Pretreatment device for sample gas at raw gas outlet of Lurgi furnace

Abstract

The utility model belongs to the technical field of industrial gas instrument measurement pretreatment, and particularly relates to a pretreatment device for sample gas at a raw gas outlet of a Lurgi gasifier, which comprises a pressure reducer, a gas inlet pipe arranged on one side of the pressure reducer, a pressure reducing pipe connected to the upper end of the pressure reducer, an emptying pipeline arranged at the lower end of the pressure reducer, and pressure reducing control valves arranged on the emptying pipeline and the pressure reducing pipe. One end of the decompression pipe is connected with a washing column; one side of the washing column is sequentially connected in series with a first-stage purification column and a second-stage purification column through a dewatering pipe, an outlet of the second-stage purification column is connected with a buffer column through a buffer pipe, and one side of the buffer column is connected with an exhaust pipe; according to the utility model, the dew point of the pretreated raw gas is lower than-20 DEG C, the treatment flows of cyclone dust removal, turbine water removal and other conditions requiring electricity and instrument wind are not needed, the process is simple, the device is small and exquisite, the pretreatment cost is greatly reduced, and the use is simple, convenient and quick; meanwhile, the determination efficiency and the O2 determination accuracy are greatly improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of pre-processing of industrial gas instrument measurement, and in particular relates to a pre-processing device for sample gas at a crude coal gas outlet of a Lurgi furnace. Background Art

[0002] At present, the coal-to-gas industry mostly uses Lurgi gasifiers. In order to ensure good gasification efficiency and safety, the frequency of testing the content of CO2 and O2 in the raw gas is very high, once every 15 minutes when starting, and once every 2 hours during normal operation. Since the crude gas exported contains high levels of oil, dust, and water, and is located in an explosion-proof area, it is impossible to use instruments for detection. Generally, the Ostwald absorption method is used for detection; due to the large number of Lurgi furnaces, the workload is large, the timeliness is poor, and there are high safety hazards. In addition, the sensitivity of the Ostwald instrument to measure oxygen is low. The lowest oxygen content that can be measured by the Ostwald instrument is 0.2%, while the actual content is generally 0.01% or lower.

[0003] There are systems for pretreatment of raw coal gas from Lurgi furnaces in the prior art. The invention patent with application publication number 202010976933.X discloses a sample gas pretreatment system for raw coal gas outlet from Lurgi coal gasification furnace, which includes the following: a condensation and oil removal device, a water seal device, a water washing device, a cyclone separator, a turbine dehumidifier, and a dehydration filter. In order to achieve the condition that the raw coal gas can enter the instrument for measurement, the system uses a condensation and oil removal device, a water seal device, a water washing device, a cyclone separator, a turbine dehumidifier, and a dehydration filter for pretreatment. The treatment process is relatively complicated, requiring the on-site conditions of electricity, instruments, wind, etc., and the cost is relatively high. Utility Model Content

[0004] In view of the above problems, the utility model provides a pretreatment device for raw coal gas outlet sample gas, which can directly use a portable composite gas measuring instrument to directly measure CO2 and O2 with high analysis frequency, greatly improving the measurement efficiency and accuracy of O2 measurement.

[0005] The technical solution of the utility model is: a pretreatment device for sample gas at the outlet of the crude coal gas of a Lurgi furnace, comprising a pressure reducer, an air inlet pipe is arranged on one side of the pressure reducer, a pressure reducing pipe is connected to the upper end of the pressure reducer, a venting pipeline is arranged on the lower end of the pressure reducer, pressure reducing control valves are arranged on the venting pipeline and the pressure reducing pipe, one end of the pressure reducing pipe is connected to a water washing column; a primary purification column and a secondary purification column are sequentially connected in series on one side of the water washing column through a dehydration pipe, the outlet of the secondary purification column is connected to the buffer column through a buffer pipe, one side of the buffer column is connected to an exhaust pipe, a three-way valve is arranged on the exhaust pipe, and the exhaust pipe is connected to an analytical instrument through the three-way valve.

[0006] Furthermore, the two pressure reducing control valves are both spherical valves; a pressure gauge is provided on the pressure reducing pipe, and the pressure gauge is arranged between the pressure reducing control valve and the water washing column.

