Rank: Guest 
|
Posted By artisdeeian
Is a cement silo classed as a presure vessel? bearing in mind that a delivery of cement by a road tanker requires pressure to discharge the load.
regards Ian.
|
|
|
|
|
|
Rank: Guest
|
Posted By Phillip
No - persuure vessels are designed to a specifc code eg BS5500. I bet your cemnt silo has never been pressure tested.
Regards
|
|
|
|
|
|
Rank: Guest
|
Posted By Clarke Kent
You need to check the operating pressure of the blowers on the tankers discharging into the silo as some operate at 2 bar and therefore could cause your silo to become pressurised.
We once had an incident!! where a tanker was discharging into a silo which was fitted with a dust filtration system on the top. During the discharging operation the filtration system took off and landed some 20m below next to the very startled driver of the tanker.
My understanding of the definition of a pressure vessel is: That if the pressure should exceed 0.5 bar under normal operating conditions then it should be classed as a pressure vessel and the Pressure Systems Safety Regs apply.
The road tankers delivering the cement will be subject to pressure testing / annual inspections by competent persons, so why not the silos.
|
|
|
|
|
|
Rank: Guest
|
Posted By Phillip
For example - Think of the food industry (they are many more examples).
Bulk ingredients (eg flour, sugar) are blown from road tankers into (say) aluminium silos every day. These silos and not treated as pressure vessels. Why should your cement silo be?
|
|
|
|
|
|
Rank: Guest
|
Posted By Andrew Campbell
Check the vent on the silo to ensure proper displacement of air during discharge.
If the tank is sufficiently vented then the tank cannot pressurise to a level of 0.5 bar or above
|
|
|
|
|
|
Rank: Guest
|
Posted By Stuart Nagle
The silo, as it has a filtered vent to the atmosphere, will not be classed as a pressure vessel, which is an enclosed system under pressure (e.g. boilers gas cylinders etc).
Whilst pressure of air is used to 'blow' cementicious materials into the silo's, this is usually fairly low pressure, and is not a static pressure within the silo, but only applied during the period of filling, and normally very quickly dissipated via the filtered vent.
The main risks involved in the movement of fine powdered materials is in fact dust explosions, and man entry/intervention at valves etc to clear blockages. In some situations compressed air nozzles have been used to 'vent' into the materials inside silos to help reduce blockages, bit commonly in cement powder, large 'clogs' of the material (particularly where water has penerated the silo) will require often labour intensive removal that is prone to poor working positions and physical injuries...
hope this assists.
Stuart
|
|
|
|
|
|
Rank: Guest
|
Posted By Adrian Watson
It is not a pressure system as defined by the regulations:
"pressure system" means -
(a) a system comprising one or more pressure vessels of rigid construction, any associated pipework and protective devices;
(b) the pipework with its protective devices to which a transportable pressure receptacle is, or is intended to be, connected; or
(c) a pipeline and its protective devices,
which contains or is liable to contain a relevant fluid, but does not include a transportable pressure receptacle or a transportable pressure vessel;
"relevant fluid" means -
(a) steam;
(b) any fluid or mixture of fluids which is at a pressure greater than 0·5 bar above atmospheric pressure, and which fluid or mixture of fluids is -
(i) a gas, or
(ii) a liquid which would have a vapour pressure greater than 0·5 bar above atmospheric pressure when in equilibrium with its vapour at either the actual temperature of the liquid or 17·5 degrees Celsius; or
(c) a gas dissolved under pressure in a solvent contained in a porous substance at ambient temperature and which could be released from the solvent without the application of heat;
But have regards to Stuarts answer as it provides some useful information.
Regards Adrian Watson
|
|
|
|
|
|
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.