Device for improving yield of sulfur trioxide

Abstract

A device for improving the yield of sulfur trioxide comprises an absorption tower, a sulfur trioxide evaporator, a heat exchanger, a steam heater, a plurality of self-control instrument interlocks and the like. SO3-containing flue gas enters the absorption tower, SO3 in the flue gas is circularly absorbed by fuming sulphuric acid, the concentration of the fuming sulphuric acid is increased, the fuming sulphuric acid is pressurized and sequentially fed into the heat exchanger, the steam heater and the sulfur trioxide evaporator, the fuming sulphuric acid is heated to the boiling point, SO3 is evaporated and escaped from the fuming sulphuric acid to prepare high-purity SO3, and low-concentration fuming sulphuric acid flows back to the absorption tower and circularly absorbs SO3 in the flue gas. When the device is in 50% load production operation, the heat of high-temperature flue gas of a heating medium of the sulfur trioxide evaporator is correspondingly low, the temperature rise of fuming sulfuric acid in the sulfur trioxide evaporator is reduced, the SO3 evaporation efficiency is reduced, the temperature of the fuming sulfuric acid entering the sulfur trioxide evaporator is increased through steam heating by using a steam heater, and the SO3 evaporation efficiency is improved; and through interlocking control of a self-control electric instrument, the device operates automatically, and the safety and stability are high.

Description

TECHNICAL FIELD

[0001] The utility model relates to high -purity liquid sulfur trioxide production device technical field, specifically, relate to a device of improving sulfur trioxide yield. BACKGROUND

[0002] High -purity liquid sulfur trioxide is the only raw material of production electronic grade sulfuric acid, and electronic grade sulfuric acid is mainly used for the cleaning of silicon wafer, photoetching, the corrosion and cleaning of printed circuit board, and belongs to indispensable key basic chemical reagent in semiconductor industry.

[0003] Because electronic grade sulfuric acid customer development needs to pass through many rounds of test, product development cycle is long, and the demand is small during the early customer development, and the sulfur trioxide output is correspondingly low, and the device production load is low. High -purity liquid sulfur trioxide production process mainly relies on sulfur-burning sulfuric acid device, mainly utilizes the SO3 flue gas of converter three sections and four sections, and in the fuming sulfuric acid absorption tower, the SO3 flue gas of three sections is absorbed by low -concentration fuming sulfuric acid to improve the acid concentration, and in the sulfur trioxide evaporator, high -temperature SO3 flue gas from four sections is used to heat high -concentration fuming sulfuric acid to prepare sulfur trioxide. When the device is normally full load production, the liquid sulfur trioxide yield can reach 74%, when the device production load is 50%, because the high -temperature flue gas heat from the converter four sections reduces, the evaporation efficiency of sulfur trioxide evaporator reduces, and the highest high -purity liquid sulfur trioxide yield can only reach 46%, and the industrial sulfuric acid output correspondingly increases, resulting in the reduction of the overall production economic benefit of the device. UTILITY MODEL CONTENT

[0004] In view of the low evaporation efficiency of sulfur trioxide evaporator, the low high -purity liquid sulfur trioxide yield technical problem in the background art, the utility model provides a device of improving sulfur trioxide yield.

[0005] In order to solve the above problems, the present application is realized by the following technical scheme:

[0006] A device for improving the yield of sulfur trioxide, comprising an absorption tower, the absorption tower is sequentially communicated with a feed pump, a primary pump and a secondary pump on the pump tank at the bottom of the absorption tower;

[0007] The outlet of the feed pump is communicated with the inlet of the shell side of the heat exchanger, the outlet pipe of the shell side of the heat exchanger is provided with a remote thermometer two, the bypass pipe of the shell side material of the steam heat exchanger and the inlet pipe of the shell side of the heat exchanger are connected in parallel with the inlet pipe of the acid inlet pipe, and the acid inlet pipe is also provided with an acid inlet valve, the bypass pipe of the shell side material of the steam heat exchanger and the outlet pipe of the shell side of the steam heater are connected in parallel with the inlet pipe of the sulfur trioxide evaporator, and the sulfur trioxide evaporator is connected with the inlet pipe of the heat exchanger through the pipe side liquid outlet pipe and the remote thermometer four.

[0008] The absorption tower is provided with a primary packing layer and a secondary packing layer, a buffer chamber is arranged between the top of the primary packing layer and the bottom of the secondary packing layer, the buffer chamber is communicated with the inlet of an outlet pipe, and the outlet of the outlet pipe is communicated with the bottom of the absorption tower and arranged below the primary packing layer.

[0009] The outlet pipe of the primary pump is further provided with a primary cooler and a primary temperature control valve in parallel, the inlet pipe of the primary temperature control valve and the inlet pipe of the shell side of the primary cooler are in parallel, the outlet pipe of the primary temperature control valve and the outlet pipe of the shell side of the primary cooler are in parallel, and a primary thermometer is arranged at the side of the junction of the parallel outlet pipes.

[0010] The outlet pipe of the secondary pump is further provided with a secondary cooler and a secondary temperature control valve in parallel, the inlet pipe of the secondary temperature control valve and the inlet pipe of the shell side of the secondary cooler are in parallel, the outlet pipe of the secondary temperature control valve and the outlet pipe of the shell side of the secondary cooler are in parallel, and a secondary thermometer is arranged at the side of the junction of the parallel outlet pipes.

