Microwave indirect heating ammonia still and process

Abstract

The invention relates to the technical field of ammonia distillation equipment, in particular to a microwave indirect heating ammonia distillation tower and process. Comprising a tower body, a wastewater atomization device, a microwave heating device, a liquid sealing disc, a tower disc and a dephlegmator, an atomizing nozzle of the wastewater atomizing device is mounted in the tower body and located at the middle lower part, and the atomizing nozzle downwards sprays atomized wastewater; the microwave heating device is installed outside the tower body and located below the wastewater atomization device, and atomized wastewater is flashed and vaporized through microwave heating of the microwave heating device; the liquid seal disc and the tower disc are mounted in the tower body, the liquid seal disc is positioned above the wastewater atomization device, and the tower disc is positioned above the liquid seal disc; and the dephlegmator is fixedly connected to the top of the tower body. The method has the advantages of high efficiency, low energy consumption, low cost and small environmental pollution.

Description

Technical Field

[0001] The invention relates to the technical field of ammonia distillation equipment, in particular to a microwave indirect heating ammonia distillation tower and a process. Background Art

[0002] Coking wastewater has the characteristics of high aminophenol content and poor biodegradability. It is a difficult and hot spot in the field of industrial wastewater. Its treatment usually requires flotation oil removal, solvent dephenolization, wastewater ammonia evaporation, biochemical treatment and other steps before it can meet the discharge standards. The steps before biochemical treatment are collectively referred to as pretreatment. Biochemical treatment is more sensitive to the ammonia nitrogen content and phenol content after pretreatment. The only process in pretreatment that controls the ammonia nitrogen index is the ammonia evaporation process, so ammonia evaporation is a key step in wastewater treatment.

[0003] Conventional ammonia distillation processes mainly include direct steam ammonia distillation process, thermal oil ammonia distillation process, tubular furnace ammonia distillation process and steam reboiler ammonia distillation process.

[0004] In the direct steam ammonia distillation process, steam is directly introduced from the bottom of the ammonia distillation tower, and after condensation, it is discharged together with the waste water from the bottom of the tower. The ammonia distillation process not only fails to reduce wastewater emissions, but increases the ammonia distillation wastewater by about 20%. It has low energy efficiency and increases the burden of subsequent biochemical treatment. The direct steam ammonia distillation process has low tower efficiency, high energy consumption, high cost, and severe environmental pollution.

[0005] The thermal oil ammonia distillation process uses an indirect heating ammonia distillation reboiler to supply heat to the ammonia distillation tower, and the reboiler is heated by thermal oil. The thermal oil is heated by gas in the thermal oil furnace, and is pumped to the reboiler by the hot oil pump to heat the wastewater in the ammonia distillation tower kettle. The hot oil after releasing heat is returned to the thermal oil furnace for heating and then recycled. The disadvantage is that the investment is high and the thermal oil heating furnace produces waste gas.

[0006] The tubular furnace ammonia distillation process is that the wastewater from the tower bottom is sent to the tubular furnace for heating through a circulating pump, and the resulting vapor-liquid mixture is returned to the tower for flash evaporation to generate steam as the heat source for the ammonia distillation tower. The disadvantage is that the investment is high and the ammonia distillation tubular furnace heating furnace produces waste gas.

[0007] The steam reboiler ammonia distillation process uses steam to indirectly heat the ammonia distillation reboiler to supply heat to the ammonia distillation tower, reducing the direct steam ammonia distillation wastewater. The disadvantages are high investment and unstable steam temperature, which affects the ammonia distillation operation. Summary of the invention

[0008] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a microwave indirect heating ammonia distillation tower and process, which has high efficiency, low energy consumption, low cost and little environmental pollution.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A microwave indirect heating ammonia distillation tower comprises a tower body, a wastewater atomization device, a microwave heating device, a liquid sealing disk, a tower plate and a divider; the atomization nozzle of the wastewater atomization device is installed in the tower body, located in the middle and lower part, and the atomization nozzle sprays atomized wastewater downward; the microwave heating device is installed outside the tower body, located below the wastewater atomization device, and the atomized wastewater is flash vaporized by microwave heating of the microwave heating device; the liquid sealing disk and the tower plate are installed in the tower body, the liquid sealing disk is located above the wastewater atomization device, and the tower plate is located above the liquid sealing disk; the divider is fixedly connected to the top of the tower body.

