IL35961A - Oil-burner system for use in domestic and industrial installations - Google Patents

Description

Oil-burner system for use in domestic and industrial installations This invention relates to an oil burner control system for the automatic control of oil and air supply and temperature in domestic and industrial oil burner installations. In hitherto known installations of this kind the control of oil and air supply and intensity of firing is carried out by the adjusting of air dampers provided in the installation which are operated either by mechanical or hydraulic means or by a separate electrical motor provided for this purpose. The provision of air dampers not only increase the cost of the installations but causes the disadvantages of needing continuous readjustment of the dampers and frequently causing troubles by the dampers being blocked. It is the object of this invention to eliminate entirely the use of air dampers to avoid the afore mentioned disadvantages and to provide a new combination for the installation of oil burners* which is much more simplified and less costly than the hitherto known ones* According to the invention there is provided an oil burner apparatus for a furnace comprising a plural-speed electrical motor, a fuel pump driven by said motor, an air blower driven by said motor, an oil burner, an air conduit leading from said air blower to said oil burner, a plurality of oil conduits from said fuel pump to said oil burner, a solenoid-actuated valve in each of said oil conduits controlling the oil flo therethrough to said burner, a temperature senror for detecting the temperature in the furnace, and control means controlled by said temperature sensor, when the temperature in the furnace exceeds a predetermined ntazimum, for reducing the speed of the motor and for closing one of said valves, thereby to reduce the quantity of air and fuel supplied to the burner.

According to the invention, there is provided an oil burner system comprising a plural-speed electrical motor, a fuel pump driven by the motor, and an air blower driven by the motor, he air blower includes an air conduit to the oil burner, and the fuel pump includes a plurality of oil conduits to the oil burner, each of which latter conduits includes a solenoii-actuated valve. A temperature sensor senses the temperature in the furnace, and, when the temperature in the furnace exceeds a predetermined one, controls means for reducing the speed of the motor and for closing one of the valves. In this manner, the quantity of air and fuel supplied to the burner is directly controlled without the use of air dampers.

In the described embodiment, the control means comprises a relay having electrical contacts in the circuit to the plural - speed electric motor and also in the circuit to the solenoid-actuated valves. The energizing circuit of the relay is controlled by electrical contacts actuated by the temperature sensor.

In the preferred embodiment described, the motor has two speeds, two solenoid-actuated valves and two oil conduits, all controlled by the relay. It will be appreciated, however, the system could include a motor having more than two speeds, more than two valves and/or more than two oil conduits, controlled by the relay or other means controlled by the temperature sensor.

The invention is herein described, somewhat diagrammatically and by way of example only, with reference to the accompanying drawing illustrating an oil burner system constructed in accordance with the invention.

The oil burner system illustrated in the drawing comprises an oil burner 2 installed in a furnace 4. In this case, the oil burner comprises a pair of fuel nozzles 6, 8 each supplied with fuel via a fuel conduit 10, 12. Burner 2 further includes an air nozzle 14 surrounding the fuel nozzles 6, 8, and supplied from air conduit 16. It is contemplated there could be a separate air nozzle 14 for each of the fuel nozzles, and also that there could be a single fuel nozzle supplied from the two fuel conduits 10, 12.

The fuel is supplied from a fuel pump 20 driven by a motor 22, and the air is supplied by an air blower 24 driven by the sane motor 22. Both the fuel pump 20 and the air blower 24 are mechanically coupled to the motor driven shaft 26 as shown schematically by the broken lines 26, 28, 30.

Motor 22 is a plural-speed motor, being shown in the drawing as a twb-epeed motor having a first winding 32, which when energized, drives the motor at low speed, and a second winding 34 which, when energized with winding 32, drives the motor at high speed. She speed of motor 22 is controlled by a relay RL having three sets of contacts, namely contacts RL-1 , RL-2 and RL-3. In the non-energized condition of relay RL (which is the condition illustrated in the drawing), contacts RL-1 and RL-2 connect both of the motor windings 32, 34 to the power supply 36» and therefore the motor 32 iB driven at high speed. In the energized condition of the relay, contacts, RL-1 and RL-2 are actuated whereby they engage the upper contacts illustrated in the drawings 30 that only winding 32 is connected to the power supply 36» whereby the motor is driven at low speed. it valve 71, V2 is included in each of the conduits 10, 12 supplying fuel from the fuel pump 20 to the two nozzles 6, 8. Each valve VI, V2 is actuated by a solenoid S1 , S2. The third set of contacts RL-3 of relay RL is in the energization circuit of solenoid S2, so that when the relay is energized, as shown in the drawing, contacts RL-3 are closed, whereby solenoid 32 is energized and its respective valve V2 is opened. Upon the de-energization of relay Rl, however, its contacts RL-3 are opened, thereby de-energizing solenoid S2 and closing its valve V2.

If desired, the energization circuit to solenoids SI and 32 may also include a manual switch, SW1 , S2, to permit the manual control of these solenoids and their respective valves V1, V2. Λ main switch SW3 is provided in the line to the power supply 36· In addition, another switch S?4 may be provided to manually control the speed of motor 22. Manual switch SW4 includes two sets of contacts* S¥4a and SW4b, bypassing the relay contacts RL-1 and RL-2. Each of the contacts SW4a, SW4b includes three positions, namely. a middle non-operating position; an upper position connecting the low speed winding 32 to the power supply; and a lower position connecting both windings 32 and 34 to the power supply for driving the motor at high speed.

The furnace 4 includes a thermostat TS for sensing the temperature within the furnace, the thermostat controlling a switch TS-1 in the energization circuit to relay EL. If desired, the furnace may also include a pressurestat PS for sensing the pressure within the furnace, the pressurestat controlling another switch PS-1 in the energization circuit of ely RL.

The burner includes an electrical igniter 40 controlled by an ignition system 42 of any conventional type.

The burner further includes a starting control 44 of known construction which, upon starting the furnace by depression of switch Sfc?3, closes switch SW5 in the energization circuit of relay RL causing same to move its contacts from the shown non-actuated position to their actuated position. The motor 22 is thus driven at low speed, which thereby vents the furnace, and valve V2 (as well as 71) is closed. At the same time, starting control 44 actuacts the ignition circuit 42 to energize the igniter 40. After a predetermined time delay (e.g.30 seconds), starting control 44 closes switch SW6 in the energization circuit of solenoid SI, whereupon valve 71 opens, so that fuel is now fed through conduit 12 to its nozzle 6 causing ignition. Motor 22 is now operating at low speed, and the fuel is only flowing through valve VI.

After another predetermined time delay (e.g. another 20 seconds^, starting control 44 opens switch SW5, de-energizing relay RL. The contacts of the relay thus return to the position shown in the drawing, wherein motor 22 is driven at high speed and both solenoids SL, S2 are energized, so that quantity of fuel, and also of air from air-blower 24· When either thermostat TS or pressurestat PS senses a predetermined maximum temperature or pressure, its respective switch TS-1 , PS-1 is closed thereby re-energizing relay EL. Relay contact RL-1 and RL-2 now connect the motor to be driven at low speed; and contacts RL-3 de-energize solenoid S2 and open its respective valve, 72· Fuel is now supplied only to nozzle 6, and the supply of fuel and air to the burner is automatically reduced* At a predetermined low temperature or pressure within the furnace, as sensed by thermostat TS, or pressurestat PS, its respective switch TS-1, PS-1 is opened thereby de-energizing relay RL and increasing the supply of fuel and air to the burner in the manner described above.

When operating the system non-automatically, switch SW4 provides for nanual control of the motor 22, and switches SW1, SW2, provide for manual control of the solenoid-valves V1, V2, as described above.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments and that the present invention may be embodied in other specific forms without departing from the spirit of essential attributes thereof, and it is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reerence being made to the appended claims rather than to the foregoing description, in w&ich it is intended to claim all modification coming within the scope and sprit of the invention. - -

Claims (6)

What is claimed is:

1. Oil burner apparatus for a furnace comprising, a plural-speed

electrical motor, a fuel pump driven by said motor* an air blower driven by said motor an oil burner, an air conduit leading from said air blower to said oil burrcr, a plurality of oil conduits from said fuel pump to said oil burner, a solenoid-actuated valve in each of said oil conduits controlling the oil flow therethrough to said burner, a temperature sensor for detecting the temperature in the furnace, and control means controlled,by said temperature sensor, when the temperature i the furnace exceeds a predetermined maximum, for reducing the speed of the motor and for closing oneof said valves, thereby to reduce the quantity of air and fuel supplied to the burner*

2* A system as defined in Claim 1, wherein said control mean comprises a relay having electrical contacts in the circuit of the motor windings and also in the circuit of a t least one of said solenoid-actuated valves, said tern-perature sensor actuating electrical contacts in the energizing circuit of said relay.

3* A system as defined in claim 2, wherein said motor has two speeds, two solenoids-actuated valves, and two oil conduits, all controlled by said relay* 4* A system as defined in Claim 3» wherein said oil burner includes two nozzles one supplied by each of said oil conduits.

5. A system as defined in Claim 1, further including a pressure sensor for detecting the pressure in the furnace, said control means also being controlled by said pressure sensor*

6. A system as defined in Claim 2, wherein said oil burner includes an electrical igniter, and wherein said system further includes starting control means which, upon starting the furnace, energizes said relay to cause the motor to run at low speed and also energizes the electrical ignitor; after a predetermined time delay opens oneof said valves to cause a reduced amount

of fuel to be fed to the burner; and after another predetermined time delay de-energizes said relay to cause the motor to run at high speed and fuel to be fed through both said valves to the burner; the temperature sensor thereafter controlling said relay whenever the temperature exceeds a predetermined maximum.

7· Oilburner apparatus for furnace installations substantially as hereinbefore described with re erence to the attached drawing*

For the Applicant

Wolff, Bregmas and Goller