US2461991A - Oil by-pass structure to avoid smoking of oil burners - Google Patents

Description

Feb. 15, 1949. J. A. LOGAN OIL BY-PASS STRUCTURE TO AVOID SMOKING OF OIL BURNERS Filed Jan. 25, 1946 INVENTOR Joan/1 A. L oeA/v ATTORNEYS on. BY-PASS STRUCTURE 'ro Av'om SMOKING or on. BURNERS Joseph A. Logan, Hadley, Mam, minor to Gilbert & Barker Manufacturing Company, West Springfield, Mass a corporation of Massachusetts Application January 25, 1946, Serial No. 43,221

'This invention relates to improvements in-oil burners, particularly of the house heating automatic type of oil pressure atomizlng burner controlled by a thermostat. I

According to the invention anew combination of structure provides for a new mode of operation to avoid smoking in the starting and stopping I periods of the automatic burner operation.

The idea is to automatically provide excess air for the starting and stopping periods, so that the burner may be adjusted for the most efficient air-oil ratio for the running operations. There are other ways known in the art to do this. This invention is for a new, useful, and very economical way to get the advantage of excess air as mentioned. Such excess air avoids smoking in the short starting and stopping operations. cient air-oil ratio for long burning periods is one in which a slight air increase in the ratio will give a substantial decrease. of oil heating efliciency and a slight air decrease will give not only a substantial decrease in efficiency but also an amount of smoke which is objectionable for many reasons. This situation is understood in the art. It is mentioned as a known situation to be taken into account in the disclosure and understanding of this invention.

An example of the present invention is disclosed in the drawings. Its relation to the burner, its mode of operation, and some of the advantages will be shown as the example is described.

In the drawings:

Fig. 1 indicates generally a type of burner to which the invention may be applied;

Fig. 2 a diagrammatic view showing the main elements of the invention and indicating how to apply the new elements to the burner of Fig. 1 to provide the new combination; and

Fig. 3 is an enlarged view of the valve structure shown in Fig. 2.

Referring to Fig. 2, a pump I draws ,oil from a source of supply 2 and applies it under pressure to a pressure regulating valve generally designated by numeral 3. The latter is adjusted to open under a predetermined pressure and fuel oil is forced to a nozzle supply pipe I to atomize the oil under this predetermined constant pressure. In the type of regulating valve shown, a valve piece 5 is forced by the oil pressure against an adjustable spring 6, which spring is urging An eiii- 2 Claims. (Cl. 158-363) the valve against a port I leading to pipe 4 and normally closing ofi this passage to the nozzle. As the pump customarily has excess capacity, part of the oil is by-passed by the valve back around the pump through pipe 8 either to its supply tank or to the inlet side of the pump, all according to the desired piping arrangement.

The connection here shown is to the tank 2. In

the vavle the excess oil is by-passed' through passage H) which comes, when the oil pump is exerting more than the required pressure, into registration with passage H thereby establishing connection with pipe 8. So far the showing in the example is conventional structure.

The new structure is seen in the example as a special by-pass conduit I 2 from the outlet to the inlet side [3 of the pump with a control valve, generally designated by numeral It, to restrict flow in this by.-pass conduit.

This control valve l4 of the example consists of a casing l5 holding a diaphragm t6 having a boss I! perforated at the center with a small hole l8 through the diaphragm l6 and boss ll. Opposite the boss is an adjustable closing disk It for the hole l8. The disk is adjustable by a threaded stem 20 which supports it. The stem 20 extends through the casing in which it is threaded to be turned from without the casing to adjust the closing disk. A spring 2| around.

the stem between the casing wall l5 and the diaphragm l6 resists movement of the diaphragm in a direction to have its hole closed by said disk.

The size of the diaphragm hole is chosen with the following operation in mind. When the pump starts to discharge oil, tending to open the pressure regulating valve, to feed oil to the nozzle. the pressure regulating valve 3 will be delayed in opening, by the special by-pass with the diaphragm valve device, in this way. With the hole open the path of least resistance, when the pump starts, is through the by-pass l2 and diaphragm casing back to the inlet side of the pump. This way is open while the pressure regulating valve is ,closed. As long as the oil pressure canfind relief through the by-pass back to the inlet side of the pump, such pressure can not build up to open the pressure regulating valve and supply oil to the nozzle for-combustion. The diaphragm hole can be sized, however, to pass less oil to the low pressure side of the diaphragm than is re 3 ceived from the pump on the high pressure side of the diaphragm. In such a case the pressure will accummulate on the high pressure side of the diaphragm and gradually press it toward that position where its hole is closed by the disk. In this way the device is made to delay the pump building up sumcient pressure to open the regulating valve to supply the nozzle. The important thing is the size of the restriction in the by-pass and not the closing off of the by-pass. The shutting of the valve avoids by-passing oil with no particular purpose. In the broadest aspect of the invention the by-pass could. be left open but restricted. i. e. by the hole IS without its closure. But I now prefer the structure shown.

As the customary burner (Fig. 1) has its motor 22, fan 23, and oil pump I, on one shaft 24 for simultaneous starting, running,and stopping operations, the special by-pass with its timing diaphragm valve is all that needs be added in the combination to time the arrival of the oil supply at its atomizing pressure for mixing with the air at the ignition zone for combustion. Customary electrodes for the ignition zone are shown in Fig. 1. The diaphragm valve is a hydraulically operated device to delay the oil supply to this ignition zone.