[0011] The inlet pipe of the pipe side of the sulfur trioxide evaporator is further provided with a remote thermometer three, the top of the sulfur trioxide evaporator is communicated with the inlet of a fan through a pipe side gas outlet pipe and a remote pressure gauge, the outlet of the fan is communicated with the rectifying tower.

[0012] The inlet pipe of the absorption tower is arranged below the primary packing layer, and the top end of the absorption tower is further provided with a tail gas pipe connected with the sulfur-burning sulfuric acid absorption tower.

[0013] The inlet pipe of the pipe side of the steam heater is connected with a steam pipe, a steam regulating valve is arranged on the steam pipe, the outlet pipe of the pipe side of the steam heater is connected with a condensed water pipe, a trap valve and a remote pH meter are arranged on the condensed water pipe, the outlet pipe of the shell side of the steam heater is communicated with the inlet pipe of the pipe side of the sulfur trioxide evaporator through a bypass pipe provided with a bypass valve, and an acid outlet valve is further arranged on the outlet pipe of the shell side of the steam heater.

[0014] The outlet pipe of the pipe side of the heat exchanger is further provided with a remote thermometer five and a remote acid return instrument, and the outlet of the pipe side of the heat exchanger is communicated with the secondary pump separation tank in the absorption tower.

[0015] The liquid level end of the pump between the feed pump and the primary pump is separated by a partition plate, the liquid level end of the pump between the primary pump and the secondary pump is separated by a partition plate, one side of the bottom of the primary pump is communicated with the bottom of the feed pump, the other side of the bottom of the primary pump is communicated with the bottom of the secondary pump, the outlet pipe of the primary pump is communicated with the inlet pipe of the buffer chamber of the absorption tower, the outlet pipe of the secondary pump is communicated with the inlet of the chamber at the top of the secondary packing layer in the absorption tower, and the outlet of the feed pump is communicated with the inlet of the shell side of the heat exchanger through a pipeline and a remote upper acid instrument and a remote thermometer one.

[0016] The inlet pipe of the shell side of the sulfur trioxide evaporator is communicated with a high-temperature flue gas pipe, and the outlet pipe of the shell side of the sulfur trioxide evaporator is communicated with a low-temperature flue gas pipe through a high-temperature regulating valve.

[0017] Preferably, the tube side inlet of the steam heater is connected to steam, and the fluid in the tube side and the shell side flows in the same direction for heat exchange.

[0018] Preferably, the shell side inlet of the sulfur trioxide evaporator is connected to high-temperature flue gas, and the fluid in the shell side and the tube side flows in opposite directions for heat exchange.

[0019] Preferably, the tube side inlet of the primary cooler is connected to circulating cooling water, and the fluid in the tube side and the shell side flows in opposite directions for heat exchange.

[0020] Preferably, the tube side inlet of the secondary cooler is connected to circulating cooling water, and the fluid in the tube side and the shell side flows in opposite directions for heat exchange.

[0021] Preferably, the material inlet pipe of the absorption tower is connected to high-concentration sulfur trioxide flue gas.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] 1. The present application adds a steam heater. When the device is running at half load, the steam heater is used. By adjusting the opening degree of the steam regulating valve, the temperature of the fuming sulfuric acid entering the sulfur trioxide evaporator is increased, the evaporation rate of the fuming sulfuric acid is increased, the yield of liquid sulfur trioxide is improved, and the economic benefit of the device is improved.

[0024] 2. The feed fan is connected to the top gas phase port of the sulfur trioxide evaporator, and frequency control is adopted to ensure that the top gas phase space of the sulfur trioxide evaporator is at a slight positive pressure, the partial pressure of sulfur trioxide on the surface of the fuming sulfuric acid is reduced, the flashing rate of the fuming sulfuric acid is increased, and the yield of liquid sulfur trioxide is improved.

[0025] 3. The pump tank integrated absorption tower is reasonably designed. High-concentration high-temperature fuming sulfuric acid and low-concentration low-temperature fuming sulfuric acid are effectively isolated. At the same time, the process route is reasonably optimized. The high-concentration high-temperature fuming sulfuric acid is sent to the evaporation device, and the low-concentration low-temperature fuming sulfuric acid is sent to the absorption device. The sulfur trioxide evaporation efficiency and the absorption rate of sulfur trioxide in the flue gas by the fuming sulfuric acid can be effectively improved, the land is saved, and the sulfur trioxide yield is improved.

[0026] 4. The present application designs a more advanced safety interlocking system. When the remote pH meter reaches the interlocking alarm value, the interlocking is triggered, the bypass valve is immediately opened, the steam regulating valve, the acid inlet valve and the acid outlet valve are closed, the equipment is prevented from being corroded after the steam heater leaks, and the safe and stable operation of the device is ensured. When the remote acid return instrument reaches the interlocking alarm value, the interlocking is triggered, the steam regulating valve and the high-temperature regulating valve are immediately closed, the fuming sulfuric acid in the sulfur trioxide evaporator is stopped from continuing to evaporate, the equipment is prevented from being corroded by low-concentration fuming sulfuric acid, and the intrinsic safety of the device is ensured.

