Kamengo Technology has developed the "Moving Hole" feeder which has been successfully used for biomass applications since 1990, ranging from fuel feeding at the boiler, to intermediate storage, to feeding from an outside storage pile. The feeder enables "effective" discharge from a storage hopper while avoiding compaction of the material. Woodchips and hog fuel have low bulk density, are highly compactible and can bridge over large dimensions. While we have used a diverging bin design for the smaller storage systems, we have successfully used a converging mass flow design with the "Moving Hole" feeder when significant storage is required.

The "Moving Hole" feeder was specifically developed for biomass fuels, subsequently the technology has been used for a wide range of materials and applications including self unloading ships for bulk cargoes such as gypsum and coal. Our company won an award on innovation in cargo handling in 2002 based on performance of the "Moving Hole" feeders on a new ship, the M/V Gypsum Centennial:

http://www.kamengo.com/publications/...the%20show.pdf

We are currently working on a second identical ship currently under construction. The latter project was done in partnership with MacGregor Bulk - see article below:

http://www.kamengo.com/publications/...Operations.pdf

We have a couple of possibilities for your woodchips/hog fuel unloading application. If you decide to stay with the crab crane concept, these could be unloaded into an overhead storage bin on the shore, to load out directly to trucks. We have currently a 500 m storage system in northern British Columbia, Canada, that loads out to truck trailers. Alternately, you can have one or more hoppers on the deck of the ship for the grab crane to unload into. The hoppers can be discharged via "Moving Hole" feeders on to a belt conveyor. The hoppers and feeders will have sufficient capacity to exceed that of the grab bucket volume and frequency.

The "Moving Hole" feeders can also be used to unload the Panamax vessels. Hopper design is even more critical for a self unloading ship as you would like to maximize the storage capacity of the ship and at the same time avoid bridging. An "expanded flow" hopper design consisting of a mass flow hopper above the feeder to exceed the "doming" dimension followed by a rather shallow "funnel flow" hopper will provide the most efficient unloading system. A critical parameter is the diagonal of the outlet which must exceed “piping” dimension to avoid a stable rat-hole. With the long outlet and feeders used on ships (30 m +), the "piping" dimension for most cargoes is exceeded by a good safety margin.

A self unloading ship with "Moving Hole" feeders can be unloaded at a high controlled rate to match capacity of the shore conveyors.

Nazmir Bundalli, P.Eng.

Kamengo Technology Inc.

Ste. 590-4400 Hazelbridge Way

Richmond, BC Canada V6X 3R8

Tel: +1-604-270-9995 ■

Sandwell Engineering Inc. has extensive international experience with the design of hog fuel handling systems, biomass fired boilers and ship loading and unloading systems. See our website at www.sandwell.com

You can contact us as follows.

G.F. Paul Janz, Wood Processing Specialist

SANDWELL ENGINEERING INC.

885 Dunsmuir Street, Suite 600

Vancouver, BC V6C 1N5 Canada

tel604-684-9311

direct tel604-638-4628

fax 604-688-5913

emailpjanze@sandwell.com

webwww.sandwell.com ■

I would have considered a crane(s) unloading into a large mobile hopper which in turn could be arranged to feed either to lorries, or to a conveyor system to storage. There is a system like this at Mersey Docks handling poor flow animal feed to flat stores. The flat store has a novel mobile conveyor that maximises the storage capacity in the flat store building. I imagine it could be adapted for wood chips. ■

Unless someone can correct me I'd have thought it unlikely you can get a pneumatic conveying system to pick up from a vessel at 500 te/hr.

Also, I'd have thought for the volumes involved it would have needed a flat store rather than a silo? ■

Wood pellets are not difficult to handle and can easily be stored in silos provided that they haven’t been in contact with water. It only takes a few drops of water to fluff the pellets if this happens then it is a man with jack hammer in the silo kind of job. There are references of 5000 m3 silos in UK for wood pellets that I am aware of.

Wood Chips are different and there storage will depend on chip size and moisture content. Wet chips and silos don’t go very well.

As far as 500 ton vac. unloading again looking at the grain unloader thread (which I think is designed) I think it is very much possible for wood pellets but will it be feasible on power consumption ??? That is the million dollar question. ■

But back to the first post they were talking about wood chips (or hogged chips) not pellets. Pellets are nice but they don't always stay pellets and well broken pellets are not nice!

As with all things, the type of storage and discharge depends on clients requirements and the required storage volume. Wood chips can be stored in silos, but I would expect that for a power project large quantities will need storing and silos may not be appropriate, flat stores being more suited with automated reclaim. ■

So you could use more than one grab then.

Setting aside the question of power consumption, there is the question of the flowability of the wood chips. Sucking up bulk material like grain that flows readily to a suction pipe is one thing, sucking up poor flow materials that stand up cliff like and look at you is something else. Just search for patents covering all manner of gizmo's that have been put on the end of suction pipes to bring material to the inlet because stuff doesn't flow.

See how they unload coal and ore at bespoke quayside's at high capacity. It's all big expensive kit normally involving large diameter bucket wheels at the bottom of bucket elevator legs. ■

Have you been yet? ■

I'm not surprised at high costs and long delivery times as these will be bespoke machines not something made in quantity and available off the shelf.

Can you say the manufacturer?

Neuero perhaps? They have a machine listed at 600 m3/hr at Essent in the Netherlands.

There seems to be a lot of interest in unloading wood chips/pellets in the north east of the UK currently. ■

Ship unloading is a black art. Some hidesously complex machines have been tried and found wanting because of design fantasy, power consumption and reliability. The only reliable way to get in-bulk crud out of a confined space is by grab. Means to eliminate dust and improve grab unloading performance have been sadly neglected; probably because the cranes and grabs are usually made separately.

Has there been a study on the pollen levels around a woodship unloading operation? It's a bit overdue in 2008, already! So much for HSE.

Digging, elevating and gathering bulk cargo are separate activities of the unloading operation and there needs to be more study concerning where, when and how the transitions between the activities occur. Consider the major culprit of grab unloading, slewing to a shoreside hopper. This period reduces the machine capacity dramatically. A grab and lift operation has been completed and then followed by a dubious horizontal (level luffing?) transfer operation which could well be performed by a conveyor, once gathered.

It's more satisfying talking to a wall. ■

The thing about ship unloading is if you buy a bespoke bulk material unloader it's just that. Change material, it might not work as well. And if you want to sell it second hand there's only a limited number of buyers.

Now if you have a crane and by a grab it's more flexible and if you want to sell it, well a crane's a crane isn't it. ■

Some don't even need a change of material before they don't work so well. Dare I mention the Simporter and Siwertell machines in the same breath as that Kone effort with a little bucket wheel on the end of an oil rig mast. They all raise a gasp.

A crane is multi purpose, so is a grab, and as designer says they have some resale value. ■

Originally Posted by Matt Jones

We have a design of hopper which will be ideal for your woddchip unloading operations.

These bulk intake hoppers are qute common these days and available from a number of suppliers. ■

Originally Posted by MGTPOWER

MGT Power is developing a wood chip / hog fuel unloading facility as part of a large power project. The quay will need to unload 5 million cubic meters per annum of wood chip, or approximately 30,000 m3 per 24 hour working day. This fuel will be delivered in panamax vessels, ie approx 1 vessel per week.

We are trying to identify companies which have experience with the design of such facilities or the supply of equipment for these type of facilities.

Our outline concept is to use 2/3 grabbing cranes which discharge either to concrete pad, road vehicle, or lastly to a conveyor, via a hopper. We are very cautious about the use of hoppers due to the risk of bridging with a poorly designed hopper.

The fuel will have a broad range of particle size, and moisture content from 20% to 60%.

