US2538057A - Method of cleaning circulating heaters - Google Patents

Description

Jan. 16, 1951 w. c. STEELE METHOD OF CLEANING CIRCULATING HEATERS 2 Sheets-Sheet 1 Filed Dec. 6, 1945 4 I n A 1 '44 z INVENTOR W/LL/ C JfffLE BY d ATTORNEY W. C- STEELE METHOD OF CLEANING CIRCULATING HEATERS Jan. 16, 1951 2 Sheets-Sheet 2 Filed Dec. 6, 1943 INVENTOR Patented Jan. 16, 1951 UNITED STATES PATENT OFFICE METHOD OF CLEANING CIRCULATING HEATERS William C. Steele, Seattle, Wash.

Application December 6, 1943, Serial No. 513,156

3 Claims. 1

This invention relates to the internal cleaning of oil burning heaters and furnaces having certain characteristics of construction including an open top pot in which the fuel oil is burned. More particularly, the invention relates to methods for the burning off and removal of the carbon crust or deposit that forms on the side and bottom walls of the burner pot incident to its use over an extended period of time.

For better understanding of the present invention and its objects, it will here be explained that during the last decade, a certain type of oil burning heater has gone quite extensively into use for residence, hall and store heating as well as for other purposes. The burner unit, in such heaters, includes a burner pot, with a basin in its bottom into which the fuel oil is permitted to flow under automatic control and in which the admitted oil is burned. The side walls of this pot are formed with a multiplicity of small perforations, or ports, through which fresh air is admitted to the interior of the pot from a chamber surrounding it to facilitate the combustion of gases that are produced by the burning oil. The top of the pot is open and it communicates directly with a combustion chamber of substantial size. Surrounding the combustion chamber is a hot air drum through which air is circulated for heating and from which the heated air passes directly or indirectly to the area that is to be heated. It is common practise to employ a fan blower in connection with a, duct system to expedite the circulation of heating air. However, it is possible to heat rooms by natural circulation created merely by the heating of the air.

Other designs of heaters, using the same type of pot burner, are now on the market and are being put to various uses; for example, for water heating and for cooking. The designs and shapes of the burner pots may vary considerably as may also the control and manner of feeding fuel oil thereto, but it is always the case that the burner pot walls that confine the burning oil are formed with perforations for the admittance of air into the pot to facilitate combustion. When these walls and the perforations therein become covered or clogged with carbon, the heating operation is greatly impaired if not entirely prevented for obvious reasons.

To obtain the best results and the greatest heating efflciency in the use of burners of this general character, it is required that the inside surfaces of the pot walls be kept clean and free of carbon, especially if such carbon covers or partially fills up the air inlet perforations. How- I ever, due to the character of construction of such pots and furthermore, due to their particular position of installation or location within the heater housing, it has, in the past, been a very diflicult task to obtain access thereto to clean the walls and to remove the carbon. Such cleaning of the pot usually is done by scraping the walls and then scooping out the scale that falls to the bottom of the pot as it is scraped off.

In view of the very detrimental effects of this carbon coating of the burner pot walls in the use of such burners or furnaces and the difficulties heretofore experienced in cleaning or decarbonizing such burners, it has been the prin-- cipal object of this invention to provide a novel, simple, expeditious method for cleaning the interior of the burner pot and for opening up the pot wall perforations.

More specifically stated, the objects of this invention reside in the improved methods of cleaning pot burners of collected carbon by producing fire in the burner pot, then intensifying the flame and heat therefrom, and finally effecting a concentration of the. heat and flame for carbon burning against selected surface areas by the directional application of one or more air streams.

Other objects of the invention reside in the various steps of the present method and in the sequence of steps in practising the method.

In carrying out the present method, I employ apparatus which has been illustrated in the accompanying drawings, wherein:

Fig. 1 is a vertical sectional view of an oil burning heater, illustrating the application of burner cleaning apparatus for burning out the carbon from the burner pot in accordance with the present method.

Fig. 2 is a horizontal section of the same parts, taken on line 2-2 in Fig. 1.

Fig. 3 is an enlarged, vertical sectional view of the burner pot, illustrating the feeding of oil and the application of air, and showing also the action of the suction applied to the air chamber that surrounds the burner pot.

Fig. 4 is a perspective view of parts of an alternative type of pot cleaning equipment.

Fig. 5 is a view illustrating means for reversing the direction of air through the suction tube.

