WO2003077721A1

WO2003077721A1 - Oil delivery and collection system

Info

Publication number: WO2003077721A1
Application number: PCT/IB2003/001709
Authority: WO
Original assignee: Cargill Incorporated
Priority date: 2002-03-20
Filing date: 2003-03-20
Publication date: 2003-09-25
Also published as: GB2386686A; GB0206578D0; AU2003219453A1

Abstract

A cooking oil delivery and collection system for one or more food preparation facilities, e.g. restaurants, comprising, at each food preparation facility, a fresh oil tank (110), a used oil tank (210), pipes (20, 26) for connecting the fresh oil tank ( 110) and the used oil tank (210) to a deep fat fryer (24), a pipe for connecting the fresh oil tank (110) to a port (12) for oil delivery to the fresh oil tank (110) and a pipe for connecting the used oil tank (210) to a port (12) for oil collection from the used oil tank (210), wherein the fresh oil tank (110) has a level sensor (16) for indicating when the level in the fresh oil tank (110) falls below a predetermined level and the used oil tank (210) has a level sensor (18) for indicating when the level in the used oil tank (210) exceeds a predetermined level, the sensors (16, 18) being connected to a telecommunications system for sending signals to a fresh oil delivery company or a used oil collection company to request delivery or collection of oil, respectively. Scheduled deliveries of oil are also provided. A high level sensor (14) is also provided in the fresh oil tank (110), set at a level just above the level corresponding to the normal oil usage for that restaurant in the scheduled delivery period.

Description

Oil Delivery and Collection System

The present invention relates to the delivery and collection of cooking oil from food preparation facilities that use deep fat fryers. The invention provides a system for the delivery of fresh cooking oil to restaurants, the automatic handling of both the fresh oil and the used oil within the restaurant and the collection of used oil from the restaurant, all without the need for any manual handling of the oil.

Food preparation facilities such as restaurants, canteens, pre-packed or pre-cooked food suppliers, e.g. for airlines and shops, and pubs are typically supplied with cooking oil in some kind of packed form (oil packs). The companies involved in the supply and disposal chain for these cooking oils are usually an oil refiner, a packer, a distribution company, a company for collecting the used oil and the packs and finally a company for processing the used oil.

Certain users of cooking oil, however, are concerned about being able to trace where the oil comes from and how it is used after it leaves them. For example, the used oil may be used to make animal feed supplied to, for example, chicken breeders. However, this may be unacceptable for certain animal welfare groups. A more appropriate use might therefore be for making biofuels such as biodiesel. It would therefore be desirable to reduce the number of companies in the supply and disposal chain to simplify and guarantee traceability.

Within a restaurant, for example, it is standard practice for an operative within the restaurant to have to lift and transfer oil packs from an oil pack delivery vehicle into a storage area and then lift them again to carry them to a fryer for emptying into the fryer. Oil in the fryer is then used for cooking.

Over time, the oil level in the fryer will fall since the oil is absorbed into the cooked food. The fryer will therefore need occasional topping up.

The oil in the fryer will also deteriorate over time due to oxidisation and due to it taking on food debris. The cooking oil is therefore filtered to extend its useable life. The filtration can be conducted through a filter either in the fryer or in a stand alone filter device (perhaps connected to the fryer by pipes). However, the oil will eventually deteriorate to a point of non-useability. At this time, the operative will empty the hot oil from the fryer into a receptacle (sometimes the old packs) and then the dirty used oil is finally stored until a collection company can pick up the receptacles. The fryer is emptied hot to avoid solidification.

The fresh oil packs or the used oil receptacles are often heavy. Therefore the filling, topping up and removal of oil from the fryer often leads to physical strain to the operative lifting the heavy loads. Also there is the risk of potential burns from handling hot frying oil. Further there is the risk of the cook, or other employees or individuals in the cooking area of restaurant, slipping on spilt oil or tripping over the packs or receptacles. It would therefore be desirable to provide a new system for filling, topping up and removal of cooking oil from a fryer. It would also be desirable to automate the system from the supply of the fresh oil to the disposal of the used oil within a restaurant.

US Patent US-A-5 ,249,511 discloses a system for semi-automating the transfer of oil from a storage tank in a restaurant to a deep fat fryer. In this system, a hose is provided extending from a tank for delivering the oil from the tank to the fryer via a pump. By means of this, oil can be pumped from the tank, through the hose, to a nozzle at the end of the pipe. The nozzle is held above the fryer by an individual for filling up the fryer. Topping up, also, will be performed as and when required with the nozzle.

