Evaporation concentration and cooling crystallization vacuum system

Abstract

The utility model discloses an evaporation concentration and cooling crystallization vacuum system, which relates to the technical field of vacuum salt production, and comprises a reservoir and a support, the support is arranged on the outer side of the reservoir, a mixing condenser is arranged above the support, a last-effect secondary steam pipe is arranged above the mixing condenser, and a second-effect secondary steam pipe is arranged above the last-effect secondary steam pipe. A cooling water pipe is arranged on the left side of the mixing condenser, a first drainage pipe is arranged below the mixing condenser and above the water storage tank, a roots vacuum pump is arranged on the right side of the mixing condenser, and the mixing condenser is connected with an air inlet of the roots vacuum pump through an air inlet pipe. Non-condensable steam and non-condensable gas are conveyed into the mixing condenser through the last-effect secondary steam pipe, and circulating cooling water is conveyed into the mixing condenser through the cooling water pipe so as to cool the non-condensable steam and the non-condensable gas, so that the condensed cooling water flows into the water storage tank through the first water drainage pipe; and the purpose of primary cooling and condensation of non-condensable steam and non-condensable gas is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum salt production, in particular to an evaporation concentration and cooling crystallization vacuum system. Background Art

[0002] In the natural salt purification process, such as the salt industry, the purified brine needs to be concentrated in a multi-effect evaporator to reach a saturated concentration before cooling and crystallization, and solid salt is obtained after solid-liquid separation and drying. In the production process of potassium nitrate, the nearly saturated potassium nitrate aqueous solution needs to be cooled quickly in the crystallizer. The solubility of potassium nitrate decreases with temperature, and potassium nitrate crystals are precipitated by rapid cooling to meet the production requirements.

[0003] Taking the salt industry as an example, the advantages and disadvantages of the vacuum system in the existing vacuum salt production process are explained: In order to make full use of the energy of secondary steam, the concentration of brine is usually carried out in a multi-effect evaporator, and the heating source of the post-effect evaporator is the secondary steam and exhaust steam of the previous effect, until the last effect, generally four to six effects. Under complex and harsh process conditions such as large air volume, high vacuum, mixed gas containing a large amount of steam, non-condensable gas and water mist, and corrosive gas, ordinary vacuum pumps are difficult to meet the above requirements. However, the steam jet vacuum pump process is used in the concentration process, and the process and results are the same. The widely used steam jet vacuum pumping method has very low energy efficiency, and the workplace must have a steam gas source and a cooling water source. It has poor economic and social benefits. Therefore, an evaporation concentration and cooling crystallization vacuum system is needed to improve the above shortcomings. Utility Model Content

[0004] The utility model aims to provide an evaporation concentration and cooling crystallization vacuum system to solve the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] An evaporation concentration and cooling crystallization vacuum system comprises a water reservoir and a bracket, wherein the bracket is located outside the water reservoir, a mixing condenser is arranged above the bracket, a final effect secondary steam pipe is arranged above the mixing condenser, a cooling water pipe is arranged on the left side of the mixing condenser, a first drain pipe is arranged below the mixing condenser and located above the water reservoir, a Roots vacuum pump is arranged on the right side of the mixing condenser, the mixing condenser and the air inlet of the Roots vacuum pump are connected through an air inlet pipe, a gas condenser is arranged on the right side of the Roots vacuum pump, the air outlet of the Roots vacuum pump is connected to the gas condenser through an air outlet pipe, a water outlet pipe is arranged on the upper part of the front end surface of the gas condenser, a water inlet pipe is arranged on the lower part of the front end surface of the gas condenser, a fore-stage pump is arranged on the right side of the gas condenser, the gas condenser discharge port is connected to the fore-stage pump through a collecting pipe, an emptying pipe is arranged on the right side of the fore-stage pump, a water collecting part is fixedly arranged below the collecting pipe, and the water reservoir and the water collecting part are connected through a second drain pipe.

