Introduction

Local exhaust ventilation plays the most active role in the complex of engineering means for normalizing sanitary and hygienic working conditions in production premises. At enterprises associated with the processing of bulk materials, this role is played by aspiration systems (AS), ensuring the localization of dust in places of its formation. Until now, general ventilation has played an auxiliary role - it provided compensation for the air removed by the AS. Research by the Department of MOPE BelGTASM has shown that general ventilation is integral part a complex of dust removal systems (aspiration, systems to combat secondary dust formation - hydraulic flushing or dry vacuum dust collection, general ventilation).

Despite the long history of development, aspiration has received a fundamental scientific and technical basis only in recent decades. This was facilitated by the development of fan manufacturing and the improvement of air purification techniques from dust. The need for aspiration from the rapidly developing metallurgical industries also grew. construction industry. A number of scientific schools have emerged aimed at solving emerging environmental problems. In the field of aspiration, the Ural (Butikov S.E., Gervasyev A.M., Glushkov L.A., Kamyshenko M.T., Olifer V.D., etc.), Krivoy Rog (Afanasyev I.I., Boshnyakov E.N., etc.) became famous , Neykov O.D., Logachev I.N., Minko V.A., Serenko A.V. and American (Khemeon V., Pring R.) modern basics design and methods for calculating the localization of dust emissions using aspiration. Developed based on them technical solutions in the field of design of aspiration systems are enshrined in a number of regulatory and scientific and methodological materials.

Real teaching materials summarize the accumulated knowledge in the field of designing aspiration systems and centralized vacuum dust collection systems (CVA). The use of the latter is expanding especially in production, where hydraulic flushing is unacceptable for technological and construction reasons. The methodological materials intended for the training of environmental engineers complement the course “Industrial Ventilation” and provide for the development of practical skills among senior students of the specialty 05/17/09. These materials are aimed at ensuring that students are able to:

Determine the required performance of local suction pumps and CPU nozzles;

Choose rational and reliable systems pipelines with minimal losses energy;

Define required power aspiration unit and select the appropriate draft means

And they knew:

Physical basis calculating the performance of local suction stations;

Fundamental difference hydraulic calculation CPU systems and AC air duct networks;

Structural design of shelters for reloading units and CPU nozzles;

Principles for ensuring the reliability of AS and CPU operation;

Principles for selecting a fan and features of its operation on specific system pipelines.

Guidelines are focused on solving two practical problems: “Calculation and selection of aspiration equipment (practical task No. 1), “Calculation and selection of equipment vacuum system cleaning up dust and spills (practical task No. 2).”

The testing of these tasks was carried out in the autumn semester of 1994 in practical classes of groups AG-41 and AG-42, to whose students the compilers express gratitude for the inaccuracies and technical errors they identified. Careful study of materials by students Titov V.A., Seroshtan G.N., Eremina G.V. gave us grounds to make changes to the content and edition of the guidelines.

1. Calculation and selection of aspiration equipment

Purpose of the work: to determine the required performance of the aspiration unit servicing the system of aspiration shelters for loading areas of belt conveyors, selecting an air duct system, a dust collector and a fan.

The task includes:

A. Calculation of the productivity of local suction (aspiration volumes).

B. Calculation of the dispersed composition and concentration of dust in the aspirated air.

B. Selecting a dust collector.

D. Hydraulic calculation of the aspiration system.

D. Selection of a fan and an electric motor for it.

Initial data

(The numerical values ​​of the initial values ​​are determined by the number of option N. The values ​​​​for option N = 25 are indicated in parentheses).

1. Consumption of transported material

G m =143.5 – 4.3N, (G m =36 kg/s)

2. Particle density of bulk material

2700 + 40N, (=3700 kg/m 3).

3. Initial moisture content of the material

4.5 – 0.1 N, (%)

4. Geometric parameters of the transfer chute, (Figure 1):

h 1 =0.5+0.02N, ()

h 3 =1–0.02N,

5. Types of shelters for the loading area of ​​the conveyor belt:

0 – shelters with single walls (for even N),

D – shelters with double walls (for odd N),

Conveyor belt width B, mm;

1200 (for N=1…5); 1000 (for N= 6…10); 800 (for N= 11…15),

650 (for N = 16…20); 500 (for N= 21…26).

Sf – cross-sectional area of ​​the gutter.

Rice. 1. Aspiration of the transfer unit: 1 – upper conveyor; 2 – upper cover; 3 – transfer chute; 4 – lower shelter; 5 – aspiration funnel; 6 – side outer walls; 7 – side internal walls; 8 – rigid internal partition; 9 – conveyor belt; 10 – end outer walls; 11 – end inner wall; 12 – lower conveyor

Table 1. Geometric dimensions of the lower shelter, m

Conveyor belt width B, m

Table 2. Particle size distribution of the transported material

Faction number j,
Size of openings of adjacent sieves, mm
Average fraction diameter d j, mm

* z =100(1 – 0.15).

Table 3. Length of sections of the aspiration network

Length of aspiration network sections
	for odd N		for even N

Rice. 2. Axonometric diagrams of the aspiration system of transfer units: 1 – transfer unit; 2 – aspiration pipes (local suction); 3 – dust collector (cyclone); 4 – fan

2. Calculation of the productivity of local suction

The basis for calculating the required volume of air removed from the shelter is the air balance equation:

The air flow rate entering the shelter through the leaks (Q n; m 3 / s) depends on the area of ​​the leaks (F n, m 2) and the optimal vacuum value in the shelter (P y, Pa):

(2)

where is the density of the surrounding air (at t 0 =20 °C; =1.213 kg/m3).

To cover the loading area of ​​the conveyor, leaks are concentrated in the area of ​​contact of the outer walls with the moving conveyor belt (see Fig. 1):

where: P – perimeter of the shelter in plan, m; L 0 – shelter length, m; b – shelter width, m; – height of the conventional gap in the contact zone, m.

Table 4. The magnitude of the vacuum in the shelter (P y) and the width of the gap ()

Type of transported material	Median diameter, mm	Shelter type "0"		Shelter type "D"
Lumpy
Grainy
Powdery

Air flow entering the shelter through the chute, m 3 /s

(4)

where S is the cross-sectional area of ​​the gutter, m2; – the flow rate of the reloaded material at the exit from the chute (the final speed of falling particles) is determined sequentially by calculation:

a) speed at the beginning of the chute, m/s (at the end of the first section, see Fig. 1)

, G=9.81 m/s 2 (5)

b) speed at the end of the second section, m/s

(6)

c) speed at the end of the third section, m/s

– coefficient of sliding of components (“ejection coefficient”) u – air speed in the chute, m/s.

