DRY FILTER PAINT BOOTH CONVERSION
Plumbum, Pb; Cr

Revision: 9/96

Process Code: Navy and Marine Corps: ID-05-99; Air Force: PA01; Army: PNT

Usage List: Navy: Medium; Marine Corps: High; Army: High; Air Force: High

Substitute for: Water Curtain Spray Booths

Applicable EPCRA Targeted Constituents: Lead (CAS: 7439-92-1), Chromium (CAS: 7440-47-3), and Zinc Compounds


Overview:

This data sheet covers the conversion of an existing water curtain spray booths to a dry filter system for the removal of paint based particulates from spray booth air emissions.

There are many types of dry filter systems, however, all operate on the same principle: particulate-laden air flowing towards the filter media is forced to change directions rapidly. The particulate, having more inertia than the surrounding air, impacts the filter media and is removed from the air flow. The scrubbed air is vented into the atmosphere.

Before installing this technology, there are several system issues to be considered in the conversion of a paint spray booth. These include characteristics and applicability of dry filter systems, required fan size, dry filter surface area, paint booth duty cycles, and paint usage rates. There are many types of dry filter particulate emissions control systems (PECS) and filters available.

There are four principal types of filters currently used: fiberglass cartridges, multilayer honeycombed paper rolls or pads, accordion-pleated paper sheets, and cloth rolls or pads. Each type of filter has different characteristics for particulate capacity, removal efficiency, cost, and replacement time. Filter performance is characterized by three basic parameters: particulate capacity, resistance to air flow, and particulate removal efficiency. Filter replacement is required when the filter becomes heavily laden with captured particulates, resulting in a reduction in removal efficiency and an increase in the pressure differential across the filter face.

The wastestream generated is a spent filter laden with paint booth particulate emissions. No other media is contaminated during the collection of the particulate waste, hence the quantity of waste generated is minimized. The removal, disposal, and replacement of the spent filters is a simple procedure.

The existing technology employs a water curtain to remove particulate emissions. The primary disadvantage of this technology is the generation of large quantities of wastewater and paint sludge. The wastewater typically requires off-site treatment and the paint sludge is frequently disposed as a hazardous waste.

When using lead or zinc chromate paints, the dry filter will eliminate approximately 50 to 90% of the hazardous waste that is generated by a water curtain spray paint booth.

Materials Compatibility:

Powder paint is typically not used in dry filter paint booths because this type of paint is usually recycled, which is not economical using a dry filter paint booth.

Safety and Health:

The concerns with the dry filter systems are with the variety of paints that are used and the potential contaminant exposure. When using lead and zinc chromate paints, inhalation of lead or zinc can irritate the respiratory tract and can be poisonous. Some lead compounds are carcinogenic. Solvent-based paints can irritate the lungs and mucous membranes. Prolonged exposure can affect respiration and the central nervous system. Proper personal protection equipment (PPE) should be used. These safety and health issues are also a concern with water curtain spray booths.

Consult your local industrial health specialist, your local health and safety personnel, and the appropriate MSDS prior to implementing this technology.

Benefits:

  • Decreased operating costs when compared to water curtain spray booths:
  • Eliminates chemical costs
  • Reduces electrical costs
  • Eliminates water costs and potential sewer disposal costs
  • Reduces waste generation by eliminating wastewater and paint sludge wastes
  • Eliminates need for daily skimming and removal of sludge from the booth
  • Increased particulate removal efficiency

Disadvantages:

  • Not compatible with powder paint applications
  • Filter selection is dependent on paint type and application
  • Frequent downtime periods are likely due to improper filter selection.

Economic Analysis:

Converting a water curtain spray booth to a dry filter paint booth can be easily accomplished and can be done in-house. The cost of conversion usually ranges from $200 to $2,000, depending on the size and condition of the old water curtain spray booth. Purchasing a new dry filter paint booth can cost between $2,000 and $20,000. The conversion from a water curtain spray booth to a dry filter paint booth can save several thousand dollars in operating and maintenance costs per year.

Assumptions (from Columbus Industries, Inc.):

  • Water curtain spray booth is 7' high, 12' wide; dry filter booth has 28 modules, each 20"x 20"
  • Eight-hour shift, five days per week
  • Electricity cost: $0.055/kwh
  • Power requirements: water curtain system uses 15 hp motor, dry filter uses three hp motor
  • Chemical requirements for water curtain system: 20 lbs/shift
  • Chemical cost: $0.80/lb
  • Filters usage rate: 10/shift
  • Filter cost: $0.62/filter
  • Wastewater generated: 1,000 gallons/shift
  • Wastewater sludge generated: 20 lbs/shift
  • Labor requirements: water curtain requires 12 min./shift, dry filter requires 10 min./shift
  • Labor rate: $45/hr
  • Dry filter disposal cost: $1/filter
  • Wastewater disposal cost: $8.24/1,000 gallons
  • Wastewater sludge disposal cost: $2/lb

Annual Operating Cost Comparison for
Dry Filter Paint Booth Conversion and Water Curtain Spray Booth

Dry Filter Water Curtain
Operational Costs:
Labor: $2,000 $2,300
Material $1,600 $4,200
Energy $260 $1,300
Waste Disposal $2,600 $12,500
Total Costs: $6,500 $20,300
Total Income: $0 $0
Annual Benefit: -$6,500 -$20,300

Economic Analysis Summary

  • Annual Savings for Dry Filter System: $13,800
  • Capital Cost for Diversion Equipment/Process: $2,000
  • Payback Period for Investment in Equipment/Process: < 1 year

Approving Authority:

Navy: Approval is controlled locally and should be implemented only after engineering approval has been granted. Major claimant approval is not required.

Points of Contact:

Charles Tittle
NAVSEA 00TB
Naval Sea Systems Command
2531 Jefferson Davis Hwy.
Arlington, VA 22242-5160
Phone: (703) 602-3594
DSN: 332-3594
Fax: (703) 602-7213

Bob Fredrickson
Naval Facilities Engineering Service Center, ESC423
1100 23rd Avenue
Port Hueneme, CA 93043-4370
Phone: (805) 982-4897
DSN: 551-4897
Fax: (805) 982-4832

Vendors:

The following is a list of Dry Filter Booth manufacturers. This is not meant to be a complete list, as there are other manufacturers of this type of equipment.

Columbus Industries, Inc.
P.O. Box 257
2938 State Route 752
Ashville, OH 43103
(614) 983-2552

The DeVilbiss Company
1724 Indianwood Circle, Suite F,
Maumee, OH 43537-4050
(800) 338-4448

Research Products Corp.
P.O. Box 1467
Madison, WI 53701-1467
(608) 257-8801

Chemco Manufacturing Company, Inc.
3175 MacArthur Blvd.
Northbrook, Illinois
(800) 323-0431

Sources: Columbus Industries, Ashville, OH