Packing crown should be made only in shelters with heavy aspiration. Ring pumps with pneumatic clamps bags are not applicable. It is important that spillage packed product remained in hiding and did not get on the floor of the room. Air velocity in the working opening shelters should take at least 2 m / sec.
Shelter packaging machine must be continuous and sufficiently capacious, with a working aperture for the installation and extraction bag. Sometimes filled bag is ejected from the shelter a special device. Shelter may be steel, but it is better to carry out organic glass. Dimensions of the working aperture usually 500x800 mm. The area of support apertures and slits is about 25% of the area of the working aperture (ratio <= 1.25).
Under these conditions, the amount of air removed from the shelter of packaging machines is
L: 3600-1,25 0,8-2 3600 m3 / h.
Cross-section of aspiration funnel at a rate of entrance than 1 m / sec
Shelter packaging machine is shown schematically in Fig. 37.
In sewing machine or a piece of hand sewing the bags should be installed as a local suction suction panel. Speed in the living section of the panel is taken up to 8 m / sec, depending on the location bar. If the size vertical panel 400x600 mm, and the living section of about 0.06 m2 volume of exhausted air will be
L = 3600 вЂў 0,06 вЂў August 1700 m3 / h.
The volume of air exhausted much more than the PA production of titanium pigment and lithopone.
Yet is still used in primitive crop drying shelf dryers with manual unloading - a phenomenon completely unacceptable: these dryers are sources of dust, as a result of spillage of the product on the floor Props walks secondary dust.
Shelving, dryer. Product placement sushim na trays still somehow acceptable when used carriages equipped with a device for emptying the bins by their overturning. The operation shall be discharged in a special CABINET STYLE shelter into which emptied trolley rolled. Overturning trays made at the closed door shelter. After emptying after some time the door opens and the car rolls. Then the process repeats again. Shelter is aspirated from the calculation of a speed in the open doorway of the order of 1 m / sec. A relatively small rate due to the fact that the time-intensive open the door - dust separation ends and the dust time to settle down somewhat, to be reckoned with only residual dust.
Grinding the dried pigment is produced in special small mills, the so-called dismembratorah. Mills are in its design fabric bag filter, air from which is emitted into the room. Dedusted this mill is extremely difficult.
The only radical solution - to conclude the mill, together with the filter in an isolated cabin, preferably glazed to which staff comes only periodically, taking care of individual protection, such as a respirator type "petal" of fabric FPP-15.
Installation of a mill in the cockpit is shown in Fig. 38. The amount of air removed from the cabin, made from 1500 to 2000 Martyrs. Since air contains very little dust, it can not be cleaned from it (depending on local conditions). In return, retrieve the cabin air enters the shop through a self-closing bars.