JPH04169B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a medium blowing device that inserts a lance tube into a heat exchanger or the like and performs a medium blowing operation using steam injected from the lance tube.

Figure 1 shows a conventional medium blowing device.
First, this will be explained.

In FIG. 1, 1 is a valve that opens and closes the injection medium, 2 is a injection medium supply pipe connected to the valve 1, and 3 is fixed to the supply pipe 2 at one end, and inserted into the heat exchanger 12, etc. at the other end. The lance tube 4, which can move back and forth, is one or more nozzles provided at the tip of the lance tube 3. Reference numeral 5 denotes a gear box integrally connected to the lance tube 3, in which a pinion gear 6 and a guide roller 7 are arranged in the upper part and the lower part, respectively.

A casing 8 supports the guide roller 7 and is provided with a support roller 9 at its tip, by which the lance tube 3 is supported. Reference numeral 10 denotes an electric motor directly connected to the gear box 5, and the rotation of the electric motor 10 is decelerated by the gear box 5 and transmitted so as to slowly rotate the lance tube 3, and also rotate the pinion gear 6. 11 is a rack fixed to the casing 8 along the lance tube 3, and the pinion gear 6 meshes with this rack 11. Reference numerals 13 and 14 indicate limit switches provided in the casing 8 to control the movement range of the lance tube 3 in the forward and backward directions.

The soot blowing device configured in this way has a heat exchanger 1
The front end is fixed to a wall box 16 directly fixed to the outer wall 15 of the second class, and the part near the rear end is suspended by a support frame 17.
Therefore, the soot blower is located outside the heat exchanger 12 etc. so that it is always exposed to the outside air.

Next, the operation of the conventional soot blower will be briefly explained.

The soot blower is activated by receiving an activation signal from a remote source or from the machine side, and when the electric motor 10 rotates in response to the activation signal, the pinion gear 6 rotates via the gear box 5. Since the pinion gear 6 meshes with the rack 11, it moves along the rack 11 to the right in the figure, so that the lance tube 3 is inserted into the heat exchanger 12.

In FIG. 1, reference numeral A indicates the position of the tip of the lance tube 3 in the initial state, and when the lance tube 3 reaches the position B, the valve 1 is opened, for example, by the action of a timer (not shown). Then, steam as an injection medium is introduced from the supply pipe 2 into the lance pipe 3 and is injected from the nozzle 4. The lance tube 3 further advances inside the heat exchanger 12, but at this time the lance tube 3
As it advances while rotating, steam is injected from the nozzle 4 in many directions within the heat exchanger 12, performing a soot blowing action.

While the lance tube 3 continues to rotate and reciprocate, when its tip reaches the C position, the limit switch 13 provided on the front side of the casing 8 hits the advancing gear box 5, and the switch is turned on. This limit switch 13 is for reversing, and when turned on, the electric motor 10 is reversed. Therefore, the lance tube 3 retreats while rotating in the opposite direction. When the tip of the lance tube 3 retreats to position B, the valve 1 is closed.
Steam injection stops. The lance tube 3 continues to retreat (return operation), and when the gear box 5 hits the limit switch 14, the electric motor 10 stops, and accordingly the lance tube 3 also stops, completing the entire operation.

That is, the gear box 5 is driven by the electric motor 10 and reciprocates between points D and E, which are regulated by limit switches 13 and 14, so that the tip of the lance tube 3 covers the entire width of the heat exchanger 12. Execute the soot blowing motion while rotating and moving at the same time.

By the way, the above-mentioned soot-blowing device of the above-mentioned type is rarely operated continuously, that is, continuously injects steam and blows soot, and receives a activation signal periodically.
It is common to carry out the soot blowing operation in the heat exchanger 12 described above.

Therefore, the lance tube waits at the point position until the next command is issued.

