Salt Conveying
P. Gjerde,
The properties and conveying characteristics of salt are similar to those of sugar, with which I have quite some experience.
Both dense-phase and dilute-phase designs can successfully convey salt per the configuration that you provided. Dense-phase does have the advantage of low-velocity conveyance, which will minimize degradation of the salt crystals. The conveying gas should be maintained at a low dew point (even minus 40 degrees) to exclude moisture. A conveying gas needing to be this dry is easier to manage with a closed-loop system design.
Maintaining a dry conveying / storage atmosphere will keep the salt from coating the conveying pipes or caking in the silo.
Kind regards,
Dennis Hauch ■
Re: Conveying Of Salt
Hi Dennis,
I was interested in your comments regarding dry air for pneumatic conveying. A dew point of -40 degrees represents a pretty low humidity gas. Is this normally used for sugar? I wonder could you explain why?
My understanding in the case of salt (NaCl) is that the water adsorption isotherm is almost vertical at around 75 % relative humidity. I would have thought that a reasonable margin below that level would suffice to maintain good handling. Are there some other factors at play here?
Regards,
Peter ■
Salt Conveying
we have conveyed salt at 10 TPH over 75m to a silo in dilute phase for a large detergents manufacturer.
please let us have your application details for us to suggest the parameters
b.velan
www.scorpioengg.com
scorpioengg@vsnl.com ■
Salt Handling
Peter,
In my experience it was necessary to handle the sugar in a dry and inert atmosphere for flowability and process reasons, respectively.
Salt must be kept dry to keep it flowing. A small example, here on the Texas Gulf Coast you will find grains of rice in all the salt shakers in the restaurants, to keep the salt dry. Despite what the isobar says, over time free water can accumulate in the storage bin, on the side walls and in the bottom, especially if the bin is open to the atmosphere.
A closed conveying / storage system is the first step. The second step is the provision of an atmosphere sufficiently dry that even over time the salt will remain dry and free-flowing.
Regards,
Dennis Hauch ■
Conveying Of Salt
In the similar case for a food salt we successfully
used the FLEXOWELL pocket elevator ( white rubber)
having vertical & horizontal sections.
This is a very simple and reliable option for you.
Michael Rivkin ■
Salt Conveying
We can offer you a pn. conveying system.
Please send us your application details.
Regards,
Serby AG / Switzerland
www.serby.com
serby@bluewin.ch ■
Salt Conveying
Mechanical transport will take much less energy!
For example bucket elevator 40 meters and belt conveyor 50 meters will take 15 kW together for 60 tons/hour.
Estimated price excl. erection, ex works in pre assembled parts:
elevator € 50.000 and belt conveyor € 35.000,-
Jur Lommerts
Jansen & Heuning Bulk Handling Systems
The Netherlands
www.jh.nl
jfl@jh.nl
tel: +31 50 3126 448 ■
Conveying Of Salt
In addition to the large energy consumption, the
pneumatic systems are much more "sensitive" to the
quality of material and compressed air.
I'd recommend the pneumatic systems in the case
then there is something preventing using
mechanical systems.
Advantage of the FLEXOWELL consists in the fact
that the elevator and the conveyor are one
piece of equipment.
Michael Rivkin ■
Re: Conveying Of Salt
salt conveying
Dr Rivkin is right about mechanical conveying advantages.
However I prefere the cheaper classic mechanical conveying
suggested by mr Lommegts.
Anyhow before final decision please consider the layout & free
available space.
sincerly
S.Bar
S. Bar
Chief Engineer
Ludan engineering LTD. ■
Conveying Of Salt
You can conveying salt pneumatically in dilute phase
For any info or offer you can contact me at
Govoni Simbianca Impianti
+39 051 6847286 ■
Re: Conveying Of Salt
As I have seen, common salt is hygroscopic in nature. If the climate is likely to be very humid during certain period of the year, please see what will be the implication on the performance of the conveying equipment being used, whether this is mechanical conveying or pneumatic conveying.
Won't the mechanical conveying be less susceptible to this situation?
Regards,
Ishwar G Mulani.
Author of Book : Engineering Science and Application Design for Belt Conveyor
Advisor / Consultant for Bulk Material Handling System & Issues.
Email : parimul@pn2.vsnl.net.in ■
Conveying Of Salt
You are right, but... if the compressed air will be
dried properly, pneumatic system is the best way
to convey hydroscopic material.