For pumping oil out of the fryer, the same nozzle can be inserted into the oil in the fryer and, by reversing the flow direction for the oil, the oil will be removed from the fryer.

US Patent US-A-5,964,258 discloses a system for connecting an oil tanker to a fresh oil tank and to a used oil tank in a restaurant for delivery or collection of oil to or from the fresh oil tank and the used oil tank. The system uses hoses from the tanker that connect to ports on an external wall of a restaurant, with pipes inside the restaurant connecting the ports to a fresh oil tank and a used oil tank. The use of these prior art systems still requires effort on behalf of the restaurant manager or individual operatives within the restaurant. For example, the manager needs to ensure that fresh oil is always available so will need to monitor the usage of the oil in the restaurant and arrange for delivery of oil for the fresh oil tank as and when required. The manager will also need to ensure that used oil is collected before the used oil tank overflows. Additionally, an operative has to handle the nozzle and therefore runs the risk of being burnt by the hot oil when inserting the nozzle into the fryer, or spilling oil either when filling or emptying the fryer.

It would be desirable, therefore, to provide a system by means of which both fresh and used frying oil can be supplied and removed to a food preparation facility with the minimum amount of handling and with no manual intervention, i.e. so that the manager or owner of the food preparation facility no longer has to order or arrange transportation of either fresh or used oil to or from the food preparation facility, or to or from a plurality of food preparation facilities in a chain of food preparation facilities. Such a system would provide the added benefits of a safer and cleaner working environment in the food preparation facility.

It would also be desirable to provide a system by means of which fresh oil can be supplied as infrequently as possible so that the fresh oil tank is nearly empty before fresh oil is added thereto. By doing this a greater percentage of fresh oil, relative to the not-so-fresh oil will be present in the fresh oil tank.

According to a first aspect of the present invention, there is provided a cooking oil delivery and collection system comprising, at a site of a food preparation facility, a fresh oil tank, a used oil tank, a vent for connecting the fresh oil tank to a deep fat fryer, a vent for connecting the used oil tank to the deep fat fryer, a vent for connecting the fresh oil tank to a port for oil delivery to the fresh oil tank and a vent for connecting the used oil tank to a port for oil collection from the used oil tank, wherein the fresh oil tank has a level sensor for indicating when the level in the fresh oil tank falls below a predetermined level and the used oil tank has a level sensor for indicating when the level in the used oil tank exceeds a predetermined level, the sensors being connected to a telecommunications system for sending signals to a fresh oil delivery company or a used oil collection company to request delivery or collection of oil, respectively.

Preferably, various pipes or pipework connect the vents to the ports or to the deep fat fryer.

Preferably the fresh oil tank further comprises a high level sensor for indicating when the level in the fresh oil tank exceeds a predetermined level, the sensor being connectable to a tanker delivering the fresh oil.

According to a second aspect of the present invention there is proved a cooking oil delivery system for a food preparation facility, the system comprising a fresh oil tank, a vent for filling the tank with fresh oil, a high level sensor and a sensor for measuring use of oil from the tank, wherein the high level sensor is set to provide an indication when a predetermined level is reached, the predetermined level being just above the level reached in the tank by placing in the tank, when empty, the average volume of oil used by the food preparation facility in a predetermined time period, the predetermined time period corresponding to a period between scheduled deliveries of oil to that food preparation facility.

The features of the first and second aspects can be incorporated together into a single system.

Preferably the two ports are provided externally of the food preparation facility for delivery and collection of oil by a tanker.

Preferably the system includes a tanker comprising a tank for fresh oil, a tank for used oil and pipes for connecting to the respective ports.

Preferably the tanks on the tanker are arranged such that they balance the oil load on the tanker both when loaded with fresh oil and when loaded with used oil. Preferably a single tanker carries enough fresh oil and has enough space for used oil in its tanks to deliver and collect oil to and from a plurality of food preparation facilities without returning to its depot.

Most food preparation facilities, in particular restaurants, have a fairly constant rate of oil usage. Therefore, preferably oil delivery times and oil collection times are scheduled at appropriate intervals so that delivery or collection occurs at times at times at which the fresh oil tank would be expected to be nearly empty or the used oil tank would be expected to be full. This enables an oil delivery company or an oil collection company to arrange efficient delivery or collection circuits between multiple food preparation facilities. The sensors provide a safeguard should either tank be used more than expected, without any need for manual inspection of the tanks to monitor this.

