US876602A - Cement-burning furnace. - Google Patents

Description

PATENTED JAN. 14, 1908 W. B. SNYDER. CEMENT BURNING FURNACE.

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APPLIOATION FILED MAR.11, 1907.

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PATENTED JAN. L4; 1908.

WE. SNYDER. CEMENT BURNING FURNACE.

APPLICATION FILED MAR. 11, 1907.

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i 1||a|{ am 5 z a r/N flxb my m w vi w/ No. 876,602. PATENTED JAN.14, 1908.

W. E. SNYDER.

CEMENT BURNING FURNACE.

APPLIGATION FILED MAR.11, 1907.

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WILLOUGHBY ELWOOD SNYDER, OF NAZ ARETH, PENNSYLVANIA.

CEMENT-BURNING FURNACE.

Specification of Letters Patent.

Patented'Jan. 14, 1908..

Application filed March 11 1907- Serial No- 361.640.

Cement-Burning Furnaces, of which the following is a specification.

My invention relates to furnaces designed primarily for the calcination of cement and generally for the treatment at high temper- 5 atures of anv cognate materials.

My object is to provide a furnace for the above purposes, wherein electricity constitutes the heat generative agent, and which.

shall be durable and economical in construc- These results I accomplish by the means herein described and shown in the accompanying drawings, in

Figure 1 is a view of the furnace in vertical section, omitting the feed and draftcompelling devices, and showing the rotary hearth with the means for actuating the same, the stationary hood, the arc-electrodes, the electro-magnets and the means for raising and lowering the hearth relatively to the arc-electrodes. Fig. 2 is a view of therfurnace in plan, showing the rotary hearth with its supporting spider, the hood, the arc-electrodes, the electro-magnets, the feed pipe,

thc stock or draft-compelling means, the

scraper and the apron therefor. Fig. 3 is a detail view in side elevation, partly in vertical section and partly in perspective, of the hearth and hood at the point of charge and discharge, showing the feed pipe, the

stack, the scraper and the apron. Fig. 4 IS a detail-view in cross section, of the hearth showing the scraper and the apron. Fig. 5

v is a detail view, in plan, of the means for estabhshing electrical connection between the ment of the electro-magnets.

electro magnets and the power shaft, as shown in Fig. 1. Fig. 6 is a detail view, in elevation, showing. an alternative arrange- Fig. 7 is a detail view, in. elevation, of the shutter or slide at the charging end of the hood, showing the means for raising and lowering the shutter.

In Fig. 1 the spider or spoked wheel 1 car ries the annular reservoir 2 from the bottom of which rises the vertical support 3 carrying the continuous annular hearth 4 with its top 5 composed of firc-briclr or other suitable heat-resisting material. The vertical sup- 6 and its plates 9 are continuous save at the point of charge and discharge shown in Fig. 2 and hereinafter described; and the space included by the hood above the hearth should be such as to produce the necessary reverberatory action of the heat of the arcs, hereinafter described, located within the hood above the hearth against the charge thereon.

At intervals in the hood 6 openings in the opposite sides thereof are formed, as shown in Figs. 1 and 2, for the introduction of aresupporting electrodes or carbons, the positive carbons being indicated by the numeral 10 and the negative by the numeral 11. The positive and negative carbons are arranged in sets respectively, as shown in Fig.2, and are staggered in such wise as to lay an arc across the entire width of the hearth. Each set of positive electrodes is provided with any,suit able mechanism (not shown) for automatically advancing or feeding the carbons to preserve an arc of the requisite constancy of energy. For this purpose the mechanism. shown and described in Letters Patent No. 816,753, dated April 3, 1906, granted to me for cement burning furnace may be employed.

The hearth 4 with its spider 1 is rotated by the vertical shaft 12 mounted in the bearing .13 in the frame 8 and upon the shoulder on the bearing 14 of the threaded sleeve hereinafter described. The pulley wheel 16 indicatcs any suitable means for rotating the shaft, spider and hearth.

Upon the hood 6 are located the electromagnets 17. These communicate with the shaft 12, Fig. 1, by means of the arms 29, one end of each arm being secured to an electromagnet and the other end being secured to the split ring 30 surrounding the shaft 12. Electrical connection with the shaft 12 is secured by the brushes 31 carried by the ring 30, as shown in plan in Fig. 5; Thus, refer-- ring to Fig. 1, the magnetic flux passes from the electro-ma-gnets l7 downward through the hood and hearth, is thence conducted llt through the arms of the spider or spoked wheel 1 to the shaft 12, ascends the shaft 12 to the brushes 31 and thence through the ring 30 and arms 29 back to the electro-magnets 17; The course of the current is indicated by the dotted arrows in Fig. 1. The function of the pairs of electromagnets above described is to intensif the calcining action of the arcsgenerate between the carbon points hereinabove described.

