JP5749203B2 - Temperature reduction tower - Google Patents

Description

  The present invention relates to a temperature reducing tower.

  Conventionally, for example, in a waste incineration facility, a temperature reducing tower for cooling gas is used for the purpose of preventing the production of dioxins. In the temperature reducing tower, the temperature is lowered by evaporating the droplets by spraying the droplets on the gas flowing in the tower (see, for example, Patent Document 1).

JP 2001-343115 A

  However, in the above-described temperature reducing tower, there is an increased possibility of drift due to the gas flow path when the gas is supplied to the inside. For example, when uneven flow occurs, there may be a region where gas cooling cannot be sufficiently performed according to the uneven gas flow rate. Also, due to the vortex formed in the region outside the main flow of gas inside the temperature-decreasing tower, the droplet sprayed from the nozzle is insufficiently evaporated, and the droplet mixes with the dust in the tower. There is a risk that the cooling performance of the temperature reducing tower will deteriorate due to adhesion to the inner wall of the temperature reducing tower.

  This invention is made | formed in view of the above, and aims at provision of the temperature reduction tower which can suppress the fall of cooling performance.

  In order to achieve the above object, a temperature reducing tower according to the present invention has a cylindrical shape and is a temperature reducing tower for cooling the gas flowing into the interior from the introduction pipe, and the introduction pipe is connected to the side surface. Provided between the introduction part and the trunk part provided on the downstream side of the introduction part, the trunk part having a channel area larger than the introduction part in a plane perpendicular to the axial direction of the temperature reducing tower. An enlarged portion that expands so that the flow path area increases as it goes from the introduction portion to the trunk portion, and a nozzle that is provided in the trunk portion and sprays liquid droplets on the gas, and reduces the inner surface of the enlarged portion. The angle formed with the axis of the warm tower is characterized in that the side of the side facing the side where the introduction pipe is provided is larger than the side of the introduction where the introduction pipe is provided.

  In the above-described temperature reducing tower, the gas introduced from the introduction pipe into the introduction portion flows downstream by forming a main flow of the gas flow on the opposite side of the introduction pipe with respect to the axis of the temperature reduction tower. At this time, it is the present invention that a vortex is formed between the inner surface of the enlarged portion on the introduction pipe side and the main flow of the gas flow, and this vortex prevents evaporation of droplets and leads to a decrease in cooling performance in the temperature reducing tower. They discovered. Therefore, as in the above-described temperature reducing tower, the angle formed by the inner surface of the enlarged portion and the axis on the side surface provided with the introduction tube is the angle of the enlarged portion on the side surface facing the side surface provided with the introduction tube. By making it larger than the angle formed by the inner surface and the axis, it is possible to suppress the generation of vortex near the inner surface of the enlarged portion on the introduction tube side. As a result, it is possible to suppress a decrease in cooling performance due to a large vortex formed by the drift.

  Here, as an effective configuration of the above embodiment, specifically, the inner surface of the enlarged portion is continuous with the first inclined portion provided on the introduction portion side and the downstream side of the first inclined portion. And an angle formed between the first inclined portion and the axis of the temperature reducing tower is smaller than an angle formed between the second inclined portion and the axis of the temperature reducing tower. .

  ADVANTAGE OF THE INVENTION According to this invention, the temperature reduction tower which can suppress the fall of cooling performance is provided.

It is a schematic block diagram explaining a temperature reduction tower. It is sectional drawing along the axis line X of the temperature reduction tower which concerns on this embodiment. It is sectional drawing corresponding to FIG. 2 of the temperature reduction tower which concerns on a modification. It is IV-IV sectional drawing of the temperature reduction tower of FIG. It is sectional drawing corresponding to FIG. 4 explaining the example which changed the shape of the inner surface of a temperature reduction tower.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram illustrating a temperature reduction tower. FIG. 2 is a cross-sectional view along the axis X of the temperature reducing tower according to the present embodiment.

