US3377058A

US3377058A - Cupola furnace installations having a safety bypass

Info

Publication number: US3377058A
Application number: US488901A
Authority: US
Inventors: Panzica Nicholas John
Original assignee: Ajem Laboratories Inc
Current assignee: Ajem Laboratories Inc
Priority date: 1965-09-21
Filing date: 1965-09-21
Publication date: 1968-04-09
Anticipated expiration: 1985-04-09
Also published as: BE687200A; DE1508554A1; CH454364A; GB1160119A

Description

April "1968 N. J. PANZICA 3,377,058

CUPOLA FURNACE INSTALLATIONS HAVING A SAFETY BYPASS .Filed Sept. 21, 1965 "lmlllmh INVENTOR NICHOLAS JOHN PANZICA BY M, m; r

- ATTORN EYS United States Patent 3,377,058 CUPOLA FURNACE INSTALLATIONS HAVING A SAFETY BYPASS Nicholas John Panzica, Detroit, Mich, assignor to Ajem v Laboratories, Inc., Livonia, Mich.

Filed Sept. 21, 1965, Ser. No. 488,901 Claims. (Cl. 266-) ABSTRACT OF THE DISCLOSURE A safety bypass for air pollution control equipment for cupola furnaces including a fan between the downcomer from the cupola furnace and the air washer, which fan is operative to exhaust the quenched, cooled, partially scrubbed fumes from the downcomer directly to the atmosphere when the air washer is inoperative.

The present invention relates, in general, to cupola furnace installations and more particularly to such an installation having a bypass which permits continuous and uninterrupted operation of the cupola furnace.

In operation, a cupola furnace emits a wide variety of pollutants such as solid particulate matter, hot gases, toxic and deadly fumes, and incendiary particles to the surrounding environment when the cupola cap is open. The cupola cap is opened to prevent the buildupof gases in the furnace and backfires at the charge door. The burning particles emitted from the furnace can, when exhausted to the atmosphere, cause seriousinjuries to personnel in the area or may cause fires on structures on which these particles settle. The other less dangerous pollutants, while not creating a hazard, do produce an exceedingly objectionable nuisance.

Various attempts have been made to solve the probems caused 'by'the emissions from cupola furnaces. These attempts have been generally directed toward overcoming the hazards created by the emissions of the burning ,particles. One such endeavor has been to increase the height of the furnace and sometimes increase the inside diameter of the top section of the furnace. This solution has not proven satisfactory since the same materials continue to escape with only a slight reduction in the temperature of the polluted air and its contents.

Another attempt has involved the placement of a spray bafile chamber on the top of the cupola furnace. The

intent here has been to cool the gases, quenching the incendiary particles and dropping the temperature of the mixture, while at the same time removing some of the solid airborne particulate matter. It has been found that such a spray chamber fails to perform the desired functions. Even with such a spray chamber at the top of the furnace, the emitted gases have been found to be quite hot in the order of 700 to 800 F. In addition, a considerable amount of solid particulaternatter and incendiary combustible materials continue to escape.

Another approach taken in attempting to solve the problem of the emissions from the cupola furnace has involved the use of wet caps installed at the top of the furnace. In such an installation, liquid is pumped through a water inlet and emptied on top of a distributor cone located at the top of the furnace. A drain trough is located at the bottom of the cone and receives the liquid as it drains off of the cone. The trough prevents the water from dropping down into the furnace. This structure creates a cylindrical water droplet curtain extending from 3,377,058 Patented Apr. 9, 1968 the bottom of the distributor cone to the drain trough. The emissions from the cupola furnace pass up through the water curtain and out to the atmosphere. The emissions passing through the water curtain are to a limited extent cooled and some of the solid particulate matter is captured by the water and collected in the drain trough. The drain trough is arranged to be lower at one point so as to develop a flow of the liquid through a drain pipe to a reservoir.