[0007] As a further solution of the utility model: the outer end of the first drain pipe extends into the water reservoir.

[0008] As a further solution of the utility model: a vacuum gauge is arranged on the air intake pipe.

[0009] As a further solution of the utility model: the gas condenser is a water spray cooler or a fin-type tube cooler.

[0010] As a further solution of the utility model: the front-stage pump is a water ring vacuum pump or a Roots pump.

[0011] As a further solution of the utility model: a muffler is provided at the discharge port of the front-stage pump.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] 1. The first drain pipe is sealed with water through the water reservoir, and the final secondary steam pipe delivers non-condensable steam and non-condensable gas to the mixed condenser. Circulating cooling water is delivered to the mixed condenser through the cooling water pipe to cool the non-condensable steam, so that the condensed cooling water flows into the water reservoir through the first drain pipe, thus completing the purpose of initial cooling and condensation of the non-condensable steam and non-condensable gas;

[0014] 2. The uncondensed steam and non-condensable gas are fed to the gas condenser through the Roots vacuum pump. The gas condenser performs secondary cooling and condensation on the uncondensed steam and non-condensable gas. The water outlet pipe and the water inlet pipe cooperate to cool the gas condenser, thereby improving the cooling efficiency of the gas condenser.

[0015] 3. The second drain pipe is water-sealed by the high-level water seal method. The outlet of the second drain pipe is inserted below the liquid level of the water reservoir. The sealed water column in the pipe balances the pressure of the vacuum system and the atmosphere. Therefore, only water is discharged but no air is exhausted to prevent condensate from occupying the air flow channel, thereby improving the cooling efficiency of the device and improving the practicality of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the utility model.

[0017] Figure 2 It is a schematic diagram of the main structure of an embodiment of the utility model.

[0018] Figure 3 It is a schematic diagram of a partial three-dimensional structure of an embodiment of the utility model.

[0019] Figure 4 It is a schematic diagram of an embodiment of the utility model during operation.

[0020] Notes on the accompanying drawings: 1. Water reservoir; 2. Bracket; 3. Mixing condenser; 4. Last-effect secondary steam pipe; 5. First drain pipe; 6. Cooling water pipe; 7. Vacuum gauge; 8. Air inlet pipe; 9. Roots vacuum pump; 10. Air outlet pipe; 11. Gas condenser; 12. Water outlet pipe; 13. Water inlet pipe; 14. Return air cooling pipe; 15. Collecting pipe; 16. Water collecting part; 17. Second drain pipe; 18. Fore-stage pump; 19. Drain pipe. DETAILED DESCRIPTION

[0021] The following embodiments will be combined with the accompanying drawings to describe the utility model in detail. In the drawings or descriptions, similar or identical parts use the same reference numerals, and in actual applications, the shape, thickness or height of each component can be enlarged or reduced. The various embodiments listed in the utility model are only used to illustrate the utility model, and are not used to limit the scope of the utility model. Any obvious modifications or changes made to the utility model do not depart from the spirit and scope of the utility model.

[0022] Example

[0023] See also Figures 1 to 4In an embodiment of the utility model, an evaporation concentration and cooling crystallization vacuum system comprises a water reservoir 1 and a bracket 2, wherein the bracket 2 is located outside the water reservoir 1, a mixing condenser 3 is arranged above the bracket 2, a final-effect secondary steam pipe 4 is arranged above the mixing condenser 3, a cooling water pipe 6 is arranged on the left side of the mixing condenser 3, a first drain pipe 5 is arranged below the mixing condenser 3 and located above the water reservoir 1, wherein the outer end of the first drain pipe 5 extends into the water reservoir 1, the first drain pipe 5 is water-sealed by the water reservoir 1, the final-effect secondary steam pipe 4 transports non-condensable steam and non-condensable gas into the mixing condenser 3, and circulating cooling water is transported to the mixing condenser 3 through the cooling water pipe 6 to cool the non-condensable steam and non-condensable gas, so that the condensed cooling water flows into the water reservoir 1 through the first drain pipe 5, thereby completing the purpose of initial cooling and condensation of the non-condensable steam and non-condensable gas.

