A flash preheating device

Abstract

The present invention discloses a flash preheating device, including multiple flash tanks and a preheating tank, wherein the multiple flash tanks are connected in sequence to form a multi-stage flash, and steam with gradually decreasing temperature is produced respectively; the preheating tank includes an inner cylinder and an outer sleeve, a pipeline for slurry circulation is formed in the inner cylinder, the outer sleeve is coaxially sleeved on the outside of the inner cylinder, an interlayer area is formed between the outer sleeve and the inner cylinder, the interlayer area is axially divided into steam areas corresponding to and connected to the flash tanks, adjacent steam areas are connected, and steam with gradually increasing temperature is introduced into the steam areas along the flow direction of the slurry. When the slurry is introduced into the inner cylinder, the higher temperature steam is introduced into the interlayer area to exchange heat with the slurry, and then enters the adjacent interlayer area to mix with the lower temperature steam and continue to exchange heat with the slurry, and so on, so that the higher temperature steam can achieve multiple heat exchanges and fully utilize its heat.

Description

[0001] Description

[0002] A FLASH PREHEATING DEVICE

[0003] Field Of Invention

[0004] The present invention relates to the technical field of mineral preheating, and in particular to a flash preheating device .

[0005] Background

[0006] Laterite nickel ore is a loose clay-like multi-mineral aggregate formed by long-term weathering, leaching, impregnation, alteration and other geological processes of nickel-bearing olivine bedrock in tropical or subtropical regions , accompanied by metal components such as nickel , cobalt, chromium, magnesium, and aluminum . At present , the hydrometallurgical route of sul furic acid leaching under high temperature and high pressure conditions is one of the mainstream smelting processes of laterite nickel ore . The leached slurry must be cooled and depressuri zed before entering the next solid-liquid separation process . The flash tank is the main device for cooling and depressuri zation treatment . A large amount of high-temperature steam will be generated after flash evaporation . At present , the hydrometallurgical route of laterite nickel ore generally adopts three-stage flash evaporation, which will also produce steam at three di f ferent temperatures .

[0007] Patent CN117120150A provides a laterite nickel ore leaching flash tank and preheater combined heat exchange system, including an autoclave , a preheating tower and a flash tank . The preheating tower is connected to the feed port of the autoclave . The flash tank is connected to the discharge port of the autoclave , and the flash tank is also connected to the preheating tower through a steam pipe . Each level of flash tank is correspondingly provided with each level of preheating tower to preheat the ore step by step .

[0008] However, the above-mentioned prior art has the following problems : the steam temperature generated by the first-stage flash evaporation and the second-stage flash evaporation is relatively high, and after passing through the preheating tower, it still has a large amount of heat , and directly discharging it will cause energy waste .

[0009] Summary

[0010] The obj ective of this invention is to overcome the above technical deficiencies and propose a flash preheating device to solve the technical problem of low heat utilization rate in the existing slurry preheating technology .

[0011] In order to achieve the above technical obj ectives , this invention adopts the following technical solutions :

[0012] This invention provides a flash preheating device , which comprises :

[0013] Multiple flash tanks , which are connected in sequence to form multi-stage flash evaporation, and respectively produce steam with gradually decreasing temperature ; and

[0014] A preheating tank, which comprises an inner cylinder and an outer sleeve , wherein a pipeline for slurry circulation is formed in the inner cylinder, and the outer sleeve is coaxially sleeved on the outside of the inner cylinder, and an interlayer area is formed between the outer sleeve and the inner cylinder, wherein the interlayer area is axially divided into steam areas corresponding to and connected to the flash tanks one by one , and adj acent steam areas are connected, and steam with gradually increasing temperature is respectively introduced into the steam areas along the slurry flow direction .

[0015] In some embodiments , the inner cylinder is tilted, a feed inlet is provided at the lower end of the inner cylinder, and a discharge outlet is provided at the higher end of the inner cylinder .

