Intelligent liquid distribution apparatus for falling film evaporator and method of using the same

Abstract

The application discloses an intelligent liquid distribution equipment for falling film evaporators and a use method thereof, and comprises a shell, a feeding pipe, a primary liquid distribution unit, a pressurizing unit, an intelligent liquid distribution distribution unit, a tube bank and a discharging pipe arranged in the shell from top to bottom in sequence; the feeding pipe is connected with the primary liquid distribution unit, the primary liquid distribution unit is connected with the pressurizing unit, the pressurizing unit is connected with the intelligent liquid distribution distribution unit, the intelligent liquid distribution distribution unit distributes liquid to the tube bank, and the tube bank is connected with the discharging pipe. The application can uniformly distribute liquid film regardless of whether the liquid of the liquid distributor is stable, can intelligently adjust the liquid distribution flow size, can effectively utilize steam preheating, and can avoid the influence of steam on the liquid film.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of falling film evaporators, in particular to an intelligent liquid distribution device for a falling film evaporator and a method for using the same. BACKGROUND

[0002] Among thin film evaporators, falling film evaporators are known for their excellent evaporation efficiency. They, along with two other types of thin film evaporators (rising film evaporators and wiped film evaporators), form the three main categories of thin film evaporators. In particular, vertical falling film evaporators are a type of falling film evaporator that is widely used in various industrial fields, including chemical industry, light industry, synthetic fibers, food processing, pharmaceuticals, seawater desalination, wastewater treatment, and metal smelting, due to their outstanding performance characteristics, such as high heat transfer efficiency, rapid heating of materials, gentle handling of sensitive materials to prevent decomposition, low pressure loss, low heat loss caused by small temperature differences, significant energy-saving effects, strong anti-fouling ability, and low internal liquid holdup.

[0003] A vertical falling film evaporator outside the tube is disclosed in Chinese patent document CN114191830A, which includes an outer shell; a material inlet channel is provided at the top of the outer shell; a material outlet channel is provided at the bottom of the outer shell; a distribution disc and a falling film evaporation unit are sequentially arranged inside the outer shell in the downward direction of the material inlet channel; the falling film evaporation unit includes a first tube plate, a second tube plate, and at least one single-head heat exchange tube.

[0004] Chinese patent document CN105890238A discloses a vertical falling film evaporator with a new type of liquid distribution device, which includes an evaporator upper end, an evaporator main body part, and an evaporator lower end. The evaporator upper end has a water path; the evaporator main body part includes a layered and parallel arrangement of a refrigerant inlet liquid flute-shaped pipe, a new type of liquid distribution disc, etc., and a suitable refrigerant distributor is provided inside the main body, so that the refrigerant can be uniformly distributed to the surface of the tube bundle and fully contact the surface of the tube bundle; a refrigerant sedimentation liquid return device is provided at the bottom of the main body; the evaporator lower end is used for the water path and the removal of sediment.

[0005] The main function of a vertical falling film evaporator is to form a thin film of liquid on the tube wall and evaporate it. Its working efficiency and operating characteristics largely depend on the uniform distribution of the liquid. This means that the liquid needs to be evenly distributed to each heat exchange tube and form a stable and uniform thin film on the tube wall. The rationality of the design of the liquid distribution device is crucial to the uniform distribution of the liquid. Uneven distribution can cause some areas to dry out, while some areas may have too much flow, resulting in a thick film, affecting heat exchange efficiency; too little flow can cause dryness. Therefore, the design of the distributor has a direct impact on the thermal efficiency and operating stability of the evaporator, and thus affects the production efficiency, product quality, and service life of the equipment.

