JPH0726791B2 - Direct steam heating type heat exchanger - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam direct heating type heat exchanger installed in a tank containing a large amount of raw water,
In particular, the present invention relates to a small-sized steam direct heating heat exchanger which directly mixes high-temperature and high-pressure steam with cold water as raw water without generating noise and heats a large amount of industrial water to high temperature in a short time.

[0002]

2. Description of the Related Art Conventionally, as a method for obtaining high-temperature industrial water, a heater (heat exchanger) using the principle of ejector and diffuser is installed by being connected to a tank or by being connected on a fluid transfer pipe. It is installed, and high-temperature and high-pressure steam is pumped and mixed with cold water flowing in the pipe to obtain high-temperature industrial water.

The operation principle of the conventional method will be described in more detail. The raw water, which is cold water, is introduced in one direction into a diffuser having a venturi-shaped nozzle in which the flow passage is gradually narrowed and then widened. An ejector having a nozzle passage having the same shape as the diffuser is installed behind the diffuser in the raw water flow direction. Then, high-temperature and high-pressure steam is pressure-fed toward the front of the raw water flow direction of the diffuser through the ejector, so that cold water is mixed with the high-temperature steam while passing through the nozzle of the diffuser, and cold water and steam are mixed in this mixing process. The heat exchange action is carried out to obtain high-temperature industrial water.

[0004]

However, in applying such a conventional method, when the industrial water required is relatively small, the object can be achieved without any problem, but a large amount of industrial water is used. There were various problems as follows when trying to obtain water. That is, a relatively large amount of steam should be pumped in order to raise the temperature of a large amount of cold water, and in order to satisfy such conditions, it is necessary to install an ejector and a diffuser with a large inner diameter, There was a problem that it required a high equipment cost. Moreover, even when using the device, a rapid increase in entropy occurs in the process of mixing a large amount of steam with low density and high pressure with a large amount of cold water, and this rapid increase in entropy causes an unbalanced heat exchange effect. For steam hammering (stea
m hammering) and water hammering (water ha
mmering) phenomenon occurs at the same time, resulting in extremely high noise and vibration. Further, as such noise and vibration repeatedly occur, cracks and damages to structures such as tanks occur. There was a point.

Therefore, the present invention was developed in order to solve the above problem, and adopts a circulating induction system of hot water to install a plurality of small ejectors and diffusers on the same axis. In addition to reducing the size of the entire device, it is possible to heat a large amount of raw water and to generate a thin film phenomenon by using vapor pressure of unmixed vapor and fluid to muffle the sound. An object is to provide a direct heating type heat exchanger.

[0006]

In order to achieve the above object, the steam direct heating type heat exchanger of the present invention is provided with an inner cylinder 2 in an outer cylinder 1 installed in the raw water at appropriate intervals, A heat exchange chamber 20 is formed by closing an end wall 15 between one end of the inner cylinder 2 and one end of the outer cylinder 1. In the heat exchange chamber 20, a split ejector 3 having a cylindrical steam inlet 21 and a steam outlet 22 each having a pair of venturi-shaped nozzles, a raw water inlet 24, and a mixed fluid outlet 25.
A plurality of pairs of divided diffusers 4 having the same shape are provided by inserting the steam jet ports 22 of the divided ejector 3 into the raw water inlet 24 of the divided diffuser 4 through the gap 23 on the same axis. Further, inflow holes 7 (8, 9) through which raw water flows are provided in a gap 23 between the split ejector 3 and the split diffuser 4 in the heat exchange chamber 20. Further, a high-pressure steam supply source is connected to the steam inlet 21 of the split ejector 3, and is connected to the other end of the inner cylinder 2 in front of the split diffuser 4 in the jet direction of the mixed fluid and the inner wall surface of the outer cylinder 1. The taper pipe 10 is provided so as to incline at an acute angle toward.

In addition, a plurality of pairs of split ejectors 3 and split diffusers 4 may be annularly arranged in the heat exchange chamber 20 around the inner cylinder 2.

In the inner cylinder 2, the raw water is supplied to the primary inflow hole 7 for injecting the raw water into the gap 23 between the divided ejector 3 and the divided diffuser 4, and the primary mixed fluid ejected from the mixed fluid ejection port 25 of the divided diffuser 4. It is effective to provide a secondary inflow hole 8 for inflowing to form a secondary mixed fluid and a tertiary inflow hole 9 for inflowing raw water into the secondary mixed fluid in the outer cylinder 1.

