WO2020135136A1

WO2020135136A1 - Process and device for preparing sulfur pulp by performing vacuum evaporation treatment on coked sulfur foam

Info

Publication number: WO2020135136A1
Application number: PCT/CN2019/125765
Authority: WO
Inventors: 王嵩林; 张爽; 刘元德; 张素利; 赵国峰
Original assignee: 中冶焦耐(大连)工程技术有限公司
Priority date: 2018-12-27
Filing date: 2019-12-16
Publication date: 2020-07-02
Also published as: CN109534299A; CN109534299B

Abstract

Provided are a process and device for preparing sulfur pulp by performing vacuum evaporation treatment on coked sulfur foam. The process uses a vacuum evaporation technology and a low-grade heat source for performing heating treatment on the coked sulfur foam, so as to prepare sulfur pulp. The device comprises a vacuum evaporation tower (21), a circulating liquid heater (22), an ammonia steam cooler (23), a steam-liquid separator (24), a vacuum pump (25), a condensate circulating pump (26), a sulfur foam pump (27), and a sulfur slurry circulating pump (28). The process flow is simple, the construction investment is less, and the operation costs are low; development and utilization of low-grade waste heat resources as secondary energy are implemented, the energy utilization rate is increased, pollution of discharged heat to the environment is reduced, and the energy conservation and emission reduction effects are good; and the temperature of a low-grade heat source is lower than the melting point of sulfur, so that suspension sulfur in the sulfur foam is prevented from being attached to a heat exchange pipe due to melting and reducing the heat exchange efficiency.

Description

Process and device for preparing sulfur slurry by vacuum evaporation treatment of coking sulfur foam

Cross-reference of related applications

This disclosure requires the priority of the Chinese patent application filed on December 27, 2018, with the application number 201811608822.2, titled "Process and Device for Making Sulfur Slurry by Vacuum Evaporation of Coking Sulfur Foam", the entire contents of which are approved by References are incorporated in this disclosure.

Technical field

The present disclosure relates to the technical field of incineration of low-quality coking sulfur and desulfurization waste liquid for acid production, and in particular to a process and device for preparing sulfur slurry by vacuum evaporation of coking sulfur foam, which is suitable for the treatment of coke oven gas ammonia wet oxidative desulfurization process The resulting coking sulfur foam.

Background technique

Coking low-quality sulfur and desulfurization waste liquid incineration to produce acid technology is currently the most economical and environmentally friendly process for treating low-quality sulfur and desulfurization sub-salt waste liquid produced by the ammonia wet oxidative desulfurization process of coke oven gas. The pretreatment process in this process uses sulfur foam as the initial raw material, and the sulfur slurry is prepared by centrifugation, concentration and condensation, and then sent to an incinerator for incineration.

In the prior art, the process flow of the pretreatment process is shown in Figure 1. The sulfur foam at the top of the regeneration tower flows to the foam tank 1 and is sent to the horizontal centrifuge 4 through the foam pump 2 to separate the suspended sulfur in the sulfur foam . After solid-liquid two-phase centrifugal separation, the separated suspended sulfur is converted into sulfur paste, which flows to the slurry tank 6 by gravity and sulfur slurry flushing; the separated filtrate (still containing about 1g/L suspended sulfur) flows to the filtrate tank 5. The filtrate in the filtrate tank 5 is drawn by the filtrate pump 3, and a part (equivalent to the amount of desulfurization waste liquid) is sent to the concentration tower 11 for concentration, and the rest is sent back to the desulfurization tower for desulfurization; and, the slurry tank 6 is provided with a mechanical agitator, which will The sulfur paste and the desulfurized secondary salt concentrate from the concentration tower are forcibly mixed uniformly to obtain a sulfur slurry. The sulfur slurry in the slurry tank 6 can be directly sent to the incinerator for incineration for acid production through the slurry transfer pump 8, or it can be sent to the slurry storage tank buffer first, and then sent to the incinerator for incineration for acid production.

The concentration device of the filtrate is composed of a concentration tower 11, a concentrated liquid heater 9 and a concentrated liquid circulation pump 10, which is a forced circulation external heating atmospheric pressure evaporation device. The filtrate that needs to be concentrated is directly added to the circulating liquid pipeline before the concentrated liquid heater 9, heated by low-pressure steam, and then sent to the concentrated tower 11 for evaporation. The operating temperature of the circulating liquid at the bottom of the concentration tower 11 is controlled at 120-125°C. The extra circulating liquid (ie, concentrated liquid) is sent to the slurry tank 6 through the concentrated liquid circulating pump 10, and the steam containing NH ₃ steamed at the top of the tower is sent The condensation tower 12 condenses.

