FLASH PREHEATER

Abstract

The present invention discloses a flash preheater, which includes a plurality of flash tanks and a preheating tank, wherein said plurality of flash tanks are connected in series to form a multi-stage flash and steam with a gradually decreasing temperature is generated; said preheater tank includes an inner cylinder and an outer casing, a pipe for slurry circulation is formed in the inner cylinder, an outer casing is coaxially installed on the outside of the inner cylinder, and an intermediate layer area is formed between the outer casing and the inner cylinder, said intermediate layer area is axially divided into a steam area corresponding to and connected with the flash tank, the adjacent steam areas are interconnected, and steam with a gradually increasing temperature is introduced into the steam area according to the flow direction of the slurry.When the slurry is fed into the inner cylinder, the steam with a higher temperature is fed into the interlayer area to exchange heat with the slurry, then enters the adjacent interlayer area to mix with the steam with a lower temperature and continue to exchange heat with the slurry, and so on, so that the steam with a higher temperature can achieve repeated heat exchange and make maximum use of its heat.

Description

FLASH PREHEATER Invention Engineering Field This invention relates to the technical part of heating early minerals, and particularly with flash preheaters. Background of the Invention Nickel laterite ore is an aggregate of several minerals resembles1 loose clay formed through weathering long term, leaching, impregnation, changes, and processes other geological studies on nickel-containing olivine bedrock in tropical or subtropical regions for a long period of time. This process is accompanied by metal components such as nickel, cobalt, chromium, magnesium, and aluminum. Currently, the hydrometallurgical route by leaching using sulfuric acid under temperature and temperature conditions high pressure is one of the main melting processes for laterite nickel ore. The slurry resulting from the leaching must be cooled and reduced pressure before entering the solids separation process next liquid. The flash tank is the main equipment for this cooling and pressure drop. After flash evaporation, will produce a large amount of high-temperature steam. Currently, the route Hydrometallurgy of laterite nickel ore generally uses evaporation three-story flash, which will also produce steam on three different temperatures. Patent CN117120150A provides a combined heat exchange system flash tank and preheater for leaching nickel laterite ore, which includes a high pressure reactor, preheating tower, and flash tank. The preheater tower is connected with a port high pressure reactor feed, while the flash tank connected to the high-pressure reactor outlet port and also connected to the preheating tower via steam pipes. Each tiers of flash tanks are correspondingly equipped with turrets first stage preheater to preheat the ore gradually. However, the previously disclosed technology has the following problem: the temperature of the steam produced by flash evaporation the first stage and second stage flash evaporation are relatively high, and even though it has passed through the preheating tower, the steam is still contains a large amount of heat. If it is immediately released, this will will cause energy waste. Brief Description of the Invention The purpose of this application is to address the shortcomings existing technical and propose a flash preheater for use resolve technical issues related to low utilization rates heat in existing slurry preheating technology. To achieve these technical objectives, this application uses the following technical solutions: This application provides a flash preheater, which includes: Several flash tanks, connected in sequence to forming multi-stage flash evaporation, and each produces steam with a gradually decreasing temperature, as well as Preheater tank, which includes an inner cylinder and a casing outside, pipes for slurry circulation are formed in the inner cylinder, and the outer sheath is coaxially wrapped around the outside Inner cylinder, so that a squeeze area is formed between the casings outer and inner cylinders. This clamping area is axially divided into several steam areas that correspond to and are connected with individual flash tanks, as well as adjacent steam areas interconnected. Steam with a gradually increasing temperature introduced into the steam area along the slurry flow direction. In some embodiments, the inner cylinder is tilted, the channel The feed inlet is provided at the lower end of the inner cylinder, and the channel Ejection exit is provided at the upper end of the inner cylinder. In some embodiments, multiple annular baffle plates provided between the outer casing and the inner cylinder, and the plate annular baffles divide the interlayer area into several areas steam along the axial direction, and a through hole is provided on the annular baffle plates to connect adjacent steam areas. In some embodiments, the flash tank has an inlet fluid, fluid outlet, and outlet port, channel liquid inlet is used to enter the liquid to be flashed, The fluid outlet is used to remove fluid after flash process, and the ejection port is used to eject steam formed during the flashing process. In some embodiments, the number of flash tanks is three, namely the first flash tank, the second flash tank, and the flash tank third, which is connected sequentially. In some embodiments, two annular baffle plates divide the the intermediate layer area becomes the first vapor area, the second vapor area, and third steam area, and third steam area, second steam area, and area The first steam is