JPS6344663Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a chimney that prevents corrosion of the chimney base material. Conventionally, in order to prevent corrosion of the chimney base material such as iron due to the passage of humid gas containing corrosive substances through the chimney, a corrosion-resistant protective lining plate has been lined on top of the base material. It is. However, normally the lining of the protective lining board is
This is done by using multiple protective lining plates by welding or other adhesive means, so moisture that rises inside the chimney from incomplete or damaged parts such as welded parts over time. A phenomenon that corrosive substances in the gas invade and corrode the chimney base material often occurs. In particular, corrosive substances in the humid gas get mixed up in the condensate that condenses and adheres to the inner wall of the chimney, and the condensate enters the gap between the chimney base material and the protective lining plate through cracked welds, etc., and damages the chimney. This often causes corrosion of the base material. The present invention has been made to prevent such a phenomenon. That is, the present invention provides a chimney in which a chimney base material is lined with a protective lining plate, in which a non-corrosive gas is applied to the base material in the gap between the base material and the protective lining plate. This is a chimney in which the gas is press-fitted and maintained so that the pressure of the gas is 0.01 atmosphere or more and 0.3 atmosphere or less higher than the average internal pressure inside the chimney. By adopting such an aspect, it is possible to prevent corrosive substances from entering through the missing portions of the welded portions of the protective lining plate, accompanied by drains, etc. In the present invention, a chimney refers to a stack that releases humid gas into the atmosphere, and is a concept that also includes a flue portion. FIG. 1 shows one of the representative embodiments of the present invention,
It is shown by a sectional view of a chimney. That is, in the chimney 1 , a chimney base material 2 is lined with a protective lining plate 3, and a gap 4 is provided between the chimney base material 2 and the protective lining plate 3. For example, the connection pipe 5 is passed from the pressure tank 6 into the gap 4, and the chimney base material 3 is
A non-corrosive gas is injected under pressure. Note that the present invention can also be applied to a portion commonly referred to as the so-called flue 7. The materials used for the chimney base material 2 and the protective lining plate 3 may be those commonly used as they are. For example, the chimney base material 2 is typically made of iron, and the protective lining plate 3 is made of stainless steel, titanium, etc., and if the temperature of the wet gas passing through the chimney is relatively low, fiber-reinforced plastic, etc. can also be used. The form of the lining of the protective lining plate 3 is not particularly limited. Ideally, one large cylindrical protective lining plate should be used to reduce the number of welded parts where defects are likely to occur, but this is not possible in practice. Therefore, the lining of the protective lining plate 3 as shown in FIG. 1 is constructed using a considerable number of curved protective lining plates. In the present invention, since gas is pressurized into the gap 4 between the chimney base material 2 and the protective lining plate 3, it is necessary to have a gap 4 suitable for the gas injection. However, it is sufficient that the gap is large enough to allow the pressurized gas to flow, and the chimney base material and the protective lining plate are not necessarily separated by a certain distance. It is not required. For example, when a protective lining plate is stacked on top of a chimney base material in a normal state, the presence of a small gap between the two prevents the flow of injected gas.
It is possible. Generally, it is preferable to provide a gap of about 2 to 3 mm, as this allows for smoother flow of the injected gas. In the present invention, as shown in FIG. 1, when the entire gap 4 between the chimney base material 2 and the protective lining plate 3 is communicated, there is an advantage that only one gas injection port is required. FIG. 2 shows an alternative embodiment of the invention. That is, the gap 4 between the chimney base material 2 and the protective lining plate 3 is divided into a plurality of independent sections. In this embodiment, for example, a curved protective lining plate having a length slightly longer than about a quarter of the inner circumference of the chimney is used, and the inner walls of the two chimney base materials are first lined in close contact with and opposed to each other. The two inner protective lining plates are connected by partially overlapping both ends of the two inner protective lining plates, and the two separate protective lining plates are placed opposite each other and first brought into close contact with the inner wall of the chimney. It can be constructed by lining the chimney by lifting it from the inner wall of the chimney by the thickness of the protective lining board. In this way, when the gap is divided into multiple sections and each section is made independent,
Normally, a mechanism is required to pressurize gas into each compartment, but in addition to ensuring that condensate that has entered one compartment does not infiltrate other compartments, the pressure state of the injected gas in each compartment can be measured to prevent welding points, etc. This is also preferable since it can be expected to have the effect of being able to accurately discover the location of a complete or missing portion. In addition, in the embodiment in which the above-mentioned protective lining plates 2 are lined two by two facing each other, the length of the curved protective lining plate that is brought into close contact with the inner wall of the chimney base material is slightly shorter than about one-fourth of the inner circumference of the chimney. On the other hand, by setting the length of the curved protective lining board floating above the inner wall of the chimney base material to a certain extent longer than about one-fourth of the inner circumference of the chimney, it is also possible to connect the once-divided gap. . In this embodiment, for example, the upper side of the protective lining plate is formed in an upwardly concave shape to prevent the condensate from entering other compartments by storing some of the condensate that has entered the concave part, and also to prevent the condensate from entering other compartments. It is not necessary to provide each section, which is one of the most preferred aspects of the present invention. Note that it is recommended that the collected drain be taken out to the outside by providing an appropriate outlet. The gas to be pressurized may be any gas that is substantially non-corrosive to the chimney base material, and for example, air, nitrogen, etc. are preferably used. Of course, it is not preferable to use a gas that corrodes the protective lining plate. Further, the pressure within the gap of the injected gas may be any pressure that can substantially prevent drainage from entering through the defective portion, etc., if a defective portion or the like occurs. That is, the pressure of the injected gas in the gap usually needs to be higher than the average internal pressure in the chimney by 0.01 atmosphere or more, preferably by 0.05 atmosphere or more. Also, if the pressure is too large, it may have a negative effect on the protective lining plate, so from this point of view,
