SYSTEM FOR DETECTING AND RECORDING DISCHARGES OF WASTE HYDROCARBONS OF A SHIP

OBJECT OF THE INVENTION

The present invention relates to a system for detecting discharges of waste hydrocarbons of a ship, applicable for small, medium and large ships as well as oil tankers, allowing a reliable and accurate knowledge of the discharges of waste hydrocarbons of ships whether at sea or in port areas, all of this based on level gauges and a multiparameter recording station in combination with computerized management means established in ports.

The object of the invention is to provide a system that allows port authorities or other competent official organisms to detect in real time any irregular dumping performed during the operation of a ship, whether these are oleous or waste hydrocarbons and cleaning residues from crude oil tanks provided in oil tankers.

BACKGROUND OF THE INVENTION

It is known that ships in general generate waste or oleous hydrocarbons, while oil tankers in addition generate residues in crude oil stowage which comprise an mixture of hydrocarbons, detergents and water and are stored in sludge tanks provided in bilges for discharge in port by the competent authorized organism.

Waste hydrocarbons are also stored in the bilges of ships, so that these contain waste water and oleous hydrocarbons which float on the water to form a top layer with a thickness that depends on the volume of such hydrocarbons.

Said mixed oleous products are suctioned by a pump which separated the oleous hydrocarbons from the water, which is purified to contain a minimal amount of allowed parts per million, with the water discharged to the sea through the ship outlet or discharge pipes. The remaining oleous waste hydrocarbons are stored in a tank for later controlled discharge on land by the authorized company in charge of issuing international certificates for controlling discharged volumes of these products or waste oleous hydrocarbons in port.

Both when extracting waste oleous hydrocarbons or when incorporating new lubrication oil an entry must be made in the "Hydrocarbon Log Book", which includes data corresponding to the number of liters of waste hydrocarbons extracted from the ship, date of the extraction, port of extraction, seal of the corresponding port authority, etc. The same is true for the oil which is incorporated to replace waste oil, so that the log book in question is meant to control the discharge of oleous pollutants in order to prevent this discharge from being dumped at sea in an uncontrolled manner.

However, the accuracy of the data recorded in the book depends on the measurement devices present in the storage tanks and bilges for these products or waste hydrocarbons, which accuracy is generally quite low.

If this is added to the fact that the costs of companies in charge of extracting the oleous waste hydrocarbons or products are high, it is common for part of the load of tanks or bilges to be irregularly dumped at sea before arriving at the port, and due to the high traffic of ships the total volume of these oleous waste products dumped in the sea is currently worryingly large.

In any event, there exists an International Convention approved by the International Maritime Organization meant to control and prevent pollution from ships, in which limits are defined for each maritime area regarding the amount of hydrocarbons that can be dumped at sea during ordinary operations, strictly forbidding discharge of these products in certain areas. Although the enforcement of this convention is quite strict, the fact is that the only controls available to the authorities of each country regarding elimination of waste oleous products or hydrocarbons are the following:

• 1. The "Hydrocarbon Log Book", in which the machinist or competent authority records extraction data for these pollutants and the lubrication oil load, as the amounts eliminated and loaded should be similar. However, this data is inaccurate as the waste hydrocarbon bilges also contain residual water deposited from water pump leaks, purges of hydraulic systems, cleaning of the machine room, etc.
• 2. Monitoring from the air to locate and penalize ships which perform illegal dumping at sea.

As described above these controls are insufficient, and in fact the amount of waste hydrocarbons dumped directly into the sea is currently significant, as is its consequence, that is, marine pollution.

A similar problem is found with tankers which transport crude oil or hydrocarbons, as these ships must clean their storage tanks periodically, or each time they are emptied.

Specifically, for small and medium sized ships discharge of waste oleous hydrocarbons is performed by operating a helical pump which suctions the product from the bilge and sends it to a centrifuge meant to separate water from hydrocarbons, so that this separator detects a minimal number of parts per million of oleous products, performs the separation and the water is discharged to the sea through an electro-valve, while a second electro-valve opens to allow the hydrocarbons to pass to a storage collection tank of the ship in its bilge.

If the separator finds that the product does not comply with the minimum requirements for oleous products the first electro-valve opens and the entire product is dumped into the sea.

Likewise, oleous waste resulting from cleaning crude oil stowage tanks of oil tankers are suctioned by a pump and stored in a sludge tank for later discharge at port.

DESCRIPTION OF THE INVENTION

The system taught is designed to allow authorities and competent organisms to control discharge of waste hydrocarbons, both for hydrocarbons stored in the bilge of any ship and those in the sludge tank of oil tankers.

More specifically, the system for detecting and recording discharges object of the invention is based on two floating probes placed inside the bilge, one of which floats permanently on the upper layer of oleous hydrocarbons while the other floats on the waste water layer, thereby determining the lower level of said hydrocarbons which float on the water.

Additionally, the system can optionally incorporate a third probe used to detect the level of oleous hydrocarbons stored in the collection tank for these hydrocarbons after they are separated from the waste water dumped into the sea.

These probes detect the aforementioned levels, which are then entered in a "black box" or multiparameter recording station, which records and stores them together with the corresponding date and time, including any level changes which imply variations in the volume of waste products.

Detecting and recording discharges of sludge from cleaning crude oil tanks in tankers is achieved by placing at the union of the conducts arriving from said crude oil tanks and before the sludge tank where said cleaning residues are stored a flow meter associated to the corresponding suction pump for these residues, so that the values obtained by said flow meter are recorded in the "black box" or multiparameter recording station together with the date and time of the measurement.

