JPS58231A - Vapor mixer - Google Patents

Abstract

PURPOSE:To mix efficiently equal quantities of two steams of vapor, by arranging an outside cylinder and an inside cylinder having vapor valves in a pipe of the vapor to be mixed and inserting a pipe of the mixing vapor orthogonal to this pipe into the outside cylinder. CONSTITUTION:In a vapor mixer where a pipe 1 of the vapor to be mixed and a pipe 2 of the mixing vapor are orthogonal to each other, an outside cylinder 5 and an inside cylinder 6 which have both ends opened are arranged at an interval in the pipe 1 of the vapor to be mixed, and the pipe 2 of the mixing vapor is inserted into the outsdie cylinder 5, and vapor valves 4 are provided on the circumference of the inside cylinder 6. Then, though the mixing vapor collides orthogonally against the vapor to be mixed after flowing to the space between the cylinder 5 and the cylinder 6, a part of the mixing vapor is flowed into the cylinder 6 through the valves 4 of the cylinder 6. Thus, equal quantities of two steams of vapor are mixed efficiently and sufficiently.

Description

[Detailed Description of the Invention] For steam mixing in a compounding plant combining a steam turbine and one steam turbine, for steam mixing in a line where the combination of flow rates of mixed steam and mixed steam varies significantly, for closed type steam mixing This invention relates to a steam mixer for steam mixing in lines where it is difficult to use a steam mixer.

An example of a conventional steam mixer is shown in cross section in FIG. 1 and in vertical section in FIG. 2, respectively. 1 is a steam pipe to be mixed, and 3 is a mixer. The steam to be mixed flows into the mixer 3 from the left side of the mixer 3 through the steam to be mixed pipe 1, mixes with the mixed steam, and then flows out to the right.

The mixed steam flows into the mixer 3 from above through the mixed steam pipe 2, and is uniformly ejected into the mixed steam from the blowhole 4 of the mixer 3 to mix.

Efficiency (various considerations have been made to ensure uniform mixing).

As can be seen from the above example, in the conventional mixer, the steam to be mixed and the mixed steam are distinct, and the main purpose of the conventional mixer is to efficiently mix a small amount of mixed steam into a large amount of steam to be mixed.

Therefore, there is no distinction between mixed steam and mixed steam, and it is not suitable for the purpose of mixing equal amounts of steam. That is, since the flow rates of the steam to be mixed and the steam to be mixed are equal, the dimensions of the mixed steam pipe 2 are the same as those of the steam pipe 1 to be mixed. Therefore, the mixer cannot be formed with the structure as described above.

If the flow rate of the steam to be mixed is smaller than that of the mixed steam, the mixing will not be as good.One drawback is that the mixer 3 mentioned above has a closed structure, so if foreign matter gets inside. There is a risk that the gas will accumulate and block the nozzle hole 4. Special consideration is required especially to deal with free blow during construction.

In a combined plant that combines a plurality of gas turbine exhaust gas boilers and one steam turbine, due to its operating characteristics, it is necessary to mix steam having different steam temperatures before sending the mixture to the steam turbine. However, no suitable steam mixer has been found for this purpose. However, for this combined plant to be successful, a steam mixer that meets the above objectives is absolutely necessary.

In order to achieve this object, the steam mixer in the present invention has the following structure.

(1) There is no distinction between the steam to be mixed and the steam to be mixed (equal amounts of steam can be mixed; (2) the mixing efficiency does not decrease much even if the combination of flow rates of the steam to be mixed and the mixed steam varies; (3) ) The mixer has an open structure to prevent foreign matter from accumulating inside the mixer.

(4) Therefore, no special measures are required for free blowing during construction, and there is no need to install cleaning holes or inspection holes. (5) Because the structure ensures a sufficient steam passage area in the steam mixing section, the mixing section There is no need to increase the pipe size, (6)
The steam mixer has a double-tube structure to prevent the mixed steam from coming into direct contact with the tube wall, so thermal stress in the steam tubes in the mixing section can be reduced.

