JPH0742901A - Vertical fire tube boiler having promotor - Google Patents

Abstract

PURPOSE:To make a flow of combustion gas as one flow and simplify a structure by a method wherein fire tubes are inserted into water pipes of a vertical water pipe boiler, an eccentric flow of combustion gas is eliminated by applying the fire tubes as passages for the combustion gas and at the same time a heat transferring promotor is arranged in each of the fire tubes. CONSTITUTION:Annular headers 1 and 2 are arranged at an upper part and a lower part. Water pipes 3 are arranged between these headers. Fire tubes 4 are inserted into the water pipes 3. The water pipes 3 are arranged in an annular form so as to form a water-cooled wall of a combustion chamber 5. In addition, a burner 6 is installed at an upper part of the combustion chamber 5, and a combustion gas passage 7 communicating with the fire tubes 4 is arranged at a lower part of the combustion chamber 5, respectively and further a fire chamber 8 communicating with a chimney is arranged at an upper part of the upper header 1. In turn, A down pipe 9 for use in naturally circulating boiler water is arranged outside the water pipes 3. A swirl tape is inserted into the fire tubes 4 and a heat transfer coefficient from combustion gas within the tubes into the fire tubes 4 is promoted. With such an arrangement as above, a temperature of the combustion gas is lowered with a passage of combustion gas being applied as one upward flow and the gas is applied as a boiler discharged gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention achieves effective utilization of a heat transfer surface by eliminating uneven flow of combustion gas, and a heat transfer promoter causes combustion gas to flow only once in a smoke tube to attain a sufficiently low temperature as exhaust gas. The present invention relates to a vertical smoke-water boiler having a simplified structure.

[0002]

2. Description of the Related Art An upper and lower annular pipes are provided and connected by water pipes (normally straight pipes), and the water cooling walls of the combustion chamber are formed by the inner rows of the annular water pipes. A vertical water tube boiler is known in which an evaporator tube or a downcomer tube is formed in an annular outer row, and a passage for combustion gas is provided between the water tubes in the inner and outer rows.

In the conventional combustion gas passage of this boiler, the combustion gas flowing down through the combustion chamber is evenly distributed around the circumference from a gap provided between the water pipes below the water pipe forming the water cooling wall of the combustion chamber. Whether to flow to the passage of the combustion gas, or to flow to the passage of the combustion gas uniformly from the gap provided between the water pipes over the entire height of the water cooling walls arranged in a ring to the entire height,
It is built. However, this desire for homogenization is not achieved due to uneven flow of flame and combustion gas in the combustion chamber and uneven flow due to uneven distribution of chimneys or flues at the boiler outlet. Therefore, since the heat transfer surface is not effectively used due to the uneven flow of the combustion gas, there is a drawback that the heat transfer area must be increased accordingly.

Further, in the conventional vertical water tube boiler, the row of the evaporation tubes on the outside of the combustion gas passage make the water tubes stick to each other or form a wall made airtight by fins, and the combustion gas leaks to the outside of the boiler. It is normal to prevent
In this way, when the wall is made of the water pipe, the outer side thereof does not come into contact with the combustion gas, so that it does not become an effective heat transfer surface. Therefore, in some cases, a wall made of a refractory material is provided outside the evaporation pipe to prevent the combustion gas from leaking out of the boiler. According to this, although the entire surface of the evaporation tube becomes a heat transfer surface, there is no waste, but the wall of the refractory material is structurally weak and is therefore easily damaged.

On the other hand, in the furnace tube smoke tube boiler, the combustion gas exiting the furnace tube flows uniformly in the smoke tube and does not flow unevenly. This is because the combustion gas passage in the smoke pipe is clear and the pressure loss is large, so that it is not affected by the flow before and after the smoke pipe (flame and combustion gas drift in the combustion chamber, combustion gas drift in the flue). However, since the flue tube boiler has a large installation area and a large volume of water and steam, it has the drawback of causing great damage if it should burst.

In addition, a conventional vertical water tube boiler has a smoke tube whose both ends are bent inside the water tube, and the lower end is located below the water tube.
The upper end is connected to the upper part of the water pipe, and the combustion gas that comes out of the combustion chamber enters this smoke pipe from the lower part of the water pipe and exits from the upper smoke pipe of the water pipe.In this boiler, the combustion gas left the smoke pipe. It is said that the combustion gas flows down the outside of the after-water pipe, and the combustion gas that has flowed outside the water pipe at a right angle to the water pipe stirs the flow of the flowing combustion gas to promote heat transfer.

Further, a smoke pipe having a bent lower end is inserted into the water pipe, the lower end is connected to the side wall near the lower pipe, and the upper end is connected to the upper end near the upper pipe, and the combustion gas coming out of the combustion chamber is used as the smoke pipe. Some enter at the bottom of the and some exit at the top of the smoke tube. Even in this boiler, the combustion gas flows down the outside of the water pipe after exiting the smoke pipe.

These boilers have the following drawbacks. That is, it is complicated in structure and work to insert the smoke pipe with the lower end or the upper and lower ends bent into the water pipe. The temperature of the combustion gas is still high in the upper part of the smoke tube, and the outer wall in contact with the passage of the combustion gas is not water-cooled, so that it burns out. The smoke tube is a curved tube, so it is difficult to clean.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the conventional vertical water tube boiler, that is, the large deviation of the combustion gas, and the drawback of the furnace tube smoke tube, that is, the large water capacity. The advantage of the vertical water tube boiler, that is, the small water volume, and the advantage of the furnace tube smoke tube boiler, that is, the low uneven flow, are combined to obtain a vertical water tube boiler with less uneven flow and a small water volume, Further, it is to obtain a vertical water tube boiler having a simple structure. As a result, there is no waste of heat transfer area, there is no burning of the outer wall, and a small vertical water tube boiler can be obtained.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a smoke pipe is inserted into a water pipe of a conventional vertical water tube boiler, and the smoke pipe is used as a passage for the combustion gas to prevent the uneven flow of the combustion gas of the vertical water pipe boiler. In addition to eliminating it, a heat transfer promoter is installed in this smoke tube to make the combustion gas flow once, simplifying the structure and eliminating the water tube that is not effective as a heat transfer area for creating the combustion gas passage. Therefore, by utilizing the small amount of water, the advantages of both can be utilized while eliminating the drawbacks of both.

There are various heat transfer promoters,
Consider a swirl tape and a spiral protrusion extrusion tube that have a large increase in heat transfer and a small increase in ventilation resistance.

[0012]

In the vertical smoke-water pipe boiler of the present invention, the combustion gas exiting the combustion chamber enters the smoke pipe provided in the water pipe, but since the passage area of the smoke pipe is relatively small, the uneven flow of the combustion gas is reduced.
Since the swirl tape is installed in the smoke pipe or the smoke pipe is a spiral projection extruded pipe, the heat transfer coefficient of the combustion gas to the smoke pipe is about twice, and the exhaust gas can be passed through the smoke pipe only once. Is cooled to a sufficiently low temperature. Therefore, the vertical smoke-water boiler according to the present invention has a simple structure, a small size, and a robust structure without a complicated structure when the combustion gas is made to flow twice, a waste water pipe, and a weak outer wall when the water pipe is eliminated.

[0013]

DETAILED DESCRIPTION FIG. 1 details one embodiment of this patent. As shown in the drawing, annular pipes 1 and 2 are provided above and below, a water pipe 3 is provided between a lower end of the pipe 1 and an upper end of the pipe 2, and a smoke pipe 4 is inserted into the water pipe. The top and bottom of the pipe line 1 and the pipe line 2
Attach to the bottom edge of. This water pipe is annularly arranged to form a water cooling wall of the combustion chamber 5. A burner 6 is provided in the upper part of this combustion chamber concentrically with the upper pipe side, a combustion gas passage 7 leading to the smoke pipe is provided below the lower pipe side, and a smoke chamber 8 leading to a chimney is provided above the upper pipe side.
To provide. In this boiler, a downcomer pipe 9 is provided outside the water pipe 3 to naturally circulate boiler water. When the swirl tape 11 shown in FIG. 2 is put in the smoke tube, the heat transfer coefficient from the combustion gas in the tube to the smoke tube is promoted, and even if the passage of the combustion gas is made upward once, the temperature of the combustion gas is sufficiently lowered, and the boiler exhaust gas is exhausted. As a result, the boiler becomes compact.

Further, this swirl tape can be rotated from above the boiler and can be moved up and down by a device (not shown).
This removes soot and ash that has settled inside the smoke tube.

As shown in FIG. 3, if the above-mentioned smoke tube is a spiral projection extruded tube (a tube processed from the outside and extruded the spiral projection inside) 12, the heat transfer from the combustion gas in the tube to the smoke tube. The coefficient is promoted, whereby the temperature of the combustion gas is sufficiently lowered by allowing the combustion gas to flow upward through the smoke pipe only once, and the exhaust gas can be used as boiler exhaust gas, so that the boiler becomes compact.

Although not shown, this smoke pipe is provided with an inlet for washing water in the upper part of the smoke pipe and a drain hole in the lower part (furnace bottom) so that the smoke pipe can be washed with water. be able to.

Although there is a slight difference in the numerical values between the swirl tape and the spiral projection extrusion pipe, when the heat transfer promoter is inserted, the heat transfer coefficient from the combustion gas to the smoke pipe is when the number of smoke pipes does not include the heat transfer promoter. If it is the same as, the ventilation resistance will be about 4 times and the ventilation resistance will be about 6 times. Therefore, if the number of smoke pipes is increased so that the heat transfer coefficient is about 2 times, the ventilation resistance and the length of the smoke pipe will also be shortened. Yes, it will double. Since the ventilation resistance of the smoke pipe part of a vertical smoke pipe boiler is originally small, it can be increased about twice.

FIG. 4 is a detail of another embodiment of this patent.
As shown in the figure, the water pipes 10
Is provided between the lower end of the pipe side 1 and the upper end of the pipe side 2, and this water pipe is annularly arranged to form a water cooling wall of the combustion chamber 5. Also, water pipe 3
Is provided between the lower end of the pipe line 1 and the upper end of the pipe line 2, the smoke pipe 4 is inserted into the water pipe, and the upper and lower sides of the smoke pipe are attached to the upper end of the pipe line 1 and the lower end of the pipe line 2. The water pipe 3 is annularly arranged and the smoke pipe 4 serves as a passage for combustion gas. Further, a burner 6 is provided in the upper part of the combustion chamber concentrically with the upper pipe side, a combustion gas passage 7 communicating with the smoke pipe is provided under the lower pipe side, and a smoke chamber 8 leading to a chimney is provided above the upper pipe side. To provide. In this boiler, a downcomer pipe 9 is provided outside the water pipe 3 to naturally circulate boiler water. A swirl tape is inserted in the smoke tube or the smoke tube is used as a spiral projection tube to increase the heat transfer coefficient, thereby making the combustion gas in the smoke tube flow once.

FIG. 2 is an enlarged view of the swirl tape, and FIG. 3 is an enlarged view of the spiral protrusion extrusion tube.

[0020]

In contrast to the conventional standing tube boiler, the boiler of the present invention has a structure of the boiler of the present invention, in which the combustion gas passes through the inside of the smoke tube, so that the nonuniform flow of the combustion gas is almost completely eliminated, resulting in a wasteful heat transfer surface. Disappears. Also, the installation of the heat transfer promoter significantly reduces the size of the smoke tube, and hence the boiler, and improves the combustion gas in a single flow, thus simplifying the structure. Further, as in the case of the conventional standing tube boiler, the water / steam is contained in the water tube 10 and the downcomer tube 9 and the water tube 3 having a relatively small diameter, and the upper and lower tubes having a relatively small internal volume, so that the amount of water held is extremely small, Explosive power is small even if it should burst,
It is safe, but because the smoke pipe is inserted in the water pipe 3 and the heat transfer area, and thus the boiler, is downsized due to the installation of the heat transfer promoter, the amount of water held is even smaller and it is safe. In addition, including the smoke tube boiler of the present invention,
In the conventional standing tube boiler, steam separation is carried out in the pipe section 1. However, if the inner volume of the pipe section 1 is small and the steam separation cannot be performed sufficiently, a separate steam separator is provided. In this case, water also collects in the lower part of the steam separator, but since this amount is also small, safety is not impaired.

Further, the boiler of the present invention has the following advantages over the conventional standing water pipe boiler. That is, since the smoke pipe is a straight pipe, the structure and work are simple. By adopting a heat transfer promoter, the combustion gas passage becomes a single flow, and the boiler structure becomes simple and compact. On the contact heat transfer surface, the combustion gas passes only inside the smoke pipe, and does not pass outside the water pipe, so cleaning can be completed completely and easily. The swirl tape placed inside the smoke tube can be rotated and moved up and down, so the inside of the smoke tube can be cleaned easily and completely. The spiral projection extrusion pipe is washed with water, but since the smoke pipe is a straight pipe, cleaning is simple and reliable.

As described above, the vertical smoke pipe boiler according to the present invention is different from the conventional similar smoke pipe boiler in that the structure is simple because the direct smoke pipe / heat transfer promoter is used and the flow is one time.
Moreover, it has the advantages that it is robust, there is no waste of heat transfer surface, it is easy to clean with swirl tape, and it is a straight pipe so that washing is complete. It completely overcomes the problems such as complexity, waste of heat transfer surface, and difficulty in cleaning the combustion gas side because the smoke tube is bent.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an example in which a swirl tape is inserted into the smoke tube of the boiler of FIG.

FIG. 3 is an example in which the smoke tube of the boiler of FIG. 1 is a spiral projection extruded tube.

FIG. 4 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Upper pipe side 2 Lower pipe side 3 Water pipe 4 Smoke pipe 5 Combustion chamber 6 Burner 7 Combustion gas passage 8 Smoke chamber 9 Precipitation pipe 10 Water pipe 11 Swirl tape 12 Spiral protrusion extrusion pipe

Claims (2)

[Claims] 1. An annular pipe side is provided above and below, a water pipe is provided between a lower end of the upper pipe side and an upper end of the lower pipe side, and a water pipe is provided between the upper end of the upper pipe side and the lower end of the lower pipe side. The smoke pipe provided in the above is inserted, and this water pipe is arranged in an annular shape to form a water cooling wall of the combustion chamber. A burner is provided concentrically with the upper pipe side at the upper part of this combustion chamber, and the smoke pipe is connected to the lower side of the lower pipe side. Providing a passage for combustion gas, providing a smoke chamber leading to the chimney above the upper pipe, and inserting a swirl tape as a heat transfer promoter into the smoke pipe inserted into the water pipe to promote heat transfer of the smoke pipe, As a result, the temperature of the combustion gas is sufficiently lowered by flowing the combustion gas only once in the smoke tube, and the combustion gas can be turned into a boiler exhaust gas. 2. The boiler according to claim 1, wherein said smoke pipe inserted into a water pipe instead of putting a swirl tape into said smoke pipe is a spiral projection extruded pipe which is one kind of heat transfer promoter (processed from outside and spiraled inside). The heat transfer of the smoke tube is promoted as a tube having extruded projections, whereby the temperature of the combustion gas is sufficiently lowered by flowing the combustion gas through the smoke tube only once, so that it can be used as boiler exhaust gas. A vertical smoke tube boiler featuring.