The slip coefficient of components depends on the Butakov–Neikov number*

(8)

and Euler's criterion

(9)

where d is the average particle diameter of the material being handled, mm,

(10)

(if it turns out that , should be taken as the calculated average diameter; - the sum of the local resistance coefficients (k.m.c.) of the gutter and shelters

(11)

ζ in – k.m.s, air entry into the upper shelter, related to the dynamic air pressure at the end of the chute.

; (12)

F in – area of ​​leaks in the upper cover, m 2 ;

* Butakov–Neykov and Euler numbers are the essence of the parameters M and N widely used in regulatory and educational materials.

– Ph.D. gutters (=1.5 for vertical gutters, = 90°; =2.5 if there is an inclined section, i.e. 90°); –k.m.s. rigid partition (for shelter type “D”; in shelter type “0” there is no rigid partition, in this case lane = 0);

Table 5. Values ​​for type “D” shelter

Ψ – particle drag coefficient

(13)

β – volumetric concentration of particles in the gutter, m 3 / m 3

(14)

– the ratio of the particle flow velocity at the beginning of the chute to the final flow velocity.

With the found numbers B u and E u, the slip coefficient of the components is determined for a uniformly accelerated particle flow according to the formula:

(15)

The solution to equation (15)* can be found by the method of successive approximations, assuming as a first approximation

(16)

If it turns out that φ 1

, (17)

(18)

(20)

Let's look at the calculation procedure using an example.

1. Based on the given particle size distribution, we construct an integral graph of particle size distribution (using the previously found integral sum m i) and find the median diameter (Fig. 3) d m = 3.4 mm > 3 mm, i.e. we have the case of overloading lumpy material and, therefore, =0.03 m; P y =7 Pa (Table 4). In accordance with formula (10), the average particle diameter .

2. Using formula (3), we determine the area of ​​​​the leaks of the lower shelter (bearing in mind that L 0 = 1.5 m; b = 0.6 m, at B = 0.5 m (see Table 1)

F n =2 (1.5 + 0.6) 0.03 = 0.126 m 2

3. Using formula (2), we determine the flow of air entering through the leaks of the shelter

There are other formulas for determining the coefficient, including: for a flow of small particles, the speed of which is affected by air resistance.

Rice. 3. Integral graph of particle size distribution

4. Using formulas (5)… (7) we find the particle flow rates in the chute:

hence

n = 4.43 / 5.87 = 0.754.

5. Using formula (11), we determine the amount of k.m.s. gutters taking into account the resistance of shelters. When F in =0.2 m 2, according to formula (12) we have

With h/H = 0.12/0.4 = 0.3,

according to table 5 we find ζ n ep =6.5;

6. Using formula (14) we find the volumetric concentration of particles in the gutter

7. Using formula (13), we determine the drag coefficient
particles in the chute

8. Using formulas (8) and (9), we find the Butakov–Neikov number and the Euler number, respectively:

9. We determine the “ejection” coefficient in accordance with formula (16):

And, therefore, you can use formula (17) taking into account (18)… (20):

10. Using formula (4), we determine the air flow entering the lower shelter of the first transfer unit:

In order to reduce calculations, let us set the flow rate for the second, third and fourth reloading nodes

K 2 =0.9; k 3 =0.8; to 4 =0.7

We enter the calculation results in the first row of the table. 7, assuming that all reloading nodes are equipped with the same shelter, the air flow rate entering through the leaks of the i -th reloading node is Q n i = Q n = 0.278 m 3 /s. We enter the result in the second row of the table. 7, and the amount of expenses Q f i + Q n i – in the third. The amount of expenses , - represents the total productivity of the aspiration installation (air flow entering the dust collector - Q n) and is entered in the eighth column of this line.

Calculation of dispersed composition and dust concentration in aspirated air

Dust Density

The flow rate of air entering the exit through the chute is Q liquid (through leaks for the “O” type shelter – Q Нi = Q H), removed from the shelter – Q ai (see Table 7).

Geometric parameters of the shelter (see Fig. 1), m:

length – L 0 ; width – b; height – N.

Cross-sectional area, m:

a) aspiration pipe F in = bc.;

b) shelters between the outer walls (for departure type “O”)

c) shelters between the inner walls (for “D” type shelters)

where b is the distance between the outer walls, m; b 1 – distance between the internal walls, m; H – shelter height, m; с – length of the inlet section of the aspiration pipe, m.

In our case, with B = 500 mm, for a shelter with double walls (shelter type “D”) b = 0.6 m; b 1 =0.4 m; C =0.25 m; H =0.4 m;

F inx =0.25 0.6 =0.15 m2; F 1 =0.4 0.4 =0.16 m2.

Removing the aspiration funnel from the gutter: a) for shelter type “0” L y = L; b) for “D” type shelter L y = L –0.2. In our case, L y =0.6 – 0.2 =0.4 m.

Average air speed inside the shelter, m/s:

a) for type “D” shelter

b) for shelter type “0”

=(Q f +0.5Q H)/F 2 . (22)

Air entry speed into the aspiration funnel, m/s:

Q a /F in (23)

Diameter of the largest particle in the aspirated air, microns:

(24)

Using formula (21) or formula (22), we determine the air speed in the shelter and enter the result in line 4 of the table. 7.

Using formula (23), we determine the speed of air entry into the aspiration funnel and enter the result in line 5 of the table. 7.

Using formula (24), we determine and enter the result in line 6 of the table. 7.

Table 6. Mass content of dust particles depending on

Fraction number j	Fraction size, microns	Mass fraction of particles j-th faction(, %) at , µm

The values ​​corresponding to the calculated value (or the nearest value) are written out from column 6 of table and the results (in shares) are entered in rows 11...16 of columns 4...7 of table. 7. You can also use linear interpolation of the table values, but you should keep in mind that the result will be obtained, as a rule, and therefore you need to adjust the maximum value (to ensure ).

Determination of dust concentration

Material consumption – , kg/s (36),

Density of material particles – , kg/m 3 (3700).

Initial moisture content of the material –, % (2).

Percentage in the reloaded material there are finer particles – , % (at =149…137 microns, =2 + 1.5=3.5%. Consumption of dust reloaded with the material – , g/s (103.536=1260).

Aspiration volumes – , m 3 /s ( ). Entry speed into the aspiration funnel – , m/s ( ).

