JPH10216572A - Spray nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the blocking of a spray device or the like generated by slaked lime slurry, make the maintenance easy and eliminate the necessity of a mixing device for manufacturing slaked lime slurry. SOLUTION: A spray nozzle is formed of the combination of an inner nozzle 2 formed of a double piping forming a central flow path 21 and an outer flow path 22 on the outer periphery of the central flow path 21, in which water of proper pressure is supplied from a water inlet 23 into the outer flow path 22 and sprayed out of an end 24 of the outer flow path 22, and an outer nozzle 3 for jetting slaked lime powder on the periphery of the inner nozzle 2 by pressurized air, and the end of the spray nozzle is mounted by facing the inside of an exhaust gas duct 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention neutralizes hydrogen chloride (HCl) and sulfur oxide (SO _X ) contained in exhaust gas generated from incinerators such as municipal waste, industrial waste and sewage sludge. The present invention relates to a spray nozzle of a supply device for an alkali neutralizing agent used in an exhaust gas treatment facility for removing carbon dioxide, for example, slaked lime.

[0002]

2. Description of the Related Art Conventionally, in order to supply an alkali neutralizing agent such as slaked lime to exhaust gas, a completely dry method shown in FIG. 3 and a semi-dry method shown in FIG. 4 have been used. In the all-dry flow of FIG. 3, after exhaust gas generated from the incinerator 11 is heat-recovered by the heat exchanger 12, dust is removed by the cyclone 13, and fine dust is further removed by the dry EP 15. It is processed in a dry state so that it is released.
By blowing the gas into the duct immediately before 15, the acidic gas components in the exhaust gas, such as hydrogen chloride and sulfur oxide, are neutralized, and the reaction product is separated and removed together with fine dust in the dry EP15. This all-dry neutralization and removal apparatus requires a small facility cost, but has a problem that the acid gas removal rate is low because the reactivity with the acidic gas component is not large.

In the semi-dry flow shown in FIG. 4, the exhaust gas having passed through the cyclone 13 is led to a reaction tower 17, where a prepared slurry of slaked lime and water prepared in advance is sprayed into the tower and brought into contact therewith. Thus, the contained hydrogen chloride and sulfur oxides are neutralized, the reaction products are taken out from the bottom, and the floating products are separated and removed in the bag filter 18 together with fine dust. In this semi-dry type neutralization removal device, although there is an advantage that the reactivity with the acid gas component can be maintained at a large and high removal rate, slaked lime in the slurry is easily transformed into an insoluble solid, for example, calcium carbonate. However, there is a problem that the sediment is deposited and deposited on the slurry pipe, the spraying device and the nozzle to easily cause blockage, and the maintenance is troublesome.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the neutralizing and removing apparatus, and it is intended to prevent the obstruction of a spraying apparatus or the like by a neutralizing agent such as slaked lime slurry, Provided is a spray nozzle having a structure that facilitates maintenance, and further does not require a mixing facility for manufacturing slaked lime slurry.

[0005]

SUMMARY OF THE INVENTION The above problem is caused by a spray nozzle characterized in that an outer nozzle for jetting a dry neutralizing agent by pressurized air is provided around the tip of an inner nozzle for spraying water. Can be solved. Further, an outer nozzle for jetting the dry neutralizing agent by pressurized air is provided around the tip of the inner nozzle for spraying water, and the jetting speed of the jetting particles of the neutralizing agent is determined from the spraying speed of the water spraying particles. It can be further preferably solved by a spray nozzle characterized in that the jet particles of the neutralizing agent are made to collide with the spray particles of water.

[0006]

Next, an embodiment of the present invention will be described with reference to FIG. The spray nozzle of the present invention
It consists of a combination of an inner nozzle 2 for spraying water and an outer nozzle 3 for jetting slaked lime powder as a neutralizing agent. And this inner nozzle 2
Is composed of a double pipe forming a central flow path 21 and an outer flow path 22 located on the outer periphery thereof. Water at an appropriate pressure is fed into the outer flow path 22 from a water supply port 23, and a tip 24 of the outer flow path 22 is formed.
At the outlet, and is sprayed into the duct 4 through which the exhaust gas flows. Excess water is returned from the outlet 25 as return water through the central flow path 21. Such an inner nozzle 2 is a nozzle called a one-fluid spray nozzle or an airless nozzle, and can adjust and change the spray pressure and the spray pattern by controlling the amount of return water.