The NH ₃ -containing steam condensation device at the top of the concentration tower 12 is composed of a condensation tower 12, a condensate cooler 13 and a condensate circulation pump 14, which is a forced circulation external cooling atmospheric pressure condensing device. The steam containing NH ₃ steamed from the top of the concentrating tower 11 is sent to the middle of the condensing tower 12 and is condensed in countercurrent contact with the circulating liquid sprayed from the top of the tower. The operating temperature of the circulating liquid at the bottom of the condensing tower 12 is controlled at 40-60°C. After cooling by circulating water, the condensing tower 12 is sent to the top of the condensing tower for circulating spraying. When used, it can also be sent to an ammonia distillation tower to steam ammonia; and, the non-condensable vapor at the top of the condensation tower 12 is sent to the negative pressure gas pipeline in front of the blower.

The disadvantage of this pretreatment process is the long process flow, large investment, and high operating cost; at the same time, due to the use of steam heating, the wall temperature of the heat exchange tube is close to the steam temperature, and the steam temperature is higher than the melting point of sulfur (melting point temperature 114.5℃) , It is easy to cause the remaining suspended sulfur in the concentrated circulating liquid to melt and attach to the wall of the tube, which greatly reduces the heat exchange efficiency.

Summary of the invention

The present disclosure provides a process and a device for preparing a sulfur slurry by vacuum evaporation of coking sulfur foam. It uses vacuum evaporation technology and a low-grade heat source to heat and treat the coking sulfur foam to produce sulfur slurry. It is a construction investment with low investment and operating cost. Low process and equipment.

In order to achieve at least the above objects, on the one hand, the present disclosure provides a process for preparing a sulfur slurry by vacuum evaporation of coking sulfur foam, which uses vacuum evaporation technology and a low-grade heat source to heat the coking sulfur foam to prepare sulfur slurry, which includes the following steps:

The sulfur foam at the top of the regeneration tower of the desulfurization unit is pressurized by the sulfur foam pump, and then directly sent to the sulfur slurry circulation liquid pipeline in front of the circulation liquid heater. After being heated and heated by a low-grade heat source, it is sent to the vacuum evaporation tower for evaporation and evaporation. Excess water and a small amount of ammonia, the unevaporated component is sulfur slurry;

The sulfur slurry at the bottom of the vacuum evaporation tower is sent out in two ways through the sulfur slurry circulation pump: one way is to mix the sulfur slurry and sulfur foam and send it to the circulating liquid heater for heating, then enter the vacuum evaporation tower to evaporate, and the other way will produce The sulfur slurry is directly sent to the incinerator for incineration or to the slurry storage tank buffer;

The ammonia vapor evaporated at the top of the vacuum evaporation tower enters the ammonia vapor cooler for partial condensation. The released heat is transferred by external circulating cooling water. The condensed vapor-liquid mixture enters the vapor-liquid separator for vapor-liquid separation. The separated condensate , It is sent out in two ways through the condensate circulation pump, one way sends the condensate back to the ammonia vapor cooler for spraying, scours and dissolves the ammonium salt and other impurities attached to the outer wall of the heat exchange tube, and the other way sends the condensate generated per unit time The desulfurization unit is used as make-up water; and

The non-condensed non-condensable steam is sucked by the vacuum pump to generate negative pressure to maintain the stability of the vacuum degree of the vacuum evaporation tower. The pumped non-condensable steam is heated and boosted by the compression action of the vacuum pump and sent to the desulfurization unit Gas pipeline in front of the pre-cooling tower.

In one or more embodiments, the low-grade heat source is selected from hot lean oil, ammonia-distilled wastewater, recycled ammonia, or acid absorption.

In one or more embodiments, the hot lean oil is used as a low-grade heat source after the crude benzene distillation unit lean rich oil heat exchanger is used during the overhaul of the acid production unit.

In one or more embodiments, the vacuum degree of the vacuum evaporation tower is determined according to the temperature of the low-grade heat source.

In one or more embodiments, the vacuum degree of the vacuum evaporation tower is controlled at 70-89KPa, and the corresponding operating temperature is 50-70°C.

