JP2015014416A - Superheated steam generating device and generation method of superheated steam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superheated steam generating device which generates low pressure/high temperature superheated steam.SOLUTION: A superheated steam generating device includes: a steam generating part (a steam boiler) 10 which generates primary steam; a steam tank 11 which collects the steam generated by the steam generating part; and a re-heating part 20 which utilizes an exhaust gas 5 to re-heat the primary steam discharged from the steam tank and generate superheated steam. In the re-heating part, a re-heating conduction part 21 which conducts the primary steam discharged from the steam tank from the upper side to the lower side in a zigzag manner is provided at an exhaust flue 22 which exhausts the exhaust gas used for generating the primary steam from the lower side to the upper side.

Description

The present invention relates to a superheated steam generator and a method for generating superheated steam for generating high temperature steam for use in soil steam disinfection, weed steam removal, and the like.
In particular, the present invention relates to a superheated steam generator and a method for generating superheated steam that reheats steam generated from a portable steam boiler belonging to a small boiler or a simple boiler and takes out the steam in a low pressure / high temperature state.

Conventionally, as a means for performing so-called soil disinfection to kill pathogenic bacteria in soil, there are methods of injecting hot water into the soil or injecting steam.
Regarding the generation of steam for this purpose, for example, as a portable steam boiler belonging to a small boiler or a simple boiler, a dedicated boiler such as a so-called once-through boiler and a flue tube boiler has been used.

  For example, in Patent Document 1, a water supply tank, a fuel tank, and a boiler are mounted on a pedestal placed on a loading platform of a vehicle, and the boiler is provided with a burner that heats water to make steam, The water from the water supply tank is converted into high-temperature and high-pressure steam, and the top of the boiler is equipped with a steam pipe for supplying the generated steam to the steam injection device. A steam generator that can be used is shown.

JP-A-6-253715

However, in the above-described conventional apparatus, since the internal pressure of the boiler is high, there is a high possibility that steam leaks from the dedicated hood, and it is difficult to hold the steam in the dedicated hood.
Furthermore, when used outdoors by a portable type, it has been a major obstacle to safe use.

  The present invention has been made in view of the above problems, and belongs to a small boiler or a simple boiler, and provides a superheated steam generator and a method for generating superheated steam that can discharge high-temperature superheated steam at a low pressure. Objective.

In order to achieve the above object, the present invention has the following features.
(1) The superheated steam generator of the present invention includes a steam generator (steam boiler) that generates primary steam, a steam tank that collects steam generated by the steam generator, and a primary discharged from the steam tank. A reheat unit that reheats steam using exhaust gas to produce superheated steam, and a superheated steam generator comprising:
The reheating section includes a reheating conduction section that conducts the primary steam discharged from the steam tank in a zigzag shape from above to below in an exhaust pipe that discharges the exhaust gas generated from the primary steam from below to above. It is provided.
(2) The superheated steam generator according to the present invention is the above (1), wherein the reheating conducting portion provided in a zigzag shape in the exhaust pipe is provided with a plurality of horizontal pipes arranged in a horizontal direction. A cover box that covers the open ends of the left and right ends thereof, and
The cover box is attached so that the steam discharged from the open end of each horizontal pipe is bundled and distributed and introduced to the open end of each horizontal pipe disposed immediately below the cover box. To do.
(3) In the method for generating superheated steam according to the present invention, the steam generated in the steam generating section for generating primary steam is collected in the steam tank, and the primary steam discharged from the steam tank by the reheating section is discharged into the exhaust gas. A method of generating superheated steam that reheats to produce superheated steam,
The reheating section includes a reheating conduction section that conducts the primary steam discharged from the steam tank in a zigzag shape from above to below in an exhaust pipe that discharges the exhaust gas generated from the primary steam from below to above. It is provided.
(4) The method for generating superheated steam according to the present invention is the above (3), wherein the reheating conducting portion provided in a zigzag shape in the exhaust tube is provided with a plurality of horizontal pipes arranged across the horizontal direction. And a cover box covering the open ends of the left and right ends thereof,
The cover box is attached so that the steam discharged from the open end of each horizontal pipe is bundled and distributed and introduced to the open end of each horizontal pipe disposed immediately below the cover box. To do.

The superheated steam generator of the present invention includes a steam generator (steam boiler) that generates primary steam, a steam tank that collects steam generated in the steam generator, and primary steam discharged from the steam tank. A reheating unit that reheats exhaust gas to produce superheated steam, and causes primary steam discharged from the steam tank to conduct through the reheating conduction part to generate primary steam. In the reheating using the exhaust gas of the burner used, the primary steam can be passed through the reheating atmosphere for a long time through the reheating conducting portion provided in a zigzag shape, so that high temperature steam can be obtained.
In addition, the reheated water vapor is once collected in the cover box, distributed again to a plurality of reheat pipes, and further heated to become superheated water vapor, so that high temperature water vapor can be generated safely at low pressure. Can do.
In addition, the bent part has a problem that the inner diameter is narrow and the steam scale is easily attached and easily clogged. By connecting this part with the cover box, the bent part of the piping of the reheating part can be eliminated. It is possible to eliminate the strain cracking of the metal that frequently occurs at the bent portion of the pipe.
Furthermore, it is possible to improve maintainability such that the bent portions of the plurality of pipes can be replaced by replacing the cover box.

It is a side view of the superheated steam generator of Embodiment 1 of the present invention. It is a front view of the superheated steam generator of FIG. It is a rear view of the superheated steam generator of FIG. It is a side view which shows the internal structure of the steam can body of FIG. It is the outline which shows the structure of the reheating part (conduction part for reheating provided in the zigzag shape) of FIG. 1, (a) is a left view, (b) is a rear view, (c) is a right view. . It is a schematic explanatory drawing which shows the state of the flow of the exhaust gas in the reheating part (conduction part for reheating provided in the zigzag shape) of Embodiment 1 from the side. It is a schematic explanatory drawing which shows the state of FIG. 6 from the back. It is a schematic explanatory drawing which shows the state by which primary water vapor | steam is reheated in the flow of exhaust gas in the reheating part (conduction part for reheating provided in the zigzag shape) of Embodiment 1. FIG. It is a schematic explanatory drawing which shows a mode that primary water vapor | steam is reheated in the flow of exhaust gas, and temperature rises in the reheating part (conductive part for reheating provided in the zigzag shape) of Embodiment 1. FIG. It is the outline which shows the structure of the reheating part (conduction part for reheating provided in the zigzag shape) of Embodiment 2 of this invention, (a) is a left view, (b) is a rear view, (c) is a right side FIG. It is the schematic which shows the structure of the reheating part (conduction part for reheating provided in the zigzag shape) of Embodiment 3 of this invention, (a) is a left view, (b) is a rear view, (c) is a right side FIG.

<Embodiment 1>
Next, an embodiment of the superheated steam generator of the present invention will be described.
FIG. 1 is a side view of the superheated steam generator according to Embodiment 1 of the present invention. 2 is a front view of FIG. 1, and FIG. 3 is a rear view. FIG. 4 is a side view showing the internal structure of the steam can body of FIG.
The superheated steam generator shown in Embodiment 1 includes, as shown in FIGS. 1 to 4, a steam generating section (steam boiler) that generates primary steam, and a steam tank that collects steam generated by the steam generating section. A reheat section for producing superheated steam by reheating the primary steam discharged from the steam tank using exhaust gas,
The reheating unit includes a reheating conduction unit that conducts the primary water vapor discharged from the steam tank in a zigzag shape from above to below in an exhaust pipe that exhausts the exhaust gas generated from the primary water vapor from below to above. It is provided.

<Water vapor generating part>
More specifically, the water vapor generating unit (boiler) 10 supplies fuel such as kerosene or heavy oil to a burner 15 attached to the front surface of the steam generating can body 11 and burns it. The furnace tube 12 provided in is heated to raise the temperature of its internal space. Then, the water around the furnace tube 12 and the smoke pipe 13 that discharges the exhaust gas from the furnace tube 12 is heated, and the water vapor evaporated from the water surface 16 stored in the steam generating can 11 is collected in the steam tank 11a. Primary steam is used.

Furthermore, in the superheated steam generator of Embodiment 1, the reheat part 20 which manufactures superheated steam by reheating the primary steam discharged | emitted from the steam tank 11a using exhaust gas is provided, and it reheats. The primary steam is reheated by the unit 20 to form superheated steam.
By obtaining superheated steam by such stepwise heating, it is possible to obtain superheated steam more efficiently than the conventional method in which the stored water is heated and then superheated steam is made at once.

<Exhaust collecting part>
In addition, an exhaust collecting portion 14 that collects exhaust gas from the plurality of smoke pipes 13 and discharges the exhaust gas into the exhaust cylinder 22 is provided on the back surface of the steam generating can 11.

<Reheating part>
Next, the reheating unit 20 will be described in detail.
FIG. 5 is a schematic view showing the structure of a reheating unit (a reheating conduction part provided in a zigzag shape), where (a) is a left side view, (b) is a rear view, and (c) is a right side view. is there.
In the superheated steam generator of Embodiment 1, the reheating part 20 which reheats primary steam and manufactures heated steam is provided in the back surface (opposite side to the burner 15 attachment side) of the steam generation can body 11. .
The reheating unit 20 uses a reheating conduction unit 21 that conducts the primary water vapor discharged from the steam tank 11a from above to below in a zigzag manner, and the exhaust gas of the burner 15 used for generating the primary water vapor from above. It is provided in the exhaust tube 22 that discharges the air.
The reheating conduction portion 21 is provided in a zigzag shape in the exhaust tube 22 and is provided with a plurality of horizontal pipes 23 that are arranged across the horizontal direction, and a cover box 24 that covers the open ends of the left and right ends thereof. It is equipped with.
The cover box 24 is attached so that steam discharged from the open ends of the horizontal pipes 23 is bundled and distributed and introduced to the open ends of the horizontal pipes 23 disposed immediately below the cover box 24.
Thereby, in the reheating part 20, the reheating conduction | electrical_connection part 21 is heated with the exhaust gas after combustion of the burner 15, and the temperature of the water vapor | steam which passes through the inside is raised, and it is set as superheated steam.

<Horizontal pipe>
Note that the horizontal pipes 23 of the reheating conduction section 21 are provided with a plurality of pipes extending in the horizontal direction in the depth direction, and the plurality of horizontal pipes 23 are provided in multiple stages in the vertical direction. The horizontal pipe group.

<Cover box>
A cover box 24 is attached to the opening side of the both ends of the horizontal pipe 23, and superheated steam discharged after being reheated in the horizontal pipe 23 is introduced into the horizontal pipe 23 immediately below it. It is supposed to let you.
That is, a rectangular cover box 24 is provided at both the left and right ends of the horizontal pipe so as to cover the open ends of the horizontal pipe, and as shown in FIG. The steam outlet 23 b of 23 a and the steam inlet 23 d of the lower horizontal pipe 23 c are communicated with each other in the space inside the cover box 24.

  Similarly, in the right end portion, in the space in the cover box 24, the steam outlet portion of the upper horizontal pipe communicates with the steam inlet portion of the horizontal pipe immediately below.

As can be seen from FIGS. 5A and 5C, a plurality of horizontal pipes 23 are also arranged in the depth direction, and in the horizontal pipe 23 of the embodiment, four pipes are arranged in the depth direction. The entire openings of the plurality of horizontal pipes 23 are in communication with one cover box 24.
In the figure, the right end of the uppermost horizontal pipe 23 is not provided with a horizontal pipe, and the steam from the steam tank is directly introduced into the cover box 24 at the right end. It is like that.

Next, the flow of water vapor and exhaust gas in the reheating unit 20 will be described.
FIG. 6 is a schematic explanatory view showing the state of the flow of exhaust gas in the reheating part (reheating conduction part provided in a zigzag shape) of Embodiment 1 from the side, and FIG. 7 is a schematic explanatory view showing from the back. It is. FIG. 8 is a schematic explanatory diagram illustrating a state in which primary water vapor is reheated in the flow of exhaust gas in the reheating unit (the reheating conduction unit provided in a zigzag shape) according to the first embodiment.

<Flow of water vapor>
The primary steam discharged from the steam tank 11a enters from the introduction port X of the reheating unit 20 and rotates in a zigzag manner such as horizontal pipe → cover box → lower horizontal pipe, and steam below the reheating unit. It is discharged from the discharge port Y to the outside.

<Flow of exhaust gas>
Reference numeral 25 denotes a flow of exhaust gas in the reheating unit 20. The exhaust gas 25 is discharged from the rear portion of the smoke pipe 13 to the lower side of the reheating unit 20 and rises while sewing the gap between the horizontal pipe 23 and the cover box 24 in the reheating unit 20, and It is discharged to the outside through the exhaust port 26.
During this period, the primary steam is heated to superheated steam.

<Measurement result of steam temperature>
FIG. 9 is a schematic explanatory diagram showing a state in which the primary water vapor is reheated in the flow of exhaust gas and the temperature rises in the reheating unit (the reheating conduction unit provided in a zigzag shape) of the first embodiment. It is.
From the result of FIG. 9, the symbol a is the temperature of the surface of the lower cover box in the reheating unit 20 and reaches 270 ° C. in 800 seconds (about 13 minutes) after the burner ignition.
The symbol b is the temperature of the surface of the central cover box in the reheating unit 20 and was 180 ° C. 800 seconds after the burner ignition (about 13 minutes).
The symbol c is the temperature of the upper cover box surface in the reheating unit 20, and was 140 ° C. 800 seconds (about 13 minutes) after the burner ignition.
From the above results, it was found that the primary water vapor was reheated in the flow of the exhaust gas, and became high-temperature superheated steam at 270 ° C. in the reheating unit 20.