Referring more in detail to the drawings:

In Figs. 1 and 2, I have illustrated a burner that is typical of that kind for which the present cleaning equipment is intended for use. The humor, as herein shown, comprises an outside, air-tight housing II) that encloses the housing l2 forming the combustion chamber [3. Within the base of the housing 12 is a burner pct 14 formed with a top opening [5 that is in direct communication with the chamber l3. Between the walls of the burner pot and the outer housing I0 is an air chamber l6 that is closed off from the combustion chamber by the annular partition plate I! that is applied against the upper end flange of the pot. Fresh air is admitted into the chamber Hi. This may be through an opening in the housing ID, as that at I8 in Fig. 1, or through a suitable opening in the bottom wall of the housing, or it might be supplied, as has been shown in Fig. '1, through a pipe 19 that is extended into the chamber 16 from a fan blower. Such a pipe l9 would be equipped with a damper, as at 19c, so that admission of air through this connection could be cut off.

In Figs. 1 and 2, I have indicated a fan housing at 20, in which a fan blower, not shown, of any suitable kind might be located to furnish air under pressure through the pipe connection l9 to the chamber [6 and also through a relatively large pipe 2| into the housing It).

'At its top, the housing H] has an outlet 25 which, as shown, opens into an air duct system 25a as shown, or, in some uses of the burner, might open directly into the area to be heated. A stack connection 26 leads from the chamber l3 and this provides for escape of gases of combustion from the chamber. At the front of the combustion chamber is an opening 21 which would be equipped with a door of a suitable character.

In Fig. 3, I have shown an enlarged cross sectional view of the burner pot. However, it is understood that this design of pot used might be varied considerably without requiring change in the construction of the cleaning equipment or its mode of use. The particular type of burner pot shown has a peripheral, inturned flange 30 about its upper end opening, and it has an inwardly directed flange 3| spaced somewhat from the top opening. The side walls of the pot are vertical and are provided with a multiplicity of perforations or ports 35 for the admittance of air to the interior of the pot to facilitate the burning of oil therein. It is here shown that provision is made for supplying fuel oil to the pot through a small .pipe 36 that leads from an automatic float controlled regulating device which is indicated generally at 31.

The normal method of starting this type of burner requires that a certain amount of fuel oil be admitted to the burner pot through the pipe 36. This is ignited and after the pot has become heated up by the burning oil and a draft is created, the flow is permitted to continue. The burning oil creates an updraft and the gases of combustion are carried out of the pot and burn within the combustion chamber.

In view of the fact that combustion is incomplete within the pot, operation over a period of time causes a scale of carbon to be formed on the pot walls and this scale will ultimately fill, or partially fill, the perforations, thereby cutting off the supply of fresh air thus further aggravating the condition caused by the carbon on the walls. Also, it has been found that a very thick deposit of carbon will be formed on the bottom wall of the burner pot about the spot where the fuel oil enters, and this deposit finally interferes with the spread or distribution of oil. and causes burning to take place in spots rather,

4 than to be spread entirely over the bottom wall. This results in additional difficulty.

The present portable cleaning apparatus, in its simplest form, comprises a small wheel equipped truck, or other type of easily portable vehicle, upon which two blowers 5| and 52 are mounted. These blowers are herein illustrated as being fan equipped suction blowers, and operatively driven by an electric motor 53 connected to the blower shaft 54, which is common to both, by a belt 55 operating over suitable pulleys 56 and 57 on the motor shaft and fan shaft, respectively.

To the suction side of the blower housing 5|, a flexible air tube 60 is attached, and from the delivery o pressure side of the blower housing 5|, a tube 6! is extended. This may lead a considerable distance as is sometimes required in order that its discharge end will be outside of the building in which the burner being cleaned is located. Preferably this pipe 6! is made up of short jointed sections so that it can be handled. easily and directed around corners or through doorways as required to reach the outside of the house.

To the discharge or pressure side of the blower 52, a flexible hose is attached, and at its end, this has a fitting 66 with two separate outlets to which two small flexible metallic pipes or tubes 67 and 68 are attached. These pipes are in the nature of air nozzles and may be extended through the opening to the combustion chamber and into the burner pot as shown in Fig. 1.

It is anticipated, but not herein shown, that flexible rubber tubes might be used between the fitting 66 and the nozzles 6! and 68 to make them more easily positioned and more easily controlled individually.

The two pipes would preferably be of an easily bendable metal, such as copper, so that they might be bent as required for directing air therefrom to any particular part of a burner pot regardless of its special design. The separate outlets of the fitting 66 are equipped with individual valves 69 and Ill for control of the delivery of air through the nozzles; it being understood that with the blower 52 in operation, air will be delivered under pressure to the pipe 65 and from this to the nozzles 61 and 68.