[0011] Furthermore, the tower body includes a cylinder body, a lower head and a skirt seat which are sequentially connected from top to bottom.

[0012] Furthermore, it also includes a cone section, a vertical pipe, a first vent, a second vent and a partition; the cone section is fixed in the cylinder, located below the wastewater atomization device, and the vertical pipe is fixed to the bottom of the cone section; the partition is vertically fixed in the lower head; the first vent and the second vent are fixed to the bottom of the lower head, located on both sides of the partition.

[0013] Furthermore, it also includes a raw ammonia water inlet and an ammonia gas outlet; the raw ammonia water inlet is fixedly connected to the tower wall of the tower body, located at the tower plate; the ammonia gas outlet is fixedly connected to the top of the fractionator.

[0014] Furthermore, it also includes a connecting pipe, which is fixed to the tower wall of the tower body, the top end of the connecting pipe is connected to the liquid sealing disk, and the bottom end is connected to the bottom of the tower body.

[0015] Furthermore, the microwave heating device includes a control cabinet, a microwave generator, a microwave waveguide and a temperature sensor; the microwave waveguide is fixed to the outer wall of the tower body, and the temperature sensor is placed inside the cylinder; the control cabinet is electrically connected to the microwave generator, the microwave waveguide and the temperature sensor, and the microwave generator adopts a power-adjustable microwave generator, and the microwave generator power is adjusted according to the steam temperature measured by the temperature sensor.

[0016] Furthermore, the wastewater atomization device includes an anti-vortex baffle, a wastewater outlet pipe, a wastewater pump, a connecting pipe, a wastewater inlet pipe, a spray pipe and an atomizing nozzle; the anti-vortex baffle is fixedly connected to the tower body and is located at the bottom, the wastewater outlet pipe is fixedly connected to the tower wall of the tower body at the anti-vortex baffle, the wastewater inlet pipe is fixedly connected to the tower wall in the middle and lower part of the tower body, the wastewater outlet pipe is connected to the wastewater inlet pipe through a connecting pipe, and the wastewater pump is installed on the connecting pipe; the spray pipe is installed in the tower body, the spray pipe is connected to the wastewater inlet pipe, and multiple atomizing nozzles are installed on the spray pipe.

[0017] Furthermore, the tower tray is a bubble tray, a vertical sieve plate or an inclined hole tray.

[0018] Furthermore, the reducer is a fixed tube sheet heat exchanger.

[0019] A microwave indirect heating ammonia evaporation process specifically comprises the following steps:

[0020] 1. After preheating and adding alkali, the raw ammonia water enters the upper part of the tower body through the raw ammonia water inlet. The steam at the bottom of the tower is used as a heat source to evaporate the free ammonia in the ammonia water. The evaporated ammonia gas is condensed by the fractionator at the top of the tower to obtain product ammonia gas, which is used in downstream processes. The condensate produced by the fractionator is used as reflux liquid and flows directly back into the tower.

[0021] 2. After ammonia evaporation, the wastewater flows into the bottom of the tower through the connecting pipe at the liquid seal plate. The wastewater containing tar impurities is separated at the bottom of the tower, flows through the partition to the right side of the partition, and is pumped out by the wastewater pump through the anti-vortex baffle and enters the wastewater atomization device. The impurities are discharged from the first vent and the second vent;

[0022] 3. After microwave heating by the microwave heating device, the wastewater is atomized through the atomizing nozzle, and an atomizing flash evaporation space is formed inside the cylinder. In the flash evaporation space, the pressurized wastewater is depressurized and atomized, and flash evaporated by microwave heating. A part of the steam is used for ammonia evaporation in the ammonia evaporation tower, and it contacts the raw ammonia water from the bottom of the tower plate in reverse to complete the ammonia evaporation process; a part of the atomized liquid flows downward into the cone section by gravity, flows into the bottom of the tower through the vertical pipe, and flows to the right side of the partition together with the wastewater at the bottom of the tower, and continues the atomizing flash evaporation process.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The atomizing nozzle of the wastewater atomizing device of the present invention sprays atomized wastewater downward, and the atomized wastewater is flash-vaporized by microwave heating of the microwave heating device. The atomized wastewater flash evaporation method is used to provide steam for the ammonia evaporation tower, which has high efficiency, low energy consumption, low cost, and little environmental pollution.