Preferably the system comprises flow meters for measuring the quantity of oil delivered or the quantity of oil collected, and a report generator for producing a delivery or collection note for posting in the food preparation facility. This data may also be logged for future reference. The report generator may be a printer.

Preferably the systems comprise flow meters for determining the amount of oil used.

It should be noted that the amount of used oil returning to the used oil tank from the deep fat fryer is not the same as the amount of oil supplied to the deep fat fryer, or the amount of oil used by the food preparation facility. This is because food will generally absorb some of the oil as it is cooked. However, it may be approximately proportionate thereto.

Preferably the system comprises a plurality of food preparation facilities, each having a fresh oil tank, a used oil tank, pipes or pipework for connecting the tanks to ports and deep fat fryers, and sensors as defined above, each food preparation facility having matching ports for connecting to a single tanker.

The sensors may be fluid sensors (e.g. fluid level probe sensors) or weight sensors. They may be direct, i.e. in or on the tank, or indirect, i.e. calculated; by measuring the flow from the tanker and the usage of oil, by measuring flow into and out of the tanks, or by weighing the tanks (either in the food preparation facility or on the tanker, or both), the quantity of oil in, having been delivered to, or having been collected from each tank, at any time, can be calculated. Other methods of sensing may also be used. Preferably oil in each food preparation facility can be delivered to an oil vat of a fryer, removed from the oil vat of the fryer or filtered at the fryer by activation of a control signal at a system control box provided at the fryer, for example by the press of a button. The valves and the pumps may alternatively be manually operated to control oil flow between the tanks, the fryer and the filtration system.

The present invention further provides a method of arranging the delivery of oil to a food preparation facility, the food preparation facility comprising a fresh oil tank, a high level sensor and a sensor for measuring use of oil from the tank, the method comprising scheduling regular oil deliveries at predetermined intervals and setting the high level sensor to provide an indication when a predetermined level of oil in the tank is reached, the predetermined level being just above the level reached in the tank by placing in the tank, when empty, the average volume of oil used by the food preparation facility in the predetermined interval, and filling the tank at each delivery to that predetermined level.

The present invention further provides a method of arranging oil delivery and collection at a food preparation facility, comprising providing at a food preparation facility a fresh oil tank, a used oil tank, a vent for connecting the fresh oil tank to a port for oil delivery to the fresh oil tank and a vent for connecting the used oil tank to a port for oil collection from the used oil tank, providing for the fresh oil tank a level sensor for indicating when the level in the fresh oil tank falls below a predetermined level and providing for the used oil tank a level sensor for indicating when the level in the used oil tank exceeds a predetermined level, and connecting the sensors to a telecommunications system for sending signals to a fresh oil delivery company or a used oil collection company to request delivery or collection of oil, respectively, when either sensor provides an indication that its respective level has been reached.

Preferably, oil delivery and oil collection occurs at the same time.

Preferably the tanker delivers and collects oil to and from ten, twenty or thirty food preparation facilities between trips to its depot, and most preferably at least twenty food preparation facilities. Deliveries may be scheduled at appropriate intervals. The intervals may be seven, fourteen or twenty one days. With this system in place, the fresh oil tank should nearly be empty every time it is filled up.

To quantify the average volume of oil used by the food preparation facility, it may be necessary to check the level of the fresh oil tank at the time of delivery. A low level sensor in the tank could be used for this purpose. Alternatively the use in the food preparation facility may be metered, the meter being connected to the port so that it can be read by the tanker driver. It may alternatively be connected to a telecommunication system for sending data to the oil delivery company.

The present invention also provides a system in which the used oil tank is the only tank having a level sensor. The sensor is for providing an indication of when that tank is full. This alone could indicate that a refill of the fresh oil tank is necessary. If the used oil tank is full, the fresh oil tank is most probably empty, or nearly empty. The quantity of oil in the system is substantially constant, or able to be estimated given the rate of absorption of oil into food.

Preferably the used oil tank is substantially the same or a slightly smaller size than the fresh oil tank.

The present invention, as described above, enables a food preparation facility to arrange delivery and collection of its cooking oil from an oil delivery company or an oil collection company without any manual interaction by the food preparation facility owner or its employees, i.e. automatically.

