Landfill leachate resource treatment equipment

Abstract

The application relates to the technical field of garbage treatment equipment, and discloses a landfill leachate resource treatment equipment, which comprises an evaporator, the evaporator is sequentially formed with a liquid distribution cavity, an evaporation cavity and a discharge cavity from top to bottom, a large number of heat exchange pipes are arranged in the evaporation cavity, the side wall of the evaporation cavity is communicated with a compression pump, the liquid distribution cavity is provided with a uniform distribution piece and a flow guide plate from bottom to top, a plurality of uniform distribution openings corresponding to the heat exchange pipes are arranged on the uniform distribution piece, a flow guide rod is arranged in the heat exchange pipe, the flow guide rod penetrates through the uniform distribution piece and the flow guide plate, the flow guide plate guides the leachate to the flow guide rod, a film supplementing head is arranged at the bottom of the flow guide rod, and the film supplementing head guides the leachate to the inner wall of the heat exchange pipe and supplements the liquid film flow. The landfill leachate resource treatment equipment is provided with the film supplementing head in the lower section of the heat exchange pipe of the evaporator, a gradient liquid film new mechanism of 'thin liquid film efficient evaporation in the upper section and fixed-point film supplementing anti-drying in the lower section' is constructed, and the efficiency and safety of the evaporation process are considered.

Description

Technical Field

[0001] This application relates to the field of waste treatment equipment technology, and in particular to a waste landfill leachate resource recovery treatment device. Background Technology

[0002] MVR evaporators are currently the core equipment in the field of landfill leachate treatment, especially in the resource utilization and zero-discharge process of concentrated liquid. Through evaporation, they can further reduce the volume of old leachate or filtered concentrated liquid by more than 90%, and the distilled water produced can be reused or discharged in compliance with standards. The remaining small amount of high-concentration mother liquor or salt mud can be solidified and landfilled, which can greatly reduce the later operating costs.

[0003] Falling film evaporators are a common structure in MVR evaporators. When evaporating the leachate, secondary steam flows along the outer wall of the heat exchange tubes. The secondary steam liquefies and releases heat to heat the heat exchange tubes, while the leachate flows along the inner wall of the heat exchange tubes in the form of a film, absorbing the heat from the heat exchange tubes. Generally, the thinner the liquid film, the shorter the distance heat travels from the tube wall to the liquid surface, the lower the thermal resistance, the higher the evaporation efficiency, and the more energy-efficient the evaporator. At the same time, a thin liquid film is usually accompanied by a higher flow velocity and a higher degree of turbulence, making it less likely for crystals to adhere to the tube wall and less prone to scaling. However, when the liquid film becomes too thin, it may dry out. Once the liquid film breaks, the tube wall is directly exposed to the steam (or only has a very thin oil / salt film), and the tube wall temperature will soar instantly. The high temperature will char (carbonize) the remaining organic matter or crystallize the salt instantly into hard scale. This not only reduces heat transfer but also damages the equipment. Therefore, to avoid the liquid film at the lower end of the heat exchange tube drying out, the thickness of the liquid film at the upper end is increased, that is, the liquid inlet flow is increased to increase the overall thickness of the liquid film, sacrificing evaporation efficiency.

[0004] Secondly, as the number of cycles increases, the leachate becomes more concentrated, its viscosity increases, its surface tension decreases, and its flow velocity along the pipe wall decreases. The concentrated liquid is more likely to precipitate crystals, which can easily cause flow interruption. Therefore, in the later stage of evaporation, the evaporation strategy needs to be adjusted to "maintain flow rate and reduce load". Since the evaporation efficiency is sacrificed, the circulation ratio will increase and energy consumption will increase. Summary of the Invention

[0005] This application proposes a landfill leachate resource recovery treatment device, which incorporates a "film replenishment head" in the lower section of the heat exchange tubes of the evaporator to construct a new gradient liquid film mechanism of "high-efficiency evaporation of thin liquid film in the upper section and fixed-point film replenishment in the lower section to prevent drying out", thus taking into account both the "efficiency and safety" of the evaporation process.

