CN209784284U - A sampling device for detecting components of coke oven flue gas - Google Patents

Abstract

The utility model relates to a sampling device used in the detection of the components of the flue gas of a coke oven, which comprises a sampling gun, three sampling units, a voltage stabilizing unit, a mass flow controller and a DCS control system; a sampling pipe in the sampling gun is connected with three sampling units through an electric control four-way valve, and the three sampling units are provided with 3 sampling branches which are respectively a solid-liquid phase sampling branch, a dry gas sampling branch and an acid gas sampling branch; the three sampling units are sequentially connected with the voltage stabilizing unit and the mass flow controller through a four-way valve; and detection and control elements in the sampling gun, the three sampling units, the voltage stabilizing unit and the mass flow controller are respectively connected with the DCS control system. The utility model discloses an adopt single unit device to carry out the purpose of accurate high-efficient sampling respectively to coke oven flue waste gas solid-liquid phase composition, acid gas composition, dry gas, simple structure, the function is various, convenient operation.

Description

A sampling device for detecting components of coke oven flue gas

technical field

The utility model relates to the technical field of on-line detection of coke oven flue gas, in particular to a sampling device suitable for detecting components of coke oven flue gas by using a GC-MS method or an IC method.

Background technique

At present, the sampling methods used for online detection of coke oven flue gas components mainly include the following:

(1) The traditional sampling device mentioned in "GBT 16157-1996 Sampling Method for Particulate Matter and Gaseous Pollutants in Exhaust from Stationary Pollution Sources", the device is characterized by the ability to calculate the moisture content in the gas more accurately; its disadvantage lies in: the structure of the device Complicated, inconvenient to use, long preparation time before use, many connected devices may easily lead to air leakage, and insufficient accuracy; at the same time, acid gases such as SO ₂ in the coke oven flue gas will directly dissolve in the cooling water and cause acid gases The analytical values are invalid, and the use of a single glass fiber as a solid-liquid phase adsorbent in gas results in low adsorption performance, etc.

(2) "HJT 56-2000 Determination of Sulfur Dioxide in Exhaust from Stationary Pollution Sources by Iodometric Method", "HJT 43-1999 Determination of Nitrogen Oxide in Exhaust from Stationary Pollution Sources by Spectrophotometric Method of Naphthaleneethylenediamine Hydrochloride", etc. use chemical solution absorption The sampling method proposed in the environmental test standard for specific gases is characterized by accurate quantitative sampling of specific gases; its disadvantage is that it has a single function and cannot sample the solid-liquid phase components in the flue gas, and the device needs to be vacuumed in advance. The operation is complicated; the iodine measurement method of sulfur dioxide has poor absorption performance and poor stability after absorption.

(3) "HJ 629-2011 Determination of Sulfur Dioxide in Stationary Pollution Source Exhaust Gas by Non-dispersive Infrared Absorption Method", "HJT 57-2000 Determination of Sulfur Dioxide in Stationary Pollution Source Exhaust Gas by Constant Potential Electrolysis", "HJ 692-2014 Stationary Pollution Source Exhaust Gas Nitrogen Oxidation Non-dispersive infrared absorption method for the determination of pollutants", "HJ 693-2014 Determination of nitrogen oxides in fixed pollution sources by constant potential electrolysis" and other environmental test standards that use direct reading of the instrument The sampling function that comes with the analytical instrument is characterized in that it can The test concentration can be directly read out through the instrument, no preparation in advance is required, and the sampling result is stable. The disadvantage is that the collected sample can only be used by the instrument, and the sample cannot be kept for storage. It is not possible to sample the solid and liquid phase components in the flue gas. Even if the heating pipeline is used, The high-humidity flue gas will still condense in the dryer, Patil cooler and other parts, and then absorb _acid gases such as SO2, resulting in deviations in the analysis of acid gas components.