In the use of the device as it has been shown in'Figs. 1 and 2, for cleaning the burner pot, the flexible suction tube 60 is first extended into the air chamber 16 that surrounds the burner pot by passing it through a housing opening l8. Then the space around the tube and edge of the opening is plugged with a rag or the like, so that effective suction or partial vacuum may be created within this chamber l6 when the blower 5| is in operation.

Preparatory to cleaning the pot, a small quantity of fuel oil is allowed to flow into the bottom wall. If such a supply of oil cannot be furnished through the burner supply line 36 with which the burner is equipped, then an auxiliary supply device such as the small container 13, shown in Fig. 1, is used. From this container, a flexible metallic pipe 74 extends downwardly and may be passed through the front opening of the burner housing and lead into the pot to near the bottom wall thereof as shown best in Fig. 3. A valve, as at 16, in discharge pipe 14 leading from the bottom of container 13, may be adjusted to regulate the flow of oil through this line. After a quantity of oil has been admitted to the pot in this way, it is ignited. Then the fan blowers are set in operation and the nozzles 61 and 68 are extended into the pot as shown in Fig. 1. Then,

by opening the valve 69 air is admitted through pipe 6'! to cause fuel combustion to take place within the burner pot rather than permitting the unburned gases to rise into the combustion chamber. The flame is greatly increased and heat is intensified quite naturally in the burner pot, and the pot quickly becomes very hot.

It will be understood that by supplying an adequate amount of air to the inside of the pot in this way, while applying suction t the chamber surrounding the pot, flame in considerable amount is created, and part of it will be drawn through the perforations of the pot walls due to suction created in chamber 18. Thiscauses the carbon in the perforations to burn. While air is thus being supplied in adequate amount through the pipe 6'! to create considerable flame inside the pot, valve 10 is opened and the nozzle 68 is held at a position to direct a stream of air therefrom into the flame and toward any selected area of the pot walls where the carbon deposit is heavy and seems to cling, so as to'concentrate the flame on that area and thus cause the carbon to be ignited and more quickly burned away. While it is burning, the scale peels off or is blown oft and falls into the bottom of the chamber.

The use of this nozzle 68 is particularly advantageous for directing the flame into angles or corners where it would otherwise be difiicult to cause the flame to contact. Thus the carbon can be burned away in the corners by proper directing of the air streams.

The height of flame in the pot may be governed by the location of the outlet of the pipe 61. By placing it close to the bottom wall, the flame will be lifted up toward the top. By raising it to near the top entrance, the flame will be made to spread out against the side walls of the pot. By blowing the air stream tangentially against the pot wall, a whirling mass or wall of flame will be caused to follow around the pot walls and this may be raised or lowered with lowering or raising of the tube outlet. Thus, most any condition of flame desired may be obtained by the selected directional application of the air streams. A whirling mass of flame in the pot creates suction inwardly through the pot perforations and with vacuum removed from outside the pot walls, this facilitates the burning of carbon in the perforations and about them inside of the pot.

It is anticipated further in the use of the device of Figs. 1 and 2, that an oil pump, as indicated at in Fig. 2, might be installed within the truck or portable vehicle to be driven also by motor 53, and this pump would be equipped at its suction side with a pipe connection 86 leading into a supply container 81. From the other side of the pump, a delivery tube 9t, corresponding to the supply tube 14, would be extended to the interior of the pot. A suitable valve would be applied in the pipe connection 85 to control the amount of oil supplied to the pot in this manner. Furthermore, the suction line 86 might have an extension, as indicated at 86a, for the withdrawal of fuel oil from the regulator device 3'! when it is desired that it be cleaned or for other uses.

In the alternative form of device illustrated in Fig. 4, it is anticipated that a flexible air supply tube 94, somewhat larger than pipe 65, be extended from the blower 52, and that this connects to a pipe 95, curved to afiord its application into the burner, and which at, its end, is equipped with a plurality of radiating air discharge nozzles 95. The nozzles are curved at their ends so that when placed inside the burner 6 I put and the air turned on, a whirling blast be createdin the pot that expedltes the operation of burning off the carbon. Oil is here supplied through a pipe line 90 that leads from the pump through the pipe 94 and into the pipe 95 as shown.