<Embodiment 2>
FIG. 10 is a schematic diagram illustrating the structure of the reheating unit according to the second embodiment, where (a) is a left side view, (b) is a rear view, and (c) is a right side view.
The reheating unit 30 of the second embodiment includes a reheating conduction unit that conducts the primary water vapor discharged from the steam tank from above to below in a zigzag manner, and the exhaust gas of the burner used for generating the primary water vapor from below. Although it is the same as the reheating unit of the first embodiment in that it is provided in the exhaust pipe that is discharged upward, the cover box 24 covers the open ends of the left and right ends of the horizontal pipe 23 disposed in the reheating conduction unit. However, it covers the open ends of the left and right ends of the four-stage horizontal pipe.
That is, a zigzag circuit is formed for every two horizontal pipes, and the steam discharged from the open ends of the upper two horizontal pipes is distributed and introduced to the open ends of the lower two horizontal pipes. It has become.
Thereby, in the reheating part 30, a high temperature steam can be created, without raising the pressure of water vapor.

<Embodiment 3>
FIG. 11 is a schematic diagram showing the structure of the reheating unit of the third embodiment, where (a) is a left side view, (b) is a rear view, and (c) is a right side view.
The reheating unit 40 of the third embodiment includes a reheating conduction unit that conducts the primary water vapor discharged from the steam tank in a zigzag shape from above to below, and the exhaust gas from the burner used for generating the primary water vapor from below. It is the same as the reheating unit of the second embodiment in that it is provided in the exhaust pipe that is discharged upward and covers the open ends of the left and right ends of the four-stage horizontal pipe with the cover box. The difference is that there are two horizontal pipes arranged in the depth direction of the horizontal pipe 23 arranged in the section.
Thereby, it can respond to the apparatus which reduces the number of the horizontal pipes in the reheating part 40, reduces cost, and produces a small amount of high temperature steam.

The superheated steam generator of the present invention includes a steam generator (steam boiler) that generates primary steam, a steam tank that collects steam generated in the steam generator, and primary steam discharged from the steam tank. A reheating unit that reheats exhaust gas to produce superheated steam, and causes primary steam discharged from the steam tank to conduct through the reheating conduction part to generate primary steam. In the reheating using the exhaust gas of the burner used, the primary steam can be passed through the reheating atmosphere for a long time through the reheating conducting portion provided in a zigzag shape, so that high temperature steam can be obtained.
In addition, the reheated water vapor is once collected in the cover box, distributed again to a plurality of reheat pipes, and further heated to become superheated water vapor, so that high temperature water vapor can be generated safely at low pressure. Can do.
For these reasons, the present invention has very high industrial applicability.

10: Steam generation part (steam boiler)
11: Steam generating can body 11a: Steam tank 12: Furnace tube 13: Furnace tube 14: Exhaust collecting unit 15: Burner 16: Water surface 20: Reheating unit 21 of Embodiment 1: Reheating conduction unit 22: Exhaust tube 23 : Horizontal pipe 23a: Uppermost horizontal pipe 23b: Steam outlet 23c of uppermost horizontal pipe: Lower horizontal pipe 23d: Steam inlet 24 of lower horizontal pipe 24: Cover box 25: Exhaust gas 26: Exhaust port 30 : Reheating unit 40 of the second embodiment: Reheating unit X of the third embodiment X: Reheating unit inlet Y: Reheating unit steam outlet

Claims (4)

A steam generation section (steam boiler) that generates primary steam;
A steam tank that collects the steam generated in the steam generating section;
A reheating unit for producing superheated steam by reheating the primary steam discharged from the steam tank using exhaust gas;
A superheated steam generator comprising:
The reheating unit
A conduction part for reheating for conducting the primary water vapor discharged from the steam tank from above to below in a zigzag shape;
An overheated steam generator characterized in that it is provided in an exhaust cylinder for discharging the exhaust gas for generating the primary steam from below to above. The conduction part for reheating provided in a zigzag shape in the exhaust pipe is
A plurality of horizontal pipes arranged in a horizontal direction;
A cover box covering the open ends of the left and right ends thereof,
The cover box is
Bundle the steam discharged from the open end of each horizontal pipe,
2. The superheated steam generator according to claim 1, wherein the superheated steam generator is attached so as to be distributed and introduced to an open end of each horizontal pipe disposed immediately therebelow. 3. The steam generated in the steam generating section that generates primary steam is collected in a steam tank,
A method for generating superheated steam that produces superheated steam by reheating primary steam discharged from a steam tank by a reheating unit using exhaust gas,
The reheating unit
A conduction part for reheating for conducting the primary water vapor discharged from the steam tank from above to below in a zigzag shape;
A method for generating superheated steam, characterized in that it is provided in an exhaust cylinder for discharging the exhaust gas for generating primary steam from below to above. The conduction part for reheating provided in a zigzag shape in the exhaust pipe is
A plurality of horizontal pipes arranged in a horizontal direction;
A cover box covering the open ends of the left and right ends thereof,
The cover box is
Bundle the steam discharged from the open end of each horizontal pipe,
4. The method of generating superheated steam according to claim 3, wherein the superheated steam is attached so as to be distributed and introduced to the open ends of the horizontal pipes disposed immediately therebelow.