Propylene System

[sagittarius]

Dear all,I have designed the R290 system,but I know few things about R1270(propylene) system? Who can help me?things about all parts of the system?
Thanks a lot.
sagittarius

[US Iceman]

Hi sagittarius,

The same principles apply to propylene also. You can use similar equipment for this refrigerant as the propane system you designed before.

As with propane, propylene has some strict requirements for the oil used. Otherwise, the dilution of the oil can cause severe problems with oil viscosity.

[NoNickName]

Yes, I confirm. Propylene and propane are more or less equivalent, and same requirements apply.

[Josip]

Hello,

check here about physical properties of gases, seems they are very close, check about oil:

http://www.praxair.com/praxair.nsf/AllContent/853446D65991A2F78525663300027DF5?OpenDocument&URLMenuBranch=BEC5C73184FDFEC18525706F005926B7

Best regards,

Josip :)

[sagittarius]

Thanks all,I am very glad to read the answers on this sunny morning.Thanks.
But in the system,I don't know if the dry-filter is necessary?In the propane system I don't use this part,I think it is not necessary,but I am wondering that water in the system of propane or propylene will be frozen, won't it?Is it necessary other parts as simillar with R22?

[US Iceman]

If the system:

a) is properly leak tested and evacuated to provide a dry system, and
b) refrigerant grade purity is used you should be OK.

However, I believe you are right. Propane or propylene can carry water.

I never used any refrigerant driers on any of the hydrocarbon systems I designed though. But... We always supplied commissioning sheets stating the evacuation was required.

[sagittarius]

I'm afraid of the ice forming in the throttle.About the oil,I select the special oil for R290 or R1270 of CPI.(company from USA)

[NoNickName]

Propane you shall use is refrigeration grade. Not LPG from the fuel station.

[US Iceman]

If you are using the oil from CPI you are in good shape. This is the same company I used in the past with good success.

I would recommend them for other refrigerants too.

[Josip]

Hi, sagittarius :)

You did not explain what kind of plant is this one with propylene. Are you use it like refrigerant ( ;) , maybe you are looking to retrofit R22) or that is a process plant where you have to extract (and maybe to liquify) propylene.

My friend was working in Russia and in Thiland at petrochemical plants using propylene as refrigerant (Stal screw S57) with some BP fully sintetic oil.

I was working here in one company on process plant with 3 stage reciprocating compressors (Sulzer-Burckhardt Swiss) to extract hydrogen (for butter production) at atmospheric pressure after electrolysis and storage into hp gas tanks (27 bar). We faced some problems regarding water which came from washing unit for electrolyte removal. Unit was equipped with condensing pots but from time to time we have to open piston heads and clean suction and pressure valves. There was not any problem with oil, it was the same type we use for air compressors.

Definitely you have to speak with compressor's manufacturer about oil.

Hope this can help a little.

Best regards,

Josip :)

[US Iceman]

Here is a set of Pressure/temperature curves for R-290, R-1270, & R-22 for others who are new to the use of hydrocarbons as refrigerants.

As you can see, R-22 is very similar to propane and propylene. Although propylene does have a somewhat higher pressure than the other two refrigerants.

This could be helpful at low temperatures to maintain a positive pressure in the evaporators. However, you also need to check the required mass flow and volume flow for the desired cooling capacity to see the impact of the refrigerant selected for the system.

[Peter_1]

I wonder what will happen if both refrigerants can carry water in a solution and where the temeprature drops in a small orifice?

[US Iceman]

Peter, you are correct. If water was present, ice would form at the expansion device if the outlet pressure was below the equivalent of 0C.

I wish I knew the right answer to this question, but I am not sure of the water solubility with hydrocarbons.

Perhaps Johnny Rod can answer this puzzle?