[0016] In some embodiments , multiple annular baf fles are provided between the outer sleeve and the inner cylinder, the annular baf fles divide the interlayer area into multiple steam areas along the axial direction, and through holes are provided on the annular baf fles to connect adj acent steam areas .

[0017] In some embodiments , the flash tank has a liquid inlet , a liquid outlet , and an exhaust port , wherein the liquid inlet is used to introduce the liquid to be flashed, the liquid outlet is used to discharge the liquid after flashing, and the exhaust port is used to discharge the steam formed by flashing . In some embodiments , the number of the flash tanks is three , namely, the first flash tank, the second flash tank, and the third flash tank, and the first flash tank, the second flash tank, and the third flash tank are connected in sequence .

[0018] In some embodiments , the two annular baf fles divide the interlayer area into a first steam area, a second steam area, and a third steam area, and the third steam area, the second steam area, and the first steam area are arranged along the slurry transportation direction; the first steam area is connected to the exhaust port of the first flash tank, the second steam area is connected to the exhaust port of the second flash tank, and the third steam area is connected to the exhaust port of the third flash tank .

[0019] In some embodiments , a one-way valve is provided at the through hole of the annular baf fle , and the one-way valve only allows steam to flow in the opposite direction of the ore transport .

[0020] In some embodiments , a first pipe , a second pipe , and a third pipe are provided in the inner cylinder, and two ends of the first pipe are connected to the first steam area, two ends of the second pipe are connected to the second steam area, and two ends of the third pipe are connected to the third steam area .

[0021] In some embodiments , the inner cylinder is made of heat-conducting material .

[0022] In some embodiments , the outer sleeve is covered with heat-insulating cotton .

[0023] Compared with the prior art , the flash preheating device provided by the present invention includes multiple flash tanks and a preheating tank, wherein the multiple flash tanks are connected in sequence to form a multi-stage flash, and each of them produces steam with a gradually decreasing temperature ; the preheating tank includes an inner cylinder and an outer sleeve , wherein a pipeline for the circulation of slurry is formed in the inner cylinder, wherein the outer sleeve is coaxially sleeved on the outside of the inner cylinder, and an interlayer area is formed between the outer sleeve and the inner cylinder, wherein the interlayer area is axially divided into steam areas corresponding to and connected to the flash tanks , and adj acent steam areas are connected, wherein steam with gradually increasing temperature is introduced into the steam areas along the flow direction of the slurry . When the slurry is introduced into the inner cylinder, the higher temperature steam is introduced into the interlayer area to exchange heat with the slurry, and then enters the adj acent interlayer area to mix with the lower temperature steam and continue to exchange heat with the slurry, and so on, so that the higher temperature steam can achieve multiple heat exchanges and fully utili ze its heat .

[0024] The above description is only an overview of the technical solution of the present invention . In order to have a clearer understanding of the technical means of the present invention and to implement them in accordance with the contents of the detailed description, the preferred embodiments of the present invention are described in detail below with reference to the drawings . The speci fic implementation of the present invention are given in detail by the following embodiments and their drawings .

[0025] Brief Description Of The Drawings

[0026] FIG . 1 is a schematic diagram of the structure o f the flash preheating device provided by the present invention;

[0027] FIG . 2 is a schematic diagram of the structure of the preheating tank in another embodiment .

[0028] Description of the reference numerals :

[0029] 1- flash tank, la-liquid inlet , Ib-liquid outlet , Ic-exhaust port , 11- first flash tank, 12 -second flash tank, 13-third flash tank, 2-preheating tank, 21-inner cylinder, 211- first pipel ine , 212-second pipeline , 213-third pipeline , 22-outer sleeve , 23-interlayer area, 23a- first steam area, 23b-second steam area, 23c-third steam area, 24-annular baf fle .

[0030] Detailed Description

[0031] In order to make the obj ective , technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conj unction with the drawings and embodiments . It should be understood that the speci fic embodiments described herein are only used to explain the present invention and are not used to limit the present invention . Please refer to FIG . 1 , which is a schematic diagram of the structure of a flash preheating device in an embodiment of the present invention .