[0009]

The high-temperature high-pressure steam supplied from the high-temperature steam supply source into the heat exchange chamber 20 is used as the steam inlet 2 of each split ejector 3.
1 and is injected from the steam outlet 22 into the split diffuser 4, the raw water in the inner cylinder 2 is introduced into the inflow holes 7 (8, 9).
From the gap 2 between the split ejector 3 and the split diffuser 4
The primary mixed fluid that is sucked into the split diffuser 4 via the flow path 3 and is primarily mixed with the vapor and heat-exchanged is the tapered pipe 10.
It jets toward the wall surface of. Then, it collides strongly with the taper tube 10, a thin film phenomenon occurs, and the sound is silenced and no vibration occurs.
It is converged in the direction of the other end of the tapered tube 10. The raw water in the tank 16 is circulated again in the inner cylinder 2 and the heat exchange chamber 20, and the water temperature rises.

According to another aspect of the present invention, the raw water in the inner cylinder 2 is sucked from the secondary inflow hole 8 and secondarily mixed with the primary mixed fluid to form a secondary mixed fluid. According to another aspect of the present invention, the raw water outside the outer cylinder 1 flows in through the tertiary inflow hole 9 and is tertiary mixed with the secondary mixed fluid to flow outward from the tapered pipe 10 and the other end of the outer cylinder 1. The raw water that has flowed out and circulates in the inner cylinder 2 and the heat exchange chamber 20 again in the tank 16, and the water temperature rises.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention thus constructed will be described in more detail with reference to the accompanying drawings.

The steam direct heating type heat exchanger of the present invention is shown in FIG.
As shown in FIG. 2, a cylindrical inner cylinder 2 shorter than the outer cylinder 1 at an appropriate interval is provided substantially at the center of the cylindrical outer cylinder 1 installed in a tank 16 containing raw water such as industrial water.
To provide. Further, a space between one end of the inner cylinder 2 and one end of the outer cylinder 1 is closed by an end wall 15, and a funnel shape is formed on the other end of the inner cylinder 2 between the other end of the inner cylinder 2 and the other end of the outer cylinder 1. The taper pipe 10 that forms the taper pipe 1 is connected so as to incline toward the other end of the outer cylinder 1.
An outlet 18 for a mixed fluid of steam and raw water is provided between the end portion of 0 and the end portion of the outer cylinder 1.

Further, a flow path wall 13 having a cylindrical shape is provided on the outer circumference of the inner cylinder 2 in the same axial direction in a space formed by the outer cylinder 1, the inner cylinder 2, the tapered tube 10 and the end wall 15.
One end of the flow path wall 13 is appropriately spaced from the wall surface of the end wall 15, and a partition wall 14 closes the other end of the flow path wall 13 and the inner wall surface of the outer cylinder 1. In the space between the flow path wall 13 and the outer cylinder 1, a flow path is formed in which the steam pressure-fed from a steam supply pipe 19 described later flows in one direction toward the end wall 15. The heat exchange chamber 20 is formed in the space between the inner peripheral surface and the outer peripheral surface of the inner cylinder 2.

The outer cylinder 1, the inner cylinder 2, and the flow path wall 13
Is not limited to a cylindrical shape, and may be a cylindrical body having another shape.

Further, a steam supply pipe 19 is provided on the outer wall surface of the outer cylinder 1 so as to communicate with a flow path formed by the inner wall surface of the outer cylinder 1 and the outer peripheral surface of the flow path wall 13, and the steam supply pipe 19 is provided. Is fixed to the inner wall surface of the tank 16 via a flange 5 provided on the outer circumference of the steam supply port 6 at one end of the tank 1.
6 is connected to a steam pipe 17 communicating with a high pressure steam supply source (not shown) provided on the outer wall surface. Therefore, the high-pressure steam pumped from the steam pipe 17 passes through the steam supply port 6 and the inside of the steam supply pipe 19 to flow into the outer cylinder 1.