[0027] 5、The utility model discloses a plurality of electrical instrument control systems are added, such as all machine pump and fan adopt frequency conversion motor control, reduce power consumption, the temperature control valve is added to the first cooler, the second cooler, realizes the self -control adjustment of the tower fuming sulfuric acid temperature of going in, the fuming sulfuric acid temperature of going in three sulfur trioxide evaporator is adjusted to the self -control adjustment of steam regulating valve, the fuming sulfuric acid temperature of going out three sulfur trioxide evaporator is adjusted to the self -control adjustment of high -temperature regulating valve, when guaranteeing the accurate control of production process, can realize the automatic operation of device, reduce manual intervention, ensure the device intrinsic safety.

[0028] 6、Through the innovation on technological process, the automatic device of the application can improve liquid sulfur trioxide yield under half load production, add steam heater before fuming sulfuric acid enters sulfur trioxide evaporator, when the device half load production runs, use steam heater, improve the fuming sulfuric acid temperature of entering sulfur trioxide evaporator through high -temperature steam heating, and liquid sulfur trioxide yield can be improved from 46% to 78%, and the device realizes automatic operation through the introduction of self -control electrical instrument, reduces manual intervention frequency, guarantees the safety of production activity and improves economic benefit. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is the overall system principle drawing of the utility model;

[0030] Drawing mark: absorption tower 1, buffer chamber 101, outlet pipe 102, heat exchanger 2, steam heater 3, bypass pipe 301, sulfur trioxide evaporator 4, first cooler 5, second cooler 6, feed pump 7, first pump 8, second pump 9, fan 10, steam regulating valve 11, drain valve 12, acid inlet valve 13, bypass valve 14, acid outlet valve 15, high -temperature regulating valve 16, first temperature control valve 17, second temperature control valve 18, remote thermometer one 19, remote thermometer two 20, remote thermometer three 21, remote thermometer four 22, remote thermometer five 23, first thermometer 24, second thermometer 25, remote up acid instrument 26, remote back acid instrument 27, remote pH meter 28, remote pressure gauge 29, first packing layer 30, second packing layer 31. DETAILED DESCRIPTION

[0031] It should be understood that the terms "bottom, inlet, outlet, bottom, below, one side, top" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. The electrical appliances in this application, such as: feed pump 7, primary pump 8, secondary pump 9, fan 10, steam regulating valve 11, acid inlet valve 13, bypass valve 14, acid outlet valve 15, high temperature regulating valve 16, primary temperature control valve 17, secondary temperature control valve 18, remote thermometer 19, remote thermometer 20, remote thermometer 21, remote thermometer 22, remote thermometer 23, primary thermometer 24, secondary thermometer 25, remote acid meter 26, remote acid meter 27, remote pH meter 28, remote pressure gauge 29 are all powered by external power supply.

[0032] The absorption tower 1 is an absorption tower for oleum; the shell side of the heat exchanger 2 is high-concentration high-temperature oleum for absorbing sulfur trioxide; the tube side of the heat exchanger 2 is low-concentration low-temperature oleum for releasing sulfur trioxide; the sulfur trioxide evaporator 4 is an evaporator for evaporating sulfur trioxide; the fan 10 is a fan for feeding; the high-temperature regulating valve 16 is a regulating valve for high-temperature flue gas; the primary regulating valve 17 is a regulating valve for primary temperature control; the secondary regulating valve 18 is a regulating valve for secondary temperature control; the primary thermometer 24 is a thermometer for primary oleum; the secondary thermometer 25 is a thermometer for secondary oleum; the remote acid meter 26 is an instrument for remotely transmitting the concentration of the upper acid; the remote acid meter 27 is an instrument for remotely transmitting the concentration of the lower acid;

[0033] The primary packing layer 30 and the secondary packing layer 31 are metal packing layers, and the metal packing layer is composed of structured packing and stepped ring, and the material is 316L stainless steel;

[0034] The fan 10 is purchased from Xinxiang Sima Blower Co., Ltd. 700BSBD40 type and its related supporting power supply and circuit;

[0035] The steam regulating valve 11 is purchased from Chongqing Chuan Instrument Co., Ltd. HCP-10000 type and its related supporting power supply and circuit;

[0036] The acid inlet valve 13 is purchased from Antze Valve (Taicang) Co., Ltd. F-2-ISO-STD-RH type and its related supporting power supply and circuit; the bypass valve 14 and the acid outlet valve 15 are the same as the acid inlet valve 13;

[0037] The high-temperature regulating valve 16 is purchased from Chongqing Chuan Instrument Co., Ltd. VBJG-300022 type and its related supporting power supply and circuit;

[0038] The primary temperature control valve 17 was purchased from Chongqing Chuanyi Control Valve Co., Ltd., model VBJG-300002, along with its related power supply and circuit. The secondary temperature control valve 18 is the same as the primary temperature control valve 17.

[0039] The remote thermometer 19 was purchased from Suzhou Yokogawa Group Co., Ltd., model HHSBWZ / 2481, along with its related power supply and circuit. The remote thermometers 20, 31, 42, 52, 14, and 25 are the same as the remote thermometer 19.

[0040] The remote acid transfer device 26 was purchased from FoxboRo Corporation, model 876EC-TYAA-7, along with its associated power supply and circuitry; the remote acid return device 27 is the same as the remote acid transfer device 26.

