SE505577C2 - Seawater and exhaust systems in a motor installation in a boat - Google Patents

Abstract

Seawater and exhaust system in a marine engine installation, comprising an outlet conduit (12) from a water heat exchanger (11) to the engine exhaust pipe bend (15). The outlet conduit extends from the heat exchanger upwards to a point (21) above the waterline and from there down to the exhaust pipe bend. The downwardly directed conduit section (12b) has such a large flowthrough area relative to the waterflow that air and exhaust can easily pass from the exhaust system up to the highest point when the engine is shut off.

Description

505 577 2 and that at least the part of the outlet line which extends from the highest point down to the exhaust line has a flow area which is greater than what the capacity of the pump requires.

Through this design, a line is obtained in which the siphoning effect cannot occur. The pipe thus has such a large cross-sectional area in relation to the water flow that air / gas can easily pass from the exhaust system up to the highest point of the pipe and allow the pipe to be emptied of water. This prevents siphoning and the risk of water penetration into the engine is thus eliminated without the use of valve devices, the function of which may be lost as a result of clogging.

The invention is described in more detail with reference to exemplary embodiments shown in the accompanying drawing, in which Fig. 1 schematically shows an engine installation in a boat and Fig. 2 shows an enlargement of a part of the installation in Fig. 1.

In Fig. 1, 1 denotes a boat bottom and 2 an adjoining transom. On a motor bed 3 fixed to the bottom 1, a motor 4 is mounted on motor cushions 5. The motor 4 has a seawater pump 6, which has a suction line 7 connected to a bottom bushing 8 and a pressure line 9 connected to the inlet 10 of a heat exchanger 11 , for cooling the engine coolant. An outlet line, generally designated 12, connects the outlet 13 of the heat exchanger 11 with the inlet 14 to a water-jacketed so-called "exhaust bend" 15, as shown more clearly in Fig. 2.

From the exhaust bend 15, an exhaust line 16 extends via a muffler 17 to an outlet 18 for water and exhaust gases in the transom of the boat 2. The aft part of the exhaust line 16 is designed as a so-called "gooseneck" 19, the highest point of which is higher than the water level 20, i.e. the actual waterline of the boat, to prevent water from entering the engine the rear way from the outlet 18. 505 577 3 To also prevent water from filling the exhaust line through the siphon action via the seawater pump 6, line 9, heat exchanger ll and outlet line 12, so that water penetrates the engine, the outlet line 12 is designed in a manner that prevents siphoning.

As most clearly seen in Fig. 2, the outlet conduit 12 consists of a first vertically directed conduit section 12a and a second vertically directed conduit section 12b, with larger diameters than the section 12a. These are connected to each other by means of a U-shaped splice pipe 21, which - as can be seen from Fig. 2 - lies above the seawater level 20. The cross-sectional area of the pipe section 12a is dimensioned for the water flow, i.e. for the capacity of the pump, while the flow area of the line section l2b is greater than what the capacity of the pump requires. In a practical embodiment with a water flow of 30 liters per minute, a pipe section 12a with a diameter of 15 mm and a pipe section 12b with a diameter of 25 mm were chosen. The line section l2a can of course also have the same diameter as the section l2b. The most important thing is that the highest point 21 of the outlet pipe 12 lies above the water surface 20 and that the pipe 12b from the highest point and to the exhaust bend 15 has such a large flow area in relation to the water flow that air and exhaust gases can pass from the exhaust system up to the splice pipe. 21, when the engine is stopped.

Claims (4)

10 15 20 25 30 505 577 4 Patent claims A seawater and exhaust system in an engine installation in a boat, comprising a water pump, a suction line connected between the water pump and a water inlet, a pressure line connected between the water pump and an inlet to a heat exchanger and an outlet line connected between an outlet of the heat exchanger and an inlet to an exhaust line, which lies wholly or partly below the waterline of the boat, characterized in that the outlet line (12) has a highest point (21), which is higher than the waterline (20) of the boat (1, 2), and that at least that part (l2b) of the outlet line, which extends from the highest point down to the exhaust line, has a flow area which is greater than what the capacity of the pump requires. Seawater and exhaust system according to claim 1, characterized in that the part (l2b) of the outlet line, which extends downwards from the highest point to the exhaust line, has a larger flow area than the part (l2a), which extends upwards to the highest point . Seawater and exhaust system according to claim 1 or 2, characterized in that the outlet line has an ascending and a descending line section (12a, 12b), which at the highest point are connected to each other by means of a joint (21) and that the descending the line section (l2b) has a larger flow area than the ascending line section (l2a). Seawater and exhaust system according to one of Claims 1 to 3, characterized in that the outlet line (12) opens into a water jacket around an exhaust bend (15) connected to the engine.