US2108871A - Checkerwork - Google Patents

Description

Feb. 22, 1938. H, l SMALLEY 2,108,871

CHECKERWORK Filed May 26, 1937 2 Sheets-Sheet 2 INVENT OR. MEN/ay /VALLEY ATTORNEYS.

. Patented Feb. 22,

UNITED STATES PATENT OFFICE 2.108.871 crmcxsawonx Application May as, 1937, serial No. 144,907

9 Claims.

'This invention relates to regenerative furnaces and, more particularly, to a regenerative checkerwork for such furnaces.

Many elements enter into .the ability of a re- The invention will be described with particular reference to the drawings, in which Fig. 1 is aperspective view of a checker-work constructed in accordance with its preferred embodiment;

generative checker-work to function efficiently. Fig. 2 a sectional view taken on line II-II of Fig. 5

For one thing, the weight per cubic foot of the vregenerative checker-work should be as high as possible to provide the maximum heat storage capacity for the regenerator. Also, the checkerl0 Work should be constructed to produce a maximum area of heat transfer surface and a large volume of brickper cubic foot of checker chamber. Another, and very important, factor is the ability of the regenerative checker-work to disover its surfaces. This last-mentioned factor, in reality, controls the others for the air must be distributed before full advantage can be taken of the other factors.

However, an undesirable feature of many regenerative checker-works available heretofore is that dust from the furnace gases deposits on the surfaces of the bricks forming the checker-work. This accumulation of dust not only retards the flow of gases through the regenerative checkerwork but also retards heat exchange between it and the gases passing therethrough. oftentimes, severe fouling of the checker-work, rather than the condition of the furnace brick-work, brings the furnace campaign to a close. Obviously, it is highly desirable to maintain the surfaces of the checker-work as free as possible from these dust deposits. Heretofore, the removal of the dust deposits has been diiiicult, and often it has en- A tailed rebuilding the structure with replacement of damaged brick, or special constructions open to various disadvantages have been necessary.

An object of this invention is to provide a regenerative checker-work which minimizes dust accumulation and which can readily be freed from dust deposits.

Another object of this invention is to provide a regenerative checker-work which is constructed to distribute gases flowing therethrough over the surfaces thereof for optimum heat exchange.

Another object of this invention is to provide high weight of checker brick per cubic foot of regenerative checker-work volume.

A further object is to provide a regenerative once installed. is of a solid, durable construction, Still another object is to provide a regenerative checker-work which is constructed largely from bricks of ordinary rectangular form, i. e.,

straights,`and which is easily constructed.

tribute the air and gases passing through it and checker-work which is easily installed and which,

l; Fig. 3 a sectional view taken on line III- III of Fig. 2; Fig. 4 a perspective view of a straight; Figs. 5 and 6 perspective views taken from the top and bottom, respectively, of the stretchers used in constructing the checker-work shown in Figs. 1 to 3; Fig. 7 an end elevation of a modified form of stretcher: Fig. 8 a perspective view of a righthand stretcher; and Fig. 9 a perspective view of a left-hand stretcher.

The checker-Work shown in the drawings is constructed from brick shapes I (Fig. 4) and 2 (Figs. 5 and 6). It is constructed largely from ordinary straights I that are disposed on edge in courses l. The courses 4 comprise a plurality of longitudinally aligned and abutted straights I forming parallel rows 6 spaced to receive similar straights extending between the rows 6 and aligned in rows 6a normal to the rows 6. In each course rows 6 and 6a thus cooperate to form separate flue openings, as seen in the drawings.

