US1401735A - Method for removing solids suspended in or carried by gases - Google Patents

Description

F. C. ROBERTS. METHOD FOR REMOVING SOLIDS SUSPENDED IN OR CARREED BY GASES.

APPLICATION FILED JAN-22,1921- 1,401,735. Patented Dec. 27, 1921.

4 SHEETS-SHEET l.

INVENTOR.

F. C. ROBERTS.

METHOD FOR REMOVING souns SUSPENDED IN OR CARRIED BY GASES.

APPLICATION FILED JAN. 22, I92I.

Patented Dec. 27, 1921.

4 SHEETS-SHEET 2.

FIG.

FIG. 5.

[NVE/VTOR.

F. C. ROBERTS.

METHOD FOR REMOVING SOLIDS SUSPENDED IN OR CARRIED BY GASES.

APPLICATION FILED JAN-22,19Z1- 1,401,735. Patented Dec. 27, 1921.

4 SHEETS-SHEET a.

INVENTOR W TNESSES M. Ma -flz; KW

v F. 0. ROBERTS. METHOD FOR REMOVING SOLIDS SUSPENDED IN OR CARRIED BY GASES.

APPLICATION FILED IAN-22.1921- Z 4 ir e n Patented Dec. 27, 1921,.

4 SHEETS-SHEET 4- FIG.II.

FIG.IZ.

INVENTOR. 4 WM WITNESSES the application of the method to the gaseswarren stares PATENT *OFFIQE.

FRANK C. ROBERTS, OE WYNNEWOQD, PENNSYLVANIA.

METHOD FOR REMOVING SOLIDS SUSPENDED IN OR CARRIED BY GASES.

Specification of Letters Patent. Patented Dec, 2'7, 1921,

Application filed January 22, 1921. Serial No. 439,167.

To all whom it may concern Be it known that I, FRANK C. ROBERTS, a

citizen of the United States, residing at Wynnewood, in the county of Montgomery and State of Pennsylvania, have invented or discovered new and useful Improvements in Methods for Removing Solids Suspended in or Carried by Gases; My invention relates to a novel method whereby gases which carry objectionable solids such as dust, etc., may be cleaned by the removal of said solids from the gases before they are used for their intended purpose.

While I do not limit my invention to the cleaning of the gases discharged by blast furnaces and utilized for the generationof heat, an explanation of my method, as it may be utilized in treating blast furnace gases, will serve to illustrate said method as it may be applied generally in treating gases which carry objectionable solids. The following description therefore deals with discharged by blast furnaces employed for smelting iron ore.

It is well known that the gases discharged by blast furnaces carry a very considerable quantity of dust composed of iron-ore, coke and limestone and further, that this dust, unlessremoved, is carried to the boilers and hot blast stoves where the gases are consumed, and settles on the heating surfaces of these parts, thus reducing the efiiciency of the boilers and hot blast stoves in absorbing the heat generated by the combustion of the gases. Since it is important to maintain the heating surfaces of the boilers and stoves in an eflicient condition, it be- ,comes necessary from time to time to' remove the dust from these heating surfaces, an operation which requires a considerable expenditure of money. It is therefore evident that it is desirable toremove the dust from the gases before the latter reach the places'where they are consumed.

In general, two systems for removing solids and thereby cleaning blast furnace gases are now in use, i. e., the dry and wet systems. The principal installations of the dry system consist of, (a) a receptacle of larger area than the gas pipes-leading to and from said receptacles, whereby the velocity of. the gases in passing continuously through the receptacle is reduced, and the heavier particles of dust carried by the of mats or bags through which the gases pass, the dust being held .by the mats or bags and (d) an arrangement of electrical devices placed within a receptacle, and by means of which the particles of dust become electrified and are repelled to and held on surfaces by the v resultant electrostatic force. T-he wet system of cleaning consists of various devices, whereby the gases are brought into contact with water, and the dust thereby washed out of the gases. In the wet system the thorough cleaning ofthe gases requires that 'a relatively large volume of water be supplied to the apparatus to absorb the sensible heat of the gases, otherwlse the gases leaving the apparatus will be of such a temperature that they will carry a high degree of moisture, a condition that prevents the efiicient combustion of the gases. In both the dry and wet systems now 1n use, the gases flow continuously through the cleaning apparatus.