A cross section of a steam mixer according to an embodiment of the present invention is shown in FIG. 3, a vertical section is shown in FIG. 4, and an example of use of the steam mixer is shown in FIG.

The mixed steam flows into the mixer 3 from above through the mixed steam pipe 2. The steam flows into the intermediate gap B between the outer cylinder 5 and the inner cylinder 6, and a part of the steam flows into the inner cylinder 6 through the jet hole 4 provided in the inner cylinder 6. On the other hand, the steam to be mixed is mixed in the steam pipe 1.
and flows into the mixer 3 from the left. The steam that has flowed in directly flows into the intermediate gap B between the outer cylinder 5 and the inner cylinder 6 and into the interior of the inner cylinder 6.

The steam to be mixed that has flowed into the intermediate gap B between the outer cylinder 5 and the inner cylinder 6 collides with the mixed steam that has flowed in from above, mixes, and then flows out of the mixer 3. The steam to be mixed that has flowed into the interior of the inner cylinder 6 collides with the mixed steam ejected from the jet holes 4 provided around the entire circumference of the inner cylinder 6, mixes, and then flows out of the mixer 3. Figures 3 and 4.

Although not shown, the inner cylinder 6 and outer cylinder 5 are supported from the steam pipe 1 to be mixed, and are designed to sufficiently withstand vibrations and external forces caused by collisional mixing of steam (.

First, a state in which mixed steam is not mixed will be explained. Since the outer cylinder 5 and the inner cylinder 6 of the mixer 3 are arranged in the same direction as the flow direction of the steam to be mixed, the steam to be mixed flows through the gap A between the steam pipe 1 to be mixed and the outer cylinder 5, and the outer cylinder 5. Even after branching and flowing into the gap B with the inner cylinder 6 and the inside of the inner cylinder 6 with almost no hindrance, it flows out without any hindrance. That is, even when the mixer of the present invention is installed, the flow of steam is not obstructed, and foreign matter mixed in the steam does not accumulate inside the mixer. Next, a case where mixed steam flows in will be explained.

Since the mixed steam pipe 2 is inserted to the inside of the outer cylinder 5, the mixed steam does not come into direct contact with the inner wall of the mixed steam pipe 1, but flows into the gap B between the outer cylinder 5 and the inner cylinder 6.

This can prevent the temperature of the inner wall of the tube, which has been heated by the mixed steam passing through the gap, from changing suddenly by 1 degree due to the inflow of mixed steam. This is very important when mixing steam with different steam temperatures. The steam that has flowed into the gap B is perpendicular to the steam to be mixed, so that the steam collides and mixes violently, and a portion of the steam flows into the interior of the inner cylinder 6 through the blowhole 4 provided in the inner cylinder 6. Here, it is desirable that the cross-sectional area of the gap B, the internal cross-sectional area of the inner cylinder 6, and the total area of the blowholes 40 be distributed so that they are each approximately equal.

As a result, the steam to be mixed is also branched into approximately two parts between the gap B and the inner cylinder 6, and the mixed steam is also approximately divided into the gap B.
It is divided into two parts: and the inside of the inner cylinder 6.

The mixing ratio of the steam to be mixed and the mixed steam is approximately equal in the gap B and inside the inner cylinder 6, and uniform mixing is obtained. However, the number of blowholes 4 is small on the side where the mixed steam flows in, so that the steam is ejected almost uniformly over the entire circumference of the inner cylinder 6.

After the mixed steam collides and mixes at right angles with the steam to be mixed, it flows out without any hindrance. Therefore, there is no accumulation of foreign matter mixed into the steam.

Next, a case where no mixed vapor is flowing will be explained. As is already clear, the mixed vapor branches into the gap B and the inside of the inner cylinder 6 in the mixer 3 and flows out without any obstruction.At this time, the mixer 3 is designed as a kind of flow distributor. The flow of steam does not change significantly depending on the presence or absence of steam to be mixed.

Next, a case where the steam flow rate decreases will be explained.

