JPH0414158B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical field to which the present invention pertains] The present invention relates to a method and apparatus for adding odor to gas, and more specifically, to a method for odorizing gas and an apparatus for the same. This invention relates to a method and an apparatus for adding odor to supplied gas by a bypass method for safety reasons.

[Conventional technology]

FIG. 1 shows a conventional odorization device based on a bypass system, in which a bypass pipe 03 that bypasses a throttle mechanism 02 is attached to a gas conduit 01, and an odorant tank 04 is attached inside this bypass pipe 03.
The odorizing agent is evaporated and saturated in the gas passing through the bypass pipe 03.

[Problems with conventional technology]

Since the conventional bypass type odorization method (device) has the above-described configuration, it has a drawback that the odor concentration changes when there are fluctuations in the temperature and pressure of the gas passing through the bypass pipe. Therefore, in the past, bypass pipe 03
A manual valve 05 is installed inside the bypass pipe 03, and while operating the manual valve 05 relying on experience and intuition, the amount of gas passing through the bypass pipe 03 is adjusted so that the concentration falls within a specified range. There is.

However, with the above method, only an experienced person can make adjustments, and in equipment where temperature and pressure changes are large, the valves must be operated frequently, making it impossible to handle them realistically. Therefore, although the conventional method has many advantages over other odorizers, its adoption has been postponed.

[Object of the present invention]

In view of the above points, the present invention aims to propose an odor adding method in which the odor concentration does not change even if there are changes in pressure and temperature passing through the bypass pipe, and an odor adding device used in this method. .

[Configuration of the present invention]

In order to achieve the above object, the present invention detects the pressure and temperature of the gas passing through the bypass pipe (line), calculates the following equation based on the detected values, calculates the correction value, and calculates the correction value. The odor concentration is maintained constant while controlling the flow rate by automatically controlling the flow rate control valve installed in the bypass pipe based on the correction value.

First, in Fig. 2, the flow rate of gas passing through the gas conduit 1 is assumed to be V ₁ (Nm ³ /h), and the flow rate of gas passing through the bypass pipe 2 is assumed to be V ₂ (Nm ³ /h). Assuming that the fluid resistance other than the flow control valve in the bypass flow path can be almost ignored, ● Dividing ratio V ₁ /V ₂ = CV ₂ /CV ₁ ... (∵Pressure drop ΔP is common) CV ₁ ...Main gas Capacity coefficient of conduit nozzle CV ₂ ... Capacity coefficient of bypass pipe flow control valve● Odorant balance Evaporation amount F _T (g/h), dripping rate α (g/Nm ³ ), A
Volatilization amount γ at a point (g/Nm ³ ) F _T =α・(V ₁ +V ₂ )=V ₂・γ V ₂ /V ₁ +V ₂ ≒V ₂ /V ₁ = α/γ ... (∵V ₁ ≫V ₂ ) ● Relationship between gas pressure and volatilization amount at point A Gas pressure P ₁ (Kg/cm ² abs), Odorant saturated vapor pressure P _D
(mmH ₂ O), constant K determined by the type of odorant γ＝P _D /P ₁ −P _D ×10 ^-4 ×K ≒K・Pn／P ₁・P _D …… (∵P ₁ ≫P _D ) ● Saturated vapor pressure characteristics of odorant Gas temperature t (°C) P _D = (t ₁ ) ... From the formula, V ₂ /V ₁ = CV ₂ /CV ₁ = α / γ = α・P ₁ /K・(t ₁ )・Pn
... From the formula, CV ₂ α・CV ₁ /K・P ₁ /Pn・1/(t ₁ )...

From the above calculations, if the control value (CV) of the control valve 3 with linear characteristics attached to the bypass pipe 2 is characterized as a function of pressure and temperature as shown in the above equation, highly quantitative odor addition is possible. becomes.

In Fig. 2, 4 is a computing unit, 5 is a signal line connecting this computing unit 4 and the control valve 3, 6 is an odorizer, 7 is a pressure detection point, 8 is a temperature detector, 9, 10
is a signal line, and 11 is a temperature converter.

FIG. 3 shows the odorizing device indicated by the reference numeral 6,
A pipe 12 is inserted vertically into the odorant tank 6, and gas 13 is introduced from the gas conduit 1 into a part of the pipe 12 and fed into the pipe 12, and the odorant tank 6 is filled using a bubble pump method. The odorant inside the tank is guided to the upper part of the tank and evaporated into the gas that enters the tank from the bypass pipe 2 to saturate it.

FIG. 4 shows another embodiment of the odorizer, in which a meandering channel 15 is formed by inserting the partition plate 14 into the odorant tank 6 while shifting it in the vertical direction. The structure is such that the odorant is evaporated and saturated in the gas that enters the tank from the bypass pipe 2. In addition, if porous materials such as fibers that are highly compatible with the odorizing liquid are attached to both sides of the partition plate 14, the contact area between the gas and the odorizing liquid can be expanded, and the saturated state can be maintained up to a high flow rate range. The scope of application of this device can be expanded.

FIG. 5 shows another embodiment of the odorizer, in which a gas feed pipe 16 is inserted from above into the center of the canopy of the odorizer tank 6, and a float 17 in the tank is used to position it slightly away from the liquid level. The gas inlet 19 of the umbrella-shaped ejection body 18 floated in the air is inserted into the gas supply pipe 16 so as to be able to move up and down, and the odorant is stably evaporated and saturated while constantly following fluctuations in the liquid level. It is. Numeral 20 is a multi-legged skirt formed around the umbrella-shaped ejector 18 to promote contact between the gas and the odorized liquid.

[Effects of the present invention]

As described above, the present invention detects when there is a change in gas pressure or when a temperature change occurs in the gas, resulting in a change in saturated vapor pressure, and calculates a correction value from this detected value. By doing so, the amount of gas passing through the bypass pipe 2 is controlled and the odor concentration is stabilized, so troubles due to changes in the odor concentration can be prevented from occurring.

Next, by adopting the bubble pump method as shown in Fig. 3, the meandering flow path method as shown in Fig. 4, and the float method as shown in Fig. 5 as the odorization device, it is possible to reach a high flow rate range. The saturated state of the odorizing liquid is guaranteed.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a conventional bypass type odorizer.
Fig. 2 is an embodiment of the odorization method and device according to the present invention, Fig. 3 A and B are cross-sectional views of an odorization device employing a bubble pump system, and Fig. 4 A and B are serpentine flow diagrams. FIGS. 5A, 5B, and 5C are cross-sectional views of an odorizer that uses a float method. DESCRIPTION OF SYMBOLS 1... Gas conduit, 2... Bypass pipe, 3... Flow rate control valve, 4... Arithmetic unit, 6... Odorization device.

Claims (1)

[Claims] 1. A bypass pipe is attached to the gas conduit, and an odorant tank is attached to a part of the bypass pipe, and an odorant is evaporated into the gas passing through the bypass pipe to saturate the gas. In the odor method, the pressure in the odorant tank and the temperature on the outlet side or near the outlet of the tank are detected, and a correction value is calculated from these two fluctuation values to adjust the flow rate of gas passing through the bypass pipe. How to add odor to. 2 A pipe is inserted vertically into the odorant tank, and a part of the gas in the gas pipe is fed into this pipe, and the odorant is guided to the upper part of the tank, where it is diffused and evaporated. odor-adding device. 3 A meandering flow path is formed by shifting the partition plate in the vertical direction of the odorant tank and evaporating the odorant by passing the gas in the bypass pipe through this meandering flow path. An odor-adding device configured as follows. 4. Attach a gas supply pipe from above to the center of the canopy of the odorant tank, insert the gas inlet of the umbrella-shaped ejector with a float attached to the lower part into the gas supply pipe so that it can move up and down, and then An odorant device configured to evaporate the odorant by bringing the spout close to the liquid surface.