JP2007000029A - Heating plate for oven and electric oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric oven having an enough strong furnace bed and a furnace core atmosphere of a stone kiln structure, capable of being easily subjected to temperature control, and capable of targeting baked products in a wide range. <P>SOLUTION: A heating plate for the oven comprising a fireproof brick is produced by embedding combustible bars 10a in the fireproof brick, when the brick is molded prior to baking, in such a manner that the bars penetrate the brick in a direction perpendicular to a wall thickness of the brick and are dispersed in planar view, burning the combustible bars 10a, when the brick is baked, so as to form holes 10 as remains of the burnt-out bars in the brick, and inserting resistance heating materials 11 into the holes 10, respectively. Further, baking plates 1a for lower flame and baking plates 1b for upper flame of baking furnaces are each composed of one, two, or more pieces of the heating plates for the oven. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heating plate for an oven used for baking and various cooking of confectionery, breads and pizzas, and an electric oven using the heating plate for the oven.

An oven (stone pot) using refractory bricks heats the interior of the furnace by burning firewood and gas in the firing furnace, and fires the object to be fired by the residual heat. Therefore, it is difficult to perform uniform baking due to difficulty in temperature control, and there are restrictions on the object to be fired, and it is not suitable for general cooking.
On the other hand, if an electric heating method is used that is easy to control the temperature in a stone pot oven, the hearth (refractory brick) will be heated with a heater, which requires enormous electrical energy and is not practical. An electric oven that does not have a stone pot structure is close to so-called direct-fire baking, and is not suitable for baking, for example, bread and visas that are rich in flavor.

The inventor has proposed an oven pot with an electric heating structure that basically has the advantages and features of a stone pot structure and is easy to control the temperature (see Patent Document 1 below).
The oven kettle is a natural convection type and has an electric heating structure with the advantages and characteristics of a stone kettle structure. Therefore, the lower fire firing plate and the upper fire firing plate which are the hearth of the firing furnace are connected to the far infrared ray. It was comprised with the heating plate which embedded the resistance heating body (heater) in the radiator. That is, when the resistance heating body is energized to heat the lower fire firing plate and the upper fire firing plate, the temperature in the firing furnace rises and far infrared rays emitted from the upper and lower firing plates that are infrared radiators are reflected. The temperature is made uniform in each part without forcibly convection the furnace atmosphere. Further, since the upper and lower fired plates are electrically heated and radiate heat into the furnace, the atmosphere in the furnace becomes an atmosphere close to a stone pot.
JP 2001-193933 A

The oven pot has the intended effect, but when the upper and lower fired plates are manufactured by embedding a resistance heater (heater) in the far infrared radiator, the It was necessary to sandwich a resistance heating element in a sandwich shape and join both far-infrared radiation plates.
In order to maintain the strength (particularly the strength against vertical load) of the upper and lower fired plates (far-infrared radiation plates), it is necessary to increase their thicknesses to some extent. When the resistance heating body is sandwiched between the radiation plates, the heat of the resistance heating body is difficult to be transmitted to the surface (heating heating surface) of the far-infrared radiation plate, and a large electric power is required.
On the other hand, if the resistance heating body is sandwiched between a thick far-infrared radiation plate and a thin far-infrared radiation plate to join them together, and the surface of the thin far-infrared radiation plate is used as the heating surface of the fired plate, the above problem is solved. However, the thin far-infrared radiation plate has a low strength, and the heating surface side of the fired plate becomes extremely brittle and causes other problems such as being easily broken due to cracks and the like.

The problem to be solved by the present invention is that a heating plate used in an electric heating type oven with a stone pot structure is fragile, and the purpose thereof is an electric oven having sufficient strength and excellent thermal efficiency. It is to provide a heating plate.
Another object of the present invention is to provide an electric oven in which the hearth is sufficiently robust, has a stone furnace-structured furnace atmosphere, is easy to control the temperature, and can be used for a wide range of objects to be fired. It is to provide.

  In order to solve the above problems, the oven heating plate according to the present invention embeds a combustible bar in a penetrating manner so as to be perpendicular to the thickness direction during molding before brick firing and to be dispersed in plan view, and the combustible bar during firing The main feature is that it is made of refractory bricks in which holes are formed in the combustion traces and resistance heating elements are passed through the holes.

  In order to solve the above problems, the electric oven according to the present invention is configured such that the firing plate for the lower fire and the firing plate for the upper fire are composed of one or more heating plates for the oven according to the present invention. Is the most important feature.