[sagittarius]

The R1270 system I'm designing is used for the ethylene cracking gas separation process plant.R1270 used as refrigerant.As same as
My friend was working in Russia and in Thiland at petrochemical plants using propylene as refrigerant (Stal screw S57) with some BP fully sintetic oil.
conditioning.But I use the twin screw compressor unit.I don't design the total process system,only the refrigeration section.
Thank you,Josip.I know the material compatibility for R290 and R1270 etc.The files is very useful for me.I have selected the Buna-N for R290,it is not suit for R1270.From the sheet only Viton can be selected.Not same as R22 used,is it?

[sagittarius]

Besides the above puzzle, I have the same thinking to the ammonia system.The present water in the R717 system maybe cause the same trouble,don't it?But in the R717 system there isn't filter-dryer.What happend?
solubility of water with refrigerants?

[US Iceman]

The present water in the R717 system maybe cause the same trouble, don't it? But in the R717 system there isn't filter-dryer. What happened?


Ammonia is hygroscopic. It will absorb water just like a drier will. The ammonia will continue to absorb water until it reaches a saturated point. As the ammonia continues to absorb water the pressure/temperature relationship is changed. You have to run lower and lower evaporating pressures to obtain the same temperature without the water being present.

Driers are available for ammonia, but not normally used.

[Josip]

Hi, sagittarius


The R1270 system I'm designing is used for the ethylene cracking gas separation process plant.R1270 used as refrigerant.As same as conditioning.But I use the twin screw compressor unit.I don't design the total process system,only the refrigeration section.
Thank you,Josip.I know the material compatibility for R290 and R1270 etc.The files is very useful for me.I have selected the Buna-N for R290,it is not suit for R1270.From the sheet only Viton can be selected.Not same as R22 used,is it?

I'm not sure, but using buna, viton or other depend more on used oil. I believe if you ask manufacturer to use compressor with propylene and they confirm then you should not have any problem regarding O-rings and gaskets on compresssor.


Besides the above puzzle, I have the same thinking to the ammonia system.The present water in the R717 system maybe cause the same trouble,don't it?But in the R717 system there isn't filter-dryer.What happend?
solubility of water with refrigerants?

You can ask about propylene purity and accordingly install or not additional drier or whatever.

But I think the same as NoNickName, what is normal. No need to use sh't and after to cry ;)


Propane you shall use is refrigeration grade. Not LPG from the fuel station.

As far as I remember compressor unit was the same execution like for ammonia ref plant. Stal S57 is also twin screw compressor but today out of production.

Best regards,

Josip :)

[sagittarius]

Tell me more special things,those should be paid attention to during desinging and running the propylene system?

[Josip]

Hi, sagittarius


Tell me more special things,those should be paid attention to during desinging and running the propylene system?

What do you mean with more special things?

Best regards,

Josip :)

[NoNickName]

I'm also interested in designing systems with R290, but sources of components are scarce. Where do I find common refrigeration components suitable for R290. My usual suppliers are not of any help, or don't care at best.

[US Iceman]

Hi NoNickName,

What are you looking for? Any electrical component would of course have to be intrinsically safe for the area classification.

If it is for pressure regulators, etc. with non-electrical devices that is a different story.

Let me know what your requirements are and maybe I can find some information for you.

[Josip]

Hi,

regarding execution of unit working with R290, it must be equipped with electronical and electrical devices in explosion proof housing i.e. for petrochemical standards.

Recently we made one installation in one similar factory here and all protection was designed by engineers from that company (production of ammonia and fertilizers).

Unbeliveable story until we came to the end :eek: but we must follow the rules, no other way.

Best regards,

Josip :)

[US Iceman]

...it must be equipped with electronical and electrical devices in explosion proof housing

Areas requiring explosion proof devices can be solved in several ways depending on the insurance requirements in some cases. I have worked on several systems where the customers insurance would allow the use of a NEMA-4 (water-tight) "X" (corrosion resistant, i.e., stainless steel) purged control box.

The purging was done with nitrogen and contained a differential pressure switch that maintained the control box at a slight positive pressure to resist the entrance of flammable vapors.

All conduits were run in heavy wall conduit, not the thin wall stuff. The conduits at the control box had what we called "pour off's".

