Gas-liquid separation structure for falling film evaporator

Abstract

The utility model discloses a gas-liquid separation structure for a falling film evaporator, which comprises a barrel, a heat exchange tube arranged at the lower part in the barrel, a liquid distribution box arranged in the barrel above the heat exchange tube, a gas-liquid separation shell arranged in the barrel above the liquid distribution box, and a separation space formed by the circumferential wall surface of the gas-liquid separation shell and the barrel, a through hole channel is formed in the side wall of the gas-liquid separation shell, and a gas outlet pipe is mounted on the wall of the cylinder at the top of the separation space in a communicating manner; the liquid inlet pipe is communicated to the liquid distribution box; liquid fluid enters the liquid distribution box from the liquid inlet pipe and is evaporated into steam after being uniformly distributed, the steam enters the gas-liquid separation shell through the hole channel, liquid drops settle in the gas-liquid separation shell, and the steam is discharged from the gas outlet pipe, so that gas-liquid separation is realized, the steam purity of the falling film evaporator is effectively improved and ensured, and meanwhile, the steam pressure drop is reduced.

Description

Technical Field

[0001] This utility model relates to the field of evaporator technology, and in particular to a gas-liquid separation structure for a falling film evaporator. Background Technology

[0002] Falling film evaporators are highly efficient evaporation devices widely used in evaporation concentration and evaporation crystallization. However, steam entrainment of liquid droplets (mist entrainment) poses a critical problem affecting equipment efficiency and product quality. Furthermore, if steam enters the compressor, there is a potential risk of droplet corrosion of the impeller.

[0003] In existing falling film evaporators, gas-liquid separation mainly relies on gravity settling and the addition of baffles. However, natural settling requires a large separation space, increasing the size and cost of the equipment; adding baffles results in a large pressure drop, affecting the system vacuum and leading to poor separation of small droplets. Utility Model Content

[0004] To address the aforementioned issues, this application provides a rationally designed gas-liquid separation structure for falling film evaporators, thereby achieving gas-liquid separation, effectively improving and ensuring the steam purity of the falling film evaporator, while simultaneously reducing steam pressure drop.

[0005] The technical solution adopted in this utility model is as follows:

[0006] A gas-liquid separation structure for a falling film evaporator includes a cylindrical body, with heat exchange tubes arranged at the lower part of the cylindrical body, a liquid distribution box arranged in the cylindrical body above the heat exchange tubes, and a gas-liquid separation shell installed in the cylindrical body above the liquid distribution box. The circumferential wall of the gas-liquid separation shell is fitted with the cylindrical body to form a separation space, and a through-hole is opened on the side wall of the gas-liquid separation shell. An exhaust pipe is connected and installed on the cylindrical wall at the top of the separation space. It also includes a liquid inlet pipe connected to the liquid distribution box.

[0007] As a further improvement to the above technical solution:

[0008] The cylinder is a horizontally arranged cylindrical structure, and the gas-liquid separation shell is installed on the top wall of the cylinder along the axial direction; the gas outlet pipe and the channel are respectively located at both ends of the gas-liquid separation shell.

[0009] A wire mesh demister is installed inside the gas-liquid separation housing located between the gas outlet pipe and the channel. The wire mesh demister divides the separation space into two parts.

[0010] The dimensions of the channels gradually decrease along the direction toward the vent pipe, with the channel furthest from the vent pipe having the largest dimension and the channel closest to the vent pipe having the smallest dimension.

[0011] The structure of the gas-liquid separator shell is as follows: it includes a bottom plate, side plates are installed on opposite long sides of the bottom plate, and end plates are installed on opposite short sides of the bottom plate. The edges of adjacent side plates and end plates are connected, and the top edges of the side plates and end plates are attached to the top surface of the inner cylinder. The side plates are provided with channels.

[0012] The two side panels have an outward-sloping structure that tilts upwards and outwards.

[0013] The inclination angle of the side plate is 40°-50°.

[0014] The base plate has through holes at both ends.

[0015] The horizontally arranged liquid distribution tanks are spaced apart from the inner wall of the cylinder.

[0016] The liquid inlet pipe is located in the middle of the top surface of the cylinder. The liquid inlet pipe passes through the cylinder and the gas-liquid separation shell in sequence and then connects to the liquid distribution box.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] In this invention, liquid fluid enters the liquid distribution box through the inlet pipe, is evenly distributed, and is evaporated into steam. The steam enters the gas-liquid separation shell through the channel, where liquid droplets settle and the steam is discharged from the outlet pipe, thus achieving gas-liquid separation. The overall structure is simplified, compact, and effectively improves and ensures the steam purity of the falling film evaporator, solves the problem of liquid entrainment in steam, and reduces steam pressure drop.

