Hello See, greetings and salutations from my corner of the soon to be frozen "eastern wilderness" @ 1140 feet above mean sea level.

Your puzzle can have many parts: But it initially sounds as if the product you are producing is being left in contact with the piping and fusing with it and the eleltric motor is stalling against a build up of frozen material/caked material.

Are you using thermal overload protection for your electric motors?

1. Inferior quality of individual components.

a. stainless stell is used with corrosive atmosperes/chemicals/products.

2. Dielectric corrosion

a. inadequate grounding of process equipment.

3. Moisture with corrosion

4. Corrosion from disimular metal contact/product contact with piping parts/-components such as the rotary valve.

5 Corrosive process atmospere-you have not mentioned what you are manufacturing/processsing/moving from point to point b.

If you have an eleltric motor that burns out every time at start up the motor quality/ rebuild service may be poor.

If you are using an open frame motor it may be failing due to moisture which sounds like the culprit-by purchasing a sealed motor that should not happen any more- be advised also that motor bearings only require greasing one ot two pumps of grease per year or if they are equiped with babbit bearings a few squirts of oil per month in the oil cups.

The electric motor will fail if it is over greased as well from shorting out-grounding-this will happen regardless of the motor type.

The rule of thumb for any equipment used in a high moisture area is to use waterproof/explosion proof components to eliminate corrosion problems.

Possible solutions:

1. The product you are maufacturing and pushing pumping in the piping should be totally purged/washed out or blown out of the piping in use from the system before the system is shut down and this will eliminate any contact with the material in question and reducing the corrosion potential with the process equipment

2. Purchase of stainless steel components such as piping,thermo- couples, rotary valves, gauges etc.

Please tell us what you are doing and with what material. ■

See, I think you are have trouble with the product being left in the process piping during the shutdown periods and it is creating many problems down stream from the beginning to the end of your process piping from heat, corrosion and contact with the carbon.

Are your electric motors sealed or open squirrel cage? If they are open to atmospere they will short out due to the carbon dust.

Also the thought comes to mind regarding the carbon product it self- how dry is it when it is being moved from point A to B if it is damp it will explain everything-the problems from shut down and restart-along with carbon dust in the motors if they are open to atmospere. ■

Just an idea .

Your motor termal protection or overcurrent protection is far toolarge , the motor should not burn even with a blcked rotor , that is why the protection is there.

I also see,s you might be having humidity condensating on the walls of your bins chuttes and pipes .

If the shutdown is programed can you purge your system of any remaining coal. or can you install diverter chuttes to empty the bins into a container when an unforseen shutdown occurs.

By the way does your coal includes lime?

Also remember coal aereates and flows very diffrent than when it sits down and is lefrt to deareate.

heavier lumps and even overloading can occur as not only the flow properties have changed but also the bulck density.

marco ■