The present invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic of a tanker, meters and printing means for delivering or the collection of oil to or from a restaurant fitted with the present invention.

Figure 2 shows a schematic of the system of the present invention in a first type of restaurant; and

Figure 3 shows a schematic of the system of the present invention in a second type of restaurant. A system in accordance with both aspects of the present invention is shown in the Figures and comprises five main elements:

a) a storage tank 10 having two parts: a first tank 110 for fresh oil and an second tank 210 for used oil; level sensors 14, 16, 18 are provided for these tanks as described below (see Figures 2 and 3) (for standard retail applications, e.g. in restaurants, this tank 10 will be approximately 1000mm x 900mm x 2000 mm tall); b) a tanker 100 for delivering fresh oil, for example tropical refined oils, and collecting used oil from the tanks 110, 210; c) an intake/outlet box or port 12 situated on an outside wall of the restaurant for use as a connection point between the tanker and the tanks (110, 210); d) oil pumps and associated pipework; and e) a system control box at the frying station.

Referring now to Figure 1, there is shown a tanker 100. However, it should be noted that other delivery vehicles could be used as well.

Fresh oil for the restaurant is delivered, and used oil is collected, by the tanker 100. The deliveries and collections of oil are made together, at regular intervals, as agreed between the restaurant management and the oil supplier.

The amount of oil delivered will be set such that, apart from a small contingency amount, all the oil will be used up before the next delivery. All the used oil present in the used oil tank 210 will be collected when a delivery is made. A high level probe sensor 14 in the fresh oil tank 110 will be set at the appropriate level to warn against overfilling of the fresh oil tank 110.

The delivery driver will have access to the port 12 on the outside wall of the restaurant. The port 12 is kept locked in order to maintain the food safety integrity of the system. Only the driver and the restaurant manager/owner will have a key to the port 12. Backup keys may be held elsewhere.

When a delivery/collection is made, the driver will connect a delivery pipe 102 and a collection pipe 104 to a delivery point and a collection point within the port 12. Couplings between the pipes 102, 104 of the tanker 100 and the port 12 are preferably of a quick- release type (not shown) and have built in shut off valves (not shown) so that the pipes 102, 104 are sealed once the connection is broken.

The fresh and used oil couplings are different sizes thus preventing the driver from incorrectly connecting, i.e. cross connecting, the pipes 102, 104.

Using pumps built into the tanker 100, used oil is sucked out of the used oil tank 210 in the restaurant into a collection tank 106 of the tanker 100. At the same time, fresh oil is pumped from the tanker 100 into the fresh oil tank 110 of the tank 10 in the restaurant. The tanker 100 will be connected to the high level sensor in the fresh oil tank. This connection provides an automated cut-off signal from the sensor for stopping oil delivery when the fresh oil tank 110 is appropriately filled.

The fresh oil comes from supply tanks 108 either side of the collection tank, the two supply tanks 108 being hydrostatically connected to each other so that the levels in the tanks 108 remain balanced despite the levels of the oil going down. The collection tank 106 may also be provided as a pair of interconnected tanks.

The tanker 100 is fitted with flow meters 112 to measure the amount of oil fresh oil delivered and the amount of used oil collected. The flow meters are connected to a small microprocessor and the delivery/collection data is logged. At the end of the operation a delivery/collection note is printed and left for the attention of the restaurant management.

The fresh oil flow meter may be used as a backup for the automatic delivery cut-off provided by the high level sensor in the fresh oil tank 100, or as an alternative therefor. This should prevent any overfilling of the tank 110.

The delivery may take place when the restaurant is closed, whereupon the delivery/collection note can be posted at the time of delivery, e.g. into a letter box or under the door of the restaurant. Alternatively, the metering may be done at the port 12, with the delivery/collection note being posted within the restaurant for review by the management. Referring now to Figures 2 and 3, the mechanisms within the restaurant will be described. A fresh oil tank 110 and a used oil tank 210 are provided as a single unit. These tanks can be filled and emptied, respectively, as described above. Fresh oil in the restaurant is used from the fresh oil tank 110 for cooking in vats 24 of deep fat fryers. Once used, the oil is pumped from the vats 24 to the used oil tanlc 210 for removal as described above. The delivery and collection of oil is scheduled as described above to optimise the amount of oil delivered and collected on each trip by the tanker 100.