The heating plate for an oven according to the present invention is formed of refractory bricks in which through holes are formed so as to be perpendicular to the thickness direction and dispersed in a plan view, and resistance heating elements are passed through the holes. Since bricks form an integral plate and are not joined by overlapping a plurality of plates, the brick has sufficient strength (particularly strength against vertical load) when used for a fired floor.
Further, even when the hole is disposed close to one surface (heating surface) of the heating plate in order to increase the thermal efficiency of the resistance heating element, the heating surface side is not significantly weakened.

  In the electric oven according to the present invention, the upper and lower firing plates forming the hearth are configured by using one or a plurality of heating plates for the oven according to the present invention. It is. In addition, the upper and lower fired plates are made of refractory bricks, and the furnace atmosphere of the stone pot structure can appear by repeating heat radiation and far infrared radiation by electric heating, temperature control is easy and wide range An object to be fired can be targeted.

Hereinafter, preferred embodiments of an oven heating plate and an electric oven according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic front view illustrating an electric oven according to an embodiment of the present invention. An electric oven 5 according to this embodiment includes a first-stage baking furnace to a third-stage baking furnace 5a, 5b in one exterior body. , 5c are provided in a superposed state, and the firing furnaces 5a, 5b, 5c at each stage have doors 50 for opening and closing the front openings.
Each door 50 is a front opening type in which the lower part is connected to the lower part of the opening part by a hinge (not shown), and a viewing window 51 is installed in the substantially central part, and a handle 52 for opening / closing operation is attached to the upper central part. It has been.
A control panel 53 for controlling the temperature, humidity, lighting, and other furnace atmospheres in the furnaces is installed on the side portions of the firing furnaces 5a, 5b, 5c at each stage.

2 is an enlarged cross-sectional view of the electric oven of FIG. 1 cut so that the depth portion can be seen. FIG. 3 is a partial cross-sectional view taken along the arrow AA of FIG. And part of the second stage firing furnace 5b is shown.
In the electric oven of this embodiment, the first-stage to third-stage firing furnaces 5a to 5c are surrounded by a heat exchanger (not shown) via a heat insulating layer, and the outer surface of the heat generator is made of, for example, stainless steel. Although it is covered with the decorative board, in FIGS. 2 and 3, the exterior decorative board, the driving body, the heat insulating layer, and the front door are all omitted.

Embodiment of Heating Plate for Oven In all or a part of the firing furnaces 5a to 5c at each stage, the lower fire firing plate 1a and the upper fire firing plate 1b are ovens according to embodiments of the present invention described in detail below. The heating plate 1 is used.
FIG. 4 is a partial plan view of an oven heating plate according to an embodiment of the present invention. The heating plate 1 is made of a square and plate-shaped refractory brick, and through-holes 10 are formed in the wall thickness so as to be perpendicular to the thickness direction and dispersed in a plan view. The resistance heating body 11 is passed (inserted). Each resistance heating element 11 is sequentially connected by a connection lead portion 12 so that one heating plate 1 constitutes an independent heating means. However, each resistance heating body 11 can be implemented even if it connects so that several heating plates 1 may comprise one heating means.

In order to form holes in the heating plate 1 made of refractory brick as described above, for example, as illustrated in FIG. 5, when forming a brick molded body 1 ′ by kneading a brick material, the brick molded body is formed. A combustible bar (for example, a wood bar) 10a is embedded in a penetrating manner so as to be orthogonal to the 1 ′ thickness direction and dispersed in a plan view.
In this embodiment, each combustible bar 10a is disposed along and parallel to the width direction of the brick molded body 1 ′ having a square shape in plan view. Thus, it is desirable to arrange the combustible bars 10a so as to be parallel to each other.
Next, the brick molded body 1 ′ is supplied into a firing furnace and fired. At the time of firing, the combustible bar 10a is combusted, and the burned heating plate 1 has a combustion mark of the combustible bar 10a as shown in FIG. A hole 10 is formed in the hole. The oven heating plate 1 is manufactured by inserting the resistance heating element 11 into each hole 10.
The oven heating plate 1 can be used as a fired plate to be described later by inserting the resistance heater 11 through the holes 10 after the brick molded body 1 'is fired to form a refractory brick. Before or after inserting the resistance heating body 11 into each hole 10, the surface to be the heating surface can be polished.
Each hole 10 of the heating plate 1 is preferably linear so that it can be easily passed when the resistance heating body 11 is passed, but may be bent as long as it can pass the resistance heating body 11.