[0032] The present invention provides a flash preheating device , including : multiple flash tanks 1 and a preheating tank 2 , wherein the multiple flash tanks 1 are connected in sequence to form a multi-stage flash, and each of which produces steam with a gradually decreasing temperature ; the preheating tank 2 includes an inner cylinder 21 and an outer sleeve 22 , wherein a pipeline for the circulation of slurry is formed in the inner cylinder 21 , and the outer sleeve 22 is coaxially sleeved on the outs ide of the inner cylinder 21 , and an interlayer area 23 is formed between the outer sleeve 22 and the inner cylinder 21 , wherein the interlayer area 23 is axially divided into steam areas corresponding to and connected to the flash tanks 1 one by one , and adj acent steam areas are connected, and steam with gradually increasing temperature is respectively introduced into the steam areas along the slurry flow direction .

[0033] In the present invention, the slurry is introduced into the inner cylinder 21 , and the higher temperature steam is introduced into the interlayer area 23 to exchange heat with the slurry, and then enters the adj acent interlayer area 23 to mix with the lower temperature steam and continue to exchange heat with the slurry, and so on, so that the higher temperature steam can achieve multiple heat exchanges and fully utili ze its heat .

[0034] The flash tank 1 has a liquid inlet la, a liquid outlet lb and an exhaust port 1c . The liquid inlet la is used to introduce the liquid to be flashed, the liquid outlet lb is used to discharge the liquid that has completed flashing, and the exhaust port 1c is used to discharge the steam formed by flashing .

[0035] In this embodiment , the number of the flash tanks 1 is three , namely the first flash tank 11 , the second flash tank 12 and the third flash tank 13 , wherein the first flash tank 11 , the second flash tank 12 and the third flash tank 13 are connected in sequence , the liquid inlet of the first flash tank 11 is connected to the autoclave , and the slurry leached from the autoclave passes through the first flash tank 11 , the second flash tank 12 and the third flash tank 13 in sequence , and enters the next processing step after being output from the third flash tank 13 . The first flash tank 11 , the second flash tank 12 and the third flash tank 13 can release the pressure of the slurry leached from the autoclave step by step to avoid excessive pressure on the flash tank, which is beneficial to protect each of the flash tanks 1 .

[0036] It can be understood that in other embodiments , the number of the flash tanks 1 is not limited, for example , it can be two , four or more than four . The number of flash tanks can be determined according to actual pressure release requirements and is not excessively limited here .

[0037] In this embodiment , the inner cylinder 21 is made of heat-conducting material , which can quickly trans fer the heat of steam to the slurry in the inner cylinder 21 .

[0038] In order to extend the heat exchange time of the slurry and improve the heat exchange ef ficiency, the inner cylinder 21 is tilted, and an inlet is arranged on the lower end of the inner cylinder 21 , and an outlet is arranged on the higher end of the inner cylinder 21 . The ore enters the inner cylinder 21 from the lower end, gradually accumulates , and finally overflows from the higher end, which can ef fectively extend the time the ore stays in the inner cylinder 21 and perform suf ficient heat exchange .

[0039] The outer surface of the outer s leeve 22 is covered with heat insulation cotton to prevent the heat loss of the steam .

[0040] A number of annular baf fles 24 are arranged between the outer sleeve 22 and the inner cylinder 21 . The annular baf fles 24 separate the interlayer area 23 into the steam area along the axial direction . Through holes are opened on the annular baf fles 24 to connect the adj acent steam areas .

