Energy-saving device of normal-pressure ammonia still

Abstract

The utility model relates to the technical field of waste heat utilization of ammonia stilling towers, in particular to an energy-saving device of a normal-pressure ammonia stilling tower. Comprising an ammonia distillation system, an ammonia steam heat exchange condensation system and a steam secondary generation system, the ammonia distillation system comprises an ammonia distillation tower, a wastewater pump, an ammonia water heat exchanger and a separated water heat exchanger, and the ammonia steam heat exchange condensation system comprises a heater hot side part, an ammonia water condenser, an ammonia water tank and an ammonia water pump. The steam secondary generation system comprises a heater cold side part, a circulating pump, a separator and a steam compressor, and the ammonia distillation system, the ammonia steam heat exchange condensation system and the steam secondary generation system are all connected through pipelines; in order to overcome the defects in the prior art, the utility model provides an energy-saving device of a normal-pressure ammonia distillation tower, which can effectively recover waste heat of ammonia steam and ammonia distillation wastewater in the ammonia distillation process to reduce the running cost of ammonia distillation, and is moderate in investment and short in investment cost recovery period.

Description

TECHNICAL FIELD

[0001] The utility model relates to the waste heat utilization technical field of ammonia still, specifically relates to an energy-saving device of atmospheric ammonia still. BACKGROUND

[0002] In the coking production process, part of the ammonia water cooled from the coke oven gas is sprayed to cool the coke oven gas and smokeless coal charging in the coke oven gas collector, and the excess part is sent to the ammonia still as residual ammonia water. After recovering ammonia vapor by steam, the ammonia still wastewater is sent to the phenol cyanide wastewater treatment station for treatment. In the atmospheric ammonia still process, about 80 kg / t of low-pressure steam is consumed for heating, and the 90-95℃ ammonia vapor generated after the residual ammonia water is still is directly introduced into the pre-cooling tower of the desulfurization system, or is cooled by cooling water to produce concentrated ammonia water and then sent to the desulfurization reaction tank as an alkali source. The ammonia still wastewater discharged from the bottom of the still is first heated to 85℃ by exchanging heat with the residual ammonia water, and then cooled to below 35℃ by cooling water before being sent out of the device. In this ammonia still process, the heat energy in the ammonia vapor and the ammonia still wastewater is not recovered and utilized, resulting in energy waste and high operating cost of the ammonia still device.

[0003] Prior art one: Chinese patent CN 117327514 A discloses a method for recovering waste heat from ammonia still, which uses the ammonia vapor from the ammonia still to heat the ammonium sulfate mother liquor, thereby recovering part of the heat energy of the ammonia vapor and reducing the steam consumption of the ammonium sulfate device, but it does not reduce the steam consumption of the ammonia still device itself.

[0004] The prior art one has the following technical defects: this technical solution mainly uses the heat of the ammonia vapor from the ammonia still to heat the ammonium sulfate mother liquor, thereby recovering part of the heat energy of the ammonia vapor and reducing the steam consumption of the ammonium sulfate device, but it does not reduce the steam consumption of the ammonia still device itself.

[0005] Prior art two: Chinese patent CN 203768059 U discloses an energy-saving system for producing process cooling water using waste heat from coking ammonia still wastewater, which includes a wastewater pump, a residual ammonia water heat exchanger, a first inlet of the heat exchanger connected to a residual ammonia water tank, a second inlet of the heat exchanger connected to the outlet of the wastewater pump, a refrigeration machine, and the like. The second outlet of the residual ammonia water heat exchanger is connected to the first inlet of a first heat exchanger, the first outlet of the first heat exchanger is connected to a wastewater deep treatment device, the first inlet and the first outlet of the first heat exchanger are connected, the second outlet of the first heat exchanger is connected to the first medium inlet of a heat pump unit, the first medium outlet of the heat pump unit is connected to the second inlet of the first heat exchanger, the second inlet and the second outlet of the first heat exchanger are connected, the second medium outlet of the heat pump unit is connected to the medium inlet of the refrigeration machine, and the medium return water outlet of the refrigeration machine is connected to the second medium inlet of the heat pump unit. This system recovers the waste heat from the ammonia still wastewater, generates steam (or hot water) by the heat pump as the driving heat source of the refrigeration machine, and reduces energy consumption.