[0041] The remote pH meter 28 was purchased from Endress+Hauser Analytical Instruments (Suzhou) Co., Ltd., model CM442-6J67 / 0, along with its related power supply and circuitry.

[0042] The remote pressure gauge 29 was purchased from Beijing Far East Rosemount Instrument Co., Ltd., model 3051GP2A2B21BB4M5HR5, along with its related power supply and circuit.

[0043] The interlocking protection program was purchased from Emerson, and its name is DeltaV. TM The distributed control system, version R6 (Chinese version), is compatible with the electrical components described in this application. These components include controllers, sensors, receivers, and processors. This application does not improve upon existing commercially available electrical components, circuits, or control programs. The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0044] Example 1

[0045] like Figure 1 As shown, an apparatus for improving the yield of sulfur trioxide includes an absorption tower 1, with a feed pump 7, a primary pump 8 and a secondary pump 9 connected in sequence to the pump trough at the bottom of the absorption tower 1.

[0046] The outlet of feed pump 7 is connected to the shell-side inlet of heat exchanger 2. The shell-side outlet pipe of heat exchanger 2 is equipped with a remote thermometer 20. The shell-side outlet pipe of heat exchanger 2 is connected in parallel to the bypass pipe 301 of the shell-side material of steam heat exchanger 3 and the acid inlet pipe of the shell-side inlet. The acid inlet pipe is also equipped with an acid inlet valve 13. The bypass pipe 301 of the shell-side material of steam heat exchanger 3 and the shell-side outlet pipe of steam heater 3 are connected in parallel to the tube-side inlet pipe of sulfur trioxide evaporator 4. Sulfur trioxide evaporator 4 is connected to the tube-side inlet of heat exchanger 2 through the tube-side liquid outlet pipe and the remote thermometer 22. Heat exchanger 2 is connected to absorption tower 1 through the tube-side outlet pipe.

[0047] The absorption tower 1 is provided with a first packing layer 30 and a second packing layer 31, a buffer chamber 101 is arranged between the top of the first packing layer 30 and the bottom of the second packing layer 31, the buffer chamber 101 is communicated with the inlet of an outlet pipe 102, the outlet of the outlet pipe 102 is communicated with the bottom of the absorption tower 1 and is arranged below the first packing layer 30.

[0048] A first cooler 5 and a first temperature control valve 17 are further arranged in parallel on the outlet pipe of the first pump 8, the inlet pipe of the first temperature control valve 17 and the inlet pipe of the shell side of the first cooler 5 are in parallel, the outlet pipe of the first temperature control valve 17 and the outlet pipe of the shell side of the first cooler 5 are in parallel; a first thermometer 24 is arranged at the side of the junction of the parallel outlet pipes.

[0049] A second cooler 6 and a second temperature control valve 18 are further arranged in parallel on the outlet pipe of the second pump 9, the inlet pipe of the second temperature control valve 18 and the inlet pipe of the shell side of the second cooler 6 are in parallel, the outlet pipe of the second temperature control valve 18 and the outlet pipe of the shell side of the second cooler 6 are in parallel, and a second thermometer 25 is arranged at the side of the junction of the parallel outlet pipes.

[0050] A remote thermometer three 21 is further arranged on the pipe side inlet pipe of the sulfur trioxide evaporator 4, the top of the sulfur trioxide evaporator 4 is communicated with the inlet of a fan 10 through a pipe side gas outlet pipe and a remote pressure gauge 29, the outlet of the fan 10 is communicated with a rectifying tower.

[0051] The inlet pipe of the absorption tower 1 is arranged below the first packing layer 30, and a tail gas pipe is further arranged at the top end of the absorption tower 1, the tail gas pipe is connected with the sulfur-burning acid-making first absorption tower.

[0052] The pipe side inlet of the steam heater 3 is connected with a steam pipe, a steam regulating valve 11 is arranged on the steam pipe, the pipe side outlet of the steam heater 3 is connected with a condensed water pipe, a trap valve 12 and a remote pH meter 28 are arranged on the condensed water pipe, the shell side outlet pipe of the steam heater 3 is communicated with the pipe side inlet pipe of the sulfur trioxide evaporator 4 through a bypass pipe 301 in parallel, the bypass pipe 301 is provided with a bypass valve 14, and the shell side outlet pipe of the steam heater 3 is further provided with an acid outlet valve 15.

[0053] The pipe side outlet pipe of the heat exchanger 2 is further provided with a remote thermometer five 23 and a remote acid return instrument 27, and the pipe side outlet of the heat exchanger 2 is communicated with the second pump 9 separation tank in the absorption tower 1.

[0054] The liquid under end of the pump between the feed pump 7 and the first pump 8 is separated by a partition plate, the liquid under end of the pump between the first pump 8 and the second pump 9 is separated by a partition plate, one side of the bottom of the first pump 8 is communicated with the bottom of the feed pump 7, the other side of the bottom of the first pump 8 is communicated with the bottom of the second pump 9, the outlet pipe of the first pump 8 is communicated with the buffer chamber inlet pipe of the absorption tower 1, the outlet pipe of the second pump 9 is communicated with the top chamber inlet of the second packing layer 31 in the absorption tower 1, and the outlet of the feed pump 7 is communicated with the shell side inlet of the heat exchanger 2 through a pipeline and a remote upper acid instrument 26 and a remote thermometer one 19.