'I'he courses 4 are separated by intermediate courses 5 built from aligned and abutted special shapes, or stretchers, 2 (Figs. 5 and 6) which mount the straights I. To this end they are provided -on one face with a longitudinal groove 'I adapted to receive the edge of bricks I. This is traversed midway of the brick length by a similar but transverse groove 8. The opposite face is recessed at each end to provide portions 9, Fig. 5, of such length that when two of the stretchers are abutted there is formed a groove which receives the edge, or side, of straights I with Ia slightclearance.v The recesses 9 are connected bya longitudinal groove IIl similar in width to the groove 1. As shown in Figs. 1 to 3, the stretchers 2 form a plurality of rows, or intermediate courses, 5 which are parallel to and disposed between the rows 6. Preferably the stretchers are mounted, as seen best in Fig. 1, with the grooves 1 pointed downward and thus engaging a lower row.6, while grooves I0 are turned upward to receive the edges of the straights in the overlying row 6. The rows of stretchers thus combine with the rows 6 to form a plurality of walls I2 that extend from the top to the bottom and from end to end of the checker-work so that each adjacent pair of walls forms a separate flue through the checker-work. The transverse grooves 8 and the' recesses 9 are aligned transversely of the checker-work 2 and receive the edges of the straights forming the rows 6a. From Fig. 1 it will be seen that the straights I forming the rows 0a extend between adjacent pairs of the walls I2 transversely of the flue formed thereby. As the recessed portions 0 are at the ends of the stretchers` 2, and the transverse grooves l are at the center of the opposite sides thereof. the straights which are positioned thereby are staggered. as best shown in Fig. 2. By thus staggering the straights forming the rows 0a, the gases passing through the fiues formed by walls I2 are forced to follow a tortuous path so that they must contact the surfaces of the cross rows 8a, thus affording maximum heat exchanging contact.

The spacing of the cross checkers is governed, of course. by the length of the stretchers 2, so the flue size can be varied by the use of stretchers of appropriate length. Thus, using 9 x 41/2 x 3- inch straights and stretchers -of the same dimensions, the cross straights will be on 9inch centers. providing a flue opening six inches square. If a larger opening is needed, the stretchers can be made longer, say ten inches, which wolild give an opening 6 x7 inches. And the 'stretchers can be made to takeI other sizes of straights, or to vary the distance of the straights, according to need.

'Ihe stretchers 2 are provided on one side with noses I4 that protrude into the fiues of the checker work and which produce turbulence in the gases flowing through the checker-work. In the construction shown, noses Il project in opposite directions from adiacent courses of the stretchers 2, as seen particularly in Fig. 3. The noses may of course be disposed in arrangements other than shown in the drawings. With ordinary 9- inch straights the stretchers shown suffice for building the particular structure shown. With larger sizes of brick, or for other nose dispositions. it may be necessary to use rightand lefthand stretchers. as those skilled in the art will understand. Thus in Fig. 8 the nose portion Ilb is to the right of the recessed end portion 9b. while in the left-hand stretcher shown in Fig. 9 the nose portion Ilc is to left of the end portion 8c when looking axially along the stretchers when they have recessed end portions at the top of the closer end thereof. It will be' seen that the stretcher courses are formed by alternately positioned lefts and rights which are placed with the recessed portions 8b and Bc abutting whereby Athe noses project in the same direction. By use of these stretchers, standard 9" straights can be used to complete the construction, if desired. In all events, the rows ta may be kept on 9" centers even thoughlSVg" stretchers are used. A further feature of the leftand right-hand straights is that they may be formed in any suitable length whereby the transverse rows 8a may be spaced as desired.

Also. noses may be provided on both sides of the stretchers, as shown at Ila, Fig. 7. Buch a construction is advantageous because it permits regulation of the size of the vertical ilue opening within rather wide limits, using standard straights and no special shapes other than the stretchers.