[0041] In this embodiment , the two annular baf fles 24 divide the interlayer area 23 into a first steam area 23a, a second steam area 23b, and a third steam area 23c . The third steam area 23c, the second steam area 23b, and the first steam area 23a are arranged along the slurry transportation direction; the first steam area 23a is connected to the exhaust port of the first flash tank 11 , the second steam area 23b is connected to the exhaust port of the second flash tank 12 , and the third steam area 23c is connected to the exhaust port of the third flash tank 13 . In actual production, the temperature of the first steam discharged from the first flash tank 11 is about 200 ° C, the temperature of the second steam 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 discharged from the third flash tank 13 is introduced into the third steam region 23c and exchanges heat with the slurry . The third steam that completes the heat exchange is discharged, and the slurry flows to the region corresponding to the second steam region 23b ; the second steam discharged from the second flash tank 12 is introduced into the second steam region 23b and exchanges heat with the slurry . The second steam that completes the heat exchange enters the third steam region 23c to continue the heat exchange ; and the slurry that completes the heat exchange is further heated up and flows to the region corresponding to the first steam region 23a . The first steam discharged from the first flash tank 11 is introduced into the first steam region 23a and exchanges heat with the slurry . The second steam that completes the heat exchange enters the second steam region 23b to continue the heat exchange , and the slurry completes three heat exchanges , and the temperature is gradually increased and sent to the autoclave The first steam with the highest temperature exchanges heat with the slurry three times , and the second steam with the second highest temperature exchanges heat with the slurry twice , so that the heat of the steam is fully utili zed and the utili zation rate of the heat is improved .

[0042] In this embodiment , a one-way valve is provided at the through hole of the annular baf fle 24 , and the one-way valve only allows steam to flow in the opposite direction of the ore transport . The function of the one-way valve is to limit the flow direction of the steam and avoid the flow disorder of the steam in the interlayer area 23 .

[0043] Please refer to FIG . 2 . In some other feasible embodiments , the inner cylinder 21 is provided with a first pipe 211 , a second pipe 212 , and a third pipe 213 . The two ends of the first pipe 211 are connected to the first steam region 23a, the two ends of the second pipe 212 are connected to the second steam region 23b, and the two ends of the third pipe 213 are connected to the third steam region 23c . Since the ore material is in a slurry state , when it is in the inner cylinder 21 , the ore material located in the center of the inner cylinder 21 receives less heat , and there may be a temperature di f ference between the ore material in the center and the ore material near the inner wall of the inner cylinder 21 . The first pipe 211 , the second pipe 212 , and the third pipe 213 can improve the uni formity of the ore material temperature and avoid a large temperature di f ference between the inner layer and the outer layer of the ore material .

[0044] In order to better understand the present invention, the technical solution of the present invention is described in detail below with reference to the drawings :

[0045] The slurry leached from the autoclave passes through the first flash tank 11 , the second flash tank 12 and the third flash tank 13 in sequence . The temperature of the first steam discharged from the first flash tank 11 is about 200 ° C, the temperature of the second steam discharged from the second f lash 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 discharged from the third flash tank 13 is introduced into the third steam area 23c and exchanges heat with the slurry . The third steam that completes the heat exchange is discharged, and the slurry flows to the area corresponding to the second steam area 23b ; the second steam discharged from the second flash tank 12 is introduced into the second steam area 23b and exchanges heat with the slurry . The second steam that completes the heat exchange enters the third steam area 23c . The slurry that has completed the heat exchange is further heated up and flows to the area corresponding to the first steam area 23a . The first steam discharged from the first flash tank 11 is introduced into the first steam area 23a and exchanges heat with the slurry . The second steam that has completed the heat exchange enters the second steam area 23b and continues to exchange heat . The slurry completes three heat exchanges , and the temperature increases step by step and is sent to the autoclave . The steam in the first steam area 23a, the steam in the second steam area 23b, and the steam in the third steam area 23c will also flow through the first pipe 211 , the second pipe 212 , and the third pipe 213 respectively, which can improve the uni formity of the ore temperature and avoid a large temperature di f ference between the inner layer and the outer layer of the ore . The beneficial ef fects of the present invention are as follows : it includes multiple flash tanks and preheating tanks , the multiple flash tanks are connected in sequence to form a multi-stage flash, and the steam with gradually decreasing temperature is produced respectively; the preheating tank includes an inner cylinder and an outer sleeve , a pipeline for the circulation of slurry is formed in the inner cylinder, the outer sleeve is coaxially sleeved on the outside of the inner cylinder, a interlayer area is formed between the outer sleeve and the inner cylinder, the interlayer area is axially divided into steam areas corresponding to and connected to the flash tanks , adj acent steam areas are connected, and steam with gradually increasing temperature is introduced into the steam areas along the flow direction of the slurry . When the slurry is introduced into the inner cylinder, the higher temperature steam is introduced into the interlayer area to exchange heat with the slurry, and then enters the ad acent interlayer area to mix with the lower temperature steam and continue to exchange heat with the slurry, and so on, so that the higher temperature steam can achieve multiple heat exchanges and fully utili ze its heat .

