Foundry Baghouse Replaced in Two Weeks, Filter Area Increased 88% While Staying in Same Footprint at Indianapolis Casting Facility

With its Indianapolis diesel engine plant running at full capacity for more than two years, one of the nation's largets automotive suppliers demanded matching speed from Kirk & Blum in replacing a 20-year-old foundry baghouse at its Indianapolis casting facility. The facility casts blocks and heads for the engine plant, adjacent to it on the Indianapolis site, as well as for other customers.

The old dust collector at the foundry had to be torn out and the new baghouse installed, including all new controls, over a two-week vacation shutdown. "We shut down 6 a.m. Saturday, July 1 and needed to be back up and running by midnight, July 16," said the manager of facilities engineering at the plant.

The time squeeze was compounded by one of space. Additional baghouse capacity was needed, but was restricted by other structures at the site to staying within the same footprint.

Kirk & Blum answered with:

Creative bag packaging, redesigning the collectors with tube sheets on staggered centers to enable fitting of more bags into the same area.

Precision pre-fab and modularization of major components creating eight "packages" in the shop, the largest that could be trucked, then joining them on-site into just four units for lifting into place by crane.

Tear-out took half the time scheduled, all major rigging work was completed by the end of the first week, and the new baghouse was on-line, ready to go, at the end of shutdown. The new baghouse increases cloth filter area by 88%, is structurally stronger, improves operator control and automation, and provides greater maintenance accessibility.

High Pressure Project

Founded in 1907, Kirk & Blum specializes in engineering, fabrication, installation and repair of dust and fume control systems, and all types of process ventilation systems. It has extensive experience with automotive plants and the foundry industry. Six Kirk & Blum facilities in the midwest and southeast U.S. enable fast response and close coordination on projects.

K&B's Indianapolis plant performs many projects for the large automotive supplier, with major repairs and up-grades scheduled during summer shutdown. "However, the baghouse replacement eclipsed any previous shutdown project in magnitude and scope," stressed Tim Schneider, Kirk & Blum Vice President and head of the Indianapolis facility. "This was a high profile, high pressure job. Without the baghouse being in operation, the foundry can't run the molding line." Any delay on start-up of the foundry mold line could have had a domino effect, delaying production on engines, then on all vehicles to receive the engines.

"We had to compress what would typically be a six-week installation project for a greenfield site into two weeks with no margin for delays or fixes," said Mike Richardson, K&B Project Manager. "It was a race against the clock. Everything had to be done on time and done right."

Creative Packaging

Prevented by other plant structures from building outward to expand baghouse capacity, Kirk & Blum looked inward and upward.

Designed the collectors with tube sheets having staggered centers to enable fitting more bags into each bag compartment. Plus:

Increased bag length from 7-1/2 ft. to 10 ft.

Increased module size by unitizing three compartments with common wall sections, so all available space was utilized.

The new baghouse has 12 compartments, each with 248 bags. Bags are 6-1/4" diameter x 10 ft long. The creative packaging enables a total of 48,695 sq. ft. of cloth compared to 25,918 sq. ft. previously. At the existing system volume of 174,000 CFM, the air-to-cloth ration has been reduced from 6.7:1 to 3.6:1.

"We needed more cloth capacity," according to the client's facilities engineering department, "The bags tended to load up and bind, so they couldn't clean properly. System efficiency and air flow were compromised." Decreasing the air-to-cloth ratio eliminated the load-up problem. There is less pressure drop, so the baghouse draws more air without increasing fan speed.

Easy to Run and Maintain

Before the replacement, capacity demands and system design required that the full baghouse be constantly on-line, limiting maintenance attention mostly to shutdowns. Consequently, ease of maintenance was given the highest priority in all design consideration. "The bag house redesign now allows any of the 12 bag compartments to be isolated and taken off line at any time for maintenance," the client notes. "The up-grade provides capacity reserve, so there is no problem in taking one of the units off line."

Each compartment is fitted with its own inlet and automatic outlet dampers, plus access door, enabling isolation for maintenance or cleaning. Each compartment is fitted with a compressed air header and 16 pulse valves for automatic cleaning cycles.

The baghouse redesign greatly improved space utilization and accessibility. K&B enclosed the entire baghouse complex, complete with doors at each end and each compartment, allowing maintenance access to all levels, including the roof. Retractable stairs enable access to the clean air plenums. The enclosure now provides space for inside storage of replacement baghouse components. New lighting assures good visibility and work lighting in enclosed areas.

70's to 90's Controls

Controls were totally replaced. "We pretty much went from 70's to 90's technology," said the client. "It gives us more options, more precise control."

