r ,x 2,920,715 Patented Jan. Y12, 1960 GAS HANDLING SYSTEM Rudolf G. Streuber, Somerville, NJ., assignor to Research gorporation, New York, N.Y., a corporation of New ork Application October 29, 1954, Serial No. 465,533

' 2 Claims. (Cl. 18S-1) The present invention relates to gas handling methods and apparatus and more particularly and specifically to flue gas distributing and mixing constructions.

y)It is desirable in present day industrial installations employing a bank or banks of furnaces to utilize gas precipitators so that a single precipitator installation will service ilue gases from a plurality of furnaces in the bank. By such an arrangement a duplication of costly precipitator constructions and installations for each individual furnace is avoided, thereby permitting lower cost and more economical installations and operations.

However where flue gases to be treated by a single precipitator are obtained from a plurality of individual sources or furnaces the gas volumes, temperatures, moisture contents, dust or fume concentrations and pressures will vary from each individual source thereby making it extremely difficult to provide precipitator operating conditions that will result in optimum performance unless special arrangements are made to provide substantially continuous uniformity in those aforedescribed characteristics of the flue gases passing through the precipitator.

Heretofore special mixing devices or chambers have been utilized to intermix ue gases from a plurality of individual sources before introducing the gasses to a precipitator. These mixing devices have included bulky, ex pensiveV equipment consisting of extensive ducts and bafing through which the combined ilue gases from plural sources pass prior to entering the precipitator.

In these prior constructions it has been necessary that the gases from each of the separate sources pass through ducts of approximately half the cross-sectional area of its normal flue size, be carried through an extensive series of baffles involving numerous right angular turns and then enter the precipitator. It is inherent in these prior constructions that there be a substantial pressure loss by reason of the restricted ue sizes and the numerous right angular turns in the ducts. This pressure loss results in need for oversize and costly fans and auxiliary equipment for carrying the gases through the precipitator and its auxiliary apparatus, and at the same time results in a high rate of drop out of suspended material at points of right angular directional change and through the extensive series of baffles. Because of high drop out additional provision must be made for hopper constructions for the purpose of collecting and removing drop out materials.

Accordingly it has been discovered that prior devices of the type heretofore described result in extremely costly and space consuming installations which are inefficient in operation and fail to permit the operation of precipita- -tors at optimum performance.

Therefore, it is a general object of the present invention to provide flue gas distributing and mixing constructions which substantially eliminate the inherent disadvantages in prior constructions and which provide for new` and useful results in ilue gas precipitation.

A primary object of the present invention is to provide flue gas distributing and mixing constructions which will permit the maintenance of precipitators and their auxiliary apparatus at uniform and optimum operating conditions, regardless of variations in gas characteristics from individual sources being combined and introduced into the precipitator.

Another object of the present invention is to provide for flue gas distributing and mixing constructions in which pressure losses through the duct systems between the plural sources of gas and the precipitator are substantially reduced thereby resulting in greately reduced size requirements for auxiliary appurtenances to the system such as fans and the like, and to provide apparatus in which the cross-sectional areas of the required ducts are greatly reduced.

A further object is to provide apparatus of the type described in which all right angle turns in the gas passages are eliminated thereby reducing not only the pressure losses in the system but also the amount of drop out of suspended material throughout Ithe length of the system. i

Still another object is to provide flue gas distributing and mixing constructions for use with a plurality of flue gas sources in which a two-pass, two-directional duct system is provided wherein there is restricted communication between the first and second passes resulting in a proportional intermixing of the gases between the rst and second passes, reducing the total volume of gas passing through the entire length of the system, reducing pressure loss through the length of the system, and providing for increased intermixing of the gases.

lt is still a further object and advantage of the present invention to provide gas mixing and distributing apparatus which will enable the installation of such apparatus at greatly reduced costs over prior installations by reason of a reduced requirement in space and size of the entire installation, yet apparatus which will provide for greatly increased emciencies in the performance of the precipitators and auxiliary equipment.

Still other objects and advantages of the instant invention will become readily apparent to those skilled in the art when the following description and general statement is read in the light of the accompanying drawings.