The advantages of the-dry systems over the wet systems of cleaning are, (a) that l the sensible heat of the gases is retained,

and (b) that the dust removed from the gases and apparatus is in a dry condition in use, are based upon the'principle, that the cleaning process is performed while the gases are passing through the cleaning apparatus in a continuous flow and without interruption. It is therefore evident that a new principle and method would be applied in case the removal of solids is performed .while the gases are at rest, and during a period when thev flow of the gases'through the cleaning device is interrupted, without interrupting the flow of the gases from the blast furnace or other source of generation.

The object of my invention is'to provide a method whereby gases which carry objecttional solids may be cleaned by the removal of such solids, while said gases are at rest and without interrupting the flow of the gases from their source of generation.

In order to disclose my method and to illustrate a practical application thereof, I have shown in the accompanying drawings simple forms of apparatus whereby the invention may be utilized and in which z- Figures 1 and 2 are respectively a vertical section and plan of one form of apparatus, the section being taken on line Z Z of Fig. 2. Figs. 3, 1, and 5 are respectively a vertical section, a plan view of the top and a horizontal sectional plan of another form of apparatus, the vertical section being taken on line W WV of Fig. 4 and the horizontal sectional plan being taken on line X X. of Fig. 3. Fig. 6 shows one form of operating apparatus for valves 0 and 0 (see Fig. 1). Figs. 7, 8 and 9 are respectively a vertical section, a plan view of the top and a horizontal sectional plan of another form of apparatus, the vertical section being taken on line U U of Fig. 8 and the horizontal sectional plan being taken on line Y Y of Fig. 7. Fig. 10 shows one form of operating apparatus for valves t and 9 shown respectively in Figs. 8 and 9. Figs. 11 and 12 show respectively a vertical section and plan of another form of apparatus, and Figs. 13 and 14 are each vertical sections showing the receptacles equipped with certain devices.

Similar letters refer to similar parts throughout the several views.

Referring to Figs. 1 and 2z-A and A are vertical cylinders or receptacles equipped with conical tops and bottoms, furnished with fire brick linings a, and supported on columns I). Valves 0 and 0 arranged to close against seats d, are located respectively at the top of A and A, and are carried by rods 6 and lever f, pivoted at g', the valves, levers, etc., being so arranged that when one valve closes the other opens. Valves gi seating at Z, and carried by levers j counterweighted by 70, are located at the bottoms of A and A. D is the gas supply pipe which delivers the gas to A and A, by

branches B and B respectively. The gas leaves A and A through valves 0 and 0 respectively, pipe h and outlet C. E represents railroad cars under A and A, and into which the solids removed from the gases may be discharged through valves 2'.

The operation of the apparatus is as follow's:VVhen placing the apparatus in use the gases are delivered from the blast furnace or other source of generation of pipe D and thence admitted to A and A through branch pipes B and B, valves 0 and 0. being held open until the air in A and A has been displaced by the gases. The valve 0 is then closed and valve 6 is opened as indicated in Fig. 1, in consequence of which, the flow of gases to A stops after A is filled with gases, whereas the gases continue to flow to and through A. By this means the gases in A are brought to a state of rest and the solids suspended in the gases in A, fall to the bottom of A by the action of gravity on the solids. Valve 0 is now opened and valve 0 closed, which ,action diverts the flow-of gases from B and A to B and A. The closing of the valve 0 confines the gases in A, brings said gases to rest, and allows the solids suspended in the gases to fall to the bottom of A, by the action of gravity. In the meantime valve 0 in A being open, gases carrying solids enter A through B and force the gases from which the solids have been removed, out of A through valve 0 and pipe h to outlet C. When the gases in A from which the solids have been removed, are displaced by gases.

carrying solids, valve 0 is closed and valve 0 opened, and the flow of gases carrying solids is diverted to A thereby forcing the gases from which the solids have been removed, out of A through valve 0 and pipe k to outlet C. The described operations are repeated gases being brought to rest and the solids carried b the gases removed, alternately in A and in such manner that, after the filling ofone of the receptacles A or A with gases at the time of placing the apparatus in use, all gases delivered by the blast furnace or other source of generation to the supply pipe D, flow continuousl through the apparatus to the outlet pipe The solids-which have been deposited in the bottoms of A and A are removed from these receptacles by opening valves 2', by which means the solids are delivered to the railway cars E or otherwise disposed of. The dimensions and volume of the receptacles A and A are dependent upon the interval of time required for the solids, or such portion thereof as it is desired to remove from the gases, to fall to bottoms of said receptacles, and upon the volume of gases that it is desired'topass through the apparatus in said interval. W

In the event of it being desirable to increase the volume contents of A and A beyond that economically desirable from the standpoint of construction, it is evident that two or more receptacles may be substituted for each receptacle A and A. Figs. 3, 4: and 5 illustrate how two receptacles A and two receptacles A may be provided, instead of one receptacle A and one receptacle A. The operation of the apparatus shown in Figs. 3, 4 and 5 will be readily understood if the two receptacles A and the two receptacles A, are substituted for A and 'A in the foregoing description of the operation of the apparatus shown in Figs. 1 and 2.

gentially to A and A, thereby causing the gas currents to follow a spiral path, and in the apparatusshown'in Figs. 3, 4 and 5, by

delivering the gases to the centers of A and A, and providing a series of hoods m over the delivery openings in B and B, whereby the gases are deflected into annular rings thus distributing them over the hori zontal sections of A and A.

Valves 0 and 0 may be operated by 'an electric motor or other'suitable equipment,

furnished with a device by which the intervals at which these valves areoperated may be controlled. Fig. 6' illustrates one form of apparatus for operating valves 0 and 0,

in which the lever f is equipped with an arm 11,10 and o are electromagnets located on opposite sides of arm n; the electromagnetis- 0 and o. are alternately magnetized by elec tric current, the alternating period being controlled by a suitable clock device. If 0 is magnetized, valve 0 is closed and valve 0 opened by the arm n being drawn into magnetic contact with 0 and likewise, when 0 is magnetized valve 0 is closed and'valve 0 opened, by the arm n being drawn into magnetic contact with 0.

In the previously described form of apparatus the gases enter near the bottoms of s A and A; Figs. 7, 8 and 9 illustrate a form 1 of apparatus wherein the gases enter at the tops of A and A, and are dischargednear the bottoms thereof. The operation of this .form of apparatus will be readilyunderstood from the previous description of the operationof the apparatus shown in Figs. 1 and 2, it being borne in mind that the gases enter the receptacles A and A through B and B respectively, and are discharged from A and A through p and p to C; [It is to be noted that instead of valves 0 and c in A and A of Figs. 1 and 2, there is shown in Fig. 9 a flap valve 9 pivoted at r by means of which the flow of gases from A and A maybe controlled; as shown in Fig. 9, the valve 9' is in such position that the gas will flow from A, while if the valveiis thrown to the position indieated'by dotted line 8, the gas will flow from A A hood 1) is rovlded over the inlets to B and B to prove t solidsdeposited in A or A from entering-p or p. It is alsoto be noted that if it is found desirable to provide control valves in both .the gas inlets and outlets to and A, a flap valve t hinged at u (see Fig. 8) may be inserted Where branches B and B" are connected to the gas supply pipe D; as the valve t isshown in Fig. 8, the gases will enter A, whereas if the valve is thrown to the position indicated by the gases will flow to, It is evident that if desired, a valve similar to 1' can be utilized to control the flow of gases to A and A in the forms of apparatus shown'in Figs. 1 and 2 and in Figs. 3, 4 and 5.

- Valves 9 and t may be operated by electric motors or other suitable equipments, furnished with devices by= which the intervals at which these valves are operated may be controlled. Fig. 10 illustrates one form of Fi .e.- inother form of apparatus is illustrated in Figs. 11 and 12 in which a series of three receptacles A, A and A are provided, equipped at their tops respectively with valves 0, 0 and 0", and at their bottoms with branch pipes B, B and B leading from the gas supply pipe D. .Valves 0, 0

and 0 are suspended by rods e from levers f pivoted at g, the weight of the valve being partially counterweighted by 2 in each case, in such manner that said valves remain open unless force is exerted to lift and close them. One method of operating and controlling valves 0,- c and 0 is to provide respectively for each valve electromagnet 0, o and 0 which, when magnetized by electric current, draw the counterweights 2 in contact with said magnets thereby closing the valves; the electric current supply to the magnets being controlled by a suitable clock device. In the operation of the apparatus shown in Figs. 11 and 12, the gases admitted by B and B or B respectively, are brought to rest in A, A or A, in such manner that the gases are at rest in two receptacles during the'interval that the gases, from which the solids have been removed, are bein forced out of the third receptacle by the ad mission of gases from which the" solids have not been removed. It is evident that under this-method of operation, the gases will be at rest for twice the interval of time that is required to force the gases, from which the .,solids have been 'remo'ved, out of one receptacle. By providing a suitable clock device to control-thesupply of electric current to the electromagnets 0,v 0 and 0", it is obvious that valves 0, 0" and 0- may be operated and closed at and for the intervalsthe dotted line w,

that it is desired to bring the gases to rest in receptacles A, .A, A. It is obvious that the number of receptacles in the apparatus shown in Figs. 11 and 12 may be increased to any desired number.

