Condensing water-removing device for on-line analysis of butadiene tail gas

Abstract

The utility model discloses a butadiene tail gas on -line analysis condensing water removal device, containing sample gas condenser and vortex tube refrigerator, sample gas condenser vertical installation, from butadiene tail gas sample gas is from bottom sample gas sample extension pipe and enters sample gas condenser pipe course, after through sample gas condenser inner row pipe, is connected to on -line analysis appearance through top's sample gas output pipe, vortex tube refrigerator drive gas interface accesses instrument wind, and the refrigerant output end is connected with sample gas condenser upper refrigerant inlet, and hot gas output end discharges atmosphere. Sample gas condenser inner row pipe temperature control range is 0 2 DEG C, and the moisture in sample gas is low temperature condensation in row pipe, and flows to sample gas condenser bottom along row pipe inner wall, until reflux to technological pipeline. The device water removal efficiency reaches 95% or more, satisfies various on -line analysis instrument detection demand.

Description

Technical Field

[0001] This utility model belongs to the field of online analysis sample processing technology, specifically relating to a butadiene tail gas online analysis sample gas condensation and dehydration device. Background Technology

[0002] Butadiene tail gas emissions require adsorption-desorption and catalytic combustion treatment. The moisture content of the tail gas formed after steam desorption and catalytic combustion mixes with air varies greatly. For production safety and environmental protection considerations, tail gas composition analysis must be performed before treatment and emission. Due to the presence of water vapor, dehydration and drainage of the sample gas are indispensable pretreatment processes before tail gas analysis and testing. Under conditions of low tail gas pressure and low flow rate, traditional gas-liquid separation methods do not completely separate moisture; automatic drainage with condensate traps is not feasible, as large fluctuations in sample gas pressure affect analytical measurements, and manual periodic drainage after condensate accumulation increases the workload.

[0003] Therefore, actual production requires continuous and undisturbed water removal and drainage of low-pressure, low-flow sample gas. Summary of the Invention

[0004] This invention provides an online analysis, condensation, and dehydration device for butadiene tail gas, which can realize the condensation of moisture in butadiene tail gas, water-gas separation, and self-reflux, and achieve automatic dehydration and drainage of sample gas.

[0005] The above-mentioned objectives are achieved by the following technical solutions.

[0006] A butadiene tail gas online analysis condensation and dehydration device is characterized by comprising a sample gas condenser and a vortex tube cooler. The sample gas condenser is vertically installed. The sample gas from the butadiene tail gas enters the tube side of the sample gas condenser from the bottom sample gas inlet extension tube, passes through the inner tubes of the sample gas condenser, and is connected to the online analyzer via the top sample gas outlet tube. The vortex tube cooler's drive gas interface is connected to the instrument air, its refrigerant outlet is connected to the refrigerant inlet at the top of the sample gas condenser, and its hot gas outlet is discharged into the atmosphere.

[0007] In the device described above, the sample gas condenser is a low-temperature condensation device, which uses a refrigerant provided by a vortex tube cooler to cool the internal tubes of the sample gas condenser to about 0°C.

[0008] Furthermore, the bottom of the sample gas condenser is an arc-shaped bottom surface, and the lowest point of the end cap is connected to the butadiene tail gas process pipeline as a condensate return port.

[0009] Furthermore, the refrigerant outlet at the bottom of the sample gas condenser is connected to a silencer for atmospheric emission.

[0010] Furthermore, a temperature sensor is installed in the middle of the sample gas condenser to detect its internal temperature, and the temperature sensor signal is connected to a PLC (Programmable Logic Controller).

[0011] Furthermore, the device is equipped with a micro-flow regulating valve at the drive gas interface of the vortex tube cooler to control the instrument airflow of the vortex tube cooler. The regulating valve control signal is controlled by a PLC.

[0012] The device provides refrigerant to the sample gas condenser through a vortex tube cooler, and continuously controls the temperature of the sample gas condenser through a temperature sensor and a micro-flow regulating valve, with a temperature control range of 0±2℃; in order to avoid freezing and blockage inside the sample gas condenser due to excessively low temperature, or failure of water removal due to excessively high temperature.

[0013] Furthermore, the end of the bottom sample gas inlet extension tube is vertically inserted into the center of the butadiene tail gas process pipeline.

