GB2404913A

GB2404913A - A liquid delivery system having a wet line and a dry line hose

Info

Publication number: GB2404913A
Application number: GB0312953A
Authority: GB
Inventors: Johann Heidt
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-06-05
Filing date: 2003-06-05
Publication date: 2005-02-16
Anticipated expiration: 2023-06-05
Also published as: GB0312953D0; GB2404913B

Abstract

A liquid delivery system for use with a tanker comprising a pump a gas extractor 3 a liquid meter 4 a wet line delivery hose 5 and a dry line delivery hose 6 in which the gas extractor 3 is provided with a gas vent 7 and a gas diversion passage 8 extending to the dry line delivery hose 6 and provided with an expansion box 9 and closure means 10 and in which a first two-way valve 11 can direct gas from the gas extractor 3 to the gas vent 7 or the gas diversion passage 8 and a second two-way valve 12 can direct liquid to the wet line delivery hose 5 or the dry line delivery hose 6 and in which the first and second two-way valves 11,12 are synchronised so when the first two-way valve 11 directs gas to the gas diversion passage 8 the second two-way valve 12 directs fuel to the dry line hose 6 and when the first two-way valve 11 directs gas to the gas vent 7 the second two-way valve directs fuel to the wet line hose 5.

Description

Liquid Delivery System This invention relates to a liquid delivery system,

particularly, but not exclusively for use with a fuel tanker.

Fuel tankers which dispense a liquid fuel through a hose connected to a tank use either a wet or a dry line delivery system. With a dry line the hose is pumped clear after delivery, whereas with a wet line the hose remains filled with fuel.

A wet line system suffers from the disadvantage that the hose is permanently filled with fuel, which makes it awkward to manoeuvre. In addition, when a second type of fuel is to be dispensed after a first, the second type of fuel is pumped into the hose to purge the first type. This can lead to product contamination. Further, once the hose is primed with one type of fuel, no other types of fuel can be readily dispensed, which can lead to operational complications.

With both systems the quantity of fuel dispensed must be accurately measured. In a common arrangement a liquid meter is provided, which measures the fuel as it passes into the hose. To maintain an accurate measurement any air which enters the system is extracted by an air eliminator device upstream of the meter, so the meter only measures fuel.

However, this system is open to fraudulent abuse, because the air vent upstream of the meter can be blocked, so both air and fuel enter the meter and an inaccurate measurement is made.

This problem is addressed with a wet line system by having an approved and regularly checked vent which cannot be tampered with.

However, the same problem can be overcome with a dry line system without having to provide such a vent.

ln GB 2120208 in the name of the applicant, air extracted by an air eliminator box is captured in pipe work and an expansion box. The captured air is then re- introduced to the dry line hose after the fuel has been delivered and the hose is being pumped clear. This system can only be used with a dry line system, because the air cannot be reintroduced to a wet line hose.

Therefore, a dry line system has three main advantages over a wet line system. 1) The hose is lighter and more manoeuvrable, in particular when large bulk delivery hose is used; 2) multiple fuel types can be delivered from one tanker with a reduced risk of contamination; and, 3) the operational complications of line purging a wet hose system between fuel types are avoided.

However, the majority of today's delivery systems are wet line arrangements, because this was the most cost effective approach in the past when many of today's tanker delivery firms had to choose a system to adopt.

One advantage of a wet line system is that a delivery can be terminated simply by closing a second stop valve at the end of the wet line hose, which allows a customer's storage tank to be filled to the top. With a dry hose system the operator must allow sufficient ullage in the customer's tank at the end of the delivery to allow the content of the hose to be accommodated.

The present invention is intended to provide a novel approach.

Therefore, according the present invention a liquid delivery system for use with a tanker comprises a pump, a gas extractor, a liquid meter, a wet line delivery hose and a dry line delivery hose, in which the gas extractor is provided with a gas vent and a gas diversion passage extending to the dry line delivery hose, which is provided with an expansion box and closure means, and in which a first two-way valve can direct gas from the gas extractor to the gas vent or the gas diversion passage, and a second two-way valve can direct liquid to the wet line delivery hose or the dry line delivery hose, and in which the first and second two-way valves are synchronized so when the first two-way valve directs gas to the gas diversion passage the second two-way valve directs fuel to the dry line hose, and when the first two-way valve directs gas to the gas vent the second two-way valve directs fuel to the wet line hose.

In a preferred construction a first stop valve may be provided downstream of the meter, and a second stop valve may be provided at the outer end of the wet line hose.

The closure means may comprise a first spring loaded check valve, which is provided downstream of the expansion box, and which is biased against the flow of gas from the expansion box. Further, the first check valve prevents pressurised liquid passing into the gas diversion passage from its opposite side in use.