The pour off's were a solid seal after the wires had be pulled and checked. This provided a vapor tight seal in the conduit and also prevented the entrance of flammable vapors and contained the purge.

All other electrical devices were constructed for the atmosphere just like any other conduit fitting for this area classification.

None of this is cheap!!! And I agree with josip... the standards used on this are VERY strict.

[NoNickName]

Electrical and electronic components are non-issue. I can find them.
The problem is with the refrigeration components, like TXV, solenoid valves, filters, etc. certified in group G1 of PED directive.
Thanks for your offer US Iceman.

[Josip]

Hi, NoNickName

Couple of months before I got request to find some manufacturers dealing with explosion proof A/C units for one petrochemical company.

Here are some links I found:

http://www.marcclimatic.com/products/splitsystems.htm
http://brooklynsevere.com/
http://www.iscsales.com/products/AC/electrical_data_explosion_proof.html
http://www.severeduty.com/catalog.html
http://www.explosionproof.net/window.html
http://www.nsls.bnl.gov/newsroom/publications/manuals/prm/LS-ESH-PRM-1.2.0.html

Hope this is of some help,

Best regards,

Josip :)

[NoNickName]

Thanks Josip, but we are producers, not resellers, so I'm interested in sources of components, not in equipment.

[Josip]

Hi, NoNickName :)


Thanks Josip, but we are producers, not resellers, so I'm interested in sources of components, not in equipment.

I know that :) but my intention was to give you some basic info where you can start with research. Only what I remeber Danfoss produce(d) explosion proof pressure transmitters EMP2.

I must admit that field is not my playground. I was working in such places but playing only with compressor (start up, adjustments) nothing related with explosion proof execution of units.

My working area is mostly in normal installation surroundings without explosion proof requirements.

Best regards,

Josip :)

[NoNickName]

I don't even need explosion proof components. Those are easy to find, and not even always required. For example fans do not need to be explosion proof, for air cooled chillers, because the 20% of LFL (lower flammability limit), will never be reached in open space.
I just need PED G1 certified refrigeration components.

[BESC5240]

I'm also interested in designing systems with R290, but sources of components are scarce. Where do I find common refrigeration components suitable for R290. My usual suppliers are not of any help, or don't care at best.
Hi NoNickName,
I don't know if Danfoss is one of your regular suppliers, but they have all kind of components for hydrocarbons (R600, R600a, R290, R1270 and R170):
thermostatic expansion valves TUBE, TCBE and TRE
solenoid valves EVRE
pressure switches KPE, MPE
check valves NRVE, NRVHE
sight glass SGIE, SGNE
filter driers DCLE
pressure transmitters MBS
....etc

[Peter_1]

I have a friend who's a teacher HVAC/R and he once converted a set-up to R-290.

He said that the properties were similar to those of the old R12, so very similar to R134a.

In the beginning days of R134a, we used our old R12 TEV's for R134a installations and this worked fine.

We once had an eutectic plate who failed. We had a small leak at the place where the tube entered the plate and teh plate was blown doubel it's size due to the expanduing refrigerant in the plate.

The plate was removed and they wanted to know where the leak was. They opened it with a grinder and as soon they went through the plate, it exploded. The person who did this had to be carried to the hospital.
What happened: the client had a leak and to save costs, a DIY he knew had add gass in it several months before. He added propane in it and this worked fine.

[NoNickName]

Hi NoNickName,
I don't know if Danfoss is one of your regular suppliers, but they have all kind of components for hydrocarbons (R600, R600a, R290, R1270 and R170):
thermostatic expansion valves TUBE, TCBE and TRE
solenoid valves EVRE
pressure switches KPE, MPE
check valves NRVE, NRVHE
sight glass SGIE, SGNE
filter driers DCLE
pressure transmitters MBS
....etc

It was, but then we parted because of the TUBE which are built in Mexico and the early Adapkool with impulse EXV. We were not satisfied with these two ranges of products and we moved to Alco.
Thanks for the heads up.

