Design Characteristics:

• Provide capture velocities at openings of 350-500 FPM
• Duct velocity - 3,500

Application Tips:

• Provide drains in ductwork
• All air moving/handling equipment to be sulfuric acid resistant

Design Characteristics:

• Enclosure to provide capture velocities at opening of 350-500 FPM
• Transport velocity in ducts greater than or equal to 4000 FPM

Design Characteristics

• Transport velocity in ducts: > 4000 fpm
• Enclosure to provide capture velocities at opening of 350-500 fpm

From American Conference of Governmental Industrial Hygienists (ACGIH®), Date: 1-91, Figure VS-50-10, Industrial Ventilation : A Manual of Recommended Practice, 23rd Edition. Copyright 1998. Reprinted with permission.

Notes

• Locate exhaust outside
• Overdesign for lead transport
• Provide ample hose and attachments at each access point
• Provide access point close to areas of high dust concentration

Design Characteristics

• Check with supplier.

Application Tips

• Install at entrance to clean-rooms, lunchroom, etc.
• Allow time for full use by employees.
• Provide daily cleaning and maintenance.

Volumtric flow rate:

Mold filling hood (T1) - 1650 cfm

Launder hood (T2) - 2460 cfm

Metal tapping hood (T3) - 3660 cfm

Proceedings of the Symposium on Occupational Health Hazard Control Technology in the Foundry and Secondary Non-Ferrous Smelting Industries, U.S. Department of Health and Human Services, NIOSH Publication No. 81-114 (1981).

From American Conference of Governmental Industrial Hygienists (ACGIH®), Date: 1-91, Figure VS-50-20, Industrial Ventilation : A Manual of Recommended Practice, 23rd Edition. Copyright 1998. Reprinted with permission.
 

Design Characteristics

• Enclosure to provide capture velocities at openings of 350 - 500 FPM
• Transport velocities in ducts: ≥ 4000 FPM

Application Tips

• Locate inlet in lead free area
• Temper inlet aid - provide thermostat at work station
• Provide outlet nozzle as close to breathing zone as possible

Design Characteristics

• Q = 100 scfm/sq ft of cab cross-sectional
• v face = 100 fpm at breathing zone
• sp reg = typically 5-6" w.g.

Application Tips

• Distribute air evenly across cab cross-section.
• Provide temperature controls at operators station.
• Provide for rapid filter change.

NIOSH articles:

• Improved Cab Air Inlet Location Reduces Dust Levels and Air Filter Loading Rates
• Floor Heaters Can Increase Operator's Dust Exposure in Enclosed Cabs
• Sweeping Compound Application Reduces Dust From Soiled Floors Within Enclosed Operator Cabs

Design Characteristics

• Transport velocity in ducts: > 4000 fpm
• Enclosure to provide capture velocities at opening of 350-500 fpm

Q= 25 - 60 cfm/inch diam. or width
Bronch static pressure = 7 to 14 "Hg
Slot velocity = 30,000 to 39,000 fpm
Flexible hose = 1" to 2" ID
Extension hose = Up to 8 ft long^*
Peripheral speed = 6,000 tp 12,000 inear fpm

^*Hose lengths may be extended up to a maximum of 50 ft by using larger sizes between the tool hose and the tubing system.

From American Conference of Governmental Industrial Hygienists (ACGIH®), Date: 10-90, Figure VS-40-02, Industrial Ventilation : A Manual of Recommended Practice, 23rd Edition. Copyright 1998. Reprinted with permission.

Facility Function/Description

1. The facility can be entered from the street at only one point. (A)
2. Street clothes are removed and clean work clothes, hardhat, and respirator are issued and donned in the street side locker room. (B)
3. The employee passes through a one-way turnstile in order to get to the plant-side locker room. (C)
4. The employee dons work boots and other safety gear in the plant-side locker room where they are stored. (D)
5. There is only one entry to the plant. (E)
6. The restroom just inside the cloak room is readily accessible during working hours. (F)
7. The cloak room provides a place to store coats, hardhats, gloves and respirators during break periods. (G)
8. During lunch break the employee first cleans his boots at the shoe cleaning machines (H), leaves coat and equipment in the cloak room (G), vacuums off his clothes at the vacuum stations (I), proceeds to the hand washing station where he thoroughly washes his hands (J), and finally enters the lunch room. (K)
9. At the end of the shift the procedure is as follows: the employee cleans shoes (H), removes contaminated clothing in the plant side locker room (D), stores boots, etc. in plant-side lockers, turns in dirty work clothes, hardhat and respirator to laundry (L), and proceeds to the showers. (M)  He then must pass through an automatic shower (N) to return to the street-side locker room (B), where he dresses and leaves the faculty. (A) 

