SK24295A3 - Leading method of drawed elements - Google Patents

Abstract

The guidance system is used to displace the elongate cleaning element in a meandering path for directing a cleaning jet onto the wall surface to be cleaned. The cleaning element is supported by a pair of cardan linkages (3, 4), one of which is held stationary while the other is displaced axially along a spindle (6), supported at its ends for displacement along 2 further spindles (8). The first spindle and one of the second spindles have inductive end switches (11, 12, 13, 14), coupled to a programmed control device (16), 2 of the end switches (13, 14) indicating reference points in the horizontal and vertical directions and the other 2 end switches (11, 12) indicating the spindle (6, 8) rotation as a measure of the cardan linkage (4) displacement. To the route the proportional impulses of the end switches (11, 12) are in controlling compared (16) with the pre-stated figure of cleaning jet and spindles (6, 8) are set according to th e formulary figure of cleaning jet.

Description

Area, techniques

The invention relates to a method for guiding elongated elements with the features of the preamble of claim 1.

BACKGROUND OF THE INVENTION

Such an elongated element may be a sootblower tube for cleaning the surfaces of the tube walls flowing through the heat exchange medium and bypassed by the flue gases loaded with dust particles (DE-OS 41 42 448). The sootblower emerging from the sootblower removes dust deposits on the wall surfaces. In order for this blowing jet to reach the entire surface of the walls, the blower tube is guided so that its outlet end describes horizontal and consecutively vertical sections of the path and thus, in general, performs a sequence of meander-like movements. Keeping this shape of the blowing path is achieved by driving the spindle at a uniform speed for a certain time and then turning on the second spindle. In operation with harsh operating conditions, contamination and wear can cause a time-controlled, rigid, spindle-driven operation. Since the spindles in this case are to be switched, a new direction of movement is initiated before the predicted turning point of the blowing figure is reached. As a result, the wall surface is only imperfectly cleaned.

In order to clean the aforementioned sootblower only the area of contamination that is limited to the area and circumferentially limited, it is proposed in DE-PS 281 452 to operate it. A blowout figure adapted to the arrangement of the wall surfaces and the visually detected contamination state is stored in the memory of this control. This blowing figure is transmitted to the spindles by the signal generator and the path measuring device.

2. Summary of the Invention

It is an object of the invention to control an element of this type mounted in two cross-joints so that it can be. precisely adhered to a predetermined blowing figure, consisting of several turns. The control according to the invention is path-dependent and no longer time-dependent, thus allowing exact adherence to the cross-joint path and precise adjustment of the moving element. The observance of the travel is solely dependent on the drive mechanism of the element. Frequency control for three-phase brake motors used for spindle drive can advantageously be assigned to this control. By this speed control, the duration of action of the blower element on a certain wall area can be varied according to the degree of soiling. The use of revolutions is meaningful because the control according to the invention is only path dependent, so that the speed at which the blowing current is guided over the wall surface does not affect the exact design of the blowing pattern.

Overview of the figures in the drawing

An exemplary embodiment is shown in the drawing and will be explained in more detail below. They show:

Fig. 1 shows a side view of a sootblower arrangement, FIG. 2 wiring diagram,

Fig. 3 blowing figure.

Examples

The soot blower is designed as a blower. the water tube has a tube 1 through which water is guided as a blowing medium. The outlet end of the blow tube extends through the aperture closed by the lid 2 to the focus of the steam generator bounded by the tube walls. At the lid 2, the blow tube is held by a first cross tube

3. The rear end of the blow tube 1 is held in the second cross-member 4. The second cross-member 4 is mounted on a guide sleeve which is axially displaceable on the first spindle 6. The first spindle 6 is driven by a three-phase brake motor 2. The ends of the first spindle 6 are arranged axially displaceably on two parallel spindles 6 arranged in parallel. The three-phase brake motor 4 drives one of the spindles 4 directly and the second spindle 8 by a chain drive 10. When the first spindle 4 is rotated, the guide sleeve 5 is moved with the second universal joint 4, thereby moving the outlet end of the blower tube 1 and thus . Similarly, when the second spindle 6 is rotated, a horizontal movement of the blowing stream occurs.

Alternately switching on the spindles 6, 6 produces a blowing figure reproduced in Figure 3, which consists of horizontal and turning points. AFTER. The blowing pattern contains a reference point zero point of the coordinate system. The distance between the starting point PS and the first turning point in the horizontal is marked X, the distance between the turning point to the left and the turning point to the right in the horizontal is marked X ₂ . During this phase of movement, the spindles 6 are in operation. The path that the blowing current travels vertically when the spindle 6 is on is indicated by Y. XY indicates the path to the turning point when all spindles £, £ are turned on. The height limit of the blowing figure is marked Y. The frame Z indicates the boundary of the blowing figure given by the drive mechanism design.

According to FIG. 2, two proximity inductive limit switches 11, 12, 13, 14 are each assigned to the first spindle 8 and one of the second spindles. The limit switches 11, 12 measure by pulse the spindle speed, from which the geometrical conditions can be determined The end switches 13, 14 define the reference point PO. The limit switches 11 to 14 are the control line 15

-4connected with memory programmable control .16. In this control 16, a blowing figure (Figure 3) is to be stored, to be passed through the blowing current. In control 16, the pulses received by the limit switches 11, 12 are compared with the blowing figure stored in the memory.

The three-phase brake motors 12, 2 are each provided with a contactor 17 for rotating the spindles 8 and 8 back and forth. The contactors 17 are connected to the control by the control line 16. Further, a frequency converter 18 is provided which is connected to the contactors 17 and to the control 16.

After releasing the starter automatics, it runs to the reference point PO. to set the path measurement system to zero. Reaching the reference point PO is signaled in the X and Y directions by limit switches 13., 14. · Then it approaches the starting point PS. When the starting point PS is reached, the blowing medium supply to the sootblower opens and begins to move along the path of the blowing figure. Here, the pulses sensed by the limit switches 11, 12 are calculated as a measure for the travel

passed an in horizontal and vertical direction / measured value / a they are compared with the values programmed

in control / prescribed value /. If the measured value is equal to the prescribed value, the path condition is met and started

next step movement. If the blowing figure is completed, closes supply of blowing medium and run to the point quiet PR. if should change the duration of the blowing current,

the number of revolutions of the three-phase brake motors 7, 2 is changed by the frequency converter 18. This change in the number of revolutions does not affect the design of the blowing figure, since the limit switches 11, 12 sense the path and operate independently of how fast the blowing figure is completed.

The described control is also suitable for other elongated elements located in two cross-joints outside the soot blower.

Claims (2)

PATENT CLAIMS A method of guiding an elongated element, such as a soot blower for cleaning wall surfaces, according to a predetermined meandering blowing pattern, wherein the element is mounted on two spaced apart cross-joints (3, 4), one immovably held and the other is axially displaceable on a first spindle (6), the ends of which are mounted axially displaceably on two parallel spindles (8) arranged in parallel, and inductive proximity switches (11, 12, 13) are associated with the first and one of the second spindles, 14, which are connected to a memory programmable control (16), characterized in that two limit switches (13, 14) register a reference point in horizontal and vertical direction and two limit switches (11, 12) of the spindle speed (6, 8) (as a measure of the travel of the second universal joint) (4), that the proportional pulses of the limit switches (11, 12) are compared in the control (16) with the predetermined blowing figure and that the spindles (6, 8) are actuated according to the prescribed blowing figures. Method according to claim 1, characterized in that the spindles (6, 8) are driven by a three-phase brake motor (7, 9) using frequency control and that the number of revolutions of the three-phase brake motor (7, 9) is changed by the control (16). .