[0024] A Roots vacuum pump 9 is arranged on the right side of the mixing condenser 3, and the mixing condenser 3 and the air inlet of the Roots vacuum pump 9 are connected through an air inlet pipe 8. A vacuum gauge 7 is arranged on the air inlet pipe 8. A gas condenser 11 is arranged on the right side of the Roots vacuum pump 9, and the air outlet of the Roots vacuum pump 9 is connected to the gas condenser 11 through an air outlet pipe 10. The gas condenser 11 is a water spray cooler or a fin-type tube cooler. A water outlet pipe 12 is arranged on the upper part of the front end surface of the gas condenser 11, and a water inlet pipe 13 is arranged on the lower part of the front end surface of the gas condenser 11. Uncondensed steam and non-condensable gas are fed to the gas condenser 11 through the Roots vacuum pump 9. The gas condenser 11 performs secondary cooling and condensation on the uncondensed steam and non-condensable gas. The water outlet pipe 12 and the water inlet pipe 13 cooperate to cool the gas condenser 11, thereby improving the cooling efficiency of the gas condenser 11.

[0025] A fore-stage pump 18 is arranged on the right side of the gas condenser 11. The fore-stage pump 18 is a water ring vacuum pump or a Roots pump. The discharge port of the gas condenser 11 is connected to the fore-stage pump 18 through a collecting pipe 15. An air passage leading to the working chamber is opened on the inner side of the Roots vacuum pump 9. The air passage is connected to the collecting pipe 15 through a return air cooling pipe 14 (the inlet position of the cooling gas on the pump body is the position where the pump suction has been completed and the exhaust has not yet started. At this time, the gas pressure in the pump is the same as the suction port pressure. Because the discharge port pressure is higher than the suction pressure, the existence of the pressure difference can cause the gas to automatically reflux. This The cooled gas is transported to the working chamber of the Roots vacuum pump 9 through the return air cooling pipe 14 to cool the rotor of the Roots vacuum pump 9, so as to avoid heat accumulation at the exhaust port of the Roots vacuum pump 9, which may cause the rotor to expand and get stuck due to high temperature. Compared with the steam jet vacuum pump, the Roots vacuum pump 9 can save energy and water, and also protect the environment. An exhaust pipe 19 is arranged on the right side of the fore-stage pump 18, and the uncondensed steam and non-condensable gas in the collecting pipe 15 are discharged to the atmosphere through the exhaust pipe 19 via the fore-stage pump 18.

[0026] A water collecting part 16 is fixedly arranged below the collecting pipe 15, and the water reservoir 1 and the water collecting part 16 are connected by a second drain pipe 17. A negative pressure environment is created in the gas condenser 11 and the collecting pipe 15 by a front pump 18. The increasing condensate therein needs to be discharged in time, and the second drain pipe 17 is water-sealed by a high-level water seal method. The outlet of the second drain pipe 17 is inserted below the liquid level of the water reservoir 1. The sealed water column in the pipe balances the pressure of the vacuum system and the atmosphere. Therefore, only water is drained but not exhausted to prevent the condensate from occupying the air flow channel, thereby improving the cooling efficiency of the device and improving the practicability of the device.

