FI60680B - SYSTEM FOER TRANSPORT AV VAETSKEFORMIGA PRODUKTER - Google Patents

Description

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C (45) Patent granted on 10 03 1932 iFatent aeddeiat (51) Kv.ik? /Int.a.3 B 63 B 27/24, P 04 P 1/06 ENGLISH —FL N LAN D (21) P »» nttlH »k * mu« - PatenUMeknlng 3173/7 * + (22) H »k« ml »pWvi - AiMeknlngtdag 29.10.7 * + '' (23) Alkuptlvt — Glltif h * t * dif 29.10.7 * + (11 ) Explore Public - Bltvlt offentilg 02.05 * 75

Patent and Registration Office .... .......... . ,, (44) NlhtivUulpanon ja kuL | ulkal * un pvm. -

Patent-and-Register Office 'An * ök »n utbgd och uti.« Crypt «n pubUc * r» d 30.ll.8l (32) (33) (31) (US) U118U8 (71) (72) Robert G. Wolff, 955 Crystal Street, Nev Orleans, LA 70121+, USA (US) (7 * +) Berggren Oy Ab (5 * +) Liquid Product Transfer System - System för transport av ötskeformiga produkter

The present invention relates to a system for conveying liquid, sludge or similar flowable substances, which system is of the type set out in the preamble of claim 1. Examples of such systems are compressed air pumps, pulse meters or pumping systems known from U.S. Patents 2,145,540, 1,783,747 and 3,405,648, which comprise a plurality of tanks adapted to supply a gaseous pressure medium, such as compressed air or steam, via suitable control valves. . Once the contents of the container have thus been removed, the pressure medium in the container is either removed only through an outlet valve directly into the atmosphere so that the container can be filled with a new charge, or sucked out by a vacuum which can contribute to the new charge. It has often been hesitated to use such systems, not least in ship pumping systems, and especially because emptying the contents of the tank consumes very large amounts of gaseous pressure medium.

U.S. Pat. No. 2,60680 discloses a pumping system in which liquid is pumped from a plurality of tanks by means of pressurized nitrogen gas so that the tanks are depleted and filled alternately under the control of an automatic control system with the gas system closed. However, if air is used as the pressure medium instead of nitrogen gas, the gas system is not closed, and after emptying the tank, the compressed air is removed directly into the atmosphere, which is accompanied by the above-mentioned drawback.

The system according to the invention is characterized by what is shown in the characterizing part of claim 1. In this case, the above-mentioned drawback is eliminated or reduced, as the system results in that part of the gaseous pressure medium, after being used to remove the contents, pumping chambers to avoid feeding additional amounts of gaseous pressure medium to pump the fluid to be pumped from the common fluid storage tank. The system is particularly suitable for use on ships carrying liquids, sludges or certain easily flowing dry bulk cargoes, but other uses may also be considered. In the following, gaseous pressure medium means not only compressed air, but also all other gaseous media which can be subjected to overpressure. By flowable material is meant not only liquids, sludges or similar fluids, but also dry substances, such as powders, which can be made to flow into and out of the tank and through pipelines. The invention thus provides a substantial improvement in benefit over known systems by reusing a portion of the exhaust gas that would otherwise be wasted.

Claim 2 details how the system is controlled to remove only that portion of the gaseous pressure medium whose overpressure is too low to be reused.

An additional benefit of claim 3 is that a larger amount of gaseous pressure medium is stored for later use, primarily to maintain the pressure in the storage tank during the second degassing step, also maintaining the removal rate until the next first degassing step begins, and secondarily for system start-up when the storage tank is refilled with the pumped liquid after the gas is removed from the pumping chamber.

The claim 4 provides that a portion of the gaseous pressure medium quickly enters the storage tank without significant pressure drop when the pressure in the storage tank is lower than a predetermined pressure, so that the storage tank quickly reaches its maximum working pressure in the first degassing stage.

In addition, what is claimed in claim 5 causes the pumping cavity to be filled more quickly with the substance to be pumped by the effect of the vacuum.

Claim 6 discloses a preferred embodiment of the system, wherein the removed gaseous pressure medium is also utilized to develop a vacuum in the vacuum container, which vacuum can be used, for example, to increase the pumping rate due to the suction effect on the pumping chamber.

Claim 7 discloses a system according to the invention adapted for use on a ship, whereby, in addition to reusing part of the removed gaseous pressure medium, a faster, easier and more complete emptying of the ballast or cargo tanks is achieved.