A feature of the present invention is that an outer nozzle 3 for jetting a dry neutralizing agent such as slaked lime powder by pressurized air around the spray tip of the inner nozzle 2.
The outer nozzle 3 is provided with the outer flow path 31 so as to surround the outer pipe of the inner nozzle 2.
Is formed at the base end, and an inlet 32 for feeding a neutralizing agent
Are provided, and the front end portion is disposed facing the inside of the duct 4 similarly to the front end portion of the inner nozzle 2. In such an outer nozzle 3, the slaked lime powder is fed from the inlet 32 by the compressed air and ejected from the tip, so that the slaked lime powder collides with the spray water generated by the inner nozzle 2 described above. The water droplet and the slaked lime powder can be integrated into a slurry. And
The sprayed water droplets containing slaked lime diffuse widely in the duct 4, so that the reaction with the acid gas is efficiently performed.

In this case, the jetting speed of the neutralizing agent jetting particles by the outer nozzle 3 is made larger than the spraying speed of the jetting water droplets generated by the inner nozzle 2, and the jetting particles of the neutralizing agent are sprayed into the spraying water droplets. It is good to adjust to make it collide. The size of the spray water droplet is usually 80-100 μm.
Although the diameter is about m, the specially-available slaked lime powder, which is generally available, is under 50 μm. Therefore, it is recognized that the larger the ejection speed of the slaked lime powder having a small diameter, the greater the probability of collision of both particles. Was. Controlling the velocities of both particles in this way is particularly preferred in order to obtain a spray droplet containing homogeneous slaked lime.

Here, in the completely dry neutralization and removal apparatus shown in FIG. 3, the case where slaked lime powder is blown from the slaked lime powder tank 14 into the duct immediately before the dry EP 15 and Instead, a comparison was made between the case where spray water containing slaked lime was blown in by the spray nozzle of the embodiment. In this case, the exhaust gas flow rate: 6000
Nm ³ / h, gas temperature: 300 ° C., gas velocity: 20 m /
s, acid gas concentration at cyclone outlet, SO _x : 90p
pm, HCl: 450 ppm.

Under these conditions, a neutralization removal operation was performed, and the concentration of the acid gas remaining at the dry EP outlet was measured.
_x : 63 ppm (30% removal rate), HCl: 225 pp
m (removal rate of 50%), whereas in the case of the spray nozzle of this embodiment, SO _x : 45 ppm (removal rate of 50%)
%), HCl: 90 ppm (80% removal rate),
It can be applied with an excellent removal rate in a completely dry neutralization removal device. In the case of the spray nozzle according to this embodiment, solid matter generated from slaked lime or the like was not found on the nozzle body as well as the related piping, and no clogging phenomenon occurred. In this description, an example is shown in which the spray nozzle of the present invention is applied to the all-dry neutralization / removal device of FIG. 3, but the neutralization reaction tower 17 of the semi-dry neutralization / removal device shown in FIG.
Can be preferably applied.

FIGS. 2A and 2B show another embodiment of the inner nozzle 2 constituting the nozzle of the present invention. In FIG. 2A, the spraying is performed from the opposite direction as compared with the case of the inner nozzle of FIG. 1 described above so that the spray water is supplied to the central flow path 21 and the drainage is performed through the outer flow path 22. 2 (B) is a type in which spray water is supplied to a central flow path 21 and spray air is supplied through an outer flow path 22 to perform a spray action at a tip end portion. Either type of nozzle is well applicable to the present invention.

[0012]

Since the spray nozzle of the present invention is constructed as described above, the slurry of slaked lime does not stay at least in the related pipes and the nozzle body, so that it is caused by slaked lime in the slurry. Solids are plumbing,
It does not settle and deposit on the spraying device and nozzle, and of course does not cause blockage. Therefore, there is an effect that no maintenance is required. In addition, there is no need for a mixing facility for producing slaked lime slurry, and there is an excellent effect that it can be applied to a semi-dry type as well as an all-dry type neutralization removing device. Therefore, the present invention has a very large industrial value as a spray nozzle which has solved the conventional problems.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view for explaining a use state of a spray nozzle of the present invention.

FIG. 2 is a schematic sectional view showing another example of the inner nozzle of the spray nozzle of the present invention.

FIG. 3 is a flowchart showing a main part of the all-dry neutralization removing device.

FIG. 4 is a flowchart showing a main part of a semi-dry neutralization removing device.

[Explanation of symbols]

2 inner nozzle, 21 center flow path, 22 outer flow path, 23 inlet, 24 tip, 3 outer nozzle, 3
1 Outer channel, 32 inlets, 4 ducts.

Claims (2)

[Claims] 1. A spray nozzle comprising an outer nozzle for spraying a dry neutralizing agent by pressurized air around a tip of an inner nozzle for spraying water. 2. An outer nozzle for jetting a dry neutralizing agent by pressurized air is provided around the tip of an inner nozzle for spraying water, and the jetting particles of the neutralizing agent are determined based on the spray speed of the water spray particles. A spray nozzle characterized in that the spray speed of the neutralizing agent is increased by increasing the spray speed of the neutralizing agent.