[0006] The prior art two has the following technical defects: the technical scheme recovers only 30%-40% of the total ammonia distillation waste heat as heat for production by using the waste heat of the ammonia distillation waste water, has low heat utilization rate, poor energy-saving effect, large investment in the heat pump device, and long investment cost recovery period.

[0007] Therefore, there is an urgent need to design an energy-saving device for the atmospheric ammonia distillation tower to solve the problems of the prior art, such as low heat utilization rate, poor energy-saving effect, large investment in the heat pump device, and long investment cost recovery period. Content of the utility model

[0008] In view of the problems in the prior art, the utility model aims to provide an energy-saving device for the atmospheric ammonia distillation tower.

[0009] The utility model solves the technical problems by adopting the following technical scheme: an energy-saving device for the atmospheric ammonia distillation tower, comprising an ammonia distillation system, an ammonia vapor heat exchange and condensation system, and a steam secondary generation system, wherein the ammonia distillation system comprises an ammonia distillation tower, a waste water pump, an ammonia water heat exchanger, and a separated water heat exchanger, the ammonia vapor heat exchange and condensation system comprises a heater hot side part, an ammonia water condenser, an ammonia water tank, and an ammonia water pump, and the steam secondary generation system comprises a heater cold side part, a circulating pump, a separator, and a steam compressor, and the ammonia distillation system, the ammonia vapor heat exchange and condensation system, and the steam secondary generation system are all connected by pipes.

[0010] Specifically, the ammonia water inlet at the upper part of the ammonia distillation tower is connected to the ammonia water heat exchanger, and the remaining ammonia water is preheated by the ammonia water heat exchanger and then enters the ammonia distillation tower.

[0011] Specifically, the waste water pump inlet is communicated with the ammonia distillation waste water outlet at the bottom of the ammonia distillation tower, the waste water pump outlet is communicated with the hot side inlet of the ammonia water heat exchanger through a pipe, the hot side outlet of the ammonia water heat exchanger is communicated with the hot side inlet of the separated water heat exchanger through a pipe, and the ammonia distillation waste water is discharged from the hot side outlet of the separated water heat exchanger.

[0012] Specifically, the inlet of the heater hot side part is communicated with the ammonia vapor outlet at the top of the ammonia distillation tower through a pipe, the hot side outlet of the heater is communicated with the hot side inlet at the top of the ammonia water condenser through a pipe, the hot side outlet at the bottom of the ammonia water condenser is communicated with the inlet of the ammonia water tank through a pipe, the outlet of the ammonia water tank is communicated with the inlet of the ammonia water pump through a pipe, the outlet of the ammonia water pump is communicated with the backflow port at the top of the ammonia distillation tower through a pipe, and the excess ammonia water is sent out from the outlet pipe of the ammonia water pump.

[0013] Specifically, the cold side inlet of the ammonia water condenser is communicated with the cooling water inlet pipe, and the cold side outlet is communicated with the cooling water return pipe.

[0014] Specific is, the separation water heat exchanger cold side import with the outside original water pipeline communication, separation water heat exchanger cold side export is through pipeline with circulating pump import pipeline, and the heater top cold side export is through pipeline with separator import communication, and the separator bottom export is through pipeline with circulating pump import communication, and the circulating pump export is with heater cold side import communication, and the circulating pump heater and separator form closed loop circulation, and the separator top gas export is through pipeline with steam compressor import communication, and the steam compressor export is through pipeline with ammonia stripping tower bottom direct steam import communication.

[0015] The utility model has the following beneficial effects:

[0016] The energy-saving device of the atmospheric ammonia stripping tower designed by the utility model uses ammonia steam and waste heat of ammonia stripping waste water to generate secondary steam, and then uses a steam compressor to increase the temperature and pressure of the secondary steam, and the heated secondary steam is directly sent into the ammonia stripping tower for heating, which can save more than 40% of the low-pressure steam consumption, has obvious energy-saving effect, and significantly reduces the ammonia stripping cost.

