DE1111326B - Electric multi-slide control, especially for blast furnace wind heaters - Google Patents

Description

Electric multi-slide control, especially for blast furnace wind heaters The invention relates to an electrical multi-slide control, in particular for Blast furnace heater, for the positive actuation of the movement of the slide in the sequence dictated by operation, with each slide a limit switch which switches the drives of the slide and triggers the switching, whereby the operating positions "wind" and "gas" can be set using a selector switch. The object of the invention is the operational sequence of the slide movements with as few switching elements as possible with maximum operational safety and with disconnection possible operating errors.

The operation of multi-slide controls, especially with blast furnace hot air heaters, requires special safety devices, and it is also necessary that both a prescribed program of the individual slide runs automatically as well as an individual actuation of each slide without influencing the others Slide with the simplest structure of all control circuits for the slide is possible. Furthermore, it is absolutely necessary for the smooth workflow to be susceptible to failure of the entire system to a minimum.

The previously known multi-slide controls meet these requirements Requirements do not. For example, a controller is known in which the two Operating positions "wind" and "gas" achieved by means of a reversing switch that the current direction when switching from "wind" to "gas" or vice versa is changed. Thereby the drives of the slide are in the by the enterprise conditional order switched.

The disadvantage of this circuit, however, is that during the process the closing and opening movements of the slides are not possible, in the event of a malfunction (inhibition of running) or in special cases, for example after repair work Carry out test runs, the slides individually, without influencing the others, to operate. Cattle had to have more when disturbances occurred as a result of an inhibition to run in the case of the slides, these are operated in opposite directions by hand using cranks or winches will.

To avoid this disadvantage, it is already known in a Device in which after switching a certain main switch (gas-wind) manually adjust the positions of the following slides or groups of slides through the Movement of the preceding can be reversed automatically, in addition to each slide or each slide group is assigned a special switching element via which in the inevitable process can be intervened. However, there are known at this one Device in the case of such an engagement at least two not with each other to operate coupled switching devices. This fact excludes a certain element of uncertainty and thus represents a source of danger that cannot be overlooked.

Another disadvantage is the fact that the slide after Disconnection of the drives by limit switches, uncontrollable overtravel or return can carry out the impact of the impacts on the boundaries Slide plates are triggered. The slides can then under certain circumstances such take up a position that creates a risk of explosion. this can be the case, for example, when the hot blast valve as a result of a Return by impact assumes such a position that the hot blast path to Blast furnace is not locked, so that after opening the gas slide correctly in the program the hot wind penetrates the gas line due to its overpressure. This will if the mixture is mixed correctly, gas ignition is triggered, causing serious accidents Operational disruptions and property damage can result. Another serious one Malfunction can also occur if the flue gas valve as a result a return caused by impact does not block the flue gas pipe, so that after the heating season, when the wind is introduced into the cowper, after the heating has taken place, it partially makes its way through the furnace instead of to the blast furnace Flue gas pipe takes. In one that is still known A special main power switch is required in addition to the selector switch. This is an automatic circuit, after which either all slides necessarily without the possibility of intermediate positions one after the other on "gas" or "Wind" can be switched, whereby the process, once initiated, can no longer be stopped is; unless additional shutdown devices are provided for this device as well to interrupt the automatic process.

To in a device as described in more detail at the beginning, the To avoid the defects listed, the invention proposes the selector switch to be designed as a roller switch that switches between operating positions "wind" and "gas" Has intermediate positions in which the switching triggered by the limit switch the slide is in the corresponding intermediate position of the switch Step can be interrupted and reversed.

Sliding armature motors known per se can be used as drives for the slides Use it, or it can be between a normal electric motor and the slider a self-locking gear can be provided. In both cases, however, the Slide immediately immovable after the drives have been switched off by the limit switch held.

The functional sequence of the control is explained in more detail on the basis of the drawing explained.

