Double-effect falling film evaporator maintenance system

Abstract

The utility model discloses a maintenance system for a double-effect falling-film evaporator, which relates to the technical field of double-effect falling-film evaporators and comprises a first-effect falling-film evaporator and a second-effect falling-film evaporator. A low-pressure steam inlet pipeline of the first-effect falling film evaporator is connected with a first blind plate valve; a low-pressure steam inlet pipeline of the first-effect falling film evaporator is connected with a secondary steam inlet pipeline of the second-effect falling film evaporator through a first pipeline, and the first pipeline is connected with a second blind plate valve; and a secondary steam inlet pipeline of the second-effect falling film evaporator is connected with a third blind plate valve. On the premise of ensuring the normal overhaul and processing capacity of the double-effect falling film evaporator, the normal production load of the device is stabilized, and the fluctuation of the device caused by overhaul is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of double-effect falling film evaporators, and particularly relates to a maintenance system for a double-effect falling film evaporator. Background Art

[0002] The falling film evaporation system of the high-saline water device concentrates the influent TDS from 120,000 mg / L to 230,000 mg / L. To save energy consumption, the falling film evaporation system is set as a double-effect. The double-effect falling film evaporator is an efficient evaporation device that combines the falling film evaporation technology and the multi-effect evaporation principle, and is usually used in applications that require high efficiency and energy conservation. This evaporator realizes the reuse of energy by connecting two single-effect evaporators in series, thereby significantly reducing energy consumption and improving the overall economy.

[0003] After the falling film evaporation system operates for a certain period, it needs to be shut down for maintenance due to reasons such as fouling of the heat exchanger. When the double-effect falling film evaporation system is shut down for maintenance, the entire system needs to be shut down, and single-effect falling film evaporation maintenance cannot be realized. The maintenance time required when both effects are shut down is long, and since the upstream and downstream production devices operate continuously during the maintenance period, fluctuations will occur in the upstream and downstream devices during the shutdown of the double-effect falling film evaporation system, which is not conducive to the stable operation of the upstream and downstream. Content of the Utility Model

[0004] To solve the problems of the prior art, the utility model provides a maintenance system for a double-effect falling film evaporator, including: a first-effect falling film evaporator and a second-effect falling film evaporator;

[0005] A first blind valve is connected to the low-pressure steam inlet pipeline of the first-effect falling film evaporator;

[0006] The low-pressure steam inlet pipeline of the first-effect falling film evaporator is connected to the secondary steam inlet pipeline of the second-effect falling film evaporator through a first pipeline, and a second blind valve is connected to the first pipeline;

[0007] A third blind valve is connected to the secondary steam inlet pipeline of the second-effect falling film evaporator.

[0008] Further, a fourth blind valve is connected to the secondary steam outlet pipeline of the second-effect falling film evaporator, and the secondary steam outlet pipeline is also connected to a condenser.

[0009] Further, a second pipeline is connected between the secondary steam outlet pipeline and the secondary steam inlet pipeline of the second-effect falling film evaporator, and a fifth blind valve is connected to the second pipeline.

[0010] The beneficial effects of the technical solution provided by the present utility model are as follows: In the present utility model, the separation of double-effect low-pressure heating steam is achieved through the first blind plate valve and the second blind plate valve, ensuring that the heat source supply of the first effect enters the second-effect falling film evaporator when the first-effect falling film evaporator is shut down for maintenance; the separation of secondary steam is achieved through the third blind plate valve, the fourth blind plate valve, and the fifth blind plate valve, ensuring that the secondary steam of the first effect condenses when the second-effect falling film evaporator is shut down for maintenance, enabling a certain effect in the double-effect to operate during maintenance, ensuring the operation load of the upstream and downstream while ensuring single-effect operation, stabilizing the normal production load of the double-effect falling film evaporator on the premise of ensuring the normal maintenance and processing capacity of the double-effect falling film evaporator, and avoiding fluctuations in the double-effect falling film evaporator caused by maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 FIG. is a schematic structural diagram of a first-effect falling film evaporator in a double-effect falling film evaporator maintenance system provided by the present utility model;

[0012] Figure 2 FIG. is a schematic structural diagram of a second-effect falling film evaporator in a double-effect falling film evaporator maintenance system provided by the present utility model.