A second spring loaded check valve can be provided downstream of the first stop valve, and can be biased against the flow of liquid, or gas, arriving from the meter. A gas pressure passage can extend from the gas extractor to the opposite side of the second check valve, thereby to act against the opposite side of the second spring loaded check valve in use, to keep it firmly shut in the event that only gas is supplied to the meter, and an equal pressure of gas arrives at either side of the second spring loaded check valve.

Preferably the delivery system may have a wet line delivery mode and a dry line delivery mode which operate as follows.

In the wet line delivery mode the first two-way valve directs gas to the gas vent, and the second two-way valve directs liquid to the wet line delivery hose. The first stop valve is open, and the second stop valve is opened and closed to control the flow of liquid. Liquid is pumped by the pump to the gas extractor where any gas

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is extracted and diverted to the gas vent. The liquid continues over the meter and pushes the second check valve open, and proceeds down the wet line delivery hose.

The quantity of liquid passing over the meter is equal to the quantity of liquid exiting the wet line delivery hose, so an accurate measurement of the delivery can be taken.

In the dry line delivery mode the first two-way valve directs gas to the gas diversion passage, and the second two-way valve directs liquid to the dry line delivery hose. The first stop valve is opened and closed to control the flow of liquid. Liquid is pumped by the pump to the gas extractor where any gas is extracted and diverted to the gas diversion passage. The liquid continues over the meter and pushes the second check valve open, and proceeds down the dry line delivery hose.

The gas sent to the gas diversion passage may rejoin the fuel entering the dry line hose, when sufficient pressure has built up to open the first check valve.

The liquid passing over the meter is the liquid which is being delivered, so an accurate measurement of the delivery can be taken.

When the correct delivery has been made, the first stop valve can be closed to stop further liquid passing into the dry line hose. (Alternatively a stop valve on the tanker is closed to stop further liquid entering the system.) Gas is then introduced into the system either from an empty liquid compartment in the tanker, of from atmosphere. The first stop valve is reopened if it has been shut, and the pump is run. As a result gas is pumped through the system and the dry line delivery hose is purged of its remaining liquid.

If during the delivery of liquid the supply runs dry, gas must not pass over the meter and into a hose as this would lead to an inaccurate measurement being taken.

The gas pressure passage prevents this. If the liquid supply does run dry and gas passes to the meter, gas will also go down the gas pressure passage and act against the opposite side of the second check valve. Therefore, an equal amount of gas pressure will act on each side of the second check valve, and it will be closed by its spring, preventing any gas passing over the meter from going into a hose.

Preferably the dry line delivery hose may be adapted for bulk deliveries and have a diameter of greater than approximately 38mm, and the wet line delivery hose may be adapted for smaller deliveries and have a diameter of substantially 38mm.

In a preferred construction the tanker is a road tanker, and the liquid to be delivered is a liquid fuel, for example kerosene, diesel and so on. With such a construction the gas to be extracted will be any air which may enter the system.

Preferably the tanker comprises a number of fuel compartments, and is adapted to dispense a number of different types of fuel.

The pump, meter and valves can be any appropriate type adapted for use with such a fuel delivery system. The system can also be provided with appropriate liquid filters.

The invention also includes a liquid transportation vehicle provided with a liquid delivery system comprising a pump, a gas extractor, a liquid meter, a wet line delivery hose and a dry line delivery hose, in which the gas extractor is provided with a gas vent and a gas diversion passage extending to the dry line delivery hose and provided with an expansion box and closure means, and in which a first two-way valve can direct gas from the gas extractor to the gas vent or the gas diversion passage, and a second two-way valve can direct liquid to the wet line delivery hose or the dry line delivery hose, and in which the first and second two-way valves are synchronized so when the first two-way valve directs gas to the gas diversion passage the second two-way valve directs fuel to the dry line hose, and when the first two-way valve directs gas to the gas vent the second two-way valve directs fuel to the wet line hose.

The invention can be performed in various ways, but one embodiment will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic view of a liquid delivery system according to the present invention; Figure 2 is a diagrammatic view of the liquid delivery system as shown in Figure 1 in use in a first arrangement; Figure 3 is a diagrammatic view of the liquid delivery system as shown in Figure 1 in use in a second arrangement; Figure 4 is a diagrammatic view of the liquid delivery system as shown in Figure 1 in use in a third arrangement; Figure 5 is a diagrammatic view of the liquid delivery system as shown in Figure 1 in use in a fourth arrangement; and, Figure 6 is a diagrammatic view of the liquid delivery system as shown in Figure 1 in use in a fifth arrangement.