[0019] This utility model also has the following advantages:

[0020] The outlet pipe and the channel are located at both ends of the gas-liquid separation shell, thereby extending the steam flow path in the gas-liquid separation shell, increasing the chance of droplet impact and separation, and helping to improve and ensure the sedimentation of droplets.

[0021] The size of the orifice gradually decreases along the direction towards the outlet pipe. By setting the orifice size inversely proportional to the distance from the outlet pipe, the resistance in the steam flow is reduced, allowing large droplets to settle smoothly. At the same time, by reducing the orifice size near the outlet pipe, the steam turbulence is gradually increased, promoting the coalescence and settling of small droplets.

[0022] A wire mesh demister is installed between the outlet pipe and the channel. The wire mesh demister can intercept residual tiny droplets, thereby achieving graded interception of droplets in the steam and ensuring the overall purity of the steam. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the present invention along its longitudinal section.

[0024] Figure 2This is a cross-sectional view of the present invention.

[0025] Figure 3 for Figure 2 A magnified view of a portion of point A in the middle.

[0026] Figure 4 This is a schematic diagram showing the layout of the gas-liquid separation shell, liquid inlet pipe, and liquid distribution box of this utility model.

[0027] The components include: 1. cylinder; 2. heat exchange tubes; 3. liquid distribution box; 4. gas-liquid separation shell; 5. liquid inlet pipe; 6. wire mesh demister; 7. gas outlet pipe.

[0028] 41. Side plate; 42. End plate; 43. Bottom plate; 411. Channel; 431. Through hole. Detailed Implementation

[0029] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0030] like Figure 1 and Figure 2 As shown, a gas-liquid separation structure for a falling film evaporator in this embodiment includes a cylindrical body 1, a heat exchange tube 2 arranged at the lower part of the cylindrical body 1, a liquid distribution box 3 arranged inside the cylindrical body 1 above the heat exchange tube 2, a gas-liquid separation shell 4 installed inside the cylindrical body 1 above the liquid distribution box 3, the circumferential wall of the gas-liquid separation shell 4 is fitted with the cylindrical body 1 to form a separation space, a through hole 411 is opened on the side wall of the gas-liquid separation shell 4, and an exhaust pipe 7 is connected and installed on the cylindrical wall of the cylindrical body 1 at the top of the separation space; it also includes an inlet pipe 5 connected to the liquid distribution box 3.

[0031] In this embodiment, the liquid fluid enters the liquid distribution box 3 from the liquid inlet pipe 5, and after being evenly distributed, it is evaporated into steam. The steam enters the gas-liquid separation shell 4 through the channel 411. The liquid droplets settle in the gas-liquid separation shell 4, while the steam is discharged from the gas outlet pipe 7, thus realizing gas-liquid separation. The overall structure is simplified, compact and small, thereby solving the problem of steam entrainment of liquid and ensuring steam purity while reducing steam pressure drop.

[0032] The cylinder 1 is a horizontally arranged cylindrical structure. The gas-liquid separation shell 4 is installed on the inner top wall of the cylinder 1 along the axial direction. The separation space is formed at the gas outlet pipe 7 above the liquid distribution box 3, so that the steam is discharged through the gas outlet pipe 7 after gas-liquid separation. The gas outlet pipe 7 and the channel 411 are respectively arranged at both ends of the gas-liquid separation shell 4.

[0033] In this embodiment, the vent pipe 7 and the channel 411 are respectively located at both ends of the gas-liquid separation shell 4, thereby extending the flow of steam in the gas-liquid separation shell 4, increasing the chance of droplet impact and separation, and helping to improve and ensure the sedimentation of droplets.

[0034] like Figure 1and Figure 3 As shown, a wire mesh demister 6 is installed inside the gas-liquid separation housing 4 located between the gas outlet pipe 7 and the channel 411. The wire mesh demister 6 divides the separation space into two parts.

[0035] In this embodiment, a wire mesh demister 6 is provided between the outlet pipe 7 and the channel 411. The wire mesh demister 6 can intercept residual tiny droplets, thereby achieving graded interception of droplets in the steam and ensuring the overall purity of the steam.

[0036] In this embodiment, the wire mesh demister 6 is set between the channel 411 and the outlet pipe 7. Steam enters the separation space through the channel 411 and most of the droplets are removed before reaching the wire mesh demister 6. Then, the wire mesh demister 6 intercepts the remaining tiny droplets, which not only achieves the graded interception and separation of droplets, but also effectively reduces or even avoids the clogging of the mesh of the wire mesh demister 6.

