JPS5963499A - Control of nozzle for cleaning - Google Patents

Abstract

PURPOSE:To permit the nozzle for cleaning to scan the whole surface of a rotary heat accumulating body by a method wherein the periodical reciprocating motion of the nozzle is stopped temporarily to disturb the period of the motion so that the rotary motion of the rotary heat accumulating body and the reciprocating motion of the nozzle is not synchronized in a short period. CONSTITUTION:When the main switch S1 of a whole circuit and the sub-switch S3 of a heat accumulating body driving motor M2 are closed and a push-bottom switch PB1 is closed, the operations of the heat accumulating body and a cleaning device are initiated. When a time switch T1 is started at the same time and a contact t1 is closed after a predetermined time, a switch r1 and a solenoid switch MS2 are opened and the motor M2 is stopped. When the contact t2 is closed after a predetermined time from the closing of the time switch T2, the switch T1 is started again and the contact t1 is opened, therefore, the motor M2 is started. The whole surface of the heat accumulating body is scanned and the same may be cleaned by repeating these motions thereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of controlling a cleaning nozzle for removing dust or the like adhering to a heat storage body of a rotary heat exchanger by injecting water vapor or high-pressure air to the dust or the like.

A rotary heat exchanger is normally used as a component of a process. For example, a heat storage body made of layers formed by processing metal ribs into a corrugated shape is accumulated in a disk shape, and is supported by a casing.
One semicircular side is connected to the high temperature duct, and the other side is connected to the cold tact. That is, as shown in FIG. 1 (2) and FIG.
When the high-temperature fluid passes through the part of the fully equipped heat storage body 2 on the high temperature tact 3 side, the sensible heat is supplied to the heat storage body 2 to raise the temperature, and then the stored heat storage body 2 is transferred to the rotation drive device. 5 and enters the low temperature side duct 4, heat is exchanged by radiating heat to the low temperature fluid.

As the above-mentioned high-temperature fluid is often exhaust gas from a normal process, dust, mist, etc. in the gas adhere to the surface of the heat storage element 2, resulting in an increase in pressure loss, a decrease in heat transfer performance, and heat storage. Disturbances such as body corrosion occur. A stationary cleaner or a reciprocating cleaner is usually installed for the purpose of removing kimono from the heat storage body. However, fixed cleaners require a large number of nozzles to be installed in parallel along the radius of the high-temperature side heat storage element and spray cleaning media such as water vapor or air, which requires a large amount of hearing aid and equipment with a large capacity. However, there are problems such as a decrease in heat recovery efficiency due to a decrease in gas temperature due to the medium.

As shown in FIGS. 1 and 2, as a reciprocating type cleaner, a nozzle 7 is provided at the tip of the circular rotating heat storage body 2 excluding the center axis. [411 The drive device (J) installed at the top of the fuselage swings it and injects the cleaning medium from the nozzle 7 onto the heat storage body 2 for cleaning. By moving the nozzle 7, the entire surface of the heat storage body 2 is scanned, thereby cleaning the entire surface.

However, when cleaning is actually performed using such an apparatus, some parts may not be cleaned.

This is the case when there is a coincidence between the reciprocating movement of the nozzle and the rotation of the heat storage body, such that the scanning locus of the nozzle 7 repeats in a pattern that does not cover the entire surface of the heat storage body 2.

A detailed analysis of this point is as follows: In Figure 3, the outer circumferential circle of the heat storage body 2 is Q+, and the circle around the central axis is Q2.
, the center is O1, a point on the outer circumferential circle Q1 is A, and the intersection of OA and circle Q2 is 13, then the nozzle 7 reciprocates between AB.

Although the movement of the nozzle 7 is actually a part of the circumference centered around the base of the injection pipe 8 as shown in FIG. 1, it can be considered to be approximately in the shape of a straight line in the range AB. Then, as shown in Fig. 4, centering on the midpoint C of direct tq A B, points A,
When a point on the circumference of a circle passing through B rotates on the circumference at a constant speed, the "j line A 13 = - straight line A of the downward perpendicular line. For example, the rotation of the heat storage body 2'0.4° is 1 time/min, the number of reciprocations of the nozzle is 1°8 times/min, and gry: diameter of the body 1) (・-1
3) = 2500 skin, diameter α of central shaft part (=DB)...
650&#, then the trajectory S drawn by the point E of the nozzle in one forward movement is a trajectory with A as the starting point and N as the ending point, as shown in FIG.