Further, as shown in FIG. 1, in the heat exchange chamber 20, one split ejector 3 and one split diffuser 4 having a venturi-shaped nozzle and having the same shape are formed as a pair. Provided on the axis through a gap 23,
A plurality of pairs of the split ejector 3 and the split diffuser 4 forming the pair, and the heat exchange chamber 20 between the flow path wall 13 and the inner cylinder 2
Place inside. That is, as shown in FIG. 2, the split ejector 3 and the split diffuser 4 are annularly arranged around the inner cylinder 2 in the same axial direction as the inner cylinder 2. Therefore, the number of each divided ejector 3 and each divided diffuser 4 is the same.

The structure of the split ejector 3 and the split diffuser 4 forming the pair will be described in more detail with reference to FIG.
As shown in, the split ejector 3 and the split diffuser 4
Each have a cylindrical shape having a venturi-shaped nozzle, the split ejector 3 includes a steam inlet 21 and a steam outlet 22, and the split diffuser 4 includes a raw water inlet 24.
And a mixed fluid ejection port 25. The split diffuser 4 is installed in front of the split ejector 3 in the direction of steam injection, and the steam jet port 22 of the split ejector 3 is inserted into the raw water inlet 24 of the split diffuser 4 through the gap 23 for sucking the raw water in the tank 16 through the same axis. It is inserted on the line.

Each divided ejector 3 is fixed between the inner cylinder 2 and the flow path wall 13 by an ejector fixing base 11, and each divided diffuser 4 is fixed by a diffuser fixing base 12 in the inner cylinder 2.
And the flow path wall 13 are fixed. In order for the high-pressure steam sent from the high-pressure steam supply source to effectively flow into the split ejector 3, the ejector fixing base 11 or another partition wall is provided between the inner cylinder 2 between the ejectors 3 and the flow path wall 13. It is preferable to close the inner cylinder 2 between the divided diffusers 4.
It is preferable that the diffuser fixing base 12 or another partition wall similarly closes between the channel wall 13 and the channel wall 13. Therefore, the steam flowing through the flow path between the outer cylinder 1 and the flow path wall 13 flows into the steam inlet 21 of the split ejector 3, and is injected into the split diffuser 4 from the steam outlet 22 via the venturi-shaped nozzle.

A plurality of primary inflow holes 7 are provided in the inner cylinder 2 so that the raw water in the inner cylinder 2 flows into the gap 23 between each divided ejector 3 and the divided diffuser 4. It is effective to provide the primary inflow holes 7 in the inner cylinder 2 at a position close to the gap 23. In this case, the number of the primary inflow holes 7 is the same as that of the split ejector 3 and the split diffuser 4. , But not limited to this number.

Further, a plurality of secondary inflow holes 8 are provided in the inner cylinder 2 at a position near the mixed fluid ejection port 25 of each divided diffuser 4. The primary mixed fluid formed by the steam injected from each divided ejector 3 and the raw water flowing from the primary inflow hole 7 being mixed and heat-exchanged in the nozzle of each divided diffuser 4 is ejected from the mixed fluid ejection port 25. Since the plurality of secondary inflow holes 8 are inflow ports for injecting the raw water in the inner cylinder 2 into the primary mixed fluid to replenish it for secondary mixing, most of the secondary fluid inflow ports 25 of each split diffuser 4 are connected to the primary mixed fluid. It is effective and preferable to provide the inner cylinder 2 at a close position, and the same number as the divided diffuser 4, but the number and the position are not limited to the illustrated embodiment.

The outer cylinder 1 located on the side closer to the outlet 18 than the partition wall 14 is for replenishing the raw water outside the outer cylinder 1 to the secondary mixed fluid, which has been secondarily mixed, for tertiary mixing. A plurality of tertiary inflow holes 9 are provided on the entire circumference at appropriate intervals.
The position and number of the tertiary inflow holes 9 are similar to those of the primary inflow holes 7 and the secondary inflow holes 8, and are preferably close to the jet position from the split diffuser 4 and the same as the split diffuser 4, but are not limited thereto. Not something.

A wall surface of the above-mentioned taper pipe 10 which is inclined at an acute angle is provided in front of the jet direction of the primary mixed fluid jetted from the mixed fluid jet port 25 of the divided diffuser 4.

The operation of the above embodiment will be described below.

