Air pollution in industrial enterprises

Airborne pumps

basic principle of ventilation

Centrifugal exhaust veshilyatory

Determination of air exchange

dust control

Exhaust System

Forced ventilation on confectionery

Hourly values

mist of water vapor

pressure loss in the flare emissions

radioactive dust

scheme of the central pressure inlet system

Special prechamber

temperature gradient

Ventilation at bakeries

Ventilation in the Confectionery Factory

ventilation when dealing with heat

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formulas, which include the value of WM

Formulas, which include the value of WM, suitable for installation performance of more than 50 m3 / h. For plants less productivity may use these formulas, provided the substitution in these quantities WM = 50 m3 / h.

The volume of air Lu, prosasyvaemogo vented through the chamber and the density in shelters such as SIOT on conveyors, it is recommended to determine the formula (61)

5400 LH = vk (0,7 / k - 0,5 / n + 0,4,),

where

cross-sectional area of one side of the ventilated chamber in m (Table 11);

The area of the leaks in the front end wall of the shelter in m2;

- The area of leaks in the rear end wall of the shelter in m2;

• coefficient depending on the conditions of receipt, with receipt of material from the conveyor or the roar of Ny = l, on admission of the grinders 7Vy = 1,3.

Bearing in mind the effective action of suction type SIOT, you should take the area f0 each of the holes, connecting the side vented chamber with an internal cavity cover, equal to 0,4 fKi3 / 4

The numerical coefficient in the formula (61) takes into account the inaccuracy of manufacturing such shelters SIOT PA practice, and a possible increase in density did not cover during the operation.

Here are two examples of determining the volume of exhausted air to shelters such as La SIOT on conveyors.

There is pouring (difference) from the conveyor onto the conveyor under the following conditions: the number of ore в„– "= 250 m3 / h speed tape 1, 25 m / sec, belt width 800 mm drop height of material in the boot estrus 3 m, the slope of oestrus to horizon of 90 В°.

Take shelter type SIOT ribbon 800 mm wide (Table 11) for which f '= 0.04 m2 / n = 0.03 m2 / 3 = 0,01 m2 (shelter no-go).

The velocity of the material at the entrance to the shelter vK - 19lZ-z7T-2D65 = 0) .= / 588 7.7 g / sec. The amount of air introduced by the incoming material (L \ - -1,2),

L3 = 0,12-1,2-250-7,72 2100 m3! Pm

The amount of air through prosasyvaemogo ventilated chamber and leaks shelter (Ny = \).

determined by the formula (61): L "- 5400-7,7 (0,7-0,04 + 0,5-0,03 + 0,4-0,01) -1 =. 2000 m3 / h.

The total amount removed from the shelter air La = 2100 + 2000 =- 4100 Martyrs.

Should adopt a rounded = 4000 m / h.

In the second example, consider shelter na pipeline that takes the material from the jaw crusher. Conditions remain the same, according to shelter SIOT adopted through passage and, therefore,

/ 1 = 0,04 m 2, fn = 0,05 mg, f3 = 0,05 mg.

The amount of air introduced by the incoming material (Ku ~ = 1,8),

L3 = 0,12-1,8 -250 - 7,72 = 3,200 Martyrs. The amount of air through prosasyvaemogo ventilated chamber and leaks shelter (A \ = 1,3), LH = 5400-7,7 (0,7-0,04 + 0,5-0,05 + 0,4-0,05 ) -1,3 = 3900 m3 / h.

total amount removed from the shelter air La = 3200 + 3900 = 7100 m3 / h.

Should adopt a rounded La = 7000 m3 / h.

Calculate the volume of air removed from the shelter type SIOT should be considered minimally acceptable, provided a very thorough run shelters and thorough exploitation. These figures for shelter type SIOT na conveyors are neutral dust. For other pylsy, as already mentioned, it is necessary to introduce the coefficient of [-1, greater than unity. When using formulas (60) and (61) should be a minimum width of the tape? = 0,5 m. Recalculate the second example above, provided that the assembly line set-through cover with no side-ventilated chambers.

The amount of air introduced by the incoming material (Ku = = 2,4),

L9 = 0,12-2,4-250.7,72 = 4200 m3 / h.

The amount of air through prosasyvaemogo not density (A = 750: C 1; AU - 1,4), but we define (60):

LH - 750 -! -0,82-7,7-1,4 * 5200 m / h.

The total amount of air exhausted La = 4200 + 5200 = 9400 m3! Pm

Should adopt a rounded L = 10 000 m3 / h.

Compared with shelter type SIOT air volume increased to 3000 m3 / h, ie about 43%.

Consider the crusher for the second and third stages of crushing capacity в„– "= 300 m 3 [h The installation consists of a cone crusher secondary crushing (D = = 2,2 m), inertial din size in terms of 1,8 x3, 5 m, a crusher of fine crushing and outfeed with ribbon width B = m. The first crushing load plate feeder the second estrus with an average angle "= 60 В°, the height of the fall / 7 = 3 m. After screening 1 / 3 of the material (100 m3 / h) goes directly to the conveyor to a shelter with no side-ventilated chambers. Performance of the crusher of fine crushing 200 m3 / h, material from the crusher arrives on the conveyor in a shelter type SIOT (/ = 2,5 m '= 90 В°).

Aspiration, followed by gidroobespylivannem, the required air down. With hydrophilic materials under favorable conditions may decrease the volume of aspiration, even by half. Give any advice on this matter is not yet possible. Tentatively, we can assume that the average gidroobespylivanie without significant dampening material results in reduced volume of air removed by aspiration at 20-40%, but it mainly depends on the properties of the dust-processed material.

Determination of the volume of air, remove dust extraction ventilation of the cabinet, showcase, etc. The shelters, as well as shelters, completely closing dusting machine, is similar to that described above for the toxic pollutant (gas, vapor), ie, the formula

L = 3600 Fv \ m3 / h]. (62)

To account for accidental leaks in enclosures shelters in calculating the total area, as well as for gases, it is recommended to introduce a coefficient greater than unity. The values of this coefficient can be taken according to В§ 10.

Sometimes the load of dusty material in the device is made through an open funnel. For localization of dust emission slit arranged pumps. The volume of exhaust air shall be appointed on the basis of 7000 - 9000 m * / h type 1 m2 of open funnel.