The installation included two new Motor Control Centers (MCC). These house all of the motor starters, transformers, controls, programmable logic controller (PLC), and the operator interface. A new distribution panel with circuit breakers provides all control power.

The operator interface/computer gives ICC an automated system with more flexibility and control of the baghouse operation. The operator interface displays the baghouse operations on graphics screens which show the status of the equipment, such as the amperage of the four 150 hp fan motors, pressure differentials, and damper positions. This information is constantly updated and shown on the screens.

The operator interface is connected to the PLC which is used to send signals to the control devices in the system. The PLC also receives signals from remote mounted devices which give indications about the system operation. The PLC uses this information to initiate programmed operations (such as start a cleaning cycle) or sound an alarm if there is a problem. The PLC program can be easily revised to accommodate parameter changes and additional equipment that may be installed in the future.

Precision Pre-Fab

""The key for Kirk & Blum in successfully completing the field work in the two-week time frame was doing as much fabrication and assembly as possible ahead of time," stressed Doug Harris, Field Superintendent.

K&B divided the structure into eight sections, each as big as could be transported to the site by truck. Three baghouse compartments were utilized as single components with common walls, consolidating the 12 baghouse compartments into four units. A matching clean air plenum was created for each 3-compartment baghouse unit. On site, each baghouse unit was joined with its clean air plenum. This left four main "picks" by a crane about 32,000 lbs. each to erect the entire baghouse complex. A 125-ton crane was utilized for the lifts.

"Fabrication of the modules required custom-fitting," said Harris. The rebuild retained existing hoppers, on which the new modules were mounted. Structural steel supports had to be reinforced to accept the additional loads. Existing manifolds were also retained. These were removed during tear-out, then reinstalled with an additional spool piece. "So, everything had to be field measured and fabricated very accurately to fit the existing structure," he noted.

"The client had specified 10 gauge steel for a baghouse with a 3/26" thick tubesheet, which we upgraded to 3/16" and 1/4" plate respectively," said Harris. "Our special expertise and facilities for plate work let us provide the heavier construction and real dollar value with little increase in initial costs."

"Well Planned and Executed", Said the Client

"K&B received the full go-ahead from the clienton the project Apr. 1, only three months from the start of shutdown. Preliminary engineering and field measurements had been completed in order to make a bid proposal but the schedule still left only 10 weeks to do the shop fabrication," noted Mike Richardson, K&B project manager. "The shop worked two shifts the whole time to complete the modules on schedule."

The fabrication phase reinforced the client's confidence that it had made the right decision. "The fab work settled any concerns we may have had about being able to complete the project on schedule," said the client. "Everything was extremely well planned and executed. You could see it coming together like clockwork."

Actually, Doug Harris, K&B field superintendent, admits to one mistake in planning he allowed three days for tear-out of the old system, which actually took only a day-and-a-half. The savings proved crucial, as late on the final week before shutdown, as the customer needed additional production and decided to run an extra day.

Field Phase

Kirk & Blum put together an installation team "second to none" for the field phase of the project, according to Mike Richardson, K&B project manager.

K&B used a 12-man rigging crew for each shift and worked two 10 hour shifts for the first 11 days of the shutdown. Among other things, they did more than 3/4 of a mile of field welding in less than a week.

K&B's electrical subcontractor, had a crew of 7 or 8 people per shift during the second week of installation. They completed all required tearout, installation and testing of the new control system.

A crew of five pipefitters installed the compressed air piping used to clean the filter bags.

An insulating crew was hired to spray polyurethane insulation on the interior of the baghouse to prevent condensation. The main internal sections of bag compartments, clean air and dirty air plenums were insulated before being lifted into position. Later, after the units had been welded together, the foam crew returned to insulate the seams. When the insulating work was completed, a separate crew applied fire retardant material to the entire baghouse interior.

Two cranes and operators handled lift requirements a 125 ton unit for the main picks, while a smaller crane lifted roofing, interior floors and smaller, miscellaneous components and equipment.

"We had a lot of people crawling around in a small, confined area," said Richardson. "Our biggest problem was staying out of each other's way."

Team Project

"This was a great team effort," stressed Schneider, K&B VP in charge of the Indianapolis plant. "The guys in the field really came through with the pressure on and the clock ticking. but, they needed the guys in the shop to do their job right. When everything fits it makes things so much easier in the field."

Did he ever have doubts about finishing the baghouse job on schedule? "I better not have," said Schneider. "We scheduled the crew to go straight to another two-week shutdown project at another foundry."