A BLAST ROOM WILL SAVE YOU MONEY
Simply switching from expendable to recyclable abrasive used with recovery and abrasive cleaning equipment can produce significant savings. Recyclable abrasives, such as steel grit can be used 200 or more times. An efficient blast facility for small, medium or large workpieces can pay for itself in media savings alone, sometimes in less than one year.
The Safer Choice
Companies who opt to blast rather than chemically-strip reduce employee exposure to dangerous chemicals, often times realizing great cost savings from reduced disposal costs.
Today’s ever-tightening environmental regulations restrict outdoor blasting. Bringing the process inside offers greater operational flexibility—blasting can go on 24/7. No more worries about weather, time of day, or adjacent activities.
COMPONENTS OF AN EFFECTIVE BLAST FACILITY
MEDIA CHOICE DRIVES RECOVERY SYSTEM SELECTION
The recovery system catches and transports spent abrasive for cleaning and reuse. It is the heart of the blast room system and the key to efficiency and returns on investment. Unique methods of recovery suit specific types of blast abrasive. It is therefore critical to determine what blast media will be used before planning the blast room or requesting a quotation.
Clemco systems are classified as mechanical or pneumatic. Mechanical recovery is for heavy abrasives, such as steel grit and other coarse-mesh abrasives. Pneumatic recovery handles lightweight materials, such as plastic, starch, glass bead and aluminum oxide up to size 16 grit.
Often there is confusion when specifying abrasive. Grit is angular with defined edges for cutting peaks and valleys into the blast surface. Shot is round and produces a dimpled surface. To make the most of your investment, use abrasives specifically manufactured for blasting that provides multiple blast cycles.
THE RECOVERY SYSTEM
HEAVY - ABRASIVE RECOVERY
Belt Conveyor The Clemco Belt Conveyor system is simple, reliable, and very low maintenance. The belt system can be configured as a full-area or partial-area recovery system. Spent abrasive falls to the floor and into channels covered by floor grating. Below the grating are recessed hoppers, engineered to meter the abrasive onto the belt. grit.
Flat-Trak® Flat-Trak® is a full area recovery system with minimal pit requirements. The Flat-Trak® recovers abrasive through a series of channels. The channels are fitted with vanes that move forward and backward. On the forward stroke, the abrasive is pushed to the next vane in line
Screw Conveyor Clemco offers Screw recovery systems as an alternative for steel grit applications for those customers who prefer this technology. Screw floors are available in full-area and partial-area sweep-in configurations.
Hopper (Recessed or Wall-Mounted) Normally the least expensive option for small rooms is the hopper system. The 3 x 3 is a mechanical sweep-in system installed in a recessed pit inside the room along a wall. The grating is flush with the floor level. The bucket elevator, abrasive cleaner, and blast machine are located on the other side of the wall outside the room. A wall-mounted 2 x 2 system eliminates the need for a recovery pit.
Lightweight Abrasive Systems / Pneumatic
Critical to high performance is efficiency of the abrasive cleaning system. Separating dust and fines from reusable media affects the cost per media cycle and the life expectancy of the dust collector filters. Too much reusable media carried over to the dust collector wastes media and prematurely wears filter cartridges. Clemco offers two styles of abrasive cleaners. A mechanical abrasive cleaner for heavy media, and pneumatic abrasive cleaner for lighter media.
Mechanical Abrasive Cleaner
The Clemco Air Wash Abrasive Cleaner (AWAC) is a gravity-feed system, used with all mechanical floor recovery, such as the Belt Conveyor, Flat-Trak®, and Hopper Sweep-in systems. A rotating scalping drum culls debris from the media stream. The spent media, dust, and fines cascade over a series of baffles. A high-volume air stream is drawn through the falling media to remove dust and fines. Reusable media is carried either to a storage hopper or it drops directly into the blast machine.
Pneumatic Abrasive Cleaner
The Clemco Media Reclaimer is a cyclone separator used to clean lightweight media, such as glass bead, plastic, starch, and fine aluminum oxide. It is used with our pneumatic M-Section® recovery systems. A high-volume air stream carries media into the cyclone separator where heavier media particles are spun to the outside of the cylinder, while dust and broken media are drawn out with the exhaust air from the center. The reclaimer can be precisely tuned to minimize usable media carryover to the dust collector.
The enclosure contains the blast process. It is sized to allow sufficient space for the maximum work-piece size plus a minimum of four feet on all sides for the operator to work. Enclosures can also be sized to allow multiple operators to work within the enclosure at the same time. Make sure to assess your current and future needs so that your choices today will accommodate your operation for a reasonable period of time in the future
Column-bolt enclosures offer the greatest structural strength using prefabricated bolt-on panels affixed to a structural steel frame. This style is suited to large rooms, wider than 30 feet and/or higher than 20 feet, or for rooms designed for a monorail parts handling system
Reinforced flange-bolt enclosures use the same prefabricated bolt-on panels and offer a combination of added structural strength at a more economical price point. Perfect for enclosures 12 to 30 feet wide, or 12 to 24 feet high.
Flange-bolt enclosures are more economical; they are built with prefabricated panels that bolt together without the support of a frame. Flangebolt construction is suitable for rooms up to 12 feet wide and high. The wall panels typically are fabricated with 10-gauge galvanized steel.