Contents of the invention

The utility model provides a sampling device for detecting the components of coke oven flue gas, which can accurately collect the solid-liquid phase components in the coke oven flue gas, which is convenient for analysis by GC-MS method; Accurately collect SO ₂ and oxidize it into SO ₄ ^2- ions for stable storage, which is convenient for analysis by IC method; The purpose of accurate and efficient sampling of components and dry gases respectively is simple in structure, diverse in function and convenient in operation.

In order to achieve the above object, the utility model adopts the following technical solutions to realize:

A sampling device for detecting components of coke oven flue gas, comprising a sampling gun, a three-way sampling unit, a voltage stabilizing unit, a mass flow controller and a DCS control system; the sampling pipe in the sampling gun passes through an electronically controlled four-way The valve is connected to the three-way sampling unit, and the sampling pipe is equipped with an ultrasonic flowmeter; the three-way sampling unit is equipped with three sampling branches, which are respectively solid-liquid phase sampling branch, dry gas sampling branch and acid gas sampling branch. A solid-liquid sampling pipe is set on the solid-liquid sampling branch, a Peltier cooler is arranged on the outside of the solid-liquid sampling pipe, a double absorption bottle group is set on the acid gas sampling branch, and three sampling branches Check valves are installed at the ends of the air flow; the three-way sampling unit is connected to the inlet end of the voltage stabilizing unit through a four-way valve, the outlet end of the voltage stabilizing unit is connected to the mass flow controller, and the outlet end of the mass flow controller can be connected to the sampling air bag; The detection and control elements in the sampling gun, the three-way sampling unit, the voltage stabilizing unit and the mass flow controller are respectively connected with the DCS control system.

The sampling gun is composed of a sampling tube, a first thermocouple, a first heating band and a second thermocouple; the first thermocouple is arranged at the inlet end of the sampling tube, and the second thermocouple is arranged at the upstream of the ultrasonic flowmeter. The sampling pipe is arranged close to the ultrasonic flowmeter, and the sampling pipe, the first thermocouple and the second thermocouple located outside the ultrasonic flowmeter are covered by the first heating tape; the ultrasonic flowmeter, the first thermocouple, the second The controllers of the second thermocouple and the first heating belt are respectively connected to the DCS control system.

The solid-liquid phase sampling tube is provided with three sections of packing, along the flow direction of the sample gas, the first section is filled with glass fiber cotton, the second section is filled with activated carbon, and the third section is filled with macroporous adsorption resin.

The double absorption bottle group is composed of two absorption bottles connected in sequence, and each absorption bottle is filled with a mixed absorption solution of hydrogen peroxide and triethanolamine.

The sample gas delivery pipeline between the electronically controlled four-way valve and the solid-liquid phase sampling pipe, and the sample gas delivery pipeline between the electronically controlled four-way valve and the double absorption bottle group are respectively provided with a second heating zone, and the second The controller of the heating belt is connected with the DCS control system.

The voltage stabilizing unit is composed of a front stabilizing tank, an air pump and a rear stabilizing tank, which are sequentially arranged on the sample gas delivery pipeline along the air flow direction, and an electric pressure gauge is arranged on the rear stabilizing tank, and the air pump and the electric pressure gauge are respectively connected with the DCS control system is connected.

A third thermocouple is arranged on the sample gas delivery pipeline upstream of the mass flow controller, and the third thermocouple is connected with the DCS control system.

Compared with the prior art, the beneficial effects of the utility model are:

1) Accurate and efficient sampling of solid-liquid phase components, acid gas components, and dry gas in coke oven flue gas by using a single device to achieve functional diversification;

2) All the sampling pipelines in the front section are wrapped with heating tape to prevent the temperature of the high-humidity flue gas from being lower than the dew point. After the condensed water is precipitated, it absorbs acid gases such as SO ₂ and causes deviations in the exhaust gas analysis results;

3) The solid-liquid phase sampling adopts a three-stage packing solid-liquid phase sampling tube, which is cooled by a Peltier cooler at the same time, which greatly improves the sampling efficiency compared with the traditional glass fiber membrane sampling tube;

