Industrial Applications for Inflatable Seals

The Client:

A major steel manufacturer.

The Situation:

The brick duct work that carries off gases from the blast furnace periodically needs cleaning and repair on the inside brick surface of the ducts. Application requirements: When the blast furnace is shut down the brick inside the ducts can be cleaned and repaired. However, there is the concern about residual gases in the system coming from the furnaces, which present a potential health hazard for the repair crew. The ducts vary in size from 10-foot in diameter to 13-foot in diameter. The entryways into the duct system are 24-inch access hatches. The challenge is to seal off the ducts upstream from where the crew needs to make repairs/clean the ducts, and be able to get the sealing device through the 24-inch hatch opening.

The Approach:

Sealing off a 10-foot diameter and a 13-foot diameter would require two different inflatable units. Getting the device through a 24-inch access hatch would mean the device would need to "fold up" small enough to pass through the entry (with the aid of pulling a vacuum on the inflatable).

The Solution:

Manufacture an inflatable torus for each of the diameters in question that had a 30-inch cross section chamber diameter. Attach rings to permit the torus to be suspended by ropes in an un-inflated closed "parachute" configuration.

This permits the inflatable to be lowered into position through the 24-inch hatch. Attach a rubber-coated fabric panel across the torus to act as a barrier when the torus is in place.

The final product was built using lightweight, neoprene-coated nylon fabric. Once inserted into the duct and positioned the torus was inflated with an ordinary shop vacuum unit and topped off with an auxiliary airline.

Sealing pressure for the device is less than 2 psi, and the unit weighed less than 90 pounds.

The Results:

The inflatable torus sealing device successfully deployed and sealed providing a functional work environment for the crew to make repairs and clean the brick ducts. Sometimes in order to provide a solution to an application the designers and engineers think "outside the box!" And, tap into Seal Master's custom-designed, engineered rubber products expertise.