JPH06117623A - Method for controlling vaporizing burner - Google Patents

Abstract

PURPOSE:To clean a vaporizer efficiently and definitely at the time of fire extinction. CONSTITUTION:This is a method for controlling a vaporizing combustion device which switches over the drive frequency of a fuel return pump 20 in fire extinction mode based on a step by step process in conformity with the temperature of a vaporizer 2 in terms of a combustion device which interposes a reserve tank 11 between a fuel supply pump 3 and a vaporizer 2 in a fuel supply line 4 and installs the fuel return pump 20 to the fuel return line 10 from the reserve tank 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a fuel tank for temporarily holding fuel in a fuel supply path to a carburetor so that fuel can be fed from the reserve tank side to the main fuel reservoir side. The present invention relates to a control method for a vaporization type combustion device provided with a pump.

[0002]

2. Description of the Related Art Although an application has not yet been published, the present applicant has previously proposed a vaporization type combustion apparatus which can clean the inside of a vaporizer at the time of extinguishing a fire or in a timely manner as shown in FIG.
As shown in FIG. 3, a reserve tank 24 for temporarily holding the fuel is interposed in a fuel supply passage 23 between the fuel supply pump 21 and the carburetor 22, and a bottom portion of the reserve tank 24 is provided with a fuel return passage 25. A vaporization combustion device connected to the main fuel reservoir 26 has been proposed. In this device, the fuel in the reserve tank 24 is returned to the main fuel reservoir 26 by gravity, that is, natural fall, by opening the opening / closing valve 27 provided in the fuel return passage 25 at the time of fire extinguishing, and the carburetor accordingly. The air is drawn in from 22 to suck the residual gas in the vaporizer for cleaning.

However, in the above-mentioned proposal, in order to return the fuel in the reserve tank, the gravity falling gravity method is adopted. For this reason, a certain degree of drop is required, and the positional relationship between the carburetor and the reserve tank and the positional relationship between the reserve tank and the main fuel reservoir can be restricted, which reduces design freedom and lowers the drop speed. There is a problem that variations easily occur and cleaning effects also easily vary.

To address this problem, although the application has not yet been published, the applicant of the present invention further provided a fuel return pump in place of the on-off valve 27 in the fuel return passage, and the fuel return pump was installed. A vaporization type combustion device has been proposed which is operated to forcibly feed the fuel in the reserve tank to the main fuel reservoir. In this device, at the time of fire extinguishing and timely (for example, seasonal) cleaning of the carburetor, the fuel return pump provided in the fuel return passage is operated to force the fuel in the reserve tank to the main fuel. Since it can be fed to the reservoir, the positional relationship between the carburetor and the reserve tank, and the positional relationship between the reserve tank and the main fuel reservoir can be set to be completely arbitrary, and the degree of freedom in design is not restricted.

Further, in the case of the fuel returning system using the natural fall, the falling speed is changed due to various factors (for example, the change of the fuel viscosity due to the change of the temperature), and the cleaning effect cannot be constantly obtained. . However, in the above-mentioned proposal, since the falling speed is always kept at a predetermined constant speed by providing the electromagnetic pump, the cleaning effect can always be stably obtained.

[0006]

However, in the above proposal, since the fuel return pump is activated and the operation of the fuel supply pump is immediately stopped at the time of starting the fire extinguishing mode, the following problems occur. There was a fear. That is, as shown in FIG.
In No. 1, the fuel return pump provided in the fuel return passage from the reserve tank was operated, and at the same time, the operation of the fuel supply pump was stopped. At the time of extinguishing, the temperature Tk of the vaporizer is changed from the normal combustion temperature T1 (e.g., 300 ° C.) up to the temperature until normal combustion T1 (for example, 300 ° C.) in order to melt or evaporate the residue adhered and accumulated in the vaporizer to facilitate cleaning. It is heated and raised to a so-called baking temperature T2 (for example, 400 ° C.).

When the fuel return pump is operated at the same time as the start of the fire extinguishing mode and the operation of the fuel supply pump is stopped, FIG.
As shown in, the fuel in the reserve tank is rapidly returned to the main fuel reservoir, and the air inside the carburetor is cleaned by the air drawn from the carburetor, but the carburetor temperature does not rise sufficiently. In addition, since the cleaning associated with the air drawing is performed (before the time t2 when the air-baking temperature is reached), there is a problem that the residue in the vaporizer is difficult to be removed during that time. In particular, if the amount of accumulated residue in the vaporizer is large, the residue may not be sufficiently removed.

The present invention relates to an improvement of a control method of a device provided with a fuel return pump in a fuel return passage from a reserve tank, which has been proposed by the applicant of the present invention. It is an object of the present invention to allow the cleaning operation to effectively operate after the temperature reaches, and to sufficiently and surely clean the vaporizer even when the residue accumulation amount in the vaporizer is large.

[0009]

According to the vaporization type combustion apparatus of the present invention for this purpose, the liquid fuel in the main fuel reservoir is vaporized by a fuel supply pump through a reserve tank for temporarily holding the fuel. The fuel vaporized by the vaporizer is fed to the burner through the nozzle and burned by the burner, and the bottom of the reserve tank and the main fuel reservoir are connected by the fuel return path to extinguish the fire. And a method of controlling a vaporization-type combustion apparatus in which fuel is returned from a reserve tank to a main fuel reservoir via a fuel return passage during carburetor cleaning, in the fuel return passage, fuel is reserved from the reserve tank side to the main fuel reservoir. Is provided, and the driving frequency of the fuel return pump is switched in stages until the vaporizer reaches a specified temperature.

[0010]

In the control method of the vaporization type combustion apparatus as described above, the fire extinguishing mode is started at the time of extinguishing the fire, the fuel supply pump is stopped, and the fuel return pump is started. Since the gas in the vaporizer is sucked by the initial drive of the fuel return pump, the fire can be extinguished instantaneously. At the time of initial drive, the carburetor has a predetermined temperature,
In other words, the drive frequency is switched stepwise until the temperature reaches the specified temperature, and the fuel in the reserve tank is controlled so as not to decrease sharply. Therefore, even when the vaporizer reaches the specified temperature, a considerable amount of fuel remains in the reserve tank. At this point, the drive frequency of the fuel return pump is increased to a predetermined frequency, the fuel in the reserve tank is returned to the main fuel reservoir, and along with that, air is drawn from the carburetor that has reached the specified temperature and inside the carburetor. Is efficiently and thoroughly cleaned.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a vaporization type combustion apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a main fuel reservoir that stores liquid fuel, and the main fuel reservoir 1 is a constant oil level device in which an oil level A is constantly adjusted. 2 is a vaporizer for vaporizing liquid fuel, 3 is an electromagnetic pump, is a fuel supply pump for supplying fuel from the main fuel reservoir 1 to the vaporizer 2, 4 is a fuel supply pipe, 5 is a burner for burning vaporized fuel Are shown respectively. The vaporizer 2 is heated by the heater 6 to vaporize the liquid fuel and supply the vaporized fuel from the nozzle 7 to the burner 5. A thermistor 8 detects the temperature of the vaporizer 2.

Reference numeral 11 denotes a reserve tank for temporarily holding the supplied fuel, to which a fuel supply pipe 4 (fuel supply passage) on the fuel supply pump 3 side and a fuel supply pipe 4 on the carburetor 2 side are connected. The reserve tank 11 is further connected to the main fuel reservoir 1 by a fuel return pipe 10 (fuel return passage). Further, the fuel return pipe 10 is provided with a fuel return pump 20 which is an electromagnetic pump that feeds (pressure-feeds) the fuel in the reserve tank 11 to the main fuel reservoir 1.

Reference numeral 13 denotes a control device, and the control device 1
A temperature detection signal of the carburetor 2 is sent from the thermistor 8 to 3. Further, the control device 13 heats the heater 6 of the carburetor 2 via the drive device 14, and the fuel return pump 20,
The drive of the fuel supply pump 3 is controlled. Although illustration is omitted, a switch for performing a normal fire extinguishing operation (for example, a push button switch) and a switch for seasonal carburetor cleaning, for example, are provided separately and can be selectively operated. It is like this.

The control method of the present invention is carried out as follows using the embodiment apparatus configured as described above. As shown in FIG. 2, when the fire extinguishing operation is performed and the fire extinguishing mode is started (at t1), the carburetor 2 is moved from the normal combustion temperature T1 (for example, 300 ° C.) up to the specified temperature T2 by the heater 6.
Start heating to (eg 400 ° C.).