Thus, the competent port authority can extract the data from such a multiparameter recording station of any ship and compare them to the entries in the hydrocarbon log book of each ship, in order to discover any uncontrolled dumping, such that the data stored in the multiparameter recording station are collected in the mouth of the mooring of the ship at each port and transmitted by radio to the port captaincy, thereby obtaining information when each ship arrives of the data in the multiparameter recording station, which data can be later checked by the port authority requesting the Hydrocarbon Log Book from the corresponding person on the ship.

Finally, in order to prevent claims of a ship power outage preventing said data control and recording elements from having operating during certain periods, the system is complemented by emergency power means integrated in the multiparameter recording station to ensure a continuous operation for 24 hours.

DESCRIPTION OF THE DRAWINGS

The present description is complemented by a set of drawings of a preferred embodiment of the invention, which will make clearer the characteristics of the invention and where for purposes of illustration only and in a non-limiting sense the following is shown:

• Figure 1 shows a schematic representation of the invention applied to the bilge of a ship.
• Figure 2 shows another schematic representation of the part of the system which includes a flow meter meant to measure the waste originated in cleaning the crude oil tanks of an oil tanker.
• Figure 3 shows a block diagram of the system for transmitting the data from the multiparameter recording box installed on the ship to the captaincy of a port, through the port mouth.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the above described figures the system of the invention, applicable to the bilge (1) of a ship containing a volume of waste water (2) and a volume of oleous or waste hydrocarbons (3), forming a layer that floats on said volume of waste water (2), comprises as is conventional a helical pump (4) for suctioning the waste product contained in the bilge (1), so that in combination with this pump (4) is provided a separator (5) to separate the waste water from waste hydrocarbons, so that said water is sent by an elector-valve (6) and through a pipe (7) directly to the sea, while waste hydrocarbons obtained in the separator (5) are sent by electro-valve (8) through pipe (9) to a storage tank (10), also communicated to the outside by a pipe (11) with an interposed valve (12).

Based on these characteristics, one of the basic novelties of the system of the invention consists of including a pair of floating probes (13-14), the first of which floats on the layer (3) of waste hydrocarbons which floats on the volume of the waste water layer (2), with this probe (13) defining a detector for the top level of this layer of waste hydrocarbons (3), while the probe (14) floats on the layer of waste water (2), defining a detector for the bottom level of the aforementioned layer (3) of waste hydrocarbons.

These sensors (13-14) with the appropriate technology allow to detect any decrease in the levels of the bilge (1) by determining a decrease in the level of the hydrocarbon layer (3) in a certain period, for which the data acquired by said probes (13-14) are sent to a black box or multiparameter recording station (15) belonging to the ship itself, as are data from a third level probe (16) provided inside the tank (10) for storing waste hydrocarbons obtained at the separator (5).

In this manner two values for the volume of waste hydrocarbons are obtained, an accumulated one for waste hydrocarbons extracted from the bilge (1) and one corresponding to the waste hydrocarbons stored in the tank (10) .

Obviously, the value of these two parameters must agree at all times and must lie within a tolerance range which is not greater than the uncertainty in the entire measurement chain; otherwise it would be apparent that an irregular extraction or dumping of waste hydrocarbon has been performed, which would be recorded in the multiparameter recording station (15) along with the date, time and variation in the hourly interval of the volume of hydrocarbons stored in bilge (1) and tank (10) and the corresponding diagnostic.

Additionally, to detect and record possible dumping of sludge from cleaning of crude oil tanks (17) of a cargo ship or oil tanker, in its corresponding bilge (1) a flow meter (18) has been provided in the pipe (19) at which meet all pipes from the various oil tanks (17), with this flow meter (18) being associated to the corresponding extraction pump (20) that suctions the residues resulting from cleaning said tanks (17), measuring both the volume and flow extracted from any of these tanks (17) so that the data is sent to the black box or multiparameter recording station (15), where they are stored in the same manner as with the data obtained from the probes (13-14-16). These residues resulting from cleaning the tanks (17) are sent to a sludge tank (21) by a discharge pipe (22) with an interposed valve (23).

Obviously both the data obtained from the probes (13-14-16) and that obtained from the flow meter (18) are stored with the corresponding date and time so that at the end of the ship's day run said multiparameter recording station (15) provides the competent and authorized authority with the total volume of hydrocarbons (3) extracted from the tank (10) during the day run of the corresponding ship, which amounts must agree with those stored in the corresponding bilge (1) or in tanks (10); otherwise, as explained above, an illegal dumping must have taken place (Fig. 1).

In oil tankers the residues from cleaning the tanks (17) as measured by the flow meter (18) must agree with the amount stored in the sludge tank(s) (21) (Fig. 2).

Figure 3 shows the schematic representation of the data transmission process from the multiparameter recording station (15) of the ship (24), which takes place by radio using the radio (25) of the ship (24), emitting the data from the multiparameter recording station (15), which are then collected by a radio emitter (26) provided in the port mouth (27), with a communications control block (28) associated to said radio emitter (26), which using a modem (29) and via radio sends the data to another modem (30) of the port captaincy (31) connected to a computer (31) and a printer (32), so that as soon as the ship docks in port the captaincy will know the data stored in the multiparameter recording station (15), which data can be later checked by the corresponding port authority by demanding the "Hydrocarbon Log Book" from the authority of the ship (24).

In the event of a power failure, whether accidental or intentional, the multiparameter recording station (15) incorporates, integrated in it, an emergency system which ensures its operation for a minimum period of 24 hours, with this status recorded hourly until the conventional power supply is restored.