No problem we have pneumatic chip loading system in operation since 1973 with capacity of 1,400 Tons Per Hour and have taken it as high as 1,800 TPH email walls@comcast.net ■

[QUOTE=muhandis89;45461]I am examining this problem in detail for a generation facility in Europe.Feedstock levels call for 2 mill tonnes plus,in a 12 month period,to be sustained for 25 years.With demurrage rates high on Panamax(40k tonnes)vessels ,it is in everyone's interst to have these ships unloaded quickly,into weather proof silos.Setting aside silo sizing,which is related more to consumption of wood chips at the generator end,one needs to look at the infrastructure and equipment required to offload 40000 tonnes of material a week(or about 240 tonnes/hr on a continuous basis),that still means that a vessel could be detained,for more than 3 days,at the offloading port.One also needs to prevent the cargo being affected by rain etc.This means having,where possible,a fully enclosed unloading system,we feel.

At present I am finding that even the biggest grabs,are unlikely to have a capacity to offload more than 1500-3000 tonnes /day,and thus only some kind of air conveyed system is likely to work.Additionally such a method could also propel the cargo,after unloading into a silo,and even be used to 'warm' ,or condition the material. ------------------- REPLY:

No sweat we have 'The Monster' pneumatic system operating since 1973 loading wood chips @ 1,400 Tons Per Hour capacity, once ran it for 24 hours at 1,800 TPH blows away the competition! Also couple of 'mini monsters' performing at 800 Tons Per Hour for >20 yrs. Calculation basis Douglas Fir @ 530kg per cubic meter

500 tonnes per hour - piece of cake.

Need an offer?

email and we'll supply price and delivery. Location west coast USA

thx pete ■

Originally Posted by muhandis89

I am examining this problem in detail for a generation facility in Europe.Feedstock levels call for 2 mill tonnes plus,in a 12 month period,to be sustained for 25 years.With demurrage rates high on Panamax(40k tonnes)vessels ,it is in everyone's interst to have these ships unloaded quickly,into weather proof silos.Setting aside silo sizing,which is related more to consumption of wood chips at the generator end,one needs to look at the infrastructure and equipment required to offload 40000 tonnes of material a week(or about 240 tonnes/hr on a continuous basis),that still means that a vessel could be detained,for more than 3 days,at the offloading port.One also needs to prevent the cargo being affected by rain etc.This means having,where possible,a fully enclosed unloading system,we feel.

At present I am finding that even the biggest grabs,are unlikely to have a capacity to offload more than 1500-3000 tonnes /day,and thus only some kind of air conveyed system is likely to work.Additionally such a method could also propel the cargo,after unloading into a silo,and even be used to 'warm' ,or condition the material.

Our aim is to offload,at least,500 tonnes/hour,more if possible.

Mohd. key is the bulk load density, increase the impact velocity and density will improve, also the higher velocity means you can load and or unload at higher speeds using penumatic systems, as mentioned we have 'The Monster' operating on west coast USA since 1973 and at 1,400TPH we can offload your 40,000 ton vessel in just 28 hours, ok call it tonnes and make it 30 hours, then again if you wanted to offload in 24 hours we could offer 1,800 TPH solution that would 22hrs for 40,000 tons or say 24 hours for 40,000 tonnes.

You dont need 3 days or even 2 - we have the one day 24 hour solution. pete ■

Dear Sir, can you let me know the dimension of wood chip?

I f you have more detail, pls. send to me via e-mail: setavietnam@gmail.com

Regards,

Pham ■

As you are deailing with high moisture material:

a sewer cleaning truck will have the power in Hg

and volume per hour to do this for you with no issues.

A standard rail width (USA) size mounted supersucker brand

vacuum truck with the pneumatic unloading option is

really the only answer beacuse of your materials and

your moistuire content that will be able to handle

what you are off loading as the material will be wet.

The trucks can be placed away from the quay to reduce

congestion with no loss in vacuum Hg.

The trucks have an auger delivery system that removes the

material as it enters the tank while the tank is raised for

material discharge.

www.superproducts.com

lzaharis ■

Originally Posted by rousseau franck

wood pellets are not difficult to manage with a good planetary extractor

The main thing is to get enough torque in case of hard product

You can get information with Morillon in france

Do you do SHIP UN-LOADERS then? ■