JPH0351617Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a combustion device for liquid fuel used for heating purposes, and particularly to a vaporization type combustion device.

[Prior Art] There is no known liquid fuel combustion device that heats liquid fuel such as kerosene with a vaporizer with a built-in heater, and injects the obtained vaporized gas into a burner through a nozzle communicating with the vaporizer for combustion. be.

An example of such a liquid fuel combustion device will be explained with reference to FIG.
The gas is heated and vaporized to form a vaporized gas, which is vigorously jetted toward the mixing tube 7 of the burner 6 from the nozzle 5, which is the only one communicating with the atmosphere. Further, the primary air sucked into the mixing tube 7 by the negative pressure caused by the jet flow of the vaporized gas mixes with the vaporized gas to form a mixed gas, which flows out from the vent 8 of the burner 6 and is combusted.

The nozzle 5 is opened and closed by a needle valve 11 at the tip of a valve rod 10 that is controlled by a solenoid 9, and during stoppage and preheating, the nozzle 5 is opened and closed by a needle valve 11 at the tip of a valve rod 10, and during stoppage and preheating, the nozzle 5 is opened and closed by the fuel or vaporized gas (hereinafter referred to as residual fuel) in the vaporization chamber 3. ) is closed to prevent it from flowing out from the nozzle 5. In addition, the temperature of the remaining fuel increases and expands due to preheating, and if this continues, the pressure inside the carburetor 2 will increase, and if the limit is exceeded, the pressure inside the carburetor 2 will increase.
A return pipe 12 is provided to release the pressure to the outside of the vaporizer 2, since this may cause damage to the vaporizer. Further, a return valve 13 is configured within the vaporizer 2, and the return valve 13 is closed at the same time as the nozzle 5 is opened.

Note that, unlike the embodiment, a solenoid valve may be provided in the middle of the return pipe 12 instead of the return valve 13, and the solenoid valve may be closed in conjunction with the opening of the nozzle 5.

By the way, in the conventional liquid fuel combustion apparatus configured in this way, the vaporization chamber 3 during preheating is connected to the return valve 1.
3. Since it communicates with the atmosphere through the return pipe 12 and the oil storage section 14, the internal pressure is slightly higher than the atmospheric pressure. By the time preheating is completed, most of the remaining fuel becomes vaporized gas and returns to the oil storage section 14, but some vaporized gas that cannot be returned to the oil storage section 14 remains in the vaporization chamber 3. . When a control circuit (not shown) determines the completion of preheating, that is, the start of combustion, based on the signal from the thermistor 15 attached to the carburetor 2,
The pump 1 is started by a command from the control circuit, and the valve rod 10 is attracted by energizing the solenoid 9, and the nozzle 5 is opened. The vaporized gas ejected from the nozzle 5 immediately after the nozzle 5 is opened is
This is a diluted gas remaining in the vaporization chamber 3, and this gas is pushed out and ejected by the vaporization and expansion of the fuel flowing into the vaporizer from the pump 1. For this reason, the force of the vaporized gas ejected immediately after opening is relatively weak, the amount of mixed gas flowing out from the crater 8 is not sufficient, and the mixed gas is also diluted in concentration, so the ignitability cannot be said to be good. It was hot. Furthermore, the return valve 13 is required to have sealing properties to prevent leakage of vaporized gas during combustion, durability against repeated impacts, etc., and therefore tends to be expensive in terms of cost.

[Problems to be solved] In view of the above-mentioned circumstances, the present invention aims to improve the ignition performance by increasing the concentration and ejection force of vaporized gas at the start of combustion, and to provide a low-cost liquid fuel combustion device by simplifying the structure. This is what I am trying to do.

[Means for solving the problem] In order to achieve the above object, this invention preheats the vaporizer with a built-in heater, and when the vaporizer temperature rises to a certain temperature, a nozzle installed at the tip of the vaporizer is activated. It is a liquid fuel combustion device that burns the vaporized gas obtained by heating and vaporizing the liquid fuel that is pumped from the oil storage section to the vaporizer by a pump and ejects it from a nozzle to a burner. In a liquid fuel combustion device that has a structure in which the remaining fuel in the vaporizer is returned to the oil storage part through a return pipe that communicates the vaporizer with the oil storage part, the internal pressure of the vaporizer during preheating is recorded in the return pipe. It consists of a pressure valve that opens at a constant pressure to maintain a constant pressure.

With such a configuration, a pressure valve that opens when a certain pressure is applied is provided in the path of the return pipe 12 that communicates the vaporizer 2 and the oil storage section 15, so that the temperature of the vaporizer remains constant during preheating. When the internal pressure due to the rise exceeds the set pressure, the pressure can be released to keep the internal pressure of the carburetor constant, and the amount of mixed gas ejected immediately after the nozzle 5 is opened can be increased to improve ignitability.

[Example] Hereinafter, an example of the liquid fuel combustion apparatus of the present invention will be described with reference to FIG. Incidentally, members that are the same as or correspond to those explained in FIG. 1 are given the same numbers, and detailed explanations are omitted.

A pressure valve 16 is provided in the middle of the return pipe 12. The pressure valve 16 opens when the internal pressure of the vaporizer 2 rises above a certain pressure, and the pressure valve 16 opens when the internal pressure of the vaporizer 2 increases to a certain pressure or more.
It connects the two.

Here, in the state during combustion shown in FIG. 2, the internal pressure of the vaporization chamber 3 is used to jet the vaporized gas from the nozzle 5, so it does not rise enough to open the pressure valve 16. However, During preheating, the internal pressure gradually increases as the temperature of the vaporizer 2 increases, and finally the pressure valve 16 temporarily opens, so that the internal pressure is adjusted to a constant pressure higher than before when preheating is completed. . Therefore, the amount of residual vaporized gas can be increased, and at the time of ignition, the amount of vaporized gas ejected increases, improving ignition performance. Even if the return valve 13 is not provided, combustion can be performed safely without damaging the carburetor 2 as in the conventional case.

It goes without saying that the pump 1 has a structure that does not cause backflow even when the pressure valve 16 is opened.

[Effects of the invention] As explained above, the liquid fuel combustion device of the invention is equipped with a pressure valve that opens at a certain pressure in the middle of the return pipe that communicates the vaporizer with the oil storage part. It has the following effects.

At the start of combustion, vaporized gas is ejected from a state where the internal pressure of the vaporizer is increased, so a large amount of vaporized gas is ejected, and at the same time, a large amount of mixed gas flows out into the burner's crater in a short period of time while sucking primary air. , ignitability is improved.

By providing a pressure valve, there is no need for a return valve, and there is no need to ensure sealing during suction or durability against repeated impacts, which is required for return valves, so costs can be reduced, and the structure is simple. Failure rate decreases.

During preheating, the pressure inside the vaporization chamber is high and the presence of relatively high concentration vaporized gas increases the thermal conductivity within the vaporization chamber, increasing the speed at which heat from the heater is transferred to the outer circumference of the vaporizer and the thermistor. This will shorten the preheating time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional liquid fuel combustion apparatus, and FIG. 2 is a block diagram of a liquid fuel combustion apparatus according to the present invention. 12...Return pipe, 16...Pressure valve.

Claims (1)

[Scope of utility model registration request] The built-in heater preheats the vaporizer, and when the vaporizer temperature rises to a certain temperature, the nozzle installed at the tip of the vaporizer is opened, and the liquid fuel pumped from the oil storage section to the vaporizer by the pump is heated. , a liquid fuel combustion device that performs combustion by ejecting vaporized gas obtained by vaporization to a burner from a nozzle, and further includes a return pipe that connects the fuel remaining in the vaporizer during preheating to the vaporizer and the oil storage section. In a liquid fuel combustion device having a structure in which oil is returned to an oil storage part at a fuel tank, a pressure valve that opens at a constant pressure is provided in the return pipe to maintain a constant internal pressure of the vaporizer during preheating. liquid fuel combustion equipment.