4) Acidic gas sampling uses alkaline system oxidation reagents, taking SO ₂ as an example. Compared with the instrument method, the utility model can absorb the sulfurous acid generated in the sample gas delivery pipeline, ensuring that the analysis results will not be affected by condensed water. Compared with the method in "HJT56-2000 Iodometric Method for Determination of Sulfur Dioxide in Exhaust from Fixed Pollution Sources", the utility model captures sulfur dioxide in the form of stable sulfate ions instead of unstable sulfite, and the absorption efficiency of the absorption liquid is more efficient , the used absorption solution can be stored stably;

5) For dry gas, this device can accurately measure the sampled gas, and can use containers such as sampling air bags to store the sampled gas.

Description of drawings

Fig. 1 is a structural schematic diagram of a sampling device used for detecting components of coke oven flue gas described in the present invention.

Fig. 2 is a schematic structural view of the solid-liquid phase sampling tube of the present invention.

In the figure: 1. The first thermocouple 2. Sampling pipe 3. The first heating belt 4. Ultrasonic flowmeter 5. Peltier cooler 6. Solid-liquid phase sampling pipe 61. Glass fiber cotton packing 62. Activated carbon packing 63. Macroporous adsorption resin filler 7. Check valve 8. Double absorption bottle group 9. Front surge tank 10. Rear surge tank 11. Electric pressure gauge 12. Mass flow controller 13. Air pump 14. DCS control system 15. Section Second thermocouple 16. Third thermocouple 17. Electric control four-way valve 18. Second heating belt

Detailed ways

The specific embodiment of the utility model will be further described below in conjunction with accompanying drawing:

As shown in Figure 1, a sampling device for detecting coke oven flue gas components described in the present invention includes a sampling gun, a three-way sampling unit, a voltage stabilizing unit, a mass flow controller 12 and a DCS control system 14; The sampling pipe 2 in the sampling gun is connected to the three-way sampling unit through an electronically controlled four-way valve 17, and the sampling pipe 2 is provided with an ultrasonic flowmeter 4; the three-way sampling unit is provided with 3 sampling branches, and the 3 sampling branches are respectively Solid-liquid phase sampling branch, dry gas sampling branch and acid gas sampling branch; solid-liquid phase sampling pipe 6 is set on the solid-liquid phase sampling branch, and Peltier cooler 5 is set on the outside of solid-liquid phase sampling pipe 6 , the acid gas sampling branch is provided with double absorption bottle groups 8, and the gas flow ends of the 3 sampling branches are respectively provided with check valves 7; the three-way sampling unit is connected to the air inlet of the voltage stabilizing unit through a four-way valve, and the voltage stabilizing unit The air outlet of the mass flow controller 12 is connected to the mass flow controller 12, and the air outlet of the mass flow controller 12 can be connected to the sampling air bag; the detection and control elements in the sampling gun, the three-way sampling unit, the voltage stabilizing unit, and the mass flow controller 12 are respectively connected with the DCS The control system 14 is connected.

Described sampling gun is made up of sampling tube 2, the first thermocouple 1, the first heating band 3 and the second thermocouple 15; Set on the sampling pipe 2 upstream of the ultrasonic flowmeter 4 and close to the ultrasonic flowmeter 4, the sampling pipe 2 outside the ultrasonic flowmeter 4, the first thermocouple 1 and the second thermocouple 15 are all heated by the first heating belt 3 Coating; the controllers of the ultrasonic flowmeter 4 , the first thermocouple 1 , the second thermocouple 15 and the first heating belt 3 are respectively connected to the DCS control system 14 .

As shown in Figure 2, the solid-liquid phase sampling pipe 6 is provided with three sections of packing, along the flow direction of the sample gas, the first section is glass fiber cotton packing 61, the second section is activated carbon packing 62, and the third section is a large hole Adsorption resin filler 63.

