The invention relates to a bottom well and sea water piping system for vessels with which system the supply of sea water is provided for a vessel for both cooling water and other use. A bottom well and sea water piping system for vessels comprises a bottom well, pumps, filters, motors of the pumps with a frequency converter, an inlet and an outlet piping with equipments, and regulating devices.

Bottom wells are conventionally arranged on the vessel's boards in such a manner that part of the well is on the bottom side and part of the intake opening on the board side. Conventional bottom wells are naturally arranged below the water level in such a manner that all the water intake openings are below the water line. Bottom wells on both boards are most often connected by a common suction piping. A connecting suction pipe is arranged below the water level and it acts as a bypass manifold to which pumps are connected. Filters are also arranged on the suction pipe.

The greatest drawback of the conventionally used bottom well systems for vessels has been that the system is almost completely located below the water level. In that case there is always a risk in connection with disturbances and damages that water will gain access to the vessel's inner parts. Conventional bottom well and sea water piping systems normally have several pipe connections to the bottom well below the sea level. One or more suction pipes are connected to the bottom well. Furthermore, a return pipe for warmed water, an air pipe, possible lead-throughs required by compressed air or vapour blasting and lead-throughs of a heating spiral are also connected to the bottom well. It is clear that the above-mentioned lead-throughs arranged

below the water level will always be risky. In northern conditions, in particular, bottom wells arranged on the boards are not a very good solution because ice and ice sludge in the sea will often prevent the water intake from the bottom well. It has also been problematic that conventional bottom wells are placed in the most crammed place on a vessel, that is, in the forebody of the engine room. The two bottom wells there and the piping connecting them take an inconsiderably large space. Also, filters and the necessary pumps have often been a problem with regard to their logical placing.

Conventional bottom well and sea water piping systems have also been problematic for users since bottom wells easily accumulate air and ice because of the position of the wells. The removal of ice requires additional heating and attending to the heating. Air causes malfunctions in the pumps and as ice accumulates in the bottom well or the filters, the flow of cooling water is prevented. The bottom well and sea water piping system for vessels according to the invention eliminates the above- mentioned drawbacks and it is reliable and user- friendly. The bottom well and sea water piping system for vessels according to the invention is characterized by what is described below in the characterizing part of claims.

The greatest advantages of the bottom well and sea water piping system for vessels according to the invention will thus be the improvement of security and the lowering of the total cost. All parts of the system, piping as well as the openings in connection with the bottom well, are arranged above the sea level so that water will not gain access to the vessel's inner parts in cases of piping or other damages. The bottom well of the invention is in the vessel's midship, whereby it is

possible to accomplish advantageous device and piping- arrangements, which will essentially reduce the number of pipes, for example. Neither is it necessary to lay pipes transversely in the system of the invention. The position of the bottom well of the invention in the midship prevents air from entering the well, and a very slow flow in the bottom openings will not easily draw bay ice in with them. Furthermore, there is very little ice in the bottom well situated on the vessel's middle line due to a long distance from the bow. The cost of the piping of the invention is lowered e.g. by that piping above the sea level does not need the security systems required by the classification societies. Also, energy is saved in the system of the invention in which an optimal amount of water constantly flows according to each operating situation. The regulation of the system is simple and it is performed by means of two regulating valves with which both temperature and pressure are regulated. In the following, the invention will be described in detail with reference to the accompanying drawing.

Figure 1 is a schematic representation of a bottom well and sea water piping system for vessels according to the invention.

In Figure 1 numeral 1 refers to a submersible pump and numeral 2 to an electric motor or the like driving the pump. The operating speed of the motors 2 is regulated by means of a frequency converter 3. Numeral 4 refers to a temperature regulator and numeral 5 to a pressure regulator. The amount of return flow to the bottom well is regulated by means of a heat regulating valve 6. The amount of water discharged from the vessel is regulated with a pressure regulating valve 7. A back water valve is referred to by numeral 8 and

filters by numeral 9. A bottom well is indicated by numeral 10 and the vessel's cooling points by numeral 11. The vessel's bottom is indicated by numeral 12, a double bottom by numeral 13 and a middle deck by numeral 14. The measurement of temperature is performed by means of a temperature sensor 15 and the measurement of pressure by means of a pressure sensor 16. A control and supervision unit is indicated by numeral 17. Numeral 18 refers to an inlet piping of the system and numeral 19 to an outlet piping. A covering plate of the well 10 is indicated by numeral 20, walls by numeral 21 and bottom openings by numeral 22. A step ladder 23 is secured on the wall 21 of the bottom well 10 for checking and maintenance. The cooling circuit of the main engine is equipped with an automatic valve 24.

The bottom well and sea water piping system for vessels according to the invention conducts the supply of sea water needed on the vessel. As almost all parts of the system are above the sea level, except for the bottom well 10, the maintenance of the pumps 1 is also easy to carry out. Similarly, the repair and maintenance of the piping can be done without docking the vessel . A sufficient amount of water is pumped by means of the pumps 1 to the cooling and moving water network 18, 19, depending on the purpose of use. The inlet water flow is regulated in the cooling and other points of use 11 by means of the frequency converter 3 which controls the motors 2 of the pumps 1. The total control is accomplished by means of the programmable control and supervision unit 17. The temperature of the cooling water of the system is measured by means of the temperature sensor 15 with which the return flow to the bottom well 10 is controlled via the temperature regulator 4 by means of the heat regulating valve 6. The pressure of the piping is measured by means of the

pressure sensor 16 with which the amount of water discharging from the vessel is controlled via the pressure regulator 5 by means of the pressure regulating valve 7. The bottom well 10 arranged on the vessel's middle line may be of a desired physical shape. The well can be made highly stress-resistant by constructing a round well . The step ladder 23 is secured on the side walls 21 for maintenance. The grates acting as filters 9 are easy to maintain. It is also possible to have them detachable so that they can be removed through the covering plate 20 for maintenance. If needed, the bottom grate can also be constructed in such a way that it may be removed through the covering plate 20. Since the cooling of the main engine generally consumes most energy on vessels, the sea water piping system of the main engine should be equipped with a separate automatic valve 24 which closes as the main engine is stopped. Automatic valves 24 can also be mounted on other consumers of water.

It is evident that the bottom well and sea water piping system for vessels according to the invention may vary a great deal within the scope of the idea of the invention. The number of pumps in connection with the bottom well 10 may vary as needed. It is also possible to equip the bottom well 10 with separate fire pumps or pumps intended for a corresponding purpose of use. Also, the position of the well 10 can vary depending on the type of vessel, and the well 10 can be placed in the most preferred position with regard to the vessel's construction. The types of pipes may vary according to the purpose of use. The control system of the sea water piping can also use known computer or the like systems and gain desired advantages depending on the preferred stage of automation.