[0025] 2. The microwave generator of the present invention adopts a power-adjustable microwave generator, and the power of the microwave generator is adjusted according to the steam temperature measured by the temperature sensor. The heating steam temperature is stable, which is conducive to improving the efficiency of ammonia steaming and ensuring the ammonia steaming effect.

[0026] 3. The present invention uses a connecting pipe to introduce wastewater into the bottom of the tower to separate impurities such as tar and reduce equipment blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the present invention.

[0028] In the figure: 1-skirt 2-lower head 3-manhole 4-connecting pipe 5-liquid seal plate 6-cylinder 7-tower plate 8-raw ammonia water inlet 9-spraying pipe 10-atomizing nozzle 11-cone section 12-vertical pipe 13-partition 14-partition manhole 15-first vent 16-second vent 17-anti-vortex baffle 18-wastewater outlet pipe 19-wastewater pump 20-connecting pipe 21-wastewater inlet pipe 22-microwave heating device 23 divider 24-ammonia outlet 31-control cabinet 32-microwave generator 33-microwave waveguide 34-temperature sensor DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below. In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the description of the present invention, it should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0034] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0035] like Figure 1 As shown, a microwave indirect heating ammonia distillation tower includes a tower body, a wastewater atomization device, a microwave heating device 22, a liquid sealing plate 5, a tower plate 7 and a fractionator 23.

[0036] The tower body is a vertical structure, including a cylinder 6, a lower end cap 2 and a skirt 1. The lower end cap 2 is fixed to the bottom of the cylinder 6, the divider 23 is fixed to the top of the cylinder 6, and the lower end cap 2 is fixed to the skirt 1. It also includes a cone section 11, a vertical pipe 12, a first vent 15, a second vent 16, a partition 13, a raw ammonia water inlet 8, an ammonia gas outlet 24 and a connecting pipe 4. The cone section 11 is fixed to the cylinder 6, located below the microwave heating device 22, and the vertical pipe 12 is fixed to the bottom of the cone section 11. The partition 13 is vertically fixed to the lower end cap 2, and the first vent 15 and the second vent 16 are fixed to the bottom of the lower end cap 2, located on the left and right sides of the partition 13. The raw ammonia water inlet 8 is fixed to the side wall of the cylinder 6, located at the tower plate 7, and the ammonia gas outlet 24 is fixed to the top of the divider 23. The partition 13 is provided with a partition manhole 14.

[0037] The wastewater atomization device includes an anti-vortex baffle 17, a wastewater outlet pipe 18, a wastewater pump 19, a connecting pipe 20, a wastewater inlet pipe 21, a spray pipe 9 and an atomizing nozzle 10. The anti-vortex baffle 17 is fixedly connected to the tower body at the bottom, the wastewater outlet pipe 18 is fixedly connected to the side wall of the cylinder body 6 at the anti-vortex baffle 17, the wastewater inlet pipe 21 is fixedly connected to the side wall of the cylinder body 6 at the middle and lower part of the tower body, the wastewater outlet pipe 18 is connected to the wastewater inlet pipe 21 through a connecting pipe 20, and the wastewater pump 19 is installed on the connecting pipe 20. The spray pipe 9 is horizontally installed in the cylinder body 6, the spray pipe 9 is connected to the wastewater inlet pipe 21, and a plurality of atomizing nozzles 10 are installed on the spray pipe 9, and the atomizing nozzles 10 are evenly arranged in the cylinder body 6.

[0038] The microwave heating device 22 includes a control cabinet 31, a microwave generator 32, a microwave waveguide 33 and a temperature sensor 24. The microwave waveguide 33 is fixed to the side wall of the cylinder 6 between the wastewater atomization device and the cone section 11. The temperature sensor 24 is placed inside the cylinder 6. The control cabinet 31 is electrically connected to the microwave generator 32, the microwave waveguide 33 and the temperature sensor 24. The microwave generator 32 adopts a power-adjustable microwave generator, and the power of the microwave generator 32 is adjusted according to the steam temperature measured by the temperature sensor 24.

