JPH07258750A - Fluidized bed patenting heat treatment device and method using the same - Google Patents

Abstract

PURPOSE:To prevent the flow-out of sand for fluidized medium by providing conical introducing guide parts having a specific taper on the inlet side and the outlet side of the introducing pipes for guiding a steel wire to be heat treated and arranging plural gas nozzles at the bending edge parts in the inside of the guide part while directing a fluidized bed body. CONSTITUTION:The introducing pipes 4 for guiding the steel wire 3 to be heat treated into sand 5 in a chamber 7 are provided on the inlet side and the outlet side of the fluidized bed patenting heat treatment device. The conical introducing guide part 9 having 30-40 deg. taper is arranged in each introducing pipe 4, and the gas nozzles 1 are arranged in the plural positions at the bending edge parts in the inside of the guide part 9 while directing the fluidized bed body. The fluidized sand 5 piled on a dispersing plate 6 is fluidized and floated up by feeding pressurized gas 8 into the chamber 7 and the steel wire 3 to be heat treated, is guided with the introducing pipe 4 to execute the patenting treatment through the sand 5. At this time, the gas having 0.05-0.075kg/cm<2> pressure is spouted from the gas nozzles 1 arranged in the guide part 9 to prevent the flow-out of the sand 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for passing a steel wire in which heat treatment is performed in a continuous heat treatment line using a fluidized bed, and more particularly to prevention of outflow of sand which is a problem in the working environment.

[0002]

2. Description of the Related Art In the isothermal transformation heat treatment of steel wire, generally, patenting using lead is carried out. However, due to the recent trend of environmental improvement, in the small diameter, lead is being replaced by fluidized bed patenting. On the other hand, the sand used for the fluidized bed heat treatment is often made of zircon and alumina fine particles. In the fluidized bed heat treatment, the scattering of fine particles and the outflow during the heat treatment pose a problem in the working environment and also have a great influence on the running cost. Therefore, in the conventional technique, a method is used in which the outflowing sand is collected in a holding tank and the heat treatment furnace is replenished from the tank. However, with this method,
Installation of a replenishment tank and equipment for transporting from the replenishment tank to the heat treatment furnace were required, and there were problems in terms of equipment cost, running cost, and installation space. Further, since it is not possible to completely prevent scattering into the atmosphere, there is a problem that sand is accumulated around the equipment and the working environment is significantly damaged.

[0003]

DISCLOSURE OF THE INVENTION The present invention prevents the outflow of sand in such a fluid medium and makes it possible to secure a working environment.

[0004]

That is, the present invention has been made to solve the above-mentioned problems, and the gist of the present invention is to provide a continuous fluidized bed heat treatment apparatus having a horizontal pass line in the inlet side and Outlet guide tube taper angle 30
It is characterized in that a cone-shaped guide guide portion of -40 ° is provided, an inner curved edge portion is formed in the guide portion, and gas nozzles are installed at a plurality of positions of the edge portion so as to be oriented toward the fluidized bed main body. Fluidized bed patenting heat treatment equipment and fluidized bed patenting heat treatment equipment and fluidized bed patenting characterized in that the guide tube guiding portion in the equipment has a quadrangular pyramid shape and four gas nozzles are installed at the edges. In the heat treatment apparatus, a fluidized bed patenting heat treatment method characterized in that gas is injected at a pressure of 0.05 to 0.075 kg / cm ² from a gas nozzle provided in the guide portion of the induction pipe to prevent sand from flowing out. It is in.

[0005]

OPERATION AND EXAMPLES FIG. 1 shows the entrance side of the heat-treated steel wire of the device of the present invention. Note that the outlet side has the same configuration. 2 shows the details of the guide portion, but FIG. 2a is a side view and FIG. 2b is a front view thereof. In the fluidized bed patenting heat treatment apparatus, the guide tubes 4 for guiding the steel wire 3 to be heat treated are installed on the inlet side and the outlet side of the heat treatment apparatus. Each of the guide tubes 4 has a taper angle of 30-40.
Is provided with a cone-shaped guide guide portion 4 having an angle of 10 °, and an inner curved edge portion 10 is formed in the guide portion.
Is installed so as to face the fluidized bed body. The guide tube guide portion 9 preferably has a shape of a quadrangular pyramid, and the edge portion 10
It is preferable that four gas nozzles 1 are installed in the vertical and horizontal directions so as to surround the steel wire 3 to be heat treated. The pressure-fed gas 8 (air or nitrogen gas) sent into the chamber 7 in the present apparatus having such a configuration causes the fluidized bed sand 5 deposited on the dispersion plate 6 to flow and float. On the other hand, the heat-treated steel wire 3 is guided by the guide tube 4, passes through the sand 5 in which the fluid is suspended, and is patented. In addition, 2 shows a sand line during a normal heat treatment.

