JPS635662B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dryer used for drying wet paper.

The cylindrical wet paper paper dryers currently in use can be roughly divided into those made of cast metal and those made of steel plate.

In the steel plate dryer, both the heating cell and the left and right side plates covering the cell opening are formed of steel plates, and the cylinder interior space defined by the heating cell and the side plates is filled with steam to heat the heating cell, It is used to dry the wet paper that is tightly attached to the surrounding area, and this steel plate dryer is widely used because it has better heat transfer properties than cast iron dryers, can be manufactured by sheet metal processing, is lightweight, and is inexpensive. In recent years, in order to improve steam consumption and heat loss, so-called double dryers have become mainstream, in which the outer circumference of the cylinder is double-walled and an annular steam chamber is formed in a limited area along the inner circumferential surface of the heating cell. It's summery. Japanese Patent Publication No. 1983-6644 is cited as a representative example of the double dryer.

As shown in Fig. 1, a cast iron dryer has the heating cell 1 made of cast metal (cast iron), but traditionally, the entire cell, including the cell 1 and side plate 2, is made of cast metal, and the heating cell 1 is made of cast iron. It was common knowledge in the art to create a structure that takes full advantage of the characteristics of castings, which have a small expansion coefficient. For this reason, casting dryers are heavy and
Although its biggest drawback is its high price, on the other hand, there is a strong demand for it because it has the advantage of performance, such as the unique soft paper texture of cast materials that can be dried easily. There is.

Furthermore, as mentioned above, the structural advantage of a cast iron dryer is that the heating cell 1 has little strain, but a characteristic characteristic of cast iron is brittleness (poor tensile strength), and the side plate 2 expands in the radial direction. The thrusting load caused by this is constantly applied to the end of the heating cell 1, causing fatigue to accumulate, and in the worst case, it may lead to breakage or explosion from the same location. Accidents involving casting dryers are caused by breakage and explosion of the water portion near the joint P with the side plate 2.

Therefore, as described below, the applicant made the heating cell a cast metal, effectively taking advantage of the characteristics of a cast iron dryer, and also taking advantage of the advantages of a steel plate dryer (particularly a double steel plate dryer), while at the same time eliminating the disadvantages of both types of dryers. We have developed a new type of wet paper dryer that can completely solve this problem, and that when the heating cell is made of cast metal, the structural assembly with the steel plate structure is designed to effectively prevent damage due to thermal expansion. This led to the development of a commercial dryer.

Hereinafter, the present invention will be explained in detail based on the embodiments shown in FIG. 2 and subsequent figures.

In the figure, numeral 3 indicates a cylinder serving as a casting dryer. The cylinder 3 has a double cylinder structure including an outer cylinder 4 and an inner cylinder 5 arranged concentrically within the outer cylinder 4. The space between the outer cylinder 4 and the inner cylinder 5 is sealed by a side plate 6, and the outer cylinder 4, the inner cylinder 5, and the side plate 6 define an annular steam chamber 7 on the outer periphery of the cylinder.

The outer cylinder 4, which is the outer peripheral wall of the annular steam chamber 7, is made of cast iron and used as a heating cell, and the inner cylinder 5, which is the inner peripheral wall of the steam chamber 7, is made of steel plate. That is, the cylinder 3 is replaced by a cast outer cylinder (heating cell) 4.
It has a double cylinder structure with an inner cylinder 5 made of steel plate.

Furthermore, side plates made of a steel plate are fitted into the left and right openings of the inner cylinder 5 made of a steel plate to cover the opening surfaces, and a curved portion 8a is bent outward at the peripheral end of the side plate 8 made of a steel plate. The curved portion 8a is attached and supported to the inner peripheral edge of the left and right opening ends of the inner cylinder 5, and the ends of the curved portion are welded to the inner cylinder.