[0039] The spray pipe 9, the atomizing nozzle 10 and the lower cylinder 6 form a wastewater atomization space, and the external microwave heating device 22 forms an atomization flash vaporization space, and the atomized wastewater is flash vaporized by microwave heating.

[0040] The connecting pipe 4 is fixed to the side wall of the cylinder 6, the top and bottom of the connecting pipe 4 are connected to the liquid sealing disk 5, and the bottom is connected to the bottom of the cylinder 6. Wastewater containing tar impurities is separated at the bottom of the cylinder 6, flows through the partition 13 to the right side of the partition 13, is pumped out by the wastewater pump 19 through the anti-vortex baffle 17, enters the wastewater heating device for heating, and then enters the cylinder for atomization flash evaporation. Tar and other impurities are discharged from the first vent 15 and the vent 16.

[0041] The tray 7 is a bubble tray, a vertical sieve plate or an inclined hole tray. The reducer 23 is a fixed tube sheet heat exchanger.

[0042] A microwave indirect heating ammonia evaporation process is implemented based on the above-mentioned microwave indirect heating ammonia evaporation tower, and specifically includes the following steps:

[0043] 1. The raw ammonia water sent from the tank area enters the upper part of the tower through the raw ammonia water inlet 8 after preheating and adding alkali. The steam at the bottom of the tower is used as a heat source to evaporate the free ammonia in the ammonia water. The evaporated ammonia gas is condensed by the ammonia decompressor 23 at the top of the tower to obtain product ammonia gas, which is used in downstream processes. The condensate produced by the ammonia decompressor 23 is used as reflux liquid and directly flows back into the tower.

[0044] 2. After ammonia evaporation, the wastewater flows into the bottom of the tower body through the connecting pipe 4 at the bottom liquid seal plate 5. The wastewater containing tar impurities is separated at the bottom of the tower body, flows through the partition 13 to the right side of the partition 13, and is pumped out by the wastewater pump 19 through the anti-vortex baffle 17 and enters the wastewater atomization device. Tar and other impurities are discharged from the first vent 15 and the second vent 16.

[0045] 3. The microwave heating device 22 adopts microwave heating, the microwave generator 32 is a power-adjustable microwave generator, and the temperature sensor 34 is placed inside the cylinder 6. The power of the microwave generator is adjusted according to the steam outlet temperature measured by the temperature sensor 34. After microwave heating, the wastewater is atomized through the atomizing nozzle 10, and an atomizing flash evaporation space is formed inside the cylinder. In the flash evaporation space, the pressurized wastewater is depressurized and atomized, and flash evaporated by microwave heating. A part of the steam generated is used for ammonia evaporation in the ammonia evaporation tower, and it contacts the raw ammonia water from the bottom of the tower plate in reverse to complete the ammonia evaporation process; a part of the atomized liquid flows downward into the cone section 11 by gravity, flows into the bottom of the tower through the vertical pipe 12, and flows to the right side of the partition 13 together with the wastewater at the bottom of the tower, and continues to implement the atomizing flash evaporation process.

[0046] The invention has high efficiency, low energy consumption, low cost and little environmental pollution.

[0047] The above descriptions are only some specific implementation methods of the present invention, and the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, and they should be covered by the protection scope of the present invention.

Claims

1. A microwave indirect heating ammonia distillation tower, characterized in that: It includes a tower body, a wastewater atomizing device, a microwave heating device, a liquid sealing plate, a tower plate and a splitter; The atomizing nozzle of the wastewater atomizing device is installed in the tower body, located in the middle and lower part, and the atomizing nozzle sprays atomized wastewater downward; The microwave heating device is installed outside the tower body and below the wastewater atomization device, and the atomized wastewater is flash vaporized by microwave heating of the microwave heating device; The liquid sealing plate and the tower plate are installed in the tower body, the liquid sealing plate is located above the wastewater atomization device, and the tower plate is located above the liquid sealing plate; The divider is fixedly connected to the top of the tower body.

2. The microwave indirect heating ammonia distillation tower according to claim 1, characterized in that: The tower body comprises a cylinder body, a lower head and a skirt seat which are connected in sequence from top to bottom.