Maximum concentration of dust in the air removed by local suction from the i-th shelter (, g/m 3),

, (25)

Actual dust concentration in the aspirated air

where is the correction factor determined by the formula

in which

for shelters of type “D”, for shelters of type “O”; in our case (at kg/m3)

Or with W=W 0 =2%

1. In accordance with formula (25), we calculate .and enter the results in the 7th line of the summary table. 7 (we divide the specified dust consumption by the corresponding numerical value of line 3, and enter the results in line 7; for convenience, we enter the value in a note, i.e. in column 8).

2. In accordance with formulas (27...29), at the established humidity, we construct a calculated relationship of type (30) to determine the correction factor, the values ​​of which are entered in line 8 of the summary table. 7.

Example. Using formula (27), we find the correction factor psi and m/s:

If the dust content of the air turns out to be significant (> 6 g/m3), it is necessary to provide engineering methods to reduce the dust concentration, for example: hydro-irrigation of the material being reloaded, reducing the speed of air entry into the aspiration funnel, installing settling elements in the shelter or using local suction separators. If by means of hydroirrigation it is possible to increase the humidity to 6%, then we will have:

(31)

At =3.007, , =2.931 g/m 3 and we use relation (31) as the calculated ratio for.

3. Using formula (26), we determine the actual concentration of dust in the first local suction and enter the result in line 9 of the table. 7 (the values ​​of line 7 are multiplied by the corresponding i-th suction - the values ​​of line 8).

Determination of the concentration and dispersed composition of dust in front of the dust collector

For selection dust collection unit aspiration system serving all local suction, it is necessary to find the average parameters of the air in front of the dust collector. To determine them, the obvious balance relations of the laws of conservation of the mass transported through the air ducts of dust are used (assuming that the deposition of dust on the walls of the air ducts is negligible):

For the concentration of dust in the air entering the dust collector, we have an obvious relationship:

Keeping in mind that the expense dust j-i fractions in the i –th local suction

It's obvious that

(36)

1. Multiplying in accordance with formula (32) the values ​​of line 9 and line 3 of the table. 7, we find the dust consumption in the i –th suction, and enter its values ​​in line 10. We enter the sum of these expenses in column 8.

Rice. 4. Distribution of dust particles by size before entering the dust collector

Table 7. Results of calculations of the volumes of aspirated air, dispersed composition and dust concentration in local suction and in front of the dust collector

	Legend	Dimension	For the i-th suction				Note
							G/s at W=6%

2. Multiplying the values ​​of line 10 by the corresponding values ​​of lines 11...16, we obtain, in accordance with formula (34), the amount of dust consumption of the j-th fraction in i-th local suction. The values ​​of these quantities are entered on lines 17...22. The row-by-line sum of these values, entered in column 8, represents the consumption of the j-th fraction in front of the dust collector, and the ratio of these sums to total consumption dust in accordance with formula (35) is the mass fraction of the j-th fraction of dust entering the dust collector. The values ​​are entered in column 8 of the table. 7.

3. Based on the distribution of dust particles by size calculated as a result of constructing an integral graph (Fig. 4), we find the size of dust particles, smaller than which the original dust contains 15.9% of total mass particles (µm), median diameter (µm) and dispersion of particle size distribution: .

Most widespread when cleaning aspiration emissions from dust, inertial dry dust collectors were obtained - cyclones of the TsN type; inertial wet dust collectors - cyclones - SIOT workers, coagulation wet dust collectors KMP and KTSMP, rotoclones; contact filters – bag and granular.

For handling unheated dry bulk materials, NIOGAZ cyclones are usually used with dust concentrations up to 3 g/m 3 and microns or bag filters at high dust concentrations and smaller dust sizes. At enterprises with closed water supply cycles, inertial wet dust collectors are used.

Purified air flow – , m 3 /s (1.7),

Dust concentration in the air in front of the dust collector – g/m3 (2.68).

The dispersed composition of dust in the air in front of the dust collector is (see Table 7).

The median diameter of dust particles is , µm (35.0).

Dispersion of particle size distribution – (0.64),

Density of dust particles – , kg/m 3 (3700).

When choosing CN type cyclones as a dust collector, the following parameters are used (Table 8).

aspiration conveyor hydraulic duct

Table 8. Hydraulic resistance and efficiency of cyclones

Parameter
µm – diameter of particles captured by 50% in a cyclone with a diameter of m at air speed, dynamic air viscosity Pa s and particle density kg/m 3
M/s – optimal air speed in the cross section of the cyclone
Dispersion of partial purification coefficients –
The coefficient of local resistance of the cyclone, related to the dynamic air pressure in the cross section of the cyclone, ζ c:
for one cyclone
for a group of 2 cyclones
for a group of 4 cyclones

Permissible concentration of dust in the air, emitted into the atmosphere, g/m 3

At m 3 /s (37)

At m 3 /s (38)

Where the coefficient taking into account the fibrogenic activity of dust is determined depending on the value of the maximum permissible concentration (MAC) of dust in the air working area:

MPC mg/m 3

Required degree of air purification from dust, %

(39)

Estimated degree of air purification from dust, %

where is the degree of air purification from dust j-th fractions, % (fractional efficiency - taken according to reference data).

Disperse composition of many industrial dusts (at 1< <60 мкм) как и пофракционная степень их очистки и инерционных пылеуловителю подчиняется логарифмически нормальному закону распределения, и общая степень очистки определяется по формуле :

, (41)

in which

, (42)

where is the diameter of particles captured by 50% in a cyclone with a diameter of Dc at an average air speed in its cross section,

, (43)

– dynamic coefficient of air viscosity (at t=20 °C, =18.09–10–6 Pa–s).

Integral (41) is not resolved in quadratures, and its values ​​are determined by numerical methods. In table Figure 9 shows the function values ​​found by these methods and borrowed from the monograph.

It is not difficult to establish that

, , (44)

, (45)

this is a probability integral, the tabulated values ​​of which are given in many mathematical reference books (see, for example,).

We will consider the calculation procedure using a specific make-up artist.

1. Permissible concentration of dust in the air after cleaning it in accordance with formula (37) with a maximum permissible concentration in the working area of ​​10 mg/m 3 ()

2. The required degree of air purification from dust according to formula (39) is

Such cleaning efficiency for our conditions (μm and kg/m3) can be ensured by a group of 4 cyclones TsN-11

3. Let us determine the required cross-sectional area of ​​one cyclone:

m 2

4. Determine the estimated diameter of the cyclone:

m

We select the closest from the normalized range of cyclone diameters (300, 400, 500, 600, 800, 900, 1000 mm), namely m.

5. Determine the air speed in the cyclone:

m/c

6. Using formula (43), we determine the diameter of particles captured in this cyclone by 50%:

µm

7. Using formula (42), we determine the parameter X:

.