In the case of continuous fluidized bed heat treatment, stable heat treatment cannot be performed unless the sand line 2 during heat treatment is higher than the pass line through which the steel wire 3 to be heat treated passes. Therefore, when the guide pipe guide portion does not have the gas injection nozzle 1, sand flows out from the end portion of the guide pipe 4. For this reason, the sand level changes during the heat treatment, and finally the height decreases to the vicinity of the pass line, which causes variations in the heat treatment. In order to prevent this, the present inventor has studied systematic preventive measures, and as a result, found that the gas injection nozzle in the guide tube guide section is effective.

The present invention will be described in detail below. The guide portion and the edge portion attached to the end portion of the guide pipe are for efficiently blowing gas from the end portion of the guide pipe in order to push back the sand flowing out from the guide pipe. If the taper of the guide portion is too small, the sand inside the guide tube will be pushed back into the heat treatment apparatus depending on the pressure of the gas to be ejected. As a result, the temperature inside the heat treatment drops, making it difficult to secure a predetermined heat treatment atmosphere temperature. On the contrary, if the taper is too large, turbulent flow is generated in the jetted gas, and the sand is scattered from the outlet of the end portion, so that the outflow preventing effect cannot be expected. From the above, the taper part attached to the end of the guide tube is 3
0 ° to 40 ° is desirable.

Further, the shape of the guide portion is not particularly limited, but it is desirable that the ejected gas has a quadrangular pyramid shape in which turbulent flow is less likely to occur, and the number of gas ejection nozzles at that time is, for example, There is a high possibility that a turbulent flow will be generated with only two, or two on the left and right, and four gas injection nozzles are desirable. Furthermore, the mounting angle of the nozzle is
From the viewpoint of preventing turbulence, it is desirable to mount it at a right angle to the bottom surface of the square pyramid.

Next, the gas injection pressure will be described. If the gas injection pressure is too low, there is no sand outflow prevention effect, and if the pressure is too high, the sand in the induction tube is pushed out to the heat treatment furnace side, making temperature control in the heat treatment furnace unstable and stable. It becomes difficult to perform the heat treatment. From the above, the injection gas pressure is 0.05 to 0.075.
kg / cm ² is desirable.

(Example) A wire of 5.5 mm was drawn into a steel wire of 1.8 mm by wire drawing, and then a fluidized bed heat treatment was performed. The austenitizing temperature was constant at 950 ° C. and the heating time was 60 seconds. The heat treatment temperature was kept constant at 540 ° C. The fluidized bed medium used was alumina sand (# 120).
It was used. The amount of sand flowing out during the heat treatment was measured by setting a pan directly below the end of the guide tube and accumulating in the pan.

[0011]

[Table 1]

Examples are shown in Table 1. Nos. 1 to 8 are the method of the present invention. No. 9 to 16 are shown as comparative methods. Comparison method N
In Nos. 9 to 11, the taper angle is deviated from that of the method of the present invention, and thus the sand flows out a lot. In Nos. 12 and 13, since the number of nozzles is small, the outflow of sand is large. No14, 1
In No. 5, the injection pressure of the air nozzle exceeds the limit range of the method of the present invention. For this reason, sand often flows out. Also, No1
6 is the level without taper and air nozzle,
Most sand flows out. On the other hand, Nos. 1 to 8 of the present invention method
Is 0.11 / hr, and it can be seen that the effect is great for preventing sand outflow. These show that the effect of preventing the outflow of sand appears only after the proper taper angle, the proper injection pressure of the air nozzle, and the proper nozzle arrangement.

[0013]

INDUSTRIAL APPLICABILITY According to the present invention, sand can be prevented from flowing out in the continuous fluidized bed heat treatment, stable heat treatment can be performed, and its effect can be exerted for safety and maintenance of working environment.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a sand outflow device of the present invention.

FIG. 2 is a diagram showing details of a guide unit.

[Explanation of symbols]

 1 gas nozzle 2 sand line during heat treatment 3 steel wire to be heat-treated 4 induction pipe 5 sand for fluidized bed 6 dispersion plate 7 chamber chamber 8 pumped gas 9 induction guide part 10 edge part

Claims (3)

[Claims] 1. A continuous type fluidized bed heat treatment apparatus having a horizontal pass line, wherein the inlet side and outlet side guide pipes are provided with cone-shaped guide guides having a taper angle of 30 to 40 °, and the guides are bent inward. The fluidized bed patenting heat treatment apparatus is characterized in that the gas nozzles are formed at a plurality of locations on the edges and the gas nozzles are oriented toward the fluidized bed body. 2. The fluidized bed patenting heat treatment apparatus according to claim 1, wherein the guide tube guide portion has a shape of a quadrangular pyramid, and four gas nozzles are installed at an edge portion. 3. The fluidized bed patenting heat treatment apparatus according to claim 1 or 2, wherein the pressure is 0.05 to 0.075 kg / c from a gas nozzle provided in the guide tube guide portion.
A fluidized bed patenting heat treatment method characterized in that a gas is sprayed in a range of m ² to prevent sand from flowing out.