The invention will now be described in more detail with reference to the accompanying drawing, which shows a preferred embodiment of the invention and in which Figure 1 is a schematic diagram of a preferred embodiment of a basic pump system according to the present invention, Figure 2 is an isometric view of a preferred marine application according to the present invention. placement of the elements with the plurality of elements shown schematically with the general outline of the lottery vessel shown in dotted lines, Fig. 3 is a partial plan view of the marine embodiment of the present invention shown in Fig. 2, Fig. 4 viewed, Fig. 5 is a partial side cross-sectional view taken along lines 5-5 of Fig. 3 taken from the left side of the marine application, Fig. 6 is a perspective cross-sectional view of a special cargo valve "cover cap" "used in a cargo container in the preferred marine embodiment of the present invention, Figure 7A is a partial side cross-sectional view with some elements partially cut away from a special cargo port two-hole wafer-type supply valve used in the preferred marine embodiment end cross-sectional views of the cargo port feed valve shown in Figure 7A taken along lines BB and CC of Figure 7A, respectively.

Referring to Figure 1, the basic system comprises, for example, two pumping tanks P and S connected together by a line 4, which is further connected via a liquid supply line FL to the bottom of the liquid supply tank 42. The flow from the liquid supply tank is manually monitored via the liquid supply valve 3, while the flow to the pumping tanks is automatically monitored by means of liquid supply valves 5, one for each pumping tank, located between line 4 and the pumping tanks P and S.

The automatic control system provides the required opening and closing of the various valves in the correct order to perform the alternating filling and draining of the liquid by means of the pumping tanks, i. completion of the operating period. This control system can be specially designed or one of several standard types can be used; for example, it may be electrically or mechanically operated and triggered either by level indicators in the pump tanks or by a time period monitoring device or both.

The other parts of the system, their operation and use are described in the description of the operating cycle. In the initial situation, the supply valve of the pumping tank P has just been closed, the tank P is full of liquid and pumping medium, e.g. compressed air is supplied to it via line 13 and the entry of medium into the pumping tank P is automatically monitored via air supply valve 10. The supply air passes through the line 11 and the liquid in the tank P is drained from the bottom of the tank through the outlet line 18 and the control valve 19 to the common outlet line 20.

The monitoring system closes the valve 10 to cut off the supply air before the tank is completely emptied. This operation is immediately followed by the automatic opening of the primary exhaust valve 15, which allows the exhaust air from the tank P to flow through the line 11 to the primary exhaust line 15L, which is further connected to the line 27, first the exhaust air flows through the line 27 and further through the jet or vacuum pump 26. to the vacuum tank V via the control valve 28 and thus creates a vacuum of e.g. 508 mm Hg to the vacuum tank V.

Leaving the jet pump 26, the exhaust air flows along line 29 60680 to the exhaust air storage tank 32, where the air pressure 2 is maintained, for example, at 0.35 kp / cm by means of a pressure control valve 30 in line 29. A pressure control valve 34 is also connected to the tank 32, which reduces the pressure of the exhaust air 2 to 0.05 kp / cm before the air continues through line 34L to the liquid storage tank 42. As a result, the internal pressure of the liquid storage tank 2 rises to 0.05 kp / cm. the flow rate of the incoming liquid and helps to completely empty the tank, both of which are important when it comes to thick liquids.

2 This exemplary pressure of 0.05 kp / cm is the maximum value permitted for certain tanks, especially in barges and ships, in connection with certain pressure-vacuum valves which must be permanently installed in such tanks as safety devices. These are not shown in more detail in Figure 1. If the pressure in the line 29 exceeds the value of 0.35 kp / cm, then the excess pressure is removed to the atmosphere by means of a pressure control valve 30. The operations just described take place after the opening of the primary outlet valve 15, which is soon followed by the automatic opening of the secondary outlet valve 14. This latter operation releases the final exhaust air at a lower pressure into line 14L, which opens into the atmosphere via line 31L.

As another means of creating a vacuum, compressed air can be supplied directly from the line 13 to the jet pump 26 via a suitable direct connection (not shown).

Returning to the operating cycle, the automatic opening of the final discharge valve 14 is soon followed by the automatic opening of the supply valve 5 of the tank P, which allows the tank to be filled with liquid and after which the valve 5 closes automatically and the cycle for the tank P is completed. The same sequence of operations as described in connection with the pump tank P also takes place for the pump tank 7 60680, however, it is timed by means of an automatic monitoring system so that when the tank P is filled, the tank S is emptied and a continuous and uninterrupted flow of liquid is created. The operating cycle can be slowed down or accelerated by the control of an automatic control system, however, other factors such as compressor capacity, line size and viscosity of the pumped liquid also affect the operating speed.

In view of the use of the vacuum provided, the vacuum tank V is directly connected to a line 12L further connected via a shut-off valve 12 to a common air opening and an outlet line 11 to the pump tanks P and S. This allows vacuum to be used in pump tanks. or very valuable liquids, for drawing liquid residues into pumping tanks. Line 12L is also connected to line 25L via shut-off valve 25. This allows the vacuum to be used as a suction pump without the complicated arrangement of an independent power source and the consequent hazards when handling flammable liquids.

The present invention is suitable for use in a variety of applications, all of which would use the same basic system and principles of the present invention, however, with appropriate modifications to the floor plan, piping, etc. as required. For example, in the case of tankers with deep tanks and separate pump rooms, the safe pumping system of the present invention could well replace much of the hazardous pumping system.

The system according to the invention can be used e.g.

1. in barges operating on inland waterways, rivers and at sea; 8 60680 2. ships, such as oil tankers and other tankers; 3. tugs as auxiliaries or auxiliaries; 4. as an independent floating pumping unit with or without its own power supply; 5. as an independent onshore pumping unit with or without its own power source.

The most preferred embodiment is shown in section 1, i. the invention is used on inland waterways with and in barges on the high seas. Such an application is described in more detail below.

In the preferred embodiment for barges, the most active parts of the system are located in the pump room, which is usually close to the front end of the barge. The room extends across the barge, being on average 10.7 meters wide, 3.96 meters deep and 1.53 meters long in the longitudinal direction of the barge.

Referring to Figures 2, 3, 4 and 5, two cylindrical pumping tanks P and S (for the left and right sides) are located horizontally transversely to the barge in the same line and close to the bottom of the pump room. For example, each pumping tank can have a diameter of 76 cm and a length of 4 m. In barges without any hub separating cargo tanks, only one larger supply line is used. In general, the operating cycle and the automatic control system are similar to those previously described for the basic system,

The cargo supply valves 3, as shown in Fig. 6, are located at the bottom 50 of each cargo tank and have a special "cylinder cap shape" for complete emptying of the entire cargo. These valves can be about 50 cm in diameter and are operated manually from the deck by the steering wheels 2 'and attached by means of spindles 2, as shown in Figures 4, 5 and 6. If desired, the spindles 2 can be encapsulated to reduce friction. In the open position, the large openings, or notches 53, in the bottom of the outer cylindrical "cylinder cap" 54 allow the cargo to flow freely into the supply line FL, as shown in Figure 6. Opening or closing the valve by turning the steering wheel 2 'with the spindles 2 attached to it raises or lowers the cylindrical inner piston 51 to which the support plate 44 is attached.

The mandrel 2 is provided with a hollow flow channel 61 including a bottom opening 62 and an upper opening 63, which allow the liquid enclosed above the cylindrical inner piston 51 to be removed from the upper opening 63 into the cargo container. The support surface may be machined for intermetallic contact, as shown in the figures, and / or a plate of larger cross-section grooved for a flexible O-ring near the circumference of the plate may be used to provide a tight seal against the support flange 45 shown. Vertical guides not shown in the figure prevent the inner piston 51 from rotating relative to the outer housing 54 when the steering wheel 2 'and the spindle 2 are rotated.

The inlet valve 5 in each pumping tank is also designed in a special way. Figures 7A-C show details of this valve, which may be, for example, about 76 cm in diameter, and which may be made, for example, as a two-port rotary damper valve, as shown in the drawing. For example, the valves 5 can be mounted in a flange connection between the pumping tanks and the pipe body 4, providing good attachment and easy access to the valve and its automatic pneumatic actuator 52. Full opening or closing of the two-port during the cycle, the valve 5 has a minimum pressure. The steel springs shown in Figure 7A cause a constant pressure parallel to the pumping pressure to hold the valve against the seat. The arms 49 are supported by the pneumatic starter 52 and the drive shaft 48. The operative support members of the valve, i.e. the surfaces that are worn in normal use, can be turned upside down to provide non-wearing surfaces, thus extending the life of the valve.

