A novel coil-shaped rotating spiral gas-solid contacting device was proposed. The spiral can be made by welding “long-elbows”, which are available as parts of boiler tubes. In the bottom of the spiral, particles form bed, through which whole gas flows without gas bypassing. The bed is transported with the rotation of the spiral. The authors have made transparent cold models and heat-resistant metal models, carried out experimental works, and revealed the properties of this type of reactor for transportation rate of solids, residence time distribution of solids, pressure drop when gas was fed, the maximum limit of gas feed rate to maintain stable bed, gas-solid contact efficiency, heat transfer between wall and solids, and influence of reactor size on above-mentioned properties. This work reveals the influence of scale-up on the maximum limit of gas flow rate at which stable bed is maintained. Gas-solid contact efficiency and heat transfer coefficient were also evaluated using models larger than that used in previous studies. By summarizing the past findings and the present results, a procedure to design a gas-solid catalytic reactor, i.e., determination of tube diameter, rotating rate, number of spiral cycles, and heat transfer rate, is discussed.