CN203551337U - Dynamic pressure balance type constant-speed soot sampling tube - Google Patents

Abstract

The utility model discloses a dynamic pressure balance type constant-speed soot sampling tube which comprises a sampling tube body, wherein the sampling tube body comprises a sampling nozzle, a bent tube, a filter drum casing, a pore plate connecting tube, a main casing and a pitot tube; a pore plate, a main air guide tube, a front pressure measuring tube and a rear pressure measuring tube are arranged in the main casing; both sides of the pore plate are provided with a front air chamber and a rear air chamber; the pitot tube passes through the main casing and is welded integrally with the main casing. Adaptability to constant-speed soot sampling at different flow speeds is realized by replacing a plurality of sampling nozzles with a plurality of diameters, so that the accuracy and the efficiency of constant-speed soot sampling are improved greatly. The pitot tube and the sampling tube body are integrated, so that an operator can hold conveniently, the sealing is facilitated, toxic and harmful gas in a flue is prevented from leaking out, and the accuracy of monitoring data is improved.

Description

Dynamic pressure balancing constant speed soot sampling tube

Technical field

The utility model belongs to environment monitoring apparatus field, relates to soot sampling tube, is specifically related to a kind of dynamic pressure balancing constant speed soot sampling tube.

Background technology

In the industries such as environmental protection, metallurgy, building materials, chemical industry, electric power, in order to carry out environmental evaluation, equipment Design & reform, operating mode technical Analysis, usually need the fume emission behaviour of stationary pollution source industry coal-boiler chimney to monitor, measure the thermal parameter of air flue soot dust concentration, smoke discharge amount, smoke discharge amount and associated conduit.In Technology of Smoke-dust, there is the instrument of three kinds of smoke dust sampling methods: 1. predicted velocity method; 2. Parallel Sampling method; 3. constant speed pipe method, divides again dynamic pressure balancing and static pressure balanced in constant speed pipe method kind, because the static-pressure inlet of static pressure balanced sampling pipe is easily stopped up by flue dust, now not too uses, and conventionally uses dynamic pressure balanced soot sampler with the instrument of constant speed pipe method.

In smoke dust sampling process, in order to collect representational smoke sample from flue, require isokinetic sampling, gas enter sampling mouth flow velocity should equate with the flue gas flow rate of sampled point.Three kinds of smoke dust sampling methods, respectively have its feature, and early stage, manually instrument, when operating mode shakiness, change large, frequency when high, was difficult to realize constant speed tracking sampling.Constant speed pipe method dynamic pressure balanced soot sampler device, to manage sampling with special dynamic pressure balancing isokinetic sampling, the sampled point gas dynamic pressure of the differential pressure of the orifice plate of use device on sampling pipe and pitot tube indication balances each other to realize isokinetic sampling, this method does not need to measure in advance temperature, pressure, flow velocity and the humidity of flue gas of measuring point just can sample, constant speed response is fast, adapt to dust concentration scope wide, welcome by user.Along with electronic technology, technical development of computer, dynamic pressure balanced soot sampler has also just carried out semi-automatic, full-automatic upgrading, the method smoke dust sampler has had large increase in performance, but the method instrument has a maximum weakness, it is exactly a kind of corresponding orifice plate of sampling mouth of diameter, to be equipped with the flue dust test that many sampling pipes could adapt to different flue gas flow rates, conventionally join Φ 6mm, the sampling pipe of the perforated plate of Φ 8mm sampling mouth, this makes troubles to flue dust test job person, flue dust test site condition is conventionally poor, also need to be with many sampling pipes, different different sampling pipes for flow velocity section, increased flue dust test job person's labour intensity.

Summary of the invention

The purpose of this utility model is for above-mentioned defect, and a kind of dynamic pressure balancing constant speed soot sampling tube with constant aperture orifice plate is provided, thereby completes the constant speed smoke dust sampling of different in flow rate.

Above-mentioned purpose is achieved through the following technical solutions:

A kind of dynamic pressure balancing constant speed soot sampling tube, comprise sampling pipe body, described sampling pipe body comprises sampling mouth, bend pipe, filter cylinder sleeve pipe, orifice plate adapting pipe and main sleeve pipe, described sampling mouth is located at the top of bend pipe, in described filter cylinder sleeve pipe, be provided with filter cylinder holder, the inlet end of described filter cylinder holder is provided with filtering cartridge lid, described filtering cartridge lid is fixed on filter cylinder sleeve pipe by compressing spiral cover, described filtering cartridge lid is provided with through hole, the other end of described bend pipe is communicated with filter cylinder holder through through hole, the outlet side of described filter cylinder sleeve pipe is communicated with orifice plate adapting pipe, in described main sleeve pipe, be provided with orifice plate, main gas tube, front piezometric tube and rear piezometric tube, the both sides of described orifice plate are respectively equipped with front air chamber and rear gas chamber, described orifice plate adapting pipe, front air chamber, rear gas chamber, main gas tube is communicated with successively, described front air chamber is communicated with front piezometric tube, described rear gas chamber is communicated with rear piezometric tube, also comprise pitot tube, described pitot tube is through main sleeve pipe.

