JPS59184095A - Device for preventing freezing of tank in ice breaker - Google Patents

Abstract

PURPOSE:To employ a small capacity of heat of a heating device for preventing freezing of a tank interior, and thereby to aim at saving of energy, by providing water sprinkler nozzles over an outside surface of a tank side wall, so as to form a frozn layer showing a heat insulating effect on the outside surface of the tank side wall adjacent to the atmosphere. CONSTITUTION:Water sprinkler nozzles 4 are provided over an outside surface of a side wall of a hull through openable valves 7 and branch pipes 8 connected in equal intervals to a water feed pipe 3 as disposed on an upper deck 2. When a ship enters a frozen sea, water is sprinkled from the nozzles 4 onto the outside surface 1 of the hull side wall to form a frozen layer 9. The frozen layer 9 may be utilized as a heat insulating layer because ice has a small heat conductivity. In other words, it is possible to employ a small capacity of heat of a heating device for preventing freezing of a tank interior by utilizing a heat insulating effect of ice.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antifreeze device for tanks in ice-water vessels.

Ships navigating in icy waters encounter harsh outside temperatures of around -50°C. Therefore, in tanks that are in contact with the outside air, such as ballast tanks, the
−′“0.

There is. For example, if ice remains in the tank when ballast water is discharged at a loading port, either reduce the load by that amount or enlarge the cargo (oil) tank in advance. On the other hand, it requires a large amount of equipment and energy to heat the inside of the tank to prevent it from freezing and to thaw frozen ice just before loading.

The purpose of this invention is to focus on the fact that the thermal conductivity of ice is lower than that of water, and to utilize the heat-insulating effect of ice to prevent freezing of tanks such as ballast tanks that are in contact with the outside air using less energy. It is something to do.

In order to achieve the above object, the anti-freezing device for a tank according to the present invention is provided with a water nozzle for forming an ice layer connected to a water supply pipe above the outer surface of the side wall of the tank that is in contact with the outside air, and a water nozzle for forming an ice layer connected to the water supply pipe. A heating tube for forming a molten water film is installed in the tank, and heating tubes for heating the tank are installed at required locations inside the tank.

As described above, the tank antifreeze device according to the present invention has a water nozzle for forming a frozen layer connected to the water supply pipe above the outer surface of the side wall of the tank that is in contact with the outside air, so that when a ship enters an icy area, , Water is sent to the water supply pipe and sprayed from the nozzle on the outer surface of the side wall of the tank, forming a layer of ice that has a heat-insulating effect on the outer surface. On the other hand, heating pipes for heating the tank are installed at required locations within the tank, so the water in the tank is heated to prevent it from freezing, but the presence of the freezing layer reduces the amount of heat that enters. , the heating equipment can be made smaller and the energy saving effect can be achieved.

When it is no longer necessary to heat the tank, a heating tube for forming a molten water film is installed along the inner surface of the tank side wall that is in contact with the outside air. A film of melt water is formed on the surface of the ice, reducing the adhesion of the frozen layer and allowing it to fall by gravity. The energy at this moment is
This is clearly less than the energy needed to create a layer of ice in the tank and melt it all.

An embodiment of the invention will be described below with reference to FIG.

The antifreeze device shown in the same figure is installed at a predetermined distance between the water supply pipes (3) on the upper deck (2) above the side wall (1) of the ballast drainage work ('r) that is in contact with the outside air, that is, the outer surface of the ship's side shell plating. Water nozzles (4) are provided to a large number of ice-forming imaging devices 1 connected via branch pipes (8) equipped with on-off valves (7) at every interval, and water nozzles (4) are provided on the inner surface of the same side wall (1) to melt the water. A heating tube (5) for forming a water film is disposed, and a heating tube (6) for heating the tank is further disposed in the middle of the height of the tank.

When the ship enters an icy area, seawater is sent to the water supply pipe (3) and sprayed from the nozzle (4) onto the outer surface of the side wall (1), forming an ice layer (9) there. The side wall (1) is slightly inclined as shown in the figure to facilitate the formation of this ice N (9). The increased weight of the ship due to the formation of the ice layer (9) operates the ballast pump (1o),
By discharging ballast water overboard from the drain pipe (11) of tank (1), the water can be adjusted to a predetermined level.

The lower surface of the frozen layer (9) is melted by the heating pipe (5) in conjunction with the ballast drainage work at the loading port.

Figure 2 shows the first steps to peel off the ice formation.
This figure shows a modification of the inclined side wall shown in the figure, and (A) shows the side wall (1
) has horizontal flat bars 02 fixed in several stages to the outer surface, (B) has half pipes (13) fixed in several stages, and (C) has a net α4 suspended.

The present invention is also applicable to live water tanks that are in contact with outside air, outside of ballast tanks.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing three modified examples of the outer surface of the side wall for facilitating the formation of a frozen layer. ('r)...tank, (1)...tank side"J,
f3) m" water supply pipe, (4)...Water nozzle for forming freezing level, (5)...Heating tube for forming melt water film, (6)...
・Heating tube for tank heating.

Claims (1)

[Claims] A water spray nozzle for forming a frozen layer connected to a water supply pipe is installed above the outer surface of the side wall of the tank that is in contact with the outside air, and a heating pipe for forming a molten water film is installed extending over the inner surface of the same side wall. A tank antifreeze system for ice-water vessels that has heating pipes installed at required locations to heat the tanks.