[0006] An ideal liquid distributor should have characteristics that are not sensitive to liquid layer height changes, and can uniformly distribute liquid, stabilize film formation, have greater operational flexibility, low pressure loss, and is not prone to clogging. However, once a conventional falling film evaporator is designed and manufactured, its film formation flow is usually fixed, and needs to be adjusted by stopping and disassembling, and thus cannot be adjusted online, so it cannot meet the above ideal characteristics. SUMMARY

[0007] In order to overcome the shortcomings of the prior art, the present application provides an intelligent liquid distribution device for a falling film evaporator and a method for using the same, so that uniform film distribution can be achieved regardless of whether the liquid to the liquid distributor is stable, secondly, the liquid distribution flow can be intelligently adjusted, and the steam can be effectively utilized for preheating while avoiding the influence of the steam causing uneven film distribution.

[0008] The technical solutions of the present application are as follows:

[0009] An intelligent liquid distribution device for a falling film evaporator, comprising a shell and, arranged in the shell from top to bottom, a feed pipe, a primary liquid distribution unit, a booster unit, an intelligent liquid distribution distribution unit, a tube bank, and a discharge pipe.

[0010] The feed pipe is connected to the primary liquid distribution unit, the primary liquid distribution unit is connected to the booster unit, the booster unit is connected to the intelligent liquid distribution distribution unit, the intelligent liquid distribution distribution unit distributes liquid to the tube bank, and the tube bank is connected to the discharge pipe.

[0011] As a preferred technical solution of the present application, the primary liquid distribution unit comprises a liquid distribution disc and a plurality of liquid outlets arranged at the bottom of the liquid distribution disc, the liquid distribution disc receives liquid from the feed pipe, and the liquid flows to the booster unit through the plurality of liquid outlets.

[0012] As a preferred technical solution of the present application, the booster unit comprises a reducer and a booster pump, the large opening at the upper part of the reducer is connected to the corresponding liquid outlet of the liquid distribution disc, and the small opening at the lower part of the reducer is connected to the booster pump.

[0013] Further, the booster pump is a variable frequency pump, which can control the number of revolutions to adjust the flow and pressure.

[0014] As a preferred technical solution of the present application, the intelligent liquid distribution distribution unit comprises a liquid storage disc and a plurality of liquid distribution pipes connected to the liquid storage disc, and an adjusting valve, a flow meter, and a matching port are sequentially arranged on each liquid distribution pipe.

[0015] The liquid storage disc is used to store high-pressure flow from the booster pump, and the matching port is connected to the tube bank.

[0016] As a preferred technical scheme of the present application, the regulating valve adopts pid control, and the valve opening of the regulating valve is adjusted according to the flow size of the flowmeter; when the flowmeter indicates that the flow is too large, the regulating valve reduces the valve opening; and when the flowmeter indicates that the flow is too small, the regulating valve increases the valve opening, so as to ensure that the liquid fills in the liquid distribution pipe.

[0017] As a preferred technical scheme of the present application, each matching port is connected with a plurality of falling film reboiler ports in the column tube.

[0018] The use method of the intelligent liquid distribution equipment includes the following steps.

[0019] In the primary liquid distribution unit, the liquid distribution disc receives liquid from the previous system through the feed pipe, and a certain height of liquid level is formed in the liquid distribution disc; the liquid is sent to the corresponding booster unit through a plurality of liquid outlet ports.

[0020] In the booster unit, the liquid enters the booster pump through the reducing pipe, and the liquid is pressurized by the booster pump and sent to the intelligent liquid distribution and distribution unit.

[0021] In the intelligent liquid distribution and distribution unit, the high-pressure liquid enters the liquid storage disc, the regulating valve adopts pid control, and the valve opening is adjusted according to the flow size of the flowmeter, so as to ensure that the liquid fills in the liquid distribution pipe; and finally the liquid flows to the column tube through the matching port.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1. The primary liquid distribution unit and the booster unit are arranged, so that the liquid distribution disc does not need to be ensured to be completely horizontal; secondly, the booster unit ensures uniform distribution of the liquid, and the liquid flow regulation range is larger.

