Water enters an ice machine at 55F and leaves as ice at 25F. If the COP of the ice machine is 3.7 during this operation, determine the required power input in horsepower for an ice production rate of 15.0 lbm/hr. Know that 169 Btu of energy needs to be removed from each lbm of water at 55F to turn it into ice at 25F.

The required power is

Explanation:

From the question we are told that

   The temperature of the water entering ice machine is

    The temperature of the water leaving is

    The COP of the ice machine is

    The production rate of an ice  

    The energy that needs to removed from each lbm of water at 55 F is

Generally the cooling load of the ice machine is mathematically represented as

=>  

Generally the COP of the ice machine is mathematically represented as

Here is the net power  input needed to successfully run the ice machine

So  

=>  

Converting to horsepower

=>  

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia