A combined heat exchanger for flue gas whitening
By using a combination of heat exchangers to raise the temperature and eliminate white plumes, the problem of white plumes in flue gas has been solved, achieving efficient energy utilization and heat recovery, eliminating plumes and saving equipment space.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING YIRE ZONGLIAN ENVIRONMENTAL PROTECTION TECH LIYANG CO LTD
- Filing Date
- 2025-09-08
- Publication Date
- 2026-07-31
AI Technical Summary
The white plume phenomenon caused by industrial flue gas emissions affects the corporate image and may have an impact on the environment. Existing technologies are unable to effectively eliminate and recover the heat from the flue gas.
A combined heat exchanger is adopted, including a plate heat exchanger, a flue gas condenser, and a steam heater. Multiple methods are used to raise the temperature, eliminate white spots, and recover the heat of the flue gas. The combination of plate heat exchanger cooling, flue gas condenser dewatering, bottom air duct drainage, and steam heater heating is utilized.
It effectively eliminates white plumes from flue gas, improves energy efficiency, reduces equipment footprint, and enables the recovery of flue gas heat.
Smart Images
Figure CN224580783U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of heat exchanger technology, specifically relating to a combined heat exchanger for flue gas whitening. Background Technology
[0002] In industrial production processes, many enterprises emit large amounts of flue gas. This flue gas typically contains water vapor, which, due to the low ambient temperature, rapidly cools and condenses upon discharge, forming a white plume, the so-called "flue gas tail." This phenomenon not only affects the company's image but may also have a certain impact on the environment. Therefore, flue gas whitening technology has emerged. This utility model is a novel combined heat exchanger that, through the coordinated operation of an air-to-air plate heat exchanger, a flue gas cooler, and a steam heater, can effectively achieve flue gas whitening while recovering heat from the flue gas, thus improving energy utilization efficiency. Utility Model Content
[0003] The purpose of this invention is to provide a combined heat exchanger for flue gas whitening, so as to solve the problems mentioned in the background art.
[0004] To achieve the above objectives, this utility model provides the following technical solution: a combined heat exchanger for flue gas whitening, comprising a plate heat exchanger, a flue gas condenser, a bottom air duct, and a steam heater. One side air duct of the plate heat exchanger is connected to the flue gas condenser, and the flue gas condenser is connected to the other side air duct of the plate heat exchanger through the bottom air duct. The other side air duct of the plate heat exchanger is also connected to the steam heater.
[0005] Preferably, the plate heat exchanger is a gas-to-gas plate heat exchanger, and the heat exchange plates of the plate heat exchanger are corrugated plates.
[0006] Preferably, the flue gas condenser is configured as a finned tube heat exchanger.
[0007] Preferably, a drain outlet is provided on the bottom air duct.
[0008] Preferably, the steam heater is a finned tube heat exchanger.
[0009] Preferably, the plate heat exchanger, flue gas condenser, bottom air duct and steam heater are all connected by flanges.
[0010] The technical effects and advantages of this utility model are as follows: This combined heat exchanger for flue gas whitening uses a plate heat exchanger to heat the exhaust flue gas and a steam heater to heat it, combining multiple methods to heat and eliminate whitening, which not only ensures the reliability of whitening elimination but also saves energy; it can recover heat from the flue gas while eliminating whitening; and the integration of multiple methods into one device effectively reduces the footprint. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model.
