Re: High Temperature And Abrasion Resistant Eductors
Dear Sir,
we would recommend to use ceramic diffusors made from SiSiC. We still using this in an application for transport of boiler ash since more than 2 year continuos operation. The diameter of conveying line is about 6", max. throughput about 6 t/h.
For more informations pls. visit our website: http://www.enviro-engineering.de
To your questions:
a) full ceramic-diffusor (exchangbl.) would be recomm.
b) Hardness of most metal diffusor decreases with temperature, SiSiC-Hardness remains stable in this temperature range.
c) Other methods especially for sand are J- or L-valves (Non mechanical valves)
d) Most economical size would be about 6" (For roots-blower)
If you have high-pressure air (6 bar = 90 psi) 4" can be sufficient.
If you have further questions don´t hesitate to contact me.
Regards
Klaus Schneider ■
High Temperature Eductors.
Hi Dave,
For high temperature sand conveying I would recommend Reaction Bonded Silicon Carbide lined eductors.
Metals do loose their hardness with temperature, as mention by Mr. Schneider in the previous posting.
Based on a maximum material density of not more than 3, and a maximum conveying distance of not more than 50 metres, a 100mm bore eductor will move between 3 and 5 tonnes per hour; a 75mm eductor will move 2 and 4 tonnes per hour and a 125mm eductor 4 and 6 tonnes per hour.
A <10 micron fine grained engineering grade Reaction Bonded Silicon Carbide will be the most effective ceramic to use with hard sharp sand. Refractory grade SiCs can be used also (their grain sizes tend <150 microns), but small sharp particles of sand (often with harnesses of around 1100 Vickers) will pick away at the larger silicon grain boundaries, resulting in faster erosion of the ceramic; however, a refractory grade SiC will be the less expensive option, but an engineering grade RBSiC will prove more cost effective when handling sand at high velocities.
I have attached a photo of RESILIDE (TM) RBSiC lined high efficiency, inline, eductors suitable for the high temperature application you have described; also, I have attached a graph detailing comparative wear resistance of commonly used wear resistant materials.
95% alumina ceramic will handle 500 to 600 degrees easily, but its thermal shock resistance isn't good and you would need to be sure of a relatively slow warm-up.
CEROXALIDE Z4 (TM) is an almost pure metal oxide ceramic capable of operating in temperatures up to 1800 OC.. This ceramic has a microstructure with an extremely fine grain boundaries, offering around 3 times the wear and thermal shock resistance a 95% alumina ceramic, and excellent resistance to high velocity silica sands.
The hardness of 95% alumina is 1100 Vickers; a similar hardness to some silica sands. CEROXALIDE (TM) has a hardness close to close to 2000 Vickers and the hardness of RESILIDE (TM) is around 3000 Vickers. I guess the hardness of your sand will be in the region of 1000 Vickers.
Please let me know if you require further information
You may wish to have a look at the following web sites:
www.pacificjunction.com
www.omegaslate.com
Regards,
Mike.
Attachments
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Wear Resistance Comparison Graph
Re: High Temperature And Abrasion Resistant Eductors
We provide wear resistance solution of many wearing components without failure against severe abrasive attack and abnormal loading condition by fixing laminated wear plate to ASTM specification A 532 type 2 with Chromium 14 to 18%and Molybdenum 2.5 to 3.5 %, metallurgical bonded having hardness 700 Brinell to a mild steel backing plate. The bond joint is strong metallurgical bond with > 33,000 psi . Further details can be discussed on receipt of your confirmation by E-mail. ■
Re: High Temperature And Abrasion Resistant Eductors
WE HAVE DEVELOPED AN ALLOY TO COMPETE WITH CROME CARBIDE IN HIGH TEMPERATURE APPLICATIONS OF PNEUMATIC CONVEYING.
THIS HAS ALRREADY BEEN TESTED AT 650 DEGREES C. cOST WISE IT WOULD BE LESS THAN 50% THE SiC WITH ABOUT THE SAME LIFE
iF YOU ARE STILL INTERESTED
sEND ME AN email.
Marco ■
Thigh Temperature And Abrasion Resistant Eductors
We would recommend the following eductor for this application:-
6" Eductor ref. 320-WRE-CER-SiNi-SS-FLG
Body and nozzle: machined from 304 s/steel
Venturi Liner: Silicon Nitride
Motive Air Connection: 125mm NB Flange
Suctionand Discharge Connections: 150mm NB Flanges
This will provide the most economical size of eductor for this application and the conveying line should not be less than 6" internal diameter.
The liner will be Silicon Nitride with silicon carbide bonding.
Availabilty: Approx 10-12 weeks from receipt of order.
For further information please contact:
sales@procol.dowsongroup.com ■
High Temperature and Abrasion Resistant Eductors
I have a client who wants to move hot sand (500 to 600 degrees centigrade) in ten tonne batches, twice a day. Conveying speed is not very important and a two hour cycle can be accomodated.
The sand is to be lifted through a height of 15 feet over a horizontal distance of 25 to 50 feet.
We are debating the feasibility of using an eductor based pneumatic conveying system.
There are a few points that concern us:
a. do we use a hard metal or ceramic lined eductor?
b. how is the wear resistance of hard metal/ceramic effected by
temperatures of 5/600 degrees centigrade?
c. is there another method of conveying the sand, which may
prove more effective?
d. what is the most economical size of eductor for this duty?
Any answers, or comments relating to the above questions would be welcomed. ■