JPH0239193Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a continuous heating furnace.

[Conventional technology and its problems]

BACKGROUND ART Mesh conveyor type and pusher type continuous furnaces are commonly used as heating furnaces for brazing, sintering, firing, etc.

In such a heating furnace, the material to be processed is transferred under hot conditions, so metals (mesh belt,
This causes softening and transformation phenomena of the trays, objects to be treated), refractories (hearth plates), etc., and the mechanical strength including the heat resistance of metal parts decreases significantly. In order to improve belt wear and shorten the lifespan of refractories caused by these, conventionally, welded drainboards have been used, in which rail materials such as SUS materials, round bars, and pipes are vertically and horizontally assembled and welded inside the furnace core (matsufuru). Strategies were adopted such as interior decoration or adding grooves in the longitudinal direction to the hearth plate.

However, with the method of laying metal rail materials and slats, the rail materials and slats are irregularly deformed into waves due to high temperatures, and the mesh belt that slides on this material becomes severely abraded due to local loads, and the abrasion powder is transferred to the rails. It adheres to and accumulates on the surface of wood and drainboards, and becomes semi-molten and firmly adheres. This has caused a problem in that the mesh belt wears out and the belt life is shortened.

Moreover, when the rings and pins constituting the mesh belt get caught on the deposits and come off the deposits under the strong load of the driving force, an impactful movement occurs in the conveyor belt. For example, if the process is brazing, problems such as the brazing metal falling off from the brazed parts and no longer being joined at all, or the brazing parts becoming misaligned and being joined in an abnormal position can occur. The problem was that this occurred frequently and the defective rate increased.

In addition, if the hearth plate is not flat but has grooves, the coefficient of friction will increase due to the softening of the refractory material due to high temperatures, and the hearth plate will wear out because it rubs against the refractory material tray over a wide contact area at high temperatures. There was a serious problem in that repair and replacement required time and effort, resulting in high running costs.

[Means for solving problems]

This invention was devised through research to solve the above-mentioned problems, and its purpose is to reduce wear on the mesh belt and hearth plate, prolong their lifespan, and improve the performance of the belt. There is no abnormal movement of the mesh belt due to the accumulation or adhesion of abrasion powder or dust, and problems such as falling off of the brazing material or misalignment of brazed parts due to this, and smooth transfer heating can be performed for a long period of time.Moreover, the structure is simple and inexpensive. The object of the present invention is to provide a bottom structure for continuous heating that can be easily performed and maintained.

In order to achieve this objective, the present invention is a furnace in which a large number of ceramic balls are spread on the hearth surface that slides on the objects to be processed, the trays containing them, or the conveyor belt on which these are placed and moved. The floor surface is the inner bottom of the furnace core tube in the case of a belt conveyor furnace, and the hearth surface in the case of a pusher furnace.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figures 1 to 3 show an embodiment in which the present invention is applied to a mesh belt conveyor type heating furnace, in which 1 is a furnace body made of refractory material and having a heating zone 11 inside thereof; The furnace core tube 12 is attached to the inside of the furnace body 1, and the front tube (preheating section) 2 is connected through flanges 120, 120 at both ends protruding from the longitudinal direction of the furnace body 1.
and the rear cylinder (cooling section) 3 are connected.

4 is an endless mesh conveyor belt, and pulleys 5,
The object to be treated or the tray containing the object is sequentially transferred from the front tube 2 to the furnace main body 1 to the rear tube 3.

Balls 6 are made of ceramic material such as alumina, silicon carbide, nitrogen, zirconia, and light, and are spread on the inner bottom surface of the furnace core tube 12 so as to be able to rotate on their own axis. Partition plates 7, 7 whose height is lower than the diameter of the sphere are provided.

Note that the inner bottom surface 121 of the furnace core tube 2 does not necessarily have to be flat, and may have a groove in the longitudinal direction, and in this case, the ceramic balls 6 may be placed in the groove.

Figures 4 to 6 show an embodiment in which the present invention is applied to a pusher type heating furnace, in which a front cylinder 2' and a rear cylinder 3' made of refractories are installed in front and behind a furnace body 10 made of refractories. They are connected in series, and a pusher 10 is disposed on the inlet side of the front cylinder 2', and continuously feeds the tray containing the material to be treated into the front cylinder 2'. It is designed to heat and then cool the liquid.

A hearth member 13 constitutes the inner bottom of the furnace body 1, front cylinder 2', and rear cylinder 3', and is made of a refractory material such as silicon carbide. Either a concave surface 15 surrounded by a protruding wall 14 is formed as shown in FIG. , 15' and their concave surfaces 15, 1
Ceramic balls 6 having a diameter larger than the height of the protruding walls 14, 14' are spread over the wall 5'.

Figures 6a, b, and c show embodiments of the groove-like concave surfaces 15' and 15'. Figure 6a shows an example in which the groove cross section is square, and Figure 6b shows the bottom area of the groove cross section. FIG. 6c shows one in which the groove cross section has edges 150, 150 projecting inward at the upper end. The hearth member 13 may be divided into segments each having a required length.

[Effect of the embodiment]

In the present invention, as described above, the ceramic balls 6 are spread over the hearth surface on which the object to be processed, the tray containing the object, or the conveyor belt slides.
Frictional resistance is extremely small because the contact area with the moving object is small, the ball itself has a small friction coefficient, and it rotates by sliding relative to the moving object. Moreover, due to its material and shape characteristics, it has high hardness, excellent wear resistance, and high mechanical strength such as compressive strength.
It has high heat resistance, excellent high temperature stability and electrical insulation.

As a result, the generation of abrasion particles that is seen with metal rails or the combination of drainboards and mesh belts is significantly reduced, and the movement of the conveyor belt is extremely smooth because there is no accumulation or fusion of abrasion particles. This prevents the brazing filler metal from falling off and brazing parts from shifting during movement in the furnace. Therefore, the defect rate in the brazing process is extremely reduced, and brazed products with excellent precision and quality can be obtained with a high yield.

In addition, even if worn particles from the belt or dust attached to the belt and brought into the furnace fall from the conveyor belt, the ceramic balls 6 rotate and automatically remove the dust. Since the ceramic balls 6 are allowed to flow downward and stored in the gaps between the ceramic balls 6, 6, no local load is applied to the conveyor belt.

Moreover, since the ceramic balls 6 are spread all over, construction is easy, and there is no need for major modification of the furnace core tube, and it can be easily applied to an existing heating furnace, making maintenance easy.

The present inventor considered the application of ceramic rolls, but the structure itself is complicated, and a bearing part etc. must be machined on the furnace core tube.Moreover, the rotation is directional, and wear particles etc. This is undesirable because it tends to cause problems such as localized loads being applied to the belt due to jamming, damage caused by bending loads applied to the roll cylinder or shaft end, and trouble and time required to repair the damage.

[Effect of idea]

According to the present invention described above, it is possible to extend the life of conveyor belts, trays, etc., and prevent abnormal movement of belts and trays caused by abrasion particles and dirt falling or accumulating on the sliding zone. It does not cause misalignment of the objects to be processed, allows smooth transfer and heating over a long period of time, improves the yield of good products, and has a simple structure, can be implemented at low cost, and is easy to maintain. Excellent results can be obtained.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional side view showing one implementation side of a continuous heating furnace according to the present invention, FIG. 2 is an enlarged view of the furnace core tube portion in FIG. 1, and FIG. 3 is a partially cutaway perspective view thereof. Fig. 4 is a partially cutaway plan view showing another embodiment of the present invention, Figs. 5 a and b are perspective views of the hearth portion in Fig. 4, and Figs. It is a partial perspective view showing an example of arrangement in a type. 4... mesh conveyor belt, 6... ceramic ball, 7... partition, 13... hearth member.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a furnace that heats a workpiece while transporting it at a required speed, a ceramic material is installed on the floor surface of the furnace on which the workpiece, the tray containing the workpiece, or the conveyor belt slides. A continuous heating furnace characterized by being lined with balls. (2) The continuous heating furnace according to claim 1, wherein the furnace floor surface is the inner bottom of the furnace core tube. (3) The continuous heating furnace according to claim 1, wherein the furnace floor surface is a refractory surface.