[0017] The energy-saving device of the atmospheric ammonia stripping tower designed by the utility model uses crude benzene separation water generated in the crude benzene production process as raw water to replace desalted water to generate secondary steam, consumes the crude benzene separation waste water, recovers part of the crude benzene, saves water resources, and reduces the water treatment cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the structural schematic diagram of the energy-saving device of the atmospheric ammonia stripping tower.

[0019] In the figure: 1-ammonia stripping tower;2-heater, 2.1-heater hot side, 2.2-heater cold side;3-ammonia water condenser;4-ammonia water tank;5-ammonia water pump;6-circulating pump;7-separator;8-steam compressor;9-waste water pump;10-ammonia water heat exchanger;11-separation water heat exchanger. DETAILED DESCRIPTION

[0020] The technical scheme in the embodiments of the utility model will be further clearly and completely explained in detail in combination with the drawings in the embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0021] For example, Figure 1As shown, an energy-saving device of an atmospheric ammonia distillation tower includes an ammonia distillation system, an ammonia vapor heat exchange and condensation system, and a steam secondary generation system. The ammonia distillation system includes an ammonia distillation tower 1, a wastewater pump 9, an ammonia water heat exchanger 10, and a separated water heat exchanger 11. The ammonia vapor heat exchange and condensation system includes a heater hot side 2.1 part, an ammonia water condenser 3, an ammonia water tank 4, and an ammonia water pump 5. The steam secondary generation system includes a heater cold side 2.2 part, a circulating pump 6, a separator 7, and a steam compressor 8. The ammonia distillation system, the ammonia vapor heat exchange and condensation system, and the steam secondary generation system are all connected through pipelines.

[0022] The ammonia distillation tower 1 in the ammonia distillation system is used to release ammonia dissolved in circulating water through heat transfer of a heat carrier. The ammonia distillation tower 1 absorbs ammonia water preheated by the ammonia water heat exchanger 10. The bottom of the ammonia distillation tower 1 is provided with an ammonia distillation wastewater outlet connected with the wastewater pump 9. The wastewater pump 9 is used to discharge wastewater into the ammonia water heat exchanger 10. The ammonia water heat exchanger 10 discharges wastewater into the separated water heat exchanger 11. The wastewater is discharged from the ammonia distillation system through the separated water heat exchanger 11. The ammonia vapor heat exchange and condensation system is used to heat exchange and condense ammonia vapor. The inlet of the heater hot side 2.1 is connected with the steam outlet at the top of the ammonia distillation tower 1 through a pipeline. The outlet of the heater hot side 2.1 is connected with the ammonia water condenser 3. The heater hot side 2.1 and the ammonia water condenser 3 are respectively used for heating and condensing. The ammonia water discharged from the ammonia water condenser 3 flows into the ammonia water tank 4. The ammonia water tank 4 is used to temporarily store ammonia water. The outlet of the ammonia water tank 4 is connected with the ammonia water pump 5 through a pipeline. The ammonia water pump 5 is used to return ammonia water to the ammonia water return port at the top of the ammonia distillation tower 1 and discharge excess ammonia water. The steam secondary generation system is used to evaporate the recovered ammonia water through the ammonia distillation tower 1 again, so as to maximize the utilization. The separated water heat exchanger 11 sends raw water to the circulating pump 6. The heater cold side 2.2 part is connected with the circulating pump 6. The bottom outlet of the separator 7 is connected with the circulating pump 6 through a pipeline. The circulating pump 6 sends raw water back to the heater cold side 2.2. The circulating pump 6, the heater, and the separator 7 form a closed loop circulation. The top of the separator 7 is provided with a gas outlet connected with the inlet of the steam compressor 8 through a pipeline. The steam compressor 8 is used to deliver steam to the direct steam inlet at the bottom of the ammonia distillation tower 1 through a pipeline.

[0023] 1. The bottom of the ammonia distillation tower 1 is provided with a low-pressure steam inlet as a supplement of the device heat source.

[0024] 2. The steam compressor 8 is a multi-stage centrifugal compressor, which is used to increase the temperature and pressure of the secondary steam.

[0025] 3. The raw water used in the cold side inlet of the separated water heat exchanger 11 is desalted water, preferably the crude benzene separation water generated in the crude benzene production process.

