Energy saving in industrial air cleaning and filtration systems... it's about more than just being "green"
We like this statement. It summarises the concept of energy saving and is particularly well-suited to the case of aspiration systems.
We want to go beyond policies imposed by company boards who boastfully position their "green" logos on their home page or letterheads.
An aspiration plant is an auxiliary, as opposed to a process plant, it does not generate goods, therefore it does not generate turnover, I'd be grateful if I could do without one! What's more, it is demanding in terms of energy consumption.
Here follow a few examples of plant sizing:
As you can see, aspiration plants are extremely demanding in terms of absorbed power and indicatively could be ranked in terms of energy consumption as follows:
1st place: centrifugal aspirator
2nd place: blower for pneumatic conveyance (if present)
3rd place: bag filter cleaning systems
4th place: silos extraction systems
5th place: rotary valves/ compartmentalisation valves
6th place: conveyance augers
Blowers for pneumatic conveyors are supplied by a handful of the sector's top companies who have extensive awareness of this issue. However, centrifugal ventilators, notoriously low efficiency machines, are present in an infinite array of solutions which means that particular care is required when selecting the right technical solution.
The technical solution makes all the difference!
Compared to direct coupling solutions, belt conveyors consume 6-12% more electricity, and this grows according to installed power.
If you believe that an aspirator with direct coupling costs more than solutions with belt conveyance then you are mistaken:
The cost of transmission is comparable to the cost of the coupling joint, with the advantage that the coupling joint does not need maintenance or tightening!
Inverters by top brands on the market (e.g. ABB, SIEMENS; TOSHIBA) enable you to manage frequency reductions up to 25Hz (therefore theoretical consumption reductions of 50% based on a 50Hz frequency).
What about torque? The following graph shows that in the case of frequencies above 25Hz, torque is guaranteed 92% above maximum value!
Belt conveyance was used to enable the selection of suitable impeller rpm based on plant requirements. today rpm is managed by the aspirator command inverter.
Be wary of anyone who proposes the traditional solution alone: they are not a good consultant. Installers need to provide you with solutions, not the just the plant. Remember no one else but you will pay the energy bills.
Directly couple centrifugal aspirators for medium powers.
Case reinforcement may mean heavy applications, or ATEX applications where the machine0's resistance to explosions is important.
Directly coupled centrifugal aspirators for high powers.
Please not the compact size of coupling joint.
Caution: application with inverter will save energy by eliminating loss caused by belt conveyance by ramp start ups and in many cases will also mean that you can eliminate starting valves (valve, electric and pneumatic cables, maintenance).
However, the true advantage of application with inverter is air flow modulation in the aspiration system, according to actual plant requirements.
Example of operation at 44.1Hz with an instant energy saving of 12%
If you have a centralised plant with variable contemporaneity, the system with inverter enables automatic air flow regulation using a pressure witch fitted to the main duct, according to actual equipment in operation, while also guaranteeing minimum air speed for the conveyance of material.
Please do not hesitate to contact O.M.A.R. srl for any further information, we will be happy to help you.
Document drafted by the R&D department - all rights reserved - copyright 2017