The nature of the present invention may 'be stated in general terms as consisting of gas distributing and mixing apparatus for utilization with a plurality of gas sources including an elongated duct, a partition dividing said duct into two passes, one pass of said duct having communication with a plurality of spaced flue gas sources, a bleeder slot in said partition providing for limited communication between said passes, and a mixing chamber intermediate the length of said duct providing for directional change in gas ilow between the tWo passes of said duct, and communication being provided between the second pass of said duct and gas cleaning apparatus.

Referring now to the accompanying drawings in which like numerals designate similar parts throughout the several views:

Fig. l is a schematic View of the gas distributing and mixing apparatus constituting the present invention.

Fig. 2 is an enlarged horizontal section through a fragmentary portion of the system including the gas mixing chamber.

Fig. 3 is a vertical section taken on line 3-3, Fig. 2.

Fig. 4 is a vertical section taken on line 4-4, Fig. 3.

Fig. 5 is a vertical section taken on line 5-'5, Fig. 3.

Referring now to Fig. l of the drawings in which the basic concepts of the present invention are diagrammatically illustrated, l() generally designates an elongated duct having communication at spaced points along its length with the exhaust ducts, generally designated at 12, from a plurality of individual furnace sources or the like, and a plurality of gas cleaning devices such as electrostatic precipitators 14 having communication with the duct il) at spaced points along its length and in spaced relationship to the furnace ducts l2.

The flue gas duct 1G, which may be of any desirable cross-sectional coniiguration, is divided preferably centrally by a partition i6 which extends throughout the length of the duct and separates it into two substantially equal passes. Located at substantially the longitudinal center of the duct it) is a mixing chamber which provides intercommunication between the two passes defined by the partition lo.

With particular reference to Fig. 4 it is seen that partition 16 consists of a pair of plates which converge downwardly and inwardly within the duct to terminate at their inner ends in spaced relationship to define an opening or bleeder slot Ztl between their inner ends.

With particular reference to Figs. 2, 3, and 5 it can be seen that the partition ll is interrupted at substantially the longitudinal center of the flue itl and the mixing chamber 1S is located intermediate the separated ends of the partition 16. The mixing chamber i3 contains a fluted mixing apparatus generally designated at 22 and consisting of a plurality of fan-shaped convolutions or corrugations 24 which are positioned with their apex portions on the lower wall of the flue it) to extend upwardly therefrom with the primary lengths of the corrugations 24 extending longitudinally of the flue l0. It will be noted, with particular reference to Fig. 2, that the mixing apparatus 22 in its fan-shaped configuration is composed of a plurality of alternately arranged convolutions each of which originates at a base portion adjacent th'e bottom wall of the iiue it) to extend upwardly and outwardly at substantially 45 degree angles from the vertical whereby the alternate corrugations throughout the entire width of the flue are disposed in opposite directions longitudinally of the flue providing alternately opposite gas passages extending upwardly and outwardly from the base portion.

While the mixing apparatus 22 extends throughout the entire width of the flue 10, the upper extremities of the alternately opposite corrugations 24 terminate at a spaced distance below the top wall of the liue itl to provide a substantially open area thereabove in the mixing chamber where turbulence created by the ilue gas directional change, to be hereinafter described, occurs and causes substantial intermixing of the ilue gases in this region where they are no longer separated by partition 16.

In the foregoing construction it is to be understood that the furnace exhaust ues 12 in each instance cornmunicate with the flue 10 in the region of what is termed the first pass below the partition i6, while the precipitators 14 communicate with the second pass above the partition Operation In operation of the present apparatus flue gas exhausting into the duct lil enters below the partition i6 and moves therethrough in the direction of the mixing chamber 18. This provides for flue gas moving through the duct in opposed directions on either side of the mixing apparatus 22 in the duct lt) below the partition Siti. When these gases moving in the first pass of the duct i9 enter the mixing chamber the corrugations 2li of the mixing apparatus 22 will direct the gases enteing from opposite sides of the chamber upwardly through a 45 degree angle and thence into the upper or second pass of the duct itl above partition 16 on the opposite side of the mixing chamber whereupon the gases will flow from the centrally located mixing chamber outwardly lengthwise of the duct 10 in the direction of the precipitator intakes. By reason of the foregoing there is created in each longitudinal half of the duct lil, as divided by the mixing chamber 18, ue gas flow above and below the partition t6 which is moving in opposite directions on either side of the partition. By reason of the bleeder slot 20 throughout the length of the partition 16 there will be a continuous intermingling and mixing of the oppositely or counterflowing gases on either side of the partition in a proportion. controlled selectively by the -size of the bleeder slot Zt). In addition, the inclined surfaces of the two plates constituting the partition i6 will prevent the collection and deposit of any drop out materials in the upper or second pass of the duet since such materials will tend to slide into the bleeder slot 20 where the intermingling turbulence of the two oppositely flowing gases will mix them sulciently to again place them in suspension in the ue gas.

