Hot ash conveyor

Posted in: , on 16. Jul. 2007 - 15:34

I have a reactor in which hot ash (grain size < 2 mm size, flow 20 kg/h or 0.25 m3/hr ) is to be removed continuously without any air leakage into the system.The system is operating under a suction of 100 mmWC.

As of now we have a tank in which the ash collects and the same is emptied periodically resulting in downtime.

Please help.

Re: Hot Ash Conveyor

Posted on 16. Jul. 2007 - 02:22

Originally posted by shivanandr

hot ash (grain size < 2 mm size, flow 20 kg/h or 0.25 m3/hr )

Hot, how hot?? A temperature would help.

Matt Mayo
(not verified)

Re: Hot Ash Conveyor

Posted on 18. Jul. 2007 - 10:43

Our SLIPSTICK conveyor has been used with dual staged discharge doors in this manner for ~1000 F temperatures.

It is a horizontal motion vibrating conveyor that accommodates thermal expansion well.

Let me know if this is of interest.

Matt Mayo

Triple/S Dynamics

Hot Ash Cooler

Posted on 20. Jul. 2007 - 07:25

Hot ash maybe removed from your tank from underneath using a flange connection to prevent leakage. By allowing hot ash to drop over a HOLO-FLO, the ash may be cooled to your required temperature or your equipment may be protected from the detrimental effects of heat. A HOLO-FLO is essentially used in cooling hot bottom ash from fluidized bed boilers. These are water cooled hollow screws used in many different applications. The cooling or heating medium maybe circulated through the flights and stem pipe for an indirect heat exchange between the product and heat transfer agent. Your housing may also be made tubular to handle the negative pressure. However, hot ash is considered abrasive and corrosive. The flighting directly underneath the tank should be equipped with special flighting design. Please send me your application with complete info so I can provide you with sizing estimates at Thank you.

Re: Hot Ash Conveyor

Posted on 21. Jul. 2007 - 04:19

Further to Designer's reply; can you please also define "tank" a little deeper.

It has been generally thrashed out that tanks contain liquids & bins contain solids. Hoppers are the tapered bits at the bottom of bins, except in Western Australia where hoppers are pump sumps.

With 20kg per hour to shift ,your downtime troubles are hard to understand.

Is it possible to make a hollow flight screw conveyor to handle 20kg per hour? I mean.

Bottom ash usually contains some large lumps, sometimes as big as a MiniMinor, which is not the scene hereabouts.

John Gateley

Hot Ash

Posted on 23. Jul. 2007 - 08:56

HOLO-FLO is designed to handle bottom ash up to 1” in lump size for small units such as the application requested by shivanandr. He is only running 20 kg/hr. While assuming the inlet temperature, he might just need a 7” diameter unit. HOLO-FLO may be designed to handle as much as 4000 lb/hr of bottom ash and can handle lump sizes of up to 3” in size.

Lyle Brown
(not verified)

Re: Hot Ash Conveyor

Posted on 23. Jul. 2007 - 10:42

Some of the earlier QEGB power stations used a periodic dump hopper (most use SCC's now), which may be suitable considering your required capacity.

I underderstand Rolls Royce Engineering Australia which was then John Thompson which was then BRW which is now Worley Parsons may have experience in this field:

This company has some products which may be of interest:



Hot Ash Conveyor

Posted on 24. Jul. 2007 - 08:21

Dear Lyle,

HOLO-FLO units were derived from its original inventor, Mr. Joseph Christian of Christian Engineering. They were originally located in San Francisco, CA and started selling this equipment in early 1950,s. His invention was quickly accepted by the power industry because it provided complete and working solution for handling bottom and fly ash. Through the years, CE had developed business relations with other suppliers and agreed to license the product. We provided technical support and manufacturing procedures to all of our licensees. The product market grew tremendously including Asia and Europe.

In time, new products emerge in competition with this design. However, the use of Bottom Ash Screw Coolers including new developments in their design still proves that it is still the best out there.

If you have any application in mind, I would love to discuss further. Please send any questions or query to