Although this application refers to deep fat fryers, users of bulk cooking oil may have other oil operated cooking stations for which this invention could be applied.

Automatic safeguards are built in to the tanks 110, 210 to ensure that the restaurant neither runs out of fresh oil nor overfills with used oil between the scheduled deliveries and collections. The fresh oil tanlc 110 is built with a high level probe sensor 14 and low level probe sensor 16. A high level probe sensor 18 is also provided for the used oil tank 210.

The fresh oil high level sensor 14 is set to provide a warning at a level that is determined by the normal or average quantity of oil used by the restaurant in the period between deliveries. This is so that, when a delivery is made, there will be no oil left in the tank (except for a small contingency supply). This ensures that fresh oil is not put upon large quantities of older oil. To do that would compromise the quality of the oil in the fresh oil tank 110. The level is set just above the level to which the average quantity used in the period between deliveries would reach, if put into an empty tank. The slight distance above the level defined above gives a contingency supply of perhaps a day's use that will be in the tank at the time that the sensor provides its warning.

As discussed above, the high level sensor is also connected to the port 12 so that it can be connected to the control system of the tanker 100. This is so that it can send a signal to the tanker 100 once the tank has been filled to the desired level so that the tanker can stop the pump. This may alternatively be done on a fixed delivery basis, i.e. a set weight or a set volume of cooking oil may be delivered. The low level sensor 16 in the fresh oil tank 110 is connected by a telephone line to a distribution centre of the oil supply company. Should the level of fresh oil ever fall too low, i.e. into the contingency supply, then a warning message will automatically be sent down the telephone line to the distribution centre. If a scheduled delivery is not due to be made within an acceptable timeframe, i.e. before the fresh oil supply would run out, an additional delivery/collection will automatically be arranged. This timeframe would be one day if the contingency supply was one day's usage.

The high level probe sensor 18 in the used oil tank 210 is also connected by a telephone line to the distribution centre. If the used oil tank 210 gets too full, then, likewise, a delivery/collection will automatically be arranged. The high level sensor should be set just below full to provide a similar contingency amount of space in the tank 210 to that of the fresh oil tank 110.

Figures 2 and 3 show a series of fresh oil pipelines 20 and a distribution pump 22 installed in the restaurant to enable distribution of fresh oil to a vat 24 of one or more fryer. A series of used oil pipelines 26 and a removal pump 28 are also installed in the restaurant to remove used oil from the fryer vat or vats 24 to move it to the used oil tank 210, as required.

Referring now to Figure 2, there is shown a system in accordance with the present invention for supplying oil to two fryer vats 24. The fryer vats 24 each have a built in filter system 40. The filter systems 40 each comprise two three-way valves 42, 44, the removal pump 28 and a filter 46.

The three way valves 42, 44 are electrically operated valves and can be set to a number of states in response to a control signal. The state is chosen by an operative on a control panel (not shown) by pressing buttons.

For cooking with the oil in the vat, a first button is pressed. This closes all valves and turns off all pumps for that vat. For filtering the oil in a vat 24, a second button is pressed. This turns off the distribution pump 22, if running, and turns on the removal pump 28. Further, the control mechanism operates the valves 42, 44 to connect intake and discharge lines of the vat 24 in such a way that the oil in the vat 24 circulates around the filter system 40, i.e. from the vat 24, through the filter 46, through the removal pump 28, through a first of the three way valves 42, through the second of the three way valves 44 and back into the vat 24. The second vat's filter system operates in much the same way in response to a button on a separate control panel.

To bring fresh oil into the fry vat, a further button (not shown) on the control panel (not shown) is pressed which will reset the valves, start the fresh oil pump 22 and stop the removal pump. The first valve 42 will also be closed so that the filter will not have oil passing through it. The second valve will also be set to allow oil from the fresh oil pipeline 20 to pass therethrough into the vat 24. The vat 24 will thereby fill with oil without any handling of oil by the operative.

To discharged oil from the vat 24 to the used oil tank 210, another button (not shown) will be pressed. This will further reset the valves and start the removal pump 28. The second valve will be closed and the first valve will connect with the used oil pipeline 26.

It will be appreciated from the above that there will be no handling of the oil at all by operatives using this system.

A logic control circuit can be provided to manage the various valves and pumps. However, in place of the logic control circuit, or the buttons, the valves may be operated manually. The opening and closing of the valves may be used to trigger, via a logic control circuit, the starting or stopping of the appropriate pumps automatically. However, the pumps may also be manually controlled, e.g. by on/off switches.

