JPS5997411A - Vaporizing type liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To ensure a stable combustion from the early stage of combustion, by constituting a pump with a piezoelectric ceramic material and locating a liquid pressurizing section at position at least lower than the normal liquid fuel level of fuel tank. CONSTITUTION:In an oil transfer pump 18 vertically erected at the side of tank 26 lower than the normal liquid fuel level 26a in the tank 26, a bimorph oscillator 27 will be alternately deformed in corrugated configuration, upon a conductor 35 being connected with the bimorph oscillator 27 being energized with a positive and a negative voltage of a fixed frequency. The bimorph oscillator 27 has two check valves 32, 33 provided at the fore and aft portion thereof, the check valve 32 being closed and the check valve 33 being opened upon the bimorph oscillator 27 being deformed to a recessed configuration, and thereby allowing a liquid fuel to flow into a liquid pressurizing section 30. When the bimorph oscillator 27 is deformed to a projected configuration, while the check valve 33 is closed and the check valve 32 is opened, and thereby allowing the liquid fuel to flow from the liquid pressurizing section 30 to a desired point through the check valve 32 under pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vaporized liquid fuel combustion device (for example, a petroleum heater, etc.), and particularly to the use of a pump using a piezoelectric magnetic material as a liquid fuel supply pump.

A conventional kerosene fan heater will be explained with reference to illustrated embodiments. In FIG. 1, l is a fuel tank, and an electric fuel pump 2 is attached to the upper part of the fuel tank. When the fuel pump 2 is driven, fuel is supplied to a carburetor 4 via an oil pipe 3. It has become so. The vaporizer 4 has a vaporization chamber 5, and a heater 6 that is energized and controlled by an appropriate temperature control means is attached to the outer peripheral wall of the vaporization chamber 5. During dry firing combustion, it is heated to about 420°C.

Reference numeral 7 denotes a gas injection nozzle formed in the upper part of the vaporizer 4, which injects the vaporized gas vaporized in the vaporization chamber 5 to the inlet portion side of a burner (not shown). Reference numeral 8 designates a return pipe for returning residual fuel in the carburetor 4 to the fuel tank 1 when the fire is extinguished, and the return pipe 8 includes a solenoid valve 9 which is normally closed during combustion and opened when the fire is extinguished. It is interposed.

10 is a float switch (fuel detection means) for detecting the presence or absence of fuel in the fuel tank 1, and a switch body 12;
A guide rod 18 that extends downward from the switch body 12 and has a reed switch 11 at its lower end, a float 14 that moves the guide rod 13 up and down according to the oil level, and detects moisture contained in the fuel. The guide rod 13 is provided on the lower surface of the flow chart 14.
A magnet 16 is attached to the lower end of the reed switch 11 for opening and closing.

The float switch IO has a float 14 that moves up and down depending on the position of the oil level in the fuel tank 1.
Due to the vertical movement of the reed switch 1, the magnetic force of the magnet 16
Open and close 1.

When the combustion operation is started, the oil pump 2 and the solenoid valve 9 are energized, and the oil pump 2 is driven and the solenoid valve 9 is closed. Therefore, fuel from the oil feed pump 2 is supplied into the carburetor 4 via the oil feed pipe 3. Since the carburetor 4 is heated by the heater 4 and kept at a temperature of about 250°C, the fuel supplied into the carburetor 4 is vaporized, and is supplied to the burner side through the gas injection nozzle 7 to perform the well-known combustion. Do the following.

Furthermore, when extinguishing a fire, when a fire extinguishing switch (not shown) is closed, electricity is cut off to the oil pump 2, solenoid valve 9, and heater 6, and the supply of fuel to the carburetor 4 is stopped. Since the electromagnetic valve 9 is opened, the fuel remaining in the carburetor 4 is returned to the fuel tank 1 via the return pipe 8, and the combustion flame of the burner is instantly stopped.

Oil feed pump 2 of the oil fan heater above: 5 per minute
+cc-t (A small amount of oil feeding capacity of the 5th generation is sufficient, and a large pump is not required. Rather, a large pump is inconvenient. For this reason, a rotary type that rotates an impeller by the rotational movement of a motor is used. A pump or the like is not used; instead, an electromagnetic pump is used, which is equipped with a slide and causes a piston or plunger to reciprocate using a magnetic field excited thereby.

