Determination air in cabins
Determination of air in the cabin in which encapsulation particularly harmful equipment, the calculation can not be. Number of emitted pollutant, as a rule, is unknown. Allowable concentrations of harmful substances in cabin air is not regulated. In the case of separation of explosive gases and vapors is only necessary to ensure the impossibility of explosive mixtures.
The volume of air that must be removed from the booths, is determined by the multiplicity of exchange. However, no rules in this case does not exist. We can assume that the multiplicity is less than 10 exchanges in 1 h is not accepted, even for large enclosures. On the other hand, is rarely taken the multiplicity of the exchange of more than 100 in 1 hour
In these limits and are practically acceptable multiplicity of exchanges.
As a first approximation, it is recommended to take a cab to kapsyulyatsii apparatus in the absence of these rights, with a significant saturation of equipment and highly toxic hazard (concentration of 1 mg/m3 or less), the following exchange in the multiplicity of 1 h:
small quantities (up to 100 m3). 60-100 average (up to 500 m3}... 50-80 velichny large (up to 1000 ms). 30-60
With less harmful substances, but when working under high pressure apparatus multiplicity of exchange can take 40-80 respectively for the small booths, 30-60 and 20-40 for medium to large.
When processing in the cockpits of large quantities of metallic mercury multiplicity of exchange should take at least 60-100.
Determination of air exchange to be removed by suction panels, is also produced by the formula flow
L = 3600 / and \ m31ch]. (28)
where - live cross bar in m2;
v - average speed (real) in the living section of the panel, in m / sec.
By the same formula calculates the slot suction and suction-funnel. However, for this kind of local suction there are other practical standards.