The pressure of the injected gas must be kept at most 0.3 atmospheres higher than the chimney internal pressure. For this purpose, it is preferable to link the internal pressure in the chimney and the pressure of the injected gas. To pressurize the gas, as described above, for example, the pressure tank 6 may be installed, and pressurized gas may be fed into the pressure tank 6 using a blower, a compressor, or the like. If a defect occurs over time at the welded portion of the protective lining plate and the pressure of the injected gas decreases, it is advisable to increase the gas pressure in the pressure tank as appropriate. Furthermore, in addition to the mode in which the pressure of the injected gas is maintained at a predetermined constant desired pressure, it may be effective in some cases to maintain the pressure intermittently at two levels of high and low pressures. As understood from the above explanation, the present invention is
By injecting gas into the gap between the chimney base material and the protective lining plate, the intrusion of corrosive substances accompanying drainage and other substances is prevented, and the corrosion of the chimney base material, which has been a problem in the past, is prevented. This effectively prevents trouble. Examples and Comparative Examples: Chimney with inner wall base material made of iron and stainless steel thickness 2
First, line two protective lining plates of mm in length, each slightly shorter than about a quarter of the inner circumference of the chimney, facing each other in close contact with the inner wall of the chimney. Place two other protective lining plates that are slightly longer than about a quarter of the inner circumference of the chimney, partially overlapping each other, facing each other, and lift them up from the inner wall of the chimney by the thickness of the protective lining plates that were lined with each other. I lined it. Next, above the tip of the chimney of the floating protective lining plate, line it with two pieces slightly shorter than about a quarter of the inner circumference of the chimney, facing each other in close contact with the inner wall of the chimney. Two other protective lining plates, each slightly longer than about a quarter of the inner circumference of the chimney, were lined by partially overlapping both ends of the protective lining plate lined with the inner wall of the chimney and floating from the inner wall of the chimney. In this way, the chimney was sequentially lined with protective lining plates from the base to the tip, so that all the gaps between the protective lining plate and the inner wall of the chimney, which had been separated, were communicated. In addition, a hole with a diameter of 12 mm was drilled into each of the five protective lining plates that were lined floating above the inner wall of the chimney. Next, smoke is passed through the chimney, and the internal pressure inside the chimney is measured at 7 locations, and the internal pressure within the gap between the protective lining plate and the inner wall of the chimney is measured at 3 locations, and the difference between the average internal pressure of the chimney and the internal pressure of the gap is measured using a computer. Then, using a pressure control device linked to the computer, air is forced into the gap between the protective lining plate and the chimney inner wall from the bottom of the chimney, and the internal pressure in the gap is 0.005, 0.008, 0.01, 0.05 atmospheres higher than the average internal pressure in the chimney. The condition was maintained for 5 days so that the leakage of condensate into the gap was examined. To determine the leakage situation, a drain receiver was installed directly below the hole in the protective lining plate, and the drain collected in the drain receiver was sucked through a pipe, and the total cumulative amount of drain sucked from the five holes was determined. . The results are shown in Table 1. After that, the five holes in the protective lining plate were closed using the same material as the protective lining plate, so that the internal pressure in the gap between the protective lining plate and the chimney inner wall was 0.3, 0.5, and 0.8 atmospheres higher than the average internal pressure in the chimney. 3 each
The condition of the protective lining plate was observed after holding it for several days and stopping the smoke flow each time. As a result, no abnormality was observed at 0.3 atm, but at 0.5
In the case of atmospheric pressure, the protective lining plate suspended from the chimney and lined inside will be slightly deformed, and in the case of 0.8 atmospheric pressure,
A portion corresponding to 21% of the total area of the protective lining plate protruded by 3.7 mm and was deformed. 【table】

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing typical embodiments of the present invention. 1 is a chimney, 2 is a chimney base material, 3 is a protective lining plate, 4 is a gap, 5 is a connecting pipe, 6 is a pressure tank, and 7 is a flue.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a chimney in which a chimney base material is lined with a protective lining plate, a gas that is non-corrosive to the base material is present in the gap between the base material and the protective lining plate. A chimney characterized in that the non-corrosive gas in the gap is press-fitted and maintained so that the pressure is 0.01 atmosphere or more and 0.3 atmosphere or less higher than the average internal pressure within the chimney. (2) The chimney according to claim 1, wherein the gap between the base material and the protective lining plate is divided into a plurality of sections, and a non-corrosive gas is pressurized into each section.