In one or more embodiments, a mechanical stirrer is provided in the vacuum evaporation tower to perform forced stirring and mixing.

In one or more embodiments, the non-condensable vapors are ammonia vapor and non-condensable vapors.

In one or more embodiments, the pumped non-condensable vapor is heated and boosted by the compression action of the vacuum pump, and is not discharged after being sent to the gas pipeline in front of the pre-cooling tower of the desulfurization unit.

In one or more embodiments, in the circulating fluid heater, the mixed circulating fluid is heated to 65-75°C and the low-grade heat source is cooled to 65-70°C.

In one or more embodiments, in the ammonia vapor cooler, the temperature of the ammonia vapor is cooled to 35-40°C, and the temperature of the circulating cooling water is heated to 40-45°C.

Another aspect of the present disclosure provides a device used in a process for preparing a sulfur slurry by vacuum evaporating coking sulfur foam as provided by the present disclosure, which includes a vacuum evaporation tower, a circulating liquid heater, an ammonia vapor cooler, a vapor-liquid separator, Vacuum pump, condensate circulation pump, sulfur foam pump, sulfur slurry circulation pump, the sulfur slurry outlet at the bottom of the vacuum evaporation tower is connected to the inlet of the sulfur slurry circulation pump; the outlet of the sulfur slurry circulation pump is divided into two channels, and one outlet is connected to the circulating liquid heater Sulfur slurry inlet, another outlet exports sulfur slurry; the sulfur slurry outlet of the circulating liquid heater is connected to the sulfur slurry inlet of the vacuum evaporation tower; the sulfur foam pump inlet is connected to the sulfur foam input pipe, and the sulfur foam pump outlet is connected to the circulating liquid heating The sulfur slurry inlet of the separator; the ammonia vapor outlet at the top of the vacuum evaporation tower is connected to an inlet of the ammonia gas cooler, and an outlet of the ammonia gas cooler is connected to the inlet of the vapor-liquid separator; the outlet of the vapor-liquid separator is divided into two channels. One outlet is connected to the inlet of the vacuum pump, and the other outlet is connected to the inlet of the condensate circulation pump;

The outlet of the condensate circulation pump is divided into two channels, one outlet is connected to an ammonia gas cooler, and the other outlet outputs condensate; and, the outlet of the vacuum pump outputs non-condensable vapor, and a mechanical agitator is provided in the vacuum evaporation tower.

In one or more embodiments, the ammonia vapor cooler uses a shell and tube heat exchanger.

In one or more embodiments, the shell of the ammonia vapor cooler takes ammonia vapor, the tube of the ammonia vapor cooler takes circulating cooling water, and the condensate returned from the condensate circulation pump passes into the shell of the ammonia vapor cooler Cheng, used to scour and dissolve a small amount of ammonium salts and other impurities attached to the outer wall of the heat exchange tube.

In one or more embodiments, the circulating liquid heater uses a shell and tube heat exchanger.

In one or more embodiments, the tube side of the circulating liquid heater takes the sulfur slurry, and the shell side takes the low-grade heat source.

The beneficial effects achieved by the process and device for preparing a sulfur slurry by vacuum evaporation treatment of coking sulfur foam provided by the present disclosure include, for example:

1) The process flow is simple, the construction investment is low, and the running cost is low;

2) The development and utilization of low-grade waste heat resources as secondary energy has been realized, which has improved the energy utilization rate, reduced the pollution of the heat exhaust to the environment, and has good energy saving and emission reduction effects; and

3) The temperature of the low-grade heat source is lower than the melting point of sulfur, which prevents the suspended sulfur in the sulfur foam from melting and adhering to the heat exchange tube to reduce the heat exchange efficiency.

BRIEF DESCRIPTION

Figure 1 is a schematic diagram of the process flow of the pretreatment process in the prior art coking low-quality sulfur and desulfurization waste liquid incineration technology;

Figure 1: 1-foam tank, 2-foam pump, 3-filtrate pump, 4-centrifuge, 5-filtrate tank, 6-slurry tank, 7-slurry rinse pump, 8-slurry transfer pump, 9-concentrate Heater, 10-concentrate circulation pump, 11-concentration tower, 12-condensation tower, 13-condensate cooler, 14-condensate circulation pump.