[0006] To achieve the above objectives, this application adopts the following technical solution: a landfill leachate resource utilization treatment device, comprising an evaporator, a separator, a circulation pump, and a compression pump. Steam and residual liquid in the evaporator flow into the separator. Liquid in the separator is directly discharged or returned to the evaporator via the circulation pump. Secondary steam in the separator is returned to the evaporator via the compression pump. The evaporator, from top to bottom, forms a liquid distribution chamber, an evaporation chamber, and a discharge chamber. The evaporation chamber is equipped with densely packed heat exchange tubes. The sidewall of the evaporation chamber is connected to the compression pump. The liquid distribution chamber is equipped with a uniform distribution element and a guide plate from bottom to top. The uniform distribution element has multiple uniform distribution ports corresponding to the heat exchange tubes. A guide rod is sleeved inside the heat exchange tube, passing through the uniform distribution element and the guide plate. The guide plate guides the leachate to the guide rod. A film replenishment head is provided at the bottom of the guide rod, guiding the leachate to the inner wall of the heat exchange tube and replenishing the liquid film flow.

[0007] Furthermore, the membrane filling head is located at the bottom 1 / 2 to 1 / 3 of the heat exchange tube.

[0008] Furthermore, the membrane head includes an overflow groove, and an overflow ring is provided on the outer wall of the overflow groove. The minimum distance between the overflow ring and the inner wall of the heat exchange tube is 0.15-0.25mm. The overflow ring is made of elastic material and is inclined outward from top to bottom. The bottom of the overflow ring has an annular hollow at the connection with the overflow groove, so that the overflow ring can be folded inward.

[0009] Furthermore, the membrane head also includes a liquid collection cylinder fixedly connected to the guide rod. The liquid flows along the outer wall of the guide rod and eventually flows into the liquid collection cylinder, reducing the liquid flow rate and facilitating cleaning while reducing splashing. The liquid collection cylinder is connected to the overflow tank through an overflow pipe.

[0010] Furthermore, a flow guide shroud is provided at the position of the flow guide rod corresponding to the flow guide plate, and the bottom of the flow guide shroud is an elastic ring.

[0011] Furthermore, the uniform distribution component is a cylindrical body with a bottom, and the inner wall is provided with flanges corresponding to the guide plate and the flow divider plate respectively. After the guide plate and the flow divider plate are installed on the flanges, they form three closed cavities. The lower closed cavity is connected to the heat exchange tube, and the middle closed cavity is connected to the guide rod through the guide shroud.

[0012] Furthermore, the diversion plate is provided with a partition plate, which forms two sets of slots. Each slot in the same set is connected by a pipe. One set of slots is connected to the middle closed cavity through a perforated slot, and the other set of slots is connected to the lower closed cavity through a connecting pipe. The upper end of the liquid distribution chamber is provided with a liquid inlet head corresponding to the two sets of slots. The flow rate of the liquid inlet head is controlled by a solenoid valve.

[0013] Furthermore, in order to make the liquid flowing into the heat exchange tube more uniform, the uniform distribution component is provided with an overflow hood that is offset from the connecting pipe at the position corresponding to the heat exchange tube.

[0014] The beneficial effects of this invention are as follows:

[0015] This application provides a landfill leachate resource recovery treatment device. On the one hand, a more aggressive evaporation strategy can be adopted at the upper and middle ends of the heat exchange tubes to form a thinner liquid film on the inner wall of the heat exchange tubes, thereby improving evaporation efficiency. A film is added at the lower end of the heat exchange tubes to ensure the thickness of the liquid film and prevent it from drying out. On the other hand, the flow velocity of the liquid film is more controllable. The thin film corresponds to a small amount of low-speed steam flowing at the upper end, reducing the probability of the film being blown off by the steam. The thick film corresponds to the high-speed steam flowing at the lower end, ensuring the flow velocity of the thick film, which can better flush the lower end of the heat exchange tubes and reduce the probability of scaling on the heat exchange tubes.

[0016] Secondly, the heat exchange tube is divided into two sections with the membrane head as the boundary. When dealing with concentrated liquid that has been circulated multiple times, the heat exchange tube of a single section is relatively short and has a limited evaporation capacity, which can ensure the liquid film flow rate without reducing the load and ensuring the evaporation efficiency. On the outside of the heat exchange tube, it is still a whole with a longer length, which can fully contact the secondary steam and absorb the energy of the steam. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort:

[0018] Figure 1 This is a schematic diagram of the evaporator in this invention;

[0019] Figure 2 This is a schematic diagram of the present invention;

[0020] Figure 3 This is a schematic diagram of the evaporator after the shell has been removed in this invention;

[0021] Figure 4 This is a schematic diagram of the uniformly distributed component in this invention;

[0022] Figure 5 This is a schematic diagram of the guide plate in this invention;

[0023] Figure 6 For the present invention Figure 1 Enlarged view of B in the middle;

[0024] Figure 7 For the present invention Figure 1 Enlarged view of C in the middle;

[0025] Figure 8 This is a schematic diagram of the membrane repair head in this invention;

[0026] Figure 9 For the present invention Figure 1 A magnified view of A in the middle.

