JPH08247684A - Heat exchanger - Google Patents

Abstract

PURPOSE: To obtain a heat exchanger which improves the efficiency of heat exchange and enables reduction of the size. CONSTITUTION: In regard to a heat exchanger wherein a large number of heat transfer tubes 2 are arranged inside a tubular casing 1 of which the upper end is made an inflow port 11 of heat transfer gas and the lower end an outflow port 12 thereof and in the direction parallel to the longitudinal direction of the tubular casing 1, an axial column 3 provided with a fin 31 projecting spirally in the direction from the inflow port 11 to the outflow port 12 is placed at a position corresponding to the axis of the tubular casing 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell-and-tube type heat exchanger suitable for heat recovery of high temperature exhaust gas generated from a heating furnace, an incinerator, etc., and more particularly to a U-shaped heat transfer tube type heat exchanger. Regarding the improvement of vessels.

[0002]

2. Description of the Related Art A conventional U-shaped heat transfer tube type heat exchanger will be described as an example. As shown in FIG. 4, one end of a cylindrical casing 1 serves as an inlet 11 through which heat transfer gas flows. , The other end is used as the outlet 12 through which the heat transfer gas flows out, and a large number of U-shaped heat transfer gases are provided on the side wall at one end thereof.
A distributor 21 that distributes to the letter-shaped heat transfer tube 2 and a collector 22 that collects and discharges the heat-transferred gas after receiving the heat are arranged in parallel. Both ends of the U-shaped heat transfer tube 2 are fixed to the side wall of the tubular casing 1 and are connected to the distributor 21 and the collector 22, respectively. The two folded straight line portions 2a and 2b of the heat transfer tube 2 are arranged parallel to the longitudinal direction of the tubular casing 1, that is, the flow direction of the heat transfer gas. In this way, a large number of heat transfer tubes 2 are radially arranged in the tubular casing 1.

In the case of the above heat exchanger, the two folded straight line portions 2a and 2b of the heat transfer tube 2 are arranged parallel to the flow direction of the heat transfer gas in the cylindrical casing 1. Although it has excellent durability against repeated thermal expansion and contraction that occurs during operation, it was necessary to lengthen the heat transfer tube 2 and the tubular casing 1 in order to improve the heat exchange efficiency. In that case, there is a problem that the manufacturing cost increases and the durability of the heat transfer tube 2 deteriorates. In addition, in response to recent needs for miniaturization of the heat exchanger,
For the same reason, there was a problem that it was difficult to deal with.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a heat exchanger capable of improving the heat exchange efficiency and further downsizing. .

[0005]

SUMMARY OF THE INVENTION The above problem is caused by arranging a large number of heat transfer tubes in a cylindrical casing that allows heat transfer gas to flow from one side to the other in a direction parallel to the longitudinal direction of the cylindrical casing. The heat exchanger described above can be solved by a heat exchanger characterized by including means for imparting a swirl flow to the heat transfer gas that flows in.

[0006]

In the present invention, the means for imparting a swirl flow to the inflowing heat transfer gas is provided. Therefore, the heat transfer gas becomes a swirl flow inside the tubular casing of the heat exchanger, and the heat transfer gas flows from the inlet to the outlet. Since the fluid flows in the direction, the contact time with a large number of heat transfer tubes arranged in a direction parallel to the longitudinal direction of the tubular casing is significantly increased, and heat exchange efficiency can be improved. Further, even when the heat transfer gas contains a large amount of dust, the dust is less likely to be deposited on the heat transfer tube due to the swirling flow, so that the heat exchange efficiency is less likely to decrease.

[0007]

EXAMPLES The present invention will be described in detail with reference to the examples shown in FIGS. (Embodiment 1) First, the U-shaped heat transfer tube type heat exchanger shown in FIG. 1 will be described as an example. The cylindrical casing 1 has one end serving as an inflow port 11 through which heat transfer gas flows, and the other end transferred. The outlet 12 through which the hot gas flows out is provided with a distributor 21 for distributing the heat-transferred gas to a number of U-shaped heat transfer tubes 2 and a heat-transferred gas after receiving heat on the side wall at one end thereof. Collecting device 2
2 are installed side by side. Both ends of the U-shaped heat transfer tube 2 are fixed to the side wall of the tubular casing 1 and the distributor 2
1 and the aggregator 22 respectively. The two folded straight line portions 2 a and 2 b of the heat transfer tube 2 are arranged parallel to the longitudinal direction of the tubular casing 1. In this way, a large number of heat transfer tubes 2 are radially arranged in the tubular casing 1 between the axis of the tubular casing 1 and the inner wall. In this embodiment, the tubular casing 1
A jacket 23 is provided around the distributor 1, one of which is connected to the distributor 21, and the heat transfer gas introduced from the other is preheated through the tubular casing 1 while the distributor 2
However, the heat transfer target gas may be directly supplied to the distributor 21.