2 is a schematic flowchart of a process for preparing a sulfur slurry by vacuum evaporation of coking sulfur foam provided by the present disclosure;

Figure 2: 21-vacuum evaporation tower, 22-circulating liquid heater, 23-ammonia vapor cooler, 24-vapor-liquid separator, 25-vacuum pump, 26-condensate circulating pump, 27-sulfur foam pump, 28- Sulfur slurry circulation pump.

detailed description

The content of the present disclosure will be further described in detail below in conjunction with specific embodiments, but it should not be construed that the scope of the present disclosure is limited to the following examples. Without departing from the above technical ideas of the present disclosure, various replacements or changes based on common technical knowledge in the art and common technical means should be included within the scope of the present disclosure.

As shown in Figure 2, the process of preparing a sulfur slurry by vacuum evaporation of coking sulfur foam, which uses vacuum evaporation technology and low-grade heat source heating treatment of coking sulfur foam to prepare sulfur slurry, includes the following steps:

The sulfur foam at the top of the regeneration tower of the desulfurization unit is pressurized by the sulfur foam pump 27, and then directly sent to the sulfur slurry circulating liquid pipeline in front of the circulating liquid heater 22. After being heated and heated by a low-grade heat source, it is sent to the vacuum evaporation tower 21 for evaporation , The excess water and a small amount of ammonia are distilled off, and the unevaporated component is sulfur slurry;

The sulfur slurry at the bottom of the vacuum evaporation tower 21 is sent out in two ways through the sulfur slurry circulation pump 28: one way the sulfur slurry and sulfur foam are mixed and sent to the circulating liquid heater 22 for heating, then enter the vacuum evaporation tower 21 for evaporation, and the other way the unit The sulfur slurry generated within the time is directly sent to the incinerator for incineration or to the slurry storage tank buffer; in order to prevent the precipitation of suspended sulfur in the vacuum evaporation tower 21 and the excessive concentration of the local concentration causing the precipitation of ammonium salt crystals, a mechanical stirrer is set to perform forced stirring and mixing;

The ammonia-containing steam distilled from the top of the vacuum evaporation tower 21 is ammonia steam, which enters the ammonia vapor cooler 23 for partial condensation, the released heat is transferred by external circulating cooling water, and the condensed vapor-liquid mixture enters the vapor-liquid separator 24 for Vapor-liquid separation, the separated condensate is sent out in two ways through the condensate circulation pump 26, and the condensate is sent back to the ammonia vapor cooler 23 for spraying all the way, washing and dissolving a small amount of ammonium salt and other impurities attached to the outer wall of the heat exchange tube , Another way to send the condensate produced per unit time back to the desulfurization unit for make up water; and

Ammonia vapor and non-condensable gas that are not condensed, that is, non-condensable vapor, are sucked by the vacuum pump 25 to generate negative pressure to keep the vacuum degree of the vacuum evaporation tower 21 stable, and the non-condensable vapor that is sucked is passed through the vacuum pump 25 After the temperature is increased by compression, it is sent to the gas pipeline in front of the pre-cooling tower of the desulfurization unit, and is not discharged outside.

The low-grade heat source is selected from hot lean oil, steamed ammonia wastewater, recycled ammonia water or acid absorption. The vacuum required for vacuum evaporation is generated by the vacuum pump 25, and the vacuum intensity is reasonably determined according to the temperature of the low-grade heat source.

The vacuum degree of the vacuum evaporation tower 1 is controlled at 70-89KPa, such as 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89KPa, the corresponding operating temperature is 50-70 ℃, such as 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70 ℃.

The device used in the process of preparing the sulfur slurry by the vacuum evaporation treatment of coking sulfur foam is a forced circulation external heating vacuum evaporation device, which includes a vacuum evaporation tower 21, a circulating liquid heater 22, an ammonia vapor cooler 23, a steam The liquid separator 24, vacuum pump 25, condensate circulation pump 26, sulfur foam pump 27, sulfur slurry circulation pump 28, the sulfur slurry outlet at the bottom of the vacuum evaporation tower 21 is connected to the inlet of the sulfur slurry circulation pump 28; the outlet of the sulfur slurry circulation pump 28 Divided into two channels, one outlet is connected to the sulfur slurry inlet of the circulating liquid heater 22, and the other outlet outputs sulfur slurry outward; the sulfur slurry outlet of the circulating liquid heater 22 is connected to the sulfur slurry inlet of the vacuum evaporation tower 21; the sulfur foam pump 27 The inlet is connected to the sulfur foam input pipe, and the outlet of the sulfur foam pump 27 is connected to the sulfur slurry inlet of the circulating liquid heater 22; the ammonia vapor outlet at the top of the vacuum evaporation tower 21 is connected to an inlet of the ammonia gas cooler 23 and an ammonia gas cooler 23 The outlet is connected to the inlet of the vapor-liquid separator 24; the outlet of the vapor-liquid separator 24 is divided into two channels, one outlet is connected to the inlet of the vacuum pump 25, and the other outlet is connected to the inlet of the condensate circulation pump 26; the outlet of the condensate circulation pump 26 Divided into two channels, one outlet is connected to an ammonia gas cooler 23, and the other outlet outputs condensate; and, the outlet of the vacuum pump 25 outputs non-condensable vapor, and a mechanical agitator is provided in the vacuum evaporation tower 21.

