GB2066769A - Tanker filling apparatus - Google Patents

Abstract

In a tanker filling installation having a retractable filling pipe (12) which can be lowered into a tank (71) of a tank car, the filling pipe (12) carries a liquid level detector (70) adjacent its lower end. When the detector (70) becomes immersed in the liquid injected into the tank (71), a signal is given to increase the filling rate or alternatively to stop delivery. The detector (70) is preferably a thermistor. <IMAGE>

Description

SPECIFICATION Tanker filling apparatus This invention relates to tanker filling apparatus which may be of the type described in British patent specification No. 11 76992, including at least two filling pipes provided for filling road or rail tankers with different products, of, e.g. a refinery or oil products storage station.

In specification No. 11 76992, a guide device was described to guide any selected one of a number of horizontally spaced filling pipes to a common filling station, as the selected pipe is lowered from a retracted position. It is then only necessary to bring the tanker manhole to that station, which is the same regardless of the supply pipe to be utilised. The possibility of the tanker being brought to a position in which the manhole is aligned with a pipe other than that to be used is thus eliminated.

When filling a tanker, it is not always easy to ascertain the level of the liquid in the tank; for example the tank may contain residual liquid when it arrives at the filling station. The danger of overfilling and spillage is therefore present.

Also, when filling a tanker with a highly inflammable (high vapour pressure) light fuel, it is necessary to restrict the flow rate of the discharge from the filling pipe until the tip of the pipe is in contact with the fuel within the tanker; if a high rate is adopted from the start, the electrostatic charge built up on the surface of the liquid, resulting from the high turbulent flow through the filling pipe, may cause spark discharge from the liquid surface to the earthed pipe tip when spaced from that surface, with the attendant risk of explosion. Once the tip is in contact with the liquid, the danger of a spark discharge is eliminated and the flow rate can be increased.

It has therefore been the practice to lower the tip as far as possible into the tank of the tank car and to deliver the fuel as the low flow rate, until it is estimated by use of flow meters or by observation of the change of detected weight of the tank car that the tank has been sufficiently filled to cover the end of the tip.

However, the level of liquid in the tank during ,filling cannot be accurately determined by those methods. The tank dimensions vary from tanker to tanker; if the tanker contains liquid on arrival, the ,tip of the filling pipe and the liquid may be immediately in contact and initial filling at low rate is unnecessary; if the tip is obstructed, for example by heating pipes within the tanker, and cannot reach the bottom of the tank, filling should be continued for a longer period.

In accordance with the present invention, tanker filling apparatus comprises a filling pipe, means for lowering and retracting the pipe to introduce and withdraw the lower end of the pipe into or from a tank, and a liquid level detector.

Preferably the liquid level detector is so positioned that, when the pipe is inserted in a tank, the detector is located at the maximum level to which the tank is to be filled. The detector may then be arranged to stop further filling when it becomes immersed in the liquid.

Alternatively, the liquid level detector may be carried by the filling pipe adjacent its lower end to indicate remotely when that lower end is immersed in liquid discharged from the pipe into the tank. Then, filling can be accomplished at a low safe rate until the detector has indicated that the lower end of the filling pipe has been covered by the liquid, when the rate is increased.

Preferably, change-over from slow filling to fast filling is effected automatically under control of the detector.

By the use of the detector, the time occupied by slow filling is kept to a minimum while safety is maintained.

Where the tanker filling apparatus comprises a guide device which at its upper end is dimensioned to receive any selected one of a number of horizontally spaced and lowerable flexible filling pipes and is shaped to guide any such pipe that is lowered to a common supply position, the liquid level detector may be provided on at least those pipes intended to supply light fuels.

A filling pipe preferably carries two liquid level detectors, one positioned at the tip and the other at the maximum filling level.

A problem arises where the filling apparatus is to deliver heavy fuels ("black oils") and light fuels ("white oils"). It is thought by some operators that the pipes delivering the black oils can cause contamination of the guide device which in turn contaminates the exteriors of the filling pipes for the white oils. To avoid all possibility of contamination of the white oils pipes from the black oils pipes, it may be advantageous to segregate the two sets of pipes. To that end, the guide device may comprise a pair of funnels arranged side by side, for receiving and guiding the filling pipes of different sets of such pipes.

The invention will be more readily understood by the following description of tanker filling apparatus in accordance therewith, reference being made to the accompanying drawings, in which: Figure 1 is a partly cut-away side view of the apparatus; Figures 2 and 3 are sections on the lines 11-Il and Ill-Il I of Figure 1, respectively; Figure 4 shows the end of a filling pipe inserted in a tank to be filled, and illustrates the use of level detectors; and Figures 5 to 7 illustrate the use of a twinfunnel, and are respectively a side view, an end view and a plan view of the filling equipment shown in conjunction with a tank car.

The installation shown in the drawings has four stiffly flexible filling pipes, the positions of which when in their retracted positions are indicated diagrammatically at 12 in Figure 3; in Figures 1 and 2, one 1 2A of the pipes is shown in its filling position, while others, 1 2B and 1 2C, are shown in retracted position in Figures 1 and 2 respectively.

A guide device in the form of a funnel 13 is mounted below the filling pipes when the latter are in their retracted positions. The funnel 13 at its uppermost part is sufficiently wide to receive any selected one of the four pipes when lowered vertically from the retracted position, and converges to a circular-section tube 1 3A having a diameter somewhat larger than that of the pipes.

For each of the four pipes 12 there is a reel, on which the pipe is wound when retracted. The reels are similar to one another and each can rotate about a horizontal axis, two of the reels being coaxial and located on one side of the vertical plane through the funnel 13, and the other two reels being coaxial on the other side of that plane.

The four reels are carried in a lattice framework 15, from which the funnel 1 3 is centrally suspended; the framework has two parallel and vertical sides 16, between which the reels are located, as shown in Figure 2.

The reel shown in detail in Figures 1 and 2 will now be described, it being understood that the other reels are similarly constructed. The reel consists of an annular plate 1 7 to which is secured a number of radial spokes 18, carrying outwardly opening saddles 20, each of which can receive the associated filling pipe 12. The reel is mounted for rotation about its central horizontal axis relative to the frame 1 5. For that purpose, a plate 21 (Figure 1) is attached to the framework in the area of the reel axis and has attached to it the inner race of a slewing ring 22, the outer race of which is bolted to the annular plate 17. The outer race of slewing ring 22 has gear teeth 23, with which a pinion 24 of a driving motor 25 mesh, the shaft of motor 25 passing through a suitable opening in the plate 21.The associated filling pipe 12 is attached by a hose clamp 26 to a rigid pipe 27, incorporating two elbow joints 28 and 30. The elbow joint 30 brings the pipe 27 to the axis of the reel, the pipe 27 then extending through the central openings of the annular plate 17 and the slewing ring 22. The pipe 27 is connected through a rotary joint 31 to a flanged stub pipe,32 which is permanently connected to an oil supply.

The rigid pipe 27 is caused to move with the reel by being coupled to the reel through a resilient connection. Thus, as shown in Figure 1, a cross member 33 is carried by three of the spokes 18 and supports a plate 34 spaced from the pipe 27. A spring 35 is interposed between the plate 34 and the pipe 27 and a rod 36 is attached to the pipe 27, passes through the spring 35 and the plate 34, and carries a stop 37, which is normally held against the upper side of plate 34 by the action of spring 35; stop 37 thus determines the maximum separation of the pipe 27 from the member 33.

