Abstract: A heater includes a convection section with columns and tube sheets coupled to the columns with tubes received in the tube sheets. The convection section includes a space between the tube sheets associated with corresponding pairs of columns. A structural frame is coupled to the columns and positioned in the space to slidably receive one or more catalyst support beds for loading or unloading a catalyst into the convection section through a lateral side of the convection section of the heater. The structural frame may include beams, struts, slide plates, and other frame elements that assist with supporting the catalyst support beds and enable sliding of the catalyst support beds with respect to the structural frame.

Abstract: An electrically heated furnace including one or more unit cells. Each unit cell includes a radiant heating section, one or more process coils disposed within the radiant heating section, and a quench unit for cooling a cracked product from the one or more process coils and producing a quenched reaction product. The furnace also includes one or more electrical heating elements disposed within the radiant heating section, the one or more electrical heating elements are arranged to provide radiant energy to the one or more process coils. Further, the electrically heated furnace includes a first area corresponding to a heating area of the one or more electrical heating elements, a second area corresponding to a wall area of the wall on which the one or more electrical heating elements are disposed, and a third area corresponding to a surface area of the one or more process coils.