FC multi-effect evaporator shell side descaling cleaning device
By integrating a chemical tank, agitator, and steam heating into a closed-loop cleaning system, the problem of scaling on the shell side of the FC multi-effect evaporator was solved, achieving efficient and safe descaling operations and ensuring stable equipment operation and production continuity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUHAN HONGAO GREEN ENERGY ENG
- Filing Date
- 2025-05-22
- Publication Date
- 2026-06-12
AI Technical Summary
The shell-side scaling problem of existing FC multi-effect evaporators leads to reduced heat transfer efficiency, increased energy consumption, and difficulty in cleaning efficiently and safely.
A closed-loop cleaning system integrating a reagent tank, agitator, steam heating coil, reagent delivery filter, reagent circulation pump, and monitoring instruments was designed. The system removes scale buildup on the shell side by circulating cleaning agent, and utilizes agitation and steam heating functions to adapt to different materials, achieving automated control.
It significantly improves cleaning efficiency, shortens downtime, ensures safe operation of equipment and production continuity, and reduces operational complexity and safety risks.
Smart Images
Figure CN224345424U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of industrial wastewater treatment technology, and in particular to a descaling and cleaning device for the shell side of an FC multi-effect evaporator. Background Technology
[0002] In the field of industrial wastewater treatment, the treatment of high-salinity wastewater has always been a technical challenge. This type of wastewater contains high concentrations of inorganic salts (such as sodium chloride and sodium sulfate) and complex organic matter, and direct discharge would cause serious environmental pollution. Multi-effect evaporation technology, with its high energy efficiency and stable treatment capacity, has become one of the core processes for treating high-salinity wastewater. Among them, the FC (Falling Film Circulation) multi-effect evaporator is widely used due to its compact structure and efficient heat transfer performance. Its working principle is to use multiple effects connected in series, utilizing the secondary steam (exhaust steam) generated in the previous effect to provide a heat source for the next effect, gradually reducing energy consumption and achieving evaporation concentration and crystallization separation of wastewater.
[0003] However, in actual operation, FC multi-effect evaporators have a significant problem: shell-side scaling. Due to the complex composition of high-salt wastewater, droplets or tiny particles are easily entrained during evaporation (i.e., "foam-laden liquid"), causing solutes to enter the shell side of the next effect evaporator with the exhaust steam. The shell side, as a critical area for steam condensation and heat transfer, contains numerous heat exchange tubes, resulting in a complex structure and limited space. Solutes gradually deposit on the shell surface, forming a hard scale layer. This scaling not only significantly increases fouling thermal resistance and reduces heat transfer efficiency (the heat transfer coefficient can decrease by 20%–40%), but also leads to reduced evaporator capacity, increased steam consumption, and even localized overheating or corrosion, seriously threatening the safe operation of the equipment.
[0004] Currently, during the production and operation of FC multi-effect evaporation systems, descaling and cleaning of the evaporator is a necessary production maintenance operation. In daily production and maintenance, the tube side of the shell-and-tube evaporator is relatively easy to descale and clean by adding descaling agent to the circulation system. However, due to the structural design of the equipment, it is not convenient to descale and clean the shell side of the evaporator.
[0005] Therefore, the industry urgently needs a dedicated cleaning device for the shell side of evaporators, capable of efficient and controllable descaling operations with no downtime or short downtime, while also considering energy conservation, environmental protection, and operational safety. This solution addresses this need by proposing a device suitable for descaling and cleaning the shell side of FC multi-effect evaporators. Through integrated reagent preparation, dynamic circulation, and intelligent monitoring, it systematically solves the shell-side scaling problem, providing technical support for the stable operation of high-salinity wastewater treatment processes. Utility Model Content
[0006] This invention proposes a descaling and cleaning device for the shell side of an FC multi-effect evaporator, solving the problem in the prior art of how to achieve efficient and controllable descaling of the shell side of a multi-effect evaporator. The technical solution of this invention is implemented as follows:
[0007] A descaling and cleaning device for the shell side of an FC multi-effect evaporator includes:
[0008] The cleaning agent tank has a flange interface on the top and a stirrer inside the tank to evenly mix the cleaning agent; the inner wall of the tank is integrated with a spiral steam coil, which is connected to an external low-pressure steam source through the flange interface to heat the cleaning agent to the set temperature.