[0014] The butadiene tail gas online analysis condensation and dehydration device described above has a sample gas condenser installed vertically to the ground to facilitate the return of condensate. The dried sample gas after condensation and dehydration is sent to the online analyzer from the top outlet of the sample gas condenser. The condensate flows downstream through the condenser tubes back to the bottom of the condenser and then returns to the process pipeline.

[0015] Furthermore, the flange connecting the bottom of the sample gas condenser to the sampling port of the process pipeline is thickened, and a through hole is machined on the outer edge of the flange to the center of the flange. The sample gas returned after online analysis is connected to the through hole interface on the outer edge of the flange and returned to the process pipeline.

[0016] Beneficial Effects: This novel online butadiene tail gas analysis condensation and dehydration device effectively solves the problems of incomplete water removal from sample gas and the impact of hydrophobic condensate on sample gas pressure. The sample gas condenser is vertically installed, and the condensed water undergoes self-recirculation under gravity. Furthermore, the flow rate of the vortex tube cooler is adjusted, thereby achieving precise temperature control within the condenser, improving sample gas dehydration efficiency and preventing potential condensate freezing. It boasts high reliability and high dehydration efficiency, providing conditions for reliable and stable online analysis measurements. This device achieves a dehydration efficiency of over 95%, meeting the testing requirements of various online analytical instruments, and is also applicable to sample gas dehydration under low flow and low pressure conditions in other process systems. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the practical structure of this new invention.

[0018] In the diagram: 1-Sample gas condenser; 1a-Tube; 1b-Sample gas inlet extension tube; 1c-Sample gas outlet; 1d-Refrigerant inlet; 1e-Refrigerant outlet; 1f-Condensate drain; 1g-Sample gas return tube; 2-Vortex tube cooler; 2a-Vortex tube cooler hot gas outlet; 3-Temperature sensor; 4-Micro flow regulating valve; 5-Instrument air. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 An online analysis, condensation, and dehydration device for butadiene tail gas includes a sample gas condenser 1; a vortex tube cooler 2; a temperature sensor 3; a micro-flow regulating valve 4; an instrument fan 5; and a PLC control unit.

[0021] The sample gas condenser 1 is installed vertically to the ground. The sample gas from the butadiene tail gas flows from the sample gas inlet extension tube 1b at the bottom of the sample gas condenser 1 through the tubes 1a of the sample gas condenser 1 to the sample gas outlet 1c at the top, which is then delivered to the online analyzer. The end of the condenser inlet extension tube 1b is inserted into the center of the process pipeline.

[0022] The instrument air 5 is connected to the inlet of the micro-flow regulating valve 4, and the outlet of the micro-flow regulating valve 4 is connected to the air inlet of the vortex tube cooler 2.

[0023] The refrigerant interface of the vortex tube cooler 2 is connected to the refrigerant inlet 1d of the sample gas condenser 1. After being cooled by the tubes 1a of the sample gas condenser 1, the refrigerant is discharged to the atmosphere from the refrigerant outlet 1e. The hot gas outlet 2a of the vortex tube cooler is also discharged to the atmosphere.

[0024] The temperature sensor 3 detects the temperature in the middle of the sample gas condenser 1, that is, the temperature of the outer wall of the tube 1a of the sample gas condenser 1. The temperature sensor 3 outputs a 4-20mA DC signal which is connected to the PLC.

[0025] The micro-flow regulating valve 4 is selected as a fault-open type and is controlled by the PLC.

[0026] The temperature sensor 3, the micro-flow regulating valve 4, and the PLC form a single-loop control system, implementing PID control. Specifically, when the temperature of the temperature sensor 3 rises, the output signal decreases after PID calculation by the PLC, the opening of the micro-flow regulating valve 4 increases, the instrument airflow of the vortex tube cooler 2 increases, the outlet temperature of the vortex tube cooler 2 decreases, and the temperature inside the sample gas condenser 1 decreases. Conversely, when the temperature of the temperature sensor 3 decreases, the temperature inside the sample gas condenser 1 increases.

[0027] After online analysis, the sample gas is refluxed back to the sample gas return pipe (1g) and then returned to the process pipeline.

[0028] This invention utilizes a vortex tube cooler to generate a refrigerant that condenses water vapor in the sample gas. The condensed water then flows back to the process pipeline under gravity. Furthermore, the internal temperature of the sample gas condenser is controlled to maintain a relatively constant condensation temperature at the optimal condensation level.