The obtained result, based on the NIOGAZ method, assumes a logarithmically normal distribution of dust particles by size. In fact, the dispersed composition of dust, in the region of large particles (> 60 microns), in the aspirated air for sheltering conveyor loading areas differs from the normal-logarithmic law. Therefore, it is recommended to compare the calculated degree of purification with calculations using formula (40) or with the methodology of the MOPE department (for cyclones), based on a discrete approach to what is fairly fully covered in the course “Mechanics of Aerosols”.

An alternative way to determine the reliable value of the overall degree of air purification in dust collectors is to install special experimental research and comparing them with calculated ones, which we recommend for an in-depth study of the process of air purification from particulate matter.

9. The concentration of dust in the air after cleaning is

g/m 3,

those. less than acceptable.

Requirements for labor protection and environmental conditions environment around existing enterprises are constantly increasing. Cleaning systems are also being improved. This article briefly discusses the aspiration process, types of systems and operating principles.

An aspiration system is a type of air filtration and purification used in production workshops with highly polluted technological processes.

First of all, these are metallurgical, mining, paint and varnish, furniture, chemical and other hazardous industries. The main difference between aspiration and air ventilation is that contaminants are collected directly at the workplace; global distribution throughout the workshop is not allowed.

Typical aspiration system design

Schematically, the design of the aspiration system includes:

1. A fan that creates an air flow and sucks in air. Cyclone-type installations are used, within which centrifugal force is created. It attracts large particles of contaminants to the walls of the device body. This is how the initial rough cleaning is performed.
2. Chip catchers for collecting large waste.
3. Filter elements various designs installed to clean the air from the smallest contaminants. The most productive installations consist of several types of filters, both primary and subsequent fine cleaning. They capture and separate 99% of all particles larger than 1 micron.
4. Catching devices and containers in which contaminants are stored.
5. Connecting air ducts and pipes that are installed at an angle to prevent clogging with solid contaminants.

Waste different types production differ in their physical and chemical properties, density and mass. Therefore, for each enterprise, the aspiration system is developed individually and includes the necessary elements. Only with this approach you will get effective cleaning air.

Types of aspiration units

The whole variety of aspiration systems is usually classified according to several criteria:

By degree of mobility

According to the method of outputting the filtered air flow

• Straight-through. After cleaning, the air is removed outside the room. Such systems are more efficient and environmentally friendly.
• Recirculation. Purified and warm air masses are released into the workshop. The main advantages of such systems: reduced costs for heating and air humidification, less load on the overall forced ventilation workshops

Calculation of equipment for the aspiration system

Correct calculation of equipment parameters is the main guarantee efficient work aspiration unit. The calculations are complex, since it is necessary to take into account many factors for each individual enterprise. Therefore, only highly qualified specialist engineers should perform such work. The main factors that need to be taken into account when designing an aspiration system:

• the speed of air movement in the system, which depends on the material of the air duct;
• area and volume of the room;
• air humidity and temperature;
• nature and intensity of pollution;
• duration of the work shift.

Based on the data obtained, the main parameters of the system are determined and calculated:

• the bandwidth of each individual device;
• required type of filters, their performance;
• the diameter of the air duct pipe, and it can be different for each production site;
• the points and location of the air duct are designed.

Features of installation and maintenance

To install the aspiration unit, it is not necessary to change the layout of the main equipment or the sequence technological process. Properly designed custom-made aspiration systems take into account all the production features and are integrated into an existing system.

The efficiency and speed of aspiration of the unit significantly reduces leaky connections. Therefore, it is important not only to install the system, but also to regularly carry out technical inspections and measures aimed at preventing connection breaks, and to eliminate identified defects in a timely manner. This will increase the productivity of the installation and reduce energy consumption during its operation.

There is no point in saving on the design and implementation of aspiration systems. Questionable equipment or improperly designed installation can lead not only to increased illness among workers and decreased productivity, but also to plant closure.

Installation of an aspiration system is a mandatory and necessary technical procedure in any modern enterprise. In addition, it is part of the production culture. Industrial aspiration not only improves the microclimate in production premises, but also prevents environmental pollution outside the walls of the plant or factory.

Let us consider the fundamental aspiration transport and technological systems of construction industry enterprises. The composition of the equipment for the bulk raw materials acceptance line includes a hopper, a conveyor, a bucket elevator, and a conveyor. Dust-air flows are formed mainly in the following sections: bunker - conveyor, conveyor - elevator, elevator - gravity pipeline at the elevator - chain conveyor section. Accordingly, zones of high and low air pressure are formed in shelters.

In Fig. 2.3 shows a diagram of the connection to the aspiration system of the equipment of the soupy raw materials receiving area.

Air suction can be carried out in two ways: the first is to connect all places of high pressure to the aspiration network: bunker, conveyor, elevator, chain conveyor; the second is to connect the hopper, shoe and elevator head, and conveyor to the aspiration network. With the second method, the length of the air ducts is significantly reduced, and the amount of dust entrained by the aspiration air duct is reduced, which makes the second method preferable.

For our example, the living area of ​​the grid above the receiving hopper should be kept to a minimum. Only those areas through which bulk material from vehicles enters the receiving hopper should be open. To reduce the contact area of ​​the falling flow of material with air and reduce the volume of ejected air, folding sealing shields should be used.

Fig. 2.3 Diagram of connection to the aspiration system of the equipment of the railway car unloading area: 1 - railway car; 2 - bunker; 3 – conveyor; 4 – elevator; 5 - chain conveyor; 6 - aspiration network; 7- sealing shields.

The volume of aspirated air from the receiving hopper is determined by the formula for the balance of air inflow and air flow

With a maximum mass flow of material of 100 t/h and a fall height of 2 m, see Table. 2.1 Le = 160 m³/h; vn - air speed in the holes, 0.2 m/s; Fn – leakage area of ​​the receiving hopper, 3 m²; Gm – volumetric mass of the material, 46 m³; t – unloading time, 180 s; we get:

La bun = 160 + ((0.2 * 3)*3600) + ((46 / 180)*3600) = 3240 m³/h

The values ​​of the volumes of aspirated air from the NTs-100 elevator (working and idle pipes) and the TSC-100 chain conveyor are obtained from regulatory documentation:

La no. work = 450 m³/h; La no. cold = 450 m³/h; La chain = 420 m³/h;

For the entire suction system:

La = 3240 + 450 + 450 + 420 = 4560 m³/h;

The pressure value in the aspiration pipe of the receiving hopper, taking into account the ejection pressure created by the bulk material at a fall height of 2 m and a bulk tray, is:

On bun = 50 + 50 = 100Pa

The pressure in each of the aspiration pipes of the elevator, taking into account the jet pressure in the discharge box of the conveyor, is:

At nor = 30 + 50 = 80Pa

The pressure in the aspiration pipe of the chain conveyor, taking into account the ejection pressure in inclined gravity flow up to 2 m and vacuum in the hopper, is:

On flail = 50 + 50 + 30 = 130Pa

Having received the initial data and configured the aspiration system, we will perform an aerodynamic calculation of the system performance

La = 4560 m³/h; see fig. 2.3, which we display on the workshop plan in the following sequence:

1. Air ducts and other elements of the aspiration system are drawn onto the floor plan, followed by the construction of a spatial (axonometric) aspiration diagram.

2. The main direction of air movement is selected. The main direction is considered to be the most extended or loaded direction from the fan to the starting point of the first section of the system.

3. The system is divided into sections with constant flow air, sections are numbered starting from the one furthest from the fan, first along the main line, and then along the branches. Determine the length of sections and air flow and enter these values ​​into Table 2.3, columns 1, 2, 3.

4. We preset the approximate air speed v or, m/s, in section 1 of the air duct (depending on the air speed for a given dust, see Table 2.4). Based on the planning requirements, we take the shape of the air duct and the material from which it is made (round, galvanized steel). The pressure loss in the chain conveyor connected to section 1 is entered in the table. 2.3 first line. To determine the pressure loss in section 1, we connect with a straight line according to the nomogram in Fig. 2.5 points Lchain=420 m³/h and v=10.5 m/s at the intersection of this line with the scale D we find the nearest smaller recommended diameter D = 125 mm, values v=10.5 m/s, Hd =67 Pa, λ/D=0.18 are entered in columns 3, 6, 8.

5. We sum up the local resistance coefficients on the section (tees, bends, etc.) selected by . We write the obtained result Σ ζ in column 5.

6. We perform multiplication, ( 1 * λ/D) fill in column 9, addition ( 1 * λ/D + Σ ζ) fill in column 10. Column 11 (total losses in the section) is found as the product of the values ​​​​recorded in columns 6 and 10. In column 12 we write the sum of the total losses in section 1 and pressure losses in the chain conveyor.

We carry out calculations of the remaining main sections in the same way.

7. At the end of the calculations, we sum up the obtained values ​​and obtain the total pressure loss in the network, which serves as a criterion for selecting a fan.

8. Having calculated the pressure loss along the main line, we proceed to calculate the pressure loss on the branches. When calculating which it is necessary to link, the discrepancy is allowed no more than 10%.

9. There are two ways to increase pressure losses in branches. The first method is to install additional local resistance (valve, diaphragm, washer) in the branch. The second method is to reduce the diameter of the branch.

In the example under consideration, the resistance of the 7th section should be increased by Hc = 237 - 186.7 = 50.3 Pa, and the 8th by - Hc = 373 - 187.7 = 185.3 Pa, and the 9th by - Ns = 460 - 157.8 = 302.2 Pa. In areas 7 and 8 this can be done by installing additional local resistance because The pipe diameter is already 125 mm. The value of the resistance coefficient of the diaphragm installed in section 7 is determined by the expression:

ζd7 = Ns / Nd7 = 50.3 / 74.1 = 0.68 (2.10)

According to this value in Fig. 2.4 we determine the depth of immersion of the diaphragm into the air duct to its diameter - a / D = 0.36, with D = 125 mm a = 43.75 mm. Similarly for sections 8 and 9: ζд8 = Нс / Нд8 = 185.3 / 74.1 = 2.5 according to Fig. 5.3 we determine - a / D = 0.53, with D = 125 mm a = 66.3 mm; ζd9 = Ns / Nd9 = 302.2 74.1 = 4.1 according to Fig. 2.3 we determine - a / D = 0.59, with D = 315 mm a = 186 mm;

Rice. 2.4 Single-sided diaphragm (a) and double scale for calculating dimensions (b)

Fig. 2.5 Nomogram by A.V. Panchenko for calculating air ducts.

Table 2.3

Aerodynamic calculation of air ducts.

Main sections

Plot number and name. cars	L m³/s	v m/s	l, m	Σ ζ	Hd, Pa	D, mm	λ/D	l*λ/D	l* λ/D+Σζ	Nature full pressure of the unit, Pa	Total pressure of the section, Pa
Chain Conv.	0,12	-	-	-	-	-	-	-	-
School 1	0,12	10,5		0,7			0,18	0,9	1,6
School 2	0,242	10,5		0,3			0,12	0,36	0,69
School 3	0,37			0,6	74,1		0,09	0,63	1,18	87,4	460,4
School 4	1,27	11,8		0,1	88,2		0,04	0,31	0.4	34,8	495,2
School 5	1,27	11,8		0,6	88,5		0,04	0,36	0.57	50,5	545,6
Pumping Unit 6	1,27	11,8			88,5		0,04	0,31	1,32	116,4	116,4

branches
Noria	0,125	-	-	-	-	-	-	-	-
Section 7	0,125			0,23	74,1		0,17	1,21	1,44	106,7	186,7
Noria	0,125	-	-	-	-	-	-	-	-
Section 8	0,125			0,2	74,1		0,17	1,25	1,45	107,7	187,7
Receiving hopper	0,9	-	-	-	-	-	-	-	-
Section 9	0,9			0,18	74,1		0,06	0,6	0,78	557,8	157,8

Table 2.4 Values ​​for the design of aspiration and pneumatic transport systems

Transported material	ϒ, kg/m 3	Air movement speed in air ducts v, m/s	Maximum mass concentration of the mixture μ kg/kg	Experienced coefficient TO
vertical	horizontal
Earth and sand dust, recycled (burnt) earth, molding earth				0,8	0,7
The earth and sand are wet				‒	‒
Ground clay				0,8	0,6
Chamotte				0,8	0,6
Fine mineral dust	‒			‒	‒
Dust from cloth polishing wheels	‒			‒	‒
Coal dust	900‒1000
Mineral emery dust		15,5		‒	‒
Gypsum, finely ground lime				‒	‒
Wool:
oily	‒			‒	‒
unoiled	‒			‒	‒
artificial	‒			‒	‒
merino (oiled and unoiled)	‒			0,1‒0,2	‒
flap	‒			‒	‒
loosened and large fuzz	‒			‒	‒
Flax:
short fiber	‒			‒	‒
flax fire	‒			‒	‒
Sheaves trusts	‒			0,5	‒
Raw cotton, loosened cotton, large cotton tow	‒			0,5	‒
Sawdust:
cast iron				0,8	0,85
steel				0,8	‒
Coal slag with particle size 10 – 15 mm					0,5

To calculate the aspiration installation, it is necessary to know the location of the aspirated equipment, fans, dust collectors and the location of the air duct route.