[0009] A pharmaceutical delivery filter, connected to the outlet of the pharmaceutical tank, is used to filter impurities in the cleaning agent;
[0010] A chemical circulation pump, connected to the filter outlet, is used to pump the cleaning agent to the shell side of the evaporator;
[0011] A closed-loop circulation pipeline connects the reagent outlet on the shell side of the evaporator with the inlet of the reagent tank to form a circulation loop;
[0012] The monitoring instrument group includes a chemical concentration monitoring instrument, a temperature monitoring instrument, and a flow monitoring instrument, which are used to regulate the concentration, temperature, and circulation flow of the cleaning agent in real time.
[0013] As a preferred technical solution, the external low-pressure steam source has a pressure range of 0.1 to 0.6 MPa.
[0014] As a preferred technical solution, the steam heating coil is a DN20 seamless steel pipe, the distance between the outer wall of the coil and the inner wall of the medicine tank is 150-200mm, the steam inlet is equipped with a shut-off valve, and the outlet is connected to a steam trap.
[0015] As a preferred technical solution, the agitator is an adjustable speed agitator with a double-layer blade structure. The blade diameter is 1 / 3 to 1 / 2 of the tank diameter. It is driven by a variable frequency motor and supports forward and reverse rotation.
[0016] As a preferred technical solution, the volume of the reagent tank is 1-3 m³. 3 The tank body adopts a flange connection, and the agitator is a paddle or anchor structure, which is vertically installed on the top or side wall of the tank body, with a rotation speed range of 30 to 60 r / min.
[0017] As a preferred technical solution, the outer wall of the medicine tank is covered with an insulation layer with a thickness of 30-50mm, and the material is rock wool or polyurethane foam.
[0018] As a preferred technical solution, the pharmaceutical delivery filter is a basket filter with a filtration accuracy of 60-80 mesh and the filter material is polytetrafluoroethylene (PTFE).
[0019] As a preferred technical solution, the reagent circulation pump is a centrifugal pump with a flow rate range of 1–3 m³ / h. 3 The pump has a flow rate of 15-20 m and a head of 15-20 m. A flow meter and a regulating valve are installed at the pump outlet.
[0020] As a preferred technical solution, in the closed-loop circulation pipeline, the reagent inlet of the evaporator shell side is located near the lower tube sheet, and the outlet is located near the upper tube sheet, forming a bottom-up flow path.
[0021] As a preferred technical solution, the reagent tank is equipped with a concentration detection instrument and a temperature detection instrument, and the internal temperature of the tank is controlled at 50-80℃.
[0022] Compared with existing technologies, this solution has the following advantages:
[0023] (1) High-efficiency cleaning capability: Through the design of circulating pump and closed loop, the cleaning agent is continuously circulated in the shell side, which prolongs the contact time between the agent and the scale, significantly improves the cleaning efficiency, and ensures that the scale is completely removed.
[0024] (2) Precise process control: Equipped with a real-time monitoring system for concentration (AI), temperature (TI), and flow rate (FI), it can accurately adjust cleaning parameters, avoid waste of chemicals or insufficient cleaning, and optimize cleaning effect.
[0025] (3) Adaptability and flexibility: The reagent tank integrates stirring and steam heating functions to support the cleaning needs of different shell materials (such as adjusting reagent concentration and temperature) and adapt to the removal of complex scale.
[0026] (4) Shorten downtime cycle, standardize and automate the cleaning process, and control the operation time to at least 8 hours (based on stable agent concentration). Compared with traditional manual cleaning methods, it greatly reduces equipment downtime and ensures production continuity.