Fig. 1 shows schematically the main flow picture with a cowper and the associated shut-off devices; Fig. 2 shows the selector switch in connection with the Control current diagram.

The starting position for the description is the working position on »wind«. In this position the selector switch A is set to 1, the contacts W 1 to W 5 being closed and the contacts G 1 to G5 being opened, ie the slides 5, 4, 3 are closed and the slides 1, 2 are open. The associated limit switches El, E2 of slide 1 # 2 have taken the "open" position and switched off the drives for the slide and at the same time initiated the sequential switching.

The associated limit switches E3, E4, E 5 of slides 3, 4, 5 have taken the "closed" position and also switched off the drives for the slides and triggered the subsequent switching.

If you want to switch from the "wind" position to "gas", there are basically two options. Either you go step by step from position I to position V, whereby the slide runs are only triggered after inserting the selector switch into the corresponding intermediate positions, or you can immediately set from position I to position V via the intermediate positions 1I, as, 111 and IV so that the slide runs follow one another without a break.

When changing from position 1 to position 1I, the selector switch contacts remain W 5 to W 2 are closed, W 1 is opened and G 1 is closed. This will once the contact ela is separated from the voltage and, on the other hand, the contact elz is connected to voltage placed, whereby the reversing contactor 1z energized and the drive for the slide 1 switched on will. When the slide 1 has reached the closed position, it becomes the limit switch E 1 actuates and thereby de-energizes the contactor l z, whereby the drive for the slide 1 is stopped. At the same time, voltage is applied through elz G2 and also prepared the excitation of contactor 2z by e2z. In this position slide 1, 2, 4, 5 are closed, slide 2 is open.

By switching the selector switch A from position 1I to as, G2 is closed and the reversing contactor 2z is excited via e2z, whereby the drive for the slide 2 is switched on. When G 2 was closed, W 2 was opened, as a result of which e 2 a was disconnected from the voltage. This prevents the re-excitation of the reversing contactor 2a, which would trigger the countermovement of the slide 2, which would otherwise be caused by the slide when the limit switch E2 is actuated after it has reached its end position.

This is in a simple manner and without additional tools Position "all slides closed" reached, which is necessary for operational reasons is, but so far only achieved by hand or with the help of additional switching elements could be.

This functional sequence is repeated for all others Slide in opening or closing movement by inserting selector switch A in the next positions III, IV, V.

As already mentioned at the beginning, it must be possible for every slide to perform a closing or opening movement as often as desired without this the other sliders are influenced, for example, when running inhibitions in one Slide occur or test runs are required after repair work. this is achieved in a simple manner that the selector switch A briefly in the previous position and is brought back into the current position.

The movements and the end positions of the slides reached in each case are indicated in a manner not shown by signaling means, whereby at any time the current operating phases are easy to control and a source of interference can be determined quickly.

Due to the special design of the selector switch and the control circuit an operating error by the helmsman is completely excluded and also by the low number of switch elements significantly increases the susceptibility of the system to failure degraded.

This special control can of course be used anywhere there where a sequential circuit of sliders is required, for example at Siemens-Martin ovens or the like.

Claims (3)

PATENT CLAIMS: 1. Electric multi-slide control, in particular for blast furnace heaters, for the positive actuation of the slide movement in the order dictated by operation, with a limit switch for each slide which switches the drives of the slide and triggers the switching, whereby the operating positions "wind" and "gas" can be set using a selector switch, characterized in that the selector switch is a roller switch which is between .the operating positions "wind" and "gas" has intermediate positions in which the switching of the slide in the respective one triggered by the limit switch Intermediate position the corresponding level of the switch is interrupted and can be reversed. 2. Control according to claim 1, characterized in that that sliding armature motors are provided as drives for the slide. 3. Control according to claim 1, characterized in that between a normal electric motor and a self-locking gear is connected to the slide. Considered Publications: German Patent No. 614 819; German patent application Z 1057 I a / 24c (published December 27, 1951).