The trajectory drawn here becomes the reference, and after that, the same trajectory is drawn starting from the end point A', and the point that becomes the end point becomes the starting point. After repeating this, synchronization will be achieved when the trajectory starts at 8 and begins again at Q. Here, if the angle between the starting point A and the ending point is α, then the trajectory will be repeated by the natural number 1 note of the angle.
It matches the numerical value of G Osu's mekari number, and at 7ζ,'-)'!
: Synchronization will start at the least common multiple of the two Riko.

Here, the trajectory that meets the above conditions is d1, then the time required for the trajectory from the starting point A to the ending point N is the nozzle's rotation in A1 section t] and one rotation from C to vjh. The time is 1/18-5/'9 minutes, and the time is Meshiko (c O'/-J/l).
．． 1 x 5/9-41/18 rotations and 7r 6.

In other words, if we consider Δ to be 5 to the handle, we will make a 5/18 rotation with 2 rotations and 7″, and this 5/18 rotation will represent the angle α〒 υ α/360= 5/18 d== :360X5/ 18 = 1000 angles 1
1) The least common multiple of 0 and 360 is 18
When the 9 nozzles 00 reciprocate 18 times, the tab 18/
1.8 == - After 10 minutes, the eight points become somewhat synchronized with the starting point, and then the same trajectory is repeated.

FIG. 5 is a computer-drawn diagram showing the trajectory of the nozzle scanning the heat storage body during continuous operation for 2000 seconds (33 minutes 20 seconds) off the coast of the above-mentioned area. As is clear from this □□□, the scanning repeats a certain pattern and does not cover the entire surface of the heat storage body. As a result, there are areas where the nozzle does not spray and cleaning is not performed, and debris accumulates and causes problems such as clogging.

If the nozzles are synchronized while they move back and forth, we will consider whether there will be any areas that cannot be cleaned.

The range in which the nozzle can effectively spray
Q MI, the thickness of the corrugated layer that forms the heat storage body is 2.
1@, it is desirable that the scanning interval be 6 times or less.

Considering the above conditions, the length of AB is AB = (2500-6501/2 = 9251nl) The number of rotor rotations during one rotation of the nozzle on the rotor surface is 41/2
18 When the entire surface is scanned from a place where the rotation and trajectory intersect, the number of nozzle reciprocations required to scan the entire rotor surface is 925 x 2/6 '41/18 + 135 times The time is 135/1.8-75 minutes, that is, in the case of the above equipment, it is necessary to control so that the nozzle does not synchronize during 135 rotations, which is 75 minutes in time.

Note that if a pattern is drawn in which the scanning lines are close to the margins, there will still be areas that cannot be cleaned even if the scanning lines are not synchronized during this period.

It is difficult to detect whether such synchronization is occurring while the heat exchanger is in operation, and if a strong build-up occurs in some areas, operation must be stopped for a long period of time to remove it. Must be.

In order to solve the above-mentioned problems, the present invention has discovered a method for uniformly cleaning the cleaning nozzle by temporarily stopping the reciprocating movement of the cleaning nozzle to prevent synchronization. That is, in order to break the synchronization, the starting point can be shifted so that it does not start from the same point A in FIG. 3 (9), and the starting point can be shifted by temporarily stopping the reciprocating movement of the nozzle. The cycle of stopping the reciprocating motion may be shorter than the maximum time for synchronization, and in the case of the above-mentioned conditions, the cycle of reciprocating motion may be delayed for 10 minutes during the 18 reciprocating motions of the nozzle.