The particular construction of the mixing apparatus 22, while providing for a change in direction of ow of the gas, eliminates any right angular change of gas flow direction and thus eliminates the high rate of drop out which has heretofore been common at such points of gas tiow direction change. At the same time the mixing apparatus provides for a continuous, unrestricted flow of the gases without substantial pressure drop.

As heretofore set forth, the intermixing and intermingling of the flue gases owing above and below the partition i6 through the medium of the bleeder slot 20 will substantially reduce the total volume of gas passing through the mixing apparatus thereby reducing the size requirements of the duct itl and reducing the tendencies toward pressure loss in the liue system.

it has been discovered that mixing and distributing apparatus constructed substantially in accordance with the foregoing description will provide highly eflicient mixing of the ue gases from a plurality of individual sources resulting in gas entering the precipitators having uniform, characteristics thereby enabling the operation of the precipitators at constant, optimum performance.

From the foregoing it is readily evident that apparatus and methods of handling Hue gas distribution and mixing are provided which satisfy and achieve all of those objects and advantages heretofore set forth.

Having thus described my invention, its novel construction and operation, and the new and useful results obtained thereby, what I desire to claim is:

l. Gas distributing and mixing apparatus for utilization with a plurality of gas sources and `gas cleaning apparatus including an elongated duct, a mixing chamber located substantially centrally of the length of said duct dividing the duct into two end sections, each end section of said duct being divided longitudinally by a partition into two gas passes, one gas pass in each of said two end sections having communication with plural spaced gas sources, the second gas pass in each section having communication with gas cleaning apparatus, and fluted mixing means in said mixing chamber directing the gas flow from the first-named gas pass in each end section to the second-named gas pass in the other end section thereby providing counterow of gas in the two passes of each end section wherein said partition dividing adjacent gas passes in each end section of said duct consists of a pair of plate members inclining downwardly and inwardly from the sides of said duct and having their inner ends terminate in spaced relationship substantially centrally of said duct providing a bleeder slot between the adjacent counterliowing gas passes permitting limited t interrnixing of counteriiowing gases therein.

2. Gas distributing and mixing apparatus for utilization with a plurality of gas sources and gas cleaning apparatus including an elongated duct, a mixing chamber located substantially centrally of the length of said duct dividing the duct into two end sections, each end section of said duct being divided longitudinally by a partition into two gas passes, one gas pass in each of said two end sections having communication with plural spaced gas sources, the second gas pass in each section having communication with gas cleaning apparatus, and iluted mixing means in said mixing chamber directing the gas ow from the first-named gas pass in each end section to the second-named gas pass in the other end section thereby providing counterow of gas in the two passes of each end section wherein said uted mixing means in said mixing chamber consists of a plurality of iluted corrugations of generally fan-shaped construction located in said chamber, said fluted corrugations transversely of said chamber extending in alternately opposite directions longitudinally of said chamber, and said uted corrugations being inclined upwardly and outwardly of said chamber in angular disposition in substantial alignment between the opposite passes of each of the two end sections ofthe duct.

References Cited in the file of this patent UNITED STATES PATENTS 499,799 Parkinson June 20, 1893 512,681 Clute Ian. 16, 1894 514,439 Blessing Feb. 13, 1894 2,246,994 Herbster June 24, 1941 10 2,659,449 Kaiser et a1. Nov. 17, 1953 2,662,610 Heinrich Dec. 15, 1953 2,682,313 White June 29, 1954

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