JP3188060B2 - Sulfurous acid gas sampling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the measurement of sulfur dioxide generated from the PFBC boiler using solid fuels and coal water mixture fuel such as coal, liquid fuel such as heavy oil (hereinafter referred to as SO ₂ gas) The present invention relates to a SO ₂ gas sampling device applied to

[0002]

2. Description of the Related Art Since the two oil shocks, the use of coal has increased as part of the development of alternative energy to petroleum in various countries around the world, and coal-fired fluidized bed combustion furnaces and pressurized coal-fired fluidized bed combustion furnaces ( A pressurized fluidized bed boiler), a pressurized fluidized bed, a spouted bed coal gasifier and the like have been actively studied for practical use.

[0003] Among them, the pressurized fluidized bed boiler has features such as small facilities, low construction cost, in-furnace desulfurization, and improvement in power generation efficiency by combination with a gas turbine. For this reason, it is attracting attention as a boiler that is located very close to development.

[0004] In the pressurized fluidized bed boiler, under high pressure (15
Limestone or dolomite used as a desulfurizing agent at atmospheric pressure) contains CaO as fuel (coal)
It is adjusted so as to be 1 to 2 times the amount of combustible sulfur (S) in the furnace and charged into the furnace, and forms a fluidized bed with air.

[0005] Then, fuel (coal) is supplied into the fluidized bed and burned at an optimum desulfurization temperature of 800 to 900 ° C to fix S compounds generated during the combustion to Ca, thereby performing desulfurization in the furnace. Is going. This desulfurization rate is 95%
That is all.

A conventional flue gas sampling apparatus has been applied to a boiler or the like at normal pressure. After flue gas passes through a filter and a cyclone to remove dust, the spontaneous discharge of piping is performed. It was cooled to around normal temperature by cooling and led to the SO _X meter.

[0007] In the SO _X meter, sampling gas is further cooled to 2 ℃, adjusted to a gas containing 2 ℃ of saturated steam, it was quantified by infrared absorption spectroscopy. 2 ° C
The gas containing saturated water vapor is used to automatically correct the infrared absorption peak due to water vapor which is a harmful component at the time of measuring SO _X.

[0008]

When the conventional gas sampling apparatus is applied to the combustion exhaust gas of a pressurized fluidized bed boiler in a pressurized state, there are the following problems.

(1) When the flue gas is cooled to drain water vapor in the flue gas, SO ₂ is absorbed by the drain. For example, 100 ppm of SO _{2 at} normal pressure and 20 ° C.
While soluble in water at a rate of _{0.0032g · SO 2 / 100g · H} 2 O, SO 2 100p of 16ata, 20 ℃
pm is dissolved in water at a rate of _{0.0505g · SO 2 / 100g · H} 2 O. When the drain precipitates like this,
Since SO ₂ is easily dissolved in water in proportion to the pressure, the measured value of SO ₂ becomes smaller under normal pressure than under normal pressure.

(2) If the flue gas is cooled under pressure and brought to normal pressure, the partial pressure of water vapor in the flue gas may become smaller than the 2 ° C. saturation value. If the partial pressure of water vapor in the combustion exhaust gas is lower than the saturation value of 2 ° C., the infrared light absorption peak due to water vapor in the SO _X meter will not be corrected correctly, and will be measured as a value smaller than the actual SO _X value. . The present invention seeks to solve the above problems.

[0011]

A SO ₂ gas sampling apparatus according to the present invention is a gas sampling probe having a tip inserted into a sampling object containing a high-temperature and high-pressure gas and connected to a first backwash nozzle. A filter provided with a pressure gauge and a differential pressure gauge connected to a second backwash nozzle connected to a valve, a pressure reducing valve connected downstream of the filter, and a device from the gas sampling probe to the pressure reducing valve. A moisture retaining member provided on the outside to keep them warm, a temperature control device provided on the thermal keeping member, a pump connected to the downstream side of the pressure reducing valve for discharging moisture to the outside, and a moisture analyzer connected to a gas analyzer. Unit, and a thermostat in which the unit is stored, and the downstream side of the pressure reducing valve is substantially
It is characterized by being set to atmospheric pressure .

