RU2067141C1 - Method of conducting freezing-out jobs - Google Patents

Abstract

FIELD: shipbuilding; forming passages to structural members under repair for ships blocks in ice. SUBSTANCE: method consists in making lanes in ice on either side of hull of ship under repair. Flexible envelope 1 is passed through lanes under ship's hull; then cold air is forced into this envelope supplied from supercharger 5; pressure inside envelope is kept at level slightly exceeding the hydrostatic pressure of water. Required pressure is built up by means of pressure-reducing valve 4 which ensures overflow of air through flexible envelope 1 at further charging of air. After ice walls of required thickness are formed around envelope 1 being blown, hot air is forced into envelope 1; hot is obtained by means of air heater 6 connected to supercharger 5. Flexible envelope is freed from ice and is withdrawn outside. Fuel freezing-out is performed by standard methods. EFFECT: enhanced reliability. 2 cl, 1 dwg

Description

 The method relates to the technology of ship repair and for the formation of viaducts in order to provide leads to the repaired structures of ships located in ice.

 There is a method of performing freezing work, applicable to the formation of leads to the repaired section of the ship's hull, namely, that the inflatable shell is pumped with cold air to freeze ice on it (see AS USSR N 1124096, class E 02 B 17/00 1983 g).

 However, it is ineffective, unreliable and time-consuming.

 The technical result of the invention is to increase efficiency, reliability and to reduce the duration of freezing.

 This is achieved by the fact that in the ice near the ship’s hull, lanes are made through which the shell is passed under the ship’s hull before it is pumped with cold air, which is produced at a pressure higher than hydrostatic pressure, and this pressure is also maintained when air is passed through the inflatable shell, which is then removed from the ice cover along with ice at the places of approach to the hull.

 In addition, the inflatable shell is pumped with heated air before it is removed from the ice sheet.

 The drawing shows a diagram of the freezing of the ice walls of freezing.

 A device for implementing the method consists of an elastic inflatable shell 1 with discharge and outlet pipes 2 and 3, respectively. The pipe 3 is equipped with a pressure reducing valve 4, and the pipe 2 is connected with an air blower 5 equipped with a heater 6.

 The method is implemented as follows.

 Ice is being opened in the area of future freezing from both sides of the repaired vessel. After that, elastic lining 1 is introduced into the resulting lanes under the ship’s hull (see drawing). Eyeliner shell 1 can be carried out in various ways, for example, using diving operations. Another option for the liner can be an early establishment in the area of the future freezing around the hull of the ship steel cable. Moreover, the cable should have sagging under the hull so that it does not turn out to be completely frozen in ice. After cutting the lanes from both sides of the vessel, the cable will be released from the ice at the sides of the vessel, and the sheath 1 fixed to it can be carried out under the hull by juggling the cable. Next, the shell 1 is pumped with cold air, thereby displacing the required volume of water in the zone of future freezing. The required pressure (slightly higher than the hydrostatic pressure from the shell deepening in the water) in the shell is achieved by means of a pressure reducing valve 4, which, when the air is further pumped into the shell, ensures its flow through the latter. As a result of the selection of heat by the cold air blown through the shell, ice freezes around it, which is done until the ice walls reach the required size. Then, the casing 1 is blown with hot air, which is obtained by connecting to the operation of the air-blowing device 5 (for example, a fan) of the heater 6. Blowing with hot air will release casing 1 from the frozen ice, although it is made of water-repellent material (for example, polyethylene), but due to the complex configuration of the vessels, folds form on it, freezing in ice and preventing them from being taken out of the cold. After removing the shell 1, ice is sampled to the ship's hull using conventional methods. If it is inexpedient to remove the shell 1, which may be caused by the need for longer frost preservation or the absence of air-heating sources, the shell is destroyed along with ice at the places of approach to the ship's hull.

 The present method of carrying out freezing operations can significantly reduce the time and complexity of their implementation, and also increases their reliability by protecting the freezing of the elastic membrane during ice cracking.

Claims (2)

 1. The method of performing freezing work, mainly for forming leads to the repaired section of the ship’s hull, namely, that the inflatable shell is pumped with cold air to freeze ice on it, characterized in that lanes are made in the ice of the ship’s hull through which the shell is passed under the hull of the vessel before pumping it with cold air, which is produced at a pressure higher than hydrostatic, and this pressure is also maintained when air is passed through the inflatable shell, which is then removed They are removed from the ice cover together with sections of ice at the places of approach to the hull.  2. The method according to claim 1, characterized in that the inflatable shell is pumped with heated air before it is removed from the ice sheet.