The outer cylinder 1 of the apparatus of the present invention is installed in the inner wall of the tank 16 via the flange 5 of the steam supply pipe 19 in a state of being immersed in the raw water in the tank 16, and is not shown outside the tank 16. High temperature steam from high temperature steam supply steam pipe 1
When high pressure is supplied to the steam supply port 6 of the steam supply pipe 19 via 7, the high temperature steam passes through the inside of the steam supply pipe 19, passes through the entire flow path between the outer cylinder 1 and the flow path wall 13, and passes through the flow path wall 13 Through the space between one end of the split ejector 3 and the end wall 15 into the steam inlet 21 of each split ejector 3, is squeezed by a venturi-shaped nozzle, and is jetted at a higher pressure to be discharged from the steam jet 22 to the nozzle of the split diffuser 4. Is jetted toward. The raw water of the tank 16 in the inner cylinder 2 is sucked into the split diffuser 4 from the primary inflow hole 7 through the gap 23 between the split ejector 3 and the split diffuser 4 by the jet flow of the steam, and the sucked raw water is The primary mixed fluid is formed by primary mixing with the high-temperature and high-pressure steam and heat exchange by the strong pressure of the fluid of the steam and the raw water at the nozzle of each split diffuser 4. Next, this primary mixed fluid is mixed fluid ejection port 2 of each divided diffuser 4.
Spray from 5 toward the wall surface of the taper pipe 10. Due to the jet flow of the primary mixed fluid, the raw water in the inner cylinder 2 becomes the secondary inflow hole 8
After being sucked and replenished and secondary mixed with the primary mixed fluid, it collides strongly with the tapered tube 10 and is converged in the direction of the outlet 18. Then, the raw water outside the outer cylinder 1 flows in through the tertiary inflow hole 9, is tertiary mixed with the secondary mixed fluid, and flows out of the outer cylinder 1 through the outlet 18.

As the high temperature steam is supplied as described above, the cold water which is the raw water in the tank 16 circulates in the inner cylinder 2 and the water temperature in the tank 16 rises.

The unmixed vapor and the fluid of the raw water cause a thin film phenomenon when they strongly collide with the wall surface of the taper tube 10 due to the pressure of the vapor.

In the case of a heater using a conventional general ejector and diffuser, and in the device of the present invention, the taper pipe 1 is used.
As a result of an experiment in which 0 is removed, when the mixing temperature of the fluid and vapor flowing out from the diffuser is 60 ° C or less, no hammering phenomenon and vibration occur, but when the mixing temperature is 60 ° C or more, The hammering phenomenon and vibration occurred violently. On the other hand, in the apparatus of the present invention provided with the tapered tube 10, the hammering phenomenon and the vibration did not occur at all even when the mixing temperature was 60 ° C. or higher. Therefore, the taper tube 10 of the device of the present invention has an effect of not causing the hammering phenomenon and vibration even when the mixing temperature exceeds 60 ° C.,
Since the noise can be reduced to 10 dB or less within a distance of 1 m from the installation location of the device of the present invention, the structure of the device itself is prevented from being destroyed.

That is, when the unmixed high temperature steam and the fluid of the raw water collide with the taper tube 10 due to the force of the steam, surface tension acts on the wall surface of the taper tube 10 to form a high-pressure thin film hot water film. flow) is formed, and unmixed wet saturated vapor, which is a relatively low-density molecular layer that collides with this hot water film, is adsorbed and completely mixed in a blink with secondary and tertiary mixing, and the outside of the outer cylinder 1 Is leaked to.

The thickness of the hot water film can be adjusted by the pressure of the steam, and the noise can also be controlled by adjusting the thickness of the hot water film. Basically, the high temperature steam source can be operated at critical pressure of saturated steam or superheated steam of 220 kg / cm ² ABS or less and critical temperature of 372 ° C or less, and entropy increase (0.024 Kcal / Kg ° K 1 Kcal / Kg) operation Is possible.

In the above-described embodiment, the flow passage wall 13 is provided in the space between the outer cylinder 1 and the inner cylinder 2, but the flow passage wall 13 is not formed and the outer cylinder 1 and the inner cylinder 2 are not formed. The space between the inner cylinder 2 and the heat exchange chamber 20 is defined by a plurality of pairs of split ejectors 3 and diffusers 4 which are paired with each other in the inner cylinder 2 and which are annularly arranged around the inner cylinder 2. , The ejector 3 that divides the steam supply pipe 19 communicating with the high-pressure steam supply source into the outer cylinder 1 or the end wall 15.
Can be provided so as to communicate with the steam inlet 21 of At this time, the primary inflow hole 7 and the secondary inflow hole 8 do not necessarily have to be formed in the inner cylinder 2 as in the above-described embodiment, but may be formed in the outer cylinder 1 and / or the inner cylinder 2. The operation at this time is similar to that of the above-described embodiment.