[0024] 2. The primary liquid distribution unit, the booster unit and the intelligent liquid distribution and distribution unit can adjust the liquid film flow in the evaporation pipe online, which is beneficial to adapt to the change of the flow, and when the film flow in the evaporation pipe does not meet the requirements, the evaporation pipe can be adjusted online without stopping the machine, and the operation of the evaporator is continuous. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0026] Fig. 1 The present application is a kind of intelligent liquid distribution equipment for falling film evaporator overall structure schematic view.

[0027] Fig. 2 This is a partial schematic diagram of the primary liquid distribution unit, the pressurization unit, and the intelligent liquid distribution unit in an embodiment of the present invention.

[0028] Fig. 3 This is an overall schematic diagram of the primary liquid distribution unit, the pressurization unit, and the intelligent liquid distribution unit in an embodiment of the present invention.

[0029] In the diagram: 1. Feed pipe; 2. Shell; 31. Liquid distribution tray; 32. Liquid outlet; 33. Reducer; 34. Booster pump; 35. Storage tray; 36. Liquid distribution pipe; 37. Regulating valve; 38. Flow meter; 39. Matching port; 4. Tube set; 5. Discharge pipe. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that, unless otherwise specified, the features in the following embodiments and implementation methods can be combined with each other.

[0032] like Figs. 1-3 As shown, an intelligent liquid distribution device for a falling film evaporator includes a feed pipe 1, a shell 2, tubes 4, a discharge pipe 5, a primary liquid distribution unit, a pressurization unit, and an intelligent liquid distribution unit.

[0033] The feed pipe 1 is connected to the primary liquid distribution unit, which is connected to the pressurization unit. The pressurization unit is connected to the intelligent liquid distribution unit, which distributes the liquid to the tube 4. The tube 4 is connected to the discharge pipe 5. The feed pipe 1, tube 4, discharge pipe 5, primary liquid distribution unit, pressurization unit, and intelligent liquid distribution unit are all contained within the housing 2.

[0034] The primary liquid distribution unit is designed with a liquid distribution tray 31, and several liquid outlets 32 are designed at the bottom of the liquid distribution tray. The liquid distribution tray 31 can receive liquid from the front system, and the liquid can flow to the liquid outlets 32.

[0035] The booster unit is designed with a reducing pipe 33 and a booster pump 34. The larger end of the reducing pipe 33 is connected to the liquid distribution plate 31, and the smaller end is connected to the booster pump 34. The booster pump 34 can deliver liquid and increase pressure. The booster pump 34 is a variable frequency pump, which can control the speed to regulate the flow rate and pressure.

[0036] The intelligent liquid distribution unit is designed with a liquid storage tray 35, which is distributed with several liquid distribution pipes 36. The liquid distribution pipes 36 are connected to a regulating valve 37, a flow meter 38 and a matching port 39.

[0037] The liquid storage tray 35 can store the high-pressure flow from the booster pump 34.

[0038] The regulating valve 37 can adjust the valve opening according to the flow size of the flow meter 38, and when the flow meter 38 indicates too large, the regulating valve 37 reduces the valve opening, and when the flow meter 38 indicates too small, the regulating valve 37 increases the valve opening, so as to ensure that the liquid fills in the liquid distribution pipe 36.

[0039] The matching port 39 is connected to the tube of the falling film reboiler, and one matching port can be connected to several falling film reboiler tube openings.

[0040] The use method of the intelligent liquid distribution device comprises the following steps:

[0041] S1, in the primary liquid distribution unit, the liquid distribution tray 31 receives the liquid from the front system through the feed pipe 1, and forms a certain height of liquid level in the liquid distribution tray 1, and the liquid is sent to the corresponding booster unit through the liquid outlet 32;

[0042] S2, in the booster unit, the liquid enters the booster pump 34 through the reducing pipe 3, and the liquid is pressurized by the booster pump 34 and is sent to the intelligent liquid distribution and distribution unit;

[0043] S3, in the intelligent liquid distribution and distribution unit, the high-pressure liquid enters the liquid storage tray 35, the regulating valve 37 adopts pid control, adjusts the valve opening according to the flow size of the flow meter 38, and ensures that the liquid fills in the liquid distribution pipe 36; finally, the liquid flows to the tube 4 through the matching port 36.

