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Articles for the Month of July 2015

Green Energy Turbine use examples

Posted on 27 Jul, 2015

Deprag’s Green Energy Turbine generator can be used in either a direct or an indirect configuration.

Direct Configuration:

Direct use of gas turbine generator for green energy

Direct use of gas turbine generator for green energy

In a direct configuration a high pressure gas is run through the turbine. Electricity, lower pressure and lower temperature gas is the result.

 

Some examples include:

  • Energy recovery in metal smelters
    Turn wasted hot compressed air into electricty

    Turn wasted hot compressed air into electricty

     

    • often molten metal is cooled by compressed air.  The compressed air flows through cooling tubes and is normally exhausted to the atmosphere.  The hot, compressed air can be run through the GET and the recovered electricity can be either used by the smelter or fed back to the grid

 

  • Pressure regulation in gas mains
    We can recover wasted energy from reducing the pressure in gas pipelines

    We can recover wasted energy from reducing the pressure in gas pipelines

     

    • natural gas is transported long distances at high pressure.  When it reaches regional areas, the gas pressure has to be lowered.  The pressure is lowered again when before it reaches homes at a local station.  A GET can be used to recover the energy wasted in the pressure reduction.
    • Note, the gas will cool though the process so, it is necessary to pre-heat it before entering the turbine.
  • Carbon sequestration / geothermal
    • Carbon dioxide that is captured from power stations can be compressed and injected into underground reservoirs.  Whilst being stored in the underground caverns the Carbon dioxide is heated by geothermal energy.  The heated carbon dioxide can be expanded through a GET and then re-injected into the reservoir.

 

Indirect Configuration:

The Green Energy Turbine can be used indirectly, for example as a part of an ORC process to capture waste heat.

The Green Energy Turbine can be used indirectly, for example as a part of an ORC process to capture waste heat.

In an indirect configuration the GET is used as part of a waste heat recovery system – for example an ORC (organic rankine cycle).  In such a system a refrigerant gas extracts heat from an object or medium which increases the temperature and pressure of the gas.  This pressurised gas is directed through a GET, which turns the turbine and results in lower temperature, lower pressure gas and electricity.

 

Some examples include:

  • Biogas waste heat recovery
    Systems already exist for large Biogas producers, however Deprag's GET helps small producers to recover energy

    Systems already exist for large Biogas producers, however Deprag’s GET helps small producers to recover energy

    • Deprag supplies low power (from 5kW) units to help smaller producers extract electricity from heat that would normally be wasted.

 

  • Recovering heat out of industrial hot water
    • Deprag is supplying the GET to a company who can extract electricity from hot water.  Hot water is produced in various industrial processes, for example large ship engines, geothermal energy, solar energy and the power industry.  The potential for this already proven technology is enormous and game changing in the green energy and energy recovery industries.

Green Energy Turbine Generator

Posted on 23 Jul, 2015

Deprag’s Green Energy Turbine generator can be used in either a direct or an indirect configuration.

Direct Configuration:

Direct use of gas turbine generator for green energy

Direct use of gas turbine generator for green energy

In a direct configuration a high pressure gas is run through the turbine. Electricity, lower pressure and lower temperature gas is the result.

 

 

 

 

 

 

Some examples include:

  • Energy recovery in metal smelters
    Turn wasted hot compressed air into electricty

    Turn wasted hot compressed air into electricty

    • often molten metal is cooled by compressed air.  The compressed air flows through cooling tubes and is normally exhausted to the atmosphere.  The hot, compressed air can be run through the GET and the recovered electricity can be either used by the smelter or fed back to the grid

 

 

 

 

  • Pressure regulation in gas mains
    We can recover wasted energy from reducing the pressure in gas pipelines

    We can recover wasted energy from reducing the pressure in gas pipelines

    • natural gas is transported long distances at high pressure.  When it reaches regional areas, the gas pressure has to be lowered.  The pressure is lowered again when before it reaches homes at a local station.  A GET can be used to recover the energy wasted in the pressure reduction.
    • Note, the gas will cool though the process so, it is necessary to pre-heat it before entering the turbine.