From the drawings general view installation, we draw up an axonometric diagram of the network without scale and enter all the data for the calculation on this diagram. We divide the network into sections and determine the main highway and side parallel sections of the network.

The main highway consists of 7 sections: AB-BV-VG-GD-DE-EZH-ZZ; and has 4 lateral ones: aB, bV, vg, dg and gG.

The calculation results are summarized in table A.1 (Appendix 1).

Section AB

The section consists of a confuser, a straight vertical section 3800 mm long, a 30° bend, and a straight horizontal section 2590 mm long.

The air speed in section AB is assumed to be 12 m/s.

Consumption - 240 m3/h.

We accept standard diameter D=80 mm. The cross-sectional area of ​​the duct of the selected diameter is 0.005 m2. We specify the speed using the formula:

where S is the cross-sectional area of ​​the air duct, m2.

Pressure loss along the length of the air duct is determined by the formula:

where R is the pressure loss per meter of duct length, Pa/m.

Estimated length of the section, m.

By diameter D and speed v, according to the nomogram, we find the pressure loss per meter of air duct length and dynamic pressure: R = 31.4 Pa/m, Nd = 107.8 Pa

We determine the dimensions of the confuser inlet opening based on the area of ​​the inlet opening using the formula:

Where vin is the speed at the entrance to the confuser; for flour milling dust we will take 0.8 m/s.

We find the length of the confuser (suction pipe) using the formula:

where b is the largest size of the confuser on the suction machine,

d-duct diameter,

b - angle of narrowing of the confuser.

The resistance coefficient of the confuser is determined from table. 8 depending on lk/D>1 ib=30o-tk=0.11.

We find the radius of the outlet using the formula:

where n is the ratio of the bend radius to the diameter, we take 2;

D-diameter of the duct.

Ro=2·80=160 mm

The length of the bend is calculated using the formula:

Branch length at 30°:

Estimated length of section AB:

LAB=lk+l3o+Ulpr

LAB=690+3800+2590+84=7164 mm

We find the pressure loss in the AB section using formula 12:

RlАБ=31.4·7.164=225 Pa

Section aB

Section aB consists of a confuser, a straight vertical section 4700 mm long, a straight horizontal section 2190 mm long and a side section of the tee.

The air speed in section aB is assumed to be 12 m/s.

Consumption -360 m3/h.

We determine the required diameter using formula 8:

We accept standard diameter D=100 mm. The cross-sectional area of ​​the duct of the selected diameter is 0.007854 m2. We specify the speed using formula (10):

By diameter D and speed v, according to the nomogram, we find R = 23.2 Pa/m, Hd = 99.3 Pa.

Let's take one of the sides of the confuser b = 420 mm.

The resistance coefficient of the confuser is determined from table. 8 depending on lk/D>1 and b=30o-tk=0.11.

Ro=2·100=200 mm

We find the resistance coefficient of the 30° tap from Table 10.

Branch length at 30°

Estimated length of section aB:

LaB=lk+2·l9o+ Ulpr

LaB=600+4700+2190+105=7595 mm.

We find the pressure loss in section aB using formula 12:

RlaB=23.2·7.595=176 Pa

We find the resistance coefficients of the tee by specifying the diameter of the combined air duct D=125 mm, S=0.01227 m2.

The ratio of areas and costs is determined by the formula:

where Sp is the area of ​​the passage duct, m2;

Sb - side air duct area, m2;

S-air duct area of ​​combined flows, m2;

Lb - side air duct flow rate, m3/h;

L-air duct flow rate of combined flows, m3/h.

The ratio of areas and costs is determined by formulas (18):

The resistance coefficient of the tee is determined from Table 13: passage section zhpr = 0.0 and side section rbk = 0.2.

Hpt=Rl+UtHd

The pressure loss in the AB section is:

Npt.p=225+(0.069+0.11+0.0)107.7=244 Pa

The pressure loss in section aB is:

Npt.b=176+(0.069+0.11+0.2)99.3=214 Pa

UNpt.p=Npt.p+Nm.p.=244+50=294 Pa,

where Nm.p.=50.0 Pa - pressure loss in the hopper from the table. 1.

UNpt.b=Npt.b+Nm.b.=214+50.0=264 Pa,

where Nb.p. = 50.0 Pa - pressure loss in burat from the table. 1.

Pressure difference between sections AB and AB:

Ndiaf=294-264=30 Pa

Since the difference is 10%, there is no need to equalize losses in the tee.

BV section

The section consists of a straight horizontal section with a length of 2190 mm, a through section of the tee.

Consumption - 600m3/h.

The diameter of the air duct in the BV section is 125 mm.

Based on the diameter D and speed v according to the nomogram, we find R=20 Pa/m, Nd=113 Pa.

Estimated length of the waste water section:

RlБВ=20.0·2.190=44 Pa

Section bV

Section bV consists of a confuser, a straight vertical section 5600 mm long and a side section of a tee.

The air speed in section bV is assumed to be 12 m/s.

Consumption -1240 m3/h.

We determine the required diameter using formula 8:

We accept standard diameter D=180 mm. The cross-sectional area of ​​the duct of the selected diameter is 0.02545 m2. We specify the speed using formula (10):

According to the diameter D and speed v, according to the nomogram, we find R = 12.2 Pa/m, Nd = 112.2 Pa.

We determine the dimensions of the confuser inlet hole based on the area of ​​the inlet hole using formula 13:

Let's take one of the sides of the confuser b=300 mm.

We find the length of the confuser (suction pipe) using formula 15:

The resistance coefficient of the confuser is determined from table. 8 depending on lk/D>1 and b=30o-tk=0.11.

We find the radius of the outlet using formula 15

Ro=2·180=360 mm

We find the resistance coefficient of the 30° tap from Table 10.

We calculate the length of the bend using formula 16.

Branch length at 30°

Estimated length of section bV:

LaB=lk+l30o+ Ulpr

LbV=220+188+5600=6008 mm.

We find the pressure loss in section bB using formula 12:

RlБВ=12.2·6.008=73 Pa.

We find the resistance coefficients of the tee by specifying the diameter of the combined air duct D=225 mm, S=0.03976 m2.

The resistance coefficient of the tee is determined from Table 13: passage section zhpr = -0.2 and side section rbk = 0.2.

