US3146909A

US3146909A - Feeding apparatus for powdery materials

Info

Publication number: US3146909A
Application number: US145314A
Authority: US
Inventors: Sawada Yasuhiro
Original assignee: Yawata Iron and Steel Co Ltd
Current assignee: Yawata Iron and Steel Co Ltd
Priority date: 1961-10-16
Filing date: 1961-10-16
Publication date: 1964-09-01
Anticipated expiration: 1981-09-01

Description

SePf- 1, 1954 YAsUHlRo sAwADA 3,146,909

FEEDING APPARATUS FOR PowDERY MATERIALS Filed oct. 1e, 1961 s sheets-sheet' 1 INVENTOR Yosuhro Sowodo ATTORNEYS Sept l, 1954 YAsuHlRo sAwADA 3,146,909

FEEDING APPARATUS FOR POWDERY MATERIALS 3 Sheets-Sheet 2 Filed OCT.. 16, 1961 INVENI` OR Yosuhro Suwado' ATTORNEY S sept 1 1964 YAsUHlRo sAwADA 3,146,909

FERDING APPARATUS RoR RowDRRY MATERIALS 3 Sheets-Sheet 3 Filed Oct. 16, 1961 INVENIOR United States Patent O 3,146,909 FEEDENG APPARATUS FOR WBERY MATERlALS Yasuhiro Sawada, Kokura, Fukuoka Prefecture, .'iapan, assigner to Yavvata Iron & Steel Co., Ltd., Tokyo, Japan, a corporation of .iapan Filed Get. 16, 1961, Ser. No. 145,314 3 Claims. (Cl. 222-55) This invention relates to a feeding apparatus for powdery materials. More particularly it relates to a material feeding apparatus in a Dwight-Lloyd type sintering machine.

The conventional feeding apparatus in the Dwight- Lloyd type sintering machine comprises a feeding trough, a reflecting plate against which raw material fed through said feeding trough is to strike, a how-down plate and a cut-of`f plate for cutting the fed material. In such apparatus, the material to be sintered which is fed in through the feeding trough will strike against the reflecting plate, will slide on the flow-down plate, will be fed onto a pallet in the sintering machine and will be cut off by a vertical cut-off plate. Therefore, the quantity of the fed material must be regulated by varying the speed of the sintering machine by artificially observing the quantity of the fed material. However, with such artificial regulation, it is impossible to satisfy the following points which are the most important factors in the sintering operation:

(1) The charge layer should be fluffy and well ventilated.

(2) The charge layer of the raw material after it has been fed and cut off should be uniformly horizontal.

(3) Much of the fine powdery material and a fuel part of a light specific gravity should be floating up adjacent the surface layer of the charge layer.

Further, it is diiicult to make the speed of the sintering machine and the quantity of the fed material match each other. Any artificial regulation will either bring about an excess charge of the fed material, in which case a large amount of coarse powder will appear in the surface layer or, on the contrary, the quantity of Jthe fed material will become so small that the charge layer of the raw material will become lower than the forward end of the cut-off plate and recesses will be formed on the surface of the fed material layer. Therefore, the ventilation will become non-uniform. Thus, results worse than in the case of heavy charges have been brought about and the state most undesirable to the sintering process has often been caused.

If the ventilation of the charge layer is obstructed or is made non-uniform and many coarse particles appear in the surface layer of the charge as mentioned above, the ignition yield will be reduced and, at the same time, the fall of the sintering combustion zone will be delayed considerably. Thus not only is the production reduced but also the quality deteriorates.

The present invention has eliminated the above described defects.

An object of the present invention is to provide an apparatus for making the amount of a powdery raw material fed to a powdery layer conveyer uniform.

A further object of the present invention is to provide an apparatus for obtaining a layer of conveyed raw material of a constant layer height by automatically controlling the speed of the conveyer by detecting the layer height of the conveyed powdery material.

Therefore, according to the present invention, a fluffy ventilative charge layer can be obtained, a larger amount of a raw material containing fine powder or large fuel parts will fioat up to the top layer of the charge layer due to the multistage system, and thus the ignition yield llib@ Patented Sept. l., 1964 ICC will increase, and thereby the fall of the sintering combustion layer can be made uniform and favorable, the production can be increased and, at the same time, the quality of the product can be improved.

