| 摘要 |
<p>PURPOSE:To achieve shortening of the starting time of the liquefied gas pump and the reduction in size of a high-pressure liquefied gas tank, by using a liquid level gauge for confirmation of ending of pre-cooling instead of practising the conventional visual check and also by making it possible to close the switch of the pump automatically so that necessity of manual operation in the field can be eliminated. CONSTITUTION:When liquid level in a high-pressure liquefied nitrogen tank 2 became lower than a certain value, a nitrogen blow valve 8 and a pre-cooling valve 7 are opened through a contact-equipped liquid level guage 13. Then, the liquefied nitrogen is led to a liquefied nitrogen pump 3 by a certain volume by a low-pressure nitrogen tank 1, and after having been entirely gasified, it is discharged to the atmosphere through a gas-liquid separator 4 by the nitrogen blow valve 8. Volume of gasification decreases with progress of the pre-cooling, liquid level in the gas- liquid separator 4 rises and volume of discharge of gas from the nitrogen blow valve 8 comes near to zero. When the liquid level became higher than a set value of the contact-equipped liquid level gauge 13' of the gas-liquid separator 4, a switch 12 of a motor 11 is closed to start the liquefied nitrogen pump 3. It is possible, by doing so, to shorten the starting time and reduce size of the equipment.</p> |