However, this electromagnetic pump has variations in the discharge flow rate depending on the product, and also changes the discharge flow rate. Since there are variations in the change characteristics when forming the petroleum)7 heater,
It was necessary to adjust the electromagnetic pump drive circuit for each product to ensure that there were no variations in the amount of oil sent between products. or,
Since the start-up characteristics were poor and the amount of oil discharged fluctuated due to temperature changes until the solenoid temperature reached a predetermined temperature, stable combustion could not be obtained during initial combustion. Furthermore, electromagnetic pumps have the drawbacks of high noise and high cost. In this way, conventional kerosene fan heaters using electromagnetic pumps cannot sufficiently absorb variations in the capacity of individual pumps, and furthermore, due to the pump's essential defect of poor start-up characteristics, it is fatal as a kerosene fan heater. This resulted in combustion instability, which could not be overcome.

The present invention has been made to eliminate these drawbacks, and in particular uses a pump made of piezoelectric ceramic material as an oil feed pump to stabilize combustion from the initial stage of startup.

An embodiment of the present invention will be described below with reference to the drawings. Second
The figure is a schematic configuration diagram of the fan heater of the present invention. In FIG. 2, reference numeral 17 is a vaporizer main body that forms a vaporization chamber inside, and liquid fuel sent by an oil feed pump 18 (described in detail later) made of piezoelectric ceramic material passes through an oil feed pipe 19 and is vaporized. 0 vaporizer body 17 sent into the interior of the vessel body 17
is heated by a heater 20 attached to its surface, and its temperature rises, but a constant temperature is sensed by a temperature sensing element 21 via a control circuit, and the heater 20 is turned on and off to maintain a constant temperature range.

The liquid fuel sent to the high-temperature vaporizer main body 17 is gasified by the heat of the vaporizer main body 17 and injected into the burner 23 from the gas injection nozzle 22 . At this time, primary air is sucked in from around the gas injection nozzle 22, diffuses with the fuel gasified in the burner 23, and is combusted on the burner 23. During combustion, the return pipe 24 connected to the carburetor main body 17 is closed by a solenoid valve 25 to prevent liquid fuel from returning to the fuel tank 26. When combustion is stopped, the oil feed pump 18 is stopped. Then, the liquid fuel inside the carburetor main body returns to the fuel tank 26 through the return pipe 24 when the solenoid valve 25 opens. It is vertically installed on the side surface of 26, and its structure is as shown in FIGS. In Figure 3, 2
7 is a disc-shaped bimorph vibrator using a piezo element 28 as a vibrating part, and a liquid pressurizing part (
Two liquid pressurizing parts 80 are installed opposite each other in the vibrating part 30 so as to expand and contract the volume of the liquid pressurizing parts 80. 31 is a metal thin plate that constitutes the bimorph vibrator 27 together with the piezo element 28; 32 is a spherical discharge side check valve energized by a coil spring; 33 is a spherical suction side check valve energized by a coil spring; 34 is a discharge side joint, 35 is a conductor, 36 is a suction side valve seat,
37 is a joint, and 38 is a holder.

In the pump having the above structure, when positive and negative voltages of a constant frequency are applied to the conducting wire 35 connected to the bimorph oscillator 27, the bimorph oscillator 27 is deformed alternately into a concave and convex shape as shown in FIG. 2 before and after this bimorph oscillator 27
Check valve: (There are 2, 88, bimorph oscillator 27
When the pressure changes to a concave shape, the discharge side check valve 32 closes, the suction side check valve 38 opens, and liquid fuel flows into the liquid pressurizing section 301C.

Next, when the bimorph oscillator 27 changes into a convex shape, the suction side check valve 33 closes, the discharge side check valve 32 opens, and the liquid fuel in the liquid pressurizing section 80 passes through the discharge side check valve 32. be pumped.

Note that when a positive and negative voltage of a constant frequency is applied to the conductor i 35, the bimorph resonator 27 is deformed alternately into an uneven shape as shown in FIG. 4, and the magnitude Δt is the amount of deflection proportional to the magnitude of the voltage This means that the discharge flow rate of the pump can be controlled by voltage.

In the embodiment, the delivery amount can be controlled from several CC/min to several tens of CC/min.

By the way, the expansion and contraction of the piezoelectric ceramic material is very small, and if a compressible object such as air is present in the pump 18, the pressure increase due to the expansion and contraction of the piezoelectric ceramic material (bimorph vibrator 27 in the above embodiment) will be applied to the compressible object. It is absorbed and cannot contribute to liquid fuel pumping. For example, when the kerosene fan heater is initially used or when it starts up at the beginning of the season, the pump 18
Since there is air in the liquid pressurizing section 30, unless air purge is performed to fill the liquid fuel inside the pressurizing section 30, not only will the rise time become longer, but the fuel may not be pumped at all.

Therefore, in the present invention, the steady liquid level 2 of the fuel tank 26 is
When installing the pump 18 below 6a, the pump 18 is installed so that the discharge side is horizontal or above. By doing so, when fuel is supplied to the fuel tank 26, the liquid fuel flows into the pump 18 from the suction side due to the gravity of the liquid fuel, and the air in the pump 18 is automatically pushed out to the discharge side.

Next, air purging will be explained with reference to FIG. 2. Inside the oil pump 18, two bimorph oscillators 27, which move unevenly due to the expansion and contraction movement of the piezoelectric ceramic material 28, are installed facing each other, as described above. There are two check valves 82 and 33 before and after the suction side check valve 3 due to the uneven movement of the bimorph oscillator 27.
3. The discharge side check valve 32 is alternately opened and closed. However, when the Pai-Yuruf oscillator 27 is stopped, both 32 and 33 are closed by the force F. Now, when liquid fuel is supplied to the empty fuel tank 26,
The liquid fuel passes through the pipe 19a, pushes up the suction side check valve 83 by the gravity of the liquid fuel, and flows into the liquid pressurizing part 30 of the pump 18. The air 39 that was in the gap between the 02 immorph vibrators 270 flows in The liquid pushes up the discharge side check valve 32 and is purged to the outside of the pump. In this way, the minimum condition for arpurge using the gravity of liquid fuel is 2xF (pxgxsxΔh, where F is the pressing force g of the check valve, and the acceleration of gravity S is the opposite to the inner diameter of the valve seat. The internal area of contact with the stop valve p is the density of the liquid fuel Δh is the difference in height between the liquid level in the fuel tank and the valve seat of the discharge side check valve. Air purging can be performed automatically by setting the position where the height difference △h between the steady liquid level 26a and the valve seat 82a of the discharge side check valve 32 is greater than 2 F/p g s. .

As mentioned above, the pump 18 can change the delivery amount linearly with high accuracy, and has much improved accuracy compared to conventional electromagnetic pumps.Also, unlike conventional electromagnetic pumps, it does not have a solenoid, so There is no fluctuation in discharge amount due to temperature changes, and the rise characteristics are very good. Moreover, since the number of functional parts is very small, the cumulative influence of the shape accuracy of each part is small, and there is no variation between products.

Therefore, according to the oil fan heater shown in FIG. 2, combustion is stabilized from the time of startup, and the amount of combustion can be changed with high precision. Moreover, since there is no variation in the pump 18 itself, there is no need to adjust the capacity on the pump drive circuit side. Furthermore, if the pump 18 is driven once with the power supply voltage (50 or 60 cycles), almost no noise is generated, making it much quieter than before.

Further features of the pump 18 itself include: 1) The function and structure are simplified, allowing for miniaturization.

2) The conventional intermediate transmission mechanism can be omitted, eliminating loss in the intermediate transmission mechanism and achieving high efficiency.

3) It is inexpensive in terms of cost.

4) Since there are no reciprocating parts, there are no quality problems due to wear or break-in.

etc., so the quality is stable as an oil fan heater.
Higher performance and energy savings can be expected, as well as lower costs. Further, since the pump 18 is installed so that its liquid pressurizing part 30 is at least below the steady liquid level 26a of the fuel tank 26, it is necessary to fill the fuel tank 26 with fuel at the beginning of the season or at the beginning of operation. If you do so, air purge can be performed automatically, which saves you the trouble of air purge and also speeds up the start-up at the beginning of operation.

[Other Examples]

[+] Figure 5 shows a pump that uses a piezoelectric magnetic material as it is for the liquid pressurizing part. In Fig. 5, reference numeral 40 denotes a pump body, and a suction side check valve 42 is screwed to a liquid suction port 41 at the rear, a suction side valve seat 43 is screwed in a watertight manner via a packing P1, and a liquid outlet at the front. A delivery side check valve 45 is provided in the section 44.
A delivery-side joint 46 is screwed through. The check valve 4245 is a circular thin metal plate with elasticity, and small holes 42a, 42a..., 45a, 45a... for circulation are bored in the periphery of the check valve 4245. As shown, when the central portion bulges and deforms, fluid flows through the small hole 42a or 45a.