The ammonia vapor cooler 23 uses a shell and tube heat exchanger. Ammonia vapor cooler 23 uses ammonia vapor in the shell side, and ammonia vapor cooler 23 uses circulating cooling water in the tube side. The condensate returned from condensate circulation pump 26 passes into the ammonia vapor cooler 23 shell side for flushing ammonia A small amount of ammonium salt and other impurities attached to the shell side of the steam cooler 23 (ie, the outer wall of the heat exchange tube).

The circulating liquid heater 22 uses a shell-and-tube heat exchanger. The tube side of the circulating liquid heater 22 goes to the sulfur slurry, and the shell side of the circulating liquid heater 22 goes to the low-grade heat source.

Example 1

The sulfur foam at the top of the regeneration tower of the desulfurization unit is pressurized by the sulfur foam pump 27, and then directly sent to the sulfur slurry circulating liquid pipeline in front of the circulating liquid heater 22. After being heated and heated by the circulating ammonia water, it is sent to the vacuum evaporation tower 21 for evaporation. Distilling excess water will also distill a small amount of ammonia. The unevaporated component is the sulfur slurry. In the circulating liquid heater 22, the temperature of the mixed circulating liquid is heated from 50-55°C to 65°C, and the temperature of the circulating ammonia water is cooled from 75-80°C to 65°C. The vacuum degree of the vacuum evaporation tower 21 is controlled at 85.6 KPa, and the corresponding operating temperature is 55°C. In order to prevent the precipitation of suspended sulfur in the vacuum evaporation tower 21 and the excessively high local concentration resulting in the precipitation of ammonium salt crystals, a mechanical stirrer is set to perform forced stirring and mixing.

The sulfur slurry at the bottom of the vacuum evaporation tower 21 is sent out in two ways through the sulfur slurry circulation pump 28: the sulfur slurry and sulfur foam are mixed in one way and sent to the circulating liquid heater 22 for heating, and then enter the vacuum evaporation tower 21 for evaporation, and further prevent the bottom Suspended sulfur precipitation; another way is to send the sulfur slurry produced in unit time directly to the incinerator for incineration or to the slurry storage tank buffer.

The ammonia-containing steam evaporated at the top of the vacuum evaporation tower 21 is ammonia vapor, and enters the ammonia vapor cooler 23 for partial condensation, and the released heat is transferred by external circulating cooling water. In the ammonia vapor cooler 23, the ammonia vapor temperature is cooled from 55-60°C to 35-40°C, the ammonia vapor partially condenses, and the circulating cooling water temperature is heated from 32°C to 40-45°C.

The condensed vapor-liquid mixture enters the vapor-liquid separator 24 for vapor-liquid separation. The separated condensate is sent out in two ways through the condensate circulation pump 26, and the condensate is sent back to the ammonia vapor cooler 23 for spraying to dissolve a small amount of ammonium salt and other impurities attached to the outer wall of the heat exchange tube. Send the condensate produced per unit time back to the desulfurization unit for make-up water. Ammonia vapor and non-condensable gas that are not condensed, that is, non-condensable vapor, are sucked by the vacuum pump 25 to generate negative pressure to keep the vacuum degree of the vacuum evaporation tower 21 stable. The sucked non-condensable steam is heated and boosted by the compression action of the vacuum pump 25, and then sent to the gas pipeline in front of the pre-cooling tower of the desulfurization unit, without being discharged.