[0007] Furthermore, the water wash column adjusts the gas volume and pressure through the pressure reducing pipe and the pressure reducing control valve on the vent line, so that the outlet pressure of the water wash column is reduced to 0.01MPa-0.75MPa, and preferably the pressure is reduced to 0.1MPa-0.4MPa.

[0008] Furthermore, the water washing column is a transparent organic glass column with a pressure resistance of 0.5 MPa.

[0009] Furthermore, a water washing air inlet and a drain valve are provided at the bottom end of the water washing column, the water washing air inlet is connected to the pressure reducing pipe, and the drain valve is connected to the drain pipe; a water washing air outlet valve and a water inlet valve are provided at the top end of the water washing column, the water washing air outlet valve is connected to the dehydration pipe, and a water inlet pipe is provided at the water inlet valve.

[0010] Furthermore, the first-level purification column and the second-level purification column connected in series are both transparent plexiglass columns, and the bottom ends of the first-level purification column and the second-level purification column are both provided with a dehydration air inlet valve and a drain valve, the dehydration air inlet valve is connected to the dehydration pipe, and the drain valve is connected to the drain pipe; the bottom ends of the first-level purification column and the second-level purification column are both provided with a dehydration air outlet valve and a liquid adding valve, and the two liquid adding valves are both provided with a liquid adding pipe; the dehydration air outlet valve on the first-level purification column is connected to the dehydration air inlet valve of the second-level purification column through the dehydration pipe, and the dehydration air outlet valve on the second-level purification column is connected to the buffer pipe.

[0011] Furthermore, a flow stabilizing valve is provided on the dehydration pipe between the water washing column and the primary purification column, so that the gas can stably enter the primary purification column.

[0012] The beneficial effects of the utility model are as follows: the gas volume and pressure are adjusted by the pressure reducing control valves at the upper and lower ends of the pressure reducer, and then the coal tar, naphthalene, dust and most of the water in the raw coal gas are removed through the water washing column, and the gas is sequentially entered into the first-level purification column, the second-level purification column and the buffer column connected in series through the dehydration pipe. The raw coal gas has a gas dew point lower than -20°C after pretreatment, and does not require cyclone dust removal, turbine water removal and other treatment processes that require electricity and instrument air conditions. The process is simple, the device is compact, and the pretreatment cost is greatly reduced; and the strong dehydration and dust interception capabilities of the first-level purification column and the second-level purification column make it easy and quick to use. The sample gas after pretreatment can be directly measured by a portable composite gas measuring instrument for CO2 and O2 with high analysis frequency, which greatly improves the measurement efficiency and the accuracy of O2 measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0014] Figure 1 It is a schematic diagram of the workflow of the utility model. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] In the description of the present utility model, it should be noted that the terms "upper", "lower", "one side", "one end", "inside", "top", "bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present utility model; the terms "primary" and "secondary" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0017] Since the system for pretreatment of raw coal gas from a Lurgi furnace in the prior art needs to adopt multiple methods for pretreatment, the treatment process is relatively complicated, and requires on-site electricity, instrumentation, wind and other conditions, which is costly; in view of this, the inventors of the present application provide a raw coal gas outlet sample pretreatment device, which can directly use a portable composite gas measuring instrument to directly measure CO2 and O2 with high analysis frequency, greatly improving the measurement efficiency and accuracy of O2 measurement.

[0018] Embodiment 1

[0019] like Figure 1As shown, the pretreatment device for the sample gas at the outlet of the Lurgi furnace raw coal gas comprises a pressure reducer 1, an air inlet pipe 11 is provided on one side of the pressure reducer 1, a pressure reducing pipe 12 is connected to the upper end of the pressure reducer 1, a venting pipeline 13 is provided at the lower end of the pressure reducer 1, a pressure reducing control valve 14 is provided on the venting pipeline 13 and the pressure reducing pipe 12, and a water washing column 2 is connected to one end of the pressure reducing pipe 12; a primary purification column 31 and a secondary purification column 32 are connected in series in sequence on one side of the water washing column 2 through a dehydration pipe 3, a buffer column 4 is connected to the outlet of the secondary purification column 32 through a buffer pipe 41, an exhaust pipe 42 is connected to one side of the buffer column 4, a three-way valve 43 is provided on the exhaust pipe 42, and the exhaust pipe is connected to an analytical instrument through the three-way valve 43.