There are a number of shortcomings and limitations in the use of wet caps in capturing and cooling the pollutants emitted from the cupola furnace. One such shortcoming is that wet caps do not operate efiiciently in removing the solid particulate matter to the extent required by various Naional, State and Municipal codes. Second, while the wet cap does reduce the temperature of the emissions to some extent, which is still far from that required by the various codes, flames and incendiary particles continue to escape so that the hazards of fi re to the adjacent environment are still present. A third shortcoming of a wet cap installation is that great quantities of liquid are required to flow over the distributor cone. It has been found that the results achieved in the removal and cooling of pollutants do not justify the effort involved in furnishing such great quantities of liquid. Another shortcoming involved in the use of wet caps is that the components of the wet cap are susceptible to rapid rusting and degradation, thus requiring continuous servicing and replacement. In the event of a water failure, the distributor cone is subject to destruction dependent upon the extent of exposure to the'heat of the cupola furnace. If a component such as the distributor cone rusts through completely or becomes damaged, water may drop into the cupola furnace causing serious damage from-explosions Which are due to the formation of hydrogen and oxygen and the subsequent reuniting of the oxygen and the hydrogen.

An arrangement for solving the problem of emissions from a cupola furnace which has met with success makes use of a downcomer followed by an air Washer. A downcomer is a vertical structure of substantially the same height as the cupola furnace which is positioned alongside of the furnace. Just below the top of the cupola-furname is a cross-over passage through which the pollutants pass from the furnace to the downcomer. The downcomer serves to capture a large portion of the pollutants and particularly the large particulate matter. The lighter particulate matter is captured by the air washer which is connected to the downcomer outlet by a duct system. The downcomer is provided with a number of different spray arrangements. These sprays are effective in cooling the hot gases emitted from the furnace and quenching flames and incendiary particles. It is important to cool the hot gases in order to bring the temperature of the gases to the maximum allowable for entry into the particular air washer.

Although a cupola furnace installation employing a downcomer and an air washer has proven effective in should continue to operate and not be shut down. The I present practice under such conditions is to open the dry capat the top of the cupola furnace. This results in the pollutants spreading over the surrounding neighborhood causing the same hazards previously considered.

It is an object of the present invention to provide a new and improved cupola furnace installation.

It is another object of the present invention to provide a cupola furnace installation having equipment which efficiently captures particulate matter and other undesirable emissions from the furnace.

It is a further object of the present invention to provide a cupola furnace installation having equipment for removing pollutants emitted from the furnace which is not subject to limitations and shortcomings of comparable equipment presently being used for the same purpose.

It is a still further object of the present invention to provide a cupola furnace installation having equipment which permits continuous and uninterrupted operation of the furnace.

A cupola furnace installation constructed in accordance with the present invention and described hereinafter includes a cupola furnace and a downcomer communicating with the cupola furnace for receiving pollutants from the furnace and for capturing a portion of these pollutants. Also included in this installation are an air washer communicating with the downcomer for receiving and capturing that portion of the pollutants not captured by the downcomer and a fan adapted to be inserted between the downcomer and the air washer to exhaust the pollutants not captured by the downcomer when the air washer is inoperative.

In the specification and in the accompanying drawings, there is described and shown an illustrative embodiment of the invention and various modifications thereof are suggested. It is to be understood that these are not intended to be exhaustive, but on the contrary are given for purposes of illustration in order that others skilled in the art may fully understand the invention so that they may modify and adapt it in various forms, each as may be best suited to the conditions of a particular use.

The various objects, aspects and advantages of the present invention will be more fully understood from a consideration of the following specification in conjunction with the accompanying drawing in which there is shown a cupola furnace installation constructed in accordance with the present invention.

The cupola furnace installation shown in the drawing includes a cupola furnace of standard construction and operation. Cupola furnace 10 is disposed vertically in the usual manner and is charged through charging door 10a.

Alongside cupola furnace 10 and also disposed vertically is a downcomer 11. Downcomer 11 may also be of conventional construction and operation. The downcomer 11 communicates with the cupola furnace 10 through a crossover 12 which extends from the top of the furnace 10 to the top of the downcomer 11. The crossover 12 serves to pass the pollutants from the cupola furnace to the downcomer.

The downcomer 11 serves to capture a portion of the pollutants emitted from the furnace 10. This is achieved by some of the pollutants freely falling into the conical portion 13 at the bottom of the downcomer and others being captured by the sprays within the downcomer. Since the downcomer 11 and the spray apparatus within the downcomer may be of conventional construction the details of the internal structure have not been shown. The freely falling pollutants and the pollutant laden spray droplets are flushed out of the conical portion 13 through a pipe 14 to a tank 15. Tank 15 may be a sedimenting tank or a recirculation tank where water is held for reuse in the spray systems in the downcomer. The spray systems receive the required quantities of Water by means of a pair of pumps 18 and 19 which pump clean water from the tank 15 through a pair of valves 16 and 17 to the spray systems.

The downcomer 11 is effective in removing a large portion of the pollutants and, in particular, the larger particulate matter. Besides removing a portion of the pollutants, the downcomer 11 cools the hot gases emitted from the furnace. The resulting reduction in temperature of these gases permits passing these gases to an air washer for capturing that portion of the pollutants not captured by the downcomer.

A duct 20 communicates with the downcomer 11 at the lower end of the downcomer. The duct 20 leads to an air washer 21 of conventional construction and operation. A duct 22 leads from the air washer to a moisture eliminator section 23. A fan 24 serves to develop the proper draft for drawing the pollutants from the cupola furnace 10 through the cross-over 12 into the downcomer 11 and out through the duct 20 to the air washer 21 and the moisture eliminator section 23. The air washer 21 re ceives that portion of the pollutants not captured by the downcomer 11 and operates in the usual manner in cap turing these pollutants so that cleaned air is exhausted through a stack 25 to the atmosphere. Since the downcomer 11 is effective in capturing the larger particulate matter, the air washer is left with a lighter load.

If the air washer for some reason malfunctions or some switching mechanism causes the air washer to be shut down, an auxiliary fan 26, adapted to communicate with the duct 20 at a point between the downcomer 11 and the air washer 21, maintains the proper draft through the installation and receives the pollutants not captured by the downcomer. These pollutants are, in turn, exhausted through a stack 27. This diversion of the pollutants from the downcomer 11 is achieved by means of a damper 28 which may occupy the two positions shown dotted in the duct 20. In particular, with the air washer 21 operating in the normal manner, the damper 28 is so positioned as to form a portion of the wall of the duct 20 and to close off the auxiliary fan 26 from the duct 20 causing the pollutants to follow their normal path to the air washer. If, however, the air Washer is rendered inoperative, the damper 28 occupies a second position in which it extends across the duct 20 so that the air washer is closed off and the pollutants are directed to the auxiliary fan 26. When the air washer 21 is again rertdered operative, the damper 28 is moved back to the first position so that the apparatus may resume functioning in the usual manner. The damper 28 may be moved manually, for example, by a handle when the air washer 21 becomes inoperative or resumes normal operation. Alternatively, the damper may be moved automatically by an electro-mechanical drive responding to one or more tie tectors which sense a failure in the air washer or excessively high gas temperature.

Although pollutants are exhausted to the atmosphere by the auxiliary fan 26, the quantity of the exhausted pollutants is considerably less than the pollutants exhausted through dry caps or escaping through wet caps. This result is due to the downcomer 11 functioning continuously and removing the greater portion of the pollutants. In addition, an installation according to the present invention emits gases at far lower temperatures and prevents fiames and incendiary particles from leaving the exhaust stacks both while the air washer is operative and inoperative.

While there has been described what is at present considered to be the preferred embodiment of this invention it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. A furnace installation comprising:

a furnace;

a downcomer communicating with said furnace for quenching flames and incendiary particles, cooling an air washer communicating with said down-comer for receiving and capturing that portion of said pollutants not captured by said downcomer;

and a fan inserted between said downcomer and said air washer and operative to exhaust the efliuent from said downcomer, including said pollutants not captured by said downcomer, when said air washer is inoperative.