[0012]

In the above, when sampling the high-temperature and high-pressure gas in the sampling object, the second
Gas is supplied from the backwash nozzle of the above, the inside of the filter is set to the same high pressure state as that of the sampling object, and the temperature control device is operated, and the equipment from the gas sampling probe to the pressure reducing valve is the same as the inside of the sampling object. High temperature state.

In this state, when the valve is opened, the high-temperature and high-pressure gas in the object to be sampled is collected by a gas sampling probe with a backwash nozzle and sent to the filter. The high-temperature and high-pressure gas contains ash and limestone particles, some of which accumulate on the probe, which are removed by periodically performing N ₂ purge from the first backwash nozzle, and the particles are removed. Blockage is prevented.

Ash and limestone particles contained in the high-temperature and high-pressure gas that has passed through the gas sampling probe are removed by the filter, and only the gas passes through the filter. The clean gas from which the ash and limestone particles have been removed is reduced in pressure by a pressure reducing valve to a pressure that can be passed through the moisture dehumidification unit, and then supplied to the moisture dehumidification unit which is heated and kept at a constant temperature.

The gas supplied to the moisture dehumidifying unit is separated from the moisture and discharged outside the unit by a pump to be dehumidified. Gas passing through the water dehumidifying unit is supplied to the gas analyzer (SO _X meter) as the sample gas at a constant flow rate, component analysis of the sample gas.

In the above filter, when ash and limestone (fine powder) are deposited and deteriorated in function, the second backwash nozzle causes N ₂ gas to flow back into the filter, and the deposited ash and limestone (fine powder) are removed. ) Is sent back to the inside of the sampling object or the like to restore the function.

As described above, the high-temperature and high-pressure gas in the object to be sampled can be sampled continuously and quickly, and ash and limestone particles are removed under high-temperature and high-pressure.
At high pressures such as the drainage of water vapor condensed during the dehydration operation
For easily dissolved SO ₂ in a constant temperature after pressure reduction by the pressure reducing valve
The dehydration is performed while heating and keeping the temperature, so that ash and limestone deposited in the probe and filter can be easily removed without dissolving SO ₂ in the drain and lowering the analysis accuracy of the sample gas. Implement the device.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, a gas sampling probe 1 with a backwash nozzle inserted into a pressurized fluidized-bed boiler furnace 15 for a sample to be sampled is connected to a ball filling filter 4 via an outlet flange 2 and a ball valve 3 in that order. I have.
The gas sampling probe 1 with a backwash nozzle has a backwash nozzle 1
a, N ₂ gas cylinder is connected (not shown) through a needle valve 1b and N ₂ pipe 1c.

In the ball-filled filter 4, a stainless steel wire mesh 4a is provided at the upper part, and alumina balls 4b (for example, alumina balls having a diameter of 1 mm) are provided at the lower part of the filter.
The plate is filled to a height of 0 mm, and a perforated plate 4c for holding the alumina ball 4b is disposed below the container. further,
On the side of the ball-filled filter 4, alumina balls 4
The differential pressure gauge 4d and the pressure gauge 4e for measuring the pressure loss before and after b
f.

The upper part of the ball-filled filter 4 is
Backwash (gas introduction) nozzle 5c, are connected to the N ₂ gas cylinder (not shown) via a stop valve 5a and N ₂ pipe 5b.

A precision filter 7 equipped with a sintered filter is connected to the outlet of the ball filling filter 4 via a stop valve 6, and further connected to a pressure reducing valve 8.

The gas sampling probe 1 with the backwash nozzle,
The ball valve 3, the ball filling filter 4, the precision filter 7, and the pressure reducing valve 8 are covered with a heat retaining member 9, and the temperature controlling device 10 having a heater is connected to the heat retaining member 9 and is heated to a constant temperature.