Described pitot tube and main sleeve pipe are integrally welded.

Described sampling mouth is threaded with bend pipe.

The inner side of described compression spiral cover is connected with the outside screw of filter cylinder sleeve pipe.

The utility model, by freely changing the sampling mouth of multiple diameter, adapts to the constant speed smoke dust sampling of different in flow rate, thereby has greatly improved flue dust isokinetic sampling accuracy and efficiency.And original dynamic pressure balancing constant speed soot sampling tube can only correspondingly be used a sampling mouth, conventionally need the sampling of many cover sampling pipes, be difficult to adapt to the isokinetic sampling of wide flow rates, when gathering the smoke sample of different in flow rate, replace tubes needs connecting pipeline again, troublesome poeration, and the utility model is by installing pitot tube additional, thereby only need change front-end sampling mouth and can realize the smoke dust sampling of different in flow rate, greatly simplify pipeline join operation.The utility model resides in one by pitot tube and sampling pipe body, weight saving on the whole, and operator grips conveniently, but also is conducive to sealing, prevents overflowing of flue toxic and harmful, improves the accuracy of Monitoring Data.

Accompanying drawing explanation

Fig. 1 is structural representation of the present utility model;

Fig. 2 is the B-B sectional view of Fig. 1;

Fig. 3 is the local enlarged diagram of the utility model aperture plate and assembly thereof;

Fig. 4 is the A-A sectional view of Fig. 1;

Fig. 5 is use view of the present utility model.

In figure: 1-sampling pipe body, the 2-mouth of sampling, 3-bend pipe, 4-filter cylinder sleeve pipe, the adapting pipe of 5-orifice plate, the main sleeve pipe of 6-, the holder of 7-filter cylinder, 8-filtering cartridge lid, 9-compresses spiral cover, 10-orifice plate, 11-main gas tube, piezometric tube before 12-, piezometric tube after 13-, air chamber before 14-, 15-rear gas chamber, 16-pitot tube, 17-temperature sensor.

Embodiment

Below in conjunction with accompanying drawing and embodiment, the utility model is elaborated.

Embodiment: as Figure 1-4, a kind of dynamic pressure balancing constant speed soot sampling tube, comprise sampling pipe body 1, described sampling pipe body 1 comprises sampling mouth 2, bend pipe 3, filter cylinder sleeve pipe 4, orifice plate adapting pipe 5 and main sleeve pipe 6, described sampling mouth 2 is located at the top of bend pipe 3 and is threaded with bend pipe 3, in described filter cylinder sleeve pipe 4, be provided with filter cylinder holder 7, the inlet end of described filter cylinder holder 7 is provided with filtering cartridge lid 8, described filtering cartridge lid 8 is fixed on filter cylinder sleeve pipe 4 by compressing spiral cover 9, and the inner side of described compression spiral cover 9 is connected with the outside screw of filter cylinder sleeve pipe 4.Described filtering cartridge lid 8 is provided with through hole, the other end of described bend pipe 3 is communicated with filter cylinder holder 7 through through hole, the outlet side of described filter cylinder sleeve pipe 4 is communicated with orifice plate adapting pipe 5, in described main sleeve pipe 6, be provided with orifice plate 10, main gas tube 11, front piezometric tube 12 and rear piezometric tube 13, the both sides of described orifice plate 10 are respectively equipped with front air chamber 14 and rear gas chamber 15, described orifice plate adapting pipe 5, front air chamber 14, rear gas chamber 15, main gas tube 11 is communicated with successively, described front air chamber 14 is communicated with front piezometric tube 12, described rear gas chamber 15 is communicated with rear piezometric tube 13, also comprise pitot tube 16, described pitot tube 16 is through main sleeve pipe 6 and integrally welded with main sleeve pipe 6.

While implementing sampling, glass fiber filter cylinder is put into filter cylinder holder 7, the conical surface of filtering cartridge lid 8 is inserted in filter cylinder and compressed, screw and compress spiral cover 9, can guarantee to seal not bypass gas leakage.

Within the scope of the flue gas flow rate of setting, adopt the orifice plate 10 that diameter is D, loading onto diameter is d _dsampling mouth 2, mix dynamic pressure balanced soot sampler and just can directly carry out flue dust isokinetic sampling.If flue gas flow rate is not d at diameter _dthe usable range of sampling mouth 2 in, realize flue dust isokinetic sampling, the diameter that just needs to change sampling mouth 2 is d, makes sampling flow in the efficient working range of the aspiration pump of instrument, flow sensor, this just need to revise orifice plate differential pressure P _nwith flue gas dynamic pressure P _dscale-up factor k, realize P _n=kP _d.

In different flow velocity sections, the orifice plate sampling pipe that is D with diameter, the outspoken footpath of change sampling completes the constant speed smoke dust sampling of different in flow rate, need to determine different in flow rate section, selects the sampling mouth 2 of different-diameter d, establishes different orifice plate differential pressure P simultaneously _nwith flue gas dynamic pressure P _dscale-up factor k value, through theory, calculate:

$k=\frac{d^4}{{{\mathrm{<figure-callout\; id="4"\; label="d\; D"\; filenames="HDA0000392747130000011.png,HDA0000392747130000021.png"\; state="\{\{state\}\}">d</figure-callout>}}_D}^4}$

K ... orifice plate differential pressure P _nwith flue gas dynamic pressure P _dscale-up factor

D _ddiameter is sampling mouth 2 diameters of orifice plate 10 correspondences of D

D ... sampling mouth 2 diameters during sampling

Sampling pipe constant speed principle:

The gas dynamic pressure that utilizes the differential pressure of sampling pipe up-hole plate 10 and the pitot tube of parallel placement 16 to indicate balances each other to realize isokinetic sampling, and its principle can represent by following relationship.When with pitot tube 16 mensurated gas composition flow velocity, the relational expression of flow velocity and dynamic pressure is as follows:

$v_s=K\sqrt{\frac{2P_d}{{\mathrm{\&rho;}}_s}}$ …………①

In formula:

V _s------gas flow rate, m/s;

K------pitot tube correction coefficient;

P _d------gas dynamic pressure; Pa;

ρ _s------gas density, kg/m ³.

While measuring sampling flow velocity with orifice plate 10, the relational expression of orifice plate 10 front and back differential pressures and flow velocity is as follows:

$v_n=\mathrm{\&alpha;\&epsiv;}\sqrt{\frac{{2P}_n}{{\mathrm{\&rho;}}_n}}$ …………②

In formula:

V _n------sample rate, m/s;

α------coefficient of flow;

ε------expansion coefficient;

P _n------orifice plate differential pressure; Pa;

ρ _n------gas density, kg/m ³.

Because by sampling, mouth 2 enters the gas of orifice plate 10 and the gas of sample point is same gas, as little in filter cylinder resistance, can think that their density is consistent, and ρ _s=ρ _n, establish

above-mentioned two formulas can be write as following form:

$v_s=C\&CenterDot;K\sqrt{P_d}$ …………③

$v_n=\mathrm{\&alpha;}\&CenterDot;\mathrm{\&epsiv;}\&CenterDot;C\&CenterDot;\sqrt{P_n}$ …………④

If while making orifice plate 10, make orifice constant α ε=K, as orifice plate differential pressure P _nequal sample point gas dynamic pressure P _dtime, sampling flow velocity v _njust equal the gas flow rate v of sample point _s, realized isokinetic sampling v _n=v _s.

The system of dynamic pressure balancing constant speed smoke dust sampler forms as shown in Figure 5.

Start, to each pressure transducer automatic zero adjustment, for automatic result of calculation after sampling, arranges and measures correlation parameter; According to measuring dynamic pressure size, determine the diameter of sampling mouth 2, be beneficial in suitable sampling flow scope, adjust orifice plate 10 front and back differential pressures, from the dynamic pressure of motion tracking flue gas, complete isokinetic sampling.

Claims (4)

1. a dynamic pressure balancing constant speed soot sampling tube, comprise sampling pipe body (1), it is characterized in that: described sampling pipe body (1) comprises sampling mouth (2), bend pipe (3), filter cylinder sleeve pipe (4), orifice plate adapting pipe (5) and main sleeve pipe (6), described sampling mouth (2) is located at the top of bend pipe (3), in described filter cylinder sleeve pipe (4), be provided with filter cylinder holder (7), the inlet end of described filter cylinder holder (7) is provided with filtering cartridge lid (8), described filtering cartridge lid (8) is fixed on filter cylinder sleeve pipe (4) by compressing spiral cover (9), described filtering cartridge lid (8) is provided with through hole, the other end of described bend pipe (3) is communicated with filter cylinder holder (7) through through hole, the outlet side of described filter cylinder sleeve pipe (4) is communicated with orifice plate adapting pipe (5), in described main sleeve pipe (6), be provided with orifice plate (10), main gas tube (11), front piezometric tube (12) and rear piezometric tube (13), the both sides of described orifice plate (10) are respectively equipped with front air chamber (14) and rear gas chamber (15), described orifice plate adapting pipe (5), front air chamber (14), rear gas chamber (15), main gas tube (11) is communicated with successively, described front air chamber (14) is communicated with front piezometric tube (12), described rear gas chamber (15) is communicated with rear piezometric tube (13), also comprise pitot tube (16), described pitot tube (16) is through main sleeve pipe (6).

2. dynamic pressure balancing constant speed soot sampling tube according to claim 1, is characterized in that: described pitot tube (16) is integrally welded with main sleeve pipe (6).

3. dynamic pressure balancing constant speed soot sampling tube according to claim 1, is characterized in that: described sampling mouth (2) is threaded with bend pipe (3).

4. dynamic pressure balancing constant speed soot sampling tube according to claim 1, is characterized in that: the inner side of described compression spiral cover (9) is connected with the outside screw of filter cylinder sleeve pipe (4).

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