Although the structure described above is the same as the conventional structure, in this embodiment, as a means for imparting a swirl flow to the heat transfer gas flowing in, a position corresponding to the axis of the cylindrical casing 1 as shown in FIG. The shaft column 3 having the fins 31 spirally protruding from the direction of the inflow port 11 to the direction of the outflow port 12 is disposed (the lower part of the shaft column 3 is omitted in FIG. 1). In this case, it is preferable that the fin 32 is provided on the inner wall of the cylindrical casing 1 so as to project in a spiral shape in the same spiral direction as the fin 31 of the shaft column 3 (in FIG. 1, the upper portion of the fin 32 is described. Omitted).

In this embodiment, since the means for imparting the swirling flow as described above is provided, the heat transfer gas flowing in from the inlet 11 has the spiral fin 31 protruding from the shaft column 3.
By colliding with, the flow direction is changed to form a spiral swirling flow, which flows toward the outlet 12. Further, since this swirl flow flows with a flow component in the direction along the inner wall, the fins 3 are formed on the inner wall of the tubular casing 1.
When 2 is projected in a spiral shape, the flow is urged by the fins 32 and a preferable swirling flow is obtained.

(Second Embodiment) The present invention can also be embodied as a second embodiment shown in FIG. The short tubular casing 4 is arranged continuously above the inflow port 11 and forms a part of the inflow passage of the heat transfer gas. Inside the short tubular casing 4, two semi-elliptical deflection plates are provided. 41 and 42 are provided in a tilted manner with respect to the flow of the heat transfer gas, assuming that they are twisted in opposite directions with the minor axis as an axis. Therefore, in this embodiment, the heat transfer gas that has flowed into the short tubular casing 4 has two semi-elliptical deflection plates 41 twisted in opposite directions about the short diameter axis.
By colliding with 42, the flow direction is changed and a swirling flow is made to flow into the cylindrical casing 1, so that the same action as described above occurs. In this embodiment, the deflecting plates 41 and 42 are arranged in the short tubular casing 4, but the deflecting plates 41 and 42 themselves may be arranged directly below the inflow port 11.

(Third Embodiment) Further, the present invention can be embodied as a third embodiment shown in FIG. The short tubular casing 5 provided with the lid 51 is continuously arranged above the inflow port 11 and forms a part of the inflow passage of the heat transfer gas. A heat transfer gas introducing pipe 52 is eccentrically attached to the axial center of the short tubular casing 5 and opens inside the short tubular casing 5. Therefore, in this embodiment, the heat transfer gas flowing from the heat transfer gas introduction pipe 52 into the short cylindrical casing 4 is
The direction of the flow is changed along the inner wall of the above, and it becomes a swirling flow and flows into the cylindrical casing 1, so that the same operation as in the above-mentioned embodiment occurs. Although the heat transfer gas introduction pipe 52 is attached to the short tubular casing 5 in this embodiment, it may be changed to be attached to the uppermost side wall of the tubular casing 1.

[0012]

As described above, the heat exchanger of the present invention is provided with the means for imparting the swirl flow to the inflowing heat transfer gas, so that the heat transfer gas becomes a swirl flow from the inlet direction. Since it flows in the outlet direction, the contact time with a large number of heat transfer tubes arranged inside the tubular casing is significantly increased, and heat exchange efficiency can be improved, and the heat exchanger can be downsized. There is an excellent effect. Further, even when the heat transfer gas contains a large amount of dust, the dust is less likely to be deposited on the heat transfer tube due to the swirling flow, and the heat exchange efficiency is less likely to decrease, so that the operation can be performed for a long period of time. Therefore, the present invention, as a heat exchanger that solves the conventional problems,
Its industrial value is extremely high.

[Brief description of drawings]

FIG. 1 is a partially cutaway conceptual view showing a first embodiment.

FIG. 2 is a partially cutaway perspective conceptual view showing a second embodiment.

FIG. 3 is a partially cutaway perspective conceptual view showing a third embodiment.

FIG. 4 is a partially cutaway conceptual view showing a conventional heat exchanger.

[Explanation of symbols]

1 tubular casing, 11 inflow port, 12 outflow port, 2
Heat transfer tubes, 31, 32 fins, 41, 42 deflection plates, 5
2 Heat transfer gas introduction pipe.

Claims (1)

[Claims] 1. A heat exchanger in which a large number of heat transfer tubes are arranged in a direction parallel to the longitudinal direction of a cylindrical casing in which a heat transfer gas can flow from one side to the other. A heat exchanger having means for imparting a swirling flow to the heat transfer gas.