JPS63214326A - Dilution device for solid-gas mixed phase fluid - Google Patents

Abstract

PURPOSE:To measure particle distribution and concentration with high accuracy by providing a measuring piping which has an opening facing to an inlet nozzle at one end and with its other end connected with a measuring instrument, and also an outlet with openings at the other end of a mixing chamber and an adjacent barrel. CONSTITUTION:Dilution gas blown off from a blow-off opening 12 is sufficiently mixed with solid-gas mixed phase fluid flowing in from an inlet nozzle 10 for the solid-gas mixed phase fluid 1, and an inlet nozzle 11 of dilution gas is installed at one end of a mixing chamber 9, while the dilution gas is introduced from the blow-off opening 12 constituted of micro-porous plates into the mixing chamber 9. The inner diameter of the mixing chamber 9 should be so designed as to make a turbulence generating no positional concentration distribution of solid particles, in consideration of mixing properties of solid-gas mixed phase fluid and diluted gas flowing in the mixing chamber. A piping 13 which feeds the solid-gas mixing phase fluid after being diluted to a measuring instrument should basically be positioned at the rear, and the dimension of the inner diameter and the like of the piping 13 should take agglomeration and deposition in the piping 13 into consideration.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides relatively fine particles after coarse particles are removed from solid-gas mixed-phase fluids in plants that handle solid-gas mixed-phase fluids such as boilers, incinerators, and cement manufacturing equipment. This invention relates to a solid-gas mixed phase fluid dilution device for measuring the concentration and particle size distribution of solid particles.

[Conventional technology]

In order to measure solid particles in a solid-gas mixed phase fluid as described above, it is necessary to accurately grasp the actual concentration and particle size distribution from the viewpoints of environmental preservation, research improvement, understanding of equipment performance, continuous status, monitoring, etc.

K, which aims to measure the concentration and particle size distribution with high accuracy, introduces the solid-gas multiphase fluid from the main stream of the solid-gas multiphase fluid to the measuring device without causing any change in the state of the solid particles (changes in the concentration or particle size distribution). It is necessary.

[Problem to be solved by the invention]

However, "Brownian diffusion" is an inherent characteristic of particles.
Condensation between particles and deposition on the inner wall of the introduction tube occur due to "collision" and "static electricity if the particles are electrically charged", and these phenomena significantly reduce measurement accuracy.

In particular, the above phenomenon generally tends to become more pronounced as the solid particle concentration increases and as the particles become more atomized. Particular measures are required when targeting fine particles called airborne particles.

Furthermore, as a general characteristic of measuring instruments that measure solid particles in a solid-gas mixed phase fluid, (:) measurement accuracy usually decreases significantly under high concentrations such as those mentioned above.

(1i) Measurable sampling gas temperature is often close to atmospheric temperature, and it is necessary to lower the sampling gas temperature.

(m) Moisture, sulfur dioxide (So,
) When a gas is contained, if the gas temperature is directly lowered, the solid particles to be measured will aggregate, causing a change in particle size distribution and concentration.

[Means to solve the problem]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides a diluting device for a solid-gas mixed-phase fluid, which makes it possible to measure the particle size distribution and concentration with high accuracy even when the solid particles to be measured are highly concentrated and fine particles. As an embodiment of the present invention, the present invention includes a tubular mixing chamber whose both ends and a body are surrounded by outer walls, and a solid-gas mixed phase opening at the center of one end of the mixing chamber. A diluent gas outlet comprising a fluid inlet nozzle and a plurality of pores or annular nozzle holes connected to a diluent gas supply pipe and arranged at one end so as to surround the inlet nozzle. A measuring pipe that penetrates the body near the other end of the chamber and is inserted into the center of the mixing chamber, has an opening facing the inlet nozzle at its tip, and has the other end connected to a measuring device. and an outlet opening into the body at or near the other end of the mixing chamber.

[Effect]

That is, in the dilution device according to the present invention, the solid-gas mixed-phase fluid collected for the purpose of measurement from the solid-gas mixed-phase fluid main stream is purified and dehumidified using an inert gas (hereinafter simply referred to as dilution gas) to dilute the solid-gas multiphase fluid as listed above. Since the solid particles are diluted in a dilution container having a predetermined residence time and capacity of the solid-gas multiphase fluid until the solid particle concentration, measurement temperature, and condensed component concentration are below a predetermined value without causing any problems, the solid particles are removed from the dilution container. Part or all of the diluted solid-gas multiphase fluid whose concentration, temperature, and condensed component concentration have been adjusted can be measured using a solid particle measuring device.

〔Example〕

First, the principle of dilution by the apparatus according to the present invention will be explained with reference to FIG.

1 is a main stream of the solid-gas multiphase fluid flowing in the duct; 2 is a pipe for introducing the solid-gas multiphase fluid 1 into a dilution container 3, which will be described next;
3 is a dilution container for diluting the solid-gas multiphase fluid l sent through piping 2 to a predetermined concentration with a diluent gas without causing changes in the particle size distribution and concentration of solid particles; 4 is a clean and dehumidified inert container; Piping 5 supplies the diluted gas to the dilution container 3; Piping 5 supplies the diluted solid-gas multiphase fluid in the dilution container 3 to a solid particle measuring device 6, which will be described next; A solid particle measuring device (hereinafter simply referred to as a measuring device) for measuring the particle size distribution and concentration of particles; 7 is a suction device for sucking solid-gas mixed phase fluid from the dilution container 3 through piping 2 and 5 to the measuring device 6; A pump 8 discharges the remaining solid-gas mixed-phase fluid after dilution, excluding the solid-gas mixed-phase fluid supplied to the measuring device 6 in the dilution container 3, to the outside of the system.

Alternatively, it is a pipe that supplies to processing equipment such as other solid particle measuring instruments.

A solid-gas mixed phase fluid main stream 1 is introduced via a pipe 2 into a dilution container 3 according to the present invention. This dilution container 3 is intended to prevent the above-mentioned problems related to the characteristics of the particles themselves and the characteristics of the measuring device.

An embodiment of the dilution container used in the present invention shown in FIGS. 2 and 3 will be described.

Reference numeral 9 denotes a mixing chamber of the dilution container 3, 10 an inlet nozzle for the solid-gas mixed phase fluid supplied by the pipe 2 in FIG. 1, 11 an inlet nozzle for the dilution gas supplied by the pipe 4 in FIG.
Reference numeral 2 indicates a dilution gas outlet for blowing out the dilution gas sent from the inlet nozzle 11 at a predetermined speed into the solid-gas multiphase fluid entering the mixing chamber 9 from the inlet nozzle 10; A pipe 14 for supplying solid particles to the measuring device is an outlet for the remaining solid-gas mixed-phase fluid after dilution, excluding the solid-gas mixed-phase fluid supplied to the measuring device in the dilution container.

The flow rate of the diluent gas blown out from the diluent gas Suita port 12 is set so as to satisfy the following conditions, taking into account problems related to the measuring device 6 and the inherent characteristics of the solid particles.

(1) Dilute the solid-gas mixed-phase fluid to a predetermined concentration of the measuring instrument 6 (which allows measurement with the highest accuracy) in order to prevent a decrease in the accuracy of the measuring instrument itself under a high-concentration solid-gas mixed-phase fluid. In other words, the dilution gas flow rate Q1 is determined using equation (1).

Qt〉Qs: n! - 0m However, Ql: Dilution gas flow rate (cd/wt) Qs: Sampling flow rate from the main stream of solid-gas mixed phase flow (cd/sec) (Flow rate of solid-gas mixed-phase fluid flowing in from the inlet nozzle 10) ns: Approximate solid-gas mixed phase flow Fluid concentration (numbers/, -j) nm: Upper limit of solid-gas multiphase fluid concentration of the measuring device (numbers/-) (2) Concentration and particle size due to condensation of condensed components accompanying cooling of solid-gas multiphase fluid to near atmospheric temperature In order to prevent changes in distribution and morphology, the concentration of condensed components is reduced by diluting until no condensation occurs even after cooling.

In other words, the dilution gas flow rate in the case of the above is also determined using equation (2).

s Q2≧QSCo.

However, Qz: Diluent gas flow rate (I!/lK11) Qs: Sampling flow rate from solid-gas multiphase fluid (//condition) C8: Concentration of condensed component in solid-gas multiphase fluid to be sampled (vol %) COO: Solid after cooling Temperature of gas multiphase fluid (ambient atmospheric temperature)
The saturation concentration (vol %) of the condensed component in Coo can be investigated in various literatures, but for example, in the case of water often contained in combustion exhaust gas.

It can be easily determined using a humidity chart.

(3) Coagulation between solid particles due to Brownian diffusion and collisions.

Dilute with diluent gas to prevent deposition.

Aggregation and deposition of particles can be determined as a theoretical solution using Fick's law. For example, agglomeration.

Changes in the number of numerals due to deposition can be calculated using equations (3) and (4).

1”-1 °. - One; "■-(3) However, no = particle number concentration in the initial state (t = o) (
particles/-) ni: particle number concentration after seconds (particles/-) k: constant (
t-j/piece/kick) t: Elapsed time (me) Anal-8-? n.

However, no: particle number concentration in the initial state (t=o) (
particles/c1d) nt: Particle number concentration (particles/-) after seconds? Two constants (
- Equations (3) and (4) show that the larger no, the smaller nt7ho, so nt/no does not affect measurement accuracy (generally 5% considering the accuracy of the measuring instrument and the overall measurement).
(less than). This means that it needs to be diluted.

Therefore, the dilution gas flow rate Qs is determined by equation (5).

Q->Qs Lid Q: Diluent gas flow rate (-/cap) QS: Sampling flow rate from solid-gas mixed phase fluid (crtl
/ sarins: approximate solid-gas mixed phase fluid concentration (numbers/-) ffo: f3
nt/no in formulas 1 and (4) is the concentration of solid-gas mixed phase fluid after dilution (pcs/-) to the extent that it does not affect measurement accuracy. Satisfies formulas (1), (2), and (5) above. Set the diluent gas flow rate as follows.

By the way, the approximate solid-gas mixed-phase fluid concentration l in equations (1) and (5) is the concentration and particle size distribution of intermediate to coarse particles in the main stream of the fluid containing the same solid-gas mixed-phase fluid, based on the official standards such as JIS. Based on the measured values of known measurement methods (for example, method 1 for measuring dust concentration in exhaust gas specified in JIS), and after removing intermediate to coarse particles using inertial methods such as cyclones, which are frequently used in the past. Only fine particles are collected on a P paper filter, and the concentration of the fine particles is determined in advance from the measured value of the measurement method, etc., which determines the concentration of the fine particles based on the weight of the particles attached to the filter.

On the other hand, regarding the structure of the dilution container 3, (1) the outlet 12 that blows out the dilution gas is used to sufficiently mix the solid-gas mixed-phase fluid 1 flowing in from the inlet nozzle 10; An inlet nozzle 10 is provided at the center of one end, and an inlet nozzle 11 for diluting gas is provided around it, and the diluting gas is introduced into the mixing chamber 9 through an outlet 12 made of a microporous plate.

Therefore, the flow rate of the diluent gas blown out from the outlet 12 is set at approximately 3 to 30 m/a, taking into account the mixing property, and the area, number of holes, etc. of the outlet 12 are designed to achieve this flow rate.

(2) The inner diameter of the mixing chamber 3 is designed in consideration of the miscibility of the solid-gas multiphase fluid flowing therein and the diluent gas, and is designed to create a turbulent flow state to the extent that no local concentration distribution of solid particles occurs.

(3) The length of the large mixing chamber 3 is the residence time of the solid-gas mixed phase fluid after dilution, which is approximately proportional to the elapsed time in equation (3), and is lengthened. As is clear from equation (3), if Vcnt/no becomes small, there is a possibility that the measurement accuracy will be affected, so design is performed taking equation (3) into consideration.

(4) Piping 1 that supplies diluted solid-gas multiphase fluid to the measuring instrument
3 is basically located at the rear, and the dimensions such as the inner diameter of the pipe 13 are (
Design with reference to equations 3) and (4).

(5) The discharge port 14 for the solid-gas mixed phase fluid after dilution should have a shape and dimensions that will not cause a large pressure loss in the same area.

In the dilution vessel 3 shown in FIGS. 2 and 3.

Although the structure is designed to satisfy the above five items, the structure is not limited to the embodiment, and structures such as those shown in FIGS. 4 and 5 may also be considered.

The reference numerals are given in the same manner as in FIG. 2, but the diluent gas outlet 12 is characteristically arranged in an annular manner around the inlet nozzle 10.

〔Effect of the invention〕

In other words, the present invention uses a clean and dehumidified diluent gas to measure a solid-gas multi-phase fluid sampled from the main flow of the solid-gas multi-phase fluid for the purpose of measurement at a predetermined solid particle concentration that does not affect measurement accuracy. This relates to a device that dilutes a solid-gas mixed phase fluid in a dilution container having a predetermined residence time and capacity until the temperature and concentration of condensed components are lowered, so the concentration of solid particles, temperature, and concentration of condensed components can be measured from the dilution container. Part or all of the adjusted solid-gas mixed phase fluid after dilution is useful in terms of experimental technology, such as making it possible to measure its particle size distribution and concentration with high precision using a solid particle measuring instrument.

Brief explanation of the previous aspects Figure 1 is a schematic explanatory diagram showing the principle of the present invention, Figure 2 is a longitudinal cross-sectional view showing an embodiment of the diluting device of the present invention, and Figure 3 is a cross-sectional view of ■-■ in Figure 2. 4 is a longitudinal sectional view showing different embodiments of the diluting device of the present invention, and FIG. 5 is a cross-sectional view taken along line v-■ in FIG.
FIG.

DESCRIPTION OF SYMBOLS 1... Solid-gas mixed phase fluid, 2... Piping, 3... Dilution container, 4.5... Piping, 6... Measuring instrument, 7... Suction pump.

8... Piping, 9... Mixing chamber, 10... Solid-gas mixed phase fluid inlet nozzle, 11... Dilution gas inlet nozzle, 1
2...Air outlet, 13...Piping, 14...Discharge port.

Standard flash Eel whale praise

Claims (1)

[Claims] a tubular mixing chamber having both ends and a body surrounded by outer walls; an inlet nozzle for a solid-gas mixed phase fluid that opens at the center of one end of the mixing chamber; and the inlet nozzle connected to a dilution gas supply pipe. a dilution gas outlet comprising a large number of pores or annular nozzle holes arranged at one end so as to surround the mixing chamber; is inserted to the center of the mixing chamber, has an opening facing the inlet nozzle at its tip, and connects the other end to a measuring pipe connected to a measuring instrument, and the other end of the mixing chamber or a nearby body. 1. A diluting device for a solid-gas mixed phase fluid, comprising: a discharge port that opens.