The means for feeding the cement or other material upon the hearth are indicated in Fig. 2 and shown in detail in Fig. 3. It consists of the feed pipe 20 opening directly upon the hearth at thecharging end of the hood, the casing 21 forming the lower end of a suitable bin or hopper containing the material to be calcined, and the notched feed cylinder 22 adapted to rotate in the casing 21. By the rotation of the feed cylinder 22,by any suit: able mechanism (not shown) an'intermittent feed of the material is obtained from the hopper and casing 21 into the upper end of the feed pipe 20 whence it is deposited upon the hearth. at the charging end of the hood. An intermittent deposit upon the hearth of the material to be calcined is desirable for the reason that a continuous charge or deposit becoming vitrified into a more or less solid and continuous mass might tend to become blocked or jammed within the hood, particularly at the exit or discharge end thereof where the vitrified or calcined product is turnedoif the hearth by the scraper 23 hereinafter described.

In Fig. 2 the hood 6 is seen to be continuous save for th'e space between its charging and discharge ends. In this space is arranged the scraper 23, disposed diagonally across the l-i'earth and secured either to the ends of the hood or to the straps supporting the same, as shown in Figs. 2 and 3. To prevent any portion of the calcined product from dropping into the reservoir 2 at this point as it is scraped or diverted from the hearth the stationary apron 24 is secured either to the ends of the hood or otherwise supportedfiasshown in Fig. 4, the lip of the apron extending partly beneath the hearth in such wise that the calcined product removed from the hearth by the action of the scraper is discharged over the apron without danger of blocking up the reservoir.

In Figs. 2 and 3 the stack 25 represents any suitable draft-compelling means. It communicates with the hood near the charging or feed end thereof and is designed to be provided with a fan or blower (not shown) of any well known form to create an up-draft in the stack. The inlet or chargingend of the hood is closed by the shutter or slide 26 Fig. 7, which allows of an openin between its lower edge and the surface of t e hearth sufficient to permit the material fed thereon by the pipe 20 to enter the hood. The exit or discharge end of the hood is open. Thus the up-draft created in the stack 25 by the blower or fan causes a current of air to be drawn in shaped compartments of the reservoir 2, Fig.

1, are partially filled with any suitable fluid, such as a heavy oil and the plates 9 extending down from each side of the hood into said liquid render the hood continuously air-tight save at the charging and discharge ends thereof. Thus no air is drawn in under the edges of the hood to interfere with the circulation above described. This arrangement of parts serves the further urpose of conserving as far as possible the fieat within the hood.

In the use of my furnace for the calcination of cement or other cognate materials it may become desirable or necessary to employ diflerent degrees of heat for the treatment of different substances or of different grades of the same substance. cure by the means shown in Fig. l. The lower end of the vertical shaft 12 is provided with a threaded sleeve 26 set-screwed thereto and controlled by the wheel 27 mounted upon the bearing'28. By rotating the wheel 27 the shaft 12 may be lowered, an opening in the base 15 being provided for the purpose. This lowers the hearth, increasing the space between the charges thereon and the carbon oints above and likewise increasing the volaction of the electrodes from the moment it enters the charging end of the hood it may be over-burned and the product thus may be deteriorated. By the arrangement shown in Fig. 2 the material entering the charging end of the hood is subjected to the reverberatory heat of the hood and heart'h, which is least'at the point of entrance and increases as the hearth with its charge approaches theiirst set of electrodes. The distance between the first set of electrodes and each succeeding set progressively diminishes, thus increasing both the direct and reverberatory heat to which the charge is sub'ected in its circulation through the hood rom the charging end to the discharge end.

This adjustment I scv in Fig. 6 I have indicated an alternative tutes an improvement thereon.

magnetic re-inforcement of the calcining action of the carbons. In this arrangement the spider 1 carries the annular reservoir 2 and the hearth. 4 with its fire-brick covering 5 Air tightness at the sides of the hood 6 is secured by an extension of the sides thereof into the reservoir. Th disposition of the carbons 10 and 11 is as 'hereinbefore described. The electro-magnet 17 is located, as before, above the hood and is provided with the head 32 which projects downward through the top of the hood as shown. The bent arm 33 passes from the electro-magnet l7 outward, downward and upward to a point immediately below the hearth, providing a means whereby a continuous circulation of the elec tro-magnetic current may be obtained for the purpose of re-inforcing the action of the carbons, as hereinbefore described.

In Fig. 7 is shown a means for adjusting the shutter 26 at any desired height and thus partly closing the charging end of the hood. To one end of the arm 34, pivoted upon the support 35 is booked the chain 36 attached to the top of the shutter, and the chain 37, one end of which is secured to the top of the, hood, is hooked to the dther end of the arm.

Having thus set forth in detail the component parts of my invention I shall now describe the principle of my furnace together with its mode of operation. To that end I shall repeat a portion of the matter contained in the specification of j Letters Patent No. 816,753, dated April 3, 1906, granted to me for cement burning furnace, inasmuch as my present invention consti- In the first place, I avoid actual penetration of a charge or mass of cement mixture to be treated by the arcs or any part of the arcs, which may prevent the manufacture of a sound cement. I employ the heatderived only by radiation, deflection or reverberation of the arcs. The arcs must be located a sufficient distance above the hearth to accommodate upon the hearth a charge disposed below, but not between the electrodes that sustain the are, it being well understood that the heat of an arc is most intense and that the hi hest degree of its intensity is located directly withinthe current of or between the electrodes supporting the are, where, as has been specified, it is, if not too intense, at least too much concentrated for its successful employment in the manufacture of cement. It is the object of my invention in part to employ such heat, free, as it is, from products of combustion deleterious to cement at its highest efficient intensity but withoutits c etionable degree or manner of concentration above referred to. To that end, 10- eating a mass of cement mixture to be treated or charged out of the line of penetr'ation by the arcs I provide'for the full and complete calcination.

arcs is directed, deflected, and'concentrated in ellieient energy against the charge upon the hearth.

In order to provide for the continuous manufacture o cement upon a hooded hearth of annular form, it is necessary, in 7 view of the fact that the immediate product of calcination in the manufacture of cement is a clinker or vitrified mass, to deposit ceuient mixture in separate charges upon the hearth, because when so deposited .they

clinker into detached portions or cakes which may, through the continuous rotationf of the hearth, be automatically swept therefrom one by one by the scraper. Further, an

advantage is derived over a continuous charging feed, in securing to the charge that perfect homogeneity of calcination which is essential to the manufacture of a sound cement. Finally, it is advantageous to the practical application of heat over an extended charge or mass to be calcined in the mamlfacture of cement but more especially in the aiplication of successive heats to separate charges, not only to make provision for the application of an abundant supply of oxygen to the cl'iarge while it is undergoing calcination, but also with especial reference to the sev. eral stages which it undergoes between initial To explain more fully, the initial application of heat to a charge of cement mixture besides expelling moisture liberates carbonic-acid gas in quantity. Consequently in order to promote combustion it is not only necessary to keep a constant supplyof oxygen at the point of combustion, but also to draw off the carbonic-acid gas and other impurities or deleterious products generated by the combustion. If, therefore, suitable draft-compelling means he provided and properly applied in the manufacture, it will serve a double purpose, both of affording'a fresh. supply of oxygen and of removing injurious products of combustion. Consequently I provide, by means of the stack communieating with the charging end of the hood, for the generation of a current of air in opposition to the direction of movement of the hearth. This provides pure air to the final combustion and conducts the current by successive stages to the'point'of initial combustion, whence the dense fumes generated by such initial combustion are conducted off through the stack, without possibility of contamination of the finished product.

While the general principle of my furnace herein described is similar to that of the furnace for which Letters Patent No. 816,753

were granted me on April 3, 1906, the means whereby that principle is practically applied have been mproved in the following particulars, viz: the means for rendering the hood air-tight throughout its extent, save at the charging and discharge ends thereof, the arrangement of the arc-electrodes in staggered sets-whereby the width of the hearth is more effectively covered by the arcs than can be done by the use of asi ngle pair of arc electrodes in place of a staggereijl set.

What I claim as my invention and desire to secure by Letters Patent isv 1. In a cement-burning furnace the combination with a rotatory annular hearth provided with a stationary reverberatory hood, of a set of arc-electrodes operatively disposed within the hood above the hearth,

the members of the set being'staggered so that the series of arcs produced between said members covers the entire width of the hearth, an electro-magnet located above said set of arc-electrodes, and means for securing a continuous current from said electro-magnet downward upon the hearth, substantially as described.