When the soot blower is in a stopped state, the valve 1 is closed, and the supply pipe 2 and lance pipe 3 are cooled to the outside temperature. Therefore, (a) When the soot blowing operation is finished, the supply pipe 2 and lance pipe 3
There is residual steam inside, which is converted into drain during standby and retained inside the supply pipe 2 and lance pipe 3.

(b) When valve 1 opens at the next startup and injection starts, steam in the pipes condenses and a large amount of condensate is generated until the temperatures of supply pipe 2 and lance pipe 3 rise. do.

Since the condensate generated by (a) and (b) above is ejected from the nozzle 4 into the heat exchanger 12 together with steam, it may leak and corrode the constituent materials of the heat exchanger 12, which are in a corrosive atmosphere. In addition, there were many problems such as wear due to drainage, and the effect on carbon steel was particularly large.

Considering these drawbacks of the prior art, one of the inventors of the present invention filed the prior application No. 56-163389
-10574 Publication). In the invention of this prior application, a cavity for draining is formed between the side wall of the heat exchanger where soot is to be blown and the guide box of the soot blowing device. The inner width of this cavity is set in relation to the speed of movement of the lance tube. Although this cavity is effective for drain removal, it has the disadvantage that the size of the cavity must be changed each time the moving speed of the lance tube is changed.

The present invention eliminates such inconveniences, and in order to prevent corrosion and abrasion of the heat exchanger constituent materials caused by the above-mentioned condensate, the present invention provides a drain cutting function that can dispose of condensate without blowing it out into the heat exchanger. The purpose of this invention is to provide an improved soot blower having the following characteristics.

That is, the present invention provides a soot blower equipped with a drain cutter box disposed at the tip of a soot blower having a lance pipe through hole, and a drain extraction pipe communicating with the drain cutter box, when the lance pipe is moved. The soot blowing device is characterized in that it is provided with a limit switch for temporarily stopping it in a drain cutter box, and opens and closes steam to a lance pipe in response to a signal from the limit switch.

An embodiment of the present invention will be described in detail below with reference to FIG. 2. In FIG. 2, the same parts as in FIG. It shall be.

The soot blower according to the present invention shown in FIG.
A major feature of the conventional apparatus shown in the figure is that a drain box 21 is provided between the outer wall 15 of the heat exchanger 12 and the like and the wall box 16.

That is, the drain cutter box 21 has a double structure with a porous pipe 22 inside, and a drain extraction pipe 23 is provided on the lower outer wall. The lance pipe 3 is then connected to the porous pipe 22 of the drain box 21 from the wall box 16 side to the heat exchanger 12 side.
It will move back and forth inside.

Further, the soot blowing device of the present invention is provided with an auxiliary pipe 25 and a blow pipe 26 with a valve 24 interposed therein so that the injection medium can bypass the valve 1.
Furthermore, an intermediate limit switch 27 is provided on the casing 8 to the right of the limit switch 14 to obtain a signal for temporarily stopping the lance pipe 3 at a lower position within the drain cutter box 21. Other configurations are the same as the conventional one.

Next, the operation will be explained.

The electric motor 10 receives a start signal from a remote source or from the machine side.
When started, the lance tube 3 along with the gear box 5,
Move to the right of the diagram. The tip of the lance pipe 3 is connected to the drain cutter box 21 from point A in the wall box 16.
When the gear box 5 hits the intermediate limit switch 27, the electric motor 10 is temporarily stopped by a signal from the limit switch 27. At the same time, valve 24 is opened. The valve 24 is, for example, a solenoid valve, and operates to open upon receiving a signal from the limit switch 27.

When the valve 24 opens, the injection medium, steam, bypasses the valve 1, flows into the supply pipe 2 via the auxiliary pipe 25, the valve 24, and the blow pipe 26, and is ejected from the nozzle 4 at the tip of the lance pipe 3. Here, since the nozzle 4 is located within the perforated pipe 22 of the drain box 21, steam is ejected into the perforated pipe 22. At this time, the drain accumulated in the lance pipe 3 is also jetted out from the nozzle 4 together with the steam, and this drain and the moist steam are discharged to the outside from the drain extraction pipe 23 via the porous pipe 22.