For example, when calculating the case where the nozzle rotation is stopped for 8 seconds per rotation for 10 minutes to achieve synchronization, the angle at which the starting point shifts during the stop time is 360 x 4. IXo, 8/60 = 19.68 The angle of deviation of the starting point is 360 and the least common multiple of 119.68 is 119.68X9000-1077120360X29
92=1077120 That is, until the nozzle moves back and forth 9000 times, 50
No synchronization for 00 minutes. If synchronization is not performed for a long time in this way, the entire surface of the heat storage body will be reliably scanned until synchronization is achieved. In the calculation, the nozzle stop time is set at the end of one cycle in the above example, but in reality, the stop time e should be added in the middle of the cycle, and if some fluctuations in the stop time are taken into account, Synchronization becomes almost unthinkable.

An example of a circuit for temporarily stopping the reciprocating movement of the nozzle in this manner is shown in FIG.

In the circuit diagram shown in Fig. 6, when the main switch S1 of all circuits, the heat storage body, the sub-switch S2 of the drive motor ura, and the sub-switch S3 of the cleaning device drive motor M2 are closed and the push button switch PB+ is closed, the MI power Switch MS+: Holding switch MSIX, MI electromagnetic switch M
'S2 is closed and the operation of the heat storage body and cleaning device is started. At the same time, time switch T1 starts, and after a predetermined time, tl closes, relay output and time switch T2 are activated. switch rl opens, MS2 opens, and motor M2
stops I:, does. When t2 closes after a predetermined time of T2, I'+1 TI starts and 1. opens, rl and MS2
Since the motor M2 is closed, the motor M2 starts operating, and this operation will be repeated from now on. Cut TR+, TR, 2 is M
, and the protective agent thermal relay of M2, which operates only in case of overload.

to stop the motor.

Fig. 7121 shows the scanning pattern for an example in which the nozzle reciprocates and stops for 0.8 seconds every 120 seconds, and Fig. 8 similarly shows the scanning pattern for an example in which the nozzle stops for 1.2 seconds every 120 seconds, up to 2000 seconds of operation. .

In the case of Figure 7, since the rotation of the nozzle is temporarily stopped, the trajectory will shift sequentially at point M.9 There will be no synchronization, and 20
If you continue driving beyond 00 seconds, the entire area will be filled with scanning lines. In the case of the example shown in Fig. 8, the effect is even more remarkable.In both cases, the entire surface of the heat storage body can be scanned and cleaned, and the rotation of the heat storage body or the cleaning nozzle (
The same effect can be obtained by making several variables (reciprocating) and changing the relative speed of the two, but changing the rotation speed of the heat storage element not only increases equipment costs but also increases the rotation speed. If changed, there is a problem that heat exchange will not be performed uniformly. It is also possible to make the swing speed of the nozzle variable using a variable speed motor, an electromagnetic clutch, etc., but this poses a problem in that the equipment becomes complicated and costs increase.

The present invention achieves its purpose in a relatively simple manner, and therefore has extremely great practical effects.

F7i on page 1 of 41 is just a theory.” FIG. 1 is a top view of the rotary heat exchanger.

Figure 2 is a side view showing a partial cross section of a rotary heat exchanger.
6. Figure 3 is a diagram explaining the nozzle scanning pattern.
.

41. It is a figure explaining the reciprocating motion of the nozzle.

FIG. 5 is a diagram showing the trajectory of a synchronized pattern of nozzle scanning.

FIG. 6 is a diagram showing an example of a circuit that controls the reciprocating movement of the nozzle.

FIGS. 7 and 8 are diagrams showing trajectories of patterns in which nozzle scanning is not synchronized.

Explanation of symbols 1...Casing, 2...Heat storage body, 3...High temperature duct,
4... Low temperature side duct, 5... Rotation drive device, 7...
Nozzle, 8... injection pipe.

Figure 3 Figure 4 Figure 6 Figure 7 mouth

Claims (1)

[Claims] In a control method for a nozzle for cleaning a rotating heat storage body, the nozzle is reciprocated at a constant period along a predetermined trajectory to spray fluid onto the rotating heat storage body to blow off deposits, and the periodic rhythm of the nozzle is temporarily controlled. By stopping the rotary heat storage body or changing its speed, the rotational movement of the rotary heat storage body and the reciprocating movement of the nozzle are prevented from synchronizing in short periods, thereby preventing the nozzle from rotating the rotational heat storage body. A cleaning nozzle control method characterized in that the entire surface can be reliably scanned.