Nonmetal film evaporator
By using heat exchange diaphragm and hard support strip prepared by non-metallic films, combined with the gas-liquid separation chamber and tube box structure, the problem of metal evaporators not resistant to corrosion and prone to scale in wastewater treatment is solved, and efficient and low-cost wastewater treatment is achieved.
Patent Information
- Application Number
- CN202421406501.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-19
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-06-19
AI Technical Summary
In the wastewater treatment, existing metal evaporators have problems such as incorruptible corrosion, easy scaling, and difficult to clean, resulting in increased complexity and operating costs of the treatment system.
A non-metallic film is used to prepare a heat exchange film sheet, and a heat exchange film group is formed by a hard support strip, combining the gas-liquid separation chamber and the tube box structure to achieve spaced heat exchange.
It improves heat transfer efficiency and reduces manufacturing costs. The film is resistant to acid and alkali corrosion, has a smooth surface, is easy to clean, and is not easy to scale. It is suitable for treating high COD, high salt, strong acidic and strong alkaline wastewater.
Smart Images
Figure CN222989834U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a non-metallic thin film evaporator. Background Art
[0002] At present, evaporators widely used in the wastewater treatment industry (such as single-effect evaporators, multi-effect evaporators, MVR evaporators, etc.) basically use metal materials as the partition heat transfer elements. These metal heat exchange materials often use 316L stainless steel, 2205 or 2507 duplex steel, TA2, TA10, or even more expensive precious metals such as nickel and zirconium for manufacturing, resulting in a very high one-time investment cost for evaporation equipment. In addition, when applying such metal evaporators to the water treatment industry, problems such as equipment corrosion resistance, scale formation, and difficult scale cleaning often occur. In practice, it is necessary to add pretreatment processes (such as adding chemicals to remove hardness, reducing COD, removing fluorine, adjusting the PH value, etc.) before evaporation, which also increases the complexity and operating cost of the treatment system. Summary of the Utility Model
[0003] The purpose of the utility model is to provide a falling film evaporator with a heat transfer element that is not prone to scale formation and corrosion.
[0004] The technical solution of the utility model is: a non-metallic thin film evaporator, provided with a gas-liquid separation chamber, in which a cloth pipe and one or more heat exchange elements located below the cloth pipe are provided. The heat exchange elements adopt a heat exchange film group, and the heat exchange film group is composed of one or more heat exchange film sheets arranged vertically. The multiple vertically arranged heat exchange film sheets are parallel to each other. The heat exchange film sheet is composed of two side heat exchange films, and there are several mutually parallel fusion welds (continuous fusion welds) between the two side heat exchange films. The two films on both sides between adjacent fusion welds can be separated from each other to form a heat exchange medium channel in the heat exchange film sheet. The heat exchange film adopts a non-metallic material.
[0005] Preferably, the heat exchange film is a flexible polymer film.
[0006] Further, a rigid support bar is fixed to the top of the heat exchange film sheet.
[0007] A rigid support bar is also fixed to the bottom of the heat exchange film sheet.
[0008] Preferably, the support bar adopts a non-metallic material, such as a rigid polymer material.
[0009] Generally, the support bar is horizontally arranged.
[0010] Preferably, the support bar is a flat bar, and the vertical dimension of its cross-section is greater than the horizontal dimension (the direction perpendicular to the vertical direction in the cross-section).
[0011] Further, two tube headers are provided at the left and right ends (also referred to as the left and right sides, and the left and right directions are the horizontal extension directions of the heat exchange diaphragms) of each heat exchange diaphragm. The inner cavities of the two tube headers are respectively communicated with the corresponding ends of the heat exchange medium channels on each heat exchange diaphragm.
[0012] Further, the inner side (heat exchange diaphragm side) wall of the tube header adopts a tube sheet (or a tube sheet structure). The tube sheet is provided with hole grooves corresponding to the heat exchange diaphragms. The two ends of the heat exchange diaphragm are bonded to the corresponding hole grooves (groove walls). The heat exchange medium channels in the heat exchange diaphragm are communicated with the inner cavity of the corresponding tube header through the hole grooves on the tube sheet.
[0013] The hole grooves can be vertical long holes, communicating with multiple (including all or part) heat exchange medium channels (corresponding ports of the heat exchange medium channels) on the corresponding heat exchange diaphragm.
[0014] The hole grooves can be round holes or oval holes, communicating with one heat exchange medium channel (corresponding port of the heat exchange medium channel) on the corresponding heat exchange diaphragm.