Since the stretcher courses 5, which separate the courses l, have no transverse members, longitudinal openings are formed which are open from end to end of the checker-work between the courses l. 'Ihe arrows in Fig. 2 indicate typical examples of these openings which extend the width and length of the separate iiues of the checker-work. To expedite the lancing, and thereby the cleaning, of the checker-work, I prefer to provide at least one course la, and preferably several spaced courses, of the stretchers 2 that are appreciabiy thicker than the others. This facilitates the intraduction of steam or air pipes. or other cleaning apparatus. into the checker-work so that the accumulated dust can be easily and rapidly removed from the surfaces of the checker-work without structural change thereof. Since the thickness of the stretchers governs the height of these vertical flue openings. it will be seen that these nues can be varied in height, particularly for lancing purposes. Also, courses la of such thicker stretchers may be disposed as often as need be to provide enough horizontal flues for adequate lancing. Thus, instead.' of being disposed as shown. courses la may be alternated with the thinner stretcher courses to provide a substantial number, say i'ive to seven, of horizontal lancing i'iues at the top of the structure.

The checker-work construction provided by the invention permits the ready insertion of steam or air pipes therein and is designed to allow the ejected steam to directly impinge on a large area of the surface thereof, i. e., this being a good method of cleaning checker-works. By providing a plurality of separate nues in my checkerwork, I not only keep eddy currents to a minimum, but also facilitate the cleaning thereof by permitting steam pressure to be built up in the separate nues due to the relatively small volume thereof.

A particular advantage of this construction is that the checker-work is composed largely of straights. 'I'hese can be molded with vacuum to provide high density bricks with consequent maximum capacity for heat storage. High pressure molding is not applicable to irregularly shaped bricksvso that the potential heat storage of the checker-work provided by this invention is raised by utilizing a large proportion of straights in its construction. 'Ihese dense bricks also provide a high weight of checker brick per cubic foot of checker volume. Since the majority of the bricks used in this invention are of ordinary rectangular shape, e. g.. standard straights, and the positioning bricks are adapted to receive the rectangular bricks, the checker-work is easily constructed. and, once built, of a solid, durable nature.

'I'he provision of a large number of standard straights permits the use of a relatively large volume of brick per cubic foot of checker chamber. This, in turn. provides a large area of heat transfer surface per cubic foot of checker chamber.

The staggered i'iue openings through the checker-work 2 function to distribute the gases over the surfaces of the checker-work. 'I'his provides ample opportunity for the absorption of heat by the checker brick from the heated gases, or the release of heat to incoming air. 'I'hus full advantage can be taken of the potential heat storage capacity of the checker-work. At the same time, the transient gases only directly impinge on the bottom (or top) surfaces of the straights forming the rows Ia. This means that there is only a minimum opportunity for accumulation of dust in the checker-work.

Various modifications are permissible. For instance. walls 8 may be built from SX45/2 straights which are 3, 2% or 2 inches thick, orof. other thicknesses. As the thickness is reduced, the

brick are laid on smaller flue centers, thus increasing the number of fiues which increases the area of exposed heat-exchanging surface.

Other advantages also accrue from the invention. Among them reference may be made to ease of stacking standard shapes, and high salvage recoveries in rebuilding checkers built in accordance with the invention.

According to the provisions of the patent statutes, I have explained the principle and construction of my invention, and have illustrated and described what I now consider to be its best embodiment. However, I desire to have it understood that, within the scope'of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A regenerative checker-work comprising the combination of a plurality of courses formed from straights arranged in spaced parallel rows, intermediate courses of stretcher brick disposed between adjacent rows of said straights and forming therewith a-plurality of vertical walls adjacent pairs of which cooperate to form separate ilues, and straights extending between said parallel rows of straights for exposure to gases passing through said ues.

2. A regenerative checker-work comprising the combination of a plurality of courses comprising aligned and abutted straights arranged in spaced parallel rows, and straights extending between said rows; and intermediate courses of stretcher brick disposed between and in alignment with adjacent pairs of said rows and forming vertical walls therewith adjacent pairs of which form separate vertical ilues, the straights extending between said rows in any course being ystaggered relative to those in the next adjacent courses, and said stretcher brick forming passages open from end to end of the fiues.

