A kind of spiral liquid nitrogen freezer and method

Abstract

The invention provides a spiral liquid nitrogen freezer and a freezing method, which are suitable for the artificial freezing construction of underground engineering. The spiral liquid nitrogen freezer comprises a liquid supply pipe and a return gas pipe, wherein the liquid supply pipe and the return gas pipe are of spiral structures, are interconnected and are respectively provided with a liquidsupply pipe orifice and a return gas pipe orifice; and the tail ends of spiral coils of the liquid supply pipe and the return gas pipe are interconnected, are in staggered arrangement and not in direct contact with each other. The spiral liquid nitrogen freezer has less loss of refrigeration capacity, and gives full play to the characteristic of the rapid freezing of liquid nitrogen. The spiral liquid nitrogen freezer is directly close to the stratum needing to be frozen, improves the efficiency of the transfer of refrigeration capacity into the stratum, and gives full play to the advantage ofhigh refrigeration efficiency of liquid nitrogen. The spiral liquid nitrogen freezer can be directly applied to the stratum freezing engineering at different depths; and the freezing effect at different depths can be controlled by adjusting the interval between spiral pipes so as to achieve the differential freezing at different depths.

Description

technical field [0001] The invention relates to a spiral liquid nitrogen freezer and a method, in particular to a spiral liquid nitrogen freezer and a method suitable for artificial freezing construction of underground engineering. Background technique [0002] During the construction of urban underground projects, when crossing complex geological conditions such as weak water-rich sandy soil layers, artificial freezing technology is often used to strengthen the ground and improve the performance of the ground, so as to complete the construction of underground projects in water-bearing strata, and the liquid As an efficient and time-saving freezing method, nitrogen freezing has been widely used in municipal underground engineering. The liquid nitrogen freezer currently used in liquid nitrogen freezing is structured to insert a liquid supply pipe with a smaller diameter inside the steel freezing pipe to form a freezing circulation system. When the liquid nitrogen is frozen, ...

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Problems solved by technology

Moreover, the nitrogen gas discharged from the nozzle of the freezing tube is directly discharged into the atmosphere after heat exchange with the liquid nitrogen in the liquid supply tube, which greatly increases the loss of liquid nitrogen cooling capacity.

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