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How Tectoniks’ Dreamforce, an air-inflatable structure that is one and a half football fields in length, keep its figure during the world’s largest vendor-sponsored trade show.
The world’s largest vendor-sponsored trade show, Dreamforce 2013, brought downtown San Francisco to a standstill last November when it hosted more than 130,000 cloud computing enthusiasts from 65 countries.
The event, hosted by Salesforce.com, was staged at the Moscone Conference Center and much of the surrounding area, including Howard Street, which was closed to traffic for the duration of the four-day event.
Tectoniks supplied a huge inflatable structure that covered Howard Street in San Francisco for four days and nights.
Inflation Systems
Each inflatable module has two independent inflation systems that are housed inside the custom made concrete shoes. One system provides high-pressure air for the tubular framework, the other provides low-pressure air for the pillows.
Each system is made up of two compact side-channel blowers that deliver air via non-return valves to a rigid PVC pipework manifold. The manifold is connected to the inflatable structure via a 2-inch bore flexible hose and bayonet style valve. The valves, pipework and hoses are all concealed within the concrete shoes.
Each manifold provides a connection to a 2-inch bore electric pressure relief valve. The blowers and relief valve in each system are controlled by electronics housed inside an enclosure, which is also located in the inflation system compartment concealed within the concrete shoes. Pressure transducers continually sense the air pressure in the tubular framework and pillows. This information is then fed to digital process controllers that operate the blowers and relief valves as required to maintain the correct operating pressures.
Air distribution
Each module is comprised of two distinct inflatable elements that operate at different pressures (the high-pressure framework and low-pressure pillows).
A major challenge was devising a solution to deliver air to these two different elements and to maintain the correct operating pressure in each. In order to preserve the aesthetics of the structure, the air distribution system had to be concealed from view.
Inflating the high-pressure framework was straightforward. The base of one corner of the structure was fitted with a bayonet valve to which the 2-inch bore flexible inflation hose was connected. This hose then ran to the inflation system concealed within a concrete shoe. The valve and hose were also entirely concealed within the shoe.
A second, small-bore (4 mm) tube is connected between the base of the inflatable and a pressure transducer, which is part of the electronic pressure control system. This tube allows the system to sense the air pressure inside the structure.
Inflating and maintaining pressure in the pillows involved connecting the inflation hose running from the inflation equipment to a bulkhead fitting on the base of the inflatable framework. This fitting allows the hose to effectively pass through the wall of the inflatable and to continue inside. The hose then runs up the inside of the inflatable framework before passing through another bulkhead fitting and into the pillow located at the top center of the module.
Each pillow is connected to adjacent pillows using an internal network of bulkhead fittings and 1-inch bore flexible hose (see diagram ‘pillow air connection.jpg’).
Using this method, air is delivered from the inflation equipment to the top center pillow. The air then feeds out into adjacent pillows via the internal network of hoses.
The final part of the solution involves running a small-bore (4 mm) flexible tube from the top pillow down through the inside of the tubular framework to the pressure transducer housed inside the enclosure for the inflation system electronics. This tube allows the air pressure in the pillows to be sensed by the electronics, which control the inflation equipment.