[0026] 4. The temperature of the raw water at the hot side outlet of the separated water heat exchanger 11 is ≥80℃, so as to reduce the heat loss caused by the subsequent raw water temperature rise.

[0027] 5. The temperature of the secondary steam at the inlet of the vapor compressor 8 is 87-92℃;

[0028] 6. The temperature of the secondary steam at the outlet of the vapor compressor 8 is 115-125℃, and the pressure is ≥50KPa (gauge).

[0029] The utility model is not limited to the above-mentioned embodiment, any person should know the structural change made under the inspiration of the utility model, any technical scheme with the same or similar to the utility model falls into the protection scope of the utility model.

[0030] The technical, shape, structure parts not described in the utility model are the known technology.

[0031] It should be noted that, in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0032] Although the embodiments of the present utility model have been shown and described, it is to be understood that the embodiments can be varied, modified, replaced and changed in many ways without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. An energy-saving device for an atmospheric pressure ammonia stripping tower, characterized in that, The system includes an ammonia stripping system, an ammonia vapor heat exchange and condensation system, and a secondary steam generation system. The ammonia stripping system includes an ammonia stripping tower, a wastewater pump, an ammonia water heat exchanger, and a water separator. The ammonia vapor heat exchange and condensation system includes a heater hot side section, an ammonia water condenser, an ammonia water tank, and an ammonia water pump. The secondary steam generation system includes a heater cold side section, a circulating pump, a separator, and a steam compressor. The ammonia stripping system, the ammonia vapor heat exchange and condensation system, and the secondary steam generation system are all connected by pipelines.

2. The energy-saving device for the atmospheric pressure ammonia stripping tower according to claim 1, characterized in that, The ammonia water inlet at the top of the ammonia stripping tower is connected to an ammonia water heat exchanger, which preheats the remaining ammonia water before it enters the ammonia stripping tower.

3. The energy-saving device for the atmospheric pressure ammonia stripping tower according to claim 1, characterized in that, The wastewater pump inlet is connected to the ammonia stripping wastewater outlet at the bottom of the ammonia stripping tower. The wastewater pump outlet is connected to the hot side inlet of the ammonia water heat exchanger through a pipeline. The hot side outlet of the ammonia water heat exchanger is connected to the hot side inlet of the separation water heat exchanger through a pipeline. The ammonia stripping wastewater is discharged from the device through the hot side outlet of the separation water heat exchanger.

4. The energy-saving device for the atmospheric pressure ammonia stripping tower according to claim 1, characterized in that, The inlet of the heater's hot side is connected to the ammonia vapor outlet at the top of the ammonia stripping tower via a pipe. The outlet of the heater's hot side is connected to the inlet of the top of the ammonia water condenser via a pipe. The outlet of the ammonia water condenser's bottom hot side is connected to the inlet of the ammonia water tank via a pipe. The outlet of the ammonia water tank is connected to the inlet of the ammonia water pump via a pipe. The outlet of the ammonia water pump is connected to the reflux port at the top of the ammonia stripping tower via a pipe. Excess ammonia water is sent out of the device through the outlet pipe of the ammonia water pump.

5. The energy-saving device for the atmospheric pressure ammonia stripping tower according to claim 4, characterized in that, The cold-side inlet of the ammonia condenser is connected to the cooling water inlet pipe, and the cold-side outlet is connected to the cooling water return pipe.

6. The energy-saving device for the atmospheric pressure ammonia stripping tower according to claim 1, characterized in that, The cold-side inlet of the water separator is connected to the raw water pipeline from outside the boundary. The cold-side outlet of the water separator is connected to the inlet pipeline of the circulating pump through a pipeline. The cold-side outlet at the top of the heater is connected to the inlet of the separator through a pipeline. The bottom outlet of the separator is connected to the inlet of the circulating pump through a pipeline. The outlet of the circulating pump is connected to the cold-side inlet of the heater. The circulating pump, heater, and separator form a closed loop. The gas outlet at the top of the separator is connected to the inlet of the steam compressor through a pipeline. The outlet of the steam compressor is connected to the direct steam inlet at the bottom of the ammonia stripping tower through a pipeline.

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