  The temperature-decreasing tower 1 shown in FIG. 1 suppresses the generation of dioxins by rapidly cooling the high-temperature gas flowing through the tower, and is mainly provided at the rear stage of the incinerator in a waste incineration facility or the like. It is used for the treatment of exhaust gas from incinerators. The temperature reducing tower 1 has a cylindrical shape and is installed in a bowl shape so that its axis X extends in the vertical direction. The temperature reducing tower 1 includes an introduction part 10, an introduction pipe 11, an enlarged part 20, a body part 30, a nozzle 31, an exhaust gas outlet pipe 32, and a discharge pipe 33. Among these, the introduction part 10, the enlargement part 20, and the body part 30 form a gas flow path inside the temperature-decreasing tower 1, and the introduction pipe 11 is used for supplying gas to the inside of the temperature-decreasing tower 1. It is piping. The exhaust gas outlet pipe 32 is a pipe for discharging the gas that has circulated inside the temperature reducing tower 1, and the discharge pipe 33 is a pipe for discharging residues such as dust from the temperature reducing tower 1 as appropriate. is there. In addition, since the inner surface of the region where the gas flows in the temperature reducing tower 1 becomes high temperature, it is formed of a so-called refractory material such as a refractory caster.

  The introduction part 10 provided above the temperature reducing tower 1 has a cylindrical shape and is the most upstream in the gas flow path inside the temperature reducing tower 1. The introduction part 10 is closed at the upper end and has a so-called bottomed cylindrical shape.

  An introduction pipe 11 that introduces gas into the introduction unit 10 is provided on a side surface of the introduction unit 10. The introduction pipe 11 communicates with the inside of the introduction section 10 and extends in a direction intersecting the axis X of the temperature reducing tower 1.

  The expansion part 20 is provided below the introduction part 10, that is, downstream from the introduction part 10 so as to be continuous with the introduction part 10. As shown in FIG. 2, the enlarged portion 20 has the same inner diameter as that of the introduction portion 10 at the upstream end. Therefore, the flow passage area on the surface perpendicular to the axis X at the upstream end of the enlarged portion 20 is the same as that of the introduction portion 10. And as it progresses from the portion connected to the introduction part 10 to the downstream side, the inner diameter gradually increases with the axis X as the center, and the flow passage area in the plane perpendicular to the axis X expands gradually. Yes.

  The trunk portion 30 has a so-called bottomed cylindrical shape that is provided continuously to the enlarged portion 20 below the enlarged portion 20, that is, on the downstream side of the enlarged portion 20, and has a closed bottom surface serving as an end portion on the downstream side. There is no. The trunk portion 30 has a cylindrical shape, and the cross-sectional area in a plane perpendicular to the inner diameter and the axis X is the same as the downstream end portion of the enlarged portion 20.

  An exhaust gas outlet pipe 32 and a discharge pipe 33 are provided at the lower end of the body 30, that is, at the downstream end of the gas flow path inside the temperature-decreasing tower 1. The exhaust gas outlet pipe 32 is a pipe that communicates with the inside of the temperature reducing tower 1 and discharges the gas that has passed through the inside of the temperature reducing tower 1. Moreover, the discharge pipe 33 is provided in the bottom part of the trunk | drum 30 of the temperature decreasing tower 1, and is connected in order to discharge | emit residues, such as dust, suitably.

  The nozzle 31 has a function of spraying droplets on the gas flowing through the body 30 of the temperature reducing tower 1. A plurality of nozzles 31 are attached to the inner surface near the upper end of the body part 30 below the enlarged part 20 and are attached to the inside of the body part 30 so as to spray droplets. From the nozzle 31, for example, fine particles of cooling water are sprayed.

  Here, the shape of the enlarged portion 20 that characterizes the temperature reducing tower 1 of the present embodiment will be further described. The enlarged portion 20 has an asymmetric inner surface in the cross section along the axis X of the temperature reducing tower 1. Specifically, as shown in FIG. 2, the side surface on which the introduction pipe 11 is provided in a cross section including the axis X of the temperature reducing tower 1 and the axis Y of the introduction pipe 11 at the connection position to the introduction section 10. An angle (inclination angle) formed between the inner surface 21 on the side and the axis X is an angle A, and an angle formed between the inner surface 22 on the side (opposite surface side) facing the side surface on which the introduction tube 11 is provided and the axis X. Assuming that the (tilt angle) is an angle B, a relationship of “A <B” is established. That is, the inclination angle of the inner surface 21 on the introduction tube 11 side is smaller than the inclination angle of the inner surface 22 on the opposite surface side.

