Claims:We Claim:

1. A vane type separator for separating liquid droplets from steam-liquid or gas-liquid mixture, the vane type separator comprising a stack of plurality of vanes closely arranged together to form a plurality of flow path for stream of steam/gas-mist mixture, each vane of the plurality vanes having multiple bends to form any one of wave and saw tooth shaped flow paths, Characterized in that the flow path is divided into two equal channels by using a partitioning member.

2. The vane type separator as claimed in claim 1, wherein the partitioning member is a plate.

3. The vane type separator as claimed in claim 1, wherein the flow path is divided in two equal channels from at least second bend.

3. The vane type separator as claimed in claim 1, wherein total number of bends in the flow path are two or more.

4. The vane type separator as claimed in claim 1, wherein the two channels formed by the partitioning member are further divided into two equal channels by using a pair of partition plates from the subsequent bend in flow direction.

5. The vane type separator as claimed in claim 1, wherein the vanes are made of corrugated plates.
, Description:Field of the invention:
The present invention relates to separators for the removal of liquid particles entrained in steam/gaseous streams, and more particularly, the present invention relates to vane type separator for separating liquid droplets from steam-liquid or gas-liquid mixture.
Background of the invention:
In every process, involving contact between liquid and flowing steam/gas or in case of saturated steam generation, the tiny mist droplets are entrained with the steam/gas or the steam. Mist separators have been developed during past few decades to separate undesirable mist before the steam/gas flows to other downstream systems. The mist separators have been used to remove liquid mist from the steam/gas and liquid mixture in various applications like in Nuclear Power Generation to obtain steam/gaseous phase with desired purity. Hence, the mist separators are highly useful in different applications for improvement of product purity, reduction of downstream erosion/corrosion, increasing recovery of valuable liquids and reduction of environmental pollution. The mist separators are also applicable for scrubbing, absorption, stripping or distillation columns, ammonia plants, steam/gas dehydration plants, marine, power plants, food processing industry and many applications where contact between steam/gas and liquid/solids happens.
Prior art provides certain process based on the characteristic of adherence of liquid droplets or mist to the separator surface. There are three main varieties of separators viz. a vane type, a mesh pad type and a fiber candle type based on their principle of operation and applicability. The vane type separator is one of the most commonly used types in process industry.
The vane type separator (90), in accordance with a prior art is as shown in figure 1 and 2. The vane type separator (90) comprises of a stack of plurality of vanes made of corrugated plates or sheets of metal or any other suitable material. The vanes are closely arranged together to form wave or saw-shaped plurality of flow paths with inlets (10) and outlets (20). Specifically, multiple bends (1 to 7) are formed inside a flow path configuration (40) generated by two closely arranged vanes. A stream of steam/gas-mist mixture flows through the flow paths from the inlets (10) to the outlets (20). The mist (liquid) gets separated and is removed from the bottom end (30) of the separator. Mist separation efficiency, pressure drop and tendency of fouling due to liquid droplets are important performance parameters of the vane type separator (100).
The mist separation efficiency for the vane configuration is directly proportional to the number of bends, width of baffle and droplet size.. Hence, the mist separation efficiency can be improved by increment in the number of bends. On the contrary, the increment in the number of bends leads to the increment in pressure drop and overall size of the vane type separator. The increment in the width of baffle (w) also results into increase in the size of the vane type separator. The mist separation efficiency is inversely proportional to the spacing between two vane plates (b).Thus, mist separation efficiency is also increased by reducing the vane gap (b). However, decrease in the vane gap (b) also leads to higher pressure drop and increased tendency for fouling. This conflicting behavior of various design parameters with respect to the separation efficiency, pressure drop and fouling behavior of separator results in to limitations on the performance and configuration of prior art.. It also limits the extent of size reduction of separator during its design.
Accordingly, there exists a need to provide a vane type liquid separator that overcomes the above-mentioned drawbacks.
Object of the invention:
An object of the present invention is to separate mist from a stream of steam/gas-mist mixture.
Another object of the present invention is to achieve maximum specific mist separation efficiency, minimum pressure drop as well as better fouling resistance.
Yet another object of the present invention is to provide a compact mist separator with better performance.
Summary of the invention
Accordingly, the present invention provides a vane type separator for separating liquid droplets from steam/gas-liquid mixture. The vane type separator comprising a stack of plurality of vanes closely arranged together to form a plurality of flow path for stream of steam/gas-mist mixture. Specifically each vane of the plurality vanes includes multiple bends to form any one of wave and saw tooth shaped flow paths. The vane type separator is characterized by that the flow path is divided into two equal channels by using a partitioning member. In an embodiment, the partitioning member is plate.

