HRP980427A2 - Belt drive of a cargo pump power supplied from the main engine/engines on the tanker transporting products and chemicals - Google Patents

Description

The field to which the invention relates

The invention relates to shipbuilding, it is exclusively applied to tankers that transport products, i.e. oil derivatives and chemicals, and more closely relates to the system for loading/unloading liquid cargo.

Technical problem (the solution of which requires patent protection)

Known versions of systems for loading/unloading cargo from tankers for transporting products and chemicals are very complex, expensive and operate with large losses in energy conversion. Older, simpler designs do not provide the capabilities that are required today in modern tankers.

State of the art

On tankers, the cargo loading/unloading system is solved in two common ways:

1. Version with pump station (dry area in front of engine room where all cargo pumps are located)

2. Version with submersible pumps (in each cargo tank there is a separate pump, as a rule driven by a hydraulic motor)

Version 1 is suitable for tankers of all sizes that transport a maximum of 3-4 types of cargo at the same time (crude oil, derivatives, or cargo transported in large quantities). Version under 2 is suitable for tankers that transport several types of cargo at the same time (5-8 and up to 16-20), in which case it is a matter of smaller quantities of chemicals that cannot individually exceed 3000 m3 or 1250 m3 for tankers of type 2 or 1 according to the IBC Code. The most commonly built tankers today are 30-47,000 t capacity with the possibility of transporting products and chemicals (Oil and Chemical tanker). For such ships, the version with a pumping station is not suitable, because placing the required number of small pumps in the pumping station and passing the pipes of various, often incompatible cargoes through the cargo space would be unacceptable in terms of available space, applicable regulations and performance costs. The version with submersible pumps is extremely expensive and implies separate pumps in the left and right tanks, which is usually of no use, because on deck both tanks are connected to one unloading/boarding port and serve the same cargo.

In addition, due to several consecutive energy conversions (diesel engine-generator, electric motor - hydro pump, hydro pump - hydro motor), the utilization of this system as a whole deteriorates. As a rule, the power of the electrohydraulic installation does not allow the simultaneous operation of all cargo pumps, which means that even when unloading a large amount of the same cargo, the ship must be unloaded in two sequences, which prolongs the ship's stay in the port.

Presentation of the essence of the invention

The invention combines the good sides of previously known cargo handling systems on tankers and opens up a whole range of new possibilities and benefits. The essence of the invention is a simple mechanical drive, without losses in energy conversion, of all cargo pumps that are distributed along the length of the ship as in the version with submerged pumps, but are nevertheless located in a dry space - a longitudinally placed pump station within the structure of the longitudinal central bulkhead.

Today, a lot of attention is paid to the safety of the operation of modern tankers for the transport of oil and especially dangerous chemicals, and two drive machines are often installed that drive one screw via a reducer.

In addition to the power output from the reducer to drive the shaft generators, one output can be provided on the front side in the middle between the machines, (1) with a suitable elastic/flexible coupling (2). The power and number of revolutions of the output are chosen as desired, usually up to 3000 kW and 1500-1800 revolutions per min. Through the gas-tight seal (3), this shaft (4) enters the lower - double part of the longitudinal central partition (5). The longitudinal central partition is most often of vertical-corrugated design, but in the lower part, for reasons of strength, the partition is usually made of a double, trapezoidal section. This space is normally used for ballast, which on ships of this size is more than required according to international regulations anyway. The shaft (4) can be hollow, or composite with ball bearings (6) (roller two-row self-adjusting). Pulleys (7) for belt (8) power transmission to the cargo pumps (9), tank assembly (10), ballast (11) and bilge (12) are inserted at the necessary places along the shaft.

In the basic version, one pump is provided for a pair of cargo tanks since they usually contain the same cargo. Each individual pump is switched on/off by means of a remote (and locally) controlled excellent clutch (13). The pumps are practically located below the suction point so that with a proper design of the bilge well (14) a tank can be completely dried without a device for varying the speed of rotation of the pump or special drying systems that are often installed on tankers with a pumping station. If it is desired to avoid any mixing of loads, if they are different in the left and right tanks, 2 pumps will be installed instead of one (which also implies separate deck connections for unloading).

Control of the valves (15) is remote from the control station, but also local. A backup connection (16) of two adjacent pumps can be provided in case of failure of one of them. The descents to the longitudinal pumping station are located at the beginning and end of the cargo space. These trenches are also used for fan ventilation. The emergency exit can be at the junction of the longitudinal and transverse partitions. Although the flooding of a space of these dimensions does not significantly affect the behavior of the damaged ship, watertight doors can still be provided in two places in the tank that would prevent all pumps from being put out of use at once when water penetrates into one part of the tunnel - the pumping station. Floors (17) were installed along the tunnel for communication, access to pumps and valves, and maintenance. If necessary, due to overhaul, heavier parts are lifted and transported by trolley (18) on the upper rail (19). There is no electrical equipment in the tunnel - except for explosion-proof lighting and connections for indicating the operation of pumps and couplings. In the event that the installation of a bow thruster is foreseen, (20) which is often the case today, the shaft can be extended through the bow crash barrier in order to drive the bow thruster via the excellent clutch (21) and angle reducer (22) (only with pivoting wings). .

Brief description of the drawing

Fig.1 shows the floor plan of the tanker and the position of the longitudinal pump station, drive shaft and pumps in relation to the cargo tanks and the engine room.

Fig. 2 shows a detail of the belt drive of the pump

Fig. 3 shows a section of the tunnel - pumping station

Detailed description of the method of realizing the invention

All components of the system, such as the power take-off from the reducer, excellent couplings, shaft line with bearings and gas-tight seal, belt power transmission, cargo pumps, valves and piping, are used every day in engineering and shipbuilding. The selection and/or dimensioning of components is done on the basis of the required power and number of revolutions of consumers, i.e. pumps. Piping on the pressure side of the pumps is done as in systems with submersible pumps. As usual, coils with a steam connection are used for heating the load. In cases where a slow-moving machine with a non-rotating screw is used for propulsion of the ship, an excellent clutch should be installed between the machine and the screw, and an excellent power output with an increase in the number of revolutions (multiplier) to drive the axle/load pump should be installed at the front of the machine.

Method of application of the invention

The invention is expected to be applied in shipbuilding on tankers for transporting products and chemicals with a capacity of 5,000 to 47,000 t due to the following advantages:

1. It is cheaper than standard versions - when the cargo system is considered separately, but also when comparing the ship as a whole with all the consequences arising from the diversity of the propulsion complex and supporting systems.

2. Energy savings in operation - about 25 to 30 percent compared to the diesel-electrohydraulic system of submersible pumps, or about 8 to 10% compared to electric motor-driven pumps in the pumping station.

3. Safety in operation and ease of maintenance

a) It is possible to build the pump while the tank is full,

b) It is possible to use a second pump through the auxiliary pipeline in an emergency, whether separate pumps are provided for each tank or one for a pair of tanks.

c) All valves are accessible - possibility of local control if it fails remotely

d) All parts are easily removed from the pumping station for overhaul

e) Belt transmission does not require maintenance

f) Due to the tubular shape of the pump station, the ventilation is much more intense for the same amount of inserted/extracted air than with a classic pump station.

4. Simultaneous operation of all pumps at full capacity is possible, regardless of the power and number of pumps, since the main machine/machines always have at least twice the power required.

Claims (4)

1. It is requested to patent the belt drive of the cargo pumps by deriving power from the main machine/machines on the tanker for the transport of products and chemicals, indicated by the fact that the cargo pumps are arranged as in systems with submerged hydraulic pumps, i.e. directly next to the tanks they serve with the difference that the pumps of the patented systems are not immersed in the tank but are located in a dry area, in one long pumping station located inside the lower double part of the central longitudinal partition and are driven by a belt transmission from one longitudinally placed shaft that uses the power of the main machines via the output of the reducer. 2. Belt drive according to claim 1 characterized by the fact that the left and right tanks have their own pumps. 3. Belt drive according to claim 1 or 2, characterized by the fact that the power of one, as a rule, slow-moving main machine is used, so that a multiplier is installed between the long shaft and the machine to increase the number of revolutions. 4. Belt drive according to claim 1, 2 or 3, characterized by the fact that the long shaft is extended through the partition in order to drive the bow screw with turning wings via an excellent clutch and an angle reducer.