46 is a cylindrical piezoelectric material that surrounds the outer periphery of the midsection of the pump body 40 to form a pump chamber 47 (liquid pressurizing section) in the midsection, and is connected to the fixed case 48 screwed onto the main body 40. is held in place. This piezoelectric material 46 is a so-called piezo element and uses lead zirconate titanate, barium titanate, Rochelle's salt, etc. When voltage is applied, Fig. 6 (a), (b),
The diameter expands and contracts as shown in (c), and the amount of change Δt in this diameter is proportional to the magnitude of the voltage.

This Δt is about 10 to 20μ, as shown in FIG. 6(a).

In (b) and (C), it is described that the entire cylinder expands and contracts uniformly, but in reality, the middle part of the cylinder bends and moves unevenly in an arcuate manner.

Reference numeral 50.50 denotes a ring-shaped seal having a U-shaped cross section, which is fitted and adhered to the outer periphery of both ends of the cylindrical piezoelectric material 46, and the porcelain material 46 is as shown in FIGS. 6(b) and 6(c). The porcelain material 46 and the pump body 40 and the fixed case 48 are sealed watertightly by following the expansion and contraction in response to the electric signal. 51 is Patsukin. Reference numeral 52 indicates a communication passage that communicates the pump chamber 47 and the suction port 41, and 53 communicates the pump chamber 47 and the delivery port 44, respectively.

In the pump having the above structure, when an alternating current voltage of a constant frequency is applied to the piezoelectric material 46, the porcelain material 46 expands and contracts in the radial direction, increasing or decreasing the volume of the pump chamber 47, as described above. When the volume of the pump chamber 47 increases, the check valve 42 on the suction port 4I side opens and the check valve 45 on the delivery port side closes, so that liquid flows into the pump chamber 47 from the valve seat 43 side. Conversely, when the volume of the pump chamber 47 decreases, the check valve 42 closes and the check valve 45 opens, so that the liquid in the pump chamber 47 is pumped through the joint 46.

In this way, liquid can be pumped by changing the expansion and contraction of the piezoelectric material 46, but if the frequency is the same, the amount of liquid to be delivered will correspond to Δt corresponding to the voltage, and if the voltage is constant, the liquid will be pumped. , corresponds to a frequency corresponding to the number of contractions.

Therefore, the delivery amount can be controlled steplessly by linearly changing the applied alternating current voltage or the number of cycles. In the example, several CC.

It is possible to control the degree of

(2) The pump may be installed horizontally instead of vertically.

As described above, according to the present invention, combustion can be stabilized from the start of combustion, and the amount of combustion can be precisely controlled. In addition, the quality is stable and energy saving can be achieved.

In addition, the pump has a liquid pressurizing section that is connected to at least the fuel tank 2.
Since it is located below the steady liquid level 26a of No. 6, air purge can be performed dynamically at the beginning of the season or at the beginning of operation (if the fuel tank is filled with fuel). This eliminates the need for air purging.

[Brief explanation of drawings]

Figure 1: Schematic diagram of the conventional 9 oil fan heater, Figure 21
2. Schematic diagram of the construction of a single willow example of the present invention, Figure 3: Cross-sectional diagram of the oil pump portion, Figure 4: Cross-sectional diagram for explaining strain changes of the bimorph oscillator used in the oil pump, Figure 5: Cross-sectional diagram of another oil pump, Figure 6 (a),
(b), (c): Cross-sectional views for explaining strain changes in the cylindrical piezoelectric material of the same pump. Reference numeral 17: carburetor main body, 18: oil feed pump, 26: fuel tank, 27: bimorph oscillator. Agent Patent Attorney Aihiko Fukushi (and 2 others) 1st Floor Figure 2 6 Figure 3 Figure 4 Closed

Claims (1)

[Claims] 1. In a combustor that uses a pump to supply liquid fuel in a fuel tank to a vaporization section, where the vaporized gas is combusted in a burner, the pump is replaced with a piezoelectric ceramic material in the liquid pressurizing section. 1. A vaporizing liquid fuel combustion apparatus, characterized in that the liquid pressurizing section is located at least below the steady fuel level of the fuel tank.