CN112079405A - Coking residual ammonia water negative pressure ammonia distillation energy-saving device - Google Patents

Abstract

The invention relates to an energy-saving device for coking residual ammonia water negative pressure ammonia distillation, comprising a pretreatment device, a residual ammonia water buffer tank, a waste oil tank, an lye tank, a mixer, a feed preheater, an ammonia distillation tower, a Boiler, sub-contractor, column top condenser, gas-liquid separator, vacuum pump, feed pump, lye pump, ammonia water pump, column bottom pump, residue pump and connecting pipelines. Described coking residual ammonia water negative pressure ammonia steaming energy-saving device, the lye mixer is arranged on the pipeline before the residual ammonia water enters the tower, the ammonia distillation tower tower top is directly connected with the sub-contractor, and is connected with the tower top condenser, gas condenser and gas separator through pipelines. The liquid separator is connected with the vacuum pump and the ammonia water pump; the side line at the bottom of the ammonia distillation tower is connected with the bottom pump and the reboiler through pipelines. The bottom of the ammonia distillation tower is provided with an external heating coil, and the bottom of the tower is connected with the residue pump through the pipeline. The invention is applied to the residual ammonia water negative pressure ammonia steaming process, and has the remarkable advantages of small investment scale, low operation cost, energy saving and consumption reduction, flexible operation, good and stable ammonia steaming wastewater index and the like.

Description

A kind of coking residual ammonia water negative pressure ammonia steaming energy-saving device

technical field

The invention belongs to the field of coal chemical industry, and particularly relates to an energy-saving device for coking residual ammonia water negative pressure ammonia steaming.

Background technique

The coal coking process will produce a certain amount of ammonia nitrogen, cyanide, sulfide, phenol and residual ammonia with high concentration of COD. The remaining ammonia water is pretreated, and then the ammonia, cyanide and other impurities in the ammonia water are removed by ammonia distillation, which meets the requirements of the sewage treatment process, and the ammonia is recovered at the same time.

The traditional ammonia steaming process adopts the method of direct steam stripping, but many years of production practice have found that there are two problems: First, the steam consumption of ammonia steaming is large, and the steam consumption is about 150-250kg/ton of remaining ammonia water, and the steam consumption accounts for the entire amount of ammonia. Coking produces a considerable part of the steam consumption; the second is that the heat source of the direct steam ammonia steaming process comes from direct steam, which greatly increases the amount of waste water in biochemical treatment. These two aspects both increase the production cost of enterprises, and at the same time do not comply with the national energy conservation and emission reduction policies, which have a certain impact on the environment. In recent years, the use of negative pressure ammonia steaming technology has gradually increased in the coal coking industry. Compared with traditional processes, negative pressure ammonia steaming technology can improve the relative volatility of components, reduce the operating temperature of the tower, and reduce the corrosiveness of the medium. Reply to equipment material requirements reduce and effectively reduce energy consumption.

CN203794660U discloses a negative pressure ammonia steaming device for coking residual ammonia water. The device uses a jet pump or a liquid ring pump in the ammonium sulfate section to form a negative pressure ammonia steaming system at the top of the ammonia steaming tower. The ammonia water desulfurization section at the top of the tower is connected with the liquid inlet of the vacuum pump to the ammonium sulfate mother liquor pipeline in the ammonium sulfate section. Using the jet pump and the liquid ring pump will introduce the working fluid, that is, the non-condensable ammonia gas is absorbed by the working fluid, so the ammonia gas product cannot be obtained, and the product structure is single. The tower kettle of the ammonia distillation tower adopts a kettle-type reboiler. After being pressurized by the tower bottom pump, the ammonia distillation wastewater enters the reboiler all the way, and exits the device all the way. Due to the high temperature of the ammonia distillation wastewater from the tower kettle, the waste of resources is caused.

Due to the complex water quality of the ammonia distillation tower, even if the remaining ammonia water is pretreated with air flotation degreasing and ceramic filters before entering the ammonia distillation tower, the long-term operation of the ammonia distillation device will still form scale-like substances, resulting in poor distillation effect and high energy consumption. , block the pipeline and form scaling in the tower.

The device has not only made breakthroughs in energy saving and emission reduction, but also reduced daily operating costs, and at the same time, negative pressure and low temperature operation determines that the material requirements of the equipment are not high, reducing the initial investment cost.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned deficiencies of the prior art, the present invention proposes a negative pressure ammonia steaming device for coking residual ammonia water, which improves product quality and production efficiency, and reduces the production cost of gas and liquid.