In Figure 1 a fuel delivery system 1 for use with a tanker comprises a pump 2, an air extractor 3, a fuel meter 4, a wet line delivery hose 5 and a dry line delivery hose 6.

The air extractor 3 is provided with an air vent 7 and an air diversion passage 8 extending to the dry line delivery hose 6 and which is provided with an expansion box 9 and first spring loaded check valve 10, provided with 1.5 psi of spring pressure.

First two-way valve 11 can direct air from the air extractor 3 to the air vent 7 or the air diversion passage 8, second two-way valve 12 can direct fuel to the wet line delivery hose 5 or the dry line delivery hose 6.

The first and second two-way valves 11 and 12 are synchronised so when the first two-way valve 11 directs air to the air diversion passage 8 the second two-way valve 12 directs fuel to the dry line hose 6, and visa versa.

First stop valve 13 is provided downstream of the meter 4, and second stop valve 14 is provided at the outer end of the wet line hose 5.

Further, second spring loaded check valve 15, which is provided with 10 psi of spring pressure, is provided downstream of the first stop valve 13.

Air pressure passage 16 extends from adjacent the air extractor 3 to the opposite side of the second check valve 15.

The delivery system 1 further comprises a fuel tank 17, comprising a number of separate fuel compartments 18, each of which is provided with a stop valve 19. In addition a first filter 20, a second filter 21 and air vent moisture gathering box 22 are provided.

The wet line delivery hose 9 is provided on a drum 23, and further comprises a delivery spout 24 adjacent the second stop valve 14.

The dry line delivery hose 6 has a diameter of 75mm, and the wet line delivery hose 5 has a diameter of 38mm.

The delivery system 1 can be used in a wet line delivery mode and a dry line delivery mode, as shown in Figures 2, 3, and 4.

ln Figure 2 the delivery system 1 is in wet line delivery mode and a delivery is in progress. (Cross-hatched arrows indicate the passage of fuel, and plane arrows indicate the passage of air.) Fuel is pumped by the pump 2 from one of the compartments 18 of the tank 17 to the air extractor 3. Any air removed proceeds to the first two-way valve 11, where it is directed to the air vent 7, and vented to atmosphere. Air- less fuel continues over the meter 4, through the open stop valve 13 and the second check valve 15 to the second two-way valve 12. From there the fuel is directed to the wet line hose 5.

The delivery is controlled by the opening and closing of the second stop valve 14. The quantity of fuel passing over the meter 4 is equal to the quantity of fuel which exits the spout 24, and therefore an accurate delivery measurement is taken.

At the end of the delivery the second stop valve 14 is closed and the pump 2 is stopped. The wet line delivery hose 5 is then re-wound onto the drum while still full of fuel. When the next delivery begins the stop valve 14 is opened and the fuel in the hose 5 forms the first part of the next delivery.

In the event that a wet line delivery of a second fuel from a different compartment 18 is to be made next, the stop valve 14 is closed when the delivery is complete bar a quantity equal to that in the wet line hose. The user then operates the appropriate valves 19 so the second fuel type can flow into the system. The stop valve 14 is then opened and the pump 2 operated for the brief period it takes to empty the wet line hose of the first fuel type. The wet line hose is then ready for immediate delivery of the second type of fuel at the next delivery.

In Figure 3 the delivery system 1 is in dry line delivery mode and a delivery is in progress. Fuel is pumped by the pump 2 from the tank 17 to the air extractor 3.

Any air removed proceeds to the first two-way valve 11, where it is directed to the air diversion passage 8, where it can be contained in the expansion box 9 by the first check valve 10. Air-less fuel continues over the meter 4, through the open stop valve 13 and the second check valve 15 to the second two-way valve 12. From there the fuel is directed to the dry line hose 6. If the air pressure in the air diversion passage 8 and the expansion box 9 increases to above 1.5psi, the first check valve 10 will open, and the air can pass into the dry line hose. This is not a problem since the air has not passed over the meter, so an inaccurate measurement will not be taken.

The delivery can be controlled by the opening and closing of the first stop valve 13, or by the opening and closing of the appropriate valve 19. The primary purpose of the first stop valve 13 is to close automatically once a predetermined quantity of fuel has passed the meter 4. In a known arrangement the meter 4 and the stop valve 13 are provided with a counter which facilitates the closure of the stop valve 13 when the predetermined quantity of fuel has passed over the meter 4.

Which ever valve 19 or 13 is used to stop the delivery, it must be shut when the meter reading is short of the desired delivery quantity by an amount equal to the capacity of the system between the tank 17 and the meter 4. This is because the fuel present in that portion of the system will be pumped through the system when air is introduced as described below.

