JPS6221569B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for easily removing dust accumulated in a reactor into which dust-containing gas flows through a curved flow path and the flow direction is changed several times.

It is known that a reactor for removing harmful components such as nitrogen oxides and sulfur oxides contained in dust-containing gas using a catalyst is provided in a gas flow path. In this case, the duct connecting the gas generation source and the reactor becomes complicated and twisted due to the reduction in the installation area of the plant and the arrangement of equipment. For this reason, in the past, in order to prevent uneven flow and reduce pressure loss at the bent part of the duct, three to four fixed rectifying plates were installed along the bent part before the flow into the reactor to ensure an even flow of gas into the reactor. It's like this. In this case, the accumulated dust inside or at the inlet of the reactor is removed when the reactor catalyst is replaced, or a special soot blower is installed.

The object of the present invention is to propose an apparatus that can remove dust even during reactor operation by making use of the uneven flow formation of gas.

In short, this invention provides a gas flow path variation in which a reactor is provided downstream of one or more curved dust-containing gas flow paths, and one or more movable vanes are provided upstream to blow out pressurized gas from the lower edge of the reactor toward the downstream side. It is characterized by being a reactor with equipment.

An embodiment of this invention will be explained with reference to FIG.
FIG. 1 shows a dry denitrification apparatus having a reactor 2 formed of a catalyst such as a plate type or honeycomb catalyst with little pressure loss and little dust accumulation in a duct 1 having a complicated shape.

Generally, when installing a denitrification device by filling an existing flue with a catalyst, the duct has a complicated shape, so a considerably uneven flow of gas flows into the reactor. Since drifting has a large effect on the reduction in the denitrification rate, a baffle plate 3 is generally provided at the inlet of the catalyst layer to make the gas flow uniform.

In this case, fixed blades are generally used as the current plate 3. In such a case, the present invention receives a supply of pressure gas from a pressure gas supply source (not shown) separately provided within the rotating shaft on the upstream side of the reactor 2,
One or more movable vanes 4 which eject a jet of the pressurized gas from the trailing edge are provided to adjust the gas flow so that a uniform flow flows into the reactor 2 during normal operation.

When dust is deposited in the reactor, the movable vane, which can continuously or intermittently eject high-speed gas from its rear edge, is rotated to generate a small vortex in the gas flow and to vary its flow direction.

As a result, the direction of the biased gas flow is changed, and in addition to this, the part with high gas flow velocity changes its position due to the rotation of the movable vane, and the gas flow path divided by the fixed rectifier plate is changed to a high-speed gas flow. move sequentially and have a soot blow effect.

According to the implementation and observation of this invention, it is desirable to adjust the flow velocity so that the flow velocity is 7 m/s or higher in some parts, and the number of movable vanes is such that the high velocity part moves and blows over the entire area of the packed bed. Set it to wet.

Also, as shown in Fig. 2, the rotation axis 7 of the movable vane
High-pressure gas supplied from another pressure supply source (not shown) is ejected from inside to generate a jet jet from the vane trailing edge nozzle 8. In addition to the small vortex formation effect with the normal swirling force of the movable vane 4b, The effect of forming a vortex flow having a strong swirling force due to the jet flow can also be added.

FIG. 3 is a perspective view showing the structure of the movable vane 4b of FIG. 2. In this case, the movable vane has a hollow rotating shaft 7 in the center, and the movable vane has a high pressure gas
VG to flow control valve 11 (shown in FIG. 5) pipe 10,
It is supplied to the inside of the shaft of the tube 10 via the nozzle 10a. This high-pressure gas is ejected from a plurality of holes 7a provided in the rotating shaft, and is ejected as a jet jet from a vane trailing edge nozzle 8 as a high-speed gas flow.
In this case, the high-pressure gas is ejected continuously or intermittently as necessary to form small vortices with strong swirling forces such as v ₀ , v ₁ , and v ₂ as shown in Figure 4, and to change the flow direction. Creates a soot blow effect. The effect of soot blowing does not usually occur because steam is blown directly onto the surface on which dust has accumulated, but the dust is stirred up by the turbulent flow of gas, and the dust accumulated inside the reactor downstream is also removed. is known by the boiler operator through observation. It is understood that otherwise only the boiler tube facing the soot blowing device would have been cleaned.

FIG. 4 shows that v ₀ , v ₁ , v ₂ (v ₀ ′, v ₁ ′, v ₂ ′) have a small vortex in the gas flow direction, and the flow direction changes. The movable vanes 4a and 4b may be operated simultaneously or independently to cause the gas jets to interfere with each other.

Figure 5 is a schematic diagram showing the concept of an example of a high-pressure gas supply device and its control system.
The VG is ejected from the rear edge 8 of the vane via the flow control valve 11, the pipe 10, the rotating shaft 7, and the nozzle 10a.
The timing of the ejection, whether the ejection is continuous or intermittent, the amount of pressurized gas to be supplied, the rotation method of the movable vane, etc. are determined by the control box 12, and the rotation of the lever 13 connected to the flow control valve 11 and the hollow shaft. It can be done under control. The timing of ejection is determined by a timer or by reactor 2.
It is also possible to issue a command to the control box using the gas pressure drop amount as a signal.

By implementing this invention, during normal operation, a uniform gas flow can be obtained on the gas inlet side of the reactor, which has the effect of improving denitrification performance, and pressurized gas can be ejected as necessary to prevent dust accumulation. The dust blowing effect can be achieved by rotating the movable vane, there is no need to provide a special soot blowing device, it is economical, and it is easy to operate.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view including a duct portion according to the present invention, FIG. 2 is a cross-sectional view of a movable vane with a jet jet, FIG. 3 is a perspective view of a movable vane 4b, and FIG. 4 is a movable vane. FIG. 5 is a diagram schematically showing the formation of a small vortex flow in the wake and the flow direction fluctuation, and FIG. 5 is a schematic diagram of the high-pressure gas supply system. DESCRIPTION OF SYMBOLS 1... Duct, 2... Reactor, 3... Fixed current plate, 4, 4a, 4b... Movable vane, 5... Funnel-shaped receiving part, 6... Slit nozzle part, 7...
Rotation axis, 8... Vane trailing edge nozzle.

Claims (1)

[Claims] 1 In a reactor located downstream of one or more curved dust-containing gas flow path, upstream of the reactor,
A gas flow path variation characterized by having one or more movable vanes formed by fixedly connecting a hollow vane with an opening at the downstream trailing edge and a hollow rotating shaft for supplying pressurized gas to the inside thereof. Reactor with equipment.