A question regarding conveyor meters

[6Havok9]

Hello dupes and dupettes. I have a problem with conveyor meters. Actually, more than one. It's complicated.

So I ask you seasoned engineers: is it possible to have a conveyor meter act like a valve without recurring to an overly bulky system? By "act like a valve" I mean: the conveyor line must always output the desired amount in packet weight per second. This is easily done when dividing an incoming 20 kg packet into smaller, perfectly divisible packets: like 10 kg, 5 kg, 2500g, and so on. But.. what about thirds of a packet?

To be more specific on the application of this thingamajig, I'm working on this thing, carried by the inspiration @NurdRage's OSHA's Revenge blessed me with:

It's a 10 kg/s sour gas boiler with sulfur reclamation, with minimal automation. It's the first time I try to devise a compact boiler project, I used to build a "well, it works" thing and called it a day. But this thing, it just works: its equilibrium is based on the properties of construction materials. Shoutout to radiant cobalt and radiant lead! And dirt. Thermium is only used in the aquatuners. BUT...

THE SULFUR. How am I supposed to send out the sulfur as "nice" (ugh) 3.3333- packets? I had to clamp the output to 2500 grams per packet via a meter valve, with a timer sensor controlling the loader. 7 seconds red, 1 green, ending up with a 20 kg packet every 8 seconds, split in 8 baskets after the meter.

The problem is that this piece of junk won't split 20 kg packets in thirds. There'll be the mcg straggler screwing everything up. And if I set the meter to something like 3.3----4, I end up with these leftover, increasing in weight packets: 2 grams, 4 grams, and so on. I've tried to reset the meter with a pulse, but packets don't merge in the device like liquids do when entering valves, leaving me with those almost empty baskets clogging everything, or worse, melting!

Allowing a 20 kg lump out every 6 seconds doesn't work, since it cannot be divided into thirds.

It bothers me to leave a quarter of the sulfur production there, but having excessively different packets going through the heat exchanger, combined with the autosweeper working 24/7, bothers me more.

Is there some shamanistic ritual I'm unaware of that can help me, given the limited space I'm working with? Or should I just accept that loss of sulfur as a tribute to the natural gas gods? I don't want to just dump it out and heat it up elsewhere. And I want that cooling power! Meh 

Peace! And packets.

Havok

[JRup]

49 minutes ago, 6Havok9 said:

It bothers me to leave a quarter of the sulfur production there, but having excessively different packets going through the heat exchanger, combined with the autosweeper working 24/7, bothers me more.

Ahh, welcome to the plight of binary numbers. I'd recommend rounding up the sulfur packages so that they meet the numeric "quota". Anyhow, the mcg straggler problem can be avoided if the route the sulfur takes is direct and without loops. Sulfur does not have that much energy to it in order to build a loop worth it.

As for the autosweeper working all the time, a well placed timer sensor could help. A convenient minimal activation time can be 10s; the "off" interval can be adjusted to meet the sulfur production in the chiller section of the sour gas boiler.

 

[wachunga]

The easiest thing is probably to abandon 3.33 kg packets and go with average output. Throttle at the output for one packet every 6 seconds, the exchanger will fill with 20 kg packets but they will move slowly and give an overall flow of 3.33 kg per second. In my experience the heat exchanger doesn't perform as well as with the proper size packets moving per second, but it's not substantially worse and may be good enough for your situation. Test it yourself and see how it plays out. Better would probably be a hybrid approach where you use the splitter to make 10 kg packets and let them out once every 3 seconds. In such a scenario, it's also pretty easy to avoid automation at the output if you so wished. Though automation would allow you to stop output occasionally to keep the exchanger full, since the output is theoretically slightly higher than production or in the case of hiccups. The middle portion of the lower rail represents the heat exchanger section.

In order to get perfect 3.33 kg packets you would have to dump the remnant packets out to get picked up again. Alternately you could do some rail spaghetti shenanigans like the above to get 5 3.33 kg packets from the splitter followed by the 3.35 kg remnant packet. Or 2 3.33 kg packets followed by the 3.34 kg remnant by first splitting to 10 kg and then sending to another splitter. But I doubt it's worth the effort to go that far.

[ZombieDupe]

The conveyor meter confuses me. It says it's meant for letting only  specific amount of a resource through before sending a red signal and stopping or something like that, but it actually only just works to limit itself from 20kg per packet of material to lower like a valve. Did someone get confused during this item's implementation? Sounds like two completely different functionalities and the automation gates don't really work as a result, or am I misunderstanding what's going on with these things?

[wachunga]

Meters can be set for an amount greater than packet size. You can make a system that sends 357 kg of something and then stops until another 357 kg is requested. The thing is that there isn't much reason to do that and since rails don't have valves, you just see people repurposing the meters as valves. I guess they have more utility in the DLC where there may be a reason to periodically send material to another planetoid on demand. In the base game you would just run another rail/pipe line to whatever and have it always be filled, but in the DLC you are limited by having to share the rail/pipe going through the teleporter or your launcher system.

Also I think there are bug reports of meters not reliably sending the amount they are supposed to, which could be another reason why you don't frequently see them being used in their intended function.

[Gurgel]

Meters becomes less confusing if you view them like this: You set an amount _larger_ than 20k, you give it a reset and it lets that amount through before blocking again. It can be used for packages smaller than 20k, but that only works somewhat and really is the job of a valve instead.

Valves will also accumulate smaller packages and essentially have a bit of internal storage. I am not sure Meters are doing that.

[6Havok9]

Thanks for the replies. Since in my situation I have not much space to work with, I've decided to simply use another conveyor loader on a lower priority. Logic is as follows:

Loader #1 is on a timer. I wait for It to be full, then I turn it on. It almost always contains 980 kg or 1000 kg of material, so it always sends out 20 kg packets which get split into smaller packets, resulting in a controlled, continuous flow, ideal for heat exhangers. This controlled flow should match the machine's output as much as possibile.

Loader #2 receives the leftover items after #1 is full. For semplicity, this loader will just try to empty itself. I let the packets merge with the other debris at the end of the line. So I end up with a full 3.3 throughput with very good output temperature control.

Might as well try to put a timer on loader #2, so it doesn't work like crazy.

[ghkbrew]

On 3/5/2022 at 11:26 AM, wachunga said:

In my experience the heat exchanger doesn't perform as well as with the proper size packets moving per second, but it's not substantially worse and may be good enough for your situation.

Theoretically, having a full rail of 20kg packets moving 1 packet / 6s should give you significantly better heat exchange than 3.33kg packets moving at 1 packet/s.  Intuitively, each kg of sulfur spends 6x longer in the heat exchanger to dump it's heat.

My anecdotal experience is consistent with that.  Do you have a setup where it's actually worse?

[6Havok9]

59 minutes ago, ghkbrew said:

Theoretically, having a full rail of 20kg packets moving 1 packet / 6s should give you significantly better heat exchange than 3.33kg packets moving at 1 packet/s.  Intuitively, each kg of sulfur spends 6x longer in the heat exchanger to dump it's heat.

My anecdotal experience is consistent with that.  Do you have a setup where it's actually worse?

EG: this one setup in particular, a sour gas boiler, with no loops in the exchanger.

I want sulfur at room temperature. I send 20 kg packets every 8 seconds in the relatively short exchanger and let it run. I end up with several tons of brutally subzero sulfur.

If I divide those 20 kg in 2500 grams and send one every second and let it run, I end up with several tons of 5/30° C sulfur, depending on my decision to let it out of the exchanger one rail segment earlier or one later.

Sulfur is always created at -163 C° and it stays pretty much at that temperature if left there. Every kg of sulfur spends the same amount of time in the exchanger, regardless of the quantity sent. It must travel X tiles, and it will do so one tile per second. Since no loops here: straight to the exit.

What changes is the size of the packets and, even when running through aluminium tiles, 20 kg packets just say "Nah, I'll stay cold, thank you". They'll even happily take a route through the aquatuner chambers while retaining the ability to flash freeze you to death if you ever touch them.

Meanwhile, 2500 grams packets are having a debate on whether it's better to be immediately eaten by a divergent, or given as fertilizer to a grubfruit plant first to be eaten later.

I could try to make a loop and ditch the straight to the exit idea (not sure I have the space to do so) then compare the same 20 kg packet output, looped some times, to the continuous 2500 grams/sec outflow. But it would introduce a new fluctuating variable in the system, and I'm not sure I want that in this case. Gotta keep that temp in check, I don't like solid methane, nor persistent gas bubbles!

[wachunga]

@ghkbrewI don't recall what I was doing that lead to small packets moving each second being better than large packets moving slowly. It's one of those "best practices" that I've filed away without remembering where it came from. That said, there are so many interdependencies and variables in a heat exchanger that I don't find it at all surprising that some situations perform opposite to my findings as you're saying. I threw together some examples based off a petroleum boiler since that's an easy example. It's different from sulfur in a sour gas boiler, but it should illustrate the principal. Whether this still holds true for sulfur in a boiler is unknown to me!

Crude oil flowing against petroleum. Leftmost is 2.5 kg packets moving each second. Middle is valved at the end so the packets are 10 kg but with a 2.5 kg portion moving each second. Rightmost is one 10 kg packet moving every 4 seconds. Small packets are better, but just slightly.

Replaced the crude with igneous. Leftmost is 5 kg packets moving each second. Middle and rightmost are functionally (and experimentally, yay) the same since rail packets can't merge, one 20 kg packet every 4 seconds. Small packets perform slightly better again.

All the math for conservation of heat works out properly so I don't think we have to worry much about potential bugs here.

 

EDIT:

Was screwing around with a test that is more representative of an actual sour gas boiler.

0.25 kg/s -165C sulfur flowing against 0.758 kg/s 100C sour gas. Left side as 0.25 kg packets every second. Right side as 20 kg packets every 80 seconds. Small packets perform slightly better, going from -165C to 1.2C. Large packets go from -165C to 0.2C. However this difference only translates to 0.1C in the outgoing sour gas, that's pretty meaningless. So I would say go with whatever setup is more convenient or that you find more pleasing for whatever reason. And the save if anyone wants to screw around also: test3.sav