[0015] Preferably, there are no fusion welds for separating the heat exchange medium channels in the edge areas at both ends of the heat exchange diaphragm to facilitate the bonding of the heat exchange diaphragm to the corresponding hole grooves (groove walls) at the ends. However, under the condition of not interfering with the bonding to the hole grooves, the fusion welds should be long enough or as long as possible to facilitate the separation between the heat exchange medium channels.
[0016] Further, a heating steam inlet is provided on one of the two tube headers (for example, the left tube header), and a non-condensable gas discharge port and a condensate discharge port are provided on the other tube header (for example, the right tube header).
[0017] Preferably, the heating steam inlet is arranged at the top of the corresponding tube header.
[0018] The number of heating steam inlets is usually 1.
[0019] Preferably, the condensate discharge port is arranged at the bottom of the corresponding tube header
[0020] The number of condensate discharge ports is usually 1.
[0021] Preferably, the non-condensable gas discharge port is arranged on the outer side wall of the corresponding tube header.
[0022] The number of non-condensable gas discharge ports is usually multiple.
[0023] Preferably, the fusion welds for separating the heat exchange medium channels are inclined nearly horizontally (the included angle with the horizontal plane is less than the included angle with the vertical plane).
[0024] The included angle between the fusion welds for separating the heat exchange medium channels and the horizontal plane is 3 to 10°.
[0025] Furthermore, a plurality of liquid distribution ports are provided on the feed pipe in the gas-liquid separation chamber, and the liquid distribution ports are distributed above the heat exchange module.
[0026] Furthermore, the gas-liquid separation chamber adopts an integrated tank body (or called a shell).
[0027] Furthermore, a demister / demisting device is provided in the gas-liquid separation chamber, and the demister / demisting device is located above the feed pipe.
[0028] Furthermore, a steam outlet (secondary steam outlet) is provided at the top of the tank body of the gas-liquid separation chamber.
[0029] Furthermore, a discharge port is provided at the bottom of the tank body of the gas-liquid separation chamber.
[0030] The beneficial effects of the present utility model are as follows: Since a heat transfer / heat exchange is carried out by using a heat exchange membrane sheet made of a non-metal (polymer material), and in practice, the thickness of the membrane sheet can be 20-60 μm, the heat transfer temperature difference is small, the heat transfer coefficient is high, the structure is compact, and the evaporation intensity is large; since the thin film is soft and the surface is very smooth, the scale layer precipitated in the material is not easy to adhere to the surface of the membrane sheet, and the scale blocks are extremely easy to agglomerate and fall off. Compared with the existing metal plates, such thin films are resistant to acid and alkali corrosion, have good hydrophobicity, smooth surfaces, are easy to clean, and are not easy to scale; since a plurality of heat exchange membrane sheets are combined into a heat exchange membrane group, the two-side tube boxes and the support bars of the membrane sheets in the heat exchange membrane group are made of hard materials, which facilitates installation and maintenance / replacement, and the heat exchange surface area per unit volume is large, and the manufacturing cost is extremely low; since a nearly horizontal (slightly inclined) channel is adopted in the heat exchange membrane sheet, it is beneficial to the flow of condensed water and non-condensable gases; since heated steam and condensed water flow in the nearly horizontal channel of the heat exchange membrane sheet, and waste water flowing from top to bottom flows outside both sides of the membrane sheet, an intermittent heat exchange is realized, and since after the steam is introduced, the thin films on both sides of the channel in the membrane sheet bulge outwards and form a wave shape vertically, the waste water flowing up and down is continuously disturbed, forming a very good turbulent effect, greatly improving the convective heat transfer film coefficient of the waste water on the wall surface.
[0031] The present utility model effectively avoids the disadvantages of the traditional falling film evaporator made of metal materials, such as easy scaling on the material side, difficult cleaning of the scale, and high manufacturing cost. It can be widely applied to the waste water evaporation treatment processes in industries such as printing and dyeing, leather, medicine, and fine chemical industry. It is especially suitable for concentrating and treating various comprehensive waste waters with high COD, high salt content, strong acidity, strong alkalinity, and high hardness. Moreover, the larger the water volume, the more obvious the advantages of the investment cost and the operation cost. Brief Description of the Drawings
[0032] Figure 1 is a structural schematic diagram of the present utility model;
[0033] Figure 2 is a schematic diagram of a single heat exchange membrane group involved in the present utility model;
[0034] Figure 3 is Figure 2 the schematic view of A - A involved;
[0035] Figure 4 is Figure 2 the schematic view of B - B involved;
[0036] Figure 5 is Figure 2 the schematic view of C - C involved;
[0037] Figure 6 is Figure 5 the partial enlarged view of I involved.