[0055] The shell-side inlet pipe of the sulfur trioxide evaporator 4 is connected to the high-temperature flue gas pipe; the shell-side outlet pipe of the sulfur trioxide evaporator 4 is connected to the low-temperature flue gas pipe through the high-temperature regulating valve 16.

[0056] Preferably, steam is introduced into the tube inlet of the steam heater 3, and the fluids in the tube and shell sides exchange heat in a co-current manner. The tube outlet of the steam heater 3 is connected to a steam condensate tank to make full use of the heat of the condensate.

[0057] Preferably, high-temperature flue gas is introduced into the shell-side inlet of the sulfur trioxide evaporator 4, and the fluid in the shell-side and tube-side of the sulfur trioxide evaporator 4 exchanges heat in a countercurrent manner.

[0058] Preferably, circulating cooling water is introduced into the tube side inlet of the first-stage cooler 5, and the fluids in the tube side and shell side exchange heat in a countercurrent manner. The tube side inlet of the first-stage cooler 5 is connected to the circulating water tank through a water pump.

[0059] Preferably, circulating cooling water is introduced into the tube side inlet of the secondary cooler 6, and the fluids in the tube side and shell side exchange heat in a countercurrent manner. The tube side inlet of the secondary cooler 6 is connected to the circulating water tank through a water pump.

[0060] Preferably, high-concentration sulfur trioxide flue gas is introduced into the feed pipe of the absorption tower 1, and the tail gas pipe at the top of the absorption tower 1 is located above the connection between the outlet pipe and the absorption tower 1 and the secondary thermometer 25.

[0061] Preferably, the shell-side outlet pipe of the sulfur trioxide evaporator 4 is connected to the sulfuric acid tail gas absorption tower via a high-temperature regulating valve 16 and a low-temperature flue gas pipeline.

[0062] Example 2

[0063] like Figure 1 As shown, an apparatus for improving sulfur trioxide yield includes an absorption tower 1, a heat exchanger 2, a steam heater 3, a sulfur trioxide evaporator 4, a primary cooler 5, and a secondary cooler 6. Sulfur trioxide flue gas from the third stage of the converter enters from the bottom of the absorption tower 1, passes through the primary metal packing layer 30 and the secondary metal packing layer 31 in sequence, and is absorbed by fuming sulfuric acid in two stages. The tail gas after absorption is treated in the first absorption tower of the sulfuric acid production process. After the concentration of fuming sulfuric acid in the absorption tower 1 is increased, it is fed by the feed pump 7 into the heat exchanger 2, the steam heater 3, and the sulfur trioxide evaporator 4 in sequence for heating. Gas-phase SO3 evaporates from the fuming sulfuric acid and enters the feed fan 10 from the top of the sulfur trioxide evaporator 4, and is sent to the sulfur trioxide distillation process to produce high-purity liquid SO3. Low-concentration fuming sulfuric acid overflows from the top of the sulfur trioxide evaporator 4 back to the heat exchanger 2 for heat exchange, and finally enters the pump tank of the absorption tower 1. After being pressurized by the primary pump 8 and the secondary pump 9, it enters the absorption tower 1 to spray and absorb SO3 in the flue gas.

[0064] In the preferred scheme, the absorption tower 1 is a tower and pump tank integrated device, the pump tank of the absorption tower 1 is sequentially provided with the feeding pump 7, the first-stage pump 8 and the second-stage pump 9, the three pumps are all submerged pumps, the device is reasonably arranged, land is saved, the submerged ends of the pumps are separated by the isolation plates, the bottoms are communicated with each other, the oleum in the pump tank forms a concentration gradient; the tower is sequentially filled with the first-stage filler layer 30 and the second-stage filler layer 31, the flow distribution of the oleum at the top of the tower is more uniform, the oleum is fully contacted with the sulfur trioxide flue gas, and the SO3 is absorbed.

[0065] In the preferred scheme, the outlet of the first-stage pump 8 is connected with the first-stage cooler 5, the first-stage cooler 5 is provided with the first-stage temperature control valve 17, the first-stage cooler 5 and the first-stage temperature control valve 17 are connected in parallel, the parallel outlet is provided with the first-stage nicotinic acid thermometer 24, the outlet of the second-stage pump 9 is connected with the second-stage cooler 6, the second-stage cooler 6 and the second-stage temperature control valve 18 are connected in parallel, the outlet of the parallel pipeline of the second-stage cooler 6 and the second-stage temperature control valve 18 is provided with the second-stage nicotinic acid thermometer 25, the first-stage cooler 5 and the second-stage cooler 6 are both cooled by circulating cooling water, the temperature of the oleum entering the tower and passing through the first-stage cooler 5 and the second-stage cooler 6 is accurately controlled by the first-stage temperature control valve 17 and the second-stage temperature control valve 18.

[0066] In the preferred scheme, the outlet of the feeding pump 7 is connected with the heat exchanger 2, then the outlet is connected with the shell side of the steam heater 3, the oleum in the shell side of the steam heater 3 is heated by the high-temperature steam in the tube side of the steam heater 3, then the oleum is heated to the boiling point temperature by the high-temperature flue gas from the four layers of the converter in the shell side of the sulfur trioxide evaporator 4, and the flue gas at the outlet of the shell side is treated in the sulfur-burning sulfuric acid tail gas treatment device; the gaseous sulfur trioxide evaporates from the oleum, the gaseous sulfur trioxide is sent to the sulfur trioxide rectification process through the gas-phase pipeline at the top of the sulfur trioxide evaporator 4 and the fan 10; the liquid phase is low-concentration oleum, which overflows from the upper part of the tube side of the sulfur trioxide evaporator 4 to the tube side of the heat exchanger 2, heats the oleum in the shell side of the heat exchanger 2 and finally returns to the pump tank of the absorption tower 1.