[0027] (5) Convenient and safe operation. The integrated device design simplifies the operation process, reduces manual intervention, reduces operation complexity and safety risks, and is suitable for rapid deployment in industrial sites. Attached Figure Description
[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0029] Figure 1 This is a schematic diagram of the overall structure of a shell-side descaling and cleaning device for an FC multi-effect evaporator according to the present invention.
[0030] Explanation of reference numerals in the attached drawings: 1: Chemical tank; 2: Chemical delivery filter; 3: Chemical circulation pump; 4: Evaporator; 5: Chemical concentration monitoring instrument; 6: Chemical temperature monitoring instrument; 7: Circulation flow rate detection instrument. Detailed Implementation
[0031] The technical solution of this utility model will be clearly and completely described below with reference to its embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0032] Reference Figure 1 The purpose of this device is to provide a descaling and cleaning apparatus for the shell side of an FC multi-effect evaporator. This apparatus consists of the following components: a reagent tank 1 with stirring and steam coil heating; a reagent delivery filter 2; a reagent circulation pump 3; an FC evaporator 4; and a monitoring instrument group, including a reagent concentration monitoring instrument 5, a temperature monitoring instrument 6, and a circulation flow rate detection instrument 7, which are used to regulate the concentration, temperature, and circulation flow rate of the cleaning agent in real time.
[0033] In reagent tank 1, the cleaning agent (such as a weak acidic solution or chelating agent) is uniformly mixed using a stirrer. Simultaneously, low-pressure steam (0.1–0.6 MPa) is introduced through a steam coil to heat the solution to a set temperature (50–80°C) to enhance its chemical activity. The prepared cleaning agent is then filtered through a reagent delivery filter (60–80 mesh) to remove impurities. Finally, it is pumped by reagent circulation pump 3 at a speed of 1–3 m³ / h. 3 A flow rate of [flow rate] / h is pumped to the feed inlet (DN25 flange interface) at the bottom of the shell side of FC evaporator 4. The cleaning agent flows back to the cleaning agent tank 1 through the upper cleaning agent outlet of FC evaporator 4, and the entire descaling and cleaning device undergoes a circulating cleaning process. The cleaning agent flows from bottom to top through the evaporator shell side, removing scale adhering to the outer wall of the heat exchange tubes and the inner surface of the shell side through chemical dissolution or physical flushing. After cleaning is completed, the cleaning agent flows back to the cleaning agent tank 1 from the upper outlet of the shell side, forming a closed-loop circulation circuit.
[0034] Among them, the volume of the medicine tank 1 is 1-3m³. 3All connections to the outside are via flanges. A stirrer is installed in the middle of the reagent tank 1, with a speed of 30-60 r / min, which can be adjusted according to requirements. A steam heating coil is installed inside the reagent tank 1. The heating coil is made of DN20 seamless steel pipe, and the distance between the outer wall of the coil and the inner wall of the reagent tank 1 is 150-200 mm. The steam heating coil adopts a top-inlet and bottom-outlet design. The steam inlet uses a shut-off valve to control the steam flow, and the coil outlet is equipped with a drain valve to control the discharge of condensate. The steam heating coil is connected to the outside via flanges.
[0035] The external of the medicine tank 1 is equipped with heat insulation measures, with an insulation layer thickness of 30-50mm; it is also equipped with concentration detection instruments and temperature detection instruments, and the internal temperature of the tank is controlled at 50-80℃.
[0036] Among them, the reagent delivery filter 2 is a basket filter with a filtration accuracy of 60-80 mesh, using a flange connection, and the filter screen material is polytetrafluoroethylene (PTFE); the reagent circulation pump 3 is a centrifugal pump with a flow rate of 1-3 m³ / h. 3 The pump operates at a speed of [number] m / h, with a head of 15-20 m. The equipment uses flange connections at the pipe inlets, and a flow meter is installed at the pump outlet. The flow rate of the cleaning agent is adjusted via a valve at the pump outlet. For the FC evaporator, the cleaning agent adopts a bottom-in, top-out configuration. The inlet is located near the lower tube sheet of the heat exchanger, and the outlet is located near the upper tube sheet. The inlet and outlet pipe specifications are DN25, and the connection method is flange. During the operation of the descaling and cleaning device, the main monitoring parameters are the agent concentration (AI), temperature (TI), and cleaning agent flow rate (FI) in the tank. The agent concentration (AI) is selected based on the shell material of the FC evaporator.