[0038] The markings in the figure are as follows: 1, left tube sheet; 2, right tube sheet; 3, heating steam inlet; 4, non - condensable gas discharge port; 5, condensate discharge port; 6, heat exchange membrane; 7, support bar; 8, fusion weld; 9, feed pipe; 10, liquid distribution port; 11, demister; 12, steam outlet; 13, discharge port; 14, vapor - liquid separation chamber; 15, heat exchange membrane group; 16, tube sheet. Specific embodiments
[0039] See Figure 1 , the vapor - liquid separation chamber 14 as a whole is composed of a sealed tank body made of 1 metal or non - metal (such as, fiberglass, etc.). There is a steam outlet 12 for secondary steam opened at the top of the tank body, a discharge port 13 opened at the bottom, and an interface (or interface pipe) for a heater inlet 3, an interface for a feed pipe (cloth - feeding pipe) 9, an interface for a non - condensable gas discharge port 4, and an interface for a condensate discharge port 5 opened on the side wall.
[0040] See Figure 2 , Figure 3 and Figure 4, each heat exchange membrane group 15 is composed of a left header 1, a right header 2, and a plurality of heat exchange membranes 6 located in the middle. The heat exchange membranes are formed by folding a single piece in half and bonding them together, or by bonding two identical non-metallic (e.g., polymer) heat exchange films to each other. Through the hot melt weld seam 8 between the two side heat exchange films, they are bonded into one body. Vertically, steam or other fluids can be introduced between the two side films located between adjacent weld seams. After the fluid is introduced, under the action of the fluid pressure, both side films bulge outwards, forming an elliptical-like gap in the middle, which is used as a heat exchange (heat release) medium channel (or heat exchange channel). A rigid support bar 7 is provided at the top of the heat exchange membrane to form a rigid support. When the film is folded in half, the support bar can be placed at the folding part. When folding, the support bar is wrapped between the two side films of the fold, and the support bar is bonded to the two side films by hot melt and / or a weld seam is formed close to the lower part of the support bar. The films wrapped on both sides of the support bar are tightened, fixing the support bar at the top of the heat exchange membrane; when preparing the heat exchange membrane with two films, the top of one side film can wrap the support bar and bond / tighten and weld the support bar to the wrapped film, and then the top of the other side film is wrapped and bonded / welded to the film that has been wrapped outside the support bar.
[0041] According to actual needs, a rigid support bar can be provided at the bottom of the heat exchange membrane in the same or similar manner.
[0042] A number of heat exchange membranes are arranged parallel to each other. The two ends of the heat exchange membranes are respectively connected to the tube sheet 16 or the header in the corresponding section by melting or bonding, forming a heat exchange membrane group 15 containing a number of heat exchange membranes. The two ends of the support bar are fixed (e.g., welded) to the header at the corresponding end. The support bar, tube sheet, and header can all be made of suitable non-metallic materials such as PTFE, and metal materials can also be used when necessary. A number of tube holes corresponding to the heat exchange channels on each heat exchange membrane are provided on the tube sheet, and the heat exchange channels in the heat exchange membrane are connected to the corresponding tube holes. The tube sheet can be used as the inner wall of the header, or the inner wall of the header can be set as the tube sheet.
[0043] A heating steam inlet 3 is provided on the left header 1, a plurality of non-condensable gas discharge ports 4 are provided on the right header 2, and a condensate discharge port 5 is provided at the bottom of the right header 2. Heating steam is introduced into the heating steam inlet. The heating steam flows from the left header through the heat exchange channels in each heat exchange membrane to the right header. The condensed condensate flows into the bottom of the right header 2 and flows out from the condensate discharge port 5. The non-condensable gas mixed in the heating steam is continuously discharged from the non-condensable gas discharge port 4.
[0044] See Figure 5 and Figure 6, a large number of columns of oval holes (or tube holes) are respectively formed in each tube sheet 16, and each heat exchange diaphragm 6 is hot-melted or bonded around the holes in the corresponding column. When heating steam is introduced into each heat exchange diaphragm 6, an oval heat exchange steam channel is formed due to the internal and external pressure difference. From left to right, each steam heat exchange channel formed by heat melting treatment forms a certain angle θ (for example, θ = 3 - 10°) with the horizontal direction obliquely downward, which is conducive to the faster discharge of condensate when the steam condenses.