arranged along the direction of slurry transport. The steam area first connected to the discharge port of the flash tank First, the second steam area is connected to the outlet port of the second flash tank, and the third steam area is connected to the porta discharge from the third flash tank. In some embodiments, a non-return valve is provided in the orifice. through the annular baffle plate, and this one-way valve only allows steam flow in the opposite direction of transport mineral materials. In some embodiments, the first pipe, the second pipe, and the third is provided in the inner cylinder, both ends of the first pipe connected to the first steam area, both ends of the second pipe are connected to second steam area, and both ends of the third pipe are connected to the steam area third. In some embodiments, the inner cylinder is made of a material heat conductor. In some embodiments, the outer surface of the outer sheath is covered by heat insulating cotton. Compared to previously disclosed technologies, the tool The flash preheater provided by the present invention includes several flash tanks and preheat tanks. Several tanks The flashes are connected sequentially to form a multi-stage flash evaporation, and each stage produces steam with the temperature decreasing gradually. Preheating tank includes an inner cylinder and an outer casing, where the pipe for Slurry circulation is formed in the inner cylinder, where the casing outer is coaxially enclosed on the outside of the inner cylinder. An intermediate layer area is formed between the outer casing and the cylinder. deep, where the area of ​​this intermediate layer is axially divided into several steam areas corresponding to and connected to flash tanks, as well as adjacent steam areas are interconnected. Steam with gradually increasing temperature is introduced into steam area along the direction of slurry flow. When the slurry is introduced into the inner cylinder, steam with a higher temperature inserted into the intermediate layer area to exchange heat with Sslurry, then enter the adjacent intermediate layer area to mixed with lower temperature steam and continues heat exchange with the slurry, so that the steam has a higher temperature high can achieve heat exchange repeatedly and make maximum use of the heat. The above description only provides a general technical overview of this invention. For a clearer understanding of the technical method this invention and its implementation in accordance with the contents of the description complete 1invention, preferred embodiment of this invention explained in detail below with reference to the figures. Specific implementations of the present invention are provided in detail by the following embodiments and their drawings. Short Description of Image Figure 1 is a schematic diagram of the heating device structure. overview provided by the present invention. Figure 2 is a schematic diagram of the heating tank structure. beginning in another embodiment. Reference Number Explanation: 1 — Flash tank, la — liquid inlet, lb — outlet liquid, 1c - discharge port, 11 - first flash tank, 12 - second flash tank, 13 - third flash tank, 2 - heating tank beginning, 21 - inner cylinder, 211 - first pipe, 212 - second pipe, 213 - third pipe, 22 - outer sheath, 23 - intermediate layer area, 23a - first steam area, 23b - second steam area, 23c - third steam area, 24 — annular baffle plate Complete Description of the Invention In order that the objectives, technical solutions and advantages of this invention can be understood more clearly, this invention is explained more the following details are images and their manifestations. It should be understood that The specific embodiments described herein are used only for describes the present invention and is not intended to limit this invention. Referring to Figure 1 which is a schematic diagram of flash preheater structure in an embodiment of the present invention. The present invention provides a flash preheater, comprising: several flash tanks (1) and one preheat tank (2). Several flash tanks (1) are connected in series to form a multi-stage flash evaporation, and each stage produces steam with the temperature gradually decreasing. Preheater tank (2) includes an inner cylinder (21) and an outer casing (22), where the pipe for the circulation of the slurry formed in the inner cylinder (21), and outer casing (22) is coaxially wrapped outside the cylinder in (21). Between the outer casing (22) and the inner cylinder (21) an intermediate layer area (23) is formed, where the intermediate layer area (23) divided axially into corresponding steam areas and connected to the flash tank (1) one by one, and the steam area which close together connected to each other. Steam with a temperature that gradually increases introduced into the steam area along the slurry flow direction. In the present invention, the slurry is introduced into a cylinder in (21), and steam with a higher temperature is introduced into the intermediate layer area (23) for exchanging heat with the slurry, then enters the adjacent intermediate layer area (23) for mixes with lower temperature steam and continues the exchange heat with slurry, and so on. In this way, the steam temperature is higher high can do some heat exchange and take advantage of full heat. The flash tank (1) has a liquid inlet (la), a drain (la). fluid output (lb), and outlet port (1c). Inlet liquid (la) is used to enter the liquid to be processed, The fluid outlet (1b) is used to drain fluid. that has finished flash processing, and the output port (le) used to remove steam formed during the flashing process. In this example, the number of flash tanks (1) is three, namely first flash tank (11), second flash tank (12), and tank third flash (13). First flash tank (11), second flash tank (12), and the third flash tank (13) are connected in sequence. The liquid inlet from the first flash tank (11) is connected to high-pressure reactor, and slurry leached from the reactor high pressure passes through the first flash tank (11), flash tank second (12), and third flash tank (13) respectively, and enter the next processing step after being removed from third flash tank (13). First flash tank (11), flash tank second (12), and third flash tank (13) can release pressure slurry leached from the high-pressure reactor in stages to avoid excessive pressure on the flash tank, which useful to protect each flash tank (1). It is understood that in other embodiments, the number of flash tanks (1) unlimited, for example, can be two, four, or more than four. The number of flash tanks can be determined based on needs. true and unlimited pressure relief overkill here. In this embodiment, the inner cylinder (21) is made of a material which conducts heat, which can quickly transfer steam heat to the slurry in the inner cylinder (21). For extend the slurry heat exchange time and increase heat exchange efficiency, the inner cylinder (21) is tilted, and the inlet is arranged at the lower end of the inner cylinder (21), and the outlet is arranged at the higher end of the cylinder in (21). The ore enters the inner cylinder (21) from the bottom end, accumulates gradually, and eventually overflows from the tip higher. This can effectively extend the time The ore is in the inner cylinder (21) and undergoes heat exchange adequate. The outer surface of the outer casing (22) is covered with cotton. heat insulation to prevent heat loss from steam. A plurality of annular baffles (24) are arranged between the outer casing (22) and inner cylinder (21). An annular baffle (24) separates the areas the intermediate layer (23) becomes a vapor area along the axial direction. Holes- a through hole is opened in the annular baffle (24) to connect adjacent steam area. In this embodiment, two annular baffles (24) divide the area the intermediate layer (23) becomes the first vapor area (23a), the second vapor area (23b), and the third steam area (23c). The third steam area (23c), steam area second (23b), and the first steam area (23a) are arranged along the direction slurry transport. The first steam area (23a) is connected to the port discharge from the first flash tank (11), second steam area (23b) connected to the discharge port of the second flash tank (12), and the third steam area (23c) is connected to the outlet port from the tank third flash (13). In actual production, the temperature of the first steam released from the first flash tank (11) is about 200”C, the second steam temperature discharged from the second flash tank (12) is about 150”C, and the temperature of the third steam discharged from the third flash tank (13) is about 110”C. The third steam is released from the flash tank the third (13) is introduced into the third steam area (23c) and exchanged heat with slurry. The third steam that has finished exchanging heat is ejected, and the slurry flows to the appropriate area second steam (23b). The second steam released from the second flash tank (12) is introduced into the second vapor area (23b) and exchanges heat with slurry. The second steam that has finished exchanging heat enters the area third steam (23c) to continue the heat exchange. The slurry has finished exchanging heat, it is further heated and flows to the area corresponding to the first steam area (23a). The first steam removed from the first flash tank (11) is put in first vapor area (23a) and exchanges heat with the slurry. Second steam which has finished exchanging heat enters the second steam area (23b) to continue the heat exchange, and the slurry completes three heat exchange. The temperature is gradually increased and sent to high pressure reactor. Steam in the first steam area (23a), steam in the second steam area (23b), and the steam in the third steam area (23c) will also flows through the first pipe (211), the second pipe (212), and the second pipe (212). third (213) in a row, which can increase uniformity of ore temperature and avoid large temperature differences between the inner layer and the outer layer of ore. The beneficial effects of this invention are as follows: This invention includes flash tanks and preheat tanks, some Flash tanks are connected in series to form a multi-flash stages, and steam with decreasing temperature is produced continuously. consecutive. The preheater tank includes an inner cylinder and outer casing, pipes for slurry circulation are formed inside inner cylinder, outer casing is coaxially wrapped in outside the inner cylinder, an intermediate layer area is formed between outer casing and inner cylinder, the area of ​​the interlayer is divided axial into the corresponding steam area and connected to flash tank, and the adjacent steam area is connected. Steam with increasing temperatures are introduced into the steam area throughout direction of slurry flow. When the slurry is introduced into the inner cylinder, steam with a higher temperature is introduced into the layer area between to exchange heat with the slurry, and then enter adjacent intermediate layer area to mix with the steam lower temperature and continue heat exchange with the slurry. In this way, higher temperature steam can do some of the work. heat exchange and make full use of its heat. The specific implementation method of the present invention is described above does not limit the scope of protection of this invention. Any changes and modifications that are in accordance with the concept technical aspects of the invention must be included within the scope protection of claims for this invention.