[0067] In the preferred scheme, the inlet acid pipe, the outlet acid pipe and the shell side material bypass pipe 301 of the oleum in the shell side of the steam heater 3 are respectively provided with the inlet acid valve 13, the outlet acid valve 15 and the bypass valve 14, the steam inlet pipe of the tube side of the steam heater 3 is provided with the steam regulating valve 11, the condensate water pipeline of the tube side of the steam heater 3 is provided with the trap valve 12 and the remote pH meter 28, when the pH of the condensate water reaches the interlocking alarm value, the interlocking protection program is started, the bypass valve 14 is opened, the steam regulating valve 11, the inlet acid valve 13 and the outlet acid valve 15 are closed, and the safe and stable operation of the device is ensured.

[0068] In the preferred scheme, the sulfur trioxide evaporator 4 is heated by the flue gas outlet pipeline with a high temperature regulating valve 16, the sulfur trioxide evaporator inlet and outlet pipelines are respectively provided with remote thermometer three 21 and remote thermometer four 22, and the steam regulating valve 11 and the high temperature regulating valve 16 are respectively connected with the remote thermometer three 21 and the remote thermometer four 22 for automatic control interlocking, so that the temperature of the fuming sulfuric acid in the sulfur trioxide evaporator 4 can be accurately controlled.

[0069] In the preferred scheme, the inlet pipeline of the feed fan 10 is connected with the top gas phase port of the sulfur trioxide evaporator 4, and a remote pressure gauge 29 is arranged on the inlet pipeline. The motor of the feed fan 10 is a variable frequency motor, and the variable frequency of the feed fan 10 is connected with the remote pressure gauge 29 for automatic control interlocking, so that the top gas phase space of the sulfur trioxide evaporator 4 is always in a slight positive pressure, the flashing rate of the fuming sulfuric acid is accelerated, and the evaporation efficiency of the sulfur trioxide evaporator is improved.

[0070] In the preferred scheme, the pump tank of the absorption tower 1 is provided with a partition plate. The liquid end of the feed pump 7 is connected with the fuming sulfuric acid after absorbing the sulfur trioxide flue gas, and the liquid end of the secondary pump 9 is connected with the fuming sulfuric acid after being heated by the heat exchanger 2. The high-temperature and high-concentration fuming sulfuric acid is sequentially sent to the heat exchanger 2, the steam heater 3 and the sulfur trioxide evaporator 4 for heating and SO3 precipitation, and the low-temperature and low-concentration fuming sulfuric acid is sent to the absorption tower 1, so that the sulfur trioxide yield is further improved. Meanwhile, the motors of the feed pump 7, the primary pump 8 and the secondary pump 9 are variable frequency motors, which is helpful to realize automatic control.

[0071] In the preferred scheme, the outlet acid pipeline of the feed pump 7 and the heat exchanger 2 pipeline are respectively provided with a remote acid instrument 26 and a remote return acid instrument 27. The remote return acid instrument 27 is connected with the steam regulating valve 11 and the high temperature regulating valve 16 for safety interlocking. When the acid concentration reaches the interlocking alarm value, the steam regulating valve 11 and the high temperature regulating valve 16 are closed to prevent the low-concentration fuming sulfuric acid from corroding the equipment and ensure the safe and stable operation of the device.

[0072] In the preferred scheme, as shown in Figure 1 The primary cooler 5 and the secondary cooler 6 are connected with the circulating cooling water for heat exchange, and the circulating water returns to the circulating water pool for recycling. The outlet acid pipelines of the primary cooler 5 and the secondary cooler 6 are respectively provided with a primary thermometer 24 and a secondary thermometer 25. The inlet fuming sulfuric acid is controlled at 45-50℃ by controlling the opening degrees of the primary temperature control valve 17 and the secondary temperature control valve 18, and the secondary thermometer 25 is controlled at 40-45℃.

[0073] In the preferred scheme, as shown in Figure 1As shown, the steam heater 3 uses 0.4-0.6 MPa high temperature steam heating, the steam condensate pipeline is provided with a trap 12 and a remote pH meter 28, the pH value is controlled at 7.5-9, the outlet of the steam heater 3 is connected with a oleum pipeline provided with a remote thermometer three 21, the opening of the steam regulating valve 11 is controlled to control the temperature of the remote thermometer three 21 at 95-110℃.

[0074] The preferred scheme is as shown in Figure 1 As shown, the shell side of the sulfur trioxide evaporator 4 uses high temperature flue gas from the fourth stage of the converter in the sulfuric acid production process for heating, the tail gas is treated in the second absorption tower in the sulfuric acid production process, a high temperature regulating valve 16 is installed on the tail gas outlet pipe of the shell side of the sulfur trioxide evaporator 4, and an oleum remote thermometer four 22 is installed on the overflow outlet pipeline of the upper part of the tube side of the sulfur trioxide evaporator 4, the opening of the high temperature regulating valve 16 is controlled to control the temperature of the remote thermometer four 22 at 1100-120℃.

[0075] The preferred scheme is as shown in Figure 1 As shown, the gas phase pipe at the top of the tube side of the sulfur trioxide evaporator 4 is connected with the inlet of the feeding fan 10, the outlet of the feeding fan 10 is connected with the sulfur trioxide rectification process to produce high purity liquid sulfur trioxide, and a remote pressure 29 is installed on the gas phase pipe of the sulfur trioxide, the pressure of the remote pressure 29 is controlled at 0-5 kPa by frequency conversion of the feeding fan 10.

[0076] The preferred scheme is as shown in Figure 1 As shown, the oleum pipeline at the outlet of the feeding pump 7 is provided with a remote upper acid instrument 26 to control the acid concentration at 36-42%, and the oleum pipeline of the heat exchanger 2 returning to the pump tank is provided with a remote return acid instrument 27 to control the acid concentration at 24-40%.

[0077] The preferred scheme is as shown in Figure 1 As shown, the steam regulating valve 11, the acid feeding valve 13, the acid outlet valve 15, the bypass valve 14 and the remote pH meter 28 are provided with safety interlocking inside; when the remote pH meter is lower than 7 and reaches the interlocking alarm value, the interlocking is triggered, the bypass valve 14 is opened, and the steam regulating valve 11, the acid feeding valve 13 and the acid outlet valve 15 are closed to prevent corrosion of the equipment after leakage, ensure stable operation of the device and improve the intrinsic safety of the device.

[0078] The preferred scheme is as shown in Figure 1 As shown, the remote return acid instrument 27, the steam regulating valve 11 and the high temperature regulating valve 16 are provided with safety interlocking inside; when the remote return acid instrument 27 is lower than 23% and reaches the interlocking alarm value, the interlocking is triggered, the steam regulating valve 11 and the high temperature regulating valve 16 are closed to prevent corrosion of the equipment by low concentration oleum and improve the intrinsic safety of the device.

[0079] The operation principle of the device is as shown below:

[0080] 1. When the liquid sulfur trioxide unit is operating at full load, the steam heater 3 is not used. The bypass valve 14 is opened, and the steam regulating valve 11, acid inlet valve 13, and acid outlet valve 15 are closed. The temperature of the overflow fuming sulfuric acid at the top of the sulfur trioxide evaporator tubes is controlled by the high-temperature regulating valve 16. The temperature of the remote thermometer 22 is controlled at 100-120℃, and the yield of liquid sulfur trioxide can reach 74%.

[0081] 2. When the liquid sulfur trioxide unit is operating at full load, the steam heater 3 is activated, the acid inlet valve 13 and the acid outlet valve 15 are opened, the bypass valve 14 is closed, and the temperature of the fuming sulfuric acid entering the sulfur trioxide evaporator 4 is controlled by adjusting the opening of the steam regulating valve 11. The temperature of the remote thermometer 21 is controlled at 95-110℃. The temperature of the overflow fuming sulfuric acid in the upper part of the tube side of the sulfur trioxide evaporator 4 is controlled by adjusting the opening of the high temperature regulating valve 16. The temperature of the remote thermometer 22 is controlled at 100-120℃. This can achieve a liquid sulfur trioxide yield of 78%.

[0082] 3. When the liquid sulfur trioxide unit is operating at 50% capacity, the steam heater 3 is not used. The bypass valve 14 is opened, and the steam regulating valve 11, acid inlet valve 13, and acid outlet valve 15 are closed. The temperature of the overflow fuming sulfuric acid at the top of the sulfur trioxide evaporator tubes is controlled by the high-temperature regulating valve 16. The remote thermometer 22 can reach a maximum of 100°C, and the liquid sulfur trioxide yield can reach a maximum of 46%.

[0083] 4. When the liquid sulfur trioxide unit is operating at 50% capacity, the steam heater 3 is activated, the bypass valve 14 is closed, and the acid inlet valve 13 and acid outlet valve 15 are opened. The temperature of the fuming sulfuric acid in the tube side of the sulfur trioxide evaporator 4 is controlled by the steam regulating valve 11, and the temperature of the remote thermometer 21 is controlled at 95-110℃. The temperature of the overflow fuming sulfuric acid in the upper part of the tube side of the sulfur trioxide evaporator 4 is controlled by the high temperature regulating valve 16, and the temperature of the remote thermometer 22 is controlled at 100-120℃. The liquid sulfur trioxide yield can reach up to 78%.

[0084] Furthermore, the description of this invention is merely a preferred embodiment and is not intended to limit the invention. Although the invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention. The instrument model selected in this application is only for ease of explanation and is not intended to limit the use of this particular instrument model in this application.

Claims

1. A device for increasing the yield of sulfur trioxide, comprising an absorption column (1), characterized in that, The absorption tower (1) is sequentially communicated with a feeding pump (7), a first-stage pump (8) and a second-stage pump (9) on a pump tank at the bottom of the absorption tower (1). The outlet of the feeding pump (7) is communicated with the inlet of the shell side of a heat exchanger (2), the outlet pipe of the shell side of the heat exchanger (2) is provided with a remote thermometer No.2 (20), the outlet pipe of the shell side of the heat exchanger (2) is in parallel communication with a bypass pipe (301) of the shell side material of a steam heat exchanger (3) and an acid feeding pipe of the shell side inlet, the acid feeding pipe is further provided with an acid feeding valve (13), the bypass pipe (301) of the shell side material of the steam heat exchanger (3) and the outlet pipe of the shell side of the steam heat exchanger (3) are in parallel communication with the inlet pipe of the pipe side of a sulfur trioxide evaporator (4), the sulfur trioxide evaporator (4) is communicated with the inlet of the pipe side of the heat exchanger (2) through the pipe side liquid outlet pipe and the remote thermometer No.4 (22), and the heat exchanger (2) is communicated with the absorption tower (1) through the pipe side outlet pipe.

2. A device for increasing the yield of sulfur trioxide according to claim 1, characterized in that The absorption tower (1) is provided with a first-stage filler layer (30) and a second-stage filler layer (31), a buffer chamber (101) is arranged between the top of the first-stage filler layer (30) and the bottom of the second-stage filler layer (31), the buffer chamber (101) is communicated with the inlet of an outlet pipe (102), and the outlet of the outlet pipe (102) is communicated with the bottom of the absorption tower (1) and arranged below the first-stage filler layer (30).

3. The apparatus of claim 1, wherein the apparatus further comprises a condenser for condensing the sulfur trioxide. 5 The outlet pipe of the first-stage pump (8) is further provided with a first-stage cooler (5) and a first-stage temperature control valve (17) in parallel, the inlet pipe of the first-stage temperature control valve (17) and the inlet pipe of the shell side of the first-stage cooler (5) are in parallel, the outlet pipe of the first-stage temperature control valve (17) and the outlet pipe of the shell side of the first-stage cooler (5) are in parallel, and a first-stage thermometer (24) is arranged on the side of the intersection of the parallel outlet pipes.

4. The apparatus of claim 1, wherein the apparatus is characterized by: The outlet pipe of the second-stage pump (9) is further provided with a second-stage cooler (6) and a second-stage temperature control valve (18) in parallel, the inlet pipe of the second-stage temperature control valve (18) and the inlet pipe of the shell side of the second-stage cooler (6) are in parallel, the outlet pipe of the second-stage temperature control valve (18) and the outlet pipe of the shell side of the second-stage cooler (6) are in parallel, and a second-stage thermometer (25) is arranged on the side of the intersection of the parallel outlet pipes.

5. The apparatus of claim 1, wherein the apparatus is characterized by: The inlet pipe of the pipe side of the sulfur trioxide evaporator (4) is further provided with a remote thermometer No.3 (21), the top of the sulfur trioxide evaporator (4) is communicated with the inlet of a fan (10) through the pipe side gas outlet pipe and a remote pressure gauge (29), and the outlet of the fan (10) is communicated with a rectifying tower.

6. The apparatus of claim 1, wherein the apparatus is characterized by: The feeding pipe of the absorption tower (1) is arranged below the first-stage filler layer (30), and the absorption tower (1) is further provided with a tail gas pipe at the top end, the tail gas pipe is connected with a sulfur-burning acid-making first-stage tower.

7. The apparatus of claim 1, wherein the apparatus is configured to increase the yield of sulfur trioxide. The pipe side inlet of the steam heat exchanger (3) is connected with a steam pipe, the steam pipe is provided with a steam adjusting valve (11), the pipe side outlet of the steam heat exchanger (3) is connected with a condensed water pipe, the condensed water pipe is provided with a trap valve (12) and a remote pH meter (28), the outlet pipe of the shell side of the steam heat exchanger (3) and the bypass pipe (301) are in parallel communication with the inlet pipe of the pipe side of the sulfur trioxide evaporator (4), the bypass pipe (301) is provided with a bypass valve (14), and the outlet pipe of the shell side of the steam heat exchanger (3) is further provided with an acid outlet valve (15).

8. The apparatus of claim 1, wherein the apparatus is configured to increase the yield of sulfur trioxide. The heat exchanger (2) pipe outlet pipe is further provided with a remote thermometer five (23) and a remote return acid instrument (27); the pipe outlet of the heat exchanger (2) is communicated with the secondary pump (9) separation tank in the absorption tower (1).

9. The apparatus of claim 1, wherein, The liquid under end of the pump between the feed pump (7) and the primary pump (8) is separated by a partition plate, the liquid under end of the pump between the primary pump (8) and the secondary pump (9) is separated by a partition plate, the bottom of the feed pump (7) is communicated with one side of the bottom of the primary pump (8), the other side of the bottom of the primary pump (8) is communicated with the bottom of the secondary pump (9); the outlet pipe of the primary pump (8) is communicated with the buffer chamber inlet pipe of the absorption tower (1); the outlet pipe of the secondary pump (9) is communicated with the secondary packing layer (31) top chamber inlet in the absorption tower (1); the outlet of the feed pump (7) is communicated with the shell side inlet of the heat exchanger (2) through a pipeline and a remote upper acid instrument (26) and a remote thermometer one (19).

10. The apparatus of claim 1, wherein, The shell side inlet pipe of the sulfur trioxide evaporator (4) is communicated with a high-temperature flue gas pipe; the shell side outlet pipe of the sulfur trioxide evaporator (4) is communicated with a low-temperature flue gas pipe through a high-temperature adjusting valve (16).

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