Work-pieces enter the blast room through large, full-opening doors on one or both ends of the room. Two swing-type doors on one end of the room are most common. Doors on both ends of the room allow for work to flow through to the next process, such as painting. Bi-fold doors and rubber roll-up doors are other options. In addition, OSHA requires one personnel door for every 30 feet of room length. A personnel door not only offers an emergency exit but also easy entry/exit for the operator or supervisor.
Depending upon the size, weight, and type of parts to be blasted, customers will choose the most suitable method to move product into and out of the room. Forklifts, rail-mounted work cars, overhead monorails, and other common systems can be integrated into the room. Their integration may impact the design and specifications, so it’s important to consider these handling systems when beginning to plan your blast room.
A control panel serves as the interface between your existing power supply and the blast room equipment. A central control panel dedicated to the blast room and related components is recommended. Standard panels are in NEMA-12 enclosures. Panels rated as explosion-proof or other special specification can be accommodated as requested. Note your requirements on the RFQ form.
The Dust Collector
Dust collection removes airborne dust and particles and maximizes visibility. Reverse-pulse dust collection provides the most efficient solution for blast room dust collectors today. A Clemco CDF Dust Collector with a powerful exhauster motor performs the critical function of ventilating the blast room by drawing air through the room at an adequate velocity. Most applications call for air movement at a rate of 60 feet per minute; while for particularly dusty or hazardous-dust applications, rates as high as 100 feet per minute may be required. Local regulations may affect air-movement requirements. Room size (width and height) and several other factors come into play when determining dust collector size: the condition of the part being blasted, the amount of dust produced by the blast abrasive/media, and any additional ventilation demanded from the media reclaimer. With M-Section® recovery a separate reclaimer is often installed for the most efficient media cleaning. Dust collector operation is simple. Dust from the blast room is ducted to the dust collector where it enters the filter area. The filter cartridges trap the dust on their exterior surface and release it with periodic reverse pulsing of air flowing from the inner circumference of the cartridge. Seasoning of the cartridge prior to initiating the periodic pulse protects the cartridge filters from premature wear and extends the cartridge life. Clemco CDF dust collectors are reverse-pulse style with filtering provided by pleated polyester cellulose filter cartridges of our own design. The cartridges are arranged horizontally for easy access. CDFs provide a nominal 2 to 1 air-to-cloth ratio. CDF collectors feature a sloped roof so that precipitation sheds naturally, as they are often installed outdoors. The collector is most often installed outdoors and should always be located as close to the room as possible to minimize ducting and maximize dust collection efficiency.
BLAST MACHINE SYSTEM
Stationary six-cubic-foot capacity single-operator blast machines are the standard for most rooms. Multiple-operator machines are also available; however single-operator blast machines beneath a storage hopper for refilling offer the simplest set-up, allowing each operator to blast independently. When lightweight media, such as plastic or starch, will be used, an AEROLYTE® blast machine, featuring a steep cone for smooth media flow is recommended. The blast machine package that comes with the room includes remote controls, abrasive metering valve, abrasive cut-off system, coupled blast hose, nozzle, air filter, and personal protective equipment for the blast operator.
Personal Protective Equipment
The Clemco PPE package supplied with most rooms includes a NIOSH-approved Clemco Apollo respirator, air conditioning device, hoses, spare lenses, a breathing-air filter, a heavy-duty blast suit, and a pair of gloves.
Carbon Monoxide Monitoring
To ensure the safety of the blast operator, most facility owners choose to include carbon monoxide (CO) monitoring of the air coming from the compressor. Two options for blast rooms are the CMS-1, a wall-mounted unit, or the CMS-3 personal monitor, which mounts inside the Apollo respirator. The benefit of the CMS-3 is its immediate warning directly to the wearer of the respirator.
COMPRESSED AIR SYSTEM
A CLEMCO REMINDER — WORK IS DONE IN DIRECT PROPORTION TO THE VOLUME OF AIR AND PRESSURE AT THE NOZZLE. HAVING A COMPRESSED AIR SUPPLY OF SUFFICIENT VOLUME AND PRESSURE IS EXTREMELY IMPORTANT.
Compressed air powers the blast machine, the controls, the dust-collector pulse function, the recovery floor (pneumatic systems for lightweight media) and the breathing-air supply. When compressed air is used for both blasting and breathing, it must meet the specifications for Grade-D as defined by the Compressed Gas Association in their commodity specification G-7.1. Most problems associated with blasting can be traced to the compressed air supply. Blasting requires an abundant supply of clean, dry air delivered to the blast machine through a large-diameter hose. Damp abrasive hinders flow through the machine. Too-small a hose cannot supply enough air quickly. The orifice size of the blast nozzle, the size of the recovery floor, the respirator and any breathing air conditioning devices impact compressed air consumption (air volume).
PRE- ASSEMBLED BLAST ROOMS
To speed the purchasing process and minimize installation expense, the Clemco preassembled blast room fills the bill. A preassembled room measures 7 feet wide by 14 feet long by 8 feet high. It arrives ready to be positioned, and for ducting and electrical supply hookups. While it requires no excavation, it may be placed in a pit to minimize entry height. The system includes the enclosure, full-floor recovery, abrasive cleaner, blast machine, PPE, and dust collector. Wall curtains are optional. Two standard models of preassembled rooms are available: one for glass bead, harsh/aggressive media, lightweight media, the other for heavy abrasives.
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