JPS5825416A - Electric heating furnace - Google Patents

Abstract

PURPOSE:To uniformly heat a long-sized substance to be heated, in the upper and lower directions without a temperature difference, by providing an inside cylinder which has stored the substance to be heated, in the longitudinal direction, in a vertical type cylindrical heating furnace, and making a hot blast in the furnace circulate to the inside and the outside of the inside cylinder by use of a fan. CONSTITUTION:In a vertical type electric heating furnace formed by assembling a cylindrical unit furnace body 1 by a blange 15 and flange receivers 16, 23 on a bottom plate 2, the outside cylinder is formed by providing a heat resisting layer 12 to which a plurality of heaters 13 have been installed with a supporting piece 14, on the inside surface of an outside plate 11, and on its upper part, a cover body is installed. Into said outside cylinder, an inside cylinder 4 is inserted in the longitudinal direction at a suitable interval, and on its upper and lower ends, ventilation gaps 41, 42 are provided. In this state, a substance to be heated 6 is heated by storing the substance to be heated into the inside cylinder 4 by a supporting arm 44, etc., heating the inside of the furnace by the heater 13, rotating a centrifugal fan 35 by a motor 34 through a rotary shaft 33, and making hog blast in the inside and the outside of the inside cylinder 4 circulate in the direction as indicated with an arrow.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a heating furnace used for hardening, annealing, etc., and is particularly designed to effectively heat long objects.

Conventionally, in this type of heating furnace, the object to be heated is housed in an outer frame lined with heat-resistant material and heated directly by a heater, and in the case of long objects, the temperature difference between each part, especially the top and bottom, is minimized. Therefore, it is supported at the 111 position. For this reason, it tends to warp due to heating.

The support device inside the furnace becomes cumbersome, and the furnace becomes horizontally long, requiring a large installation space.

In view of these points, the present invention has made the heating furnace vertical so that the object to be heated can be supported vertically, and in order to eliminate the temperature difference between the upper and lower parts of the furnace, which is now vertically long, a wall is provided inside the furnace to direct the heating air. An embodiment shown in the figure will be described below.

/ is a cylindrical unit furnace body, and a heat-resistant layer /2 such as silica board or ceramic fiber is provided on the inner surface of the outer plate //.
It is on the inner peripheral surface t of this heat-resistant layer that the heater 3 is installed by means of a large number of support pieces 1.

15 is the 7 langes attached to the lower part of the outer panel //, /B is the flange receiver installed on the upper part of the outer shell, /7 is the reinforcing plate, /I
is the terminal box, / is the protective ring of the heat-resistant layer. 2 is the bottom plate, which is covered with an outer plate 2/inner refractory brick 2, and the outer plate 2/l has a flange receiver 1 similar to the flange receiver 6 above. It has 3. 3 is a lid body with 7 langes 32 at the bottom of the outer plate 3/ filled with r# thermal material, and a rotating shaft 3 in the center.
3, and the upper end of this rotating shaft 33 is connected to the drive motor 3.
Connect q.

A centrifugal fan 3S is attached to the bottom end. 3B is a heat exhaust hole, and 37 is a cover of the heat exhaust hole, which is opened and closed by the power cylinder 3g.

1 strain the inner cylinder so that it can be divided into t parts as needed,
A ventilation gap of l/·12 is provided between the lower end and the bottom plate and between the upper end and the lid.

Reference numeral II3 denotes a support leg, l denotes an arm for supporting the heated object attached to the inner cylinder, and 5 denotes a cooling vibrator for cooling the inside of the furnace after heating, and an exhaust pipe 5/5 is arranged in an annular shape below the inner cylinder. This exhaust pipe is equipped with an air supply pipe S2 that sends cooling air.

B is the object to be heated.

Fit the 7 langes 15 of the unit furnace body onto the flange receiver 23 of the bottom plate covered with firebrick 2, and place the 7 langes 15 on the flange receiver 23 of the bottom plate. ; are fitted and stacked, and the inner cylinder L is inserted vertically into this furnace, and the object to be heated is inserted into the inner cylinder L in the vertical direction, and the supporting arm p+ is used to insert it from 3 or 1 sides. Press and support.

The lid body 3 is placed by fitting the seventh flange 32 with the flange receiver of the furnace body. In addition, it is desirable to interpose a heat-resistant packing in each connection polymerization part.

When the heaters 3 of each unit furnace body are connected in parallel or in series to the power supply and the temperature inside the furnace rises, the drive motor 31I rotates the fan 35 via the rotating shaft 33, causing the air in the inner cylinder to rise. The air is blown out from the ventilation gap 12 into the annular space t outside the inner cylinder l, and is circulated from the ventilation gap ll/ at the bottom of the inner cylinder into the inner cylinder q as shown by the arrow, and during this period the circulating air is heated by the heater 3. Due to this hot air, there is almost no temperature difference between the top and bottom inside the inner cylinder.For example, when the temperature inside the furnace is 1.000, the temperature difference between the top and bottom is maintained at /~2C, and the object to be heated is heated uniformly. .

(5) Note that the hot air circulation path may be directed in the opposite direction.

If the centrifugal fan is used as in the example, the air that heats and rises within one cylinder is sent out to the outer circumference, so hot air is not blown directly onto the object to be heated, there is little temperature difference between the top and bottom, and circulation is smooth. There are some advantages.

When lowering the temperature inside the furnace, operate the power cylinder 3g to open the lid 37 of the heat exhaust hole 3B of the lid body 3, and introduce outside air from the cooling vibe S at the bottom of the cylinder 9 to the exhaust pipe 5/ (not shown). It is ejected into the furnace through the hole.

In this way, one aspect of the present invention is to provide a heating furnace with an inner cylinder provided vertically with ventilation gaps, store the object to be heated in the inner cylinder, and use a fan at the top of the inner cylinder to blow hot air inside the furnace. The temperature difference between the top and bottom of the furnace is almost the same even though the inside of the furnace is vertically long. Also for heated objects.

Since it is supported vertically, no deflection occurs due to heating.
It is effective, and the installation space for the furnace body is also reduced.

This has the advantage of being able to effectively ventilate the inside of the furnace during cooling.

(B) Furthermore, if one or both of the outer cylinder and the inner cylinder is divided into a plurality of parts and stacked vertically, manufacturing is simple, and transportation and assembly are also easy.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a top view of the lid, and FIG. 3 is a top view of the unit furnace body. / is a unit furnace body, 2 is a bottom plate, 3 is a lid body, l is an inner cylinder. 5 is the cooling vibrator, B is the object to be heated, // is the outer plate. /2 is a heat-resistant layer, /3 is a heater, /3 is a flange. /Otsu・23 has 7 lunge receivers, and 3 are drive motors. 35 is a fan, 3 O is a heat exhaust hole, and l1l-112 is a ventilation gap.

Claims (1)

[Scope of Claims] 1. An outer cylinder provided with a heat-resistant layer on its inner surface and equipped with a heater on the inner peripheral surface of the heat layer, and a bottom plate at the bottom of the outer cylinder. A lid body at the top of the outer cylinder, an inner cylinder inserted vertically into the outer cylinder at an appropriate interval and provided with ventilation gaps at the lower and upper ends, and a fan provided at the upper part of the inner cylinder. An electric heating furnace characterized in that an object to be heated stored in the inner cylinder with a ventilation gap is heated by heated air circulating inside and outside the inner cylinder. 2. Claim 1, wherein the fan is a centrifugal fan.
Electric heating furnace as described in section. 3. The electric heating furnace according to claim 7, wherein the outer cylinder or the inner cylinder vertically stacks and connects a plurality of unit furnace bodies.