Got a problem pointed out to me today. Truckers fill up then park up ready to leave. They normally fill up at night when they finish and it's cold, then leave in the morning when it's warmer and their tachograph says go for it. The warmer fuel takes up more space (p1/v1t1 = p2/v2t2 or whatever it is) and often spills onto the yard they're parked in. How about fitting a bladder in the fuel tank that inflates slightly (base the calculations for expansion on the temperature range for the uk average over 24 hours.) when the tanks empty and deflates due to the weight while it's being filled. Exists? good/dumb idea? Just thinking about projects for when I carry on with me mech eng degree again in september. (permanent job means able to afford interests again) Seemed a pretty miscellaneous technical question so stuck it here.
Pikey Proof tanks would be a good plan Decent anti tamper caps... Anti syphon etc I've always found my Diesel to be luke warm if topping up at Night due to return pipes... Most of the spills I guess will be down to **** fuel caps... Lot of Trucks I've used would lose diesel during the day or night via the caps... In use or fuelled up and parked..... Made no difference on -10C early starts there would still be Diesel on the floor.
how about not filling right to the top of the filler opening! good idea but to quantify things you need to calc the thermal expansion/contraction of the fuel and the movement in mm up and down the tank for a typical cold/warm cycle from my point of view the diesel would be warmer at 9pm at night than at 6am in the morning just my 2ps worth - ya know just like a swimming pool is warmer at night than in the morn...... the thermal expansion/contraction you mention does go on - i used to work on jet aircraft and the hydraulic systems on a cold day would indicate 4.0 litres and 4.4 litres in the two systems - after flying when the oil is much warmer that a warm day they would point to 4.3/4.7... this is from one extreme -5degress to say about 70 degrees.
Is it not more likely the cause of the leaks is due to the small amount of air left in the tank expanding slightly, pushing the fuel out rather than the expansion of the fuel itself? Cerips. I remember that equation from when I was on "bubble watch duty". Whilst the oil rigs were drilling, I would park the ROV on the seabed and watch for bubbles as they drilled! The thing is, if you get a bubble the size of a car at 450m , by the time that makes it to the surface the rig would fall into the hole due to the expansion of the gas as the pressure decreases nearer the surface!
Patent away mate, I've already applied for the important one. It replaces the modem noise on a fax machine with power chords.
wont the bladder stretch with the weight of say 300litres before if expands due to heat? also wagon tanks are baffled(modern ones anyway)which would complicate things. I have made this mistake myself, its amazing how much fuel expands in a tank. how about us truckers get some brains and not over fill!
Good work - does it play Spinal Tap if you turn the fax machine up to 11? I reckon there's some mileage in your idea - start by checking the expansion rate of diesel according to temp, then think of ideas to prevent the spillage. They're very touchy about fuel spills (even evaporation from the pump) in the states, so it could well have a big market. Maybe there's a valve in the tank that stops you filling more than 90% full (or something like that) Maybe there's an extra expansion chamber/pipe near the top of the tank that doesn't fast fill from the pump, so when the slow expansion happens, it fills the chamber rather than going out of the filler. One way valves could let the diesel back into the main tank as the level drops.
Reckon you'd be onto a winner if it was drill-proof. Popular pikey method of getting fuel out of newer tanks - battery drill. Most yard diesel spills IME seem to be dopey drivers that lock the diesel nozzle on and go get a cuppa while the nozzle falls out of the tank. In all reality you probably want to start by looking at the current mechanism of stopping the fuel flow when the tank is 'full' - a tank with a long feeder pipe (like in your car) will be totally full and fuel halfway up the filler neck when it locks off. A truck tank typically has a very short, or no neck at all, meaning the end of the nozzle is actually in the volume of the tank, thus when the fuel touches the nozzle there's probably a good air volume left in the tank unless the operator gets clever and withdraws the nozzle whilst filling. Do you have to consider the marketability of this product too? Many fleet operator will probably be loathed to spend money on a solution when it can be solved by managing the problem differently (i.e. operator procedures).
Seems to be 2 different problems spills and theft but y've given me an idea. I'll think about why it won't work on me nightshift tonight. I find this interesting because it's in a huge tank of fuel so you can't just got for the easy throw electronics at it.
Figured something out solves both problems. Just need to kidnap a materials engineer for a few days. Can anyone point to cost of a drilled tank? New tank, lost fuel, lost timed delivery, wages etc
A smidge over 500litre Aluminium Tank from DAF comes in at circa 1100. Some of the Euro boys are running units that have tanks totalling circa 1400litre tanks. Lot of the tanks are plastic.. Never had one got at other than the caps so no idea at cost. I know a locking cap from Ivecos is 40odd quid... Ours were hit 3-4 times one after the other on 3 Trucks at a time.. Soon adds up @ 70ish a go for fuel *small tank 7.5tonners* + caps Fuel cost = Pump price minus a couple of pence... Most will be on a fixed pice agreed with fuel card company for the week. Downtime etc your looking at callout+new tank+fuel.....prices could vary massively.. depends where you are aswell I guess.. 25mins from a Main Dealer or parked up outside some skanky Romanian factory or beyond. The loss of earnings would vary again depending what kind of work the truck is on... Some of the big Supermarket RDCS are very big on you have to be on time no ifs no buts... Miss your slot and your ****ed off down the line or worse load rejected... Your then into waiting time etc and if your loads rejected you wont be picking up a return load nearby to make it pay both ways as you'll be taking the load back... Again... Your parked up for the night in Asford Truckstop waiting for the dash to the boat for 3am and you wake up and your fuels gone... You wont be on your 3AM boat... Your load wont be delivered on time and the return load of Oranges out of Spain could be on someone elses truck.
One solution to the tank drilling is to make it double-skinned - the second skin preferably deeper than the average drill bit. Fill the cavity between with some kinda expanding foam stuff that'll essentially repair any puncture hole - bit like what they do with the fuel tanks of fighter 'planes. Only downside, apart from the added cost would be the reduced capacity of an equivalent size tank.
Simlar to what I was thinking. Rubber inner skin possible to be replaced at roadside. Pressure valves with an air pocket leading back to filler neck to create the space to allow for fuel expansion. Putting filler cap on releases air pocket valve allowing the room for fuel to expand. Air comes from outside the rubber skin into the air pocket pushed by the fuel entering the inside of the skin and filling the tank. Rubber sheets inside the skin to recreate the baffles in a metal tank reduce cost of aluminium tank they are tensioned by the fuel pushing against the side of the skin. Was thinking about an outer layer for it that contaminates and ruins the diesel when drilled and a non return valve/ mesh filter like in the new fords to stop fuel escaping/ being syphoned. Position that on an internal filler neck to the rubber skin so fuel can reach above the neck of the filler to the fuel tank but not flow back out. Conclusion. 1) Night shifts are dull. 2) Thinking about random problems helps pass the time 3) I should sign up for the module on polymers.