Other objects of the present invention will be understood from the following explanation and the accompanying drawings. In the drawings:

FIGURE l is a cross-sectional view of an apparatus which operates by a conventional method.

FIGURE 2 is a perspective view of an apparatus of the present invention.

FIGURE 3 is an end elevation view of the apparatus of FIG. 2.

FIGURE 4 is a cross-sectional view, partly broken away, of the apparatus of FIG. 2.

FIGURE 5 is a cross-sectional view, on an enlarged scale, of a part of the apparatus of FG. 2.

FIGURE 6 is a perspective view of another embodiment of the present invention.

FIGURE 7 is a cross-sectional view on an enlarged scale of a part of the apparatus of FIGURE 6.

The present invention will be described in detail in the following specification.

With a view to attaining the above mentioned objects, I have devised a two-stage system wherein the amount of the fed raw material can be easily detected by being converted to the layer height. That is tosay, first there is a sloping plate for the raw material to the forward end of which several detecting plates for detecting the height of the fed raw material layer are rotatably loosely fitted. The detecting plates are further loosely fitted to the arms of a detector by regulating rods. The movement of the detecting plates rotating up and down from a lower limit level a through a median level b to an upper limit level c in response to the height of the fed material layer is transmitted as an angle to the detector by the regulating rods and arms and a signal is transmitted to an automatic control device in order that the amount of the fed material may always be in an optimum thickness layer. Second is a cut-off plate, inclined at an angle (which is not limited) of 45 degrees to the detecting plates and having the lower edge lower than the lower limit level a for lightly and uniformly stroking the top part of the fed material layer detected and regulated by the detecting plates to make the surface thereof even.

By means of this two stage system, what has heretofore been regulated only artificially can now be easily detected by providing a detecting device in the first stage. Thus, by connecting said detecting device with the automatic control device, the defects of the conventional method have been basically eliminated.

The present invention shall now be described in detail with reference to the drawings.

FIGURE 1 is a cross-sectional view of an apparatus operating in a conventional method. Such apparatus consists of a feeding trough lili, a reiiecting plate 4S against which a raw material 43 fed in through said feeding trough is to strike, a flow-down plate 46 and a cut-off plate 47 for cutting the fed material 43. In such a conventional apparatus, the raw material 4S to be sintered which is fed in through the feeding trough 44 will strike against the reflecting plate 45, will slide on the flow-down plate 46, will be fed onto a pallet 419 in the sintering machine and will be cut off by a vertical cut-off plate 47. According to the present invention, as shown in FIGURE 5, for example, a detecting plate 1 rotatably mounted at its upper end on a rotatable bearing 38 on the forward end part of a sloping plate 27 is provided on the lower part with a pivot 43 to which is loosely pivoted one end of a regulating rod 16. The purpose of inclining the forward end of the detecting plate l toward the feeding side as in the drawing is so that it will receive most of the resistance of the fed material 24 and to make it respond to the resistance of the fed material with greater sensitivity than if it were not inclined. The detecting plate is not to be limited to this form but may be in any other proper form. The regulating rod i6 loosely pivoted at one end to the detecting plate lt is loosely pivoted at the other end to an arm lli of a detector 6 by means of a loosely fitting pin 33. The lengths of the regulating rod 16 and arm ll are adjustable. By varying the length of the regulating rod 16, the height of the charge layer b can be regulated with respect to the forward end of the cut-off plate 23 so that it is an optimum. By varying thc length of the arm l1, the range of thickness of the charge layer, that is, the range or" the upper limit c of the layer thickness and the lower limit a of the layer thickness which is detected can be regulated. Needless to say, a regulating device such as is mentioned above can be contained in the detector.

When such device is provided rst in sequence and is connected with the automatic control device, the optimum layer b will always be maintained for the forward end of the cut-off plate 23 and the top of the fed material layer detected and regulated will be lightly, uniformly and horizontally cut with the forward end of the cut-off plate 23.