At this time, the operation of the fuel supply pump 3 is stopped and the fuel return pump 20 starts to drive. At the time of this initial drive, the rotation speed of the drive motor of the fuel return pump 20 is kept low by supplying the current to the fuel return pump 20 at a low frequency, and the fuel is fed from the reserve tank 11 to the main fuel reservoir 1. Fuel consumption is kept small. By this operation, as the inside of the reserve tank 11 is slightly depressurized, air is sucked from the carburetor 2, so that the fire can be completely extinguished instantly.

When the vaporizer 2 reaches the specified temperature T2, the residue attached and accumulated in the vaporizer 2 is melted or evaporated and is easily removed. At this time, if the supply current to the fuel return pump 20 is set to a high frequency and the drive motor of the fuel return pump 20 is rotated at high speed, the inside of the reserve tank 11 is suddenly depressurized and the strong suction of air accompanying it causes the vaporizer 2 The inside is cleaned. Since the residue in the vaporizer 2 is in a state of being easily removed as described above, a more efficient cleaning effect can be obtained.

That is, as shown in FIG. 3, from the start of the fire extinguishing mode (t1) until the carburetor 2 reaches the specified temperature, the fuel amount in the reserve tank 11 hardly decreases and the carburetor 2 specifies. After the temperature is reached, the temperature starts to decrease sharply, so that the cleaning operation that is substantially efficient can be started from this point (t2).

In the above embodiment, the fuel return pump 2
The drive frequency of 0 was switched to two levels (AB),
Between the start of the fire extinguishing mode (t1) and the time point (t2) at which the vaporizer 2 reaches the specified temperature, it may be possible to switch to a plurality of stages in response to the temperature rise of the vaporizer 2.

[0019]

As described above, according to the control method of the vaporization type combustion apparatus of the present invention, the driving frequency of the fuel return pump is changed stepwise after the start of the fire extinguishing mode, so that a full-scale vaporizer can be obtained. The cleaning operation can be performed after the temperature of the vaporizer has risen sufficiently, and the residue in the vaporizer can be efficiently removed. Therefore, even when a large amount of residue is accumulated in the vaporizer, the interior of the vaporizer can be cleaned more reliably, and a long-life type vaporization system can be realized.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a vaporization type combustion apparatus for carrying out a control method according to an embodiment of the present invention.

FIG. 2 is a time chart relating to one control at the time of extinguishing the fire of the apparatus of FIG.

FIG. 3 is a relationship diagram between a reserve tank fuel remaining amount and time in a fire extinguishing mode of the device of FIG.

FIG. 4 is a schematic configuration diagram of an apparatus previously proposed by the present applicant.

FIG. 5 is a time chart showing control of the apparatus of FIG.

FIG. 6 is a relationship diagram between the remaining fuel amount in the reserve tank and the time when the device of FIG.

[Explanation of symbols]

 1 Main Fuel Reservoir 2 Vaporizer 3 Fuel Supply Pump 4 Fuel Supply Channel 5 Burner 6 Vaporizer Heater 7 Nozzle 8 Thermistor 10 Fuel Return Channel (Fuel Return Pipe) 11 Reserve Tank 13 Control Device 14 Drive Unit 20 Fuel Return Pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Saito 20 Kotobukicho, Isesaki City, Gunma Sanden Co. Ltd.

Claims (2)

[Claims] 1. A liquid fuel in a main fuel reservoir is fed by a fuel supply pump to a vaporizer through a reserve tank for temporarily holding the fuel, and the fuel vaporized by the vaporizer is supplied to a nozzle. The fuel is fed to the burner through the burner and burned by the burner, and the bottom of the reserve tank and the main fuel reservoir are connected by a fuel return passage, and the main fuel reservoir is stored from the reserve tank through the fuel return passage during fire extinguishing and carburetor cleaning. In a method for controlling a vaporization-type combustion apparatus that returns fuel to a fuel tank, a fuel return pump capable of feeding fuel from the reserve tank side to the main fuel reservoir side is provided in the fuel return passage, and the vaporizer has a specified temperature. The method for controlling a vaporization type combustion apparatus is characterized in that the driving frequency of the fuel return pump is switched in stages until the temperature reaches the above. 2. The driving frequency of the fuel return pump is switched to a plurality of stages in accordance with the temperature of the carburetor.
Control method of the vaporization type combustion device.