JPH0151731B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a spraying method and apparatus for atomizing and burning a slurry-like fuel such as coal, water, and slurry (hereinafter referred to as CWS). be.

Conventional technology CWS is supplied under pressure to a boiler burner using a pump or the like, and like liquid fuel, it can be atomized and combusted using steam or air as a spray operating gas.

However, since CWS contains a large amount of pulverized coal, uses water as a solvent, and is manufactured by adding several types of additives, it has a high viscosity and is easy to clog the nozzle. It is difficult to atomize due to the influence of the surface tension of
CWS has characteristics that should be taken into account when developing atomizers, such as heating CWS outside of the appropriate temperature range will cause it to aggregate and increase viscosity.

CWS atomizers are still under development, but they can be roughly divided into two types: external mixing type and internal mixing type. and,
It is generally said that the internal mixing type has a better atomization state than the external mixing type.

Therefore, typical examples of the internal mixing type will be explained with reference to FIGS. 5 and 6.

In the figure, 1 is a slurry fuel passage, 2 is an atomizing gas passage, 3 is a fuel outlet, 4 is a flow passage, 5 is a mixing chamber, 6 is an injection nozzle, and 7 is an atomizer. The slurry fuel pumped out from the fuel outlet 3 is combined with the atomizing gas from the atomizing gas passage 2, mixed in the mixing chamber 5, and atomized and ejected from the injection nozzle 6.
Combustion occurs within a combustion chamber. In this internal mixing type, although the structure is complex, it cannot be said that sufficient atomization has been achieved yet.

For this reason, the problems of (1) poor atomization state of CWS and low combustion efficiency, (2) high consumption of spray operating gas used to improve atomization characteristics, and (3) easy clogging. I have it.

Furthermore, although it has been proposed to heat CWS, the purpose is often to lower the viscosity and it has not been able to achieve a sufficient effect.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned problems in CWS atomization, namely, the increase in fuel cost due to poor atomization state of CWS and low combustion efficiency, and to improve the atomization characteristics. This method solves problems such as the need for a large amount of atomizing gas, which increases the cost of atomization, and the complexity of the nozzle structure, which tends to cause blockages due to atomized coal particles. This enables stable continuous operation of CWS combustion,
The aim is to improve the combustion efficiency of CWS and promote its commercial use in small and medium-sized boilers.

Means for Solving the Problems The present invention prevents clogging by making the injection port of the CWS a single hole, and injects a part of the power required to increase the pressure of the CWS toward a target in the mixing chamber and causes the target to collide. By effectively utilizing the splitting and atomizing action, the CWS is already splitting and atomizing, so the subsequent supply of atomizing gas is reduced, and the outer periphery of the target inserted into the mixing chamber is reduced. The above-mentioned problem is solved by further promoting atomization through stirring and collision effects caused by the shape of the particles.

Therefore, the atomizer body is removably connected to the tip of the supply conductor, which has a first passage that is a conduction path for the CWS and a second passage that is a conduction path for the atomizing gas on the outside thereof. To,
A target having a groove-shaped outer periphery, a mixing chamber, a flow path having a single hole in the constriction part communicating with the first passage, and a plurality of flow passages communicating with the second passage and giving a swirling flow in the mixing chamber, and the mixture is atomized. A spray nozzle having a plurality of holes for spraying fuel is provided, and the distance between the target and the constriction part is adjustable and the target is removably screwed into the spray nozzle.

Function The CWS is forced into the CWS conduit and is injected by the throttle part in the form of a single liquid column along the axial direction of the mixing chamber toward the target provided in the center of the mixing chamber, where it collides with the target. Then, by introducing the spray operating gas from the peripheral wall of the mixing chamber in a direction tangential to the wall of the mixing chamber, a spiral mixed flow is formed in the mixing chamber, and Atomization is promoted by the stirring action of the grooves on the outer periphery of the inserted target, and the target is sprayed from the spray nozzle.

Embodiment An embodiment of the present invention will be described based on FIGS. 1 to 4.

Figure 4 shows a CWS supply system applied to the CWS spraying method and device according to the present invention, which includes a CWS tank A, a CWS pressure feeding device B such as a pump, a strainer C, and a flow meter D. and C.W.S.
It consists of an atomizer E, etc. that sprays.

1 and 2 show an atomizer according to an embodiment of the present invention.

This atomizer includes a CWS conduction path 11 provided at the center of the supply conductor 10 to which the CWS from the flowmeter D side is pumped, and a CWS conduction path 11 provided outside the path 11 to which compressed gas from a compressor (not shown) is pumped. A supply conductor 10 consisting of an atomizing gas conduction path 12
, a mixing chamber 15 , a single hole port 13 of the constriction portion that communicates the passage 11 and the mixing chamber 15 , a flow path 14 A and 14 that communicates the passage 12 and the mixing chamber 15 , and a single hole port located at the center of the mixing chamber 15 . The atomizer main body 2 consists of a target 18 provided on the opposite side of the atomizer 13 and a spray nozzle 16 that opens a mixing passage into the furnace 19.
It is mainly composed of 0 and 0.