[0037] Temperature (TI) is determined based on the operating temperature of the cleaning agent; flow rate (FI) is based on a residence time of the cleaning agent in the FC evaporator of not less than 30 minutes; the descaling cleaning operation time is considered complete when the concentration of the agent entering and leaving the FC evaporator fluctuates within 0.1% to 0.2%; the cleaning operation time is not less than 8 hours.
[0038] Real-time monitoring and parameter adjustment
[0039] 1. Concentration Monitoring (AI): Detects changes in the concentration of the cleaning agent. Cleaning is considered complete when the concentration fluctuation at the evaporator is ≤0.2%.
[0040] 2. Temperature Control (TI): Temperature is regulated by steam coils to maintain optimal reaction conditions;
[0041] 3. Flow control (FI): Ensure that the cleaning agent stays in the shell side for ≥30 minutes to guarantee the cleaning effect;
[0042] 4. Operating time: Total cleaning time ≥ 8 hours, automatically terminated based on concentration stability.
[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A descaling and cleaning device for the shell side of an FC multi-effect evaporator, characterized in that, include: The agent tank (1) has a flange interface on its top and a stirrer inside the tank body for uniformly mixing the cleaning agent; the inner wall of the tank is integrated with a spiral steam coil, which is connected to an evaporator (4) through the flange interface for heating the cleaning agent to a set temperature; A pharmaceutical delivery filter (2) is connected to the outlet of the pharmaceutical tank and is used to filter impurities in the cleaning agent; A chemical circulation pump (3) is connected to the filter outlet and is used to pump the cleaning agent to the shell side of the evaporator. A closed-loop circulation pipeline connects the reagent outlet on the shell side of the evaporator with the inlet of the reagent tank to form a circulation loop; The monitoring instrument group includes a chemical concentration monitoring instrument, a temperature monitoring instrument, and a flow monitoring instrument, which are used to regulate the concentration, temperature, and circulation flow of the cleaning agent in real time.
2. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The external low-pressure steam source has a pressure range of 0.1~0.6 MPa.
3. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The medicine tank (1) is equipped with a steam heating coil inside. The steam heating coil is a DN20 seamless steel pipe. The distance between the outer wall of the coil and the inner wall of the medicine tank is 150~200 mm. The steam inlet is equipped with a shut-off valve, and the outlet is connected to a drain valve.
4. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The stirrer is an adjustable speed stirrer with a double-layer blade structure. The blade diameter is 1 / 3 to 1 / 2 of the tank diameter. It is driven by a variable frequency motor and supports forward and reverse rotation.
5. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The volume of the reagent tank is 1~3 m³, the tank body adopts a flange connection, and the agitator is a paddle or anchor structure, which is vertically installed on the top or side wall of the tank body, with a rotation speed range of 30~60 r / min.
6. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The outer wall of the medicine container (1) is covered with a heat insulation layer with a thickness of 30~50 mm, and the material is rock wool or polyurethane foam.
7. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The drug delivery filter (2) is a basket filter with a filtration accuracy of 60-80 mesh and the filter material is polytetrafluoroethylene (PTFE).
8. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The pharmaceutical circulation pump (3) is a centrifugal pump with a flow rate range of 1~3 m³ / h and a head of 15~20 m. A flow meter and a regulating valve are installed at the pump outlet.
9. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, In the closed-loop circulation pipeline, the agent inlet of the shell side of the evaporator (4) is located near the lower tube sheet, and the outlet is located near the upper tube sheet, forming a flow path from bottom to top.
10. The FC multi-effect evaporator shell-side descaling and cleaning device as described in claim 1, characterized in that, The medicine container is equipped with a concentration detection instrument and a temperature detection instrument, and the temperature inside the container is controlled at 50~80℃.