[sagittarius]

Thanks all,I am absent to deal with many things recently.
Back here today,it's so many persons with me,it's my pleasure.
I am just same as NoNickName ,maybe.I want to find some auxiliary parts for my designing R290 ro R1270 system.The products of Danfoss titled above maybe don't provide in China.Maybe some of products did so.(US Iceman knew this matter.Thank you US Iceman ,I have selected the Magnatrol Float Level Controler.refer to thread "some questions of the Propane system")
For R290 system,I used the Hansen's products(solenoid valve,stop valve,filter,regulator valve,etc.) at last.There is a qustion with the valve provider,that is the capacity of refrigeration system.Sometime they can't provide the heavy duty valve.

[sagittarius]

Hi,Josip.The material of seal parts, such as O ring, gasket,is relation to only with oil?But the data from praxair ,different elastomers with the refrigerants.What's the matter?

[Josip]

Hi, sagittarius :)


Hi,Josip.The material of seal parts, such as O ring, gasket,is relation to only with oil?But the data from praxair ,different elastomers with the refrigerants.What's the matter?

Yes and no ;)

We have to check compatibility of our O-ring or gasket material in more ways; first with gas we intend to use (propylene), then with oils we can use with our gas (mineral, sintetic) and then with working conditions (high-low temp, high-low press) to check the strenght under different temperatures and pressures.

Sometimes you can not use any soft gasket for flange connection just metal to metal (conical shape) flanges.

Maybe you are worrying too much ;) if you want to design your project using propylene you should get approval from compressor manufacturer for compressor and from other manufacturers for other parts. I think the best way is to request an offer according to your needs.

But...if you are going to make design, construction and manufacturing by yourself that is another story, you must start from begining, welcome to the nowhere ;)

Please check here something more about:

http://o-ring.info/en/home/

and then on the same page go to basic elastomers

http://o-ring.info/en/basic-elastomers/

http://o-ring.info/downloads/en/technical%20manual/Basic%20Elastomers%20-%20Overview.pdf
http://o-ring.info/downloads/en/technical%20manual/Basic%20Elastomers%20-%20Chemical%20and%20Physical%20Tables.pdf

or here

http://www.dupontelastomers.com/Products/kalrez/kalrez.asp

Hope this will help a little,

Best regards,

Josip :)

[US Iceman]

That is good advice Josip.

Especially this:


But...if you are going to make design, construction and manufacturing by yourself that is another story, you must start from beginning, welcome to the nowhere

If you are doing this sagittarius then you have to check and verify EVERYTHING.

Great links posted by Josip.

[sagittarius]

Yes,that my job.But I am lack of experience in this region,I graduate from the major of refrigeration.I will do my best to reserch and designing.
I admire your self-giving spirits.This is a total sharing forum.
Thanks all,thanks RE.
sagittarius

[kasperDK]

Hi all

in denmark,a new law efected at jan 2007,says no more than 10kg. chage HFC pr. unit, (CFC, HCFC is not legal) so, Some companis have standart HC Chillers in ther product program, See Bundgaard Koleteknik Using R290 range 50-300kw or York koleteknikes Bonus unit using R1270 all PED-standart (en-378).

[US Iceman]

Hi kasperDK,

What refrigerant are they using when the capacity requirement is greater than 300 kW? Multiple units of smaller capacity???

Thanks.

Best Regards,
US Iceman

[kasperDK]

We use ammonia or multiple units ,normaly we say above 160kw R717 is more economic to builde/run this is for chillers 6/12 gr C,

for special low temp applications, we use (world lagest -55 gr Rum) think it is R170 ethan or R1150 ethylen , we use to use R23 for this application.

[TXiceman]

Just as a point of reference, we regularly build hc (hydrocarbon) based refrigeration sytems using recips, screws and centrifugal compressors. We address the electrical requirement of the U.S. as well as Europe, China and UAE.

We have another division that deals with XP (explosion proof) air conditioning units for off shore/marine applications.

It can easily be done, but it is not cheap.