[0012] In the diagram: 1. Plate heat exchanger; 2. Flue gas condenser; 3. Bottom air duct; 4. Steam heater. Detailed Implementation
[0013] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding of this utility model, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0014] This utility model provides, for example Figure 1 The present invention discloses a combined heat exchanger for flue gas whitening, comprising four components: a plate heat exchanger 1, a flue gas condenser 2, a bottom air duct 3, and a steam heater 4. The components are connected by flue flanges. One side air duct of the plate heat exchanger 1 is connected to the flue gas condenser 2, and the flue gas condenser 2 is connected to the other side air duct of the plate heat exchanger 1 through the bottom air duct 3. The other side air duct of the plate heat exchanger 1 is also connected to the steam heater 4. The specific workflow is as follows: Hot flue gas enters plate heat exchanger 1 through the hot flue gas inlet to exchange heat with the cooled flue gas, thus lowering the temperature of the hot flue gas; the cooled flue gas passes through flue gas condenser 2, where it exchanges heat with cold water to further cool the hot flue gas, causing the water vapor in the flue gas to condense and be discharged, thereby reducing the water content in the flue gas, while simultaneously heating the cold water for energy recovery; the flue gas after passing through flue gas condenser 2 then enters bottom duct 3. The main function of bottom duct 3 is to connect flue gas condenser 2 and plate heat exchanger 1. This duct is not insulated and relies on natural heat. The convection further cools the flue gas, thereby further removing the moisture content. The bottom duct 3 has a drain port at its lowest end to promptly discharge the condensate generated by the flue gas condenser 2 and the bottom duct 3. The moisture content of the flue gas passing through the bottom duct 3 has been reduced. It exchanges heat with the original high-temperature flue gas through the gas-to-gas plate heat exchanger 1, increasing the temperature of the flue gas and thus deviating from the saturation point. The flue gas passing through the plate heat exchanger 1 then enters the steam heater 4, further increasing its temperature. The steam heater 4 serves as the final guarantee for whitening and does not need to be turned on under normal circumstances.
[0015] In this scheme, the hot flue gas is cooled by plate heat exchanger 1; the moisture content in the hot flue gas is reduced by flue gas condenser 2 and bottom air duct 3, and a drain port is opened on the bottom air duct to discharge condensate in time. Flue gas condenser 2 can also recover heat; then the flue gas is heated by plate heat exchanger 1 to make it deviate from the saturated dew point; finally, the steam heater 4 is used as a guarantee for eliminating white spots.
[0016] In this design, plate heat exchanger 1 is a fully welded high-efficiency corrugated plate heat exchanger, consisting of a hot-side inlet, hot-side outlet, cold-side inlet, cold-side outlet, and internal corrugated plates, all four ports being flanges. Flue gas condenser 2 is a high-frequency welded finned tube heat exchanger, consisting of high-frequency welded finned tubes, a shell, a flue gas inlet, a flue gas outlet, a cooling water inlet, and a hot water outlet, all with flanges for both flue gas and water inlets / outlets. Bottom duct 3 consists of a flue gas inlet, a flue gas outlet, a shell duct, and a bottom drain. Steam heater 4 is a finned tube heat exchanger consisting of high-frequency welded finned tubes, a shell, a steam inlet, and a condensate outlet. All components are connected by flanges. The shells of the gas-to-gas plate heat exchanger 1, flue gas condenser 2, and steam heater 4 are insulated; however, the bottom duct 3 is not insulated.
[0017] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A combined heat exchanger for flue gas whitening, characterized in that: It includes a plate heat exchanger (1), a flue gas condenser (2), a bottom air duct (3) and a steam heater (4). One side air duct of the plate heat exchanger (1) is connected to the flue gas condenser (2), and the flue gas condenser (2) is connected to the other side air duct of the plate heat exchanger (1) through the bottom air duct (3). The other side air duct of the plate heat exchanger (1) is also connected to the steam heater (4).
2. A combined heat exchanger for flue gas whitening according to claim 1, characterized in that: The plate heat exchanger (1) is a gas-to-gas plate heat exchanger, and the heat exchange plates of the plate heat exchanger (1) are corrugated plates.
3. A combined heat exchanger for flue gas whitening according to claim 1, characterized in that: The flue gas condenser (2) is configured as a finned tube heat exchanger.
4. A combined heat exchanger for flue gas whitening according to claim 1, characterized in that: A drain outlet is provided on the bottom air duct (3).
5. A combined heat exchanger for flue gas whitening according to claim 1, characterized in that: The steam heater (4) is a finned tube heat exchanger.
6. A combined heat exchanger for flue gas whitening according to claim 1, characterized in that: The plate heat exchanger (1), flue gas condenser (2), bottom air duct (3) and steam heater (4) are all connected by flanges.