As shown in Figure 4 air is then introduced into the system 1 either from an empty compartment 18 or by disconnecting the supply hose from the tank 17 and drawing in air from atmosphere. The first stop valve 13 is reopened if it has been shut, and the pump 2 is run. As a result the fuel present between the tank 17 and the meter 4 is pumped through the air extractor 3, over the meter 4 and into the dry line hose 6. When that fuel has passed through the air extractor 3, the pressurised air following it is sent to the air diversion passage 8, through the first check valve 10 and into the dry line hose 6. The pressurised air ensures that the hose 6 is purged of its remaining fuel, which ensures that the full quantity of fuel measured by the meter 4 is transferred to the customer's tank.

Figures 5 and 6 show what can happen in the event of an air pressure build up in the system 1. This can happen if the tank 17 runs dry unexpectedly, or if there is a blockage somewhere in the system 1. If such a thing happens, it is important to prevent air passing over the meter 4 and into one of the hoses, 5, 6, as this could lead to an inaccurate measurement being taken. The air pressure passage 16 prevents this.

If any air passes through the air extractor box 3 and passes over the meter 4, it flows to the second check valve 15. However, air will also pass down the air pressure passage 16, and creates an equal air pressure on the opposite side of the second check valve 15. As the second check valve 15 is spring loaded against the flow from the meter 4 with 10 psi of pressure, the valve 15 stays shut.

Thus a fuel delivery system is provided which can make bulk deliveries of multiple fuel types using a light and manoeuvrable wide diameter hose, while also being able to make smaller deliveries using the popular and quicker wet line arrangement.

It will also be appreciated that the delivery system uses novel arrangement to utilise a single pump, air extractor, meter and air pressure activated check valve mechanism for both delivery modes.

Claims

Claims 1. A liquid delivery system for use with a tanker comprising a

pump, a gas extractor, a liquid meter, a wet line delivery hose and a dry line delivery hose, in which the gas extractor is provided with a gas vent and a gas diversion passage extending to the dry line delivery hose and provided with an expansion box and closure means, and in which a first two-way valve can direct gas from the gas extractor to the gas vent or the gas diversion passage, and a second two-way valve can direct liquid to the wet line delivery hose or the dry line delivery hose, and in which the first and second two-way valves are synchronized so when the first two-way valve directs gas to the gas diversion passage the second two-way valve directs fuel to the dry line hose, and when the first two-way valve directs gas to the gas vent the second two-way valve directs fuel to the wet line hose.
2. A liquid delivery system as claimed in Claim 1 in which the closure means comprise a first spring loaded check valve, which is provided downstream of, and i adjacent the expansion box, in which the first spring loaded check valve is biased against the flow of gas.
3. A liquid delivery system as claimed in Claim 2 in which a second spring loaded check valve is provided downstream of, and adjacent the first stop valve, and is biased against the flow of liquid, or gas, arriving from the first stop valve.
4. A liquid delivery system as claimed in Claim 3 in which a gas pressure passage extends from the gas extractor to the opposite side of the second spring loaded check valve, in which pressurised gas passing to the gas pressure passage can act against the opposite side of the second spring loaded check valve in use.
5. A liquid delivery system as claimed in Claim 4 in which the first spring loaded check valve is loaded with approximately 1.5 psi of pressure and the second spring loaded check valve is loaded with approximately 10 psi of pressure
6. A liquid delivery system as claimed in any of the preceding Claims in which a first stop valve is provided downstream of, and adjacent the meter, in which the first stop valve can be opened and closed to control the supply of liquid to the dry line delivery hose.
7. A liquid delivery system as claimed in Claim 2 in which a second stop valve is provided at the outer end of the wet line hose, in which the second stop valve is opened and closed to control the supply of liquid exiting the wet line delivery hose.
8. A liquid delivery system as claimed in any of the preceding Claims in which the dry line delivery hose has a diameter of greater than substantially 38mm, and the wet line delivery hose has a diameter of substantially 38mm.
9. A liquid delivery system as claimed in any of the preceding Claims in which filter means are provided upstream of the pump and upstream of the gas extractor.
10. A liquid delivery system as claimed in any of the preceding Claims in which the liquid is a liquid fuel and the gas to be extracted is air.
11. A liquid delivery system as claimed in any of the preceding Claims in which the wet line delivery hose is provided on a drum.
12. A liquid delivery system as claimed in any of the preceding Claims in which the air vent is provided with a moisture gathering box.
13. A liquid delivery system substantially as described herein and as shown in the accompanying drawings.
14. A liquid transportation vehicle provided with a liquid delivery system as claimed in any of the preceding Claims.