[0037] In this embodiment, the wire mesh demister 6 can be a commercially available product. When using it, different specifications of wire mesh demister 6 can be selected based on actual needs, such as steam purity, and considering different mesh sizes, different numbers of wire mesh layers or thicknesses.

[0038] like Figure 4 As shown, the size of the channel 411 gradually decreases along the direction toward the vent pipe 7, with the channel 411 farthest from the vent pipe 7 having the largest size and the channel 411 closest to the vent pipe 7 having the smallest size.

[0039] In this embodiment, the size of the orifice 411 gradually decreases along the direction toward the outlet pipe 7. By setting the inverse proportional relationship between the size of the orifice 411 and the distance to the outlet pipe 7, the resistance in the steam flow is reduced, allowing large droplets to settle smoothly. At the same time, by reducing the size of the orifice 411 near the outlet pipe 7, the steam turbulence is gradually increased, promoting the coalescence and settling of small droplets.

[0040] In this embodiment, the channel 411 can be a plurality of rectangular holes of different sizes opened on the side wall of the gas-liquid separation shell 4.

[0041] The structure of the gas-liquid separation shell 4 is as follows: it includes a bottom plate 43, side plates 41 are respectively installed on the opposite long sides of the bottom plate 43, and end plates 42 are respectively installed on the opposite short sides of the bottom plate 43. The edges of adjacent side plates 41 and end plates 42 are connected, and the top edges of side plates 41 and end plates 42 are attached to the inner top surface of the cylinder 1. A channel 411 is opened on the side plate 41.

[0042] In this embodiment, the top surfaces of the side plate 41 and the end plate 42 can be respectively attached and welded to the inner wall of the cylinder 1, and the side plate 41, the end plate 42 and the bottom plate 43 can be welded together, thereby forming a separation space at the top of the cylinder 1 through the gas-liquid separation shell 4.

[0043] In this embodiment, the edges of the wire mesh demister 6 are welded and fixed to the bottom plate 43, the side plate 41, and the inner wall of the cylinder 1, respectively.

[0044] Of course, in actual operation, the installation of the gas-liquid separation shell 4 relative to the inner wall of the cylinder 1 and the installation of the wire mesh demister 6 can also be carried out in other detachable and universal forms according to actual needs, such as the need to replace the wire mesh demister 6. For example, fasteners such as bolts can be used for fixing, and a concave-convex groove fitting structure can be used to achieve the fixed and detachable installation of the wire mesh demister 6 and the gas-liquid separation shell 4.

[0045] The two side plates 41 have an upward and outward inclined structure, which enables the droplets to flow back along the wall of the side plate 41 and prevents secondary entrainment.

[0046] The tilt angle of the side plate 41 is 40°-50°, such as 45°, which facilitates installation, ensures structural reliability, and ensures smooth backflow guidance of settled droplets.

[0047] In practical use, the specific tilt angle of the side plate 41 can be determined according to actual needs, such as the viscosity and flow characteristics of the liquid fluid.

[0048] The bottom plate 43 has through holes 431 at both ends, so that the liquid that settles in the gas-liquid separation shell 4 can flow down into the evaporator through the through holes 431.

[0049] In this embodiment, the size of the through hole 431 is much smaller than the size of the channel 411. The liquid flows smoothly downward through the through hole 431, reducing or even avoiding the upward flow of steam through the through hole 431.

[0050] The horizontally arranged liquid distribution box 3 has a distance between its circumferential edge and the inner wall of the cylinder 1 to ensure that the steam flows smoothly upward and flows out from the outlet pipe 7 after passing through the gas-liquid separation shell 4.

[0051] The liquid inlet pipe 5 is located in the middle of the top surface of the cylinder 1. The liquid inlet pipe 5 passes through the cylinder 1 and the gas-liquid separation shell 4 in sequence and then connects to the liquid distribution box 3.

[0052] In this embodiment, the liquid inlet pipe 5 can be welded and fixed relative to the gas-liquid separation shell 4.

[0053] In this embodiment, the liquid inlet pipe 5 is installed in the middle of the top surface of the cylinder 1 to help distribute the liquid evenly through the liquid distribution box 3.

[0054] In this embodiment, the arrangement and installation of the cylinder 1 and its internal liquid distribution tank 3 and heat exchange tube 2 can adopt existing conventional structures, such as those shown in the existing invention patent with application number 2019104334964, authorization announcement date of 2021.06.22, and title of horizontal impact falling film evaporator and method; of course, other existing structures can also be adopted.

[0055] The working principle of this utility model is as follows:

[0056] Liquid fluid flows into the distribution box 3 through the inlet pipe 5, and after being evenly distributed by the distribution box 3, it falls and is evaporated into steam by the heat exchange tube 2. The steam rises and enters the gas-liquid separation shell 4 through the orifice 411. By setting the orifice 411 away from the outlet pipe 7, the steam flow is extended, increasing the chance of droplet impact and separation. By gradually reducing the size of the orifice 411 on the side plate 41 towards the outlet pipe 7, the steam flow resistance is reduced, causing large droplets to settle. The orifice near the outlet gradually shrinks, gradually increasing the steam turbulence and promoting the coalescence of small droplets. By tilting the side plate 41 upwards and outwards, the settled droplets can flow back along the wall, preventing secondary entrainment. After most of the droplets have been removed by the side plate 41, a wire mesh demister 6 is added at the end of the steam flow channel for terminal fine filtration. The wire mesh demister 6 intercepts residual tiny droplets, achieving graded interception and separation of droplets of different sizes.

[0057] This invention achieves gas-liquid separation, with a simplified and compact overall structure, effectively improving and ensuring the steam purity of the falling film evaporator, solving the problem of steam entrainment of liquid, and reducing steam pressure drop.

[0058] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0059] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.

Claims

1. A gas-liquid separation structure for a falling film evaporator, comprising a cylindrical body (1), wherein heat exchange tubes (2) are arranged at the lower part of the interior of the cylindrical body (1), characterized in that: A liquid distribution box (3) is arranged inside the cylinder (1) above the heat exchange tube (2). A gas-liquid separation shell (4) is installed inside the cylinder (1) above the liquid distribution box (3). The circumferential wall of the gas-liquid separation shell (4) is attached to the cylinder (1) to form a separation space. A through hole (411) is opened on the side wall of the gas-liquid separation shell (4). An outlet pipe (7) is connected to the cylinder wall of the cylinder (1) at the top of the separation space. It also includes an inlet pipe (5) connected to the liquid distribution box (3).

2. The gas-liquid separation structure for a falling film evaporator as described in claim 1, characterized in that: The cylinder (1) is a horizontally arranged cylindrical structure, and the gas-liquid separation shell (4) is arranged and installed on the inner top wall of the cylinder (1) along the axial direction; the gas outlet pipe (7) and the channel (411) are respectively arranged at both ends of the gas-liquid separation shell (4).

3. A gas-liquid separation structure for a falling film evaporator as described in claim 1 or 2, characterized in that: A wire mesh demister (6) is installed inside the gas-liquid separation housing (4) located between the gas outlet pipe (7) and the channel (411). The wire mesh demister (6) divides the separation space into two parts.

4. The gas-liquid separation structure for a falling film evaporator as described in claim 2, characterized in that: The dimensions of the channel (411) gradually decrease along the direction toward the air outlet pipe (7), with the channel (411) farthest from the air outlet pipe (7) having the largest dimensions and the channel (411) closest to the air outlet pipe (7) having the smallest dimensions.

5. The gas-liquid separation structure for a falling film evaporator as described in claim 1, characterized in that: The structure of the gas-liquid separation shell (4) is as follows: it includes a bottom plate (43), side plates (41) are installed on the opposite long sides of the bottom plate (43), and end plates (42) are installed on the opposite short sides of the bottom plate (43). The edges of adjacent side plates (41) and end plates (42) are connected, and the top edges of side plates (41) and end plates (42) are attached to the inner top surface of the cylinder (1). The side plates (41) are provided with channels (411).

6. The gas-liquid separation structure for a falling film evaporator as described in claim 5, characterized in that: The two side panels (41) have an outward-sloping structure that is inclined upwards and outwards.

7. The gas-liquid separation structure for a falling film evaporator as described in claim 6, characterized in that: The inclination angle of the side plate (41) is 40°-50°.

8. The gas-liquid separation structure for a falling film evaporator as described in claim 5, characterized in that: Through holes (431) are respectively opened at both ends of the base plate (43).

9. The gas-liquid separation structure for a falling film evaporator as described in claim 1, characterized in that: The horizontally arranged liquid distribution box (3) has a distance between its circumferential edge and the inner wall of the cylinder (1).

10. A gas-liquid separation structure for a falling film evaporator as described in claim 1, characterized in that: The liquid inlet pipe (5) is located in the middle of the top surface of the cylinder (1). The liquid inlet pipe (5) passes through the cylinder (1) and the gas-liquid separation shell (4) in sequence and then connects to the liquid distribution box (3).

Images