The cargo supply lines FL can be, for example, 36 cm in size and are surrounded, for example, by a concentric 40 cm steam-heated line, i.e. a sheath HL, as shown in Figures 3 and 5. The steam required to heat thick liquid cargoes is supplied via line 40 and is controlled by manual shut-off valves 41 in each cargo tank, as shown in Figures 2, 3 and 5. Additional heating capacity is available via separate heating coils, not shown, but shown below. available as standard. Since the energy required to heat the cargo is lost, the heating should not be performed in excess of what is necessary to get the cargo pumped. Instead of heating the entire cargo in the tanks, a heating system is shown designed to heat only the cargo to be pumped. This reduced heating is particularly important in the context of oil cargo or similar handling, as the total heating of such cargo causes the light components to evaporate first, which are the most dangerous and volatile parts of the cargo. With such cargo, it is better to heat as little as possible. If desired, e.g. when handling asphalt or other similar loads, the pumping tanks P and S can be provided with a jacket for conducting heat to ensure the free movement of the supply valves 5.

Looking at the operating cycle in detail, this example assumes an operating speed of four full cycles per minute. Starting from a situation where the pumping tank P has reached the stage where it is almost empty 60680 or closed, the automatic monitoring system (ACS) closes the air supply valve 10 of the tank P. About half a second later the ACS opens the primary deaeration valve 15 of the tank P. After about one second from this the ACS opens the secondary deaeration valve 14 of the tank P. Next, about a second later, the ACS starts the cargo supply valve 5 inside the tank P, opening it for about four seconds, thus allowing the cargo to fill the tank P. After this four second period, the ACS closes the cargo supply valve 5 and opens the P the compressed air supply valve 10. The latter operation allows the compressed air line 11 and through the shut-off valve 6 into the tank P, which causes the cargo to settle through the bottom of the tank into the cargo outlet line 18 and through the control valve 19 into the common cargo line 20 on the deck. to the east to steer to the starboard or port side of the ship using the shut-off valves 21. The elapsed time from the nearly empty, i.e. closed, phase until the tank P is full and compressed air has entered it is seven and a half seconds. As a result, seven and a half seconds are available for the emptying operation and the total time required to complete the cycle is fifteen seconds. The sequence of operations described in connection with tank P also takes place in connection with tank S, however, it is timed by means of ACS so that when tank P is filled, tank S is emptied and a continuous and uninterrupted flow of cargo is achieved. The complete cycle of both tanks takes place at the assumed speed within fifteen seconds, i.e. four times per minute 3, resulting in a pumping speed of about 5565 m per hour.

After the cargo tanks have been emptied, automatic devices are used to shut down the system. Although the pumping tanks are never completely empty during normal use, they are emptied at the end of the pumping operations when the cargo tanks are finally emptied.

This situation in the pumping tanks triggers a detection element 60680 tin B (Figures 4 and 5) at the bottom of each pumping tank. This causes the ACS to close the compressed air supply valve 10 to both pumping tanks and open the original and final outlet valves 14 and 15 for both pumping tanks.

The normal way for supplying and removing compressed air is to use a common air supply and exhaust line 11 passing through the shut-off valve 6 and the inspection pipe 8. However, when handling sludge loads, air is supplied via a shut-off valve 7 near the bottom of the pumping tanks for improved operation. In this case too, the exhaust air passes through the line 11 and the inspection pipe 8.

As described in connection with the basic system, for example, a vacuum of more than 500 mm Hg is applied to the vacuum container V

2 by means of the primary exhaust air and for example a pressure of 0.35 kp / cm is maintained in the tank 32 by means of a pressure control valve 30 in the line 29. From this point on, changes have been made in the treatment of the exhaust air in connection with the barge application compared to the basic system.

