Abstract: A controller is configured to determine a current gear ratio step determined on the basis of gear ratio calculation Rg to be actual gear ratio of revolution Nm of main shaft 3a and revolution Nc of counter shaft 3b as well as gear ratio map for defining gear ratio variable allowance range for each of gear ratio steps. When making a decision of status of the determined current gear ratio step, the controller is configured to make delay timer get started when the gear ratio calculation Rg goes within the gear ratio variable allowance range of next step and halt to make a decision of the current gear ratio step while the delay timer is activated. The controller is also configured to make a decision of the status of the current gear ratio step after a predetermined delayed time Tn*(n=1, 2, . . . ) is elapsed.

Abstract: A controller is configured to determine a current gear ratio step determined on the basis of gear ratio calculation Rg to be actual gear ratio of revolution Nm of main shaft 3a and revolution Nc of counter shaft 3b as well as gear ratio map for defining gear ratio variable allowance range for each of gear ratio steps. When making a decision of status of the determined current gear ratio step, the controller is configured to make delay timer get started when the gear ratio calculation Rg goes within the gear ratio variable allowance range of next step and halt to make a decision of the current gear ratio step while the delay timer is activated. The controller is also configured to make a decision of the status of the current gear ratio step after a predetermined delayed time Tn*(n=1,2, . . . ) is elapsed.

Abstract: The operation of a plant for producing a gas hydrate is stabilized by making the gas phase within a downstream step have the same equilibrium composition as that of the gas phase within a generation step. The gas phase within a mixed-gas hydrate generation step is circulated to the gas phase within a downstream step located downstream of the mixed-gas hydrate generation step, and the gas phase within each step is thereby made to have the same equilibrium composition as that of the gas phase within the generation step.

Abstract: Provided is a process and an apparatus for producing at low cost gas hydrate pellets having an excellent storability. A gas hydrate generated from a raw-material gas and raw-material water is dewatered and simultaneously molded into pellets with compression-molding means under conditions suitable for generating the gas hydrate while the gas hydrate is generated from the raw-material gas and the raw-material water that exist among particles of the gas hydrate.

Abstract: An improved probe card maintenance method is capable of accurately, rapidly, and easily performing the maintenance of a probe card. The probe card is a jig adapted to test the electrical properties of semiconductor integrated circuits. The electrical properties of the semiconductor integrated circuits are tested at a predetermined test temperature. The probe card has a plurality of probes thereon. The probe card maintenance method includes heating the probe card and the probes on the probe card to the same temperature as the test temperature. The method also includes adjusting positions and postures of the defective probes while maintaining the temperature of the probe card and the probes at the test temperature.

Abstract: A test apparatus for testing semiconductor integrated circuits includes a test head, a probe card holder for detachably holding a probe card that probes a semiconductor device, a heater for heating the probe card, and a heater holder that holds the heater in direct contact with the probe card when the probe card is held by the probe card holder. The test apparatus heats the probe card efficiently and thereby reduces test time and cost.

Abstract: A gas hydrate production apparatus capable of reacting a raw gas with a raw water to thereby form a slurry gas hydrate and capable of removing water from the slurry gas hydrate by means of a gravitational dewatering unit. The gravitational dewatering unit is one including a cylindrical first tower body; a cylindrical dewatering part disposed on top of the first tower body; a water receiving part disposed outside the dewatering part; and a cylindrical second tower body disposed on top of the dewatering part, wherein the cross-sectional area of the second tower body is continuously or intermittently increased upward from the bottom.

Abstract: A gas hydrate slurry dewatering apparatus adapted to feed a raw as into a cylindrical main body of dewatering column so gas to attain pressuriation and so suction any gas from the interior of a drainage chamber disposed around the cylindrical main body so as to attain depressurization. An internal tube (8) as a constituent of a dewatering apparatus (6) in which the gas hydrate slurry (S) is introduced is provided with a separating section (7). A drainage chamber (10) is formed by the internal tube (8) and, disposed with a given spacing therefrom, an external tube (9). An exhaust blower (B2) and a drainage pump (P2) are connected to the drainage chamber (10). A gas feed blower (B3) for a raw gas (G1) is connected to the internal tube (8). A differential pressure detector (x1) is provided for detecting any pressure difference between the interior of the internal tube (8) and the interior of the drainage chamber (10).

Abstract: Provided is a process and an apparatus for producing at low cost gas hydrate pellets having an excellent storability. A gas hydrate generated from a raw-material gas and raw-material water is dewatered and simultaneously molded into pellets with compression-molding means under conditions suitable for generating the gas hydrate while the gas hydrate is generated from the raw-material gas and the raw-material water that exist among particles of the gas hydrate.

Abstract: A gas hydrate production apparatus capable of reacting a raw gas with a raw water to thereby form a slurry gas hydrate and capable of removing water from the slurry gas hydrate by means of a gravitational dewatering unit. The gravitational dewatering unit is one including a cylindrical first tower body; a cylindrical dewatering part disposed on top of the first tower body; a water receiving part disposed outside the dewatering part; and a cylindrical second tower body disposed on top of the dewatering part, wherein the cross-sectional area of the second tower body is continuously or intermittently increased upward from the bottom.