Example 2

The sulfur foam at the top of the regeneration tower of the desulfurization unit is pressurized by the sulfur foam pump 27, and then directly sent to the sulfur slurry circulating liquid pipeline in front of the circulating liquid heater 22. After being heated by the absorption acid, it is sent to the vacuum evaporation tower 21 for evaporation. Distilling excess water will also distill a small amount of ammonia. The unevaporated component is the sulfur slurry. In the circulating liquid heater 22, the temperature of the mixed circulating liquid is heated from 55-60°C to 75°C, and the temperature of the absorption acid is cooled from 90-100°C to 70°C. The vacuum degree of the vacuum evaporation tower 21 is controlled at 81.4 KPa, and the corresponding operating temperature is 60°C. In order to prevent the precipitation of suspended sulfur in the vacuum evaporation tower 21 and the excessively high local concentration resulting in the precipitation of ammonium salt crystals, a mechanical stirrer is set to perform forced stirring and mixing. During the maintenance of the acid production unit, the hot lean oil after the lean rich oil heat exchanger of the crude benzene distillation unit can be used as a low-grade heat source instead of absorbing acid.

The ammonia-containing steam evaporated at the top of the vacuum evaporation tower 21 is ammonia vapor, and enters the ammonia vapor cooler 23 for partial condensation, and the released heat is transferred by external circulating cooling water. In the ammonia vapor cooler 23, the ammonia vapor temperature is cooled from 60-65°C to 35°C, the ammonia vapor is partially condensed, and the circulating cooling water temperature is heated from 32°C to 40-45°C.

Industrial applicability

The process and device for preparing sulfur slurry by vacuum evaporation treatment of coking sulfur foam can be used in industry in batches, the process is simple, the construction investment is low, the operating cost is low, and the development of low-grade waste heat resources as secondary energy is realized And utilization, which improves energy utilization, reduces pollution of heat exhaust to the environment, and has good energy-saving and emission-reduction effects, and because the temperature of the low-grade heat source is lower than the melting point of sulfur, it prevents the suspended sulfur in the sulfur foam from adhering to the heat exchange tube due to melting And reduce the heat exchange efficiency.

Claims

Vacuum evaporation process of coking sulfur foam to prepare sulfur slurry. It uses vacuum evaporation technology and low-grade heat source to heat and treat coking sulfur foam to produce sulfur slurry. The specific methods are as follows:

The sulfur foam at the top of the regeneration tower of the desulfurization unit is pressurized by the sulfur foam pump, and then directly sent to the sulfur slurry circulation liquid pipeline in front of the circulation liquid heater. After being heated and heated by a low-grade heat source, it is sent to the vacuum evaporation tower for evaporation and evaporation. Excess water and a small amount of ammonia, the unevaporated component is sulfur slurry;

The sulfur slurry at the bottom of the vacuum evaporation tower is sent out in two ways through the sulfur slurry circulation pump: one way is to mix the sulfur slurry and sulfur foam and send it to the circulating liquid heater for heating, then enter the vacuum evaporation tower to evaporate, and the other way will produce The sulfur slurry is directly sent to the incinerator for incineration or to the slurry storage tank buffer;

The ammonia vapor evaporated at the top of the vacuum evaporation tower enters the ammonia vapor cooler for partial condensation. The released heat is transferred by external circulating cooling water. The condensed vapor-liquid mixture enters the vapor-liquid separator for vapor-liquid separation. The separated condensate , It is sent out in two ways through the condensate circulation pump, one way sends the condensate back to the ammonia vapor cooler for spraying, scours and dissolves the ammonium salt and other impurities attached to the outer wall of the heat exchange tube, and the other way sends the condensate generated per unit time The desulfurization unit is used as make-up water; and