The raw material of the brick molded body 1 'in FIG. 5 (the refractory brick constituting the main body of the heating plate 1) is the same as that of a normal refractory brick. For example, aluminum oxide or silicon carbide is used as the main raw material, and silica or the like is used as necessary. Add an appropriate amount.
The following production conditions are preferable in order to form a thin film as much as possible and to have fire resistance, compression (bending) strength, thermal conductivity, and thermal expansion coefficient necessary as a material constituting the baking furnace of the oven.
For example, a small amount of binder is added to aluminum oxide 50 to 66 wt%, silicon carbide 25 to 35 wt%, and silica 5 to 11 wt% to make the whole 100 wt%, and firing is performed at an average of 1200 to 1500 ° C.
In such a raw material structure and manufacturing conditions, compression (bending) strength: 105 MPa or more, thermal conductivity: 3.9 W / m · K (at 600 ° C.) or more, thermal expansion coefficient: 0.55% (at 1000 ° C.) or lower heating plate 1 can be manufactured.

The manufacturing conditions including the raw material composition of the oven heating plate 1 of this embodiment are as follows.
Raw material component: Aluminum oxide 58.0wt%
Silicon carbide 30.0wt%
Silica 8.0wt%
Iron oxide 2.0wt%
Calcium oxide 2.0wt%
Firing temperature: 1300 ° C
Product thickness: 40mm
Distance from heating surface (upper surface of heating plate 1 in FIG. 6) to the center of hole 10: 15 mm
Diameter of hole 10: 9 mm
The above products have compressive strength: 112.0 MPa, thermal conductivity: 4.07 W / m · K (at 600 ° C.), 4.65 W / m · K (at 1000 ° C.), thermal expansion coefficient: 0.55 % (At 1000 ° C.).
In FIG. 6, the interval (pitch) between the holes 10 is small at the right end because the oven heating plate is a firing plate for installation on the opening side of the firing furnace.

Embodiment of Firing Furnace With reference to FIGS. 2 and 3, the firing furnace 5a using the oven heating plate 1 will be described in detail below.
Reference numerals 40 are, for example, angled-section pillars installed on the side of the firing furnace 5a, and the support members 4 having an angled section, for example, extend horizontally to the depth method on the pillars 40 at the same level. It is fixed (for example, screwed).
On each support member 4, a lower fire firing plate 1 a made of the heating plate 1 described above is installed, and a plurality of refractory bricks arranged on both sides of the lower fire firing plate 1 a so as to come into contact with corresponding struts 40. Each side wall 2 is provided.
A back wall 3 made of a plurality of fireproof bricks arranged side by side is installed in the upper part on the back side of the lower fire firing plate 1a.
On each of the side walls 2 and the back wall 3, an upper fire firing plate 1 b made of the heating plate 1 is installed so as to cover the upper surface of the firing furnace 5 a.

In this embodiment, each side wall 2 and each back wall 3 are made of the same material as the oven heating plate 1 which is the upper and lower firing plates 1a and 1b (however, no hole for inserting the resistance heating element 11 is formed). It is composed of a plate-shaped refractory brick, and is thinner than the upper and lower fired plates 1a and 1b.
A plurality of upper and lower firing plates 1a and 1b are arranged side by side in the depth direction of the firing furnace 5a, and the lower heater firing plate 1a and the upper fire firing plate 1b are arranged in a predetermined interval in the width direction of the firing furnace 5a. It is installed along. In the heating plate 1 constituting the upper and lower fired plates 1a and 1b, each resistance heater 11 is disposed so as to be closer to the heating surface side than the center of the thickness of the fired plates 1a and 1b, and is shown in FIG. Thus, in the area | region near the opening part (right side of FIG. 3) 54 of the baking furnace 5a, it arrange | positions so that a space | interval may be denser than another part. Moreover, in the part near the opening part 54 of the baking furnace 5a, the arrangement | positioning space | interval (pitch) of the resistance heating body 11 is made relatively smaller in the upper fire baking board 1b than in the lower fire baking board 1a.

A steam generation tank 31 made of a metal (for example, stainless steel) tank is installed on the upper fire firing plate 1b, and when it is desired to increase the humidity in the firing furnace 5a, a sprayer (not shown) is placed in the steam generation tank 31. The water is sprayed to generate steam in the tank 31, and a necessary amount of steam is supplied into the furnace through the steam supply port 30 formed in the back wall 3 through the steam pipe 32. .
As shown in FIG. 3, a smoke exhaust port 20 is formed in one side wall 2, and smoke generated in the firing furnace 50 a is discharged through a duct or the like (not shown) through the smoke exhaust port 20. Yes. A mounting hole 21 is formed in the side wall 2, and a lamp (not shown) is installed in the mounting hole 21.