For achieving the above object, the technical scheme adopted in the present invention is as follows:

An energy-saving device for coking residual ammonia water negative pressure ammonia distillation, comprising a pretreatment device, residual ammonia water buffer tank, waste oil tank, lye tank, mixer, feed preheater, ammonia distillation tower, reboiler, Sub-contractor, tower top condenser, gas-liquid separator, vacuum pump, feed pump, lye pump, ammonia water pump, tower bottom pump, residue pump and connecting pipelines. Described coking residual ammonia water negative pressure ammonia steaming energy-saving device, before the residual ammonia water enters the tower, is provided with the lye mixer on the pipeline, the ammonia distillation tower tower top is directly connected with the sub-contractor, and is connected to the tower top condenser, gas condenser and gas separator through the pipeline. The liquid separator is connected with the vacuum pump and the ammonia water pump; the side line at the bottom of the ammonia distillation tower is connected with the bottom pump and the reboiler through pipelines. The bottom of the ammonia distillation tower is provided with an external heating coil, and the bottom of the tower is connected with the residue pump through the pipeline.

Further, the rectifying section in the ammonia distillation tower is provided with a high-efficiency regular plate corrugated packing, and the stripping section is provided with a high-efficiency vertical sieve tray.

Further, the non-condensable ammonia gas in the gas-liquid separator can be transported to the outside of the device by a vacuum pump, and the liquid-phase ammonia water can be transported to the ammonia water storage tank by an ammonia water pump, so as to realize the comprehensive utilization of the top product.

Further, the vacuum pump is a claw vacuum pump.

Further, the ammonia distillation wastewater at the bottom of the ammonia distillation tower is drawn into two paths through the side line of the tower bottom pump, one path is connected to the inlet of the reboiler tube side, and the other path is connected to the shell side inlet of the feed preheater, and is connected to the remaining ammonia water. After heat exchange, the wastewater from ammonia distillation is sent to the biochemical treatment section.

Further, the bottom of the ammonia distillation tower is a conical head and is accompanied by a steam coil. When the liquid at the bottom of the tower is intermittently discharged through the residue pump, steam is introduced, which can accelerate the discharge of the residue, prevent the tower kettle from scaling, and improve the distillation effect. Meet the indicators of steaming ammonia wastewater.

Compared with the prior art, the present invention has the following advantages:

1. The present invention is applied to the residual ammonia water distillation process. Compared with the prior art, the combination of a packed column and a plate column is adopted, and the operation flexibility is large and the separation efficiency is high.

2. The present invention is applied to the process of ammonia distillation with residual ammonia water, and the product structure is diversified, and high-purity ammonia gas and ammonia water can be obtained at the same time. The claw vacuum pump is used to avoid the absorption of ammonia gas by the liquid vacuum pump and the treatment of exhaust gas.

3. The present invention is applied to the ammonia distillation process of residual ammonia water, and the residual ammonia water is preheated by using the ammonia distillation wastewater produced by the side line at the bottom of the tower, which has the advantages of energy saving, consumption reduction, environmental protection and safety.

4. The present invention is applied to the residual ammonia water ammonia distillation process, and the negative pressure is used to steam ammonia, which saves the amount of steam and reduces the amount of ammonia steaming wastewater.

5. The present invention is applied to the process of ammonia distillation with residual ammonia water. The tower kettle is provided with a conical head and a steam coil to accelerate the discharge of residues, effectively prevent the tower kettle from scaling, and has high distillation efficiency.

Description of drawings

Fig. 1 is the structural representation of the present invention:

In the figure: 1. Pretreatment device, 2. Waste oil tank, 3. Surplus ammonia buffer tank, 4. Feeding pump, 5. Alkali liquor tank, 6. Alkali liquor pump, 7. Mixer, 8. Feeding pretreatment Heater, 9, Ammonia distillation tower, 10, Subcontractor, 11, Tower top condenser, 12, Gas-liquid separator, 13, Vacuum pump, 14, Ammonia water pump, 15, Column bottom pump, 16, Reboiler, 17. Residue pump.

Detailed ways

Embodiments of the present invention are further described below in conjunction with the accompanying drawings:

As shown in Figure 1, a negative pressure ammonia steaming device for residual ammonia water comprises pretreatment device 1, waste oil tank 2, residual ammonia water buffer tank 3, feed pump 4, lye tank 5, lye pump 6 connected in sequence , mixer 7, feed preheater 8, ammonia distillation tower 9, sub-contractor 10, tower top condenser 11, gas-liquid separator 12, vacuum pump 13, ammonia water pump 14, tower bottom pump 15, reboiler 16 , Residue pump 17 and connecting pipeline. The residual ammonia water negative pressure ammonia steaming device is equipped with a lye mixer on the pipeline before the residual ammonia water enters the tower. The top of the ammonia steaming column is directly connected to the sub-contractor, and is connected to the column top condenser, gas-liquid separator and vacuum pump through the pipeline. , the ammonia water pump is connected; the side line of the bottom of the ammonia distillation tower is connected with the bottom pump and the reboiler through the pipeline, the bottom of the ammonia distillation tower is provided with an external heating coil, and the bottom of the tower is connected with the residue pump through the pipeline. The rectifying section in the ammonia distillation tower is provided with high-efficiency regular plate corrugated packing, and the stripping section is provided with high-efficiency vertical sieve trays. The non-condensable ammonia gas in the gas-liquid separator at the top of the tower can be transported to the outside of the device by a claw vacuum pump, and the liquid-phase ammonia water can be transported to the ammonia water storage tank by an ammonia water pump to realize the comprehensive utilization of the top products. The ammonia distillation wastewater at the bottom of the ammonia distillation tower is drawn into two paths by the side line of the tower bottom pump. One path is connected to the tube side inlet of the reboiler, and the other path is connected to the shell side inlet of the feed preheater. After heat exchange with the remaining ammonia water The post-distillation ammonia wastewater is sent to the biochemical treatment section. The bottom of the ammonia distillation tower is a conical head and is accompanied by a steam coil. When the liquid at the bottom of the tower is intermittently discharged through the residue pump, steam is introduced, which can accelerate the discharge of the residue, prevent the tower kettle from scaling, improve the distillation effect, and meet the needs of the distillation process. Ammonia wastewater indicators.