[0045] The non-metallic film used to prepare the heat exchange diaphragm can adopt polymer materials / plastic films. For example, polycarbonate film (PC film), polyetheretherketone film (PEEK film), polyphenylsulfone film (PPSU film), polysulfone film (PSU film), polytetrafluoroethylene film (PTFE film), etc., to form a flexible heat exchange diaphragm, and the bonding and formation of the weld seam (continuous weld seam) for separating the heat exchange channel can be carried out through simple methods such as hot melting or bonding. According to known data, the thermal resistance of these polymer material films with a thickness of 20 - 60μm is equivalent to that of 304 / 316L stainless steel plates with a wall thickness of 0.8 - 1.5mm at the same temperature, and the polymer material films with this thickness have a certain toughness and strength and can be used as the films for preparing the heat exchange diaphragm. After the heat exchange diaphragm is prepared into a module, it can be conveniently assembled into the corresponding evaporation device.
[0046] According to the prior art, a number of cloth outlets 10 located above the heat exchange module can be provided on the cloth pipe in the gas-liquid separation chamber, and a demister 11 is provided at an appropriate position above the cloth pipe / cloth outlet.
[0047] The utility model has the following innovative features:
[0048] A flexible polymer film is used to prepare the heat exchange diaphragm, and the flexible heat exchange diaphragm is supported by a rigid support bar and installed on the rigid tube boxes on both sides to form a heat exchange film group with a rigid skeleton, which is convenient for use;
[0049] The heat exchange film group adopts a horizontal tube type, which can more effectively improve the convective heat transfer film coefficient on the material side and is also conducive to the condensate drainage on the steam side, thereby improving the total heat transfer coefficient.
[0050] The cylinder / tank of the equipment is made of a non-metallic material, such as fiberglass, and has good corrosion resistance.
[0051] All the preferred and optional technical means disclosed in the utility model can be arbitrarily combined to form several different specific embodiments, except when specifically stated and when one preferred or optional technical means is a further limitation of another technical means.
Claims
1. A non-metallic thin film evaporator, provided with a gas-liquid separation chamber, wherein a distribution pipe and one or more heat exchange elements located below the distribution pipe are provided in the gas-liquid separation chamber, characterized in that The heat exchange element adopts a heat exchange membrane group, which is composed of one or more heat exchange membranes arranged on the vertical surface. The heat exchange membranes arranged on the multiple vertical surfaces are parallel to each other. The heat exchange membrane is composed of heat exchange films on both sides. A number of parallel fusion welds are arranged between the heat exchange films on both sides. The films on both sides located between adjacent fusion welds can be separated from each other to form a heat exchange medium channel in the heat exchange membrane. The heat exchange film is made of non-metallic material.
2. The non-metallic thin film evaporator according to claim 1, characterized in that The heat exchange film is a flexible polymer film.
3. The non-metallic thin film evaporator according to claim 1, characterized in that The angle between the fusion weld used to separate the heat exchange medium channel and the horizontal plane is 3 to 10 degrees.
4. The non-metallic thin film evaporator according to claim 1, characterized in that A hard support bar is fixed on the top of the heat exchange membrane.
5. The non-metallic thin film evaporator according to any one of claims 1 to 4, characterized in that The heat exchange membrane group is provided with two pipe boxes respectively located at the left and right ends of each heat exchange membrane, and the inner cavities of the two pipe boxes are respectively connected with the corresponding ends of each heat exchange medium channel on each heat exchange membrane.
6. The non-metallic thin film evaporator according to claim 5, characterized in that The inner wall of the tube box adopts a tube sheet, which is provided with holes and grooves corresponding to the heat exchange diaphragm. Both ends of the heat exchange diaphragm are bonded to the corresponding holes and grooves. The heat exchange medium channels in the heat exchange diaphragm are connected to the inner cavity of the corresponding tube box through the holes and grooves on the tube sheet.
7. The non-metallic thin film evaporator according to claim 5, characterized in that One of the two pipe boxes is provided with a heating steam inlet, and the other pipe box is provided with a non-condensable gas discharge port and a condensate discharge port.
8. The non-metallic thin film evaporator according to claim 7, characterized in that The heating steam inlet is arranged at the top of the corresponding pipe box.
9. The non-metallic thin film evaporator according to claim 7, characterized in that The condensate discharge port is arranged at the bottom of the corresponding pipe box.
10. The non-metallic thin film evaporator according to claim 7, characterized in that The non-condensable gas discharge port is arranged on the outer box wall of the corresponding pipe box.