The operation of the present invention shall be explained with reference to FIGURES 4 and 5. The raw material 24 to be sintered which is shaken out by the swinging spout 25 will strike against the back plate 26, will slide on the sloping plate 27 and will be fed onto the pallet 2l of the sintering machine. Then, as the pallet 2 of the sintering machine is progressing in the direction indicated by the arrow, the fed material 24 will strike against the detecting plates l, 2, 3, 4 and 5 (which may be present in any number depending on the deformation of the charge layer) loosely rotatably mounted, for example, by rotary bearings 3S, 39, 4), 41 and 42, respectiveiy, on the forward end of the sloping plate 27 and will push up the respective detecting plates l, E, 3, 4 and 5. In such case, if the amount of the material 24 to be sintered Which is fed is too great, the detecting plates il, 2, 3, 4 and 5 will be pushed up high. But, on the contrary, if insufficient material is fed, the detecting plates will tend to come down and to become vertical due to their own weicht or any external force. The regulating rods 16, i7, 1:2, 19 and 2t) for transmitting the movements of the detecting plates i, 2, 3, 4 and 5, which detect the quantity of the fed material by converting it to the layer height, respectively, to the detectors 6, 7, 8, 9 and 10 are each loosely rotatably mounted at one end to said detecting plates by means of loosely fitting pins 213, 29, 3f?, 31 and 32 and at the other end to the arms li, l2, 13, 14 and 15 of the detectors 6, 7, 8, 9 and Mi by means of loosely fitting pins 33, 342-, 35, 36 and 37, respectively. Therefore, as shown in FIGURE 5, when the' quantity or" the fed material 24 increases, the detecting plates l, 2, 3, 4 and 5 will be pushed up high, therefore the presence of the top of the layer at the upper limit c will be detected and the arms lll, 12, 13, 14 and 15 of the detectors 6, 7, S, 9 and i0 will be rotated upward by the regulating rods i5, i7, 18, l@ and 2t), respectively. On the contrary, when the quantity of the fed material 24 decreases, the detecting plates ll, 2, 3, 4 and 5 will come down, therefore presence of the top of the layer at the lower limit layer a will be detected and the arms 11, l2, 13, 14 and l5 of the detectors 6, 7, 8, 9 and 1t) will be rotated downward through the regulating

rods

16, 17, 18, 19 and 2f?, respectively. The rotary angle transmitted mechanically by such following action will be detected as an electric signal by the

detectors

6, 7, 3, 9 and 10 and the signal caused by the top of the layer reaching the upper limit c, the proper level b and lower limit a will be transmitted to the automatic control device. That is to say, the controlled layer height will be detected by the detecting mechanism (detecting plates and detectors), the set layer height and controlled layer height will be compared with each other and the difference will be detected as a signal (either for the upper or lower limits) and will be transmitted to the automatic control device in which the speed of the controlling object (sintering pallet or raw material feeding device) will be regulated and will be automatically controlled until the set layer height and controlled layer height coincide with each other, that is, until the signal indicating a difference between these two heights is no longer caused. The charge layer thus regulated so as to be the optimum layer by the detection in the rst stage will be further stroked by the cut-off plate 23 provided after the detecting plates and inclined at the forward end at an angle (which is not limited) of 45 degrees to the detecting plates so that the top of the charge layer most important to the sintering operation may be made light, uniform and horizontal. This system is of a two-stage type characterized in that a detecting mechanism is provided on the first stage side and the material is further cut uniformly and horizontally on the second stage side. The detecting mechanism may be of any type and is not limited to the detecting plates.