In this arrangement of pipe line 90, it terminates within pipe 9'5, and at its end isequipped with an atomizing nozzle 9|. oil is supplied into the air stream and ignites on discharge from the nozzle 96 causing jets of flame to be blown against the walls. Auxiliary air for facilitating complete burning is here supplied through a pipe 610: that leads off from pipe 94. Air from this pipe may be used also to concentrate the flame at a desired position on the burner pot walls.

After burning has been completed, then the ash and scale that has dropped into the bottom of the pot may be sucked out by applying the suction hose to the interior of the pot by passing it intothe pot through the housing opening 2? and top opening of the pot.

" In Fig. 5, I have illustrated a pipe arrangement which is anticipated where it is desired that means he provided for reversing the direction of air through the suction tube 60. Explanatory to this, it might be said that in the use of the cleaning apparatus, it sometimes happens that the pot becomes extremely hot due to the fact that combustion of oil takes place therein which is greatly augmented by the supplying of air through the tubes 61 and 68. Therefore, it has been found practical toprovide means whereby the direction of air can be reversed through the tube 60 for the purpose of cooling oil the overheated bowl. In Fig. 5, I have shown a pipe connection H0 between the suction and delivery sides of the blower 5!. At opposite ends of this pipe connection are dampers H2 and H3, which may be positioned to close the ends of the pipe H0 and normal use of the suction pipe 60, or to be moved to their opposite positions. In the suction connection of the blower is an auxiliary air inlet H5 equipped with a damper or closure device H6. If it is desired to reverse the direction of air through the tube 60, the dampers are set in the position as illustrated in Fig. 5, thereby causing outside air to be drawn into the blower through the opening H5 to be delivered through the pipe I ll] back into the tube 60. This air will be blown into the chamber I6 and being cool air, will effect the cooling of the burner pot.

Devices of this kind greatly lessen the task of cleaning burner pots, and makes it possible to thoroughly and completely remove the carbon scale from the pot walls and also from within the pot wall perforations. It is understood that various modifications are possible without departing from the spirit of the invention, and therefore it is not desired that the claims shall be limited to details, but shall be considered commensurate with the invention that has been disclosed.

In this connection it will be explained that insofar as burning the carbon free of the pot walls is concerned, it may be accomplished without suction being applied to the chamber that surrounds the pot. However, this is desirable as it facilitates burning out the material in the perforations and aids in the operation by taking out the fumes and gases through the suction pipe and not allowing them to flow out of the open combustion chamber into the room.

When suction is not employed, flame control and direction are maintained through a direc- Thus, atomized tional application of air streams from the tubes 61 and 68. Fire may be maintained for this op eration by oil that is fed from the regular supply, or oil from the supply tank l3. Further more, fire may be supplied by other auxiliary means such as from a gas flame, and its intensity could be increased by auxiliary air as previously explained.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is:

1. The method of decarbonizing a pot burner of the character described comprising causing oil to burn on the bottom of the pot, directing a jet of air under pressure into the pot in a tangental direction to cause the flames to move in a whirling blast about the pot walls, and simultaneous ly directing another jet of air under pressure through the whirling mass of flame toward a selected area of the pot wall to cause a concentration of the heat on said selected area of the pot wall.

2. The method of decarbonizing a pot burner of the character described comprising causing oil to burn on the bottom of the pot, directing a jet of air under pressure into the pot in a tangental direction to cause the flames to move in a whirling blast about the pot walls, and simultaneously directing another jet of air under pres-- sure through the whirling mass of flame toward a selected area of the pot wall to cause a concentration of the heat on said selected area of the pot wall, and controlling the heat intensity by 8 moving the second jet away from or close to the whirling mass.

3. The method of decarbonizing a pot burner of the character described comprising causing oil to burn on the bottom of the pot, directing a jet of air under pressure into the pot in a tangental direction to cause the flames to move in a whirling blast about the pot walls, simultaneously directing another jet of air under pressure through the whirling mass of flames toward a selected area of the pot wall to cause a concentration of heat on said selected area of the pot wall and changing the intensity of the heat by moving the point of discharge of the second jet closer to or farther from the whirling mass of flames, and controlling the height of flame in the pot by controlling the height of a nozzle for the first jet above the bottom of the pot.

WILLIAM c. STEELE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,081,950 Eller Dec. 23, 1913 1,325,381 Silver Dec. 16, 1919 1,901,803 Davis Mar. 14, 1933 1,987,179 Chadwick Jan. 8, 1935 2,012,832 Rhein Aug. 27, 1935 2,375,598 Trosky May 8, 1945

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