Ken

[sagittarius]

Hi, I am missing for a long time.
I remember this home wherever and whenever.
In China, propylene refrigeration systems are used mostly in Petro and Chemical Industry .

[TXiceman]

Yes, water can be a problem in hydrocarbon systems. I would never operate a hydrocarbon system in a vacuum.

The water will remain free and will show up in two places. One is the compressor oil which will give you an apparent plugged oil filter as the paper fibers will swell due to the water. You can use a special fiberglass oil filter element.

The other problem with water in the system is it will freeze when you cross a throttling device and drop below 32 dF (0 dC).

I have designed systems fro hydrocarbons both with and without filter drier cores. Some were full flow driers and others were bypass type.

If the system is properly evacuated and dehydrated, water will not be a problem. However, if you introduce some water into the system due to poor maintenance procedures, you can have problems.

Ken

[sagittarius]

I don't know who can provide the suitble filter drier,solenoid valve,thermostatic Expansion Valve.which company can do?

[TXiceman]

For a filter drier I have used Sporlan (with steel pipe connections). I do not recommend using a Thermal expansion valve on hydrocarbons. If you must, go with Sporlan and get them to make a selection. As for solenoids, you will need to get one that is a Class 1, Group C and D, Division 2 area classification. Try Parker (Refrigerating Specialities) or Asco. I know they can meet the US explosion proof requirements, not sure about PRC.

I hae only worked with one or two DX hydrocarbon systems, as most use a flooded design evaporator. If you go DX, set your TXV super heat for 18 to 20 dF superheat. I also like ot use a suction/liquid heat exchanger to insure the suction is dry. A little hydrocarbon liquid will really mess up a compressor in short order. If your compressor is a recip, plan to rn with the crankcase heaters on full time to keep the oil warm and the hydrocarbon driven out. Probably ahve to do the same with a screw compressor. Hydrocarbon refrigerants do not superheat a lot when compresed, so you really need t watch the oil. You will have to run a poly-glycol based lube oil as recommended by the compressor manufacturer.

Good luck.

Ken

[US Iceman]

From what I remember propylene (R-1270) has very high dilution rates with oil, so it is very important to keep the oil warm enough. (which is what TXiceman is saying)

If the crankcase (for a recip) or the oil separator (for a screw) pressure and temperature relationship are known, you can look at the dilution curves to see the impact on the amount of dilution to maintain the minimum required oil viscosity (by the compressor manufacturer).

Don't be surprised to see a high viscosity oil recommended. By the time the oil and refrigerant have stablized, the oil will have thinned out to a much lower viscosity.

Hydrocarbon systems are not very forgiving of mistakes.

[sagittarius]

I am confused.Those company you all stated, parker,spoland,danfoss etc,have still not replied me whether they can do. I wanna use the TXv ,drier filter,solenoid to the economic exchanger(for screw compressor).But Danfoss dont recommended in hydrocarbon system,parker have not reply clearly.I.....

[TXiceman]

It is sad to note that Sporlan has lost most of it's expertise in using TXV's on hydrocarbon refrigerants. If I remember correctly, is does require a special bulb charge...but I don't remember the charge.

For Solenoids and pressure regulators, you night try Hansen.

Since this is on a screw compressor, what is the capacity and temperature? I did not spot it in the past post on this thread.

With a DX design, you need to be very concerned with proper tube velocities and possible multiple circuiting to insure oil return to the compressor.

The synthetic oils used with hydrocarbons do dilute and are very viscous at lower temperatures. You do need to look into the dilution. Best oils for these applications come from CPI Engineering in the USA.

Ken

[sagittarius]

Thank you TXiceman.
Things seem badly to me.'Cause all the parts for the R1270 system are difficult to select.TXV,Solenoid,Drier filter.....Danfoss,Parker(spolan is a subcompany to Parker),Hansen cant provide suitble parts for R1270.I am just looking for another way .
The system is a large one. Capacity is Te=-32C,Qe=4000kw;Te=-15C,Qe=2184kw.I have selected 2 sets unit with volume 7240 m3/h for first case,1 set unit with volume 4700m3/h.
You are right, I use the CPI synthetic oil.Now CPI haven't decided which type oil better.CP4600-68 or CP1507-100?waiting for the decision from CPI.