3. The microwave indirect heating ammonia distillation tower according to claim 2, characterized in that: It also includes a cone section, a vertical pipe, a first vent, a second vent and a baffle; The cone section is fixedly connected to the cylinder body and is located below the wastewater atomization device, and the vertical pipe is fixedly connected to the bottom of the cone section; The partition is vertically fixed in the lower head; The first venting port and the second venting port are fixedly connected to the bottom of the lower head and are located on both sides of the partition.

4. The microwave indirect heating ammonia distillation tower according to claim 1, characterized in that: It also includes a raw ammonia water inlet and an ammonia gas outlet; The raw ammonia water inlet is fixedly connected to the tower wall of the tower body and is located at the tower tray; The ammonia outlet is fixedly connected to the top of the fractionator.

5. The microwave indirect heating ammonia distillation tower according to claim 1, characterized in that: It also includes a connecting pipe, which is fixed to the tower wall of the tower body, the top of the connecting pipe is connected to the liquid sealing disk, and the bottom of the connecting pipe is connected to the bottom of the tower body.

6. The microwave indirect heating ammonia distillation tower according to claim 1, characterized in that: The microwave heating device comprises a control cabinet, a microwave generator, a microwave waveguide and a temperature sensor; The microwave waveguide is fixed to the outer wall of the tower body, and the temperature sensor is placed inside the cylinder; the control cabinet is electrically connected to the microwave generator, the microwave waveguide, and the temperature sensor. The microwave generator adopts a power-adjustable microwave generator, and the microwave generator power is adjusted according to the steam temperature measured by the temperature sensor.

7. The microwave indirect heating ammonia distillation tower according to claim 1, characterized in that: The wastewater atomization device comprises an anti-vortex baffle, a wastewater outlet pipe, a wastewater pump, a connecting pipe, a wastewater inlet pipe, a spray pipe and an atomization nozzle; The anti-vortex baffle is fixedly connected to the tower body and is located at the bottom. The wastewater outlet pipe is fixedly connected to the tower wall of the tower body at the anti-vortex baffle. The wastewater inlet pipe is fixedly connected to the tower wall at the middle and lower part of the tower body. The wastewater outlet pipe is connected to the wastewater inlet pipe through a connecting pipe, and the wastewater pump is installed on the connecting pipe. The spray pipe is installed in the tower body, the spray pipe is connected to the wastewater inlet pipe, and a plurality of atomizing nozzles are installed on the spray pipe.

8. The microwave indirect heating ammonia distillation tower according to claim 1, characterized in that: The tower tray is a bubble tray, a vertical sieve plate or an inclined hole tray.

9. The microwave indirect heating ammonia distillation tower according to claim 1, characterized in that: The reducer is a fixed tube sheet heat exchanger.

10. A microwave indirect heating ammonia evaporation process, which is realized based on a microwave indirect heating ammonia evaporation tower according to any one of claims 1 to 9, characterized in that: The specific steps include: 1) After being preheated and alkali-added, the raw ammonia water enters the upper part of the tower body through the raw ammonia water inlet. The steam at the bottom of the tower is used as a heat source to evaporate the free ammonia in the ammonia water. The evaporated ammonia gas is condensed by the fractionator at the top of the tower to obtain product ammonia gas, which is used in downstream processes. The condensate produced by the fractionator is used as reflux liquid and directly flows back into the tower; 2) After ammonia evaporation, the wastewater flows into the bottom of the tower body through the connecting pipe at the liquid seal plate. The wastewater containing tar impurities is separated at the bottom of the tower body, flows through the partition to the right side of the partition, and is pumped out by the wastewater pump through the anti-vortex baffle and enters the wastewater atomization device. The impurities are discharged from the first vent and the second vent; 3) After microwave heating by the microwave heating device, the wastewater is atomized through the atomizing nozzle, and an atomizing flash evaporation space is formed inside the cylinder. In the flash evaporation space, the pressurized wastewater is depressurized and atomized, and flash evaporated by microwave heating. A part of the steam is used for ammonia evaporation in the ammonia evaporation tower, and it contacts the raw ammonia water from the bottom of the tower plate in reverse to complete the ammonia evaporation process; a part of the atomized liquid flows downward into the cone section by gravity, flows into the bottom of the tower through the vertical pipe, and flows to the right side of the partition together with the wastewater at the bottom of the tower, and continues the atomizing flash evaporation process.

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