Further, as a modification of the present invention, when the above mentioned two-stage system is made into a multi-stage system of three or more stages, the object of the invention can also be attained. That is to say, the amount of the fed material can be better regulated to give a constant layer height by the multi-stage system. First in sequence, as in the two stage system described above, are several detecting plates for detecting the height of the layer of the fed material which plates are loosely mounted on the forward end part of a plate which is also a iiow-down plate for the raw material. The movement of the detecting plates to which the arms of a detector are connected by regulating rods, and which plates rotate up and down from the lower limit level a to upper limit level c in response to the height of the fed material is transmitted as an angle to the detector through the regulating rods and arms and then a signal is transmitted from the detector to an automatic control device so that the layer of the fed material may be always kept optimum. Second is a rst cut-off plate inclined at an angle (which is not limited) of 45 degrees to the detecting plates and having the lower edge theerof at a level slightly lower than the lower limit level a of the detecting plates. After the first cut-off plate is positioned a second or finishing cut-off plate with the lower edge thereof at a slightly higher level than the level of the first cutoff plate and at a slightly lower level than the lower limit level a. This system is called a three stage system. If three cut-off plates are provided in sequence, the system is called a four stage system.

The raw material which is removed from the layer of material by the first cut-off plate accumulates between the first and second cut-off plates and overflows the first cutolir plate and is fed in a thin layer, usually of 5-10 mm. in thickness, but not limited to this thickness, to the layer of material passing between the first and second cut-off plates, and the thin layer usually corresponds to the difference in the height of the bottom edges of the cut-off plates. If there is a third, cut-off plate, the second cut-off plate will act in the same manner to spread a thin layer of raw material eut from the moving layer thereby. The ignition yield of such a thin layer is greatly improved, because this thin layer is Fluffy and the uppermost layer thereof is mostly fine powder and the fuel portion thereof has a light specific gravity.

This shall be further explained with reference to the drawings. In FIGURE 7, the detecting plate 1 is loosely rotatably mounted at the upper part thereof on the forward end of the flow-down plate 27 by a rotatable bearing 33 and has mounted on the lower part a pivot 43 on which is loosely rotatably mounted the regulating rod 16. The regulating rod 1 6 is loosely rotatably mounted at one end on the pivot 43 by a loosely fitting pin 28. The shape of the forward end of the detecting plate 1 as shown in the drawing is only to meet the resistance of the fed material 24 and to make the detecting plate respond sensitively thereto. The detecting plate is not to be limited to this form but may be in any other form. The regulating rod 16 loosely rotatably mounted at one end on the detecting plate l and is loosely rotatably mounted at the other end on an arm 11 of a detector 6 by means of a loosely tting pin 33. The lengths of the regulating rod 16 and arm 11 are adjustable. By adjusting the length of the regulating rods 16 and the detector response, the layer of material 24 being fed can be kept to the optimum level b. The material regulated to the optimum thickness level b on the first stage side will be stroked by the rst cut-off plate 22 so as to be of a uniform horizontal thickness. However, the slight material remaining after being stroked due to the delay caused at the time of the automatic control will be accumulated and will therefore overflow the cut-off plate 22. This overflowing material will enter a pocket 50 located between the cut-olf plate 22 and the second or finishing cut-off plate 23 and will be gradually fed to the layer 24 in a thin layer with a thickness of 5 to 10 mm. coming out after being stroked by the cut-oftr plate 22. Thus, by using as many as three or four stages, it is possible to feed a raw material rich in ne powder and fuel parts to the top part of the layer of the fed material and to remarkably improve the ignition yield.

The present invention has been explained in the above with reference to a Dwight-Lloyd type sintering apparatus. However, the present invention is not to be limited thereto but can be applied to any conveying apparatus for powdery materials for the same purpose as the present invention. The present invention includes such application, too.

What I claim is:

1. A granular bulky material handling apparatus for automatically regulating the height of a layer of material being fed on the conveyor of a sintering machine, said apparatus comprising a swinging spout from which said granular bulky material is poured in a stream, a back plate sloping in one direction below said spout against which said material pouring from said swinging spout strikes, a sloping plate sloping in the opposite direction below the lower end of said back plate and on which the material from said back plate slides down onto a conveyor, a plurality of detecting plates the upper end of each of which is freely rotatably mounted on the lower end of said sloping plate for detecting the height of said material on the conveyor by stroking said material beneath the lower edge of each plate, said plates being rotatable with the lower edge rotating up and down in response to the height of said material being stroked, a plurality of regulating rods each having one end thereof freely pivoted to one of said detecting plates, a plurality of arms to which the other ends of said regulating rods are respectively connected, the lengths of said regulating rods and arms being adjustable, a plurality of detectors to which the arms are respectively connected for transmitting the movement of said detecting plates during their rotating up and down in response to the detected height of said material as an angle and which are adapted to transmit said movement of said detecting plates to an automatic control device as a signal for regulating the speed of the conveyor according to a transmitted signal by accelerating said speed when the lower limit of said fed material is detected in the respective areas of said detecting plates and slowing said speed when the upper limit is detected, to keep the height of the layer of said material to an optimum, and at least one fxedly mounted cut-off plate behind said detecting plates, the lower edge of which is below the lower edge of said detecting plates when said detecting plates are in the lowermost position thereof and being inclined at an angle to said detecting plates and which strokes the surface of said material layer already regulated `as to thickness by the variation of the speed of said conveyor to obtain a uniform layer thickness.

2. An apparatus as claimed in claim 1 in which there is only a single cut-olf plate.

3. An apparatus as claimed in claim 1 in which there are a plurality of cut-off plates in succession, each having the lower edge thereof at a level lower than the lower edge of the detecting plates when said detecting plates are in the lowermost position, and each succeeding cut-olf plate has the lower edge thereof at a slightly higher level than the level of the lower edge of the cut-olf plate immediately preceding it.

References Cited in the file of this patent UNITED STATES PATENTS 2,590,968 Hill Apr. 1, 1952 2,708,503 Arnold May 17, 1955 2,920,355 Clark Jan. 12, 1960 3,062,355 Sawada Nov. 6, 1962 FOREIGN PATENTS 168,907 Sweden Oct. 13, 1959 712,893 Great Britain Aug. 4, 1954

Claims

1. A GRANULAR BULKY MATERIAL HANDLING APPARATUS FOR AUTOMATICALLY REGULATING THE HEIGHT OF A LAYER OF MATERIAL BEING FED ON THE CONVEYOR OF A SINTERING MACHINE, SAID APPARATUS COMPRISING A SWINGING SPOUT FROM WHICH SAID GRANULAR BULKY MATERIAL IS POURED IN A STREAM, A BACK PLATE SLOPING IN ONE DIRECTION BELOW SAID SPOUT AGAINST WHICH SAID MATERIAL POURING FROM SAID SWINGING SPOUT STRIKES, A SLOPING PLATE SLOPING IN THE OPPOSITE DIRECTION BELOW THE LOWER END OF SAID BACK PLATE AND ON WHICH THE MATERIAL FROM SAID BACK PLATE SLIDES DOWN ONTO A CONVEYOR, A PLURALITY OF DETECTING PLATES THE UPPER END OF EACH OF WHICH IS FREELY ROTATABLY MOUNTED ON THE LOWER END OF SAID SLOPING PLATE FOR DETECTING THE HEIGHT OF SAID MATERIAL ON THE CONVEYOR BY STROKING SAID MATERIAL BENEATH THE LOWER EDGE OF EACH PLATE, SAID PLATES BEING ROTATABLE WITH THE LOWER EDGE ROTATING UP AND DOWN IN RESPONSE TO THE HEIGHT OF SAID MATERIAL BEING STROKED, A PLURALITY OF REGULATING RODS EACH HAVING ONE END THEREOF FREELY PIVOTED TO ONE OF SAID DETECTING PLATES, A PLURALITY OF ARMS TO WHICH THE OTHER ENDS OF SAID REGULATING RODS ARE RESPECTIVELY CONNECTED, THE LENGTHS OF SAID REGULATING RODS AND ARMS BEING ADJUSTABLE, A PLURALITY OF DETECTORS TO WHICH THE ARMS ARE RESPECTIVELY CONNECTED FOR TRANSMITTING THE MOVEMENT OF SAID DETECTING PLATES DURING THEIR ROTATING UP AND DOWN IN RESPONSE TO THE DETECTED HEIGHT OF SAID MATERIAL AS AN ANGLE AND WHICH ARE ADAPTED TO TRANSMIT SAID