Abstract: There is here disclosed an apparatus for continuously measuring on an on-line system a flash point of an intermediate fraction such as kerosene in a petroleum distillation process from a difference between gas concentrations of the intermediate fraction at two predetermined temperatures; and a method for controlling the flash point of the intermediate fraction from the thus measured value.

Abstract: Disclosed are a heat exchange element obtained by forming a sheet material or honeycomb structure having a shape required for a heat exchange element from an organic filler-filled sheet made from an acid-resistant glass fiber, dipping the formed sheet material or honeycomb structure in a suspension of an inorganic filler, at least a part of which is composed of scaly particles, and fixing the inorganic filler applied by the dipping treatment to the sheet material or honeycomb structure by a binder, and a process for the preparation of this heat exchange element and a heat exchange apparatus comprising this heat exchange element. A high acid resistance and a high gas-intercepting property can be maintained even by using a thin and light sheet material.

Abstract: A heat transfer element for cross flow heat exchanger consists of ceramic corrugated and planar plates. A plurality of the heat transfer elements are stacked up in such a manner that the direction of corrugation in adjacent elements intersects at right angles to form a heat transfer block for cross flow heat exchanger. Concave portions of corrugation, which confront soot-blowing flow for removing soot deposited onto the heat transfer surfaces of heat transfer block, are filled with ceramic solids. Also concave portions of corrugation corresponding to the corners, which abut the packings attached when the heat transfer block is installed on a casing, are filled with ceramic solids.