[0020] Based on the above embodiment, the gas volume and pressure of the raw gas entering the water washing column 2 are adjusted by the pressure reducer 1, so that the pressure of the raw gas entering the water washing column 2 is reduced to 0.01MPa-0.5MPa, the raw gas enters the pressure reducer 1 through the air inlet pipe 11, enters the water washing column 2 through the pressure reducing pipe 12, and the coal tar, naphthalene, dust and most of the water in the raw gas are removed in the water washing column 2, and then the raw gas is allowed to enter the first-level purification column 31 and the second-level purification column 32 connected in series in sequence through the dehydration pipe 3, and the raw gas is removed of water vapor and residual oil, dust and other impurities in the first-level purification column 31 and the second-level purification column 32, and the raw gas in the second-level purification column 32 enters the buffer column 4 through the buffer pipe 41, to ensure that there is no fog before the sample gas enters the analytical instrument; wherein the analytical instrument can be replaced, and the analytical instrument can be replaced with a composite gas measuring instrument, a flow meter, a dew point meter or an Ostwald meter.

[0021] In this embodiment, the two pressure reducing control valves 14 are both spherical valves; a pressure gauge 21 is provided on the pressure reducing pipe 12 , and the pressure gauge 21 is provided between the pressure reducing control valve 14 and the water washing column 2 .

[0022] Among them, the water washing column 2 adjusts the gas volume and pressure through the pressure reducing pipe 12 and the pressure reducing control valve 14 on the venting pipeline 13, and detects the pressure change in the pressure reducing pipe 12 through the pressure gauge 21, so that the pressure of the raw coal gas entering the water washing column 2 is reduced to 0.01MPa-0.75MPa, and preferably the pressure is reduced to 0.1MPa-0.4MPa; the water washing column 2 is a transparent organic glass column with a pressure resistance of 0.5MPa.

[0023] Based on the above embodiment, the pressure reducing pipe 12 is made of Φ6 stainless steel pipe, and the dehydration pipe 3 and the buffer pipe 41 are both made of Φ6 pressure-resistant transparent rubber hose.

[0024] In this embodiment, a water washing air inlet and a drain valve 22 are provided at the bottom end of the water washing column 2, the water washing air inlet is connected to the pressure reducing pipe 12, and the drain valve 22 is connected to a drain pipe 23; a water washing air outlet valve 24 and a water inlet valve 25 are provided at the top end of the water washing column 2, the water washing air outlet valve 24 is connected to the dehydration pipe 3, and a water inlet pipe 26 is provided at the water inlet valve 25.

[0025] Among them, the first-level purification column 31 and the second-level purification column 32 connected in series are both transparent organic glass columns, and the bottom ends of the first-level purification column 31 and the second-level purification column 32 are provided with a dehydration air inlet valve 33 and a drain valve 34, the dehydration air inlet valve 33 is connected to the dehydration pipe 3, and the drain valve 34 is connected to the drain pipe 35; the bottom ends of the first-level purification column 31 and the second-level purification column 32 are provided with a dehydration air outlet valve 36 and a liquid adding valve 37, and the two liquid adding valves 37 are provided with a liquid adding pipe 38; the dehydration air outlet valve 36 on the first-level purification column 31 is connected to the dehydration air inlet valve 33 of the second-level purification column 32 through the dehydration pipe 3, and the dehydration air outlet valve 36 on the second-level purification column 32 is connected to the buffer pipe 41.

[0026] Based on the described embodiment, a steady flow valve 27 is provided on the dehydration pipe 3 between the water washing column 2 and the primary purification column 31, so that the gas can stably enter the primary purification column 31. The primary purification column 31 and the secondary purification column 32 are both organic solvent dehydration columns, wherein the organic solvent is a polyol such as glycerol, ethylene glycol, triethylene glycol, and more preferably triethylene glycol; the water inlet valve 25 is opened to allow the washing liquid to enter the water washing column 2 through the water inlet pipe 26, and the drain valve 22 is opened to allow the washing liquid in the water washing column 2 to flow out through the drain pipe 23; the two liquid adding valves 37 are opened to allow the organic solvent to enter the primary purification column 31 and the secondary purification column 32 respectively through the two liquid adding pipes 38, and the drain valves 34 at the bottom of the primary purification column 31 and the secondary purification column 32 are opened to allow the organic solvent in the primary purification column 31 and the secondary purification column 32 to flow out respectively through the drain pipes 35 connected thereto.

