JPS643957Y2 - - Google Patents

Description

[Detailed description of the invention] The invention is based on waste heat boilers, gas turbine ducts,
This invention relates to a fireproof and heat-insulating structure for ducts that can be used in duct burners and the like.

The first example is a gas turbine waste heat boiler plant.
As shown in the figure. In the figure, 1 is waste gas, 2 is duct, 3
4 is a waste heat boiler, 4 is a refractory insulation material, 5 is an auxiliary combustion burner, 6 is a gas turbine, and 7 is a chimney.

In recent years, the waste gas 1 of gas turbines has been
(600 to 1100°C) is often led through duct 2 and used as a heat source for boiler 3. A fireproof insulating material 4 is attached to the inner surface of the duct 2 to minimize heat loss.
A sudden rise or fall in temperature, that is, a thermal shock is applied to the fireproof insulation material 4.

It is known that conventionally commonly used refractory bricks, castables (unshaped refractories), etc. are relatively weak against the above thermal shock, and the life of the duct 2 is significantly shortened due to cracks developing and falling off. ing. Therefore, in recent years, ceramic fibers have rapidly become popular in the form of bulk, blanket, felt, board, etc. This ceramic fiber has many advantages such as high heat resistance, high thermal shock resistance, low heat conduction, low specific heat, light weight, and low crack occurrence. There are also disadvantages, such as being sexually active.

Therefore, attention is being paid to a method of increasing wind speed resistance by making the fiber direction perpendicular to the duct wall as shown in Figure 2. In the figure, d is the outer wall of the duct, f is the fiber direction, b is the insulation block, m is the module, t is the thickness, and g is the waste gas flow direction.

The above method is characterized in that costs can be reduced by making it into a block of approximately 300 x 300 mm (thickness is arbitrary) and attaching it to the duct wall. However, the wind speed is only around 10 m/s, and the required value for the gas turbine waste heat boiler, etc. is 20 m/s.
~30 m/s is insufficient.

The present invention was developed in an attempt to eliminate the above-mentioned problems of the conventional example, and aims to strengthen the wind speed performance while taking advantage of the advantages of ceramic fiber blocks. The surface of the block is covered with ceramic glass or glass cloth, the overlapping ends of the ceramic glass or glass cloth are sewn together with a glass rope, and the end of the glass rope is placed in contact with the outer wall of the duct for tension adjustment. The present invention provides a fireproof and heat-insulating structure for a duct, which is characterized by being locked to a spring.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 3 and 4.

In FIGS. 3 and 4, reference numeral 11 is a heat insulating block, 12 is an anchor bolt, 13 is a nut, and 14 is a heat insulating block.
is the outer wall of the duct, 15 is ceramic fiber cloth or glass cloth, 17 is anchor bolt, 18 is spring, 19 is glass rope, 20 is knot, 21
2 indicates a fiber presser, and 22 indicates the cloth width.

The heat insulating block 11 is installed on the duct outer wall 14 with anchor bolts 12 and nuts 13. The anchor bolt 12 and the duct outer wall 14 are fixed by welding or screws. The heat insulating block 11 is covered with a ceramic fiber cloth or glass cloth 15.

Ceramic fiber cloth or glass cloth 1
The end portions of 5 are overlapped with adjacent ceramic fiber cloth or glass cloth 15, and then sewn together with glass rope 19 if necessary. On the other hand, the glass rope 19 for fixing the ceramic fiber cloth or glass cloth 15 is tied in advance to the anchor bolt 17 fixed by welding or screws, and the end thereof is taken out and a knot 20 is tied at the overlapping part of the cloth to fix it. . A tension adjustment spring 18 is installed on the anchor bolt 17.

Next, the action and effects will be described.

Ceramic fiber cloth or glass cloth 1
5 is pulled in the plane direction, but it is necessary to prevent vibration (flapping) due to gas wind speed and absorb thermal contraction. For this reason, the spring 18 attached to the bolt 17
Pull it toward the duct outer wall 14 side and fix it.

On the other hand, when gas comes into direct contact with a ceramic fiber block, the fibers may be blown away depending on the wind speed.
By covering the fiber block with ceramic fiber cloth or glass cloth 15, peeling and scattering of the fibers is prevented. The required thickness of the ceramic fiber cloth or glass cloth 15 is determined by the wind speed and its direction.

The ceramic fiber cloth or glass cloth used must have (a) heat resistance, (b) low heat shrinkage, (c) high tensile strength, (d) high wind speed resistance, and (e) low air permeability. Ru.

The present invention can strengthen wind speed resistance, which is a disadvantage of ceramic fibers, and can also maintain a constant insulation thickness, preventing a decline in insulation performance and extending the life of the fireproof insulation material.

Ceramic fiber cloth or glass cloth also shrinks by about 1 to 5% due to heat, but the tension generated in the ceramic fiber cloth or glass cloth can be adjusted by adjusting springs attached to bolts.

The above adjustment spring was installed as close as possible to the outer wall of the duct, and the ceramic fiber cloth or glass cloth was fixed using a glass rope with low thermal conductivity, so it did not create a thermal bridge and did not cause heat loss. On the other hand, since the bolts and adjustment springs do not reach high temperatures, there is an advantage that inexpensive general steel materials can be used.

[Brief explanation of the drawing]

Figures 1 and 2 show conventional heat insulating structures.
Figure 2 is a system diagram of a gas turbine, Figure 2 is a perspective view of a heat insulating structure, Figures 3 and 4 relate to the present invention, Figure 3 is a side view showing the configuration, and Figure 4 is a plan view thereof. 11...Insulation block, 12...Anchor bolt, 13...Nut, 14...Duct outer wall, 15
... Ceramic fiber cloth or glass cloth, 17 ... Anchor bolt, 18 ... Tension adjustment spring, 19 ... Glass rope, 20 ... Knot,
21...Fiber presser fitting, 22...Fabric width.

Claims (1)

[Scope of utility model registration request] The surface of one or more insulation blocks provided on the outer wall of the duct is covered with ceramic glass or glass cloth, and the overlapping ends of these ceramic glasses or glass cloth are sewn together with a glass rope, and the ends of this glass rope are sewn together. is locked to a tension adjustment spring installed in contact with the outer wall of the duct.