Design Criteria

Casting Hood:   Q = 500 scfm/sq ft of equipment + 100 scfm/sq openings

  h_c = .5 VP_duct

  V_transport ≥ 400 fpm

Cooling Hood:

  Q = 100 scfm/sq ft openings + 500 scfm per gal H₂₀ used per minute

  h_c = 3.3 VP

Volumetric flow rate:

(T1) Mold filling hood - 1650 cfm

(T2) Launder hood - 2460 cfm

(T3) Metal tapping hood - 3660 cfm

(T5, T6, T7, T8) Refining kettle hoods -  4700 cfm

(T9, T10) Skip hoist furnace charging hood - 12100 cfm

(T12) Slag tapping hood - 4540 cfm

(T14) Skip hoist hoods (top and bottom) - 3930 cfm

(T15) Slot hood over furnace access doors - 1940 cfm

Exhaust pickups for new kettle hoods - 2940 cfm

Discharge from slag tapping baghouse - 5000 cfm

Inlet to main exhaust fan for smelter exhaust ventilation system

- 41700 cfm

From American Conference of Governmental Industrial Hygienists (ACGIH®), Figure VS-65-01, Industrial Ventilation : A Manual of Recommended Practice, 23rd Edition. Copyright 1988. Reprinted with permission.

Design Criteria:

• SP is greater than or equal to 72" W.G. (inlet)
• Q = 40 CFM
• Use steel mold
• Source must be within 1" of hood

Design Characteristics:

• Volume flow rate of kettle surface area
• Dust Velocity greater than or equal to 4000 FPM

Construction Notes

• Enclose to provide at least 250 FPH face velocity at all openings
• Provide adequate lifting points for hood assembly associated ductwork

W = 0.25' (Typical)

V_SLOT = 2000 fpm

Q = 2000 · W · L

h _e = 1.78 VP_SLOT + 0.25 VP_SLOT

Applications Tips:

• Thoroughly characterize fugitive emissions prior to design
• Provide Make-up air
• Avoid the use of man-cooling fans

Design Characteristics:

• Q = (Natural rising velocity at hood face at 100 FPM) times surface area of hood in square feet
• V is greater or equal to 4000 FPM transport (horizontal runs)
• he = 2.2VP

Provide exhaust ventilation, if necessary, to prevent brushes from throwing lead contaminants into operator's breathing zone.

Battery Shredding and Emission Control

Application Tips:

• Provide local exhaust on shredder.
• Provide building exhaust to keep fugitive emissions inside the building.

Design Characteristics:

Q = 350 cfm/sq. ft. hood opening

Design Criteria

• V_slot = 1000 fpm
• Q = 1000 ctm
• V_duct = 4500 fpm
• he = 0.5 VP_duct

From American Conference of Governmental Industrial Hygienists (ACGIH®), Date: 1-91, Figure VS-50-21, Industrial Ventilation : A Manual of Recommended Practice, 23rd Edition. Copyright 1998. Reprinted with permission.

From American Conference of Governmental Industrial Hygienists (ACGIH®), Date: 1-91, Figure VS-50-22, Industrial Ventilation : A Manual of Recommended Practice, 23rd Edition. Copyright 1998. Reprinted with permission.

System Notes
Bell and socket, smooth - flow type
tubing and fittings should be used
throughout the system.
When System is used for vacuum
cleaning of abrasive materials. Schedule
Nol40 pipe and cast iron drainage fittings,
or heavier, should be used in place of tubing.

Design Criteria

• Q = 350 cfm/lineal ft of hood
• Hood length = required working space
• Bench width = 24" maximum
• Duct velocity ≥ 4,500 fpm
• h_esub = 1.78 VP_slot + 0.25 VP_duct