JP2663443B2 - Fluid fuel combustion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention eliminates a local overheating phenomenon in a combustion chamber, particularly a combustion cylinder made of a heat-resistant steel plate constituting a combustion chamber having a forced ventilation path space around the combustion chamber. The present invention relates to a fluid fuel combustion device capable of obtaining a uniform temperature distribution with a small difference in surface temperature between upper and lower portions. (Prior Art) In the case of a fluid fuel combustion device, particularly a device in which a liquid fuel is spray-burned by a burner, the heat transfer in the combustion chamber is mainly performed by radiant heat transfer from a burner bright flame. "Combustion Equipment Engineering, first edition published on September 10, 1967, October 30, 1973
5th edition, daily, Nikkan Kogyo Shimbun, 114, 115 pages, "
However, since this heat transfer form is determined by the flame shape and the degree of completion of combustion, the shape of the combustion cylinder that constitutes the combustion chamber is affected by radiation heat transfer. Therefore, at present, various measures have been devised in order to obtain a uniform surface temperature distribution. By the way, most of the combustion cylinders (8) of this kind of combustion apparatus, which are frequently used, have a cylindrical shape with a top, which is disposed so as to be able to break through a flame opening (6) of a burner (5). The structure is such that the tube (8) itself is red-heated to obtain radiant heat (see FIG. 7 (a)). (Problems to be Solved by the Invention) As apparent from the diagram of FIG. 7 (b), the conventional combustion apparatus described above shows that the distribution of the surface temperature in the combustion cylinder (8) is 6), the highest temperature is at the closest side (A), and the lowest temperature is at the side (B) near the top.
The temperature difference between the highest temperature and the lowest temperature is remarkably non-uniform, and as a result, in the superheated area (A), the temperature reaches the heat-resistant temperature of the combustion tube material, causing distortion and deterioration. On the other hand, on the other hand, the portion (B), which is a low-temperature region, causes a decrease in heat transfer efficiency, and when used in a heater or the like, there is a drawback in that an increase in operating cost due to a decrease in heating efficiency and a short life are caused. . SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and it is an object of the present invention to additionally dispose a radiation cylinder having a simple structure in a combustion chamber such as a heater having a forced ventilation path space around the combustion chamber. Accordingly, it is an object of the present invention to make the surface temperature in the combustion cylinder uniform, thereby improving the heating efficiency. (Means for Solving the Problems) As will be apparent from the drawings showing the embodiments, the present invention relates to a combustion cylinder (7) made of a heat-resistant steel plate constituting a combustion chamber (7) having a forced ventilation path space around it. 8. A fluid fuel combustion device comprising a burner (5) at a required length above a burner (5), wherein a burner (5) is provided in a lower half portion of a combustion chamber (7) of the combustion cylinder (8).
A short cylindrical radiating cylinder (1) surrounds the flame opening (6) of the
1) is set up substantially concentrically on the combustion cylinder (8), and the radiating cylinder (11) is made of a stainless steel sheet having a large number of cuts in a staggered arrangement, and It is made of a lath material having a large number of corrugated holes (12) formed by pulling in the plane direction, and the large number of corrugated holes (12) direct each hole axis direction from the inside of the cylinder to the outside. It is characterized by being erected so as to be directed obliquely upward. (Effect) The present invention provides a flaring tube (1) made of a lath material in the vicinity of a combustion flame.
By surrounding in 1), the direct radiation from the flame to the combustion cylinder (8) is reduced to eliminate the heating zone, and the reduced direct radiation from the flame and the hole (12) in the radiation cylinder (11) are reduced.