  In the above-described temperature reducing tower 1, high-temperature gas is introduced into the introduction unit 10 from the introduction pipe 11 provided on the side surface of the introduction unit 10. Then, the gas flow is changed from the lateral direction in the drawing to the downward direction in the introduction part 10 in the temperature reducing tower 1 and passes through the introduction part 10, the expansion part 20, and the trunk part 30. Here, droplets are sprayed from the nozzle 31 into the temperature reducing tower 1. At this time, the droplet sprayed from the nozzle 31 evaporates inside the temperature-decreasing tower 1, whereby the internal gas temperature rapidly decreases due to the heat of vaporization, and the gas that has decreased to a predetermined temperature or less is discharged from the exhaust gas outlet pipe 32. It is discharged outside the temperature reducing tower 1.

  At this time, in the temperature reducing tower 1 according to the present embodiment, a gas drift occurs due to a change in the gas flow direction in the introduction unit 10. Specifically, as shown in FIG. 1, the main flow L of the gas supplied from the introduction pipe 11 into the introduction section 10 does not go vertically downward along the axis X, but the axis X of the temperature reducing tower 1. On the other hand, it flows on the opposite side to the introduction pipe 11. This drift is more conspicuous as the gas flow rate from the introduction pipe 11 is larger, and the main flow is directed to the vicinity of the inner surface on the side opposite to the introduction pipe 11.

  Further, since the enlarged portion 20 provided below the introduction portion 10 has a shape in which the inner diameter increases outward as it goes downstream, the vicinity of the inner surface on the lower side of the enlarged portion 20 and its In the vicinity of the upper inner surface of the lower body portion 30, that is, in the vicinity of the position where the nozzle 31 is provided, vortex flows (vortex flows P and Q in FIG. 1) due to the gas deviating from the main flow L are formed.

  Here, when a gas drift occurs in the introduction portion 10, the magnitude of the vortex formed below the enlarged portion 20 differs between the introduction tube 11 side and the opposite surface side. Specifically, when the main flow L of gas flows downward on the side opposite to the introduction pipe 11 side, the vortex flow formed in the vicinity of the nozzle 31 provided on the opposite surface side opposite to the introduction pipe 11 side. P is reduced, and the vortex Q formed near the nozzle 31 on the introduction pipe 11 side is increased. When a droplet is sprayed from the nozzle 31 in a state where such a gas flow is formed, a part of the droplet moves on the vortex P and Q and moves in the temperature reducing tower 1.

  At this time, since the vortex flows P and Q circulate between the upper portion of the trunk portion 30 and the enlarged portion 20, the droplets riding on the vortex flows are difficult to evaporate. In particular, since the vortex Q formed in the vicinity of the nozzle 31 on the introduction pipe 11 side is a large flow, the ratio of the droplets that move on the vortex Q in the temperature reducing tower 1 increases. In addition, since the vortex is formed on the inner surfaces of the enlarged portion 20 and the body portion 30, there is a high possibility that the droplets riding on the vortex flow adhere to the inner surface of the temperature reducing tower 1. If a droplet adheres to the inner surface of the temperature-decreasing tower 1, the temperature in the vicinity of the droplet drops, so that evaporation of the droplet is inhibited. Further, when the droplets are difficult to evaporate and mixed with dust, they easily adhere to the nozzle 31 and the inner surface in the vicinity thereof. Thus, the large eddy current formed near the inner surface on the introduction pipe 11 side hinders the evaporation of droplets from the nozzle 31, and as a result, the cooling performance of the gas in the temperature reducing tower 1 may be lowered. It was.

  Therefore, in the temperature reducing tower 1 of the present embodiment, as shown in FIG. 2, in the enlarged portion 20, the inclination angle A of the inner surface 21 on the introduction pipe 11 side opposite to the side where the drift is generated is opposed to By making it smaller than the inclination angle B of the inner surface 22 on the surface side, the vortex formed by branching from the main flow is reduced. By reducing the eddy current, it is possible to reduce the number of droplets circulating on the eddy current, and as a result, it is possible to suppress the adhesion of dust to the nozzle 31 and its vicinity.

  Regarding the relationship between the inclination angle of the inner surface 21 on the introduction tube 11 side and the inner surface 22 on the opposite surface side for suppressing vortex flow, the size of the temperature reducing tower 1, the flow rate of gas from the introduction tube 11, the introduction unit 10, and the expansion Since it depends on the shape and the like of the part 20 and the body part 30, it is preferable to select appropriately using a fluid flow simulation of the gas flow.