[0029] Example

[0030] Reference Figure 1 A butadiene tail gas online analysis, condensation, and dehydration device is constructed as described above. The specific components and parameters are as follows: (1) Partial selection Sample gas condenser, custom-machined. The sample gas condenser is 550mm in total length and Φ63mm in outer diameter; it is equipped with 14 Φ6x0.5mm thin-walled 316SS tubes, each 520mm long. Figure 1 As shown, the tube ends are welded to the flanges respectively. The sample gas inlet extension tube has a length of 850mm (process pipeline DN1600), and the sample gas inlet extension tube and outlet pipe are Φ6x1mm, 316SS.

[0031] Vortex tube cooler, a domestic brand.

[0032] Temperature sensor, domestic brand.

[0033] Miniature flow regulating valve, domestic brand.

[0034] (2) Performance parameters The sample gas flow rate is 0-50 L / min, and the pressure is 2 kPa. After the sample gas is dehydrated, it is pressurized by the self-priming pump built into the online analyzer.

[0035] Sample gas condenser. Heat exchange area 1250 cm². 2 .

[0036] Vortex tube cooler. Maximum inlet flow rate 420L / min@0.69MPag, maximum cooling capacity 1050BTU / h, output refrigerant extreme temperature -45~-50℃.

[0037] Temperature sensor. ExiaIICT4, two-wire 4-20mA DC, range -50~50℃, U-tube insertion depth 270mm, process interface 1 / 2NPT.

[0038] Miniature flow control valve. ExiaIICT4, two-wire 4-20mA DC, maximum flow rate 500 L / min, operating pressure 1.0 MPa, equal percentage flow characteristic, process interface ANSI 1 / 2” 150 lb RF.

[0039] PLC PID parameter settings: proportional gain 1.5, integral time 30s, derivative time 90s. Temperature setpoint 0℃.

[0040] The online analysis and condensation dehydration device for butadiene tail gas showed excellent performance, operating continuously for six months with sample gas condensation and dehydration, and self-draining. No liquid carryover or condenser blockage was observed during online analysis. Historical temperature trends inside the condenser during this period were recorded as follows: maximum 1.7℃, minimum -2.4℃.

Claims

1. A butadiene tail gas online analysis, condensation, and dehydration device, characterized in that, It includes a sample gas condenser and a vortex tube cooler. The sample gas condenser is installed vertically. The sample gas from butadiene tail gas enters the tube side of the sample gas condenser from the bottom sample gas inlet extension tube. After passing through the inner tube of the sample gas condenser, it is connected to the online analyzer through the sample gas outlet tube at the top. The drive gas interface of the vortex tube cooler is connected to the instrument air, the refrigerant outlet is connected to the refrigerant inlet at the top of the sample gas condenser, and the hot gas outlet is discharged into the atmosphere.

2. The butadiene tail gas online analysis, condensation, and dehydration device according to claim 1, characterized in that, The temperature control range of the inner tubes of the sample gas condenser is 0±2℃.

3. The butadiene tail gas online analysis, condensation, and dehydration device according to claim 1, characterized in that, The drive gas interface of the vortex tube cooler is equipped with a micro-flow regulating valve to control the instrument airflow of the vortex tube cooler. The control signal of the micro-flow regulating valve is controlled by a PLC.

4. The butadiene tail gas online analysis, condensation, and dehydration device according to claim 1, characterized in that, A temperature sensor is installed in the middle of the sample gas condenser, and the temperature sensor signal is connected to the PLC.

5. The butadiene tail gas online analysis, condensation, and dehydration device according to claim 1, characterized in that, The end of the sample gas inlet extension tube is vertically inserted into the center of the butadiene tail gas process pipeline.

6. The butadiene tail gas online analysis, condensation, and dehydration device according to claim 1, characterized in that, The bottom of the sample gas condenser is an arc-shaped bottom surface, and the lowest point of the end cap is connected to the butadiene tail gas process pipeline as a condensate return port.

7. The butadiene tail gas online analysis, condensation, and dehydration device according to claim 1, characterized in that, The sample gas condenser bottom is connected to the sampling port of the process pipeline via a flange. A through hole is machined on the outer edge of the flange to the center of the flange. The sample gas returned after online analysis is connected to the through hole interface on the outer edge of the flange and returned to the process pipeline.

8. The butadiene tail gas online analysis, condensation, and dehydration device according to claim 1, characterized in that, The sample gas condenser has a silencer at the lower refrigerant outlet for atmospheric emission.

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