JPS5885137A - Measuring apparatus for concentration of carbon monoxide gas in gas including coal dust - Google Patents

Abstract

PURPOSE:To prevent a transmitting film from choking due to filtering of the fluid including a large quantity of coal dust and much moisture by providing the transmitting film at the part where carbon monoxide gas outside a receptacle is introduced. CONSTITUTION:A transmitting film 8 is provided at the part where carbon monoxide gas is introduced of carbon monoxide gas concentration measuring apparatus 5 which measures carbon monoxide gas concentration with the carbon monoxide gas introduced into a receptacle 7 having a measuring instrument therein. The carbon monoxide in the fluid is introduced into the receptacle 7, passing through the transmitting film 8 and is measured by a detecting part 10 to detect the carbon monoxide concentration in the fluid. In the present invention, the film is free from choking because the concentration of the carbon monoxide passed through the transmitting film is directly measured by a transmitting action without filtering the fluid including coal dust and water content or without providing a moisture removal apparatus as in a conventional apparatus.

Description

[Detailed Description of the Invention] A device for measuring carbon monoxide gas concentration in a fluid flowing through a combustion pulverized coal supply system or a combustion exhaust gas system, etc., which contains a certain amount of moisture, and in particular, measures the carbon monoxide gas concentration through a permeable membrane. This invention relates to a simple device for measuring the concentration of carbon monoxide gas in a fluid containing coal dust, which does not cause clogging of the measuring device.

Recently, the use of coal-fired boilers in thermal power plants has been increasing from the perspective of saving oil resources, and the combustion equipment of these boilers includes pulverized coal mills that pulverize the coal to burn it efficiently. Widely used. However, due to the lack of suitable cooling equipment, the combustible gases generated in the pulverized coal mill, mainly carbon monoxide gas, can cause explosions. The conventionally used carbon monoxide concentration measuring device and its problems will be described below.

Figure 1 shows an apparatus for measuring the concentration of carbon monoxide in a fluid that does not contain dust or moisture. In this device, a container (6) having an opening is attached to the side wall of a tact (α), a slit (c) is provided at the entrance of the opening, and a measuring device (d) is placed inside the container (b).
) are arranged. Carbon monoxide gas in the fluid flowing in the direction of arrow e in the duct (α) passes through the slit (c) and enters the container (b), where the gas concentration is measured, but the situation changes and dust particles are present in the fluid. When the water content increases, the slit (c) becomes blocked and measurement becomes impossible.

FIG. 2 shows the measuring device when there is relatively little dust and moisture. This device has a sampling port (
A measuring device (d) is provided through a filter (g), a dryer (or dehumidifier) (h), and a suction device (1) as shown in the figure
is arranged. This device has a pulverized coal concentration of approximately 0.
When installed at the exit tact of an 8 Kf//m9 pulverized coal mill, it will cause blockage in about 30 seconds.

Figure 6 shows an improved version of Figure 2, with filter (g)
A heater (j) and a cooler (k) are provided on the inlet side of the fluid to remove moisture from the fluid. This type also has the disadvantage that the filter medium is subject to clogging, and carbon monoxide scum is newly generated during the heating process, which hinders accurate measurement.

The present invention eliminates the above-mentioned drawbacks, makes it possible to accurately measure the concentration of carbon monoxide residue in a fluid containing a large amount of dust and a considerable amount of water without causing clogging, and moreover, the fluid velocity is A device that accepts raw scum and measures the scum concentration, which was created for the purpose of providing a simple device for measuring the concentration of carbon monoxide gas in gas containing coal dust, which enables measurement even when the gas is large or there are slight pressure fluctuations. This carbon oxide residue concentration measuring device is characterized in that a permeable membrane is provided at a portion into which carbon monoxide residue outside the container is introduced.

Embodiments of the present invention will be described below based on the drawings.

In Figures 4 to 7, code (1) is a pulverized coal mill;
(2) is coal input (injected from the direction of arrow m), (3)
is the air and water vapor supply pipe (inflow from the direction of arrow n), (
4) is an exit tact, and a carbon oxide residue concentration measuring device (hereinafter referred to as the measuring device) (5) is connected to an exit tact I (4).
) is attached to the side wall of the The coal pulverized by the pulverized coal mill (1) flows in the direction of arrow p along with the air flow flowing upward inside the outlet tact (4) by pressurization or depressurization.
It is transported to the coal burning section or coal storage section. The pressure inside the exit tact varies depending on the location of the fan and the transport distance, but is approximately several hundred cubic meters of water.

