Unplugging-free freezer

Abstract

The invention discloses an unplugging-free freezer used in tunnel construction, which mainly solves the problems of easily damaged cutter head, long time-consuming construction and high cost of the conventional freezer during the advance of a shield. The unplugging-free freezer is characterized in that: a freezing pipe (3) and upper and lower blanking plates (6,7) are all made of thin-walled aluminum or copper materials; a thick-walled plastic pipe (4) is arranged in the freezing pipe (3), wherein grooves (9) are formed at the outer periphery of the thick-walled plastic pipe (4) and central holes communicated with a feed pipe (1) are formed in the thick-walled plastic pipe (4); and strutting pieces (5) are arranged between the thick-walled plastic pipe (4) and the lower blanking plate (7). The freezer can be left in a frozen soil wall without being unplugged after the frozen soil wall reaches a designed thickness; the front end cutter head of the shield can easily cut the freezer distributed in the frozen soil wall without damaging the cutter head in construction, so the project cost of a project can be effectively reduced, the project period can be shortened, and the project risk can be reduced.

Description

technical field [0001] The invention relates to a freezer suitable for strengthening the soil at the entrance and exit of a shield tunnel by freezing method in tunnel construction, in particular to an unplug-free freezer suitable for conventional low-temperature salt water freezing and rapid liquid nitrogen freezing. Background technique [0002] The principle of the freezing method to strengthen the soil at the entrance of the cave is to freeze the water in the soil, and the soil in the entire freezing range temporarily forms a frozen solid with considerable strength. In the door ring, the hole sealing device is installed, and the sealing performance of the hole construction is established, etc., then thaw and enter the normal entry and exit hole construction. Because the frozen soil wall reinforced by the freezing method has the characteristics of good uniformity and high strength of the frozen soil wall, the underground diaphragm wall and the frozen soil wall are well bon...

AI Technical Summary

Problems solved by technology

At present, there are many deficiencies in the construction method of the pull-out freezer used: 1) The steel has low-temperature brittleness. During the process of pulling out the freezer, the freezer is easy to break from the welding position. Once the freezer breaks, part of the freezer remains. In the frozen soil wall, the shield can only be forced forward, resulting in damage to the cutter head, resulting in economic losses and delays in the construction period; 2) When using rapid liquid nitrogen freezing, on the one hand, the temperature of the frozen soil wall formed by the freezing of liquid nitrogen is extremely low , the high-temperature brine circulating in the freezer may freeze. Once it freezes, the treatment will take a long time, which will seriously affect the progress of the project; on the other hand, the freezers used for rapid liquid nitrogen freezing are all made of stainless steel, and the cost is extremely high; 3 ) Melting the soil around the freezer will consume a lot of energy and increase the project cost; 4) The process of pulling out the freezer itself consumes time and delays the construction period

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