JPS5848610B2 - Nozzle control device for high-speed jet industrial preheating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nozzle control device for a high-speed jet industrial preheating device, in which the distance between a material to be heated and an injection nozzle that injects preheating gas to the material to be heated is controlled by the gas injection speed. Alternatively, it is automatically adjusted in response to changes in the thickness of the material to be heated.

Conventionally, in an industrial furnace, for example, a continuous heating furnace 1 as shown in FIG. Injection is carried out on the upper and lower surfaces of 6.

The purpose of the injection is to peel off the boundary layer on the surface of the heated material 6 to obtain a high heat transfer coefficient.

The above combustion exhaust gas changes in quantity as the load on the furnace changes, and therefore the gas injection speed from the injection nozzle 5 also changes accordingly.

The distance between the injection nozzle 5 and the heated material 6 as shown in FIG.
1, when the heat transfer coefficient is α, both are different at various gas injection speeds U. ! 9, it has been confirmed that there is a relationship as shown in FIG.

As can be seen from this, the relationship between H, α, and Ul is satisfied at each point on the curve S, but since this is fixed in the conventional injection nozzle 5, the relationship between the injection nozzle 5 and the heated The distance H between the material 6 and the heated material 6 is always kept constant (for heated materials of the same thickness), and the optimum heat transfer coefficient is always obtained even when the gas injection speed changes due to fluctuations in the amount of combustion exhaust gas generated. I can't.

This invention provides a nozzle control mechanism that automatically responds to fluctuations in gas injection speed and always ensures an optimal heat transfer coefficient. The configuration includes a preheating gas injection nozzle that can be adjusted at an interval relative to the material to be heated, and includes a pressure detector that detects the pressure of the preheating gas, and a pressure signal from this pressure sensor that is used to inject the gas from the injection nozzle. A computing unit that converts into speed or flow rate and determines the optimum spacing between the injection nozzle and the heated material based on the converted value, and drives the injection nozzle to the optimum spacing state based on the output signal of this computing unit. The present invention is equipped with a nozzle drive device.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

Reference numeral 7 denotes a header installed under the furnace ceiling wall 8, and a predetermined number of injection nozzles 9 are fitted into the header 7 facing downward and movable up and down.

Since each injection nozzle 9 penetrates the header 7 vertically, a seal box 11 equipped with a sealing material 10 is provided at each nozzle penetrating portion of the header 7, and each injection nozzle 9 is provided with a seal box 11 provided with a sealing material 10. An inlet 12 is provided that opens inside.

13 is a nozzle drive device, and a hydraulic servo mechanism 14
and an interlocking mechanism 15 for synchronously driving each injection nozzle 9.

16 is a pressure detector, 17 is a gas pressure outlet from the header 7, 18 is a first computing unit, 19 is a second computing unit, 20 is a setting unit, and 21 is a heated material.

In the above configuration, the pressure P of the preheating gas (for example, the combustion exhaust gas as described at the beginning) passing through the header 7 is detected by the pressure detector 16.

The pressure signal from the detector 16 is converted into a gas injection velocity Ug from the injection nozzle 9 in the first computing unit 18 .

The relational expression in this case is given by U,9-ξv''T.

However, ξ is a constant. The converted value from the first computing unit 18 is input to the second computing unit 19, and based on this converted value and the set value of the thickness of the material to be heated in the setting device 20, the second computing unit 19 determines whether the injection nozzle 9 or the heated material The distance H between the material 21 and the material 21 is determined to be the optimum distance corresponding to the gas injection speed tJ7.

The relational expression in this case is given by H-ξU7. The output signal of the second computing unit 19 enters the servo valve 22 of the servo mechanism 14 and drives the piston rod 24 of the servo cylinder 23, thereby rotating the lever 25 of the interlocking mechanism 15, that is, the interlocking shaft 26, and rotating each lever 27. The injection nozzles 9 are raised or lowered via the rods 28 to the optimum spacing.

The second computing unit 19 is based on the gas injection speed U,9, but the pressure signal to the first computing unit 18 is based on the gas flow rate Q.
It is also possible to use a device that operates based on this flow rate conversion value.

The above-described operation is also performed on the lower surface of the material to be heated 21 using a nozzle mechanism (not shown) similar to that described above.

The above-mentioned interval adjustment can also be performed by moving the nozzle tip up and down if the injection nozzle 9 is equipped with a movable nozzle tip (not shown).

As explained above, according to the present invention, the interval between the heated material and the injection nozzle is automatically adjusted to the optimum interval in response to fluctuations in the gas injection speed and thickness variations of the heated material.
Optimum heat transfer coefficient can always be ensured.

[Brief explanation of the drawing]

Fig. 1 is a front view showing one embodiment of the present invention, Fig. 2 is a view taken along the line A-A in Fig. 1, Fig. 3 is a vertical side view of a continuous heating furnace, and Fig. 4 is a conventional example. The front view and FIG. 5 are diagrams showing the relationship between H and α when U and 9 are constant. 7... Header 9... Injection nozzle,
13... Nozzle drive device, 14... Servo mechanism, 15... Interlocking mechanism, 16...
・Pressure detector, 18.19... Arithmetic unit, 21.
...Material to be heated.

Claims (1)

[Claims] 1 A configuration in which the injection nozzle for preheating gas to the heated material is provided so that the interval can be adjusted with respect to the heated material, and a pressure detector that detects the pressure of the preheating gas and a pressure signal from this pressure detector are installed. A calculation unit that converts the gas injection speed or flow rate from the injection nozzle and determines the optimum distance between the injection nozzle and the heated material based on the converted value, and a calculation unit that converts the gas injection velocity or flow rate from the injection nozzle to determine the optimum distance between the injection nozzle and the heated material, and a calculation unit that operates the injection nozzle based on the output signal of this calculation unit. A nozzle control device in a high-speed jet type industrial preheating device, which is equipped with a nozzle drive device that drives the nozzles in an optimum interval state.