IES970901A2 - Method and apparatus for on board adding of an additive to a fluid carried on a tanker truck - Google Patents

Abstract

The apparatus is a dosing apparatus which is suitable for adding petrol performance additive to petrol and diesel oil performance additive to diesel oil on tanker trucks carrying these oils. The apparatus includes an additive tank (3, 4), a pump (5) and a distribution line (6, 7). Dosing is carried out through the top region of the tank compartments (2). The apparatus is operable when the truck is in transit. Output from the pump (5) is routed through branch lines (8, 9) taken from the main distribution line (6, 7), each corresponding to one of the tank compartments (2) and each branch line (8, 9) being provided with an isolating valve (11).

Description

BOARD ADDING OF AN ADDITIVE TO A FLUID CARRIED ON A TANKER TRUCK The present invention relates to a method and apparatus for on board adding of an additive to a fluid carried on a tanker truck. The invention relates particularly, although not exclusively, to on board adding of performance additives to oils, such as petrol or diesel oil, on tanker trucks with separate tank compartments. Adding of an additive is also referred to as dosing.

Performance additives are most commonly added to oils such as petrol or diesel oil, hereafter collectively referred to as oil, before the oil is loaded onto the tanker truck, However, an oil distributor may sometimes prefer to add such additives on board the tanker truck. This may arise where the distributor wishes to have direct control over the quality of the dosing process or where the distributor wishes to reduce his dependence on the primary supplier of the base oil product.

Typically, oil tanker trucks have about six or seven separate compartments. When they discharge oil into the storage tanks at the delivery site, usually about three compartments on the truck are discharged simultaneously in order to' shorten the time taken for delivery.

Frequently, all of the compartments will not be fully loaded. There are several reasons for this. One reason is that petrol and diesel oil have different densities and the volume capacity of the truck will be determined by the least dense oil. Another reason is that tanker trucks are frequently provided with tank volume capacities which anticipate future increases in legally permissible maximum payloads or overall vehicle weights.

On board addition of performance additives on tanker trucks, carrying both petrol and diesel oil, is known in the prior art. The truck is typically provided with two additive storage tanks, one for petrol additive and one for diesel additive. Each tank is connected to each of the compartments of the tanker truck by manifolded branch lines or pipes which enter the discharge pipe of each compartment. Each of the branch lines entering the _ int ci g /Self AL Ac/ ______ IE 970901 discharge pipes is provided with its own largely independent pneumatic injection pump and pneumatic control system. The control system comprises pneumatic counters which, when initiated, provide a fixed number of strokes of the pump which accordingly pumps a fixed quantity of additive. This fixed quantity typically corresponds to the quantity required for a full compartment of oil. The dosing system is automatically operated and doses the fixed quantity into the oil when the oil in the compartment is being discharged into the storage tank at the delivery site. The system is duplicated on the truck for each of the additives to avoid cross contamination in the pumps and lines. Pneumatic equipment is used for the control system because safety regulations do not usually permit the use of electrical equipment when discharging petrol.

This ty pe of system has several disadvantages. Firstly, it requires two pumps and two control systems for each of the tank compartments. This is costly and complicated. Secondly, pneumatic control equipment can be unreliable when used with a truck compressed air system where it is difficult to maintain consistent air quality. Thirdly, pneumatic components are limited in their ability to control and record information. Fourthly, the addition of the additive through entries made into the discharge pipes presents a potential hazard because the entire compartment contents could be discharged onto the roadway if the entries or lines ruptured or leaked. Fifthly, the addition of a fixed amount of additive when discharging oil from a compartment causes the oil to be over dosed when the compartment is not full. This in turn gives rise to several problems. It is wasteful of additive, which is relatively expensive. It prevents proper quality control and customer assurance of additive proportions in the oil. It prevents accurate monitoring of additive proportions in the oil over a period of time and may accordingly allow circumstances to go undetected where no additive at all has been added.

It is an object of the present invention to overcome some or all of the disadvantages of the prior art method as set out above.

IE 970901 The present invention provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including an additive tank, a pump and a distribution line, characterised in that dosing is carried out through the top region of the tank compartments.

The present invention also provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including an additive tank, a pump and a distribution line, characterised in that the output from the pump is routed through branch lines taken from the main distribution line, each corresponding to one of the tank compartments and each branch line is provided with an isolating valve.

The present invention further provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including two additive tanks, two pumps and two distribution lines, characterised in that the output from the pump is routed through branch lines taken from the main distribution line, each corresponding to one of the tank compartments and an isolating valve and common entry is shared between a pair of branch lines entering a compartment. Advantageously, each branch line is provided with a nonreturn valve to prevent cross flow between the two distribution lines.

The present invention further provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including a dosing sub-system comprising an additive tank, two pumps and two distribution lines, characterised in that the distribution lines from each of the two pumps are branched to a different set of compartments, whereby both pumps may be run simultaneously.

The present invention also provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including an additive tank, a pump and a distribution line, characterised in that the apparatus is operated when the truck is in transit, The present invention additionally provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including an additive tank, a pump, a distribution line and a computer, characterised in that the apparatus includes a monitoring element IE 970901 which comprises a flow sehsor on the distribution line which detects if flow is occurring in the line. The flow sensor comprises an element which is partially free to move in a substantially vertical section of the distribution line. Flow in the distribution line must pass the element. The position of the element is detected by an electrical sensor which signals the computer. Each flow pulse from the pump lifts the element and operates the electrical sensor. The element subsequently returns to its rest position by the force of gravity. i The present invention further provides an apparatus for dosing fluids on board a truck with IO tank compartments, the apparatus including an additive tank, a pump, a distribution line and a computer, characterised in that the apparatus includes a monitoring element which comprises a magnetic element on the pump piston and external electrical sensors which can detect the proximity of the magnetic element, located adjacent the fully forward or fully returned positions of the piston where the switches signal the piston position to the computer, whereby a check is made that the injection pump piston achieves its full forward or return stroke The present invention additionally provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including an additive tank, a pump, a distribution line, an isolation valve and a computer, characterised in that the apparatus includes a monitoring means which momentarily attempts to operate the pump before the isolation valve is opened, whereby a cheek is made that the system remains pressure tight or all isolation valves on the distribution line and its branch lines are closed.

The present invention also provides an apparatus for dosing fluids on board a truck with tank compartments, the apparatus including an additive tank, a pump, a distribution line and a computer, characterised in that the apparatus includes a computer programme which assists in determining the correct compartment load arrangement and which additionally sets the correct dosing programme for the compartments.

IE 970901 The invention will now be described more particularly with reference to dosing apparatus which is suitable for adding petrol performance additive to petrol and diesel oil performance additive to diesel oil on tanker trucks carrying these oils. The apparatus comprises two dosing sub-systems with some common parts.

Each dosing sub-system comprises an additive storage tank, an injection pump and a set of distribution lines and valves. The two dosing sub-systems have a common control system.

Each additive storage tank is connected to a pump and both the additive storage tank and IO the pump are located on the truck below the level of the tank compartments. The pump comprises a pneumatic reciprocating injection pump which is operated by air pulses from an electrical solenoid valve using compressed air from the truck system.

The output from each pump is routed through a main distribution line which is routed up to and along the top of the tank compartments. The output is then routed through a series of branch lines taken from the main distribution line, each corresponding to one of the tank compartments. Each branch line is fitted with an isolating valve. Each branch line enters one of the compartments through its upper surface to permit discharge of additive into the compartment. The branch line terminates in a spring loaded non-retum valve positioned just within the compartment. One purpose of the non-retum valve is to prevent oil spilling from the compartment in the accidental event of the truck turning over. A second purpose is to retain additive within the line when the system is not in operation.

If the pumps are not run simultaneously, then a single isolating valve and non-retum valve may be shared between each pair of branch lines entering a compartment. This is achieved by fitting each branch line with an additional non-retum valve, to prevent cross flow between the two main distribution lines, and then connected the two branch lines destined for each compartment into a single branch line fitted with the isolating valve and the nonreturn-valve within the compartment. In this arrangement, when the system is operated, the compartments are dosed one at a time IE 970901 Each isolating valve may comprise a conventional air pilot operated valve controlled by a remote electrical solenoid operated valve taking air from the truck system All of the electrical solenoid operated valves may then be mounted in a protective enclosure located in a convenient position on the truck.

The control system comprises an electronic control device, such as a computer or microprocessor, henceforth referred to as the computer, which is located within the cab of the truck. The computer is connected to the solenoid valves controlling the injector pump and to the solenoid valves controlling the isolation valves. The computer controls the output from each pump by directly pulsing the relevant pump solenoid valve and controls the compartment to be dosed by operating the relevant isolation solenoid valve.

As mentioned above, where a single isolating valve is shared between a pair of branch lines routed to a compartment, the compartments are dosed one at a time If the overall dosing time of all of the compartments is found to be too long and if it is not feasible to increase the pumping rate of the injector pump, then the dosing time may be reduced by various methods including the following. The number of injector pumps in one of the dosing subsystems is increased to two and the distribution lines from each of the two pumps are branched to a different set of compartments. This allows both pumps to be run simultaneously and thereby reduces the dosing time. This is particularly useful where the average quantity of one oil type predominates over the other, the two pumps being used with the dosing sub-system for the predominant oil type.

Usually it is not permitted to operate any electrical device from the truck electrical system when the truck is loading or discharging petrol. The additive systems are therefore usually operated while the truck is in transit between the loading terminal and the delivery site.

The operation of the dosing apparatus is not directly attended by the driver when dosing takes place when the truck is in transit. It is therefore important that the equipment works reliably and that its operation is checked by an automatic monitoring system. If the IE 970901 monitoring system detects a fault, then dosing is automatically stopped or an acceptable default action is taken. The monitoring system includes several elements.

One element of the monitoring system includes a flow switch on each main distribution line which detects if flow is occurring in the line. The flow switch comprises a magnetic weight which is partially free to move in a vertical tube which is arranged to form part of the distribution line. Flovy in the distribution line must pass around the magnetic weight. The position of the magnetic weight is detected by an electrical reed switch sensor which signals the computer. Each flow pulse from the injection pump lifts the magnetic weight and switches the reed switch The magnetic weight subsequently returns to its rest position by the force of gravity.

A second element of the monitoring system includes a check that the injection pump piston achieves its full forward and return stroke. This is achieved by providing the injection pump with a magnetic piston and external electrical reed switches, located adjacent the fully forward and fully returned positions of the piston, which signal the piston position to the computer.

A further element of the monitoring system includes a check that the system remains pressure tight and all isolation valves on the distribution line and its branch lines are closed unless otherwise signalled by the computer. This is achieved by momentarily attempting to operate the pump before the relevant isolation valve is opened. The pump should stall and the flow switch should indicate no flow.

As mentioned earlier, the various compartments of a tanker truck will frequently not be fully loaded. Where this is the case, it is necessary for the driver to balance the loads in the various compartments for reasons of road safety. If the truck is to carry its maximum permitted payload, then the only variable between different load arrangements will be the relative proportions of the different types of oil. The computer can be programmed to assist the driver in determining the conect compartment load arrangement. Where the driver uses the arrangement proposed by the computer, this information can be very IE 970901 conveniently used to additionally set the correct dosing programme for each of the compartments on the computer without further effort by the driver. This also has the advantage that there is less chance of errors being made in setting the dosing programme.

The computer has a memory capability which records the time, date and compartment loading details of each delivery The computer also maintains a record of the cumulative usage of each oil type and each additive type This information allows a distributor to audit the usage of additives and to provide an historic record against which any discovered discrepancies can be checked.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined in the specification.

MACLACHLAN & DONALDSON Applicants’ Agents 47 Merrion Square Dublin 2 IE 970901

Claims (6)

CLAIMS:

1. Apparatus for dosing fluids on board a truck with tank compartments, the apparatus including an additive tank, a pump and a distribution line, characterised in that dosing is carried out through the top region of the tank compartments.

2. Apparatus for dosing fluids on board a truck with tank compartments, according to Claim 1 in which the apparatus is operable when the truck is in transit.

3. Apparatus according to Claim 1 or Claim 2, in which the output from the pump is routed through branch lines taken from the main distribution line, each corresponding to one of the tank compartments and each branch line is provided with an isolating valve, optionally in which the output from the pump is routed through branch lines taken from the main distribution line, each corresponding to one of the tank compartments and an isolating valve and common entry is shared between a pair of branch lines entering a compartment; optionally in which each branch line is provided with a non-return valve to prevent cross flow between the two distribution lines; optionally in which the distribution lines from each of the two pumps are branched to a different set of compartments, whereby both pumps may be run simultaneously; optionally in which the apparatus includes a monitoring element which comprises a flow sensor on the distribution line which detects if flow is occurring in the line, the flow sensor comprising an element which is partially free to move in a substantially vertical section of the distribution line; optionally in which flow in the distribution line is directed to pass the monitoring element, the position of the monitoring element being detected by an electrical sensor which signals a control computer, each flow pulse from the pump lifting the monitoring element and operating the electrical sensor, and with the element subsequently returning to its rest position by the force of gravity.

4. Apparatus according to Claim 1 or Claim 2, in which the apparatus includes a monitoring element which comprises a magnetic element on the pump piston and external electrical sensors which can detect the proximity of the magnetic element, located adjacent the fully forward or fully returned positions of the piston where the switches signal the IE 970901 ΙΟ piston position to the computer, whereby a check is made that the injection pump piston achieves its full forward or return stroke.

5. Apparatus according to Claim 1 or Claim 2, in which the apparatus includes a 5 monitoring means which momentarily attempts to operate the pump before the isolation valve is opened, whereby a check is made that the system remains pressure tight or all isolation valves on the distribution line and its branch lines are closed and optionally in which the apparatus includes a computer programme which assists in determining the corect compartment load arrangement and which additionally sets the correct dosing

6. 10 programme for the compartments.