[0013] Reference numerals: 1 - first-effect falling film evaporator; 2 - second-effect falling film evaporator; 3 - low-pressure steam inlet pipeline; 4 - first blind plate valve; 5 - first pipeline; 6 - second blind plate valve; 7 - third blind plate valve; 8 - secondary steam inlet pipeline; 9 - exhaust pipeline; 10 - fourth blind plate valve; 11 - second pipeline; 12 - fifth blind plate valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0015] To make the objectives, technical solutions, and advantages of the present utility model clearer, the embodiments of the present utility model will be further described in detail below with reference to the accompanying drawings.

[0016] It should be noted that in this embodiment, the orientation or positional relationship indicated by "bottom", "top", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present application. In addition, the terms "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0017] It should also be noted that in this embodiment, unless otherwise clearly specified and defined, the terms "set" and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0018] See Figure 1 - Figure 2 , a maintenance system for a double-effect falling film evaporator, including a first-effect falling film evaporator 1 and a second-effect falling film evaporator 2. Among them, the first-effect falling film evaporator 1 is the first evaporation unit in the double-effect system. The raw material liquid (usually a solution or a mixture) is heated by the low-pressure steam entering through the low-pressure steam inlet pipeline 3, causing partial evaporation. The raw material liquid enters the evaporator from the top, forms a thin film on the internal tube bundle, and flows downward along the tube wall. Due to the large heat exchange area and the liquid being in a thin film state, the heat transfer efficiency is very high.

[0019] The second-effect falling film evaporator 2 is the second evaporation unit. The steam inlet of the second-effect falling film evaporator 2 is connected to the steam outlet of the first-effect falling film evaporator 1 through the secondary steam inlet pipeline 8. The steam from the first-effect falling film evaporator 1 is reused as a heat source to heat the new raw material liquid, which can further improve the energy efficiency of the system; therefore, the second-effect falling film evaporator not only recovers heat but also reduces the demand for fresh steam.

[0020] The second-effect falling film evaporator 2 is usually connected to a condenser or a vacuum system. The purpose is to handle the new secondary steam generated during the evaporation process and other possible non-condensable gases. The new secondary steam will be sent to the condenser, where it is condensed into a liquid state by a cooling medium (such as cold water). This can not only recover heat but also reduce the impact on the environment; in addition to the new secondary steam, there may be some non-condensable gases (such as air) mixed into the system. These gases cannot be condensed, so they need to be discharged from the system to maintain the vacuum degree inside the evaporator.

[0021] In the prior art, when performing daily maintenance on a double-effect falling film evaporator, it is necessary to shut down the entire double-effect falling film evaporator, unload all the materials inside the evaporator. The shutdown time of the falling film evaporator is long, the maintenance time is long, and the workload is large. When the falling film evaporator is completely shut down, the upstream all feeds are suspended, affecting the load of the upstream and downstream processing devices.

[0022] Therefore, in the present utility model, a first blind plate valve 4 is connected to the low-pressure steam inlet pipeline 3 of the first-effect falling-film evaporator 1. The low-pressure steam inlet pipeline 3 of the first-effect falling-film evaporator 1 is connected to the secondary steam inlet pipeline 8 of the second-effect falling-film evaporator 2 through a first pipeline 5, and a second blind plate valve 6 is connected to the first pipeline 5. The first blind plate valve 4 is located between the connection of the low-pressure steam inlet pipeline 3 and the first pipeline 5 and the low-pressure steam inlet of the first-effect falling-film evaporator 1.