The surface temperature of each part of the combustion cylinder (8) is made uniform by synergistic action with solid radiation by raising the surface temperature of the radiation cylinder (11) by convective heat transfer using the leading edge effect of the surrounding rim material. The temperature distribution is improved. (Example) Hereinafter, an example of the present invention is described based on an accompanying drawing. 1 and 2 show a hot air heater according to an embodiment of the present invention, in which a vertically long stationary casing (1) has a suction grill (2) at a lower front portion and a blow grill ( 3)
And the interior is divided into upper and lower chambers of a fan chamber and a heat exchange chamber, and a convection fan (4) is housed in the fan chamber facing the intake grill (2), while a blow-off grill (3) is provided. ), A burner (5), a combustion tube (8) constituting a combustion chamber (7) facing a flame port (6) of the burner (5), a heat exchanger (9) and a control. Department (10)
Has been acquired. When the convection fan (4) is driven and the burner (5) is driven to burn, the room air is blown from the suction grill (2) and dust is removed by an air filter (not shown). The air flows through the convection fan (4), around the burner (5) and around the combustion chamber (7) in order, and is blown from the blow grill (3) toward the room. The air is heated in the combustion chamber (7) and the heat exchanger (9) and is blown out as hot air. Although not shown, the burner (5) has an oil leveler connected to the outlet, and an air supply pipe extending from the air supply / exhaust cylinder to the air supply port, so that outdoor air is supplied as combustion air. Kerosene is supplied as fuel through the oil leveler. On the other hand, the combustion chamber (7) is provided with an outlet for sending out combustion gas at the upper part of the back wall of the combustion tube (8), and this outlet is connected to the inlet of an air-to-gas heat exchanger (9). The outlet of the heat exchanger (9) is connected to an exhaust pipe of a supply / exhaust pipe via an exhaust pipe so that the exhaust gas after combustion is discharged to the outside so that the exhaust gas does not flow into the room. A so-called clean combustion / exhaust type heater that does not contaminate the air with combustion air can be obtained. The combustion device in the heater having such a configuration has a burner (5) and a combustion tube (8) constituting a combustion chamber (7) as an element member.
300mm, body length 466mm) made of heat-resistant steel plate. For example, the top plate is made of bare aluminum plating plate, and the body plate is made of blackened aluminum plating steel plate, and the combustion gas leaks. It is erected on top of the burner (5) while keeping airtight so that it does not leak. In the combustion chamber (7), as shown in FIG. 3, a radiating tube (11) is arranged concentrically with the combustion tube (8). The radiating tube (11) is, for example, 150 mm in diameter and 98 mm in body length. And is erected around the flame port (6). In contrast, the radiation cylinder (11) is formed from a plate having no holes, because the combustion cylinder (8) needs to cut off the combustion chamber (7) and its surrounding space. Since it is necessary to pass the combustion gas, it is formed from a perforated plate. The irradiation cylinder (11) according to the present invention is made of a material having a remarkably superior heat resistance compared with the combustion cylinder (8), and is a heat-resistant stainless steel plate equivalent to 310S in JIS standard, for example, 0.8 mm thick. A lath member formed from the above plate body is assembled into a cylinder. The above-mentioned lath material has a structure similar to a lath used in the construction field as a wall base material. After a number of short cuts are formed in a staggered arrangement on a heat-resistant stainless steel plate, the cut is pulled in a direction perpendicular to the plate material surface. As a result, a perforated plate having a large number of horizontally long diamond-shaped holes (12) arranged in a staggered arrangement as shown in FIG. 4 is formed. The characteristic of such a lath material is that a perforated plate formed by punching many holes from a flat plate is a flat plate itself,
The axis of each hole is, of course, orthogonal to the plate surface. In addition, a square plate having two sides corresponding to the circumference and the body length is required for manufacturing, and the material is large. The required cylindrical body can be obtained from a two-sided rectangular plate slightly longer than the circumference and much shorter than the trunk length, and the material surface can be saved.