[0027] In the diagram: 1. Evaporator; 101. Discharge chamber; 102. Evaporation chamber; 103. Liquid distribution chamber; 104. Uniform distribution component; 105. Guide plate; 106. Flow divider; 107. Heat exchange tube; 108. Guide rod; 109. Film filling head; 1091. Liquid collecting cylinder; 1092. Overflow trough; 1093. Overflow pipe; 1094. Overflow ring; 1095. Annular perforation; 110. Overflow cover; 111. Connecting pipe; 112. Guide cover; 113. Liquid inlet head; 114. Divider plate; 2. Separator; 3. First two-position three-way valve; 4. Circulation pump; 5. Second two-position three-way valve; 6. Compression pump. Detailed Implementation

[0028] 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.

[0029] Please see Figures 1-6 A landfill leachate resource recovery treatment device includes an evaporator 1, which is connected to a second two-position three-way valve 5. The second two-position three-way valve 5 has two inlets and one outlet. The outlet is connected to the evaporator 1 via a pipeline. One inlet is connected to a leachate storage device, and the other inlet is connected to a circulating pump 4. The lower end of the evaporator 1 is connected to a separator 2, and the lower end of the separator 2 is connected to a first two-position three-way valve 3. The inlet of the first two-position three-way valve 3 is connected to the separator 2, and one outlet of the first two-position three-way valve 3 is connected to a treatment device. The liquid storage device is connected, and another liquid outlet is connected to the liquid inlet of the circulation pump 4. A filter device is provided between the circulation pump 4 and the liquid outlet to filter out the precipitated crystals. The top of the separator 2 is connected to the compression pump 6. The gas outlet of the compression pump 6 is connected to the evaporator 1. A filter structure is provided between the compression pump 6 and the separator 2 to filter out impurities carried in the secondary steam. The positions of the evaporator 1, separator 2, first two-position three-way valve 3, circulation pump 4, second two-position three-way valve 5 and compression pump 6 are flexibly set according to actual needs. The corresponding support frame is omitted in this invention.

[0030] After the leachate is fed into the evaporator 1 in portions, the second two-position three-way valve 5 and the first two-position three-way valve 3 are switched to be connected to the circulation pump 4. The evaporator 1 heats the leachate (the side wall of the evaporator 1 is also connected to an external steam source to form initial steam), forming a gas-liquid mixture. After the gas-liquid mixture enters the separator 2, the steam is drawn in and pressurized by the compression pump 6, and the liquid is drawn in by the circulation pump 4 and pumped back into the evaporator 1. The compressed steam enters the evaporator 1 and quickly liquefies and releases heat, heating the heating tubes in the evaporator 1. At the same time, the condensed water flows out from the side wall of the evaporator 1 and is recovered.

[0031] Evaporator 1 is divided by upper and lower partitions, forming a liquid distribution chamber 103, an evaporation chamber 102, and an exhaust chamber 101 from top to bottom. The three chambers are relatively independent. The evaporation chamber 102 is equipped with densely packed heat exchange tubes 107, and a condensate outlet is provided at the bottom of the evaporation chamber 102 (due to the angle, ...). Figure 1 and Figure 2 (Not shown in the image) Heat exchange tube 107 connects discharge chamber 101 and liquid distribution chamber 103. The side wall of evaporation chamber 102 is connected to compression pump 6. Liquid distribution chamber 103 is provided with a uniform distribution element 104 and a guide plate 105. The guide plate 105 is located above the uniform distribution element 104. The uniform distribution element 104 is provided with multiple conical grooves. The bottom of the conical grooves is a uniform distribution opening, which is connected to each heat exchange tube 107. Under the action of gravity, the percolating liquid in heat exchange tube 107 flows through the heat exchange tube 107. A liquid film is formed on the inner wall. A guide rod 108 is provided inside the heat exchange tube 107. The guide rod 108 passes through the uniform distribution member 104 and the guide plate 105. The guide plate 105 guides the percolate to the guide rod 108. A film-forming head 109 is provided at the bottom of the guide rod 108. The film-forming head 109 guides the percolate to the inner wall of the heat exchange tube 107 to form a film, so as to avoid the inner wall of the heat exchange tube 107 drying out. The film-forming head 109 is located at the bottom 1 / 2-1 / 3 of the heat exchange tube 107.