2. in a cement-lnlrningl'urnace the combination with a rotatory annular hearth, a stationary reverberatory hood inclosing the same, and draft-compelling means adapted to produce a current of air in opposition to the direction of movement of the hearth, of a set of arc-electrodes operatively disposed within the hood above the hearth, the individual carbons composing the set being staggered so as to produce a series of arcs extending diagonally across the entire width of the hearth, an electro magnet located above said set of arc-electrodes and means for securing a current from said electromagnet through the hearth, to concentrate and increase the eifect of the arc-electrodes, substantially as described.

3. In a cement-burning furnace the combination with a rotatory hearth and reverberatory hood provided with draft-compelling means adapted to produce a current of air within the hood in opposition to the direction of rotation of the hearth, of a set of arc-electrodes operatively dis osed within the hood above the hearth, t e individual carbons composing the set being staggered so as to produce a series of arcs covering the entire width of the hearth, substantially as described.

4. In a cement-burning furnace the combination with a rotatory hearth and reverberatory hood provided with draft-compelling means adapted to produce a current of air within the hood in opposition to the direction of rotation of the hearth, of a series of sets of arc-electrodes operatively disposed within the hood above the hearth, the carbons composing each set being staggered so as to produce a series of arcs covering the entire width of the hearth, the distance between each set of arc-electrodes progressively di- 'ity of sets of arc-electrodes operative minishing from the charging end to the discharge end of the hood, substantially as described. I

5. In a cement-burning furnace the combination with a rotatory hearth and reverberatory hood provided with draftsco'mpelling means adapted to produce a current of air within the hood in oppositionto the di rection of rotation of the hearth, of a series of sets of arc-electrodes operatively disposed withinthe hood above the hearth, the carbons composing each set being staggered so as to produce a series of arcs coverin the entire width of the hearth, the interva .between each set of arc-electrodes and the next progressively diminishing from the charging end to the discharge end of the hood, and means i or vertically adjusting the hearth rela.

ti'vely to the arc-electrodes, substantially as described.

6. In a cement-burning furnace the bination with a rotatory hearth and reverberatory hood provided with draft-compelling means adapted to produce a current of air within the hood in opposition to the direction of rotation of the hearth, of a series of sets of arc-electrodes operatively disposed within the hood above the hearth, the earbons composing each set being staggered to 7. In a cement-burning turnace' the combination with a rotatory hearth and reverberatory hood provided withdraft-compelling means'adapted to produce a current of air within the hood in opposition to the direction of rotation of the hearth, of a lugal- 1sposed within thehood above the heart the i carbons composing each set being staggered to reduce a series of ares covering the entire uidth of the hearth, the interval between each set of arc-electrodes and the next being progressively diminished from the charging end to the discharge end of the hood, an electro-nia net located above each set of arcelectror es, means, consisting of the threaded sleeve 26 and wheel 27, for vertically adj usting the hearth relatively to the arc-electrodes, means, consisting of the reservoir 2 and plates 9, for rendering the hood substantially air-tight throughout its extent, ascra er, an apron, and means for intermittently ceding material upon the hearth, consisting of the as C0111- .20, substantially as escribed.

8. In a cement-burning furnace, a spider, an anndlar reservoir carried thereby, an annular hearth mounted upon said reservoir, a non-rotary reverberatory hood inclosing said hearth, the sides of said hood extending downward into said reservoir, a plurality of sets of arc-electrodes operatively disposed within the hood above the hearth, the carbons composing each set being staggered to produce a series of arcs covering the entire width of the hearth and the interval between each set of arc-electrodes and the next being progressively diminished from the charging to the discharge end of the hood, a plurality of electro-magnets each of which is located upon the hood above its corresponding set of arc-electrodes,means, consisting of the shaft 12 and pulley 16, for rotating said spider, reservoir and hearth, means, consisting of the arms 29, ring and brushes 3], for securing a current from said el'eetro-niagnets downward through the hearth, and draft-compeb ling means adapted to produce a current of 3 air within the hood in opposition to the direc,

tion of rotation of the hearth,substantially as described.

9. In a cement-burning furnace, a rotatory wheel carrying an annular bifur'cate reservoir and a hearth, a non-rotary reverberatory hood suspended over and inclosing said hearth, the sides of said hood extending sets of arc-electrodes operatively disposed within the hood above the hearth, the carbons of each set being staggered, anelcctro- I WILLOUGHBY ELWOOU SNYDER.

- W tnesses: I

" ,WiLsoN E. BECK,

l\"lATTIE M. W'ooumo.

downward into said reservoir, a plurality of magnet for each set of arc-electrodes, dis posed upon the hood above the set of arc

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