With a DX design, you need to be very concerned with proper tube velocities and possible multiple circuiting to insure oil return to the compressor.
what suggestion for this?
sagittarius

[US Iceman]

Capacity is Te=-32C, Qe=4000kw


4000 kW @ -32C evaporating temperature using TXV's???:eek:

How many evaporators do you have on this system and what are the capacities of each?

Since you are using a hydrocarbon refrigerant, the electrical devices will have to be rated for explosion proof atmospheres. Hansen may not allow the use of their components in this duty if they are aware of the area classification.

On a system this large you may have to use multiple liquid line driers to acheive a suitable capacity...

[TXiceman]

4000KW is too large for DX control unless you have severla smaller evaps and I don't like to use D control this low in temperature.

You really need to be looking at a conventional flooded design and oil stills to get the oil back.

Ken

[sagittarius]

Aha
This project has been done now, it running well.
Not a DX control, it uses 8 flooded evaporators.
This system is consist of 4 compressors, 2 evaporative condensors, 2 liquid receivers, and 8 evaporators.
Results as following:
O ring is Viton.
Don't use drier-filter.
......
Thanks all.
This forum is great to me!

[Josip]

Hi, sagittarius :)


Aha
This project has been done now, it running well.
Not a DX control, it uses 8 flooded evaporators.
This system is consist of 4 compressors, 2 evaporative condensors, 2 liquid receivers, and 8 evaporators.
Results as following:
O ring is Viton.
Don't use drier-filter.
......
Thanks all.
This forum is great to me!

Nice to hear that.:)

Can you tell us something more about....type of compressors/control, evaporators, condensers, etc.....some scheme, photo...;)

Best regards, Josip :)

[sagittarius]

Ok. I learned a lots from this forum,it helps me to design the system.
comp.:V35,(equivalet to WRV510132 HOWDEN) V32,(equivalet to WRV321165 HOWDEN),each 2sets,with economizers,local manufacture
evaporative condensors:CXV-T1584,BAC
liquid tank: volumn 20m^3, 2sets
evaporators: 8sets,flooded type, float valve control

[TXiceman]

I have a friend who's a teacher HVAC/R and he once converted a set-up to R-290.

He said that the properties were similar to those of the old R12, so very similar to R134a.

.

I have designed several propane and propylene refrigeration systems using twin rotor screws by Howden and Mycom as well as Mycom and Vilter recip compressors. Even did a couple with carrier 5H compressors. The properties are no where near like R-12. Look at the pressures, temperatures and specific volumes. They are more like R-22.

I hope your old instructor was teaching something other than refrigeration.

You can use mineral oils, but synthetics work much better due to solubility with the refrigerant.

Both R-290 and R-1270 are considered high pressure refrigerants and R-12 and R-134a are considered medium pressure refrigerants.

I even have one iso-butane (R-600a) system with three 700HP GEA compressors. R-600a is more like R-11 in its characteristics. With R-600a you have to be very careful with the suction and have a minimum of 40 dF suction superheat as the constant entropy lines go back into the saturation dome on the PH chart.

Hydrocarbons are excellent refrigerants in certain applications. You have to watch the oil return issues, liquid carry over is very critical and all of the safety issues as it is an explosive. As a minimum, most agencies will require it to be what the US calls Class 1 Division 2 area classification. Class 1 Division 1 is fully explosion proof.

I have used Sporlan driers in hydrocarbon systems to make sure you capture any moisture. They make a core thast is compatible with HC's. If you are operating above freezing, water will not bother the control valves, but will effect the oil system on the screw compressors. The oil filters are typically a paper element and a 15 micron filter will swell the paper elements and give you a high filter pressure drop and eventually cause an oil pressure related shut down.

[sagittarius]

The system I have designed is running well.
I wanna know other way to charging refrigerants.I charged propelene by this way.
First filling 5bar Nitrogen gas in receiver,then charging propelene, to enough quantities,running the system,purging the N2 by the air separation parts.
This way is to provide the propelene flash in the normal pressure receiver.

[Josip]

Hi, sagittarius :)


The system I have designed is running well.
I wanna know other way to charging refrigerants.I charged propelene by this way.
First filling 5bar Nitrogen gas in receiver,then charging propelene, to enough quantities,running the system,purging the N2 by the air separation parts.
This way is to provide the propelene flash in the normal pressure receiver.

:confused::confused: why nitrogen, it was possible to charge gaseous propylene maybe .... what will happen if you fill propylene in empty receiver..... at 5 bar Te is -5*C at 0 bar -60*C what is dangerous for receiver material...but charging slowly you will soon rise pressure.... or maybe there are some other reasons.... please, explain

Best regards, Josip :)

[TXiceman]

If you first charge with nitrogen as a pressure test, I next blow the low points using the N2 pressure to sweep them clear of trash. N2 is an inert and has to be cleared from the system. Next problem is the moisture in the system. You need to pull a good vacuum to clear the moisture or it will freeze in the first expansion device you have.

As for the materials of the receiver, it should be very small as the system is generally critically charged on the low temp system of a cascade.

When you break the vacuum on a system, you should not break it with liquid into a high pressure receiver. Break it with vapor until you have a positive pressure then feed some liquid in a small amount or equalize it with the charging tank and pump the liquid at ambient temperature to the receiver.

But charging the low side of a cascade is a bit tricky fro the uneducated.

Ken

[sagittarius]

To avoid propylene instantaneous flash in the vacuum receiver,I can charge liquid propylene to the receiver.The pressure of being charged propylene into receiver is about 8bar.Another reason is that I am afraid of instant flash causing exploding.
After charged the propylene, purging N2 by air seperator in the system.
Txiceman said is for the cascade system?thanks a lot. I've desigened my first cascade system recently,it will be first started up. I need some help about the cascade system.

[The MG Pony]

with any HC, no air = explosion impossible, after all even the oil we use will burn if there is air! So why worry about the HC?!?!?!

Treat hydrocarbons just like any other refrigerant, but keeping in mind they are slightly more flammible then standerd refrigerants (Which are infact quite capable of burning and exploding).

Pull the standerd 500 micron vacuum (If you are like me lower, much lower, for an HC systems I let it go to 200micron) then charge liquid directly to the receiver, then finnish off via low side adjusting. There is no need to mess around with N2 and such, far more important things to be worried about!


After seeing propylens curves compared to R-290 & R-22 I think I'll be procuring some! looks verry nice.

[The MG Pony]

Propane you shall use is refrigeration grade. Not LPG from the fuel station.

Odd you say this as for majourity of my "for fun" builds use just that, interestingly enough I find no performance differances, other then the scenting agent needs to be scrubed out first. Once scrubed it works fine.

[nike123]

I taught that LPG is mixture of propane and butane?

[The MG Pony]

Not here, propane is suposed to be propane, and Butane butan, given there is some of each mixed in as impurities how ever purity is as such if I use bbq grade R-290 it will match the PT for R-290 flawlesly, so not enough to degrade performance in any serious matter, in other places I don't know.

[TXiceman]

There are several grades of propane and the refrigerant grade is not the purest. HD-5 is a grade you often see in the refineries and chemical plants. It has some heavy end and light end products as well as some free water.

The heavy products will settle in the evaporator and the light ends will tend to concentrate in the condenser and raise the partial pressure which causes an increased discharge pressure for the compressor. You can vent the light end concentrations and bring the condensing properties back pretty close to pure propane.

BBQ or bottled propane has some butane as well as some other HC products. I don't remember the mixture.

Ken

[sagittarius]

There is a new question about this system.
Looking back recently,I think how to handle the emergency for the r1270 (hc etc.)system. I have set the emergency port on the bottom of liquid receiver tank.But the R1270 liquid where to go?
To ammonia we can purge it with water to the drainage.To R1270 directly to the torch? It maybe not a good idea.R1270 liquid may expand and become gas,ice forming on the port of emergency pipe.what to do?