Then, the single hole port 13 and the flow path 14 of the throttle part
A member 21 equipped with A and a flow path 1 located in front of the member 21
4 and a part of the mixing chamber 15, and a member 23 including the remainder of the mixing chamber 15, the spray nozzle 16, and the target 18 located in front of the atomizer main body 20.
is configured to be detachable from the supply conductor 10 by screwing it onto the supply conductor 10.

The flow passages 14 are arranged in plural directions in such a direction as to form a spiral mixed flow in the mixing chamber by introducing the spray operating gas from the peripheral wall of the mixing chamber 15 in a direction tangential to the wall of the mixing chamber. There are several.

Further, the target 18 is detachably attached to the spray nozzle so that the distance from the constriction part can be adjusted by screwing it into a target mounting screw hole 17 formed in the member 23.
8 is arranged at the center of the member 23, as shown in FIG. 2, and a plurality of spray nozzles 16 are provided at equal intervals around the outer periphery.

Furthermore, as shown in FIGS. 3a, b, and c, the target 18 is composed of a head 18A, a mounting screw part 18B screwed into the target mounting screw hole 17, and a mixing chamber insertion part 18C. 18C
A groove is formed on the outer periphery of the target, and this groove includes a spiral a that is uniform with the spiral of the mounting threaded portion 18B, a spiral b that has a larger pitch than the spiral of the mounting threaded portion 18B, and a plurality of lines c in the axial direction of the target. It is formed by etc.

The CWS in the CWS tank A is passed through a strainer C and a flow meter D by a CWS pressure feeding device B such as a pump.
The CWS is sent to an atomizer E that sprays it, atomized, and sprayed into the furnace 19 for combustion.

The CWS that has passed through the flow rate D is force-fed from the conduction path 11 to the single-hole port 13 of the constriction section, is throttled by the constriction section, and is injected into the mixing chamber 15 as a single high-speed liquid column. The particles collide with the target 18 located at the target 18, and are split into atomized particles due to the action of the collision, resulting in primary atomization. Next, the CWS is given a swirling flow in the mixing chamber by the atomizing gas supplied from the flow path 14 communicating with the atomizing gas conduit 12. When this swirling flow passes through the mixing chamber, it hits the grooves formed on the outer periphery of the target 18 and is vigorously stirred, further promoting atomization, and the atomization is carried out from the spray nozzle 16 into the furnace 19 with sufficient atomization. sprayed onto.

Effects of the Invention According to the present invention, the CWS is sufficiently atomized by splitting and atomizing by collision with the target and atomizing by the swirling flow hitting the grooves formed on the outer periphery of the target. be exposed. Therefore, the supply of the atomizing gas is much smaller than in conventional atomization methods and apparatuses, resulting in high combustion efficiency.

Furthermore, since the CWS is throttled by the constrictor and injected into the mixing chamber as a single high-speed liquid column, the single-hole opening will not become clogged.

Furthermore, since the target is screwed in, CWS
The distance between the slurry and the constrictor can be adjusted depending on the amount of slurry supplied and the state of the slurry.

Furthermore, since the atomizer main body is detachably connected to the supply conductor and the target is screwed in as described above, the inside of the atomizer can be easily cleaned and replaced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an atomizer according to the present invention,
Figure 2 is a front view of the atomizer, Figure 3 is a side view of various targets, Figure 4 is a CWS supply system diagram, Figure 5 is a sectional view of a conventional atomizer, and Figure 6 is another conventional example. 1 shows a cross-sectional view of an atomizer. 10... Supply conductor, 11... Slurry fuel conduit, 12... Atomizing gas conduit, 13... Single hole port, 14, 14A... Channel, 15... Mixing chamber, 1
6...Spray nozzle, 18...Target.

Claims (1)

[Claims] 1. Slurry fuel consisting of a mixture of solid and liquid is pumped into a slurry fuel conduit through a constriction section to a target provided at the center of the mixing chamber along the axial direction of the mixing chamber. The slurry fuel is injected in the form of a single liquid column towards the target, splitting and atomized by colliding with the target, and then the spray operating gas is introduced from the peripheral wall of the mixing chamber in a direction tangential to the wall of the mixing chamber. Spraying of slurry-like fuel, characterized in that a spiral mixed flow is formed in a mixing chamber, and further atomization is promoted by a stirring action by a groove on the outer periphery of the target inserted into the mixing chamber, and then the fuel is sprayed. Method. 2. An atomizer body is removably connected to the tip of a supply conductor, which has a first passage that is a passage for slurry fuel and a second passage that is a passage for atomizing gas on the outside thereof. Inside,
A target having a groove-shaped outer periphery, a mixing chamber, a flow path having a single hole in the constriction part communicating with the first passage, and a plurality of flow passages communicating with the second passage and giving a swirling flow inside the mixing chamber, and the mixture is atomized. and a spray nozzle having a plurality of holes for spraying fuel, the target having an adjustable distance from the constriction part and being removably screwed into the spray nozzle. Fuel atomization device. 3. The slurry fuel spraying device according to claim 2, wherein the groove formed on the outer periphery of the target is a groove extending in the axial direction of the target. 4. The slurry fuel spraying device according to claim 2, wherein the grooves formed on the outer periphery of the target are grooves extending in the radial direction of the target.