[0032] During evaporation, the leachate flows into the evaporator 1, and the liquid is evenly guided by the distributor 104 to the inner wall of the heat exchange tube 107, forming a liquid film. The outer wall of the heat exchange tube 107 contacts the steam, absorbing the heat from the condensation of the steam to heat the liquid film. Generally, the liquid film dries up mostly at the bottom 1 / 3. In this embodiment, to achieve faster evaporation efficiency, a thinner liquid film is formed at the top, and the drying point is moved upward. Therefore, the film replenishment head 109 replenishes the film at the bottom 1 / 2-1 / 3 of the heat exchange tube 107 to prevent the liquid film from drying out. On the one hand, a more aggressive evaporation strategy can be adopted at the middle and upper end of the heat exchange tube 107 (e.g., controlling the liquid film at 0.1). The liquid film is thinned to 0.15-0.25 mm, forming a thinner liquid film on the inner wall of the heat exchange tube 107, thus improving evaporation efficiency. At the lower end of the heat exchange tube 107 (where the liquid film thickness may be close to 0.1 mm), a film is replenished (replenished to 0.15-0.2 mm) to ensure the liquid film thickness and prevent it from drying out. On the other hand, the flow rate of the liquid film is more controllable. For example, a thin-film-at-the-top and thick-film-at-the-bottom liquid film strategy can be used. The thin film corresponds to a small amount of low-speed steam flowing at the upper end, reducing the probability of the film being blown off by the steam. The thick film corresponds to the high-speed steam flowing at the lower end, ensuring the flow rate of the thick film. This can better flush the lower end of the heat exchange tube 107 and reduce the probability of scaling on the heat exchange tube 107.

[0033] Please see Figures 7-8 The membrane filling head 109 includes a liquid collecting cylinder 1091 fixedly connected to the guide rod 108. The guide rod 108 is a plastic rod. The liquid flows along the outer wall of the guide rod 108 and eventually flows into the liquid collecting cylinder 1091. Due to the large drop difference between the membrane filling head 109 and the guide plate 105, the liquid flows along the guide rod 108. The viscosity of the guide rod 108 can be used to reduce the liquid flow rate, and it is also easy to clean. The liquid collecting cylinder 1091 can seal off the droplets splashed by the falling liquid. Figure 6For easier observation, the gap between the liquid collecting cylinder 1091 and the guide rod 108 is magnified. An overflow groove 1092 is provided on the outer side of the liquid collecting cylinder 1091. The liquid collecting cylinder 1091 is connected to the overflow groove 1092 through an overflow pipe 1093. The overflow pipe 1093 is inclined downwards. To improve the stability of the overflow groove 1092, a support frame is also provided. The film-forming head 109 has a sufficiently large perforation to ensure steam passage. The upper end of the guide rod 108 is fixedly connected to the flow divider plate 106, and the lower end is fixedly connected to the bottom of the heat exchange tube 107. The connection point is perforated to avoid clogging the heat exchange tube 107. Overflow... An overflow ring 1094 is provided on the outer wall of the tank 1092. The distance between the overflow ring 1094 and the inner wall of the heat exchange tube 107 is 0.15-0.25mm. The overflow ring 1094 is made of elastic material and is inclined outward from top to bottom. The bottom of the overflow ring 1094 has an annular hollow 1095 at the connection between it and the overflow tank 1092, so that the overflow ring 1094 can be folded inward. The liquid overflowing from the overflow tank 1092 can form a liquid film of 0.15-0.25mm. When too much liquid accumulates on the overflow ring 1094, it deforms under the action of liquid gravity and forms a thicker film.

[0034] Please see Figure 1 , Figures 3-6 The uniformly distributed component 104 is a cylindrical body with a bottom. Its inner wall has flanges corresponding to the guide plate 105 and the flow divider 106, respectively. After the guide plate 105 and the flow divider 106 are installed on the flanges, they form three closed cavities. The lower closed cavity is connected to the heat exchange tube 107, the middle closed cavity is connected to the guide rod 108 through the guide shroud 112, and the upper closed cavity is connected to the second two-position three-way valve 5. The flow divider 106 has a partition plate forming two sets of grooves. One set of grooves connects to the middle closed cavity. The closed cavity is connected, and the various tanks in the same group are connected by pipes. Another group of tanks is connected to the lower closed cavity through a connecting pipe 111. The connecting pipe 111 and the slots are evenly distributed, so that the liquid falls relatively evenly. The upper end of the liquid distribution chamber 103 is provided with a liquid inlet head 113 corresponding to the two groups of tanks. The liquid flowing in through the second two-position three-way valve 5 is divided into two liquid inlets 113. The flow rate of the liquid inlet head 113 is controlled by a solenoid valve, which independently regulates the amount of liquid flowing into the heat exchange tube 107 and the guide rod 108.