[TXiceman]

Relieving liquids to flare is a different ball game than vapor. You can't put the liquid directly to flare. Normally you have to put the liquids to a vaporizer or to a flare knock out drum.

You need to be sure that you design the liquid piping to meet the temperature requirements for the local code requirements fro temperature. If you design per ASME VII section UCS.66, you can derate the pipe for coincident pressure at the lower temperatures. Some allow this some do not. In any case if you drop the liquid to atmospheric pressure, R-1270 will be about -54 dF. The K.O. drum has to be designed fro the lower temperature and pressure as well.

Usually the drum will have a heating source, electric or steam to vaporize the propylene as it is vaporized.

It would be better to send only the vapors to the flare.

Ken

[sagittarius]

Thanks!
It's a good idea.The knock out drum with heating source at the outlet of liquid emergency port.But this drum maybe a bigger one.Need some mist eliminating device?

[TXiceman]

You need to have a drum large enough to catch the largest liquid slug you would expect. Some have a mist eliminator and most do not.

The project I am currently working on has a flare to flare off waste on an FPSO. The drum is about 14' in diameter and 30' long and has a large electric heater in the boot.

ken

[yadi]

dear all,
we have problem of my system after upgrading refrigerant from R22 to propylene and change the chiller, economizer,condenser, we use screw compressor, refrigerant propylene and oil cpi-1507, but of the system if the temperature discharge low and temperature chiller very low and the system always oil carry over.why oil carry over?

[TXiceman]

Yadi, what temperature are you running at the evaporator. Tyep compressor and oil separator.

If you are carrying excessive oil, you need to look at several issues:
excessive liquid refrigerant carry over into the suction.
Low condensing pressure,
poorly designed oil separator
Oil separator elements are "blown" and need replacing.
Wrong oil, incorrect vapor (too low) pressure with refrigerant used.

Any one of these can contribute to excessive oil carry over.

Ken

[Carlos Barrantes]

The original question was about system with r290 ( PROPANE ) and the whole conversation has tried the Propylene systems ( r 1270) . What is the reason ?

[reach1e]

Hi Saggitarius,

Did you managed to find a supplier for Propylene Thermal Expansion Valve?

Our local Sporlan and Danfoss supplier said they cannot supply any that is compatible for propylene.

[sagittarius]

Hi, Reach1e:

I didn't find the exact propylene TX valves finally. I used an air-operated valve.
For HC refrigerant it's not easy to find the TXV.
I used Sporland TXV for R290 ever.

Sagittarius

[reach1e]

Hi Sagittarius, may I know if you've oil filter in your system?

If so, who is the supplier? and anything special I need to look out for?

This is because I'm looking for a new oil filter for our propylene compressor .
Thanks

[sagittarius]

Hi Sagittarius, may I know if you've oil filter in your system?

If so, who is the supplier? and anything special I need to look out for?


Yes. There are two parallel oil filters in the oil system. The oil filte is similar with ***** application. But there are a bit difference that the rubber material ( O ring or sealing ) is HNBR suitable with PAG. The cartridge is fabric about 20um filter efficiency.

The filter body is carbon steel.

[TXiceman]

I have used Sporlan TXV's in propane and propylene systems. DO NOT depend on the local Sporlan distributor. Put in a call to the Sporlan factory and talk to the older rating engineers.

Ken

[Deep231]

Hi All,

I am new to this forum and look forward to valuable inputs from all the members.

I am looking for the replacement of TXV operating with Propylene as refrigerant. Unfortuantely, the local supplier (Sporlan) has shown inability to provide TXV for this service.

Is there any other supplier who deals in the prylene system components. Will appreaciate if I can get some directions on this.

Thank You!

[TXiceman]

You need to go back to the Sporlan factory for better suport. I am beginning to think that the local distributors must be hiring Wal Mart rejects.

Ken