The working process of the present invention is as follows: as shown in FIG. 1 , the residual ammonia water of the raw material enters the residual ammonia water buffer tank 3 after being degreasing and filtered by the pretreatment device 1, and the impurities such as oil and phenol enter the waste oil tank 2. The pretreated ammonia water is fully mixed in the mixer 7 after being pressurized by the feed pump 4 and the alkali liquor after being pressurized by the alkali liquor tank 5 by the alkali liquor pump 6. After adjusting the pH value, it is passed through the feed preheater 8. After preheating, it enters the ammonia distillation tower 9. The ammonia water in the tower is drawn from the side line of the tower bottom pump 15 and enters the reboiler 16 for heating and returns to the ammonia distillation tower. The ammonia water and the ammonia heated by the reboiler undergo gas-liquid mass transfer in the tower. The ammonia gas at the top of the tower is condensed by the sub-contractor 10 and the top condenser 11 and then enters the gas-liquid separation tank 12. The claw vacuum pump 13 is evacuated to form the negative pressure of the ammonia distillation tower, and the pressure in the tower is kept stable by adjusting the pumping volume, and the ammonia gas extracted by the claw vacuum pump is used as the product outlet device. The condensed liquid ammonia water in the gas-liquid separation tank is pressurized by the ammonia water pump 14 and is discharged as an ammonia water product. The residue of the tower kettle is intermittently and regularly discharged through the residue pump 17. When the residue needs to be discharged, steam is introduced into the tower kettle steam coil, which can effectively prevent the tower kettle from scaling and block the pipeline.

Claims (6)

1. a coking residual ammonia water negative pressure ammonia steaming energy-saving device, it is characterized in that: comprise successively connected pretreatment device, coking residual ammonia water buffer tank, waste oil tank, lye tank, mixer, feed preheater, steam Ammonia tower, reboiler, sub-contractor, tower top condenser, gas-liquid separator, vacuum pump, feed pump, lye pump, ammonia water pump, tower bottom pump, residue pump and connecting pipeline; the coking residual ammonia water Negative pressure ammonia steaming energy-saving device, an lye mixer is installed on the pipeline before the remaining ammonia water enters the tower, the top of the ammonia steaming tower is directly connected with the sub-contractor, and is connected to the tower top condenser, gas-liquid separator and vacuum pump through the pipeline. The ammonia water pump is connected; the side line at the bottom of the ammonia distillation tower is connected with the bottom pump and the reboiler through the pipeline, and the bottom of the ammonia distillation tower is provided with an external heating coil, and the bottom of the tower is connected with the residue pump through the pipeline. 2. The energy-saving device for coking residual ammonia water negative pressure ammonia distillation as claimed in claim 1, characterized in that: the rectifying section in the ammonia distillation tower is provided with regular plate corrugated packing, and the stripping section is provided with a vertical sieve tray. 3. the coking residual ammonia water negative pressure ammonia steaming energy-saving device as claimed in claim 1 is characterized in that: in the described gas-liquid separator, non-condensable ammonia gas can be transported to the outside of the device through a vacuum pump, and liquid-phase ammonia can be transported to the outside of the device through a vacuum pump. The water pump is transported to the ammonia water storage tank. 4. The energy-saving device for coking residual ammonia water negative pressure steaming ammonia as claimed in claim 1, wherein the vacuum pump is a claw vacuum pump. 5. the coking residual ammonia water negative pressure ammonia steaming energy-saving device as claimed in claim 1 is characterized in that: the ammonia steaming waste water at the bottom of the ammonia steaming tower is drawn into two paths through the side line extraction of the tower bottom pump, and one path is the same as the reboiler tube path. The inlet is connected, and the other is connected to the shell side inlet of the feed preheater. After heat exchange with the remaining ammonia water, the ammonia distillation wastewater is sent to the biochemical treatment section. 6. the coking residual ammonia water negative pressure ammonia steaming energy-saving device as claimed in claim 1 is characterized in that: the bottom of the ammonia steaming tower is a conical head, and is accompanied by a steam coil, and the liquid at the bottom of the tower is intermittently discharged through a residue pump Steam is passed into the residue.

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