[0027] When the device is in use, the front pump 18 is started to create a negative pressure environment in the gas condenser 11 and the collecting pipe 15, water is introduced into the gas condenser 11 through the water inlet pipe 13, and the water is discharged to the outside through the water outlet pipe 12 to cool the gas condenser 11, and the non-condensable steam is transported to the mixing condenser 3 through the final secondary steam pipe 4, and circulating cooling water is transported to the mixing condenser 3 through the cooling water pipe 6 to cool the non-condensable steam, so that the condensed cooling water flows into the water reservoir 1 through the first drain pipe 5, and the uncondensed steam is fed into the Roots vacuum pump 9 through the air inlet pipe 8. The vacuum gauge 7 on the air inlet pipe 8 monitors the pressure, and the Roots vacuum pump 9 is turned on after reaching the preset start-up pressure. Pump 9, thereby avoiding overloading of the Roots vacuum pump 9 motor, and then the gas condenser 11 cools the uncondensed steam and non-condensable gas, and the cooled gas and cooling water are fed to the collecting pipe 15. The cooled gas is divided into two paths, one of which flows back to the pump body of the Roots vacuum pump 9 through the return gas cooling pipe 14 to cool the rotor of the Roots pump, and is discharged from the gas outlet of the Roots vacuum pump 9 to the gas condenser 11 after mixing with the suction air flow, and the other gas flows into the front pump 18, which relays the gas to be discharged to the atmosphere through the exhaust pipe 19, and the condensed water is fed to the water reservoir 1 through the water collecting part 16 and the second drain pipe 17, thereby completing the whole process of treating the non-condensable steam and non-condensable gas.

[0028] The cooling crystallization process is essentially the same as the brine concentration process. The difference is that the cooling medium changes from secondary steam to hot solution. Also, a large amount of steam is generated under vacuum. The steam takes away the heat, cools the solution, and crystals precipitate. A large amount of steam, non-condensable gas and other gases need to be extracted and condensed under high vacuum. The process is the same as brine concentration, so the vacuum system structure is the same.

[0029] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0030] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An evaporation concentration and cooling crystallization vacuum system, comprising a water reservoir (1) and a support (2), characterized in that: The support (2) is located outside the water reservoir (1), a mixing condenser (3) is arranged above the support (2), a final-effect secondary steam pipe (4) is arranged above the mixing condenser (3), a cooling water pipe (6) is arranged on the left side of the mixing condenser (3), a first drain pipe (5) is arranged below the mixing condenser (3) and located above the water reservoir (1), a Roots vacuum pump (9) is arranged on the right side of the mixing condenser (3), the mixing condenser (3) and the air inlet of the Roots vacuum pump (9) are connected via an air inlet pipe (8), a gas condenser (11) is arranged on the right side of the Roots vacuum pump (9), and a gas outlet pipe (10) is arranged at the bottom of the mixing condenser (3). ) connect the gas outlet of the Roots vacuum pump (9) to the gas condenser (11); a water outlet pipe (12) is provided at the upper part of the front end surface of the gas condenser (11); a water inlet pipe (13) is provided at the lower part of the front end surface of the gas condenser (11); a fore-stage pump (18) is provided on the right side of the gas condenser (11); the gas condenser (11) outlet is connected to the fore-stage pump (18) through a collecting pipe (15); an emptying pipe (19) is provided on the right side of the fore-stage pump (18); a water collecting part (16) is fixedly provided below the collecting pipe (15); and the water reservoir (1) and the water collecting part (16) are connected through a second drain pipe (17).

2. The evaporation concentration and cooling crystallization vacuum system according to claim 1, characterized in that: The outer end of the first drainage pipe (5) extends into the water reservoir (1).

3. The evaporation concentration and cooling crystallization vacuum system according to claim 1, characterized in that: The air inlet pipe (8) is provided with a vacuum gauge (7).

4. The evaporation concentration and cooling crystallization vacuum system according to claim 3, characterized in that: The gas condenser (11) is a water spray cooler or a fin-type tube cooler.

5. The evaporation concentration and cooling crystallization vacuum system according to claim 4, characterized in that: The fore pump (18) is a water ring vacuum pump or a Roots pump.

6. The evaporation concentration and cooling crystallization vacuum system according to any one of claims 1 to 5, characterized in that: The discharge port of the front pump (18) is provided with a muffler.

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