Nippon Mining Co., Ltd.

Hitachi, Ltd.

Toyama Prefecture

Soar Corporation

Norihiro Kiuchi

Tomohiko Miyamoto

Susumu Yoshioka

Jinichi Tomuro

Chikara Tominaga

Seiichi Uchida

Yoshihito Satomi

Takeo Yamagata

Hideo Segawa

Katsumi Tanino

Eiji Itoh

Kiyoshi Ogino

Masaru Sakamoto

Masataka Yahagi

Kenji Murakami

Isao Tazawa

An electronic hygrometer and an electronic thermohygrometer both comprising oscillation means and digital operation processing means. The oscillation means of the hygrometer includes a square-wave pulse signal generator, a humidity sensor connected to the generator and which exhibits characteristics variable with the humidity change of the atmosphere, and a passive element connected to the generator and which forms a time constant circuit with the characteristics of the humidity sensor, the passive element being of a type different from the humidity sensor. The oscillation means produces square-wave pulse signals corresponding to changes in the characteristics of the sensor. The digital operation processing means of the hygrometer counts the frequency of the square-wave pulse signals output from the oscillation means and determines the humidity of the atmosphere on the basis of the counted value. The thermohygrometer further comprises a reference resistance element connected in parallel with the humidity sensor, a temperature sensor connected in parallel with the humidity sensor and the resistance element and which exhibits electric resistance variable with the temperature change of the atmosphere, and switching means which open and close the circuits of the humidity sensor, resistance element, and temperature sensor.

Electronic thermohygrometer with square-wave pulse signal generator

A process for fabricating a humidity-sensing element comprises forming an electrode layer on at least one side of a ceramic substrate, applying to the electrode layer a humidity-sensitive paste containing a zirconia, zirconia-yttria, or yttria ceramic as a humidity-sensitive material, drying the coat, and then firing it at a temperature of 750.degree. to 870.degree. C. to form a humidity-sensing part.

Humidity-sensing element

In a reactor for cracking heavy hydrocarbon oil through a fluidized bed of the particles of natural ores, coke-like materials are deposited on a top of the reactor or pipe inside surfaces of a transfer line from the reactor to a scrubber. To effectively scour out the deposited coke-like materials, particles of natural ores having a mean diameter of a few hundred .mu.m is made to be contained in an effluent gas from the top of reactor, passing through the transfer line at a concentration of 1 to 40 g/m.sup.3. The particles of natural ores have a good effect of scouring out the deposited coke-like materials and can keep the transfer line efficiently clean even with a small amount of the particles of natural ores, decreasing a pressure drop in the transfer line.

Apparatus for preventing coking in fluidized bed reactor for cracking

In a reactor for cracking heavy hydrocarbon oil through a fluidized bed of particles of natural ores, coke-like materials are deposited on a top of the reactor or pipe inside surfaces of a transfer line from the reactor to a scrubber. To effectively scour out the deposited coke-like materials, particles of natural ores having a mean diameter of a few hundred .mu.m is made to be contained in an effluent gas from the top of reactor, passing through the transfer line at a concentration of 1 to 40 g/m.sup.3. The particles of natural ores have a good effect of scouring out the deposited coke-like materials and can keep the transfer line efficiently clean even with a small amount of the particles of natural ores, decreasing a pressure drop in the transfer line.

Method for preventing coking in fluidized bed reactor for cracking heavy

Growing community of inventors

Hachioji, Japan

Norihiro Kiuchi