[0031]

Since the present invention is constructed as described above, it has the following effects.

(1) In the heat exchange chamber between the outer cylinder and the inner cylinder, a pair of cylindrical divided ejectors and divided diffusers are provided, and a vapor ejecting port of the divided ejector is provided in the raw water inlet of the divided diffuser. Since a plurality of pairs are provided by inserting them on the same axis line through, and an inlet hole for introducing raw water is provided in the gap between the split ejector and the split diffuser in the heat exchange chamber, the outer cylinder itself can be made compact and We were able to provide a steam direct heating type heat exchanger that has excellent performance and can be widely produced from a small amount of hot water production to a large volume of industrial high temperature water.

(2) A taper pipe, which is connected to the other end of the inner cylinder and is inclined at an acute angle toward the inner wall surface of the outer cylinder, is provided in front of the split diffuser in the jet direction of the mixed fluid. It was possible to provide a steam direct heating type heat exchanger capable of preventing the structure from being destroyed because it can be silenced to 10 dB or less within a distance of 1 m from the installation location of the device.

(3) Since a plurality of pairs of split ejectors and split diffusers are annularly arranged around the inner cylinder in the heat exchange chamber, high-pressure steam can efficiently flow into the steam inlet of each split ejector. It was possible to provide a small-sized and high-performance steam direct heating type heat exchanger.

(4) In the inner cylinder, primary water is introduced into the gap between the divided ejector and the divided diffuser, and raw water is introduced into the primary mixed fluid ejected from the mixed fluid ejection port of the divided diffuser to perform secondary mixing. Since a secondary inflow hole for forming a fluid and a tertiary inflow hole for inflowing raw water into the secondary mixed fluid are further provided in the outer cylinder, the newly introduced raw water in each primary, secondary, and tertiary mixing has a high temperature. It was possible to provide an efficient steam direct heating type heat exchanger because it efficiently exchanges heat with the above steam.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a working state according to an embodiment of the apparatus of the present invention.

FIG. 2 is a side view of FIG.

[Explanation of symbols]

 1 Outer Cylinder 2 Inner Cylinder 3 Split Ejector 4 Split Diffuser 6 Steam Supply Port 7 Primary Inlet Hole 8 Secondary Inlet Hole 9 Tertiary Inlet Hole 10 Tapered Tube 15 End Wall 19 Steam Supply Pipe 20 Heat Exchange Chamber 21 Steam Inlet 22 Steam Injector Outlet 23 Gap 24 Raw water inlet 25 Mixed fluid jet

Claims (3)

[Claims] 1. A heat exchange chamber is formed by providing an inner cylinder in an outer cylinder to be installed in raw water with an appropriate interval and closing an end wall between one end of the inner cylinder and one end of the outer cylinder. , In the heat exchange chamber,
A split ejector having a steam inlet and a steam outlet, and a split diffuser having a raw water inlet and a mixed fluid jet, each having a pair of venturi-shaped nozzles, and a steam outlet of the split ejector. A plurality of pairs are provided in the raw water inlet of the diffuser by inserting them on the same axis line through a gap, and further, an inlet hole for introducing raw water is provided in the gap between the split ejector and the split diffuser in the heat exchange chamber, and the split ejector A high-pressure steam supply source is connected to the steam inlet, and a taper pipe, which is connected to the other end of the inner cylinder and is inclined at an acute angle toward the inner wall surface of the outer cylinder, is provided in front of the split diffuser in the jet direction of the mixed fluid. A steam direct heating type heat exchanger characterized by being provided. 2. The steam direct heating heat exchanger according to claim 1, wherein a plurality of pairs of split ejectors and split diffusers are annularly arranged around the inner cylinder in the heat exchange chamber. 3. A primary mixed hole into which the raw water flows into the gap between the split ejector and the split diffuser, and a raw mixed water which flows into the primary mixed fluid ejected from the mixed fluid ejection port of the divided diffuser to the secondary mixed fluid. A secondary inlet hole forming
The steam direct heating type heat exchanger according to claim 1 or 2, further comprising a tertiary inflow hole for allowing raw water to flow into the secondary mixed fluid in the outer cylinder.