[0027] Completely open the two pressure reducing control valves 14, connect the air inlet pipe 11 to the raw gas sampling point with a quick connector, adjust the gas volume and pressure through the pressure reducing control valves 14 at the upper and lower ends of the pressure reducer 1 and the venting pipeline 13, so that the pressure of the raw gas entering the water washing column 2 is reduced to 0.36MPa; then, the coal tar, naphthalene, dust and most of the water in the raw gas are removed through the water washing column 2; the gas is allowed to enter the first-level purification column 31, the second-level purification column 32 and the buffer column 4 connected in series in turn through the dehydration pipe 3, the flow rate is displayed as 182mL / min, and the outlet dew point is measured by a dew point meter to be -32.3℃.

[0028] Embodiment 2

[0029] The difference between this embodiment and the first embodiment is that: the two pressure reducing control valves 14 are completely opened, the air inlet pipe 11 is connected to the raw gas sampling point by a quick connector, and the gas volume and pressure are adjusted by the pressure reducing control valves 14 at the upper and lower ends of the pressure reducer 1 and the venting pipeline 13, so that the pressure of the raw gas entering the water washing column 2 is reduced to 0.31MPa; then, the coal tar, naphthalene, dust and most of the water in the raw gas are removed by the water washing column 2; the gas is sequentially entered into the first-level purification column 31, the second-level purification column 32 and the buffer column 4 connected in series by the dehydration pipe 3, the flow rate is displayed as 130mL / min, and the outlet dew point is measured by a dew point meter to be -43.6℃.

[0030] Embodiment 3

[0031] The difference between this embodiment and the above two embodiments is that: the two pressure reducing control valves 14 are completely opened, the air inlet pipe 11 is connected to the raw gas sampling point by a quick connector, and the gas volume and pressure are adjusted by the pressure reducing control valves 14 at the upper and lower ends of the pressure reducer 1 and the venting pipeline 13, so that the pressure of the raw gas entering the water washing column 2 is reduced to 0.25MPa; then, the coal tar, naphthalene, dust and most of the water in the raw gas are removed through the water washing column 2; the gas is sequentially entered into the first-level purification column 31, the second-level purification column 32 and the buffer column 4 connected in series through the dehydration pipe 3, and the composite gas measuring instrument is connected to the gas outlet of the buffer column 4. The reading is taken after 1 minute, and the flow rate is displayed as 104mL / min, CO2 is 33.6%, O2 is 0.008%, and the results of the Ostwald instrument are 34.5% and 0.2%, respectively.

[0032] Embodiment 4

[0033] The difference between this embodiment and the above three embodiments is that: the two pressure reducing control valves 14 are completely opened, the air inlet pipe 11 is connected to the raw gas sampling point by a quick connector, and the gas volume and pressure are adjusted by the pressure reducing control valves 14 at the upper and lower ends of the pressure reducer 1 and the venting pipeline 13, so that the pressure of the raw gas entering the water washing column 2 is reduced to 0.32MPa; then, the coal tar, naphthalene, dust and most of the water in the raw gas are removed through the water washing column 2; the gas is sequentially entered into the first-level purification column 31, the second-level purification column 32 and the buffer column 4 connected in series through the dehydration pipe 3, and the composite gas measuring instrument is connected to the gas outlet of the buffer column 4, and the flow rate is displayed as 133mL / min. The reading after 1 minute shows that CO2 is 33.6%, O2 is 0.008%, and the results of the Ostwald instrument are 34.5% and 0.2%, respectively.

