The dye­ing cham­ber is a fair­ly clean and air­tight room, which is nec­es­sary for the dye­ing process of var­i­ous objects and prod­ucts. The oper­at­ing con­di­tions of such pro­duc­tion sug­gest the pres­ence of severe air pol­lu­tion with vapors of dyes and sol­vents. To ensure the qual­i­ty of work per­formed and the safe­ty of the health of the oper­a­tor, good ven­ti­la­tion is nec­es­sary in such a box.

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Types of ventilation systems

Any sup­ply and exhaust sys­tem for paint­ing rooms should pro­vide high-qual­i­ty work in two modes: in the ven­ti­la­tion mode and in the dry­ing mode. In ven­ti­la­tion mode:

  • The sup­ply ven­ti­la­tion of the spray booth should pro­vide this room with puri­fied and heat­ed air up to 30 ° C.
  • The hood should pro­vide a uni­form intake of air mass­es from the paint­ing room, clean­ing from con­t­a­m­i­nants and remov­ing the cleaned air mass­es into the atmos­phere.

In this mode, at least 40 times the air exchange should be pro­vid­ed. A much larg­er mul­ti­plic­i­ty can also be used so as not to exceed the MPC of tox­ic vapors of sol­vents used in paint­ing. More­over, the sup­ply of fresh air flow should be car­ried out from the top of the paint­ing room. The intake of air mass­es should be car­ried out from the bot­tom of the box along its entire perime­ter.

In the dry­ing mode, the ven­ti­la­tion sys­tem must sup­ply fil­tered air heat­ed to 60 °C to the room.

There are two main types of room ven­ti­la­tion for such enter­pris­es:

  1. Sup­ply, with mechan­i­cal impulse. The inlet puri­fied air is sup­plied from the roof of the box, and the con­t­a­m­i­nat­ed air enters the fil­ter ele­ments through the holes in the floor and is released into the envi­ron­ment under the action of nat­ur­al draft.
  2. Mechan­i­cal, sup­ply and exhaust. It dif­fers from the sup­ply only in that the exhaust ven­ti­la­tion of the spray booth is done with a mechan­i­cal impulse.

It should be not­ed that the per­for­mance of the sup­ply fan must be high­er than the capac­i­ty of the exhaust fan. Due to this, excess pres­sure is cre­at­ed in the room, at which dust and oth­er mechan­i­cal impu­ri­ties can­not enter it through nat­ur­al cracks.

Filtration of air masses

The ven­ti­la­tion sys­tem of such indus­tries must be equipped with air fil­tra­tion, which includes:

  • A glass fiber fil­ter installed in the space above the ceil­ing to clean the air flows enter­ing the box.
  • Coarse pre-fil­ter ele­ments to extend the life of expen­sive fine fil­ter ele­ments.
  • Fine fil­ters, which are mount­ed direct­ly in the ceil­ing of the room
  • A card­board fil­ter that takes on all the con­t­a­m­i­nants when the air flow leaves the box.
  • Char­coal fil­ter for absorb­ing unpleas­ant odors from the air and its final clean­ing before being released into the atmos­phere.

Ventilation device in the paint shop

Calculation of air exchange and equipment performance

The cal­cu­la­tion of the per­for­mance of ven­ti­la­tion equip­ment for paint­ing box­es is car­ried out based on the vol­ume of the room and the fre­quen­cy of air exchange. The whole com­plex­i­ty of the cal­cu­la­tion lies in the fact that the rate of air exchange for ven­ti­la­tion of spray booths, SNiP does not reg­u­late in any way. The mul­ti­plic­i­ty val­ues ​​are cal­cu­lat­ed based on the MPC of sol­vents and aerosols in the air mass­es of the box when paint­ing and dry­ing the paint­ed prod­uct.

MPC for the sol­vents most used in col­or­ing:

  • Gaso­line — 5 mg / m3.
  • Xylene — 0.2 mg/m3.
  • Toluene — 0.6 mg / m3.
  • Ben­zene — 1.5 mg/m3.

The high­est max­i­mum allow­able con­cen­tra­tion of the sol­vent in the air is for the pen­tane sol­vent, the MPC val­ue for which is 100 mg / m3.

The speed of move­ment of air mass­es in such pro­duc­tion is cal­cu­lat­ed depend­ing on the tech­no­log­i­cal process and the MPC of aerosol com­pounds in the air. Accord­ing to the “Design­er’s Hand­book” part — 3 of 1992. under the edi­tor­ship of N.N. Pavlov and Yu.N. Schiller, when work­ing with the release of aerosols, the speed of move­ment of air mass­es should be at least 1.2 — 1.5 m / s.

The video shows the effec­tive oper­a­tion of the ven­ti­la­tion sys­tem:

Do-it-yourself ventilation for painting plants

After com­plet­ing the fin­ish­ing work and installing light­ing equip­ment, it was the turn to equip the garage for paint­ing, with a ven­ti­la­tion sys­tem.

  1. An air intake should be arranged under the ceil­ing. Air intake can be car­ried out using a heat gun with the required capac­i­ty.
  2. From the heat gun (under the ceil­ing), a net­work of flex­i­ble air ducts should be laid out with eight air sup­ply points, made even­ly around the entire perime­ter of the paint­ing box.
  3. Each inflow point should be direct­ed towards the cen­ter of the cham­ber.

The floor of the paint­ing room is the most impor­tant ele­ment of its ven­ti­la­tion sys­tem. It is made of per­fo­rat­ed met­al, through the holes of which the con­t­a­m­i­nat­ed air mass­es are pumped out.Arrangement of a perforated floor in a spray booth

To orga­nize the hood, you should:

  1. Raise the floor lev­el by 20 cm.
  2. Make a cen­tral part from a per­fo­rat­ed sheet of met­al or weld a lat­tice from a cor­ner and fit­tings.
  3. Install and seal an air duct under the floor to remove air mass­es from the room to the atmos­phere.

After com­plet­ing all these pro­ce­dures, you will make sure that do-it-your­self ven­ti­la­tion in the spray booth is quite dif­fi­cult, but quite pos­si­ble.

If you decide to make a paint­ing room with your own hands, then when cal­cu­lat­ing, be guid­ed by a 200-fold air exchange cre­at­ed by a sup­ply fan.

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