Typically, wherein the flow path is divided in two equal channels from at least second bend.

Typically, wherein total number of bends in the flow path are two or more

Typically, wherein the two channels formed by the partition plate are further divided into two equal channels by using a pair of partitioning member from third bend.

Brief description of the drawings:
The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows a vane type liquid separator in accordance with a prior art,
Figure 2 shows a schematic of flow path of the vane type liquid separator in accordance with the prior art,
Figure 3 shows a perspective view of a vane type liquid separator in accordance with the present invention,
Figure 4 shows a schematic of flow path of the vane type liquid separator in accordance with the present invention.
Detailed Description of the invention:
The foregoing objects of the invention are accomplished, and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiments.
The present invention provides a compact vane type liquid separator for separating liquid droplets from steam/gas-liquid mixture with better mist separation efficiency. The vane type liquid separator works with a principle of inertial impaction for the mist elimination by employing closely arranged separation surfaces forming a wave or saw tooth shaped flow paths and variable gaps between two surfaces along the flow path to achieve more efficiency with the progression of the flow passage.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures.
Referring to the figures from 3 to 4, there is shown a vane type separator for separating liquid droplets from steam/gas-liquid mixture (hereinafter referred to as “the separator (100)”), in accordance with the present invention.
The separator (100) comprises a stack of plurality of vanes (hereinafter referred to as “the vanes”) closely arranged together to form a plurality of flow path (50) (herein after referred to as “the flow paths”) for stream of steam/gas-mist mixture. In an embodiment, the gap between vanes is to be maintained by spacers or any other suitable arrangement.
The flow paths (50) of the plurality of vanes are provided with an inlet (10) an outlet (20) allowing a stream of steam/gas-mist mixture to flow from one point to another as shown in figure 3. The vanes are closely arranged together with multiple bends (1 to 7) to form a wave or saw tooth shaped flow paths. In an embodiment, the flow path (50) includes two or more bends. The bends shown herein are for purpose of the explanation and it may be evident to those skilled in the art that more than 7 bend can be provided.
A first flow path (50) is formed inside the vane by two closely arranged vanes. Thus stream of steam/gas-mist mixture flows through the flow path (50) from the inlet (10) to the outlet (20). Specifically, the vanes are made of corrugated plates. In alternative embodiment, the vanes are made of sheets of metal or any other suitable material. The separated mist (liquid) is removed from the bottom end (30).
In preferred embodiment, the flow path (50) is divided into two equal channels by using a partitioning member (80). In an embodiment, the partitioning member (80) is plate. The partitioning member (80) is attached to the vanes by screwing or putting a spacer. However, it may be evident to those skilled in the art to form a vanes and partitioning member (80) as a single unit.
In an embodiment of the present invention, the flow path (50a) is divided into two equal channels by using a partition plate (80) as shown in figure 4. The flow path (50a) is divided from the bend number (3), such that a reduction in the vane gap is achieved from the bend number (3). In the embodiment, total number of bends in the flow path (50a) is seven. From the bend number (3), the mist particle size and mist content in the flow is comparatively smaller. However, there is a probability of increase in the pressure drop in the flow path (50a). Thus the partitioning improves the mist separation efficiency in the flow path (50a). In the embodiment, the partition plates (80) are thin plates of any suitable material.
From the bend number (3), the mist droplet size and mist content in the flow is smaller. Thus, dividing the flow from the third bend will have lesser effect to increase pressure drop or tendency of fouling. At the same time, such division of the flow helps in increasing separation at region with smaller mist droplet size.
In another embodiment of the present invention, the flow path (50b) is divided into two equal channels by using the partition plate (80) from the bend number (3). As the partitioning results in the improvement of the mist separation efficiency, total number of bends in the flow path (50b) can be reduced to six. Thus the reduction in total number of bends results in to considerable reduction in overall pressure drop inside the flow path (50b) by nullifying the effect of pressure drop increment due to the provision of the partition plate (80).
In yet another embodiment, the flow path (50c) is divided into two equal channels by using the partition plate (80) from the bend number (3). These two channels are further divided into two equal channels by using another pair of partition plates (80a, 80b) from the bend number (5). Hence, the flow path (50c) is divided into four equal channels from the bend number (5) by using three partition plates (80, 80a, 80b). Hence, the total number of bends in the flow path (50c) is reduced to five thus resulting in substantial increase in the efficiency. By partitioning the flow path (50c) into two small channels at one point and are again partitioning in succession along with the reduction in the total number of bends in the flow path (50c) improves the mist separation efficiency in a considerable amount. This also facilitates an effective reduction in the pressure drop in the flow path (50c). Also, as the partition plates (80a, 80b) are introduced at the outlet side of the flow path (50c) that have only smaller droplets, the partitioning doesn’t results in increased fouling tendency.
Again referring to the figures from 3 to 4, an operation of the vane type liquid separator in accordance with the present invention is described. A plurality of vanes are stalked together to form a plurality of flow paths (50) for steam/gas-mist mixture. The flow path is formed by a close arrangement of adjacent vanes and is provided with multiple bends (1, 2, 3, 4, 5, 6, and 7). The steam/gas-mist mixture flows through the flow paths from an inlet (10) to an outlet (20).
Mist separation takes place by the principle of inertial impaction. As per the principle, change in flow direction makes liquid droplets contained in the steam/gas to impact the vanes. These droplets accumulate to form bigger droplets and get separated from the steam/gas stream. The bends (1 to 7) inside the flow path configuration (50) assist to increase the efficiency as mist droplets that are yet to be captured face the next bend for repetition of the mist separation process.
During the travel through the flow path, bigger droplets of the mist get separated first and the remaining mist with smaller droplets gets separated in later stages of the separator. The removal of smaller droplets occurs less effectively due to their lower inertia as compared to larger size droplets. Thus the separation efficiency of the separator is mainly governed by effective separation of smaller droplets. On the other hand, the pressure drop and fouling effect is governed by existence of larger mist droplets within specific vane gap.
Based on these phenomena, the mist separation efficiency of the separator (100) is improved even with reduction in the pressure drop and fouling effect by effective removal of larger and smaller droplets at different stages along the vane passage. The effective removal of smaller droplets can be achieved by provision of reduced distance between two corrugated plates. However, provision of reduced distance between two vanes would result in increase in the pressure drop and fouling. Thus, the reduction in the vane gap is carried out selectively along the direction of the steam/gas-mist mixture flow in the separator where the flow is free from larger size droplets. Various embodiments of the present invention focus on the various configurations of the flow paths (50) in the separator. In order to carry out the reduction in the vane gap, the flow paths (50) are divided selectively by using partition member (80).
Advantages of the invention
1. The selective partitioning of the flow path (50) achieves higher performance with higher mist separation efficiency and lower pressure drop or without increasing pressure drop and without increasing fouling tendency as compared to the prior art configuration.
2. The overall equipment size of the separator gets reduced, thus reduces the space required to accommodate the separator.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the present invention.