[0044] The primary liquid distribution unit and the booster unit are arranged, so that the liquid distribution tray does not need to be ensured to be completely horizontal; secondly, the booster unit ensures uniform distribution of the liquid, and the liquid flow regulation range is larger.

[0045] The primary liquid distribution unit, the booster unit and the intelligent liquid distribution and distribution unit can adjust the liquid film flow in the evaporation pipe online, on the one hand, it is beneficial to adapt to the change of flow, and on the other hand, when the film flow in the evaporation pipe does not meet the requirements, it can be adjusted online without stopping work and disassembling, and the operation of the evaporator has continuity.

[0046] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. An intelligent liquid distribution apparatus for falling film evaporator characterized in that, The shell (2) and the feed pipe (1), the primary liquid distribution unit, the pressure boosting unit, the intelligent liquid distribution distribution unit, the column tube (4) and the discharge pipe (5) arranged in the shell (2) from top to bottom in sequence; The feed pipe (1) is connected with the primary liquid distribution unit, the primary liquid distribution unit is connected with the pressure boosting unit, the pressure boosting unit is connected with the intelligent liquid distribution distribution unit, the intelligent liquid distribution distribution unit distributes liquid to the column tube (4), and the column tube (4) is connected with the discharge pipe (5); The primary liquid distribution unit comprises a liquid distribution disc (31) and a plurality of liquid outlet ports (32) arranged at the bottom of the liquid distribution disc (31), the liquid distribution disc (31) receives liquid from the feed pipe (1), and the liquid flows to the pressure boosting unit through the plurality of liquid outlet ports (32); The pressure boosting unit comprises a variable diameter pipe (33) and a pressure boosting pump (34), the large opening of the upper portion of the variable diameter pipe (33) is connected with the corresponding liquid outlet port (32) of the liquid distribution disc (31), and the small opening of the lower portion of the variable diameter pipe (33) is connected with the pressure boosting pump (34); the pressure boosting pump (34) is a variable frequency pump, so that the number of revolutions is controlled to adjust the flow and the pressure; The intelligent liquid distribution distribution unit comprises a liquid storage disc (35) and a plurality of liquid distribution pipes (36) connected with the liquid storage disc (35), an adjusting valve (37), a flow meter (38) and a matching port (39) are sequentially arranged on each liquid distribution pipe (36); the liquid storage disc (35) is used for storing high-pressure flow from the pressure boosting pump (34), and each matching port (39) is connected with a plurality of falling film reboiler pipe openings in the column tube (4); The adjusting valve (37) is controlled by PID, and the valve opening degree of the adjusting valve (37) is adjusted according to the flow size of the flow meter (38); when the flow meter (38) indicates that the flow is too large, the valve opening degree of the adjusting valve (37) is reduced, when the flow meter (38) indicates that the flow is too small, the valve opening degree of the adjusting valve (37) is increased, so that the liquid in the liquid distribution pipe (36) is ensured to be filled.

2. The method of using the smart fluid distribution device of claim 1, wherein, The method comprises the following steps: S1, in the primary liquid distribution unit, the liquid distribution disc (31) receives liquid from the previous system through the feed pipe (1), a certain height of liquid level is formed in the liquid distribution disc (31), and the liquid flows to the corresponding pressure boosting unit through the plurality of liquid outlet ports (32); S2, in the pressure boosting unit, the liquid enters the pressure boosting pump (34) through the variable diameter pipe (33), the liquid is pressurized by the pressure boosting pump (34) and is delivered to the intelligent liquid distribution distribution unit; S3, in the intelligent liquid distribution distribution unit, the high-pressure liquid enters the liquid storage disc (35), the adjusting valve (37) is controlled by PID, the valve opening degree is adjusted according to the flow size of the flow meter (38), and the liquid in the liquid distribution pipe (36) is ensured to be filled; finally, the liquid flows to the column tube (4) through the matching port (39).

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