  Next, a modified example of the temperature reducing tower according to the present embodiment will be described. As described above, in the temperature reducing tower according to the present embodiment, the inclination angle of the inner surface on the introduction tube 11 side in the enlarged portion 20 is made smaller than the inclination angle on the opposite side (opposite side surface side), thereby A structure that suppresses the formation of vortex flow diverging from the mainstream. That is, it is important to change the shape of the inner surface on the introduction tube 11 side so that a large vortex is not formed near the inner surface on the introduction tube 11 side in the enlarged portion 20. Here, as a modification, in the cross section including the axis X of the temperature reducing tower 1 and the axis Y of the introduction pipe 11, the inner surface of the enlarged portion 20 on the introduction pipe 11 side is the first inclined portion 23 and the second inclined portion 24. The structure formed by the above will be described. FIG. 3 is a cross-sectional view corresponding to FIG. 2 of the temperature reducing tower according to the modification, and FIG. 4 is a cross-sectional view taken along the line IV-IV of the temperature reducing tower shown in FIG. Moreover, FIG. 5 is sectional drawing corresponding to FIG. 4 which shows the example which changed the shape of the inner surface of a temperature reduction tower.

  As shown in FIG. 3, in the temperature reducing tower according to the modification, the inner surface of the enlarged portion 20 on the introduction pipe 11 side is provided with a first inclined portion 23 provided on the introduction portion 10 side and a downstream of the first inclined portion 23. It is comprised by the overhang | projection part 25 formed with the 2nd inclination part 24 provided so that it might continue in a side. At this time, the connection part of the 1st inclination part 23 and the 2nd inclination part 24 becomes the shape which protruded toward the axial direction of the inner surface. When the angle formed between the first inclined portion 23 and the axis X is C and the angle formed between the second inclined portion 24 and the axis X is D, the relationship of “C <D” is established. By setting it as such a structure, the inner surface by the side of the introductory pipe 11 in the expansion part 20 is brought close to the axis X side, and formation of the big eddy current below the introductory pipe 11 can be suppressed.

  As shown in FIG. 3, the overhanging portion 25 formed by the first inclined portion 23 and the second inclined portion 24 shown as a modified example is provided with an overhanging portion 25 on the inner surface forming the enlarged portion of the conventional temperature reducing tower. It can be formed by fixing a refractory for forming. Therefore, it is easy to modify the conventional temperature reduction tower in which the shape of the inner surface of the enlarged portion 20 is symmetrical regardless of the position of the introduction pipe 11.

  4 is a cross-sectional view taken along the line IV-IV in FIG. When viewed from above along the axis X, as shown in FIG. 4, a linearly projecting portion 25 is formed so as to cut out a part of the inner periphery of the enlarged portion 20 corresponding to the introduction tube 11. Alternatively, as shown in FIG. 5, the inner periphery on the introduction tube 11 side may be formed in a curved shape so as to be divided into arcuate shapes.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to the said embodiment, A various change can be performed.

  For example, in the above-described embodiment, the overhang portion formed by two inclined portions provided so that the inner surface of the enlarged portion on the introduction pipe 11 side is continuous has been described. However, the shape of the overhang portion has a large channel area. It can change suitably in the range of the shape expanded so that it may become.

DESCRIPTION OF SYMBOLS 1 ... Temperature reduction tower, 10 ... Introduction part, 11 ... Introduction pipe, 20 ... Expansion part, 21,22 ... Inner surface, 23 ... 1st inclination part, 24 ... 2nd inclination part, 30 ... Body part, 31 ... Nozzle.

Claims (2)

A temperature reducing tower for cooling the gas flowing into the interior from the introduction pipe having a cylindrical shape,
An introduction part having the introduction pipe connected to a side surface;
A trunk portion provided on the downstream side of the introduction portion, and having a flow passage area in a plane perpendicular to the axial direction of the temperature reducing tower, which is larger than the introduction portion;
An enlarged portion that is provided between the introduction portion and the trunk portion and expands so that the flow area increases as it goes from the introduction portion to the trunk portion,
A nozzle that is provided in the body and sprays droplets on the gas;
With
The angle formed between the inner surface of the enlarged portion and the axis of the temperature-decreasing tower is greater on the side surface facing the side surface on which the introduction pipe is provided than on the side surface on which the introduction tube is provided in the introduction portion. A cooling tower characterized by its large size. The inner surface of the enlarged portion includes a first inclined portion provided on the introduction portion side, and a second inclined portion provided to be continuous with the downstream side of the first inclined portion,
2. The temperature reducing tower according to claim 1, wherein an angle formed between the first inclined portion and the axis of the temperature reducing tower is smaller than an angle formed between the second inclined portion and the axis of the temperature reducing tower. .

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