Further, as described above, the steel plate side plates 6 for sealing the left and right openings of the annular steam chamber 7 are fitted into the left and right openings between the steel plate inner cylinder 5 and the cast iron outer cylinder 4, and the outer periphery of the steel plate side plates 6 is fitted. The inner circumferential edges of the left and right open ends of the cast outer cylinder are supported at the ends, and the outer circumferential edges of the left and right open ends of the steel plate inner cylinder 5 are supported at the inner circumferential ends of the same side plates. The steel plate side plates 6 are bolted to the outer circumferential surfaces of a flange 20 annularly protruding from the inner circumferential surface of the left and right ends of the outer cylinder 4 and a flange 21 protruding from the outer circumferential surface of the left and right ends of the inner cylinder 5 through bolts or the like. .

For the sake of explanation, the steel plate side plates 8 that cover the left and right opening surfaces of the steel plate inner cylinder 5 are referred to as first side plates, and the steel plate side plates 6 that seal the steam chamber 7 are referred to as second side plates.

In the figure, 9 is a cylinder shaft inserted through the center of the cylinder 3, that is, the center of the first side plate 8, and supplies steam from one end of the shaft 9 to a steam passage 10 bored in the shaft 9. The structure is such that steam is discharged into the annular steam chamber 7 through steam distribution pipes 11 arranged radially from the shaft 9, and in order to make the discharge of steam uniform in the steam chamber 7, from the steel plate inner cylinder 5. A discharge pipe 12 is provided at the end of each pipe 11 projecting into the steam chamber 7 along the outer peripheral surface of the inner cylinder and extending from one side of the steam chamber to the other side (in the width direction).

On the other hand, in order to discharge the drain generated in the annular steam chamber 7, a plurality of buckets 13 are arranged along the outer peripheral surface of the cast outer cylinder 4 in the width direction, and each drain pipe is connected to each bucket 13. 14 are arranged radially from the shaft 9, and are drained to the outside through a drain passage 15 bored toward the other end of the shaft 9.

In addition, a heat insulating material 16 is placed around the inner peripheral surface of the steel plate inner cylinder 5, which has a large contact area with the steam of the annular steam chamber 7, to prevent heat dissipation into the inner cylinder 5, and as shown in the figure. Reinforcement rings 17 are arranged at intervals on the inner circumferential surface of the inner cylinder to provide a rigid structure against the internal pressure of the steam chamber.

As described above, the present invention is a wet paper dryer having an annular steam chamber on the outer periphery of the cylinder, in which the outer peripheral wall defining the annular steam chamber 7 is made of a cast outer cylinder 4, and the inner The peripheral wall is made of a steel plate inner cylinder 5, and the cylinder 3 is made of a cast iron outer cylinder 4 and a steel plate inner cylinder 5.
In addition, as described above, the first side plates 8 made of steel plate are fitted in the left and right openings of the inner cylinder 5 made of steel plate, and the first side plates 8 made of steel plate are fitted in the left and right openings between the inner cylinder 5 and the outer cylinder 4 made of steel plate. The second side plate 6 is fitted so that the annular steam chamber 7 is defined by the cast outer cylinder 4, the steel plate inner cylinder 5, and the second side plate 6, and the second side plate 6 is used to define the annular steam chamber 7. This structure is characterized in that both end edges of the tube 4 and the inner tube 5 are supported, and both end edges of the inner tube 5 are supported by the curved portions 8 of the first side plate made of steel plate.

As mentioned above, the biggest drawback of the cast iron dryer shown in FIG. If applied, it will cause an accumulation of fatigue, and there is a risk of destruction or explosion due to the lack of viscosity peculiar to castings, and the weight is large.
These include high prices.

However, in the present invention, the second side plate 6 comes into contact with the steam only within a limited range of width and area in the radial direction, so that the overall radial expansion coefficient can be suppressed as much as possible.

In addition, the thermal expansion in the radial direction of the second side plate 6 is applied to both ends of the cast outer cylinder 4, which is its fulcrum, and to both ends of the steel plate inner cylinder 5. Since the inner cylinder 5 is made of a relatively elastic steel plate, the second side plate 6
The expansion in the radial direction is absorbed by bending both ends of the steel plate inner cylinder 5 in the direction of the arrow A in the figure, as shown by the arrow A. As a result, the second
Coupled with the fact that the thermal expansion of the side plate 6 is limited,
The cast outer cylinder 4 is not adversely affected by the thermal expansion of the second side plate 6. That is, according to the present invention, thermal expansion in the radial direction of the second side plate 6 is allowed to escape inward, thereby effectively preventing the thermal expansion from being applied to the outside, that is, to both ends of the cast outer cylinder (heating cell) 4.