This delay in the operation of supplying oil is to permit the air supply from the fan to get under substantially full momentum at the ignition zone, before the oil supply arrives at that zone. The rate of supply of either air or oil is a factor in their ratio for combustion. In the structure disclosed there is excess air, 1. e. a substantially full supply without any oil mixing with it at the time the oil first arrives to start the bumer. The first injection of oil into this excess air is enough to start the burner, since the ignition is operating to start a flame the instant there is enough oil to do this. The flame will start with excess air to avoid smoke and the oil supply wfll in a succeeding fraction of a second reach its full supply in the quantity which wfll establish the eiflcient combustion ratio of air and oil during the running period. The burner can be adjusted for such ratio while the combination described 4 prevent it. My added diaphragm, relieving the pump of its pressure output, will act in the combination as a new way to prevent the regulating valve from opening. The supply of oil under pres-- sure will then cease to pass through the nozzle conduit altogether, once the motor is turned oil. The regulating valve once closed will remain closed. In relieving the pump of pressure on the outlet side another benefit also results in the pump operating with less resistance during the motor shut down period. While the pump turns with less resistance, the momentum of the motor shaft and parts on it, is that much less affected.

Consequently, the added reserve of momentum will be utilized to keep the fan operating so much longer. The added fan operation will supply excess air for any dying down flame possible with 7 any few drops of oil needing to burn oil after the provides for excess air at the starting period to avoid smoking.

When the motor is shut off there is an instant drop of pressure in the oil discharge due to the drop in the power of the motor drive. It is enough to permit the spring to push the diaphragm I6 from its hole-closing position. As the hole I8 is opened there is a further relief of discharge pressure through the by-pass. This acts to at least partially unload the pump. Both these causes in pressure drop are available to drop the pressure quickly below that point necessary to hold the regulating valve 3 open. This results in a quicker closing of that valve than when the special by-pass is not used. The special by-pass diaphragm arrangement furthermore results in avoiding the hunting effect or intermittent opening and closing of such regulating valve which is common when the motor is turned off and the parts on its shaft coast before stopping. This hunting is caused by the continued turning of the motor shaft coasting to rest and the consequent turning of the pump parts to create a pressure in the outlet side. When valve 3 is closed, the pressure builds up, then the valve is opened again. This tends to open and close the pressure regulating valve intermittently and dribble oil through the nozzle outlet in the prior art practice, unless a special means is used to oil supply is otherwise shut 011'. Thus the shutting down period of the burner operation will be under conditions of excess air to oil so as to avoid smoking entirely.

One of the advantages to be considered is the simple and easy installation of the device. It may be adapted to the type of burner generally considered. It is necessary only to add the special pump by-pass arrangement with a restriction or control valve indicated in the example. The type of burner can be otherwise undisturbed in its hydraulic and particularly in its mechanical and electrical construction. The new element to be added is essentially a hydraulic device as distinguished from mechanical or electrical.

Having disclosed my invention, its scope is pointed out in the following claims:

I claim:

1. An automatic oil pressure atomizing burner including a motor driven fan and oil pump, a regulating valve for constant atomizing pressure, a nozzle having an atomizing outlet adjacent the air outlet from the'fan; and in combination a by-pass conduit between the high pressure side of the regulating valve and the low pressure side of the pump, a valve in said conduit to restrict flow therethrough, said valve comprising a casing, a diaphragm separating the casing into high and low pressure sides and provided with a port for connecting said two sides of the pump, an adjustably mounted closure for said port, a spring, biased to hold the diaphragm away from said closure, said port being of a size adapted to permit the pump to gradually build up pressure in the high side of the valve casing which will move the diaphragm against the spring and its port against its closure.

2. A motor driven automatic oil pressure atomizing burner including a motor, a fan, and oil pump, a pump driven by said motor discharge conduit with a regulating valve therein for contant atomizing pressure and a nozzle at the end thereof provided with an atomizing outlet, and means to conduct the air supply of said fan past said nozzle outlet, in combination with an oil by-pass conduit, said conduit having its by-pass inlet in said pump discharge conduit in advance of the inlet to said regulating valve and its by-pass outlet connected to the suction side of the pump, said by-pass hav ing a valve therein for a restricted passage of oil under pressure from the pump, said valve comprising a casing, a movable wall separating the casing into high and low pressure sides and provided with a port for connecting the two sides, a closure mounted in position to close said port,

yieldable means biased to hold the movable wall 5 6 away from said closure, said port being of a size REFERENCES CITED to permit the pump to build up pressure gradually in the high side of the valve casing to move said The fOlIOWlng e e ce are of record I t wall and port against its closure whereby the valve file Of this p t: will be adapted to time the beginning and. shutting UNITED STATES PATENTS off of oil delivery through the regulating valve so as to permit air delivery by said fan without oil Number Name Date delivery to said nOZZle for short periods in starting 1,482,759 Meyers 1924 up and shutting down operation of the burner. 1,820,612 Good et a1 1931 10 1,824,952 Graham et a1 Sept. 29, 1931 JOSEPH LQGAN 2,178,6'7 2 Perkins NOV. '7, 1939

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