The non-condensed non-condensable steam is sucked by the vacuum pump to generate negative pressure to maintain the stability of the vacuum degree of the vacuum evaporation tower. The pumped non-condensable steam is heated and boosted by the compression action of the vacuum pump and sent to the desulfurization unit Gas pipeline in front of the pre-cooling tower.
The process for preparing sulfur slurry by vacuum evaporating coking sulfur foam according to claim 1, wherein the low-grade heat source is selected from hot lean oil, steamed ammonia wastewater, recycled ammonia water or acid absorption.
The process for preparing sulfur slurry by coking sulfur foam by vacuum evaporation according to claim 2, wherein the hot lean oil is used as a low-grade heat source after using the crude benzene distillation unit lean rich heat exchanger during the overhaul of the acid production unit.
The process for preparing sulfur slurry by coking sulfur foam with vacuum evaporation according to any one of claims 1 to 3, wherein the vacuum degree of the vacuum evaporation tower is determined according to the temperature of the low-grade heat source.
According to any one of claims 1 to 4, a process for preparing sulfur slurry by vacuum evaporating coking sulfur foam, wherein the vacuum degree of the vacuum evaporation tower is controlled at 70-89KPa, and the corresponding operating temperature is 50-70°C.
The process for preparing sulfur slurry by coking sulfur foam by vacuum evaporation according to any one of claims 1 to 5, wherein a mechanical stirrer is provided in the vacuum evaporation tower to perform forced stirring and mixing.
The process for preparing sulfur slurry by vacuum evaporating coking sulfur foam according to any one of claims 1 to 6, wherein the non-condensable vapor is ammonia vapor and non-condensable vapor.
The process for preparing sulfur slurry by vacuum evaporating coking sulfur foam according to any one of claims 1 to 7, wherein the sucked non-condensable vapor is heated and boosted by the compression action of the vacuum pump before being fed into the desulfurization unit After the gas pipeline in front of the cooling tower, it will not be discharged.
The process for preparing sulfur slurry by vacuum evaporating coking sulfur foam according to any one of claims 1 to 8, wherein in the circulating liquid heater, the mixed circulating liquid is heated to 65-75°C, and the low The grade heat source is cooled to 65-70℃.
The process for preparing a sulfur slurry by vacuum evaporating coking sulfur foam according to any one of claims 1 to 9, wherein in the ammonia vapor cooler, the temperature of the ammonia vapor is cooled to 35-40°C and the circulation is cooled The water temperature is heated to 40-45°C.
The device used in the process of preparing a sulfur slurry by vacuum evaporation of coking sulfur foam according to any one of claims 1 to 10, which includes a vacuum evaporation tower, a circulating liquid heater, an ammonia vapor cooler, a vapor-liquid separator, Vacuum pump, condensate circulation pump, sulfur foam pump, sulfur slurry circulation pump,

The sulfur slurry outlet at the bottom of the vacuum evaporation tower is connected to the inlet of the sulfur slurry circulation pump;

The outlet of the sulfur slurry circulation pump is divided into two channels, one outlet is connected to the sulfur slurry inlet of the circulating liquid heater, and the other outlet outputs sulfur slurry outward;

The sulfur slurry outlet of the circulating liquid heater is connected to the sulfur slurry inlet of the vacuum evaporation tower;

The inlet of the sulfur foam pump is connected to the sulfur foam input pipeline, and the outlet of the sulfur foam pump is connected to the inlet of the sulfur slurry of the circulating liquid heater;

The ammonia vapor outlet at the top of the vacuum evaporation tower is connected to an inlet of the ammonia gas cooler, and an outlet of the ammonia gas cooler is connected to the inlet of the vapor-liquid separator;

The outlet of the vapor-liquid separator is divided into two channels, one outlet is connected to the inlet of the vacuum pump, and the other outlet is connected to the inlet of the condensate circulation pump;

The outlet of the condensate circulation pump is divided into two channels, one outlet is connected to an ammonia gas cooler, and the other outlet outputs condensate; and,

The outlet of the vacuum pump outputs non-condensable vapor, and a mechanical stirrer is provided in the vacuum evaporation tower.
The apparatus used in the process for preparing a sulfur slurry by vacuum evaporation of coking sulfur foam according to claim 11, wherein the ammonia vapor cooler is a shell-and-tube heat exchanger.
The device used in the process for preparing a sulfur slurry by vacuum evaporation of coking sulfur foam according to claim 11 or 12, wherein the ammonia vapor cooler uses ammonia vapor in the shell side and the ammonia vapor cooler uses circular cooling water in the tube side. The condensate returned from the condensate circulation pump is passed into the shell side of the ammonia vapor cooler to wash away and dissolve a small amount of ammonium salts and other impurities attached to the outer wall of the heat exchange tube.
The apparatus used in the process of preparing a sulfur slurry by vacuum evaporation of coking sulfur foam according to any one of claims 11 to 13, wherein the circulating liquid heater uses a shell and tube heat exchanger.
The device used in the process of preparing a sulfur slurry by vacuum evaporation of coking sulfur foam according to any one of claims 11 to 14, wherein the tube side of the circulating liquid heater goes to the sulfur slurry, and the shell side goes to a low-grade heat source .