JPH0435699Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a furnace bottom structure that absorbs thermal stress at the bottom of a coal-fired boiler or the like.

[Prior Art] In a coal-fired boiler or the like, a hearth surround hopper made of a refractory is usually provided at the bottom of the furnace to receive the high-temperature cleaning force discharged from the inside of the furnace. In addition, in coal-fired boilers, etc., the furnace wall is made up of water tubes, and water flows through the hearth bottom tube, so there is an elongation between the hearth tube and the hearth surrounding hopper due to the temperature difference. Differences occur vertically and horizontally.

Therefore, in the past, slits were inserted into the hopper to absorb the difference in elongation due to temperature differences.

[Problems to be solved by the invention] However, in the conventional method of absorbing the elongation difference between the furnace bottom tube and the furnace bottom hopper by simply inserting a slit in the furnace bottom hopper, thermal stress The absorption capacity was not sufficient. Therefore, there was a problem in that excessive force was applied to other parts.

Therefore, the present invention aims to provide a boiler bottom structure that can sufficiently absorb thermal stress without applying excessive force to other parts.

[Means for Solving the Problems] In order to achieve the above object, the present invention integrally connects an upper casing with a deck plate structure lined with a refractory material and a lower casing lined with a refractory material by an expansion. The furnace bottom hopper is connected to the hearth tube, and has joints provided at positions corresponding to the expansion of the refractory and at appropriate intervals in the circumferential direction along the upper casing.

[Function] When thermal stress acts between the hearth bottom tube and the hearth bottom surrounding hopper, the difference in elongation in the vertical direction is absorbed by the expansion, and the difference in elongation in the front, back, left and right directions is absorbed by the upper casing with the deck plate structure. be done.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a furnace, 2 is a bottom tube of the furnace 1, and 3 is a furnace connected to the lower part of the bottom tube 2 and configured to absorb thermal stress. The bottom circumference is hoppa.

The hearth surrounding hopper 3 is constructed as shown in FIGS. 2 and 3. In other words, the hearth hopper 3 is
An upper casing 4 having a deck plate structure around the entire periphery, a lower casing 5 having a flat structure around the entire periphery, and an annular expansion 6 having a U-shaped cross section that integrally connects the upper and lower casings 4 and 5. , and a refractory 7 attached to the inner surfaces of the upper and lower casings 4 and 5, respectively, and the refractory 7 has a position corresponding to the expansion 6 and an upper casing 4.
Joints 8 are provided at appropriately spaced positions in the circumferential direction along the upper casing 4 and the refractory 7 within the expansion 6 and the deck plate structure.
The structure is such that a high temperature fibrous heat insulating material 9 is filled in the gaps between the two. Note that 10 is a support member attached between the lower casing 5 and the furnace bottom tube 2 so as to maintain the position of the lower casing 5.

Now, if there is a difference in vertical elongation between the furnace bottom tube 2 and the furnace bottom hopper 3, the upper casing 4
and the lower casing 5.
This difference in elongation can be absorbed by the flexural deformation of This can be absorbed by the elastic deformation of the deck plate structure. At this time, the position corresponding to the expansion 6 above,
In addition, joints 8 are provided in the refractory material 7 at appropriate intervals along the upper casing 4 in the circumferential direction, so that the expansion 6 and the upper casing 4 can be freely displaced without being restricted. Furthermore, the presence of this joint 8 prevents the refractory material 7 itself from being damaged. In addition, since a high-temperature fibrous heat insulating material 9 is filled in the expansion 6 and between the upper casing 4 and the refractory 7, the high-temperature gas in the furnace 1 directly flows into the upper and lower casings 4 and 5. It can prevent contact with

In the above embodiment, only the upper casing 4 of the hearth surrounding hopper 3 had a deck plate structure.
It goes without saying that the lower casing 5 may also have a deck plate structure, and various other changes may be made without departing from the gist of the present invention.

[Effects of the invention] As described above, according to the bottom structure of the boiler of the invention, the following excellent effects can be achieved.

() The furnace bottom hopper is configured so that it can be moved vertically by expansion, and in the front, rear, left, and right directions by the upper casing with a deck plate structure, so that the heat between the furnace bottom tube and the furnace bottom hopper is displaceable. Stress can be absorbed without applying undue force to other parts.

() Joints were provided in the refractories in the displacement absorbing parts of the expansion and upper casing.
The upper and lower casings can be freely displaced, and damage to the refractory itself can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic view showing the bottom structure of the boiler of the present invention, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 3 is a view taken along the - arrow in FIG. DESCRIPTION OF SYMBOLS 1... Furnace, 2... Hearth bottom tube, 3... Hearth surrounding hopper, 4... Upper casing, 5... Lower casing, 6... Expansion, 7... Refractory, 8
... joint.

Claims (1)

[Scope of utility model registration request] An upper casing with a deck plate structure lined with refractory material and a lower casing lined with refractory material are integrally connected by expansion.
A furnace bottom structure for a boiler, characterized in that a furnace bottom surround hopper is connected to a furnace bottom tube, with joints provided at positions corresponding to the expansion of the refractory and at appropriate intervals in the circumferential direction along the upper casing.