[0035] In order to make the liquid flowing into the heat exchange tube 107 more uniform, the uniform distribution member 104 is provided with an overflow hood 110 corresponding to the position of the heat exchange tube 107, and the overflow hood 110 faces the position where no connecting pipe 111 is provided.

[0036] Please see Figure 9The guide plate 105 is provided with a guide shroud 112 at the position corresponding to the guide rod 108. The bottom of the guide shroud 112 is an elastic ring. The guide shroud 112 allows the liquid to flow along the guide rod 108. In other embodiments, the guide rod 108 can be fixedly installed on a lifting plate. Its bottom is connected to the heat exchange tube 107 or the lower partition through a sliding sleeve. The lifting plate can lift the guide rod 108 to adjust the position of the membrane head 109.

Claims

1. A landfill leachate resource recovery treatment device, comprising an evaporator (1), a separator (2), a circulation pump (4), and a compression pump (6), wherein the gas-liquid mixture in the evaporator (1) flows into the separator (2), the liquid in the separator (2) is directly discharged or returned to the evaporator (1) via the circulation pump (4), and the secondary steam in the separator (2) is returned to the evaporator (1) via the compression pump (6), characterized in that: The evaporator (1) is formed from top to bottom as a liquid distribution chamber (103), an evaporation chamber (102) and a discharge chamber (101). The evaporation chamber (102) is provided with dense heat exchange tubes (107). The side wall of the evaporation chamber (102) is connected to the compression pump (6). The liquid distribution chamber (103) is provided from bottom to top with a uniform distribution member (104) and a guide plate (105). The uniform distribution member (104) is provided with multiple uniform distribution ports corresponding to the heat exchange tubes (107). The heat exchange tubes (107) are fitted with a guide rod (108). The guide rod (108) passes through the uniform distribution member (104) and the guide plate (105). The guide plate (105) guides the leachate to the guide rod (108). The bottom of the guide rod (108) is provided with a film replenishing head (109). The film replenishing head (109) guides the leachate to the inner wall of the heat exchange tube (107) to replenish the liquid film. The membrane repair head (109) includes an overflow groove (1092), and an overflow ring (1094) is provided on the outer wall of the overflow groove (1092). The minimum distance between the overflow ring (1094) and the inner wall of the heat exchange tube (107) is 0.15-0.25 mm. The overflow ring (1094) is made of elastic material and is inclined from top to bottom outward. The bottom of the overflow ring (1094) has an annular hollow (1095) at the connection between it and the overflow groove (1092). The membrane repair head (109) also includes a liquid collection cylinder (1091) fixedly connected to the guide rod (108). The liquid flows along the outer wall of the guide rod (108) and finally flows into the liquid collection cylinder (1091). The liquid collection cylinder (1091) is connected to the overflow groove (1092) through an overflow pipe (1093).

2. The landfill leachate resource recovery treatment equipment according to claim 1, characterized in that, The membrane head (109) is located at the bottom 1 / 2-1 / 3 of the heat exchange tube (107).

3. The landfill leachate resource recovery treatment equipment according to claim 1, characterized in that, The guide plate (105) is provided with a guide shroud (112) at the position corresponding to the guide rod (108), and the bottom of the guide shroud (112) is an elastic ring.

4. The landfill leachate resource recovery treatment equipment according to claim 3, characterized in that, The uniform distribution component (104) is a cylindrical body with a bottom. The inner wall is provided with flanges corresponding to the guide plate (105) and the flow divider (106). After the guide plate (105) and the flow divider (106) are installed on the flanges, they form three closed cavities. The lower closed cavity is connected to the heat exchange tube (107), and the middle closed cavity is connected to the guide rod (108) through the guide shroud (112).

5. The landfill leachate resource recovery treatment equipment according to claim 4, characterized in that, The diversion plate (106) is provided with a partition plate, which forms two sets of slots. Each slot in the same set is connected by a pipe. One set of slots is connected to the middle closed cavity through a perforated slot, and the other set of slots is connected to the lower closed cavity through a connecting pipe (111). The upper end of the liquid distribution chamber (103) is provided with a liquid inlet head (113) corresponding to the two sets of slots. The flow rate of the liquid inlet head (113) is controlled by a solenoid valve.

6. The landfill leachate resource recovery treatment equipment according to claim 5, characterized in that, The uniform distribution member (104) is provided with an overflow hood (110) that is offset from the connecting pipe (111) at the position corresponding to the heat exchange tube (107).

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