In general, when the steam flowing in a pipe has a sufficient flow velocity, the flow velocity distribution is as shown in Figure 6a (it shows an approximately uniform distribution, but when the flow velocity decreases, a peak appears in the center as shown in Figure 6b). It is known that the distribution is as follows.

Therefore, when the flow rate of steam to be mixed is small, a larger amount of steam flows into the inner cylinder 6 of the mixer 3.

Similarly, when the flow rate of mixed steam is low, more steam flows into the inner cylinder 6. Therefore, since the two types of steam collide and mix mainly inside the inner cylinder 6, the mixing efficiency does not decrease as much.

When the steam flow rate of either side is small, as can be seen from the above characteristics, the steam on the side with the smaller amount gathers in the center,
This is a desirable form in which the steam on the side with a higher flow rate mixes it so as to envelop it, and is sufficiently mixed by the stirring force of the steam on the side with a higher flow rate.

In the conventional mixer shown in FIGS. 1 and 2, if the mixed steam flow rate is 75 (high), the dimensions of the mixing steam pipe 20 must be made thicker. Therefore, in principle, when the flow rate of mixed steam is large, the conventional mixer cannot be used.

As shown in FIG. 3, the mixer of the present invention has an outer cylinder 5 and an inner cylinder 6.
Since it is installed in the same direction as the flow direction of the steam, it hardly obstructs the flow of the steam to be mixed. In addition, the dimensions of the steam pipe containing the mixer 3 should be selected so that an appropriate flow rate can be obtained for the total steam flow rate after mixing.
, there is no need to make the tube even thicker in order to incorporate the mixer.

Next, in the conventional mixer, the flow rate of the steam to be mixed is small (as a result, the steam branched to the left and right by the mixer flows directly along the pipe wall and flows out without contacting and mixing with the mixed steam.

As explained above, when the flow rate is low, the mixer of the present invention takes advantage of the fact that steam flows mainly through the center and mixes mainly in the center of the tube. (1°) Next, in the conventional mixer, since the mixer has a closed structure, foreign matter mixed in the steam accumulates, so the steam nozzle 4 is There is a risk of blockage.

For this reason, inspection holes or cleaning holes must be provided.

Since the mixer of the present invention has an open structure as shown in FIG. 3, foreign matter mixed into the steam does not accumulate. Therefore, there is no need to provide cleaning holes etc. (The structure is simple and there is no need to worry about accidents such as leakage.

FIG. 5 shows an example in which two mixers of the present invention are used to mix three systems of steam.

It is desirable that one system be the system that is mainly used.

The (1) and (1) systems are mixed into the (1) system using the mixer of the present invention. If the dimensions of the mixing steam pipe are selected so that the steam flow rate after the three systems of steam is mixed is an appropriate flow velocity, and the mixer of the present invention is installed on this pipe, the mixer can be easily housed in the steam pipe system. I can do it.

If the number of mixing systems increases further, the dimensions of the mixing steam pipes may be appropriately selected in accordance with the amount of mixed steam, and the mixer of the present invention may be installed therein.

[Brief explanation of drawings]

1 and 2 are a cross-sectional view and an elevation view, respectively, of a conventional steam mixer; FIGS. 3 and 4 are a cross-sectional view and an elevation view, respectively, of a steam mixer according to the present invention; and FIG. 6 is a connection diagram of a mixer for mixing three systems of steam using the mixer according to the present invention, and FIGS. 6a and 6b are flow velocity distribution diagrams of steam flowing in the pipes, respectively. 1. Steam pipe to be mixed, 2. Mixing steam pipe, 3. Mixer, 4. Fumarole hole, 5. Outer cylinder, 6. Inner cylinder.

Claims (1)

[Claims] In a steam mixer having a steam mixing pipe and a mixing steam pipe perpendicular to the steam mixing pipe, an outer cylinder and an inner cylinder with both ends open are arranged at a distance from each other in the steam mixing pipe, and the Steam, characterized in that a mixing steam pipe is inserted, and a blowhole is provided around the inner cylinder, through which the steam introduced from the mixing steam pipe through the space between the inner and outer cylinders is ejected to the mixed steam. mixer.