The controls (e.g. the control panel and buttons) for the system are situated at the fry station. Preferably a set of buttons or controls is provided at each fry station. This is so that the operative can easily monitor the filling, the filtering and the discharge of oil. The operative can view the operation as it is happening and shut of the pumps when required. Referring now to Figure 3, there is shown a system in accordance with the present invention for supplying oil to just one fryer vat 24. The fryer vat 24 in this embodiment does not have a built-in filtration system. Further, the fresh oil pipeline 20 only carries oil to points close to the vat 24.

At the end of the pipeline 20 there is a section of flexible pipe 30, at the end of which is provided an electrically operated valve 32. The flexible pipe 30 also has a handle 34 at the end of it. The handle 34 has a control button (not shown) for operating the valve 32. The operative is able to take the handle 34 of the flexible pipe 30, and by pressing the button 34, he can open the valve 32. The fresh oil pump 22 will simultaneously start to operate so that the operative can fill the vat 24 with the oil coming out the handle 34 through the valve 32.

Once the oil in the vat 24 has been used, the used oil from the vat 24 can be discarded into a stand alone filter machine 36, e.g. by draining the oil out of the bottom of the vat 24, for cleaning and possibly, thereafter, returned to the vat 24. However, if it is considered no longer to be of useable quality, then the operative will discharge the oil through a discharge valve 38 on the filter system, and, using the removal pump 28, pump the used oil to the used oil tank 210 through the used oil pipeline 26.

It should be noted that the present invention is particularly suited for retail applications, for example, restaurants. Such applications generally use refined vegetable oils as their cooking oil. The oil may be a partially hydrogenated rapeseed oil with DMPS added as an anti-foaming agent. The anti-foaming agent prevents foaming during the frying operation.

The present invention provides the following advantages over the prior art:

1. Improved oil quality in the food preparation facility compared to previous semi- automated systems. The high level of the fresh oil tank can be set for the needs of individual food preparation facilities such that the quality of the oil can always be guaranteed irrespective of the food preparation facility's oil turnover.

2. Reduced management time. The low level sensor 16 of the fresh oil tank 110 and the high level sensor 18 on the used oil tank 210 are connected to a telecommunications system for sending low or high level warnings to the distribution centre to guarantee that the food preparation facility will never run out of fresh oil and to guarantee that the used oil tank 210 will never overflow, without the need for user intervention or monitoring. 3. Due to increased delivery amounts (bulk tanks, multiple food preparation facilities), it will be cost effective to obtain oil direct from the refinery, i.e. without an intermediate storage or distribution centre. This reduces the possibility of oil quality deterioration through delay in the supply chain, and also the complete refining and supply system becomes the responsibility of one company (the refiner) such that the oil quality can be guaranteed at source and up to the point of delivery at the fryer.

4. Because the used oil can be collected from a large number of similar food preparation facility on each tanker journey, the quality of the collected oil is very consistent. It therefore has enhanced value in that the impurities will be less varied.

5. The reduced number of companies involved in the supply and disposal chain for the oil provides a simplified traceability for the oil. This is important, for example, for users who have specific requirements as to the usage of the used oil after the oil has been collected.

The present invention has been described above purely by way of example. Modifications in detail may be made to the invention as defined in the claims appended hereto.

Claims

1. A cooking oil delivery and collection system comprising, at a site of a food preparation facility, a fresh oil tank, a used oil tank, a vent for connecting the fresh oil tank to a deep fat fryer, a vent for connecting the used oil tank to the deep fat fryer, a vent for connecting the fresh oil tank to a port for oil delivery to the fresh oil tank and a vent for connecting the used oil tank to a port for oil collection from the used oil tank, wherein the fresh oil tank has a level sensor for indicating when the level in the fresh oil tank falls below a predetermined level and the used oil tank has a level sensor for indicating when the level in the used oil tank exceeds a predetermined level, the sensors being connected to a telecommunications system for sending signals to a fresh oil delivery company or a used oil collection company to request delivery or collection of oil, respectively.

2. The system of claim 1, wherein the fresh oil tank further comprises a high level sensor for indicating when the level in the fresh oil tank exceeds a predetermined level, the sensor being connectable to a tanker delivering the fresh oil.