As shown in Fig. 7, the measuring device (5) consists of a container (7) having a mounting flange (6), a permeable membrane (8) attached to the inlet of the container (7), and a permeable membrane (8). It consists of a supporting perforated plate (9), a detection part (10) for measuring waste concentration placed inside the container (7), a waste regulator for ventilation (11), etc. A ventilation chamber 04) having a gap of about 3.5 mm is formed between the front surfaces (I3). In addition, a communication pipe (15) and a gas discharge pipe 06) connecting to the ventilation room (the old ventilation gas regulator for 1 loss) are installed, and a valve 07) (18) is installed on each pipe side 06). spring.

The permeable membrane (8) is made of, for example, silicone or a silicone-polycarbonate copolymer and has a thickness of 0.1 to 0.00 mm.
This is a film formed on n. In addition, when the thickness is set to 0.01 mm or less, a porous Teflon membrane is provided on the rear surface side (detection section side) of the permeable membrane (8) to reinforce it, or it is attached to the front surface 03) of the detection section 00).

The detection unit OO) for gas concentration measurement uses a semiconductor sensor for -carbon oxide scum. This sensor has a detection part 00
) applies the principle that the electrical conductivity changes when carbon monoxide scum is adsorbed on the surface of the sensor.The change in signal current generated by the sensor is extracted to the outside via the coat α9), and the measured value is displayed on a display (not shown). Display. A commercially available semiconductor sensor is used.

The ventilation waste controller (11) controls the ventilation room (11) at regular intervals.
4) Used for ventilation.

Next, the operation of this device will be explained. First, the ventilation room (1 =
1) After ventilating the inside, close valves 07)1.8). Here, the carbon monoxide residue in the fluid passes through the permeable membrane (8) (gas dissolves in the membrane, passes through the membrane and evaporates to the opposite side of the membrane, and the gas passes through as a whole) The gas concentration is detected by the detection unit (10) and measured. Refuse regulator for ventilation after a certain period of time (1
1) to ventilate, and then use the ventilation scum regulator (11
), close the valve outlet (I8), and measure the carbon monoxide scum concentration again. The above measurements are repeated at regular intervals, that is, every several minutes to more than ten minutes. This time is appropriately adjusted depending on the type and thickness of the permeable membrane (8).

The ventilation room (14) will be ventilated before measurement.
4) Since the concentration of carbon monoxide gas in the container (7) becomes zero, - carbon oxide gas permeates only toward the inside of the container (7) from the fluid;
There is no carbon monoxide gas going in the opposite direction, i.e. into the vessel (into the force) and into the fluid, and no permeation occurs.

Therefore, the responsiveness of gas concentration detection is good regardless of whether the measurement is performed using the permeability of the membrane.

Furthermore, since the gas concentration is detected by measuring the concentration of gas that has passed through the membrane, the permeable membrane (8) will not be clogged even if the liquid contains a large amount of differentiated coal and a considerable amount of water. Furthermore, for the same reason, it is possible to continue accurate and stable measurements without clogging, even when the fluid flow velocity or pressure fluctuates greatly and a force that generates a fluid flow inside the container is applied. .

Note that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

The device for measuring the concentration of carbon monoxide gas in dregs containing coal dust according to the present invention has the above-described configuration, and therefore exhibits the following excellent effects.

(1) The concentration of carbon monoxide scum that has passed through the permeable membrane due to permeation is directly measured without filtering the fluid containing dust and moisture or installing a moisture removal device as in the past. No clogging of the membrane occurs. Therefore, the concentration of carbon monoxide residue in a fluid containing a large amount of dust and moisture can be measured accurately and stably.

(11) The measuring device is composed of a container in which the measuring device is placed, a measuring device, and a permeable membrane interposed between the measuring device and the fluid to be measured, so the structure is extremely simple and the measuring operation is easy. It's simple.

(iii) By connecting the measuring device of the present invention to an alarm cover, it is possible to prevent an explosion accident of -carbon oxide scum.

[Brief explanation of the drawing]

1 to 6 are explanatory diagrams showing an outline of a conventional carbon monoxide gas concentration measuring device, and FIG. 4 is a layout diagram showing the installation position of a carbon monoxide gas concentration measuring device according to an embodiment of the present invention. Figure 5 is a partially enlarged perspective view of the same <97g4 measuring device;
6 is a partially cutaway side view of FIG. 5, and FIG. 7 is a partially enlarged side view of FIG. 6. In the figure, (1) is the pulverized coal mill, (4) is the output rotary tank l-1 (
71 is a container, (8) is a permeable membrane, and (10) is a detection section. Patent applicant Ishikawajima Harima Heavy Industries Co., Ltd.

Claims (1)

[Claims] 1) Incorporating a measuring device ~ In a carbon monoxide gas concentration measuring device that receives carbon monoxide residue in a container and measures the gas concentration, a permeable membrane is provided at the part where carbon monoxide gas outside the container is introduced. A device for measuring carbon monoxide gas concentration in gas containing coal dust, characterized by: