Device for discharging exhaust air from the surroundings of a metal strip

Abstract

A device for discharging exhaust air from the surroundings of a metal strip. The device has air quantity boosters with an opposing suction device on the other side of the conveying path in the blowing direction in order to suction and discharge the airflow generated by the air quantity boosters together with the exhaust air. In order to reduce costs for the operation of the device, a sensor device is provided in order to detect whether the metal strip is present or not and at which speed the metal strip is being moved. Additionally, a controller is provided in order to adjust the delivery rate of the air quantity boosters and the suction device depending on the measured speed.

Claims

1. A device for discharging exhaust air from surroundings of a metal strip, comprising: at least one blower arranged on one side of a conveying path of the metal strip, for generating an air flow for conveying the exhaust air in a blowing direction transversely with respect to the conveying path, where an the blower is configured as at least one air quantity booster; an extraction device arranged opposite the blower in the blowing direction on the other side of the conveying path for extracting and discharging the air flow with the exhaust air, which air flow is generated by the blower; a sensor device that detects whether the metal strip is present and, when the metal strip is present, measures a speed at which the metal strip moves; and a control device for deactivating the air quantity booster and the extraction device when the metal strip is not present and for setting a delivery capacity of the air quantity booster and the extraction device in a manner dependent on the presence and the measured speed of the metal strip.

2. The device according to claim 1, wherein the control device is configured to increase the delivery capacity of the air quantity booster and the extraction device when an increase in the speed of the metal strip is measured and to decrease the delivery capacity of the air quantity booster and the extraction device when a decrease in the speed of the metal strip is measured.

3. The device according to claim 1, wherein the control device is configured to switch off the air quantity booster and the extraction device when the measured speed of the metal strip undershoots a predefined speed threshold value.

4. The device as claimed in claim 1, further comprising an exhaust air treatment system connected downstream of the extraction device for purifying the exhaust air sucked in by the extraction device.

5. A roll train, comprising: at least one first rolling stand and at least one second rolling stand arranged behind one another in a rolling direction for rolling a metal strip; and a device arranged between the first rolling stand and the second rolling stand, the device including: air quantity boosters arranged on one side of a conveying path, along which the metal strip is conveyed between the rolling stands, and being oriented to have a blowing direction directed transversely with respect to the rolling direction over the conveying path of the metal strip, an extraction device arranged on a side of the conveying path which lies opposite the air quantity boosters in the blowing direction, a sensor device that detects whether the metal strip is present and, when the metal strip is present, measures a speed at which the metal strip moves, and a control device for deactivating the air quantity booster and the extraction device when the metal strip is not present and for setting a delivery capacity of the air quantity booster and the extraction device in a manner dependent on the presence and the measured speed of the metal strip.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Three figures are appended to the invention, in which:

(2) FIG. 1 shows the device according to the invention and the roll train according to the invention in a plan view,

(3) FIG. 2 shows the device according to the invention in a cross section transversely with respect to the transport direction, and

(4) FIG. 3 shows the device according to the invention in a cross section along the transport direction.

DETAILED DESCRIPTION OF THE INVENTION

(5) The invention will be described in detail in the following text in the form of exemplary embodiments with reference to the stated figures. Identical technical elements are denoted by identical designations in all figures.

(6) FIG. 1 shows the device 100 according to the invention for discharging exhaust air from the surroundings of a metal strip 200, installed between a first rolling stand 310 and a second rolling stand 320 of a roll train for rolling, preferably for cold rolling the metal strip 200. In accordance with the example according to FIG. 1, the device comprises a plurality of air quantity boosters 110 which are arranged opposite the extraction device. The blowers in each case generate an air flow (shown by way of the dashed lines in FIGS. 1 and 2) in a blowing direction BR transversely with respect to the transport direction WR of the metal strip 200. The air flow which is generated entrains exhaust air which is possibly situated in the surroundings of the metal strip, in the direction of the blowing direction BR. As viewed in the blowing direction BR, an extraction device 120 is situated on that side of the conveying section for the metal strip which lies opposite the air quantity boosters 110, for extracting and discharging the air flow with the exhaust air, which air flow is generated by the air quantity boosters. A exhaust air treatment system 150 is preferably connected downstream of the extraction device 120, for purifying the exhaust air which is sucked in by the extraction device.

(7) Furthermore, the device according to FIG. 1 has a sensor device 130 on the inlet side of the first rolling stand 310, for detecting whether and at what speed the metal strip 200 is being moved. In response to the measured signal of the sensor device 130, a control device 140 activates the air quantity boosters 110 and the extraction device 120 if the signal of the sensor device 130 signals the presence and a preset or measured speed of the metal strip 200. Otherwise, that is to say if no metal strip 200 is detected or present or a predefined speed threshold value is undershot, the air quantity boosters 110 and the extraction device 120 are deactivated.

(8) In the present invention, the air molecules of the exhaust air are transported by way of the air flow which is generated by the air quantity boosters, that is to say with a directed flow over a relatively great distance, that is to say to the opening of the extraction device 120. The air molecules of the exhaust air can then be extracted with a substantially lower (air) volumetric flow and therefore with a substantially lower energy expenditure than if it would have to first of all be sucked in over a further distance as far as to the intake opening of the extraction device. The circumstance that air molecules can be blown substantially further than they can be sucked with the same energy input is decisive for this.

(9) Existing roll trains can advantageously be retrofitted simply and inexpensively by way of the claimed invention.

(10) FIG. 2 shows a cross section through the device 100 with a section transversely with respect to the transport direction WR of the metal strip.

(11) FIG. 3 shows a cross section through the roll train 300 and the device 100 with a section in the longitudinal direction of the metal strip and with a section in the transport direction WR of the metal strip, respectively. 100 Device 110 Air quantity booster 120 Extraction device 130 Sensor device 140 Control device 150 Exhaust air treatment system 200 Metal strip 300 Roll train 310 Rolling stand 320 Rolling stand BR Blowing direction WR Rolling direction