[0023] A third blind plate valve 7 is connected to the secondary steam inlet pipeline 8 of the second-effect falling-film evaporator 2, and a fourth blind plate valve 10 is connected to the secondary steam outlet pipeline 9 of the second-effect falling-film evaporator 2. The secondary steam outlet pipeline 9 is also connected to a condenser. A second pipeline 11 is connected between the secondary steam outlet pipeline 9 and the secondary steam inlet pipeline 8 of the second-effect falling-film evaporator 2, and a fifth blind plate valve 12 is connected to the second pipeline 11; the third blind plate valve 7 is located between the connection of the second pipeline 11 and the secondary steam inlet pipeline 8 and between the secondary steam inlet pipeline 8 and the first pipeline 5.

[0024] Among them, the blind plate valve is a manual, electric or pneumatic / hydraulic gate valve specifically used to cut off the flow of gas or liquid medium.

[0025] It should be noted that when the first-effect falling-film evaporator 1 is under maintenance, the first blind plate valve 4 is closed and the second blind plate valve 6 is opened. Through the first blind plate valve 4, it is convenient to cut off the heat source of the first-effect falling-film evaporator and enable the low-pressure steam heat source to enter the second-effect falling-film evaporator 2 through the first pipeline 5, ensuring the independent operation of the second-effect falling-film evaporator 2; when the second-effect falling-film evaporator 2 is under maintenance, the first blind plate valve 4 is in the open state, the second blind plate valve 6 is in the closed state, the third blind plate valve 7 is closed, and the fourth blind plate valve 10 and the fifth blind plate valve 12 are opened, facilitating the entry of the secondary steam of a single effect into the condenser and the vacuum system for condensation during maintenance.

[0026] It is worth noting that the double-effect falling-film evaporator maintenance system performs separate-effect maintenance, that is, when the first-effect falling-film evaporator is under maintenance, the second-effect falling-film evaporator operates, and when the second-effect falling-film evaporator is under maintenance, the first-effect falling-film evaporator operates; the separation of the double-effect low-pressure heating steam is achieved through the first blind plate valve and the second blind plate valve, ensuring that the heat source supply of the first effect enters the second-effect falling-film evaporator when the first-effect falling-film evaporator is shut down for maintenance; the separation of the secondary steam is achieved through the third blind plate valve, the fourth blind plate valve and the fifth blind plate valve, ensuring the condensation of the secondary steam of the first effect when the second-effect falling-film evaporator is shut down for maintenance. The material is cut off through the blind plate valve, which takes a short time and reduces the workload of maintenance preparation; moreover, the double-effect falling-film evaporator can be maintained separately by effect, and a certain effect in the double effect can be kept operating during maintenance, ensuring the operation of a single effect while ensuring the upstream and downstream operation loads; the double-effect falling-film evaporator is continuously maintained during maintenance, and this technical solution effectively reduces the maintenance duration and reduces the maintenance risk.

[0027] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A double-effect falling film evaporator maintenance system, characterized in that: include: A first-effect falling film evaporator (1) and a second-effect falling film evaporator (2); A first blind plate valve (4) is connected to the low-pressure steam inlet pipeline (3) of the first-effect falling film evaporator (1); The low-pressure steam inlet pipeline (3) of the first-effect falling film evaporator (1) is connected to the secondary steam inlet pipeline (8) of the second-effect falling film evaporator (2) via a first pipeline (5), and the first pipeline (5) is connected to a second blind plate valve (6); A third blind plate valve (7) is connected to the secondary steam inlet pipeline (8) of the second-effect falling film evaporator (2).

2. The double-effect falling film evaporator maintenance system according to claim 1, characterized in that: A fourth blind plate valve (10) is connected to the secondary steam outlet pipeline (9) of the second-effect falling film evaporator (2), and the secondary steam outlet pipeline (9) is also connected to the condenser.

3. The double-effect falling film evaporator maintenance system according to claim 2, characterized in that: A second pipeline (11) is connected between the secondary steam outlet pipeline (9) of the second-effect falling film evaporator (2) and the secondary steam inlet pipeline (8) of the second-effect falling film evaporator (2), and a fifth blind plate valve (12) is connected to the second pipeline (11).

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