JPS5854586Y2 - liquid heating device - Google Patents

Description

[Detailed description of the invention] This invention is used to heat liquids to be heated, such as processing liquids before painting, and the high-temperature combustion gas ejected by a burner is transferred to a gas tank immersed in a liquid tank. A so-called immersion liquid is configured to heat the liquid to be heated in the liquid tank by introducing the heat exchanger tube into the heat exchanger tube through an inlet tube section at one end and discharging it from the other end discharge tube section. This invention relates to a tubular liquid heating device.

In a conventional liquid heating device of this kind, as shown in FIG. It consisted of a simply bent or straight, in other words, an open-loop type immersion pipe, which reached the discharge pipe component at the other end through part e.

Therefore, in order to improve the heating efficiency, it was necessary to increase the heat transfer area by increasing the number of bends to increase the tube length or by increasing the tube diameter.

However, when such a method is adopted, the heat exchanger tube becomes larger and occupies a larger volume in tank a, which compresses the effective working space in tank a and causes problems in workability. However, if tank a itself is unduly enlarged, the overall size of the equipment will not only be reduced, but the amount of liquid to be processed will also increase, which is especially difficult for equipment that requires uniformity in temperature distribution. In this case, a new problem arises in that a liquid stirring device or the like must be additionally installed.

Furthermore, when increasing the length of the pipe by increasing the number of bends,
As the flow resistance of the pipe increases, the flow velocity in the pipe decreases, and when the pipe diameter is increased,
As is clear from Bernoulli's theorem, since the flow velocity in the pipe also decreases, there is a drawback that the convective heat transfer coefficient decreases and the heating efficiency deteriorates.

In order to eliminate these drawbacks, burner C
Therefore, it is necessary to use a fairly large pipe with a high jetting pressure to maintain the flow velocity in the pipe and thus the convective heat transfer coefficient at a predetermined value.

The present invention was developed in view of the existing circumstances, and its purpose is to dramatically increase the flow velocity in the heat transfer tube and the convective heat transfer coefficient while using a small burner with relatively low ejection pressure. Therefore, it is an object of the present invention to provide a liquid heating device that can exhibit sufficient heating performance while making the heat exchanger tube as small as possible and occupying a small proportion in the tank.

In order to achieve the above object, the liquid heating device according to the present invention has the configuration described at the beginning, and includes forming an annular closed loop tube section between the introduction tube section and the discharge tube section of the heat transfer tube. , the inlet tube portion is disposed substantially tangentially to the annular closed loop tube portion, and the discharge tube portion is disposed in a direction different from the flow direction tangent to the annular closed loop tube portion. By providing this, the high-temperature combustion gas is configured to be circulated within the annular closed loop pipe section by utilizing the ejection energy of the high-temperature combustion gas ejected and introduced by the burner.

According to the above characteristic configuration, various excellent effects as described below are exhibited.

That is, (a) high-temperature combustion gas ejected from the burner is continuously introduced into the annular closed loop tube section, but since the gas introduction direction is tangential to the flow path of the closed loop tube section,
In addition, since the gas discharge flow path from the closed loop pipe section is bent in a direction different from the flow direction within the closed loop pipe section, a certain degree of gas discharge resistance can be generated in that section. A part of the high-temperature combustion gas that has passed through the annular closed-loop pipe section and returned is sucked and mixed with the newly introduced high-temperature combustion gas by the ejector effect based on the gas ejection energy of the burner. , the gas flow rate in the closed-loop pipe section is increased, necessarily increasing its flow rate, and thus:
The convection heat transfer coefficient is increased, and (a) the high-temperature combustion gas introduced into the heat exchanger tube is not directly discharged after performing one heating action as in the conventional method. By having a structure in which a part of the gas is circulated in a closed loop pipe, the high-temperature combustion gas is equivalent to passing through a pipe that is longer than the actual pipe length, and therefore, the retained heat is used as efficiently as possible for heating action. Therefore, both effects (a) and (b) above work together,
According to the present invention, a relatively small burner with low ejection pressure can be used as a burner for the high-temperature combustion gas generation phase, and a relatively small one with a small volume occupying a small volume in the liquid tank can be used as a heat transfer tube. Even when using the liquid heating device, we were able to obtain a compact liquid heating device that can exhibit extremely excellent heating performance and that can also secure a sufficient working space.