[0046] The speci fic implementation methods of the present invention described above do not constitute a limitation on the protection scope of the present invention . Any other corresponding changes and modi fications made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention .

Claims

Claims1 . A flash preheating device , characteri zed in that it comprises :Multiple flash tanks , which are connected in sequence to form multi-stage flash evaporation, and respectively produce steam with gradually decreasing temperature ; andA preheating tank, which comprises an inner cylinder and an outer sleeve , wherein a pipeline for slurry circulation is formed in the inner cylinder, and the outer sleeve is coaxially sleeved on the outside of the inner cylinder, and an interlayer area is formed between the outer sleeve and the inner cylinder, wherein the interlayer area is axially divided into steam areas corresponding to and connected to the flash tanks one by one , and adj acent steam areas are connected, and steam with gradually increasing temperature is respectively introduced into the steam areas along the slurry flow direction .2 . The flash preheating device according to claim 1 is characteri zed in that the inner cylinder is tilted, a feed inlet is arranged at the lower end of the inner cylinder, and a discharge outlet is arranged at the higher end of the inner cylinder .3 . The flash preheating device according to claim 2 is characteri zed in that multiple annular baf fles are provided between the outer sleeve and the inner cylinder, the annular baf fles divide the interlayer area into multiple steam areas along the axial direction, and through holes are provided on the annular baf fles to connect adj acent steam areas .4 . The flash preheating device according to claim 3 is characteri zed in that the flash tank has a liquid inlet , a liquid outlet and an exhaust port , the liquid inlet is used to introduce the liquid to be flashed, the liquid outlet is used to discharge the liquid that has completed flashing, and the exhaust port is used to discharge the steam formed by flashing .5 . The flash preheating device according to claim 4 is characteri zed in that the number of the flash tanks is three , namely the first flashtank, the second flash tank and the third flash tank, and the first flash tank, the second flash tank and the third flash tank are connected in sequence .6 . The flash preheating device according to claim 5 is characteri zed in that it comprises two annular baf fles , which divide the interlayer area into a first steam area, a second steam area, and a third steam area, and the third steam area, the second steam area, and the first steam area are arranged along the slurry transportation direction; the first steam area is connected to the exhaust port of the first flash tank, the second steam area is connected to the exhaust port of the second flash tank, and the third steam area is connected to the exhaust port of the third flash tank .7 . The flash preheating device according to claim 3 is characteri zed in that a one-way valve is provided at the through hole of the annular baf fle , and the one-way valve only allows steam to flow in the opposite direction of the ore transportation .8 . The flash preheating device according to claim 6 is characteri zed in that the inner cylinder is provided with a first pipe , a second pipe , and a third pipe , the two ends of the first pipe are connected to the first steam area, the two ends of the second pipe are connected to the second steam area, and the two ends of the third pipe are connected to the third steam area .9 . The flash preheating device according to claim 7 is characteri zed in that the inner cylinder is made of heat-conducting material .10 . The flash preheating device according to claim 7 is characteri zed in that the outer surface of the outer sleeve is covered with heat-insulating cotton .

Images