A moisture dehumidifying unit 1 is provided at the outlet side of the pressure reducing valve 8.
1 is connected, the moisture dehumidifying unit 11 is composed of a polymer membrane 11a, an air carrier gas generating source pump 11b for exhausting moisture to the outside of the system, and a pipe 11c, and is a thermostat provided with temperature heating means. 11d. Also, the outlet portion of the water dehumidifying unit 11, continuously through a Teflon pipe 11e gas analyzer (SO _X meter) 1
2 are connected.

Next, sampling of gas in a pressurized fluidized bed boiler furnace using the apparatus shown in FIG. 1 will be described below. First, with the pressure reducing valve 8 and the ball valve 2 closed, the needle valve 5a provided on the N ₂ pipe 5b is gradually opened, and nitrogen gas is supplied while watching the pressure gauge 4e to increase the pressure of the sampling system. The pressure in the pressure fluidized bed boiler furnace 15 is made to match.

Thereafter, the heat retaining member 6 is heated by the temperature controller 10, and the water is condensed by the temperature of the gas sampling probe 1 with the backwash nozzle, the ball valve 3, the ball filling filter 4, the precision filter 7, and the pressure reducing valve 8. And the temperature of the thermostat 11d in which the moisture dehumidifying unit 11 is inserted is heated to a usable temperature of the polymer film 11a,
The pump 11b and the gas analyzer 12 are operated.

Next, the ball valve 3 and the stop valve 6
Fully open and pressurize the gas in the pressurized fluidized bed boiler furnace at high temperature and pressure.
In is passed through the ball filling filter 4 in and fine-filter 7, the pressure reducing valve 8 the pressure was reduced to atmospheric pressure, is passed through the water dehumidifying unit 11 at a gas flow rate of 1-3 l / min, the gas analyzer 12 Stable supply.

When the gas in the pressurized fluidized-bed boiler furnace is passed through the gas sampling device, the ash and limestone contained in the gas are removed by the gas sampling probe 1 having a backwash nozzle and the alumina balls 4b in the ball filling filter 4. The gas that has accumulated in between and has been removed from ash and limestone in a fine powder state passes through the ball filling filter 4.

The function deterioration of the ball-filled filter 4 is caused by the dense accumulation of dust between the alumina balls 4b. This is because the differential pressure indicated by the differential pressure gauge 4d connected before and after the alumina ball 4b layer rapidly increases. Can be determined.

For the ball-filled filter 4 whose function has been reduced, the stop valve 6 is closed, the stop valve 5a is opened, and the nitrogen gas is back-flushed from the N ² cylinder into the nozzle 5.
By returning the collected ash and limestone (fine powder) into the pressurized fluidized-bed boiler furnace 15 by returning the collected ash and limestone (fine powder) to the state before the collection, the function can be restored.

The gas that has passed through the ball-filled filter 4 is sent to the precision filter 7 and
The ultrafine ash and limestone that have passed without being removed are removed by the precision filter 7. When the function of the precision filter 7 deteriorates, the function of the precision filter 7 can be maintained by replacing the sintered filter provided in the precision filter 7 with a new one.

The gas that has passed through the precision filter 7 under high temperature and high pressure passes through a pressure reducing valve 8 into a moisture dehumidifying unit 11.
Pressure, here gas analyzer (SOx meter)
After the pressure is reduced to approximately atmospheric pressure from the point of supply to 12, it is heated and kept at a constant temperature (below the operating limit temperature of the moisture dehumidifying unit)
Supplied to the moisture dehumidification unit 11
Only the moisture is forcibly separated by the polymer film 11a in 1 and discharged out of the unit 11 by the air carrier gas supplied by the pump 11b to perform dehumidification.