Pressure loss in the area is calculated using the formula:

Hpt=Rl+UtHd

The pressure loss in the BW section is:

Npt.p=43.8-0.2113=21.2 Pa

The pressure loss in section bB is:

Npt.b=73+(0.2+0.11+0.069)112.0=115 Pa

Total losses in the passage section of the BV:

UNpt.p=Npt.p+Nm.p.=21.2+294=360 Pa,

Total losses on the side section:

UNpt.b=Npt.b+Nm.b.=115+80.0=195 Pa,

where Nb.p. = 80.0 Pa - pressure loss in the aspiration column from Table 1.

Pressure difference between the BV and BV sections:

Since the difference is 46%, which exceeds the permissible 10%, it is necessary to equalize the pressure losses in the tee.

Let's perform the alignment using additional resistance in the form of a side diaphragm.

We find the diaphragm resistance coefficient using the formula:

Using the nomogram we determine the value 46. Where does the depth of the diaphragm come from a=0.46·0.180=0.0828 m.

VG section

The VG section consists of a straight horizontal section 800 mm long, a straight vertical section 9800 mm long, a 90° bend and a side section of the tee.

The air speed in the VG section is assumed to be 12 m/s.

Consumption - 1840 m3/h.

We accept standard diameter D=225 mm. The cross-sectional area of ​​the duct of the selected diameter is 0.03976 m2. We specify the speed using formula (10):

By diameter D and speed v, according to the nomogram, we find R = 8.0 Pa/m, Hd = 101.2 Pa.

We find the radius of the outlet using formula 15

Ro=2·225=450 mm

We find the resistance coefficient of the 90° tap from Table 10.

We calculate the length of the bend using formula 16.

90° bend length

Estimated length of the VG section:

LВГ=2·l9o +Улр

LВГ=800+9800+707=11307 mm.

RlВГ=8.0·11.307=90 Pa

Section VG

Section vg consists of a confuser, a 30° bend, a vertical section 880 mm long, a horizontal section 3360 mm and a tee through section.

Consumption - 480 m3/h.

We determine the dimensions of the confuser inlet hole based on the area of ​​the inlet hole using formula 13:

The resistance coefficient of the confuser is determined from table. 8 depending on lk/D>1 and b=30o-tk=0.11.

Ro=2·110=220 mm

We find the resistance coefficient of the 30° tap from the table. 10.

We calculate the length of the bend using formula 16.

Branch length at 30°

Estimated section length vg:

Lвг=lk+l30+ Улр

lвг=880+115+300+3360=4655 mm.

The pressure loss in the section vg is found using formula 12:

Rlgv=23·4.655=107 Pa

Section dg

The dg section consists of a confuser, a straight vertical section 880 mm long and a side section of the tee.

Consumption -480 m3/h.

We choose a speed of 12 m/s. We determine the required diameter using formula 8:

We accept standard diameter D=110 mm. The cross-sectional area of ​​the duct of the selected diameter is 0.0095 m2. We specify the speed using formula 10:

According to the diameter D and speed v, according to the nomogram, we find R = 23.0 Pa/m, Hd = 120.6 Pa.

We determine the dimensions of the confuser inlet hole based on the area of ​​the inlet hole using formula 13:

Let's take one of the sides of the confuser b=270 mm.

The length of the confuser (suction pipe) is found using formula 14:

The resistance coefficient of the confuser is determined from table. 8 depending on lk/D>1 and b=30o-tk=0.11.

Estimated section length vg:

Lвг=lk+l30+ Улр

lвг=880+300=1180 mm.

The pressure loss in the section vg is found using formula 12:

Then, pressure loss along the length of the air duct:

Rlgv=23·1.180=27.1 Pa

We find the resistance coefficients of the tee by specifying the diameter of the combined air duct D=160 mm, S=0.02011 m2.

The ratio of areas and costs is determined by formula 18:

The resistance coefficient of the tee is determined from Table 13: passage section zhpr = 0.0 and side section rbk = 0.5.

Pressure loss in the area is calculated using the formula:

Hpt=Rl+UtHd

The pressure loss in the section vg is:

Npt.p=107+(0.069+0.11+0.0)120.6=128 Pa

The pressure loss in the dg section is:

Npt.b=27+(0.11+0.5)120.6=100 Pa

Total losses in the passage and side sections:

UNpt.p=Npt.p+Nm.p.=128+250=378 Pa,

UNpt.b=Npt.b+Nm.b.=100+250=350 Pa,

where Nm.p. = 250.0 Pa - pressure loss in the trireme from the table. 1.

Pressure difference between sections vg and dg:

Ndiaf=378-350=16 Pa

Since the difference is 7%, which does not exceed the permissible 10%, there is no need to equalize pressure losses in the tee.

Section GG

The section consists of straight horizontal sections 2100 mm long, and a through section of the tee.

The flow rate of the GG section is equal to the sum of the costs in the VG and DG sections.

Consumption -960 m3/h.

The diameter of the air duct in the section GG is 160 mm.

The cross-sectional area of ​​the air duct of the selected diameter is 0.02011 m2.

We specify the speed using formula 10:

By diameter D and speed v, according to the nomogram, we find R = 14.1 Pa/m, Nd = 107.7 Pa

Estimated length of section GG:

LgG=2100 mm.

Pressure loss along the length is found using formula 12:

RlгГ=14.1·2.1=29.6 Pa

We find the resistance coefficients of the tee by specifying the diameter of the combined air duct D=250 mm, S=0.04909 m2.

The ratio of areas and costs is determined by formula 18:

The resistance coefficient of the tee is determined from Table 13: passage section zhpr = 0.2 and side section rbk = 0.6.

Pressure loss in the area is calculated using the formula:

Hpt=Rl+UtHd

The pressure loss in the VG section is:

Npt.b=90+(0.15+0.2)101.2=125.4 Pa

The pressure loss in the GG section is:

Npt.p=29.6+0.6·107.7=94.2 Pa

Total losses in the passage and side sections:

UNpt.p=Npt.p+Nm.p..=125.4+360.4=486 Pa,

UNpt.b=Npt.b+Nm.b =94.2+378=472 Pa,

Pressure difference between the VG and GG sections:

Ndiaf=486-472=14 Pa

The difference is less than 10%.

GD section

The plot consists of a straight horizontal section with a length of 1860 mm.

Consumption of the gas turbine section - 2800 m3/h

The diameter of the air duct in the GD section is 250 mm, S = 0.04909 m2.

We specify the speed using formula 10:

According to the diameter D and speed v, according to the nomogram, we find R = 11.0 Pa/m, Hd = 153.8 Pa.

The area of ​​the inlet to the cyclone is equal to the area of ​​the inlet pipe S2=0.05 m2

Estimated length of the main section:

lGD=1860 mm.

We find the pressure loss in the main pressure section using formula 12:

Then, pressure loss along the length of the air duct:

RlGD=11.0·1.86=20.5Pa

The pressure losses in the gas pressure section are:

UNpt.p=20+486=506 Pa

Section DE

Cyclone 4BTsSh-300.

Air consumption taking into account air suction:

The pressure loss in the cyclone is equal to the resistance of the cyclone and amounts to Hc = 951.6 Pa.

Total losses in the DE section:

Section EZH

The section consists of a confuser, three 90° bends, straight horizontal sections 550 mm and 1200 mm, a straight vertical section 2670 mm long, a straight horizontal section 360 mm and a diffuser.

We will determine the flow rate in the EJ section taking into account the suction in the cyclone equal to 150 m3/h:

The air speed after the cyclone is 10...12 m/s, since after the cyclone the air is purified.

The air speed in the EZh section is assumed to be 11 m/s.

We determine the required diameter using formula 8:

We accept standard diameter D=315 mm, S=0.07793 m2.

We specify the speed using formula 10:

According to the diameter D and speed v, according to the nomogram, we find R = 3.8 Pa/m, Hd = 74.3 Pa.

The area of ​​the inlet in the transition pipe is S1 = 0.07793 m2, and the area of ​​the cyclone outlet is S2 = 0.090 m2, since S1

Let's take one of the sides of the confuser b=450 mm.

We find the length of the confuser using formula 15:

The resistance coefficient of the confuser is determined from table. 8 depending on lк/D=0.6 and b=30о - tk=0.13.

It is necessary to determine whether the adapter pipe at the fan inlet is a confuser or a diffuser.

Since the outlet pipe has a diameter of 315 mm, and the diameter at the fan inlet is 320 mm, the adapter pipe is a diffuser with an expansion ratio:

We find the radius of the outlet using formula 15:

We find the resistance coefficient of the 90° tap from the table. 10.

We calculate the length of the bend using formula 16:

Estimated length of the EZh section:

LEF=989.6*3+2670+360+1200+550=7749 mm.

RlEZh=3.78·7.749=29 Pa.

UNpt.p=1458+29+(0.13+0.1+0.15·3)74.3=1538 Pa.

Section ZhZ

The section consists of a diffuser, a straight vertical section 12700 mm long, a 90-degree bend and a diffuser with a protective umbrella.

The air flow in this area is equal to the flow at the entrance to the fan, i.e. 3090m3/h.

Air speed is 11.0 m/s.

The diameters of the air ducts in the sections are assumed to be equal to the diameter upstream of the fan, i.e. 315mm.

By diameter D and speed v, according to the nomogram, we find R = 3.8 Pa/m, Nd = 68.874.3 Pa.

Let's determine what the adapter pipe at the outlet of the fan serves.

Fan opening area S1=0.305x0.185=0.056 m2, cross-sectional area of ​​the air duct with a diameter of 315 mm S2=0.07793 m2.

S2>S1, therefore there is a diffuser with an expansion ratio:

Let's set the diffuser expansion angle b=30?. Then from the table. 4 diffuser resistance coefficient w=0.1.

Estimated length of the EZh section:

lEZh=12700 mm.

Pressure loss along the length of the air duct is determined by formula 11:

RlEZh=3.78·12.7=48.0 Pa.

The pipe has a diffuser with a protective umbrella.

The loss coefficient is found in table. 6 f = 0.6.

The pressure loss in the EF section is:

UNpt.b=48+(0.1+0.6)74.3=100 Pa.

The total network resistance along the main line is:

UNpt.p=100+1538=1638 Pa.

Taking into account the safety factor of 1.1 and the possible vacuum in the workshop premises, the required pressure developed by the fan is 50 Pa.

Production processes are often accompanied by the release of dust-like elements or gases that pollute the indoor air. The problem will be solved by aspiration systems designed and installed in accordance with regulatory requirements.

Let's figure out how such devices work and where they are used, what types of air purification systems there are. We will designate the main working units, describe the design standards and rules for installing aspiration systems.

Air pollution is an unavoidable part of many production processes. To comply with the established sanitary standards air purity, use aspiration processes. With their help, you can effectively remove dust, dirt, fibers and other similar impurities.

Aspiration is suction, which is carried out by creating an area of ​​​​low pressure in the immediate vicinity of the source of contamination.

To create such systems, serious specialized knowledge and practical experience are required. Although the operation of aspiration equipment is closely related to the operation, not every ventilation specialist can handle the design and installation of this type of equipment.

To achieve maximum efficiency combine ventilation and aspiration methods. Ventilation system the production area must be equipped to ensure a constant supply fresh air outside.

Aspiration is widely used in the following industries:

• crushing production;
• wood processing;
• manufacturing of consumer products;
• other processes that are accompanied by the release of large amounts of substances harmful to inhalation.

It is not always possible to ensure the safety of employees using standard protective equipment, and aspiration may be the only opportunity to establish safe production process in the workshop.

Aspiration units are designed to effectively and quickly remove various small contaminants from the air that are formed during industrial production.

Removal of contaminants using systems of this type is carried out through special air ducts that have high angle tilt This position helps prevent the appearance of so-called stagnation zones.

Mobile ventilation and aspiration units are easy to install and operate, they are perfect for small businesses or even for a home workshop

An indicator of the effectiveness of such a system is the degree of non-knocking out, i.e. ratio of the amount of contaminants that were removed to the mass harmful substances, not included in the system.

There are two types of aspiration systems:

• modular systems– stationary device;
• monoblocks– mobile installations.

In addition, aspiration systems are classified according to pressure level:

• low-pressure– less than 7.5 kPa;
• medium pressure– 7.5-30 kPa;
• high-pressure– over 30 kPa.

Complete set of aspiration system modular and monoblock type different.

In hot shops, heating the air coming from outside is not necessary; it is enough to make an opening in the wall and close it with a damper.

Conclusions and useful video on the topic

Here's an overview of the unboxing and installation mobile system RIKON DC3000 aspiration for the woodworking industry:

This video demonstrates a stationary aspiration system used in furniture production:

Aspiration systems – modern and reliable way air purification in industrial premises from dangerous pollution. If the structure is properly designed and installed without errors, it will demonstrate high efficiency at minimal cost.

Do you have anything to add or have any questions about aspiration systems? Please leave comments on the post. The contact form is located in the lower block.