US2512571A - Over fire air jet for stokers - Google Patents

Description

June 2 1950 w. M. $HWEICKART OVER FIRE AIR JET FOR STOKERS Filed July 31, 1944 Ill I I I /N[/EN7'UR wnu/m. m. SCHWEICKART TTU A/E/ Patented June 20, 1950 William'ltf'. Schweickart, Bay Village, dhio as- I signer to Iron' Fireman Manufacturing Company, Portland; Oreg.

* Thisinvehtion relates H pammanyw a means for supplying overfire new the combustion chamber in a furnace'. The main object of this invention is toprovide a means-ionsupplying over fireair in order to burn as much of the coke as possible from" the surface, leaving a lowertemperature within the fuel bed, and thus reducing the tendency to form lifikrs on thegrates; p I" A "*Th'sec'o'rfd object is to make it possible to lower the air velcity through the tuyeres, thus-reducing the amount of fly ash produced.

The third object is to reduce the amount of smoke formed by forcing suflicient preheated air to impinge upon the forming coke as it emerges from the retort.

The fourth object is to provide an over-fire air jet which can be substituted for one of the regular tuyere sections and in which it is possible to use as many of the jets as desired and dispose them around the periphery of the retort to suit any specific requirement.

The fifth object is to so construct the jet that the riser portion thereof may be disposed at any desired radius from the retort center and that the horizontal connection between the tuyere section and the riser is protected by refractory material and ashes and whatever heat is transmitted thereto is absorbed by the air delivered to the jet and finally reaches the combustion.

I accomplish these and other objects in a manner set forth in the following specification as illustrated in the accompanying drawing, in which Fig. 1 is a fragmentary plan showing a retort and a plurality of air jets in conjunction therewith.

Fig. 2 is a fragmentary section taken along the line 2-2 in Fig. 1.

Fig. 3 is a fragmentary end elevation taken along the line 33 in Fig. 2.

Fig. 4 is a transverse section taken along the line 4-4 in Fig. 2.

Fig. 5 is a transverse section taken along the line 5-5 in Fig. 2.

Similar numerals refer to similar parts throughout the several views.

Referring in detail to the drawing, there is shown the upper end ll] of a retort, above which is disposed a locking ring II for the tuyere elements l2 which are made separate for manufacturing reasons, and for expansion purposes. The tuyeres l2 have the usual inturned air ports l3 which ports are downwardly inclined, and are held in position by means of the ring H, which gen'el' allyto stol'iers and V v "litp icatit'iriiuly 31, 1944; serial No. 547,490

" 1 Claim. (01.1'10'475) e ages the notch:- l 4' formed in "each element'i I 2.

Such tuyere elements are now incommorr us'e, and supply air from the plenumchamber 15' to the tuyere elements l2; from whence E it escapes 'through: the parts It toward the center "of the firebed. a

Referring particularly to" myinventiomlsa m'e will-be seen to consistiof' a modi'fied form of tuyre section H5 which differs from the elements'fl in that it has an outwardly tu-rned fiar'igei [1, from which radiates the horizontal connecting pipe l 8, which extends into the flange 19 formed on the lower elbow 20 of the vertical riser 2|, preferably of somewhat flattened cross section as shown in Fig. 4. At the upper end of the riser 2| is formed the elbow 22, having the inturned and somewhat depressed tip 23. The tip 23 is preferably round as shown in Fig. 3, although it may assume any other desired shape. It is desirable to cover the horizontal pipe l8 with a, refractory material 24, to protect same. It is desirable to unite the parts 11 and 18 to clamp them in their proper relationship.

In some instances it may be found desirable to draw the air supply for the riser 2| directly from the plenum chamber or from the fan itself, although the first described form of the device possesses the highly desirable quality of being insertable into any sectional tuyere and selectively positioned about the periphery thereof, and moreover, is easily replaced or changed should such action be found desirable.

It can be seen from the foregoing that any coke which forms in the fuel bed is burned as:

completely as possible from the surface by means of the air jets 25 coming from the tips 23, thereby maintaining a lower temperature within the fuel bed and holding the ashes below the fusing point, and thereby reducing the tendency to form clinkers on the grates. It will also be seen that the presence of the over-fire jets 25 makes it possible to maintain a lower air velocity at the tuyre ports l3, thereby reducing the fly ash, which is highly desirable.

It will also be seen that by forcing preheated air against the forming coke column, the combustion is improved and the amount of smoke formed is greatly reduced.

In practice, it is found that the quantity of air passing from the tips 23 is normally held at approximately 40% to 50% of the total air supply. The velocity of the air leaving the tips 23 should be between 2,000 and 3,000 feet per minute.

The apparatus above illustrated and described would be the type employed in clinker type equip- 3 ment, whereas when used in connection with ash removal equipment, the passageway for the overfire air will be led upward at an angle from the top of the tuyere blocks until a, diameter equal to that of the grate is reached. At that point it will pass vertically to the desired height where it is turned downward for impingement against the coke column."

I am aware that numerous attempts have been made to supply over-fire air to stokers. I therefore do not intend to cover such devices broadly but I do intend to cover all such-forms and modifications thereof as fall fairly within the appended claim. 4

I claim:

In an underfeed stoker, the combination of a retort having means for feeding, coal thereto, means defining a. plenum chamber surrounding said retort, tuyre blocks disposed around said retort, having downwardly and inwardly directed air passages therethrough which passages at their outer end communicate with the plenum vchamber and at their inner ends with the interior of the retort, a horizontal pipe communicating with said horizontal pipe having a downwardly inclined tip at its upper end, pointed to- .ward the vertical axis of said retort and adapted 4 to discharge air toward a central coke column. above the top of the uppermost tuyre portion for the purpose of breaking up any coke column which may be formed therein, said riser pipe extending upwardly above the uppermost portion of the tuyre blocks.

' WILLIAM M. SCHWEICKART.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 285,397 Dodge Sept. 25, 1883 558,894 Boynton Apr. 21, 1896 624,009 Glessner May 2, 1899 839,003 Kline Dec. 18, 1906 852,209 Watson Apr. 30, 1907 860,504 Treibel July,16, 870,686 Reid Nov. 12, 1907 1,066,042 Parsons- July 1, 1913 1,138,060 Gaines May 4, 1915 1,229,387 Willett June 12, 1917 1,387,453 Cole Aug. 16, 1921 1,468,536 Lawter Sept. 18,1923 1,603,601 Hejma Oct. 19, 1926 1,607,312 Schierenbeck Nov. 16, 1926 2,068,018 Goetz Jan. 19, 1937 2.362.127

Gehl Nov.- 7. 1944

Images