JP2503144Y2 - Chemical cleaning liquid circulation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention cuts the high temperature steam pipe and installs a temporary pipe for chemical cleaning of oxide scale generated on the inner surface of the high temperature steam pipe at the boiler outlet. The present invention relates to a chemical cleaning liquid circulation device which is connected to a main shut-off valve part on the turbine inlet side and circulates a cleaning liquid by a circulation pump.

[Prior Art] When chemically cleaning hard steam oxidation scale (Cr-Mo) generated on the inner surface of a high-temperature steam pipe made of a low-alloy steam pipe at the boiler outlet, the high-temperature steam pipe is cut to remove stainless steel material. Conventionally, a chemical cleaning liquid circulation device, which separates the used pipe from the boiler main body side, connects the main inlet valve of the turbine inlet side with a temporary pipe, and circulates the cleaning liquid by a circulation pump, is shown in FIG. It was structured.

In the figure, 1 is a temporary circulation pump, 2 is a temporary pipe for cleaning, and 3 is
Is a high temperature steam pipe at the outlet of the boiler to be cleaned, 4 is a main steam stop valve, and 5 is a temporary cleaning pipe similar to the temporary cleaning pipe 2. The chemical cleaning liquid is circulated in parallel with the two series of high temperature steam pipes 3, 3 and the chemical cleaning liquid discharged from the temporary circulation pump 1 is divided into two series by the temporary cleaning pipe 2. It is supplied to the high-temperature steam pipes 3,3 from the boiler final heater outlet pipe A, and again in the temporary cleaning pipe 5 via the main steam stop valves 4,4, ... Located on the turbine inlet side of the high-temperature steam pipe 3. The system is integrated into one system and taken into the temporary circulation pump 1.

[Problems to be Solved by the Invention] In the structure as described above, it takes a long time to completely remove the hard steam oxidation scale generated on the inner surface of the high temperature steam pipe 3 which is a low alloy steam pipe. With this,
The cleaning temporary pipes 2 and 5 must be of a large size, and the temporary circulation pump 1 must also have a large capacity, which has the disadvantage of requiring a large amount of chemicals in the chemical cleaning liquid. It was

The present invention has been made in view of the above situation,
The purpose is to reduce the amount of chemicals in the chemical cleaning liquid by configuring the temporary circulation pump, temporary cleaning piping, etc. with a small one, while increasing the cleaning efficiency to create a hard steam oxidation scale in a short time. It is an object of the present invention to provide a chemical cleaning liquid circulating device that can be completely removed.

[Means and Actions for Solving the Problems] That is, according to the present invention, the circulation path of the temporary disposition pipe is connected in series to the high-temperature steam pipe, and the cleaning liquid of It is equipped with a bypass path with a regulating valve that reverses the circulation direction.By temporarily controlling the opening and closing of the regulating valve, the chemical cleaning solution is circulated in series while reversing the circulation direction for each unit of time. The capacity of the pump and the size of the temporary cleaning pipe are reduced to significantly reduce the labor and cost required for hypothetical construction, and increase the cleaning efficiency while reducing the amount of chemical cleaning liquid and the amount of chemicals in the liquid. It becomes possible to completely remove the hard steam oxidation scale in a short time.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of the temporary circulation pump 1,
Since the structures of the high temperature steam pipe 3 and the main steam stop valve 4 are the same as those shown in FIG. 2, the same parts are designated by the same reference numerals and the description thereof will be omitted.

Now, while the temporary cleaning pipe 6 for connecting these is arranged at the boiler final heater outlet pipe section A of the high temperature steam pipes 3 of the two systems, the main steam located at the downstream end of the high temperature steam pipe 3 is arranged. A temporary cleaning pipe 7 that constitutes a series circuit including the temporary circulation pump 1 is provided for the stop valves 4, 4, .... And
A bypass passage 9 provided with adjusting valves 8a, 8a and 8b, 8b is arranged between the temporary circulation pump 1 of the temporary cleaning pipe 7 and the main steam stop valve 4. The adjusting valves 8a, 8a and 8b, 8b are switch-controlled so that when one of the sets is open, the other set is closed.The adjusting valves 8a, 8a are open. , When the adjusting valves 8b, 8b are closed, the arrow a in the figure
The chemical cleaning liquid circulates in this series-connected path as shown by, and when the adjustment valves 8b, 8b are open and the adjustment valves 8a, 8a are closed, the chemical cleaning liquid is connected in series as shown by the arrow b in the figure. The route will be circulated in the opposite direction to the above.

Accordingly, the temporary circulating pump 1 is operated to circulate the chemical cleaning liquid while controlling the open / closed states of the adjusting valves 8a, 8a and 8b, 8b at a specific unit time, for example, every hour, thereby cleaning the temporary cleaning pipe. 2 connected in series by 6,7
The chemical cleaning liquid circulates in the high temperature steam pipes 3, 3 of the system while reversing the direction every hour.

Since the temporary cleaning pipes 6 and 7 are for connecting the high temperature steam pipes 3 and 3 in series, the size of the pipes used for the temporary cleaning pipes 6 and 7 can be configured for one system. Similarly, the temporary circulation pump 1 can also be configured to have a capacity sufficient to circulate one system of chemical cleaning liquid to obtain the required cleaning capacity, while the chemical cleaning liquid reverses the circulation direction at regular intervals. The cleaning ability is greatly improved. Further, since the temporary cleaning pipes 6 and the temporary cleaning pipes 7 are collectively arranged at a fixed location, the overall pipe length is also shorter than that of the parallel route shown in FIG. It is possible,
Considering that the size of the pipe can be reduced, as a result, the labor and cost required for the cleaning work can be significantly reduced.

[Effects of the Invention] As described in detail above, according to the present invention, the tube is cut during the chemical cleaning of the hard steam oxidation scale generated on the inner surface of the high temperature steam tube which is the low alloy steam tube at the boiler outlet. In the chemical cleaning liquid circulation device that separates the piping using stainless steel from the boiler main body side, installs temporary piping and connects it to the main inlet valve of the turbine inlet, and circulates the cleaning liquid with a circulation pump, temporarily installs it against the high temperature steam pipe. The piping circulation path has a series structure, and a bypass path with a regulating valve that reverses the circulation direction of the cleaning liquid at regular intervals is provided for this series circulation path, so the opening and closing of the regulating valve is switched. By circulating the chemical cleaning solution in series while reversing the circulation direction every unit time, the cleaning efficiency is increased and the hard steam oxidation scale is completed in a short time. Although it can be completely removed, the capacity and volume of the temporary circulation pump and the size of the temporary piping for cleaning can be configured to be small, so the labor and cost required for hypothetical construction can be significantly reduced, and the amount of chemical cleaning liquid and its content can be reduced. It is possible to provide a chemical cleaning liquid circulating device that can reduce the amount of chemicals in the chemical cleaning liquid.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic structure according to an embodiment of the present invention, and FIG. 2 is a diagram showing a basic structure of a conventional chemical cleaning liquid circulating apparatus. 1 …… Temporary circulation pump, 2,5,6,7 …… Temporary piping for cleaning,
3 …… High temperature steam pipes 3,4 …… Main steam stop valve, 8a, 8b ……
Regulator valve, 9 ... Bypass path.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryoichi Noguchi 5-7 Atsunoura-machi, Nagasaki-shi, Nagasaki Nagahishi Engineering Co., Ltd. (56) References JP 62-141405 (JP, A) Showa 47-29121 (JP, Y1) Showa 52-34482 (JP, Y2)

Claims (1)

(57) [Scope of utility model registration request] 1. In chemical cleaning of hard steam oxidation scale generated on the inner surface of a high temperature steam pipe at the boiler outlet, the high temperature steam pipe is cut and separated from the boiler body side, and a temporary pipe is provided to provide a turbine inlet. In a chemical cleaning liquid circulation device that is connected to a side main blocking valve and circulates a cleaning liquid by a circulation pump, the circulation path by the temporary pipe has a structure in which a plurality of high temperature steam pipes are connected in series to the circulation pipe, A chemical cleaning liquid circulating device comprising a bypass route with a regulating valve for reversing the circulation direction of the cleaning liquid at regular intervals with respect to the circulation route of the structure connected in series.