The valve 24 is kept open until the supply pipe 2 and lance pipe 3 reach a predetermined temperature. Since this heating time differs depending on the temperature of the injection medium, the specifications of the soot blower, etc., it is controlled by a variable timer or the like that can set the operating time according to the situation. Therefore, until the temperature of the supply pipe 2 and lance pipe 3 rises, the drain generated inside the supply pipe 2 and lance pipe 3 is ejected from the nozzle 4 into the porous pipe 22 together with steam, and the drain is removed. It is discharged from the pipe 23 to the outside.

When the temperature of the supply pipe 2 and lance pipe 3 rises to a predetermined temperature, the valve 24 closes and the drain cutting operation is completed, and the electric motor 10 is operated again. The lance tube 3 is the heat exchanger 12
When the tip reaches point B, the valve 1 is opened as in the conventional case, and a predetermined soot blowing operation is started. When the tip of the lance tube 3 reaches point C, the electric motor 10 starts rotating in the opposite direction by a signal from the limit switch 13, and the lance tube 3 moves backward.
When the tip of lance tube 3 retreats to point B, valve 1
is closed and the soot blowing operation is completed, but the lance pipe 3 continues to move backward, and when it reaches the stop position, the gear box 5
hits the limit switch 14, stopping the electric motor 10 and ending the entire operation.

Since the soot blowing device is constantly exposed to the atmosphere,
A large amount of condensate and moist steam are ejected during the period from when the injection starts until the temperature of the supply pipe 2 and lance pipe 3 rises. As a result, the constituent materials of the heat exchanger in the corrosive atmosphere often corrode, and the drain often causes abrasion phenomena.

However, in the present invention, in order to solve these problems, the temperature of the supply pipe 2 and lance pipe 3 is raised before the soot blowing work inside the heat exchanger, and the condensate and moist steam generated during the temperature rise are Drain cutter box 21 and porous pipe 22
Since the drain is received by the drain pipe 23 and discharged to the outside through the drain extraction pipe 23, the injection of drain and wet steam inside the heat exchanger is eliminated, and the above-mentioned problem can be solved.

Further, in the present invention, there is no need to relate the size of the drain cutter box 21 to the moving speed of the lance pipe 3, unlike the invention of the prior application. That is, in the present invention, since the limit switch 27 is provided to temporarily stop the lance pipe 3 at the drain cutter box 21, the residence time in the drain cutter box 21 is connected to this limit switch regardless of the moving speed of the lance pipe. can be set using the specified timer. Therefore, there is a feature that the amount of steam ejected from the drain cutter box 21 can be controlled to an appropriate amount.

It goes without saying that the present invention is not limited to the above-mentioned embodiment, but can be implemented with various modifications without departing from the scope of the invention. For example, electric motor 10
Various known control means can be adopted for starting and stopping the valve 1 and opening/closing the valves 1 and 24, and preheating of the supply pipe 2 and lance pipe 3 can be performed by temporarily controlling the valve 1 itself without using the bypass passage of the valve 1. This can also be done by controlling it to open.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing a conventional soot blower, Figure 2
The figure is a configuration explanatory diagram showing an embodiment of a soot blowing device according to the present invention. 1... Valve, 2... Supply pipe, 3... Lance pipe, 4...
Nozzle, 8...Casing, 12...Heat exchanger, 16
...Wall box, 21...Drain cutter box, 22
...Porous pipe, 23...Drain extraction pipe.

Claims (1)

[Claims] 1. In a medium blowing device equipped with a drain cutter box that is placed at the tip of a slide-type medium blower and has a through hole for the lance pipe, and a drain extraction pipe that communicates with the drain cutter box, when the lance pipe is moved, the inside of the drain cutter box A medium blowing device characterized by being provided with a limit switch for temporarily stopping the steam at the lance tube, and opening and closing the steam to the lance pipe according to a signal from the limit switch.