2. A cupola furnace installation comprising:

a cupola furnace;

a downcomer communicating with said cupola furnace for receiving pollutants from said furnace and for quenching flames and incendiary particles, cooling gases, and capturing a portion of said pollutants;

an air washer for receiving and capturing that portion of said pollutants not captured by said downcomer;

a duct extending between said downcomer and said air washer for passing said pollutants not captured by said downcomer to said air washer;

and an auxiliary fan in communication with said duct at a point between said downcomer and said air washer; and operative for drawing said pollutants from said cupola furnace into said downcomer and for exhausting said pollutants not captured by said downcomer when said air washer is inoperative.

3. A cupola furnace installation comprising:

a cupola furnace;

an auxiliary fan in communication with said duct at a point between said downcomer and said air washer and operative when said air washer is inoperative for drawing said pollutants from said cupola furnace into said downcomer and for exhausting said pollutants not captured by said downcomer;

and a damper positioned in said duct for directing said pollutants to said auxiliary fan when said air washer is inoperative.

4. A cupola furnace installation according to claim 3 wherein the damper occupies a first position when the air washer is operative in which the auxiliary fan is closed off from receiving pollutants and a second position when the air washer is inoperative in which the air washer is closed off from receiving pollutants.

5. A cupola furnace installation comprising:

a cupola furnace;

a downcomer for receiving pollutants from said furnace and for quenching flames and incendiary particles, cooling hot gases, and capturing a portion of said pollutants;

a cross-over passage extending between said cupola furnace and said downcomer for passing said pollutants from said furnace to said downcomer;

an air washer communicating with said downcomer for receiving and capturing that portion of said pollutants not captured by said downcomer;

and an auxiliary fan inserted between said downcomer and said air washer and operative to exhaust the effluent from said downcomer, including said pollutants not captured by said downcomer, when said air washer is inoperative.

6. A cupola furnace installation according to claim 5 wherein the cupola furnace and the downcomer are disposed vertically and the cross-over extends from the top of the furnace to the top of the downcomer.

7. A cupola furnace installation according to claim 3 wherein the duct communicates with the downcomer at the lower end of the downcomer.

8. A cupola furnace installation comprising:

a cupola furnace;

and an auxiliary fan in communication with said duct at a point between said downcomer and said air washer; and operative for drawing said pollutants from said cupola furnace into said downcomer and for exhausting said pollutants not captured by said downcomer when said .air washer is inoperative.

9. A cupola furnace installation comprising:

a cupola furnace;

a duct extending between said downcomer and said air washer for passing said pollutants not captured by said downcomer to said .air washer;

and a damper positioned in said duct for closing off said auxiliary fan from said duct when said air washer is operative and for closing off said air washer and directing said pollutants to said auxiliary fan when said air washer is inoperative.

10. A cupola furnace installation comprising:

a cupola furnace disposed vertically;

a down-comer disposed vertically for receiving pollutants from said furnace and for quenching flames and incendiary particles, cooling hot gases, and capturing a portion of said pollutants;

a cross-over passage extending from the top of said cupola furnace to the top of said downcomer for passing said pollutants from said furnace to said downcomer;

a duct extending from the lower end of said downcomer to said air Washer for passing said pollutants not captured by said downcomer to said air washer;

and a damper positioned in said duct for closing off said auxiliary fan from said duct when said airwasher 7 8 is operative and for closing olf said air washer and 2,208,443 7/1940 Ashley 55312 directing said pollutants to said auxiliary fan when 2,723,842 11/1955 Hall 266-15 said air Washer is inoperative. 3,173,980 3/ 1965 Hysinger 26615 References Cited 5 FOREIGN PATENTS UNITED STATES PATENTS r 426,463 5/1911 France. 1,171,696 2/1916 Brassert et a1. 266-15 Mach:e J. Prlmary Examiner. 1,497,727 6/ 1924 Klugh 266-16 R, S. ANNEAR, Assistant Examiner. 2,058,919 10/1936 Sewell. 10

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,377 ,058 April 9 1968 Nicholas John Panzica It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shmm below:

Column 4, line 74, beginning with "a downcomer cancel all to and including "pollutants;" in cOlumn'Sy-lin'e, 2, and insert a downcomer communicating withsaid'furn'ace for receiving pollutants from said furnace and for quenching flames and incendiary particles, cooling gases, and capturing a portion of said pollutants Signed and sealed this 16th day of September 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer