Abstract: A hot water circulating system capable of constantly ensuring smooth and effective supply of water from an open tank to a water boiler without causing an air lock phenomenon irrespective of a variation in operating conditions of the system. In the hot water circulating system, a connection pipe is arranged between the open tank and a second communication pipe for interconnecting the water boiler and a radiator so as to directly feed water of a low temperature from the open tank to the second communication pipe.

Abstract: A hot water circulating system capable of decreasing energy loss, increasing the amount of hot water to be circulated per unit time and reducing time required for each circulating cycle. The system includes a valve opened at the start of emptying of water out of a water boiler to supply water from an open tank to the water boiler. The water boiler is divided into a heated section and a hot water receiving section arranged above and communicated with the heated section.

Abstract: A hot water circulating system capable of increasing the amount of hot water to be circulated in each circulating cycle, decreasing energy loss and improving heat efficiency. The system includes an emptiness detecting switch which is adapted to detect start of emptying of water out of a water boiler being heated to a radiator. The switch is operatively connected directly or indirectly to an on-off valve so that the valve may be opened to flow water from an open tank to the water boiler when the switch detects start of the emptying.

Abstract: The fuel supply system includes an air pipe which is connected between a fuel oil supply pipe and an inlet side of a forced air passage and is provided at a middle portion thereof with an elevation positioned above any portion of the fuel supply pipe between the air pipe and a pot of the oil burner. The fuel supply system may include an outflow prevention mechanism wherein the elevation formed at the air pipe is above the elevation of the fuel supply pipe and a return pipe, and the return pipe has an elevation positioned between the elevation of the air pipe and that of the fuel supply pipe and is connected between the oil reservoir and the fuel supply pipe.

Abstract: A safety device for an oil burner is disclosed which is capable of carrying out the detection of flame by means of a DC flame current obtained due to the rectification of flame to detect the abnormal combustion in the oil burner. The safety device includes a first flame electrode surrounded by flame of normal combustion in the oil burner and a second flame electrode arranged away from the flame and connected to an AC voltage source in a manner to be in parallel with the first flame electrode, so that the second flame electrodes cooperates with the first flame electrode to detect a failure in the flowing of a flame current through the first flame electrode or a decrease in a flame current flowing through the first flame electrode, to thereby determine any abnormal combustion in the oil burner.

Abstract: A safety device for a pot-type oil burner is disclosed which is capable of efficiently and rapidly detecting the decrease of oxygen concentration in a room due to combustion to provide a warning and/or stop the combustion by sensing the decrease in temperature of a bottom portion of a pot. The safety device includes a thermo-sensitive device arranged on the outer surface of the bottom portion of the pot which is apart from the bottom region of the pot in which occurs the vaporization of fuel oil supplied to the pot.

Abstract: A pot-type oil burner is disclosed which is capable of effectively preventing the generation of bad odor and soot during the igniting operation by turning on an electric heater positioned above a heat-resistant fabric spread on the bottom surface of a pot to previously heat the pot and fabric to a temperature sufficient to vaporize fuel oil prior to introducing fuel oil to the pot by means of a nozzle pipe.

Abstract: An oil burner comprising a safeguard mechanism against a power stoppage is disclosed which is capable of carrying out a fire extinguishing operation in a complete combustion state upon a power stoppage, to thereby prevent any soot and smelly and toxic combustion product from being produced. The oil burner includes a solenoid valve mechanism having a wiring of allowing the supply of a fuel oil to an oil supply pipe to be stopped upon a power stoppage, an air damper actuated in cooperation with a mechanism for changing the flow rate of a fuel oil supplied to the oil supply pipe, a solenoid connected to the air damper which has a wiring of allowing the air damper to be opened upon a power stoppage, and an air fan rotated due to inertia force upon a power stoppage.

Abstract: A pot-type oil burner is disclosed which is capable of stabilizing the vaporization rate of fuel oil in a pot to accomplish the stable complete combustion with a good efficiency. The oil burner is constructed to arrange a heat-resistant fabric on the bottom surface of the pot to vaporize fuel oil with a constant rate. The oil burner is also capable of significantly reducing retention of tar in the pot and facilitates removing tar from the pot as desired.

Abstract: A protective guard for a combustion appliance is disclosed which comprises a front frame having a pair of vertical frame portions between which a protective guard body is provided; a pair of side frames which at one end are rotatably supported on the vertical frame portions of said front frame on both ends thereof; and a cross beam member on both ends thereof slidably engaging the side frames. When the cross beam member is positioned at the upper ends of the side frames, the side frames are so rotatable about the axes of the upper ends of the vertical frame portions of the front frame that the side frames are able to be inwardly folded, and when the cross beam member is positioned at the lower ends of the side frames, the side frames are so fixed in an unfolded manner that they cannot be rotated. Thus, it will be noted that the protective guard can be fixed so that it can surround a combustion appliance in a stable manner.

Abstract: A red-hot type oil burner capable of effectively accomplishing uniform vaporization of a fuel oil during the normal combustion operation. A heat transfer means is provided between a combustion chamber and a vaporization chamber to transmit a part of combustion heat to the vaporization chamber. The oil burner may be provided in a mixing chamber with a diffusion plate having a cutout to allow the ignition to be rapidly and safely effected. The oil burner may be also provided with a device for preventing the generation of a bad odor. There is also disclosed a red-hot type oil burner capable of surely confirming the completion of the igniting and fire extinguishing operations.

Abstract: An oil burner of the type of pumping up a fuel oil is disclosed which has a first oil level setting means of an airtight type having an overflow pipe means constantly immersed at the lower end thereof in a fuel oil to be pumped up to the first oil level setting means and has a second oil level setting means disposed below the first oil level setting means and directly connected to a fuel oil supply tank. A fuel oil supplied from the second oil level setting means is drawn up to the first oil level setting means by a pumping-up means and subsequently supplied through a supply pipe to a combustion means. The level of a fuel oil in the first oil level setting means is kept constant at a position above the outlet end of the supply pipe. The overflow pipe means may be movable in the vertical direction so as to vary only the supply rate of a fuel oil.