[0034] The working principle of the utility model is as follows: open the water inlet valve 25, allow the washing liquid to enter the washing column 2 through the water inlet pipe 26, and close the water inlet valve 25; open two liquid adding valves 37, allow the organic solvent to enter the primary purification column 31 and the secondary purification column 32 respectively through the two liquid adding pipes 38, and close the liquid adding valve 37; connect one end of the air inlet pipe 11 to the crude gas sampling point with a quick connector, allow the crude gas sample to enter the pressure reducer 1 through the air inlet pipe 11, and at the same time adjust the pressure of the crude gas sample entering the washing column 2 through the pressure reducing control valves 14 at the upper and lower ends of the pressure reducer 1 and the venting line 13, and check the pressure value through the pressure gauge 21, so that the crude gas sample enters the washing column 2 through the pressure reducing pipe 12, and remove the coal tar, naphthalene, dust and most of the water in the crude gas sample through the washing liquid in the washing column 2;

[0035] Open the water washing outlet valve 24, the dehydration inlet valve 33 and the dehydration outlet valve 36, so that the sample gas enters the primary purification column 31 and the secondary purification column 32 in sequence through the dehydration pipe 3, and the water vapor and residual oil, dust and other impurities in the raw gas sample are removed by the organic solvent in the primary purification column 31 and the secondary purification column 32; then the raw gas sample in the secondary purification column 32 enters the buffer column 4 through the buffer pipe 41, and the buffer column 4 ensures that there is no fog before the raw gas sample enters the analytical instrument. A part of the raw gas sample in the buffer column 4 is discharged through the exhaust pipe 42, and the other part enters the analytical instrument through the three-way valve 43 on the exhaust pipe 42.

[0036] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pretreatment device for a sample gas at a Lurgi furnace crude gas outlet, comprising a pressure reducer, characterized in that: An air inlet pipe is provided on one side of the pressure reducer, a pressure reducing pipe is connected to the upper end of the pressure reducer, a vent line is provided on the lower end of the pressure reducer, a pressure reducing control valve is provided on the vent line and the pressure reducing pipe, and a water washing column is connected to one end of the pressure reducing pipe; a primary purification column and a secondary purification column are connected in series in sequence on one side of the water washing column through a dehydration pipe, a buffer column is connected to the outlet of the secondary purification column through a buffer pipe, an exhaust pipe is connected to one side of the buffer column, a three-way valve is provided on the exhaust pipe, and the exhaust pipe is connected to an analytical instrument through the three-way valve.

2. The pretreatment device for the sample gas at the outlet of the Lurgi furnace raw gas according to claim 1, characterized in that: The two pressure reducing control valves are both spherical valves; a pressure gauge is provided on the pressure reducing pipe, and the pressure gauge is arranged between the pressure reducing control valve and the water washing column.

3. The pretreatment device for the sample gas at the outlet of the Lurgi furnace raw gas according to claim 2, characterized in that: The water washing column is a transparent organic glass column with a pressure resistance of 0.5 MPa.

4. The pretreatment device for the sample gas at the outlet of the Lurgi furnace raw gas according to claim 3, characterized in that: A water washing air inlet and a drain valve are provided at the bottom end of the water washing column, the water washing air inlet is connected to the pressure reducing pipe, and the drain valve is connected to the drain pipe; a water washing air outlet valve and a water inlet valve are provided at the top end of the water washing column, the water washing air outlet valve is connected to the dehydration pipe, and a water inlet pipe is provided at the water inlet valve.

5. The pretreatment device for the sample gas at the outlet of the Lurgi furnace raw gas according to claim 4, characterized in that: The first-level purification column and the second-level purification column connected in series are both transparent organic glass columns, and the bottom ends of the first-level purification column and the second-level purification column are both provided with a dehydration air inlet valve and a liquid discharge valve, the dehydration air inlet valve is connected to the dehydration pipe, and the liquid discharge valve is connected to the liquid discharge pipe; the bottom ends of the first-level purification column and the second-level purification column are both provided with a dehydration air outlet valve and a liquid filling valve, and the two liquid filling valves are both provided with a liquid filling pipe; the dehydration air outlet valve on the first-level purification column is connected to the dehydration air inlet valve of the second-level purification column through the dehydration pipe, and the dehydration air outlet valve on the second-level purification column is connected to the buffer pipe.

6. The device for pre-treating the sample gas at the outlet of the Lurgi furnace raw gas according to claim 5, characterized in that: A flow stabilizing valve is provided on the dehydration pipe between the water washing column and the primary purification column, so that the gas can stably enter the primary purification column.

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