The double absorption bottle group 8 is composed of two absorption bottles connected in sequence, and each absorption bottle is filled with a mixed absorption solution of hydrogen peroxide and triethanolamine.

The sample gas delivery pipeline between the electronically controlled four-way valve 17 and the solid-liquid phase sampling pipe 6, and the sample gas delivery pipeline between the electronically controlled four-way valve 17 and the double absorption bottle group 8 are respectively provided with second heating The belt 18, the controller of the second heating belt 18 is connected with the DCS control system 14.

The voltage stabilizing unit is composed of a front surge tank 9, an air pump 13 and a rear surge tank 10 which are sequentially arranged on the sample gas delivery pipeline along the air flow direction. The rear surge tank 10 is provided with an electric pressure gauge 11, and the air pump 13 And the electric pressure gauge 11 is connected with the DCS control system 14 respectively.

A third thermocouple 16 is provided on the sample gas delivery pipeline upstream of the mass flow controller 12 , and the third thermocouple 16 is connected to the DCS control system 14 .

The sampling device used for detecting coke oven flue gas components described in the utility model adopts an electronically controlled four-way valve 17 to realize function switching, and uses a flow meter, a thermocouple and a DCS control system 14 to cooperate to control the flow rate of the sampling gas. The solid-liquid phase sampling tube 6, absorption bottle or sampling air bag are used to collect different sampling materials respectively, and the pressure of the pressure-stabilizing tank 10 is controlled by the interlocking of the air pump 13 and the electric pressure gauge 11, so that the coke oven flue gas Accurate and quantitative collection of solid and liquid phase components, SO ₂ in wet flue gas and dry gas. The utility model effectively solves the problems of the existing sampling device such as single function, low sampling efficiency, and low stability of absorbing samples, and has important application value for sampling and analyzing coke oven flue gas.

Explanation of related terms:

GC-MS: Gas chromatography-mass spectrometry, an instrument that combines a gas chromatograph and a mass spectrometer.

IC: Ion chromatography, which uses low-capacity ion-exchange resin as a fixed relative ionic substance for separation. The IC method is a chromatographic method that uses a conductivity detector to continuously detect the change in the conductance of the effluent.

DCS control system: Distributed control system, English abbreviation Distributed Control System, also known as distributed control system in the domestic automatic control industry. It is a new type of computer control system relative to the centralized control system.

Peltier cooler: A cooler that uses the principle that materials with thermoelectric energy conversion properties have cooling effects when passing direct current.

The first thermocouple 1, the second thermocouple 15, and the third thermocouple 16 are respectively connected in communication with the DCS control system 14, and their temperature information is displayed, calculated and stored by the DCS control system; the ultrasonic flowmeter 4 is connected in communication with the DCS control system 14 , the flue gas flow data is displayed, calculated and stored by the DCS control system 14; the electronically controlled four-way valve 17 communicates with the DCS control system 14, and its opening data is displayed, controlled and stored by the DCS control system 14; the first heating zone 3. The controllers of the second heating belt 18 are connected in communication with the DCS control system 14 respectively, and its temperature information is displayed, controlled and stored by the DCS control system 14; the air pump 13 is connected in communication with the DCS control system 14, and its speed information is controlled by the DCS control system 14 display, control, and storage; the electric pressure gauge 11 installed on the rear surge tank 10 communicates with the DCS control system 14, and its pressure information is displayed, calculated, and stored by the DCS control system 14; the mass flow controller 12 communicates with the DCS control system 14 communication connection, the flow information of which is displayed, controlled, calculated and stored by the DCS control system 14.

In Figure 1, FE marked on the ultrasonic flowmeter and mass flow controller is the abbreviation of fluid estimate, which means that the device can measure the flow of fluid flowing through it; FC marked on the mass flow controller is fluid control, which means that the device can Control the flow of fluid flowing through; the ultrasonic flowmeter is marked with FE, which means it can measure the flow rate, and the mass flow controller is marked with FE and FC, which means it can measure and control the flow rate, which is a conventional marking method in this field .

