DK149698B - DEVICE FOR AUTOMATICALLY OPENING AND CLOSING OF THE AIR INFLATION CHANNEL FOR AN OIL BURNER - Google Patents

Description

149698

The present invention relates to a device for automatically opening and closing the air intake duct of an oil burner when the burner stops or starts, respectively, and to which burner belongs to a motor from which a shaft extending through the air intake duct extends and which motor drives the fan and the oil pump, which conveys air and oil to the burner. Furthermore, a movable plate is arranged for opening and closing the air intake duct arranged on the drive shaft so that when rotating the drive shaft it opens the air duct and closes it when the shaft is stopped.

10 The problem in the prior art oil burners is that when burning clean stops, the air duct remains open, whereby a considerable amount of air flows through the fireplace's fire, which is thereby cooled by the consequent considerable loss of energy. The longer the burner standstill times are in relation to the operating times, the higher the 15 resulting energy losses. If airflow could be completely prevented, this would mean oil savings of 12% in winter and 27% in summer when heating villas and small properties under Finnish conditions. Attempts have been made to prevent this cooling air flow. by means of a damper inserted in the chimney 20 which is operated by means of a damper control motor. However, to such a device there are considerable disadvantages, among other things. the risk that the damper will not open or that it will not close tightly due to soot or other contaminants. In some cases, the pressure caused by the heat has also risen so high that the ducts have opened explosively.

The object of the invention is to eliminate the above-mentioned problem without any damper built into the chimney and at minimal cost, so that the closing and opening of the air duct automatically occurs without the use of extra energy or control.

This object is achieved according to the invention in that a screw thread is arranged on the shaft which is freely rotatably enclosed by an internal screw thread in the hub of the movable plate or disc.

With the solution according to the invention, when the engine and shaft stops, the disk will then continue its rotation, whereby, due to the screw operation, it moves in the axial direction until it abuts against the walls of the air duct and thus closes the air duct. Similarly, the disc does not immediately follow because of the inertia forces when the engine starts, but a relative rotation of the shaft relative to the disc takes place, whereby the disc is moved back to the position releasing the channel.

The invention will now be described in more detail with reference to the accompanying drawing, which shows the latter advantageous embodiment of the invention in a schematic section.

By means of shaft 2, motor 1 rotates fan 3 and oil pump 4. By reference number 6 is denoted the stepwise or conically narrowing air intake duct ending in the cavity formed within the blades 3 of fan 3.

According to the invention, the shaft 2 is provided with screw 7 and the circular disc 8 is rotatably rotatable about the screw section 7 by means of a hub 9 provided with corresponding internal screw thread. When the motor 1 stops, the disc 8 and the hub 9 continue its rotation. thanks to the kinetic energy stored therein.

Hereby, the disk 8 moves from the right to the left by closing the screw 7 in the figure and closes the air duct 6. When the engine 1 starts, the disk 8 does not immediately achieve the same rotational speed, whereby the disk 8, due to the relative rotation of the shaft 2 and the disc 8 relative to each other, moves from left to right in the figure, ie. to the position shown in the figure, releasing the air duct 6. A screw stop 7 can be fitted with a suitable stop pin 10 with such a design of the screw passage in the hub 9 that it runs against this pin, whereby no clamping takes place but the disc 8 is always freely and easily rotatable.