Many years we successfully convey very hydroscopic dry
carnellite (25-45 tph) using dense phase pneumatic
systems.
The route of conveying is so intricate that only
pipeline could be used.
Depending on the equivalent length of pipelines,
the solid/air ratio is 23 to 40.
We get 5-7% undersize as result of the conveying,
but you always have to pay some way.
Michael Rivkin. ■
Re: Conveying Of Salt
Dr. Rivkin is right, if proper care is taken in design, the pneumatic conveying system can suit the application, as per their experience and technology.
Regards,
Ishwar G Mulani.
Author of Book : Engineering Science and Application Design for Belt Conveyor
Email : parimul@pn2.vsnl.net.in ■
Re: Conveying Of Salt
Acually salt is a very generic name for sodium chloride and the other components that are in it( even minute quantities of Magnesium Chloride or Calcium chloride) will cause moisture absorption.
The main problem with salt is not the moisture pick-up, but caking phenomenon, which is normal for similar crystals, such as Ammonium sulphate, Ammonium chloride( it is a phenomenon of solubility and temperature).
Pneumatic conveying should not be problem, provided, you avoid any dead zones.
Think about it!( you can convey 10,000 kg/hr salt with air 1000 kg/hr and if the water in air (say 0.01 kg/kg dry air=10 kg will it make any difference?) or increase the equilibrium moisure of salt! ■
Thank You
Thank you everybody for your answers !!
I will consider what to do..
Pål G ■
Re: Conveying Of Salt
Originally posted by Dr M.Rivkin
In the similar case for a food salt we successfully
used the FLEXOWELL pocket elevator ( white rubber)
having vertical & horizontal sections.
This is a very simple and reliable option for you.
Michael Rivkin
TRANSCO de Colmant Cuvelier in France could supply white rubber.
www.transco.tm.fr ■
Re: Conveying Of Salt
Choice between mechanical and pneumatic systems depends primarily on the conveying route and distance. For short and straight systems mechanical conveyors should be suitable but for long and complex routes, pneumatic systems are better. I would prefer dilute phase conveying because of its simplicity. Because salt is hygroscopic, I would use a closed loop system with dry air.
Regards.
Tim Agarwal
Pneumatic Conveying Consultants
www.powderandbulk.com/pcc
polypcc@aol.com ■
Re: Conveying Of Salt
Dear Pål,
I would like to point out at this stage that one needs to look into the total life cycle cost including the cost of maintenance! Cost of maintenance could be extremely high in scandinavian countries and hence there is need for use of Pneumatic conveying systems for bulk transport !
Since you have already a brief knowledge of our facilities and expertise in this field I need not talk about that !
However, if you need any assistance with regard to design of such system I would be glad to be of assistance ! The distance is quite short and hence the design would be rather straight forward !
with best regards
Biplab k Datta
biplab.k.datta@hit.no ■
Re: Conveying Of Salt
What about use of Vertical Screw Conveyor in the use of Salt Conveying if prefering Mech. conveying?
Hasan ■
Salts Conveying
Dear Mr. Gjerd
The salt conveying is similar to the cement Raw mix transport to the silo . The salt is a humid / wet material in nature ,and can be coagulated and makes bridging . Alaso the salt is very abrasive material . To transport the sult by a pneumatic conveying system it will be very expensive from investment side or from maintenance side due to the corrosion of the mechanical parts if it is for the piping ( mainly the elbows ) and don't forget the friction effect of thesalt granulate particles, or the compressor parts ) , Also don't forget the salt heating cost . For the pneumatic transport installation in addition to the piping and compressor you need to install a dust collector / aleviator to de-aerate the conveying air dilivered by the compressor .
It is more suitable to install a rubber bucket elevator , because with that the investment cost is more cheaper , the maintenace cost is nearly negligeable and the operation cost is very less comparing to the pneumatic system ( Power consuption ) .
If you feel in need for further information , please don't hesitate to ask for .
Best Regards
DR ENGR . Shafic Ragheb Shreyteh Ph.D
Engineering Consultancy Bureau for Cement Industry
End of Freres School Street
Shreyteh Building
Rmeileh –Lebanon
Tel : ++ 961 7 990688
E – Mail : Saradouniana@hotmail.com ■
Conveying Of Salt
I have detailed the largest salt manufacturer TATA's salt handling sysytem using pneumatic and mechanical handling equipments. for more details get in touch directly. ■
Post 1 - Conveying Salt
Dear Mr. Prafulkhanderia
I am sorry for the detail because I was outside of the country.I don't understand your reply on my previous reply to the forum concernig the salt conveying . You wrote that " you have detailed the largest salt manufacturer TATA's salt handling system using pneumatic and mechanical handling equipments , for more details get in touch directly " .Please to clarify what you mean with this reply .