This effect is made possible by supporting the inside of the inner tube 5 made of a steel plate with the curved portion 8a of the first side plate 8 made of a steel plate. That is, the same effect is a synergistic result of combining the cast outer cylinder 4, the steel plate inner cylinder 5, and the steel plate first side plate 8 and second side plate 6 as in the cylinder structure.

It should be noted that its effectiveness is different from that of the steel plate double dryer disclosed in Japanese Patent Publication No. 54-6644 mentioned above. That is, in the same double dryer, the cylinder side plate is entirely composed of a common base material (steel plate). In such a configuration, even if it partially comes into contact with steam, the entire side plate is subject to expansion due to heat conduction, and although it is possible to considerably suppress the generation of "horns" in the heating cell, which is an issue of the present invention, the above expansion rate is significantly larger than that of the present invention, and most of the expansion is applied to both ends of the heating cell, which is largely different from the above-mentioned effects of the present invention.

While achieving the above-mentioned effects, the present invention can incorporate the characteristics of dry formation that are the advantages of conventional casting dryers, and at the same time solve the problems of high weight and high cost, which are the disadvantages of casting dryers. It also achieves the advantages of heavy dryers, such as reduced steam consumption and improved efficiency, and has extremely great industrial value.

4 and 5 show a case in which a heat storage plate 18 made of metal or the like is provided as a bridge in the annular steam chamber 7 in order to further improve thermal efficiency while incorporating the above embodiment. . Preferably, the heat storage plate 18 is made approximately equal to the width of the steam discharge pipe 12 described above, and is bent into a corrugated shape, and a perforated plate with numerous steam vent holes 19 is used, depending on the implementation. .

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a typical conventional casting dryer, Fig. 2 and subsequent figures show examples of the dryer according to the present invention, Fig. 2 is a sectional view of the same dryer as viewed from the front, and Fig. 3 is the same. A sectional view of the dryer as viewed from the side, FIGS. 4 and 5 show other examples of the dryer, FIG. 4 is a sectional view of the dryer as seen from the front, and FIG. 5 is a sectional view of the dryer as seen from the side. It is. 3... Cylinder, 4... Casting outer cylinder, 5...
Inner cylinder made of steel plate, 6... Second side plate made of steel plate, 7... Annular steam chamber, 8... First side plate made of steel plate, 8a... Recurved portion, 9... Cylinder shaft, 10... Steam passage, 1
DESCRIPTION OF SYMBOLS 1...Steam distribution pipe, 12...Steam discharge pipe, 13...Bucket, 14...Drain discharge pipe, 15...Drain passage, 16...Insulation material, 17
... Reinforcement ring, 18 ... Heat storage plate, 19 ... Steam vent hole, 20, 21 ... Flange.

Claims (1)

[Claims] 1 The dryer cylinder has a double cylinder structure consisting of a cast outer cylinder which is a heating cell, and a steel plate inner cylinder arranged concentrically with the cast outer cylinder, and a steel plate first cylinder is installed at the left and right openings of the steel plate inner cylinder. A side plate is fitted to support the inner peripheral edge of the steel inner cylinder by the curved portion of the outer peripheral edge of the steel plate side plate, and a steel plate is fitted to the left and right openings between the cast outer cylinder and the steel inner cylinder. A second side plate is fitted so that the outer circumferential edge of the second side plate made of steel supports the inner circumferential edge of the cast outer cylinder, and the inner circumferential edge of the second side plate made of steel plate supports the outer circumferential edge of the inner cylinder made of steel plate. A dryer for drying wet paper paper, the dryer having an annular steam chamber formed between the cast outer cylinder and the steel inner cylinder, which are sealed by the second steel side plate.