The following examples are carried out on the premise of the technical solution of the utility model, and detailed implementation and specific operation process are provided, but the protection scope of the utility model is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

【Example 1】

In this embodiment, the sampling gas is flue gas from a small coke oven flue gas in a certain factory, the sampling flow rate is 1L/min, and the sampling time is 6h. The control of the sampling flow rate is realized by controlling the gas pump 13 of the DCS control system. solid-liquid phase components. The sampling process is as follows:

The DCS control system 14 controls the switching of the electronically controlled four-way valve 17, so that the gas outlet end of the sampling pipe 2 communicates with the solid-liquid phase sampling branch. The heating temperature of the belts 18 is controlled by the DCS control system 14 respectively. Start the air pump 13 when sampling, and the flue gas flows along the sampling pipe 2 through the ultrasonic flowmeter 4 and the electronically controlled four-way valve 17 to the solid-liquid phase sampling pipe 6, and is cooled by the Peltier cooler 5 when it flows through the solid-liquid phase sampling pipe 6. After cooling, the solid-liquid phase components in the flue gas are captured by the three-stage packing 61, 62, 63, and the remaining gas is discharged from the gas outlet of the mass flow controller 12 after passing through the four-way valve and the pressure stabilizing unit.

The detection information is transmitted to the DCS control system 14 through the second thermocouple 15 and the ultrasonic flowmeter 4, and the total sampling flow is obtained after integral calculation. The solid-liquid phase components captured by the three-stage packing were subjected to Soxhlet extraction with carbon disulfide, and analyzed by GC-MS.

[Example 2]

In this embodiment, the sampling gas is water-containing simulated flue gas, the sampling flow rate is 1 L/min, and the sampling time is 20 min. The sampling flow rate is controlled by the DCS control system 14 to control the air pump 13. The purpose of sampling is to collect sulfur dioxide in the flue gas. The sampling process is as follows:

The DCS control system 14 controls the switching of the electronically controlled four-way valve 17 so that the gas outlet end of the sampling pipe 2 communicates with the acid gas sampling branch. During the adoption process, the heating temperature of the first heating belt 3 and the second heating belt 18 located on the acid gas sampling branch road are respectively controlled by the DCS control system 14 . When sampling, start the air pump 13, and the flue gas flows along the sampling pipe 2 through the ultrasonic flowmeter 4 and the electronically controlled four-way valve 17 to the double absorption pipe group 8, which is composed of two 75ml absorption bottles connected in series, 2 Each absorption bottle is equipped with 35ml of absorption liquid, the absorption liquid is a mixed aqueous solution of 3% hydrogen peroxide and 3% triethanolamine, the sulfur dioxide component in the flue gas is captured by the absorption liquid in the absorption bottle, and the remaining gas passes through four After passing through the valve and the pressure stabilizing unit, it is discharged from the gas outlet of the mass flow controller 12.

The detection information is transmitted to the DCS control system 14 through the second thermocouple 15 and the ultrasonic flowmeter 4, and the total sampling flow is obtained after integral calculation. After collecting sulfur dioxide in the absorption solution, use a 500ml volumetric flask to make up the volume, draw 10ml and analyze it by IC method.

[Example 3]

In this embodiment, the sampling gas is anhydrous simulated flue gas, and the purpose of sampling is to accurately measure a certain volume of sample gas. The sampling process is as follows:

The DCS control system 14 controls the switching of the electronically controlled four-way valve 17, so that the gas outlet end of the sampling pipe 2 communicates with the dry gas sampling branch. When sampling, start the air pump 13, and the flue gas flows along the sampling pipe 2 through the ultrasonic flowmeter 4, the electronically controlled four-way valve 17, and the four-way valve directly to the voltage stabilizing unit. The rear surge tank 10 is interlocked and controlled by the air pump 13, the electric pressure gauge 11 and the DCS control system 14 to keep the pressure at 0.3Mpa. The stabilized flue gas is controlled by the mass flow controller 12 to flow into the sampling air bag.

The detection information is transmitted to the DCS control system 14 through the third thermocouple 16 and the mass flow controller 12, and the total sampling flow is obtained after integral calculation.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto. The equivalent replacement or change of the new technical solution and the concept of the utility model shall be covered by the protection scope of the utility model.

Claims (7)

1. A sampling device used when detecting coke oven flue gas components, is characterized in that, comprises sampling gun, three-way sampling unit, voltage stabilizing unit, mass flow controller and DCS control system; The sampling in described sampling gun The tube is connected to the three-way sampling unit through an electronically controlled four-way valve, and the sampling tube is equipped with an ultrasonic flowmeter; the three-way sampling unit is equipped with three sampling branches, and the three sampling branches are respectively solid-liquid phase sampling branch and dry gas sampling branch. road and acid gas sampling branch; the solid-liquid sampling branch is provided with a solid-liquid sampling pipe, the outside of the solid-liquid sampling pipe is provided with a Peltier cooler, and the acid gas sampling branch is provided with a double absorption bottle group, The air flow ends of the three sampling branches are respectively equipped with check valves; the three-way sampling unit is connected to the inlet end of the voltage stabilizing unit through the four-way valve, the outlet end of the voltage stabilizing unit is connected to the mass flow controller, and the gas outlet end of the mass flow controller is The sampling air bag can be connected; the detection and control elements in the sampling gun, three-way sampling unit, voltage stabilizing unit, and mass flow controller are respectively connected with the DCS control system. 2. The sampling device used when detecting coke oven flue gas components according to claim 1, wherein the sampling gun is composed of a sampling tube, a first thermocouple, a first heating band and a second thermocouple Composition; the first thermocouple is arranged at the inlet end of the sampling pipe, the second thermocouple is arranged on the sampling pipe upstream of the ultrasonic flowmeter and is set close to the ultrasonic flowmeter, the sampling pipe outside the ultrasonic flowmeter, the first Both the thermocouple and the second thermocouple are covered by the first heating belt; the controllers of the ultrasonic flowmeter, the first thermocouple, the second thermocouple and the first heating belt are respectively connected to the DCS control system. 3. The sampling device used when detecting coke oven flue gas components according to claim 1, wherein three sections of packing are arranged in the solid-liquid phase sampling pipe, and along the flow direction of the sample gas, the first section is Glass fiber cotton filler, the second section is activated carbon filler, and the third section is macroporous adsorption resin filler. 4. a kind of sampling device when detecting coke oven flue gas composition according to claim 1, is characterized in that, described double absorbing bottle group is made up of 2 absorbing bottles that connect successively, each absorbing bottle Filled with hydrogen peroxide and triethanolamine mixed absorption liquid. 5. A sampling device for detecting coke oven flue gas components according to claim 1, characterized in that, the sample gas delivery pipeline between the electronically controlled four-way valve and the solid-liquid phase sampling pipe, A second heating zone is respectively arranged on the outside of the sample gas delivery pipeline between the electronically controlled four-way valve and the double absorption bottle group, and the controller of the second heating zone is connected with the DCS control system. 6. A sampling device for detecting the components of coke oven flue gas according to claim 1, wherein the pressure stabilizing unit consists of a front surge tank which is sequentially arranged on the sample gas delivery pipeline along the airflow direction , an air pump and a rear pressure-stabilizing tank, and an electric pressure gauge is installed on the rear pressure-stabilizing tank, and the air pump and the electric pressure gauge are respectively connected with the DCS control system. 7. The sampling device for detecting components of coke oven flue gas according to claim 1, wherein a third thermocouple is set on the sample gas delivery pipeline upstream of the mass flow controller, and the third thermocouple Even connected with the DCS control system.