RU2552479C2 - Perfected apparatus for separation of fluid drops caught by gas or vapour - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to separator of fluid drops caught by gas or vapour flowing through said apparatus. Said separator comprises units of parallel corrugated spaced apart plates. Said units feature the following geometrical characteristics: Wavelength or period of crimps P makes 6-24 mm, while amplitude A equals P/2. Gap G between adjacent corrugated plates in said units equals amplitude A of said crimps.

EFFECT: higher efficiency of drops catching and accumulation by vapour flow through separator, decreased repeated catching for discharge via flutes and drain pipes.

4 cl, 2 dwg

Description

Technical field

The invention relates to an improved apparatus for separating liquid droplets entrained in gas or steam passing through the apparatus. For convenience, such an apparatus will hereinafter be called a liquid separator.

State of the art

Although the objective of a plant producing compressed steam to drive a turbine is to produce 100% dry steam for feeding into the turbine and keep the steam dry throughout the pipe system, this is usually not possible, for example, due to heat loss in the pipes, or in an upstream turbine, a certain amount of steam condenses into water droplets. Since steam turbines are susceptible to erosion and / or corrosion caused by droplets, moisture separators are required to remove droplets of water from the steam before it enters the turbines. Moisture separators are especially needed before steam is fed into the medium and low pressure turbines, as the steam has already been significantly cooled due to expansion through the previous high pressure turbine.

The moisture separator known from US Pat. No. 4,342,570 contains adjacent blocks of spaced, mutually parallel, corrugated plates that are bolted to the support panels. A corrugated plate located upstream of the blocks distributes the incoming wet steam stream evenly. The corrugated plate is also bolted to the support panels. Corrugated plates are positioned so that the corrugations are perpendicular to the direction of steam flow. As a result, the steam quickly deviates alternately in different directions when it flows between adjacent plates along the corrugations so that water droplets, having more inertia than the surrounding steam, are retained by the corrugations instead of being trapped by the steam. The corrugated plates are inclined at an angle to the horizontal so that the captured drops run off along the corrugations into the grooves located to collect water when it flows from each block of corrugated plates. Water is removed from the moisture separator through drain pipes connected to the gutters. Due to the erosion and corrosion problem mentioned above, there is a need to maximize the ability of corrugated plates to effectively capture and collect water droplets entrained by the steam flow through the moisture separator, and to minimize the tendency of trapped and collected water to again be entrained by the steam stream before draining through gutters and drain pipes . For this purpose, the inventors have found that a certain geometric configuration of the corrugations is significantly more effective than others.

Disclosure of invention

In accordance with the present invention, the liquid separator comprises corrugated plates having the following geometric characteristics.

The wavelength or corrugation period P is in the range from 6 mm to 24 mm, and the amplitude A is about P / 2.

In preferred embodiments of the present invention, P ranges from 9 mm to 18 mm.

In addition, it was found that good performance is obtained if the gap G between adjacent corrugated plates in the moisture separator is approximately the same as the amplitude A.

Preferably, the width W of each corrugated plate, measured in the direction of steam flow, is about 10P, and the height H of each corrugated plate, measured in the plane of the plates perpendicular to the steam flow and at right angles to the width W, should be in the range from 0.75W to 1,5W.

The exact dimensions of the above corrugated plates vary within the above ranges in accordance with the conditions that arise in specific steam supply systems in which the plates are used. Optimized values for specific systems are obtained by a combination of analysis using well-known IOP (computational fluid dynamics) programs and test benches.

The following aspects of the disclosure will become apparent from the following description and claims.

Brief Description of the Drawings

Next, preferred embodiments of the present invention will be described by way of example only with reference to the drawings, in which:

FIG. 1 is a plan view of one of the corrugated plates, and

FIG. 2 is a view from the edge of two adjacent plates in plane II-II of FIG. one.

The implementation of the invention

In FIG. 1 shows one embodiment of a corrugated plate 10 for use in a liquid separator. In the plan view, the plate has the shape of a parallelogram having a side of width W and a longer side H / sin α, where H is the height of the parallelogram measured perpendicular to the width W, and α is the acute internal angle formed by the intersection of the sides of the parallelogram. The plate is made of stainless or other high alloy steel to withstand the effects of hot steam S passing along it.

As shown in FIG. 2, the corrugations 12 in this particular embodiment are formed as a series of homogeneous sinusoidal waves along the width W of each plate 10. And although sinusoidal waves are shown, the designer can use other types of waves, such as parabolic, trihedral and even square waves, although it is advisable to round out the angles of the last two types of waves to prevent overload, which can lead to cracking and / or corrosion of the plates.

As shown by arrows S in the embodiment of FIG. 1 and 2, steam passes through a gap G between adjacent plates perpendicular to the lengths of the corrugations, and this deflects the steam alternately in opposite directions when it passes between adjacent plates with corrugations so that water droplets having more inertia than the surrounding dry vapor tend to linger corrugations instead of being carried away by a stream of steam.

It was found that for effective droplet removal, the wavelength or corrugation period P should be in the range from 6 mm to 24 mm, preferably from 9 mm to 18 mm, and the amplitude A should be half the value P. The performance also improves if the gap G, those. the distance between adjacent corrugated plates in the liquid separator is approximately the same as the amplitude A.

In order to easily obtain and keep the size G constant in each block of corrugated plates, four fields 13 are formed on each of the plates 10 during the pressing operation, which forms the corrugations. A pair of fields 13 is located near the front edge of each plate, and another pair of fields is located near the rear edge, the fields of each pair are spaced in the direction across the corrugations. Each field 13 is formed in such a way that a recess connects the two vertices of the corrugations so that the recess of the adjacent plate is located on the field, as shown in FIG. 2.

It should be noted that the steam S passes perpendicular to the lengths of the corrugations, but not at right angles to them. The intersection of the steam flow direction S with the transverse length of the corrugations 12 sharpens the internal angle θ, which in this preferred embodiment is the same as the acute internal angle α formed by the intersection of the sides of the parallelogram. And although it is possible to form a liquid separator in such a way that the steam flows over the corrugations at right angles to the corrugations, it is preferable that the steam flow meets the corrugations at an acute internal angle θ, as shown, since this automatically gives the droplets trapped by the corrugations a velocity component flow in the direction D along the length of the corrugations, which contributes to the advancement of water droplets in the direction of discharge. Of course, the designer himself chooses the deviation angle θ between the steam flow and the longitudinal length of the corrugations, but the design of the moisture separator will be simplified if θ = α.

Drainage is also improved if one end 14 of the corrugations is lower than the other end 15 so that the recesses of each block of corrugated plates merge into the grooves formed at their ends 14.

It should be noted that the front and rear ends 16, 17 of the corrugated plates, respectively, are flat, i.e. without corrugation. They have holes 18 near each corner of the parallelogram shape for inserting support elements of circular cross section (not shown), which help to assemble corrugated plates and save them in one block.

The above description is made by way of example only, modifications are possible within the scope of the appended claims.

Claims (4)

1. A liquid separator containing blocks of parallel corrugated plates located at a distance from each other and having the following geometric characteristics:
the wavelength or corrugation period P is from 6 to 24 mm;
the amplitude A is P / 2, and
the gap G between adjacent corrugated plates in the blocks is equal to the amplitude A of the corrugations. 2. The liquid separator according to claim 1, in which P is from 9 to 18 mm. 3. The liquid separator according to claim 1 or 2, in which the width W of each corrugated plate, measured in the direction of steam flow, is 10 P. 4. The liquid separator according to claim 3, in which the height H of each corrugated plate, measured in the planes of the plates transverse to the steam flow and at right angles to the width W, is from 0.75 W to 1.5 W.

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