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

A high-speed burner 3 that spouts high-temperature combustion gas at high speed is attached to a portion corresponding to the outer wall of the tank 1, and the high-temperature combustion gas spouted by the burner 3 is sent to the bottom of the liquid tank 1 via supports 6, 6. The tubes to be heated in the liquid tank 1 are introduced into the heat exchanger tube 2 which is immersed and arranged through the introduction tube section 2A at one end of the heat exchanger tube 2, and discharged from the other end discharge tube section 2B of the heat exchanger tube 2. In a liquid heating device configured to heat a
The introduction pipe portion 2A and the discharge pipe portion 2B of the heat transfer tube 2 are arranged close to each other, and both 2A, 2
A substantially elliptical annular closed loop tube portion 2C is formed between the tube portions B, and the introduction tube portion 2A is connected to the closed loop tube portion 2.
C, and by arranging the discharge pipe portion 2B in a direction different from the flow direction tangent to the closed loop pipe portion 2C, the ejection by the burner 3 is The high temperature combustion gas is configured to be circulated within the closed loop pipe section 2C at an increased average flow velocity by utilizing the ejection energy of the introduced high temperature combustion gas.

The bottom wall 1a and the peripheral side wall 1b of the tank 1 are made of a metal plate having good thermal conductivity, such as an aluminum plate, and a heat insulating wall 4 is provided on the outside of the tank 1 at an appropriate interval. Accordingly, this heat insulating wall 4 and each metal plate wall 1a, l of tank 1
A gas discharge channel 5 along the entire outer peripheral surface of the tank 1 is formed between the tank 1 and the gas discharge channel 5, and the gas discharge channel 5 is formed in a portion of the discharge channel 5 located below the bottom wall 1a of the liquid tank 1. The downward discharge pipe portion 2B of the heat pipe 2 is connected to the discharge port 2a.
The structure is such that the exhaust gas sequentially discharged from the tank 1 is upwardly discharged along the bottom and side surfaces of the tank 1.

According to this configuration, the outer walls 1a and 1b of the tank 1 can also be used as a heat transfer area, and the remaining heat of the exhaust gas can be used for the heating effect. It also has a heat retention effect that can be suppressed by the wall,
The desired heating efficiency improvement effect can be further enhanced.

In addition, numeral 7 in the figure is a discharge hole through which exhaust gas is discharged from the discharge flow path 5 to the outside.

[Brief explanation of drawings]

The drawings illustrate embodiments of the liquid heating device according to the present invention,
FIG. 1 is a partially longitudinal side view, FIG. 2 is a plan view, and FIG. 3 is an explanatory diagram of a conventional device. 1...Liquid tank, 2...Heat transfer tube, 2A...
...Introduction pipe part, 2A...Discharge pipe part, 2C...Annular closed loop pipe part, 4...
・Insulating wall, 5... Discharge channel.

Claims (1)

[Scope of claim for utility model registration] ■ The high temperature combustion gas ejected by the burner 3 is
The liquid in the liquid tank 1 is introduced into the heat exchanger tube 2 immersed in the liquid tank 1 through the introduction pipe section 2A at one end of the heat exchanger tube 2, and discharged from the other end through the discharge pipe section 2B. A liquid heating device configured to heat a heating liquid, in which an annular closed loop pipe portion 2C is formed between the introduction pipe portion 2A and the discharge pipe portion 2B of the heat transfer tube 2, and the introduction pipe The portion 2A is disposed approximately in a tangential direction to the annular closed loop pipe portion 2C, and the discharge pipe portion 2B is disposed in a direction different from the flow direction tangent to the annular closed loop pipe portion 2C. A liquid heating device characterized in that the high temperature combustion gas is circulated within the annular closed loop pipe section 2C by utilizing the ejection energy of the high temperature combustion gas ejected and introduced by the burner 3. ■ The introduction pipe portion 2A and the discharge pipe portion 2 of the heat transfer tube 2
A liquid heating device according to claim 2 of the utility model registration claim, characterized in that B and B are arranged close to each other. (2) A utility model characterized in that the discharge pipe portion 2B of the heat transfer tube 2 is communicated with a discharge passage 5 formed between the liquid tank 1 and a heat insulating wall 4 provided on the outside thereof. A liquid heating device according to registered claim No. (2). (2) The discharge flow path 5 is formed along the entire outer peripheral surface of the liquid tank 1, and the discharge pipe portion 2 of the heat transfer tube 2 is formed along the entire outer peripheral surface of the liquid tank 1.
The liquid heating device according to claim 2, wherein B is communicated with a portion of the discharge flow path 5 located below the liquid tank 1.