3. A cooking oil delivery system for a food preparation facility, the system comprising a fresh oil tank, a vent for filling the tank with fresh oil, a high level sensor and a sensor for measuring use of oil from the tank, wherein the high level sensor is set to provide an indication when a predetermined level in the tank is reached, the predetermined level being just above the level reached in the tank by placing in the tank, when empty, the average volume of oil used by the food preparation facility in a predetermined time period, the predetermined time period corresponding to a period between scheduled deliveries of oil to that food preparation facility.

4. The system of claim 3 additionally comprising the features of claim 1.

5. The system of claim 3, further comprising a used oil tank, a vent for connecting the fresh oil tank to a port for oil delivery to the fresh oil tank and a vent for connecting the used oil tank to a port for oil collection from the used oil tank.

6. The system of claim 4 or 5, wherein the two ports are provided externally of the food preparation facility for delivery and collection of oil by a tanker.

7. The system of claim 6, further comprising a tanker having a tank for fresh oil and a tank for used oil and pipes for connecting the tanker's tanks to the respective ports.

8. The system of claim 7, comprising a plurality of food preparation facilities, wherein the tanker carries enough fresh oil and has enough space for used oil in its tanks to deliver oil to and to collect oil from the plurality of food preparation facilities without returning to its depot.

9. The system of any one of claims 1, 2 or 4 to 8, comprising flow meters for measuring the quantity of oil delivered or the quantity of oil collected and a report generator for producing a delivery or collection note for posting in the food preparation facility.

10. The system of any one of the preceding claims, comprising a plurality of food preparation facilities, each having a fresh oil tank connected to a port and a used oil tank connected to a port, each food preparation facility having matching ports, the ports being for connecting to a single tanker for delivering oil to and for collecting oil from the respective tanks.

11. The system of any one of the preceding claims, wherein oil from the fresh oil tank can be delivered to an oil vat of a fryer, removed from the oil vat of the fryer or filtered at a fryer by activation of a control signal at a system control box provided at the fryer.

12. The system of any one of the preceding claims, wherein one or each sensor is a weight sensor.

13. The system of any one of claims 1 to 11, wherein one or each sensor is a fluid level probe sensor.

14. A method of arranging the delivery of oil to a food preparation facility, the food preparation facility comprising a fresh oil tank, a high level sensor and a sensor for measuring use of oil from the tank, the method comprising scheduling regular oil deliveries at predetermined intervals and setting the high level sensor to provide an indication when a predetermined level of oil in the tank is reached, the predetermined level being just above the level reached in the tank by placing in the tank, when empty, the average volume of oil used by the food preparation facility in the predetermined interval, and filling the tank at each delivery to that predetermined level.

15. The method of claim 14, wherein the food preparation facility further comprises a used oil tank.

16. A method of arranging oil delivery and collection at a food preparation facility, comprising providing at a food preparation facility a fresh oil tank, a used oil tank, a vent for connecting the fresh oil tank to a port for oil delivery to the fresh oil tank and a vent for connecting the used oil tank to a port for oil collection from the used oil tank, providing for the fresh oil tank a level sensor for indicating when the level in the fresh oil tank falls below a predetermined level and providing for the used oil tank a level sensor for indicating when the level in the used oil tank exceeds a predetermined level, and connecting the sensors to a telecommunications system for sending signals to a fresh oil delivery company or a used oil collection company to request delivery or collection of oil, respectively, when either sensor provides an indication that its respective level has been reached.

17. The method of claim 16, comprising scheduling regular oil deliveries at predetermined intervals to the food preparation facility and scheduling additional deliveries or collections when either of the sensors provide an indication that its respective level has been reached.

18. The method of claim 15 or claim 17, wherein a tanker is scheduled to deliver oil to and to collect oil from at least twenty food preparation facilities between trips to its depot.

19. The method of any one of claims 15 to 18, wherein oil delivery and oil collection occurs at the same time.

20. The method of any one of claims 14 to 19, wherein oil delivery times are scheduled at appropriate intervals so that delivery occurs at times at which the fresh oil tank would be expected to be nearly empty.

21. The method of claim 20, wherein the intervals are fourteen days.

22. An oil delivery and collection system substantially as hereinbefore described with reference to Figures 1 and 2.

23. An oil delivery and collection system substantially as hereinbefore described with reference to Figures 1 and 3.

24. A method of arranging oil delivery and oil collection substantially as hereinbefore described with reference to the accompanying drawings.