As shown in the cross section in the figure, the direction of the hole axis of each hole (12) crosses the plate surface obliquely, and when disposed around the flame opening (6), it is directed obliquely upward from inside to outside. There are two points. The use of the radiating cylinder (11) having the above-described structure is the best when the flame opening (6) is surrounded in the combustion chamber (7) and a cylindrical member or a hot plate is interposed. From the experimental results that the temperature point (A) moves upward, it is clear that solid radiation is generated by blocking gas radiation by using a perforated cylinder or a hot plate. There is no other way of thinking that the two advantages of being able to prevent the temperature of the lower part of the combustion cylinder (8) from being lowered by raising the temperature of the radiation cylinder (11) itself by passing the gas radiation are utilized. . When a combustion experiment was actually performed with the radiation tube (11) provided, solid radiation of the radiation tube (11) was generated by partially blocking gas radiation, which was more advantageous than gas radiation in terms of radiation rate. Since the radiation is performed, the temperature of the upper part of the combustion tube (8) can be increased, and furthermore, part of the combustion gas passes through the hole (12), so that the radiation tube (11) itself is wrapped in the combustion gas. As shown in FIG. 6 (b), the surface temperature of the combustion cylinder (8) can be made uniform at each part from the lower part to the upper part, and the temperature distribution can be improved. Was peeled off. The axial direction of each hole (12) in the irradiation tube (11) is directed obliquely upward from the inside to the outside of the tube, as shown in cross-section in FIG. 5 and schematically shown in FIG. Thus, the arrangement of the radiating cylinder (11) promotes the convection of the combustion gas passing therethrough, and at the same time, the leading edge effect of the rim material around the hole (12) is combined with the surface temperature of the radiating cylinder (11). The feature that can further enhance was exhibited. (Effects of the Invention) The present invention is configured as described above, and a radiating cylinder (11) for effectively obtaining solid radiation is burned in a lower half portion of a combustion cylinder (8) with a lath material. As is apparent from the above description, the erect portion is set up so as to surround the flame outlet portion (6) of (5), and the plurality of holes are directed obliquely upward with the hole axis direction directed from the inside to the outside. The temperature distribution is improved so that the surface temperature of the combustion tube (8) becomes substantially uniform in each part. For example, a home-use hot air heater having a kerosene gasification burner according to the present invention and a conventional hot air heater can be used. As a result, the maximum temperature of the combustion cylinder (8) was 64
Although the temperature difference was large at 0 ° C and the minimum temperature of 380 ° C,
In the case where the projection tube (11) according to the present invention is provided, approximately 44
A uniform temperature distribution of around 0 ° C. was obtained, which clearly showed improvement. As a result, it is possible to prevent local overheating of the combustion tube (8), prolong the service life, improve the radiation efficiency by preventing the occurrence of low-temperature portions, and reduce the diameter of the combustion tube (8). The device can be made more compact.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a hot air heater according to an embodiment of the present invention, FIG. 2 is a front view showing the same internal structure, and FIG. FIG. 4 is a partially enlarged sectional view of the radiating cylinder shown in FIG. 3, FIG. 5 is a partially enlarged sectional view of the same radiating cylinder, and FIG. 6 (a) is a schematic diagram of a combustion apparatus according to the present invention. FIG. 6 (b) is a temperature distribution diagram corresponding to FIG. (A), FIG. 7 (a) is a schematic structural diagram of a conventional combustion device, and FIG. 7 (b) is the same diagram. It is a temperature distribution line corresponding to (a). (5) ... burner, (6) ... flame outlet, (7) ... combustion chamber, (8) ... combustion cylinder, (11) ... radiation cylinder, (12) ... hole.

Claims (1)

(57) [Claims] A fluid fuel combustion device comprising a combustion tube (8) made of a heat-resistant perforated plate and having a required length above a burner (5), constituting a combustion chamber (7) having a forced ventilation path space around the burner (5), In the lower half portion of the combustion chamber (7) of the combustion cylinder (8), a short cylindrical radiating cylinder (11) is formed so as to surround the flame opening (6) of the burner (5).
Is erected substantially concentrically on the combustion cylinder (8), and the radiating cylinder (11) is provided with a stainless steel sheet provided with a number of cuts in a staggered arrangement in a sheet surface direction perpendicular to the cuts. Multiple corrugated holes (12) formed by pulling on
And a large number of corrugated holes (12) are erected so that the axial direction of each hole is directed obliquely upward from the inside to the outside of the cylinder. Fluid fuel combustion device.