The connection to the tank 32 allows exhaust air to pass through the flame shield 33 and onwards through a pressure control valve 34 which reduces the air pressure to 0.05 2 kp / cm before the air continues to line 34L. This line leads to cargo tanks where static pressure increases by about 500 mm Hg , which helps to completely empty cargo tanks and, in the case of thick liquids, further facilitates their removal from the tanks. Furthermore, as described in connection with the basic system, the pressure-vacuum valves limit the air pressure in the tanks to, for example, 0.05 kp / cm. Should the pressure in the tank 32 exceed 0.35 kp / cm, the control valve 30 in the line 29 releases the overpressure through the line 31L to the cleaning tank 31. This tank removes moisture and fine constituents from the exhaust air before it is released into the atmosphere through the flame cover 35. The flame guards 35 60680 and 33 are both designed for easy access, inspection and, if necessary, cleaning. The secondary exhaust air valve 14 opens automatically shortly after the primary exhaust valve 15, and the secondary exhaust air flows through line 14L directly to the purge tank 31, which operates as previously described.

A vacuum can also be created as described in connection with the basic system by passing compressed air directly from line 13 to the jet pump 26 by opening the shut-off valve 17 and passing air through line 27. In addition to the vacuum drives described in connection with the basic system, vacuum cleaning of hold spaces in barges is an important application. The barges in use usually contain 2-10 cm or more of bottom sediment, oil and water.

The previously used method of cleaning carcasses is such that it is usually not performed until the barge is taken for cleaning, where this work involves hazards and difficulties. For example, a man has to go under the double bottoms of a barge at several points with a suction hose. This space is so limited and dangerous that it is uncertain to perform a thorough job.

However, the available vacuum of the present invention, as well as the permanently installed smaller piping system 60, which forms an extension of the line 25L (Figures 2 and 4) to the actual subdivisions of the hull, performs this work easily, thoroughly and without danger. oil in his hold. Even in the event of a cargo leak in the hull of the barges provided by this invention, the handling of such cargo is facilitated, as the holds are clean and dry and the cargo emptying system easily recovers the cargo.

Conventional detrimental consequences of methods used with barges and ships, such as high cost of cleaning cargo tanks, loss of equipment and personnel, empty voyages, and fouling of cargo, are largely eliminated by completely emptying cargo tanks in the manner for which this invention is designed and performed. However, it has been found that some cleaning of cargo tanks is necessary after certain types of cargo have been transported and before other types of cargo are accepted for carriage.

The present invention is well suited for use as an on-board tank cleaning system to solve this problem. The method of cleaning, the type of cleaning agent used, and other details vary from container to container to be cleaned. Whatever method is required, this invention is well suited for use in cleaning cargo containers. After the cargo tanks have been cleaned, the cleaning agent is taken out by means of the pumping tanks and stored either in the cleaning tank 31, in the exhaust air tank 32 or in the vacuum tank V, where it is kept for reuse or other purpose.

Another advantage of keeping three tanks - the cleaning tank 31, the exhaust air tank 32 and the vacuum tank V - on the deck is their use to increase the fuel capacity of the tug. The two vessels may use an average of about 350 tonnes of fuel per voyage, however, the limited draft of the tugboat can sometimes cause a problem. This problem is alleviated by keeping ten to fifteen tons of fuel (or lubricating oil) in three tanks on the deck of each barge. In addition, higher fuel capacity is advantageous when purchasing fuel. Of course, the planning of voyage and fuel use must be such that these three tanks on the deck of each barge are available for the system if desired.

Starting the pumping system of the present invention, assuming that a barge full of a certain type of cargo is in the port on the right side towards the shore for unloading, is as follows. Referring to Figures 2, 3, 4 and 5, all shut-off valves in the system are closed. The base mixer 1, Figure 5, the front side is opened allowing water ballast tank 59 (Figure 5), causing a little increase of the barge etusyväyksessä, wherein the pumppaushuo-located. The cargo valves 3 in all cargo tanks are opened from the deck by using guide wheels 2 'and spindles 2. The shut-off valve 6 in the air supply and discharge line 11 is opened to both pumping tanks. The right-hand shut-off valve 21 in the cargo manifold 20 on the cover is opened to remove the cargo directly in the desired direction. The automatic monitoring system (ACS) is activated by a pushbutton and compressed air enters the air line 13. The system then starts operating automatically. When the front ballast tank 59 is full, the bottom tap 1 closes until the cargo is unloaded. Unlike conventional pumps previously used and potentially malfunctioning discharge valves, which can lead to overpressures if the discharge valve is accidentally or intentionally closed, the pressure generated at an arbitrary point cannot exceed the relatively low supply pumping pressure according to the invention.

Once the pumping operations have been completed, a cleaning device for the pumping system is used. Compressed air is led through the shut-off valve 23 to the cargo manifold 20 on the deck with the shut-off valves 21 closed. The control valves 19 in the cargo discharge lines 18 are kept open, allowing compressed air to completely blow out any cargo residue from the bottom of the discharge lines 18 along line 24L through shut-off valves 24 to line 22L, where air flows out through shut-off valve 22 to final cargo line.

Some currently used barges that handle more than one type of cargo are equipped with two or more diesel engines and pumps. Such multiple devices are unnecessary in connection with barges equipped with the present invention, as the system can be easily and thoroughly cleaned after handling each type of cargo.

The loading of liquid cargoes into currently available barges is usually carried out by means of a loading line permanently mounted on the barge deck, from which the cargo falls freely into the cargo tanks. This poses some hazards, especially when handling flammable or otherwise dangerous loads. In the barges provided with the present invention, the cargo is loaded via lines 20, 18 and FL by means of manual control via shut-off valves 21 and supply valves 3 of individual cargo tanks. No free fall occurs and no loading line on the barge deck is required.

The operation of the present invention is silent and flexible when feeding evenly large amounts of cargo. In addition to the benefits and opportunities already described, barges and ships equipped with this system are more usable and versatile and can be applied to more extensive transport. The efficiency and reliability of the deaeration operation compared to conventional pumping systems with frictional, mechanical and energy losses is clear. Many of the hazards of conventional systems have been eliminated without the emergence of new hazards. Environmental pollution is reduced by the elimination of diesel engine exhaust gases from each barge and by a clean system that also allows for the handling and storage of normal pollutants on board the ship itself.

An example of the various variations that are possible within the scope of the invention is the use of a closed pumping system using an inert pressure medium, such as nitrogen instead of compressed air. Raw-

Claims (7)

1760680 The treatment of oil in oil fields where pressurized natural gas is available can be made even more advantageous by the present invention if this gas is used as a pumping medium before it is generally combusted for use. A system for transferring liquid, sludge or similar fluid from a storage tank (42) to an outlet device (20), the transfer taking place by allowing material to flow from the storage tank (42) through an inlet device (5) alternately to two pump chambers (P, S). to the discharge device (20) by passing the gaseous pressure medium under overpressure from the pressure medium inlet member (10) to a pump chamber (P or S) filled with liquid material, after which the pressure medium in the pump chamber used is completely discharged from the pump chamber (14, 15). , 27, 29), characterized in that a part of the pressure medium to be discharged through the pressure medium removal member is led to the storage tank (42) during emptying of the pump chamber (P or S) to promote the discharge of material from there to the next pump chamber (S or P). A system according to claim 1, characterized in that the gaseous pressure medium is divided in the first part of the emptying stage, in the pressure medium removal member (14, 15, 27, 29) into two streams, one of which is led through a throttle valve (34) to the storage tank (42) and the other is passed to the outside air via a flow resistor (30), for example a pressure control valve which maintains a predetermined pressure, and that the pressure medium at the end of the purge stage is led to the outside air via a second flow path. A system according to claim 2, characterized in that the gaseous pressure medium is allowed to flow, not only to the storage tank (42) itself, but also to the pressure medium storage (32) which is connected to the storage tank. 18 60680 A system according to claim 2 or 3, characterized in that the gaseous pressure medium passes, before it is introduced into the storage tank (42), through a flow resistor having a low value as long as the pressure of the pressure medium in the storage tank (42) is lower than predetermined pressure and which increases to the maximum value when the pressure in the storage tank has risen to a predetermined pressure. System according to at least one of the preceding claims, characterized in that after the overpressure in the pump chamber has been emptied, a vacuum is applied therein, preferably before it is connected to the storage tank, which vacuum is removed at the latest when the pump chamber is filled with material. System according to at least one of Claims 1 to 4, characterized in that the gaseous pressure medium, when discharged directly or indirectly into the outside air, is supplied to a pressure suction device (26) for sucking gaseous pressure medium from the vacuum tank (V) the vacuum in the tank is preferably used, after the overpressure of the pump chamber has been emptied, to set it under vacuum, preferably before it is connected to the storage tank (42), which vacuum is removed at the latest when the pump chamber is filled with material. System according to at least one of Claims 1 to 6, characterized in that the storage tank is a ship's cargo tank and that the common suction line (FL) and outlet line (20) of the pump chambers (P, S) are each connected to a flow tank for conveying or suctioning on board one of the tanks or to remove material from the cargo tank. 19 60680