 

 

 

 

  • Carbon sequestration / geothermal
    • Carbon dioxide that is captured from power stations can be compressed and injected into underground reservoirs.  Whilst being stored in the underground caverns the Carbon dioxide is heated by geothermal energy.  The heated carbon dioxide can be expanded through a GET and then re-injected into the reservoir.

 

Indirect Configuration:

The Green Energy Turbine can be used indirectly, for example as a part of an ORC process to capture waste heat.

The Green Energy Turbine can be used indirectly, for example as a part of an ORC process to capture waste heat.

In an indirect configuration the GET is used as part of a waste heat recovery system – for example an ORC (organic rankine cycle).  In such a system a refrigerant gas extracts heat from an object or medium which increases the temperature and pressure of the gas.  This pressurised gas is directed through a GET, which turns the turbine and results in lower temperature, lower pressure gas and electricity.

 

 

 

 

 

Some examples include:

  • Biogas waste heat recovery
    Systems already exist for large Biogas producers, however Deprag's GET helps small producers to recover energy

    Systems already exist for large Biogas producers, however Deprag’s GET helps small producers to recover energy

    • Deprag supplies low power (from 5kW) units to help smaller producers extract electricity from heat that would normally be wasted.

 

 

 

 

 

 

  • Recovering heat out of industrial hot water
    • Deprag is supplying the GET to a company who can extract electricity from hot water.  Hot water is produced in various industrial processes, for example large ship engines, geothermal energy, solar energy and the power industry.  The potential for this already proven technology is enormous and game changing in the green energy and energy recovery industries.

What is Friction Tightening?

Posted on 14 Jul, 2015

Torque controlled screw tightening has always been the most reliable and easily applied method to produce a quality screw joint.  But is torque control really going to give the perfect assembly every time?

Torque curve based on a friction controlled screw joint

Torque curve based on a friction controlled screw joint

Firstly, what is a perfect screw joint? What do we want to achieve by assembling a screw in a product?

We normally need to join two parts together, but more than that we want to induce tension in the joint so that the parts do not come apart.  Sometimes we also need to seal the parts together to prevent leakage or keep dust and water out.

So the aim for a screw joint is not simply to assemble the screw to a target torque within a set tolerance, but it is to induce a constant clamping or pre-load force.

When we apply torque to a screw joint we can calculate the amount of tension induced in the joint assuming that there is no friction in the joint.  In a low friction assembly (eg machine thread screw into a pre-tapped hole) almost all of the torque will induce tension in the joint.  If you know the pitch of the thread and the torque applied you can then calculate the tension.

Fluctuating screw-in torque influences pre-load force!

What about thread forming and self tapping screws?  We know that a portion of the torque is lost to friction and by doing some analysis we can subtract the friction and figure out the average torque used to clamp the parts.  In most cases this will be enough, but what if the friction is not the same in every assembly?

What if a screw with a thread diameter at the high end of it’s tolerance meets a part with a hole dia that is at the low end of the tolerance?  In this case less torque will be used to clamp the joint and it may not be enough.  At the other end of the spectrum, there could be too much torque which could strip the joint or damage the part.

The solution is Friction Tightening.  The advent of EC and EC servo screwdrivers has paved the way to improving the quality of screw joints.  Today we can assemble the screw, calculate the friction torque and then add the pre-determined tightening torque.  So if the friction torque varies, the actual clamping torque and consequently the clamping force will still be constant on every assembly.

Using the friction torque measurement we cannot use the final torque for statistical analysis anymore.  The final tightening torque is the sum of the friction torque and the clamping torque the final torque accuracy will depend on the quality of the joint and the screws.  We now have to look at the clamping torque only for statistical analysis.

EC screwdriver controller AST40 and friction controlled torque curve

EC screwdriver controller AST40 and friction controlled torque curve

The friction torque method is already well established in the international automotive industry as well as the electronic, mobile technology, household goods and medical industries.

Friction tightening modules are optionally available on Deprag’s Hand Held programmable screwdrivers and machine mountable electric screwdrivers.

For more information or if you would like to discuss an application, please don’t hesitate to contact us.