It is evident that, whereas in the forms of apparatus shown in the variousfigures valves are provided in the gas outlets from receptacles A, A and A, it is quite possible to dispense with these Valves and provide valves only in the gas inlets to said receptacles, or valves may be provided in both the gas inlets and outlets to and from said receptacles; it

is essential however that valves be provided either in the gas inlets or outlets.

In the forms of apparatus previously described, one means of removing the solids deposited in the receptacles is shown namely, through the counter-weighted valves i located at the bottoms of said receptacles and operated by lifting the counterweight is; it is evident that any suitable valve may be used instead of valve 2'.

In the event of the height of the receptacles and the character of the solids being such, that the interval of time during which the gases are at rest, is not suflicient for the solids to fall through the height of the receptacles and be deposited in the bottoms thereof, the distance through which a portion of the solids fall may be reduced as indicated in Figs. 13 and 14. Fig. 13 shows a section of one receptacle A, similar to that shown in Figs. 1 and 11, in which is inserted a conical hopper 4: of less diameter than the interior of A, a pipe 5 leading from said hopper to the bottom of the receptacle A and a conical hopper 6 located above hopper 4. With these devices it is evident that solids carried by the gases above hoppers 4 and 6 which, during the interval the gases are at rest, are deposited in hopper 4, are conducted by pipe 5 to the bottom of A, without being brought in' contact with gases which may enter through B, and that the distance through which the solids must fall, both above and below hopper 4, in order to be removed from contact with gases entering at B is reduced. To secure a similar result in the receptacles shown in Figs. 3 and 7, cylinders 7 (see Fig. 14) of a less diameter than the interior of A, and having open conical top and bottom and equipped with hood 8, located above the opening in the top of 7, may be inserted in A, it being evident that solids falling on the hood 8 and the conical top of 7 will be conducted to the bottom of A, without coming in contact with the gases. which may enter through B.

The bottom of 5 of Fig. 13 and the bottom of 7 of Fig. 14 are located so as to be almost but not quite, in contact with valves 2', by which means in connection with solids deposited in the bottom of A, a sufficient seal is provided to prevent gases entering at B- from passing into the bottom of 5 or the;bottom ofthe annular space around 7. It is evident that pipe 5 Fig. 13 may be so installed as to lead the deposited solids to a sealed chamber outside of A, from which chamber the solids may be removed in any approved manner.

Devices 4, 5 and 6 of Fig. 13 and 7 and 8 of Fig-let may be supported in any approved manner.

It is evident devices of other designs can be installed in A to secure the foregoing described result.

It is evident that, while the hereinbefore described apparatus embodies a dry system of cleaning gases, the same principle of removing solids while the gases are at rest, can be applied to a wet system of cleaning gases by inserting water sprays in A, A and A, and further, that the same principle of removing solids while the gases are at rest can be applied to the electrical method of cleaning gases by inserting the necessary electrical equipment in A, A and A.

It is obviousgthat the novel and essential feature of my invention lies in the fact the gases are brought to a state of rest during the period that the solids suspended in or carried by the gases are removed therefrom, without interrupting the flow of the gases from their sources of generation or supply and without limiting the quantity, and flow of said gases to their points of utilization.

I interpret the words removing solids suspended in or carried by gases as they occur in the claim, to mean the separation of such portion or quantity of said solids from said gases as may be desired and the prevention of the solids so separated from again becoming suspended in or carried by said gases.

I claim s The method of purifying gases by removing solids suspended in or carried by gases, which consists in directing the current of gases into one or more receptacles for an interval of time, thereafter directing the current of gases into other purifying means for a period of time sufficient to permit the desired portion of the solids to be removed from the gases in said one or more receptacles, and thereafter re-directing the-current of gases into said one or more receptacles to displace the purified ases.

Signed at hiladelphia, Pennsylvania, this 21st day of January, 1921.

FRANK o. ROBERTS.

Witnesses: R. H. MILLER,

WM. PAXToN ROBERTS.

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