The right hand half of Figure 1 shows the filling pipe 13 in both the fully down position (full line) and in the fully retracted position (chain line). As the reel is rotated clockwise by the motor 25, the flexible pipe 1 3 is successively received by the saddles 20 and is thus wound on the reel with the pipe 27 turning with the reel. The stopping position of the reel in the retracted disposition of the filling pipe 13 depends on the length of the filling pipe; the position of the rigid pipe 27 is shown at 27A and 27B for two such lengths.The motor 25 is cut out at the required stopping position of the reel by means of a known limit switch mechanism, consisting of a ferrous flag 38 carried by a selected spoke 18 or on a part annular tie 40, and received at the requisite angular position of the reel within a slotted reed switch 41 carried by the frame 1 5. The arrangement is such that, when the flag 38 is received in the reed switch 41, the switch is operated electromagnetically to de-energise the motor 25 and apply an associated brake. A similar stop mechanism is provided to de-energize the motor 25, when the reel reaches the fully down position, that mechanism comprising a flag 42 carried by a selected spoke 18 and a reed switch 43 carried by the frame 15.

In order to ensure that the filling pipe 12 is properly retained within the saddles 20, a series of guide rollers 44 are carried by the frame 1 5 at intervals around the reel, being slightly displaced from the filling pipe when the latter is properly seated in the saddles 20. Further, in order to guide the pipe into the saddles during raising of the pipe, a deflection roller 45 is positioned above the funnel 13.

Provision is made to stop the reel during the paying out of the filling pipe 12, should that pipe engage an obstruction before it reaches the fully down position determined by the switch mechanism 42, 43. When, during the descent of the filling pipe 12, the tip of that pipe meets an obstruction, there is a tendency for the pipe to be urged out of the saddles 20 above the funnel 13; elsewhere around the periphery of the reel, the pipe 12 is retained by the rollers 44. Displacement of the filling pipe away from the reel is sensed by a feeler 46 carried by a pivoted arm 47 which is biased downwardly by gravity. The position of the feeler 46 relative to the framework 1 5 is in turn sensed by a limit switch assembly 48 operating in a manner similar to that of the limit switch 38, 41.

Thus, the obstruction of the pipe 1 3 is detected by movement of the lever 47 and the consequential operation of the limit switch mechanism results in stopping of the motor 25.

If the obstruction is encountered when the filling pipe 12 is close to its fully down position, the rigid pipe 27 is held against further movement, while the reel, and in particular the cross member 33 continues to rotate. In those circumstances, the separation of the plate 34 from the pipe 27 is reduced, a flag 50 carried by the rod 36 rises relative to its reed switch 51 and, again, the motor 25 is stopped.

When one of the filling pipes 12 has been used for the discharge of fuel, and is raised to the retracted position, fuel will continue to drip from the pipe into the funnel 13. To prevent the liquid from contaminating the surroundings, a drip tray 52 is rotatably carried by a shaft 53, which passes through a vertical sleeve 54. The drip tray 52 which is connected by a pipe 55 to a slops tank (not shown) has a central operative position, in which it is disposed immediately beneath the lower end of the funnel 13. From that operative position, the tray 52 can be turned to either of two inoperative positions indicated at 52A and 52B in Figure 3; in either of those inoperative positions, the tray 52 is displaced from the funnel 13.

The drip tray 52 is driven automatically between its operative position and one or other of the inoperative positions by the movement of the reels. Thus, as shown particularly in Figure 3, the shaft 53 is disposed between the two reels on the right hand side of Figure 1, and has attached to it a bracket 56 carrying two pairs of arms 57 and 58. One spoke 18 of each of the reels on the right hand side carries an outwardly directed striker 60, which during rotation of the reel follows a path intersecting the arms. As the right hand reel shown in Figure 1 is turned to lower its pipe, the striker 60 engages one of the arms 58 when the tip of the pipe is just above the drip tray and causes the shaft 53 to turn and, thus, to rotate the drip tray to one of the inoperative positions.A similar movement of the other reel causes its striker to strike one of the arms 57 and to move the drip tray 52 to the other inoperative position.

When one of the reels is turned to retract a pipe 12, and the tip of that pipe has cleared the lower extremity of the funnel 13, the striker engages the other arm 57 or 58 and drive the shaft in the opposite direction to bring the drip-tray back into the operative position beneath the funnel 13. The shaft has an indexing mechanism 61 ensuring that the drip tray 52 adopts only its three possible positions and is not located between the operative position and either of its inoperative positions.

For the left-hand reels, an auxiliary shaft 62 carries two pairs of arms 63 (Figure 1) similar to the arms 57 and 58; arms 63 have been omitted from Figure 3 for the sake of clarity. Shaft 62 is coupled to shaft 53 through a pair of links 64 connected between cross arms 65 and 66 keyed to the shaft 53 and 62 respectively. Drip tray 52 is thus operated between its operative and inoperative positions by the action of the striker of each reel on the left-hand side of Figure 1, and through the linkage 64-66.

When filling a tanker with a highly inflammable (high vapour pressure) light fuel, it is necessary to restrict the flow rate of the discharge from the filling pipe until the tip 67 of the pipe 12 is in contact with the fuel within the tanker; if a high rate is adopted from the start, the electrostatic charge built up on the surface of the liquid and resulting from the high turbulent flow through the filling pipe may cause spark discharge from the liquid surface to the earthed pipe tip when spaced from that surface with the attendant danger of an explosion. Once the tip is in contact with the liquid, the danger of a spark discharge is eliminated and the flow rate can be increased.

It has therefore been the practice to lower the tip as far as possible into the tank of the tank car and to deliver the fuel at the low flow rate until it is estimated by use of flow meters or observation of the change of detected weight of the tank car that the tank has been sufficiently filled to cover the end of the tip. However, the level of liquid in the tanker during filling cannot be accurately determined by those methods. The tank dimensions vary from tanker to tanker; if the tanker contains liquid on arrival, the tip 67 and the liquid may be immediately in contact and initial filling at low rate is unnecessary; if the tip is obstructed, for example by heating pipes within the tanker, and cannot reach the bottom of the tank, filling at the lower rate should be continued for a longer period.

In order to minimise the duration of slow filling, without increasing the danger of spark discharge, the tip 67 of any pipe 12 required to discharge light fuels carries a level detector 70 as shown in Figure 4, which illustrates the lower part of the filling pipe 12 inserted within the tank 71 of a tank car. The detector 70 is placed as far down the tip 67 as convenientiy possible and is preferably a thermistor as sold under the name LEVTEC by Standard Telephone and Cables Ltd. The metai tip 67 is earthed through conducting reinforcement in the pipe which itself is made of antistatic hose.

The leads for the thermistor 70, as represented diagrammatically at 72 in Figure 4, are embedded in the tip 67 and in the wall of the pipe 12 and terminate in a control box 73, in which change of thermistor current resulting from contact of the thermistor with the fuel within the tank 71 is detected and used to control the valves controlling the flow rate of fuel through the pipe 12. While the detector 70 is above the surface level of the fuel 74 in the tank, the low flow rate is automatically maintained, but, when the surface reaches the detector, the resulting change in thermistor current initiates the high level of flow.

A second level detector 76, which is preferably similar to detector 70, is embedded in the wall of pipe 12 at a position such that, when the pipe is properly located in the tank 71 as shown, detector 76 is at the maximum level to which the tank is to be filled. Detector 76 is connected by leads 77 to the control box 73 and acts to prevent overfilling of tank 71. When detector 76 becomes immersed in the fuel, the resulting change in thermistor current causes the control box 73 to operate the supply valve to stop further filling of the tank.

When a filling pipe 12 is to be used to discharge light, inflammable, fuels and therefore submerged filling is desirable as explained above, the end of the filling pipe may be telescopic, as by having a separate termination length slidable in a sleeve encompassing and extending from the remaining pipe. Such a telescopic arrangement enables the pipe to be fully lowered, regardless of the presence in the tank of obstructing elements such as heater pipes or of differences in the level of the bottom of the tank. However, neither the level detector nor a telescopic arrangement is required for a filling pipe to be used for discharging heavy, low vapour pressure, fuels, which are less inflammable and which are normally splash loaded.

Where, for example, two of the filling pipes 12 are used for discharging heavy fuels ("black oils") and the other two are for the discharge of light fuels ("white oiis"), the use of a single funnel 13 as illustrated has the one minor disadvantage that drips from the black oils pipes could possibly contaminate the funnel 13, and hence the white oils pipes when subsequently used. To avoid all possibility of contamination, the modification shown in Figures 5 to 7 may be employed. In that modification the funnel 13 is replaced by a twin funnel 80 having two separate funnels 81 and 82, respectively for the filling pipes 12 on the left hand side of Figure 1 and for those at the right hand side.As shown, the twin funnel 80 is carried below the reel assembly 83 by means of a slide 84 and a vertical pivot 85, so that either of the funnels 81 and 82 can be brought to the centre line of the reel assembly 83 and therefore above the manhole 86 of a prepositioned tank car 87.

The filling pipes 12 are connected so that pipes discharging black oil use a selected one of the funnels 81, 82 so that the black oil pipes and the white oil pipes are segregated and contamination of the other funnel and the pipes using it cannot occur.

Other methods of mounting the twin funnel 80 to bring either funnel into registration with the predetermined position of the manhole 86 may be - employed. Whatever method is adopted, the required displacement of the twin funnel may be effected automatically whenever change over from one funnel to the other occurs. The mechanism for doing so may be similar in function to that described for operating the drip-tray 52.

Claims (13)

1. Tanker filling apparatus comprising a filling pipe, means for lowering and retracting the pipe to introduce and withdraw the lower end of the pipe into or from a tank, and a liquid level detector carried by the filling pipe.

2. Tanker filling apparatus according to claim 1, in which the liquid level detector is arranged to give an electrical response and is connected to control equipment to stop further flow of liquid from the pipe when the detector becomes in contact with the liquid.

3. Tanker filling apparatus according to claim 2, in which the liquid level detector is so positioned that, when the pipe is inserted in a tank, the detector is located at the maximum level to which the tank is to be filled.

4. Tanker filling apparatus according to claim 2, in which the liquid level detector is carried by the filling pipe adjacent its lower end to indicate remotely when that lower end is immersed in liquid discharged from the pipe into the tank.

5. Tanker filling apparatus comprising a guide device which at its upper end is dimensioned to receive any selected one of a number of horizontally spaced and lowerable flexible filling pipes and which is shaped to guide to a common supply position any such pipe that is lowered, at least one of the pipes having a liquid level detector to indicate remotely when the detector is immersed in liquid discharged from the pipe into a receiving tank.

6. Tanker filling apparatus according to any one of the preceding claims, in which the detector is a thermistor.

7. Tanker filling apparatus according to claim 5, in which the guide device comprises a pair of funnels arranged side by side, for receiving and guiding the filling pipes of different sets of such pipes.

8. Tanker filling apparatus according to claim 7, in which the two funnels are secured together to form a unit which is displaceable to bring either funnel to a predetermined position.

9. Tanker filling apparatus according to any one of the preceding claims 5, 7 and 8, in which for each pipe there is a rotatable reel on which the pipe is at least partly carried and which is arranged to be driven to raise or lower the pipe, limit switching means being provided to detect when the reel has been brought to a position corresponding to a fully retracted position of the pipe.

10. Tanker filling apparatus according to any one of claims 5, 7, 8 and 9, in which for each pipe there is a rotatable reel on which the pipe is at least partly carried and which is arranged to be driven to raise and lower the pipe, and there are means for detecting the obstruction of the pipe during loading.

11. Tanker filling apparatus according to claim 10, in which the obstruction detecting means comprise switching means located adjacent the pipe on the reel and arranged to be operated by the pipe should the pipe be displaced away from the reel due to encountering an obstruction.

12. Tanker filling apparatus according to any one of the preceding claims 5 and 7 to 11, in which a drip tray is mounted below the level of the guide device and is movabie between an operative position immediately beneath the lower extremity of the guide device and at least one inoperative position laterally displaced from the operative position, there being a mechanism automatically operated on the movement of a pipe to displace the drip tray to the inoperative position during lowering and to the operative position on raising of the pipe.

13. Tanker filling apparatus substantially as herein described with reference to the accompanying drawings.