The dehumidifying ability of the moisture dehumidifying unit 11 is as follows:
Because it is proportional to the volume of the polymer membrane and inversely proportional to the gas flow rate,
In selecting the moisture dehumidifying unit 11, temperature, flow rate,
It is necessary to carefully consider the volume and the like. The moisture dehumidifying unit 11 is sold under the trade name of Perm Pure Dryer.

The gas passing through the moisture dehumidifying unit 11 is supplied to a gas analyzer (SO
_{An X} meter 12 is supplied as a sample gas, and a component analysis of the sample gas is performed.

As described above, the exhaust gas from the pressurized fluidized-bed boiler is sampled under high temperature and high pressure, and ash and limestone are sampled under high temperature and high pressure.
The particles are removed.
Easy therefore reduced dissolved SO ₂ in the drain of condensed water vapor
After depressurizing with a pressure valve, dehydration is performed while heating and keeping it at a constant temperature.
Therefore, it is possible to purify continuously and quickly,
Further, it is possible to efficiently discharge the water out of the system, to introduce the gas into the analyzer while preventing the SO ₂ gas from being drained, and to further reduce ash and ash generated when purifying the exhaust gas from the pressurized fluidized-bed boiler. Since limestone can be unmanned and efficiently sent back from the sampling device to the pressurized fluidized-bed boiler furnace, there is no need to dispose of ash and limestone.

[0035]

According to the SO ₂ gas sampling apparatus of the present invention, a valve is provided between a gas sampling probe and a gas analyzer inserted into a sampling object containing a high-temperature and high-pressure gas.
A filter, a pressure reducing valve, and a moisture dehumidifying unit are sequentially connected, a heat retaining member provided with a temperature control device is provided outside the device from the gas sampling probe to the pressure reducing valve, and the moisture dehumidifying unit is housed in a thermostat, A backwash nozzle is connected to the gas sampling probe and the filter.
By thus constructed is set in the high-temperature, high-pressure gas in the sampling object can be continuously and rapidly sampled, ash and limestone particles under high temperature and high pressure
After removal, the pressure was reduced by a pressure reducing valve, and the temperature was maintained at a constant temperature by heating.
Since dehydration is performed in a state, SO ₂ is not dissolved in the drain, and the analysis accuracy of the sample gas is not reduced. Thus, an apparatus that can easily remove ash and limestone deposited in the probe and the filter is realized. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an SO ₂ gas sampling device according to one embodiment of the present invention.

[Explanation of symbols]

1 Gas sampling probe 1a backwash nozzle 1b needle valve 1c N ₂ pipe 2 flange 3 Ball valve 4 balls filled filter 4a stainless steel wire mesh 4b alumina balls 4c perforated plate 4d differential pressure gauge 4e manometer 4f pipe 5a stop valve 5b N ₂ pipe 5c Backwash nozzle 6 Stop valve 7 Precision filter 8 Pressure reducing valve 9 Heat retaining member 10 Temperature controller 11 Water dehumidifying unit 11a Polymer membrane 11b Pump 11c Piping 11d Constant temperature bath 11e Teflon piping 12 Gas analyzer 15 Pressurized fluidized bed boiler furnace

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 1/22 G01N 1/00 101

Claims (1)

(57) [Claims] 1. A gas sampling probe having a tip inserted into a sampling object containing a high-temperature and high-pressure gas and having a first backwash nozzle connected thereto, and a second backwash nozzle connected to the probe via a valve. A filter provided with a pressure gauge and a differential pressure gauge connected thereto, a pressure reducing valve connected downstream of the filter, a heat retaining member provided outside the device from the gas sampling probe to the pressure reducing valve to keep them warm, a heat retaining member for the same a temperature regulating device provided, equipped with a water dehumidifying unit, and a thermostat which the unit is housed gas analyzer pump is provided for discharging the connected water downstream to the outside is connected to the pressure reducing valve The downstream side of the pressure reducing valve is substantially
Sulfurous acid gas sampling device characterized by being set to atmospheric pressure .