Claims

1. A flash preheater, characterized by including: e Several flash evaporation tanks, connected in series sequentially to form multi-stage flash evaporation, each of which produces steam at a different temperature increasingly decreasing: and e Preheater tank, which includes the inner cylinder and outer casing, where the inner cylinder forms the pipe path for slurry circulation, the outer sheath is sheathed coaxial outside the inner cylinder, and the inner layer area formed between the outer casing and the inner cylinder, the intermediate layer area is divided axially into areas steam corresponding to and connected to the tank flash evaporation, adjacent areas of vapor collide with each other connected, steam with increasing temperature introduced into the steam area along the flow direction slurry.

2. The flash preheater according to claim 1, characterized in that the inner cylinder is tilted, the feed inlet is arranged in the bottom end of the inner cylinder, and the discharge outlet arranged at the top end of the inner cylinder. . The flash preheater according to claim 2, characterized in that several annular baffle plates are provided between the outer casings and inner cylinder, these annular baffle plates divide the area the intermediate layer into several vapor areas along the axial direction, and through holes are provided in the annular baffle plate to connect adjacent steam areas. . The flash preheater according to claim 3, characterized in that the tank flash has a fluid inlet, fluid outlet, and outlet port, fluid inlet is used for insert the liquid to be flashed, the liquid outlet used to remove liquid that has been finished flashing, and the outlet port is used to release the vapor formed by the flash process.

10. . The flash preheater according to claim 4, characterized in that the amount three flash tanks, namely the first flash tank, the second flash tank the second flash, and the third flash tank are connected together sequentially. . The flash heating device according to claim 5, characterized in that said device includes two annular baffle plates, which divide the coating area between being the first steam area, the second steam area, and the second steam area third, third steam area, second steam area, and first steam area arranged along the direction of slurry transport, the first steam area connected to the steam exhaust port of the first flash tank, the second steam area is connected to the steam exhaust port from the tank second flash, and the third steam area is connected to the port steam discharge from the third flash tank. . The flash preheater according to claim 3, characterized in that the valve one way is provided on the through hole of the annular baffle plate, and this one-way valve only allows steam to flow in the direction which is opposite to the direction of ore transport. . The flash preheater according to claim 6, characterized in that The inner cylinder is equipped with a first pipe, a second pipe, and third pipe, both ends of the first pipe are connected to the steam area First, both ends of the second pipe are connected to the second steam area, and both ends of the third pipe are connected to the third steam area. . The flash preheater according to claim 7, characterized in that The inner cylinder is made of heat-conducting material. The flash preheater according to claim 7, characterized in that the outer surface of the outer sheath is covered with cotton heat insulation.

Images