In the above embodiment, the heating plates 1 constituting the upper and lower firing plates 1a and 1b are automatically controlled so as to maintain the furnace temperature set by the control panel (FIG. 1), and supply of steam into the furnace. The lighting control is also performed in the same manner.
When an electric oven is used, depending on the type of the object to be fired, a wire net, a tray or other container can be placed on the lower fire firing plate 1a in order to place or put the object to be fired.
Since the structure of the other firing furnace 5b is also configured in the same manner as the first stage firing furnace 5a, description thereof is omitted.

According to the electric oven of the embodiment, the upper and lower firing plates 1a and 1b of the firing furnace are configured by the oven heating plate 1 as described above, and the heating plate 1 disperses the resistance heating body 11 in its thickness. The hearth is sufficiently robust because it is made up of a single piece of refractory bricks.
In addition, the upper and lower fired plates 1a and 1b are made of refractory bricks as described above, and have a furnace atmosphere of a stone pot structure by repeating heat radiation by electric heating and radiation of far infrared rays, and temperature control is easy. Moreover, a wide variety of objects to be fired can be fired.

The upper and lower fired plates 1a and 1b are placed so that the resistance heaters 11 extend in the width direction of the firing furnace 5a, and each resistance heater 11 is disposed so as to approach the heating surface side of the fired plates 1a and 1b. Therefore, even if each fired board 1a, 1b is thick, the heat-transfer efficiency is high. Thus, even if it arrange | positions the resistance heating body 11 close to the heating surface of the baking boards 1a and 1b, since each heating plate 1 which comprises them is not what was joined by 2 sheets but is an integral fire brick, The heating surface is not greatly weakened.
Moreover, the installation interval of the resistance heating bodies 11 of the upper and lower fired plates 1a and 1b is closer to that in the region near the opening 54 of the firing furnace 5a than the other portions, and more than the lower fired fired plate 1a. The upper-fired fired plate 1b is set to be denser, and the amount of heating in the region near the opening 54 where the temperature tends to decrease due to the structure of the firing furnace 5a becomes relatively large, and the temperature control in the furnace Becomes easier.

  Since the firing ovens 5a and 5b of the electric oven of the above embodiment have a stone pot structure, the resistance heating body can be used as a stone pot without using the eleven. That is, without energizing the resistance heating body 11, after burning soot and gas in the furnace and heating the inside of the furnace to a desired temperature, the soot ash, scum or gas combustion burner is taken out, and the remaining heat in the furnace The object to be fired is fired using

It is a front view which shows one Embodiment of the electric oven which concerns on this invention. It is an expanded sectional view which expands and shows one baking furnace (The exterior decorative board, the driver, the heat insulation layer arrange | positioned inside a driver, and the door of an opening part are abbreviate | omitted) of the electric oven of FIG. . It is a fragmentary sectional view which follows the arrow AA of the baking furnace of FIG. It is a partial top view which shows one Embodiment of the heating plate for ovens which concerns on this invention. It is a fragmentary sectional view of the brick molded object before baking the heat-resistant brick which is the main body of the heating plate for ovens. It is a fragmentary sectional view of the heating plate of the state baked from the state of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oven heating plate 1 'Brick molded body 10 Hole 11 Resistance heating body 12 Connection lead part 1a Lower fire firing plate 1b Upper fire firing plate 2 Side wall 20 Smoke outlet 21 Mounting hole 3 Back wall 30 Steam supply port 31 Steam generation tank 32 Steam pipe 4 Support member 40 Post 5 Electric ovens 5a, 5b, 5c First stage to third stage furnaces 50 Door 51 Viewing window 52 Handle 53 Control panel 54 Opening of furnace

Claims (5)

The combustible bar (10a) is embedded in a penetrating manner so as to be orthogonal to the thickness direction and dispersed in a plan view before forming the brick, and the combustible bar (10a) is burned during firing to form holes (10 ), And made of refractory bricks through which the resistance heaters (11) are passed through the holes (10). The oven heating plate according to claim 1, wherein the hole (10) is disposed close to one surface of the refractory brick. The lower-fire firing plate (1a) and the upper-fire firing plate (1b) of the firing furnace (5a) are constituted by one or a plurality of oven heating plates (1) according to claim 1 or 2. An electric oven characterized by that. The electric oven according to claim 3, wherein both side walls (2) and the back wall (3) of the firing furnace (5a) are made of refractory bricks. The oven heating plate (1) constituting the lower-fire firing plate (1a) and the upper-fire firing plate (1b) of the firing furnace (5a) has the resistance heating element (11) of the firing furnace (5a). It arrange | positions in the state along a width direction, The said resistance heating body (11) is arrange | positioned in the area | region close | similar to the opening part (54) of a baking furnace (5a) at a space | interval denser than another area | region. Electric oven as described in.

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