We have an Engineering Consultancy Bureau for Cement Industry with more than 25 Years experience in this field mainly with material handlin and tansport ( pneumatic and mechanical ) . This is for your information and use . If you feel in need for more information please to not hesitate to contact directly .
Best Regards .
DR ENGR . Shafic Ragheb Shreyteh Ph.D
Engineering Consultancy Bureau for Cement Industry
End of Freres School Street
Shreyteh Building
Rmeileh –Lebanon
Tel : ++ 961 7 990688
E – Mail : Saradouniana@hotmail.com ■
Vertical Screw For Salt
A vertical screw has been successfully applied at a US plant to move 100 tph with 45 foot lift using 60 hp drive, in a 16 inch diameter screw. This was put in as upgrading to get rid of bucket elevators, and the belt-particle product contamination that can come from that.
Supplier is KWS Manufacturing of Burleson, Texas, USA (use Bulk-Online search to find contact specifics). See www.KWSMFG.com .
Be warned: getting it to be trouble-free is not as straighforward as it might appear! It took two tries to get it right for the small-particle diameter salt (screw-to-wall clearance is critical).
David A. Crea, P.E.
Consulting Process & Energy Engineer
Creative Process Engineering ■
Salt Conveying
I am curious as you do not mention whether it is rock salt or evaporated salt. my feeling is that you would be better off using
a capsule pipeline for this system, as they use very little energy.
the pipeline does not wear as the small capsule trains ride on rubber tires as low pressure high volume are blows them from point to point, or in your case the the return trip could use gravity.
the bad thing about conveyors of any type is that we tend to forget about them and then things only get worse.
the units provided by www. pnuetrans.net are very cost efficient and have low maintenance. I do not like conveyors or elevators as they can be the weak link in the chain and will break-especially with salt and its corrosive properties. With elevators you have to worry about the chains breaking or the rivets popping or the key holding the sprocket of the elevator falling out.
No I do not sell them. ■
Salt Conveyor Belt
Dear sir;
We are french manufacturer of white rubber abrasion resistant,
food grade, anti static, fire retardent and ATEX II 1D zone 20.
www.transco.tm.fr
We could supply to you conveyor belts for sugar
Many thanks
Best regards
i.caroen@colmant-cuvelier.com ■
Re: Conveying Of Salt
Dear Pal,
Your best option is to use a dilute phase pneumatic conveying system with dry air. You do not need dense phase conveying for salt. Use a pressure type conveying system to prevent sucking-in humid atmospheric air into the conveying system from a loose pipe line joint or from some other connection. Dry air is not necessary if you can chill the conveying air sufficiently so that it does not reach its dew point within the conveying system. But you will need a dry air blanket in the bins or silos that will be used to store salt.
Amrit T. Agarwal
Solids Handling Consultant
Pneumatic Conveying Consultants
polypcc@aol.com
www.powderandbulk.com/pcc ■
Watch Out For Dust Generation!
I am familiar with two side-by-side parallel-operation dilute-phase salt transport systems for about 50 feet vertical and 250+ feet laterally through 3-1/2 inch tubes as I recall, taking 2x40 hp motors for the blowers running at about 7-9 psi, and transporting typically 12 tph of NaCl salt from a Swenson Evaporator/Top Feed Filter System. I measured about 15 tons/day of dust coming from that system, MOST of which I believe was formed in the pneumatic transport systems themselves, which reached velocities of ~6,000 feet/min at the end as I recall. PLUS, the rotary valves into a system like this are a mechanical-relaibility nightmare, because the operators wash-out at least 1x/day, plus whenever plugged (sometimes 6x/8-hour shift), and shoot water into the bearings. You MUST purge them with auto-lubers, at about 250cc/month, for survival. ■
Conveying of salt
Dear Sirs !
Do anybody have any experience in conveying of salt, bulk weight 1,2. I am supposed to transport on top on a silo, 40 meter vertical, followed by 50 meter horizontal.
May i use dilute/dense phase – or should I use elevator? Do salt petrify in bend and receiving silo?
With best regards Pål G ■