3. A regenerative checker-work comprising the combination of a plurality of courses comprising aligned and abutted straightsarranged in spaced parallel rows, and straights extending between said rows; and intermediate courses of stretcher brick disposed between and in alignment with adjacent pairs of said rows and forming vertical walls therewith adjacent pairs of which form separate vertical ilues, said stretcher brick forming horizontal passages open from end to end of the ilues and being provided with nose portions extending into the iiues.

4. A regenerative checker-work comprising the combination of a plurality of courses comprising aligned and abutted straights arranged in spaced parallel rows, and straights extending between said rows; and intermediate courses of stretcher brick disposed between and in alignment with adjacent pairs of said rows and forming vertical walls therewith adjacent pairs of which form separate vertical iiues, the straights extending between said rows in any course being staggered relative to .those in the next adjacent courses, said stretcher brick forming passages open from end to end of the ues, and said stretcher brick being provided with nose portions that protrude into the fiues and distribute transient gases over the surfaces of the checker-work.

5. A regenerative checker-work comprising the combination of a plurality of courses comprising aligned and abutted straights arranged in'spaced parallel rows, and straights extending between said rows; and intermediate courses of stretcher brick disposed between and in alignment with adjacent pairs of said rows and forming vertical walls therewith adjacent pairs of which form separate vertical iiues in the checker-work, said stretcher brick having longitudinal groovesinboth the top and bottom surfaces thereof engaging with the straights forming said courses, and said intermediate courses positioning said courses of straights in spaced relation and forming passages between said courses open from end to end ofthe fiues.

6. A regenerative checker-work comprising the combination of a plurality of courses comprising aligned and abutted straights arranged in spaced parallel rows, and cross straights extending between said rows; and intermediate courses of stretcher brick disposed between and in alignment with adjacent pairs of said rows and form- .ing vertical walls therewith adjacent pairs of which form separate vertical ilues in the checkerwork, said stretcher brick having longitudinal grooves in both the top and bottom surfaces thereof which engage with the straights forming said courses, and having on both faces transverse grooves receiving ,said cross straights, said intermediate courses positioning said courses of straights in spaced relation and forming passages therebetween open from end to end of the ues, and the straights extending between said rows in any course being staggered relative to those in,

the next adjacent courses.

7. A regenerative checker-work comprising the combination of a plurality of courses formed from aligned and abutted straights arranged in spaced parallel rows, and cross straights extending between said rows; and intermediate courses of aligned and abutted stretcher brick disposed between and in alignment with pairs of said rows from adjacent courses of straights and forming vertical walls therewith, adjacent pairs of the walls forming separate vertical fiues in the checker-work, said stretchers having longitudinal grooves in both the top and bottom surfaces thereof engaging with and positioning the straights forming said rows and having on both faces transverse grooves receiving said cross straights, said intermediate courses positioning said courses in spaced relation to form passages therebetween open from end to end of the iiues, and said stretchers being provided with noses protruding into the flues and distributing transienl gases over the surfaces of the checkerwor 8. A regenerative checker-work comprising the I verse grooves in one surface thereof intermediate the extremities of said stretchers and recessed portions in the opposite surface thereof at the extremities of said stretchers engaging with and positioning said cross straights, adjacent recessed portions forming transverse grooves at the ends of said stretchers when said stretchers form said intermediate courses, said transverse groovesy thereby staggering said cross straights in any course relative to those in the next adjacent courses, and said intermediate courses positioning said courses of straights in spaced relation to form passages therebetween open from end to end of the'flues.

9. A regenerative checker-work comprising the combination of a plurality of courses formed from aligned and. abutted straights arranged in spaced parallel rows, and cross straights ex tending between said rows; and intermediate courses of aligned and abutted stretcher brick disposed between and in alignment with pairs of said rows from adjacent courses of straights and forming vertical walls therewith, adjacent Apairs of the Walls forming separate vertical ues in the checkerwork,.said stretchers having longitudinal grooves on the top and bottom surfaces receiving and positioning the straights forming said rows and having transverse grooves in one surface thereof intermediate the extremities of

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