Abstract: Provided is a process and an apparatus for producing at low cost gas hydrate pellets having an excellent storability. A gas hydrate generated from a raw-material gas and raw-material water is dewatered and simultaneously molded into pellets with compression-molding means under conditions suitable for generating the gas hydrate while the gas hydrate is generated from the raw-material gas and the raw-material water that exist among particles of the gas hydrate.

Abstract: The operation of a plant for producing a gas hydrate is stabilized by making the gas phase within a downstream step have the same equilibrium composition as that of the gas phase within a generation step. The gas phase within a mixed-gas hydrate generation step is circulated to the gas phase within a downstream step located downstream of the mixed-gas hydrate generation step, and the gas phase within each step is thereby made to have the same equilibrium composition as that of the gas phase within the generation step.

Abstract: A gas hydrate production apparatus capable of reacting a raw gas with a raw water to thereby form a slurry gas hydrate and capable of removing water from the slurry gas hydrate by means of a gravitational dewatering unit. The gravitational dewatering unit is one including a cylindrical first tower body; a cylindrical dewatering part disposed on top of the first tower body; a water receiving part disposed outside the dewatering part; and a cylindrical second tower body disposed on top of the dewatering part, wherein the cross-sectional area of the second tower body is continuously or intermittently increased upward from the bottom.

Abstract: Disclosed is a process for production of a gas hydrate, wherein the process comprises a gas hydrate production step, a cooling step, a depressurizing step and a re-cooling step. In the cooling step, the temperature (T) required for the cooling of the gas hydrate is adjusted to a temperature equal to or higher than a cooling limit temperature (t1+t2) (which is a sum of an equilibrium temperature (t1) of the gas hydrate and a temperature for correction (t2)) and equal to or lower than the freezing point (0° C.).

Abstract: The composition of raw mixed gas and the gas composition of produced mixed gas hydrate are uniformed as rapidly as possible. The process for producing a mixed gas hydrate comprises the gas hydrate forming step of reacting a mixed gas (g) with water (w) to thereby obtain a gas hydrate in slurry form; the dewatering step of removing the water (w) from the gas hydrate slurry (s); the palletizing step of forming the gas hydrate after water removal into pellets; the freezing step of chilling the gas hydrate pellets (p) to the freezing point or below to thereby freeze the same; and the pressure reduction step of depressurizing the frozen gas hydrate to storage pressure, wherein the mixed gas (g) fed to the gas hydrate forming step is diluted by diluent gas (m) as a constituent of the principal components of the mixed gas (g).

Abstract: A gas hydrate production apparatus capable of reacting a raw gas with a raw water to thereby form a slurry gas hydrate and capable of removing water from the slurry gas hydrate by means of a gravitational dewatering unit. This gravitational dewatering unit is one including a cylindrical first tower body; a cylindrical dewatering part disposed on top of the first tower body; a water receiving part disposed outside the dewatering part; and a cylindrical second tower body disposed on top of the dewatering part, wherein the cross-sectional area of the second tower body is continuously or intermittently increased upward from the bottom.

Abstract: A gas hydrate production apparatus capable of reacting a raw gas with a raw water to thereby form a slurry gas hydrate and capable of removing water from the slurry gas hydrate by means of a gravitational dewatering unit. The gravitational dewatering unit is one including a cylindrical first tower body; a cylindrical dewatering part disposed on top of the first tower body; a water receiving part disposed outside the dewatering part; and a cylindrical second tower body disposed on top of the dewatering part, wherein the cross-sectional area of the second tower body is continuously or intermittently increased upward from the bottom.

Abstract: A process for producing gas hydrate pellets includes generating a gas hydrate by reacting raw gas and raw water under predetermined temperature and pressure conditions, and then shaping the gas hydrate into pellets by means of a pelletizer. Newly-formed gas hydrate or still-moist gas hydrate that has been partially dehydrated is shaped into pellets by means of a pelletizer, the shaping being conducted under conditions of the gas hydrate formation temperature and formation pressure. Subsequently, the shaped pellets are cooled to a sub-zero temperature by means of a refrigerating machine.

Abstract: The composition of raw mixed gas and the gas composition of produced mixed gas hydrate are uniformed as rapidly as possible. The process for producing a mixed gas hydrate comprises the gas hydrate forming step of reacting a mixed gas (g) with water (w) to thereby obtain a gas hydrate in slurry form; the dewatering step of removing the water (w) from the gas hydrate slurry (s); the palletizing step of forming the gas hydrate after water removal into pellets; the freezing step of chilling the gas hydrate pellets (p) to the freezing point or below to thereby freeze the same; and the pressure reduction step of depressurizing the frozen gas hydrate to storage pressure, wherein the mixed gas (g) fed to the gas hydrate forming step is diluted by diluent gas (m) as a constituent of the principal components of the mixed gas (g).

Abstract: Provided is a process and an apparatus for producing at low cost gas hydrate pellets having an excellent storability. A gas hydrate generated from a raw-material gas and raw-material water is dewatered and simultaneously molded into pellets with compression-molding means under conditions suitable for generating the gas hydrate while the gas hydrate is generated from the raw-material gas and the raw-material water that exist among particles of the gas hydrate.