Chem Eng. student design help

[starrbri]

Hello, I am a senior design student and as part of my design I need to freeze a large amount of pharmaceutical over the course of a year, Approx. 1.5 million liters at -20°C. This design will never be built, just on paper. I needed a pall park capital cost and utility cost. Are there any references I can find that will have tables with very rough numbers? Actually designing the freezer system is out of the scope of the project, I just need a rough estimate on costs.

Thanks

[taz24]

Hello, I am a senior design student and as part of my design I need to freeze a large amount of pharmaceutical over the course of a year, Approx. 1.5 million liters at -20°C. This design will never be built, just on paper. I needed a pall park capital cost and utility cost. Are there any references I can find that will have tables with very rough numbers? Actually designing the freezer system is out of the scope of the project, I just need a rough estimate on costs.

Thanks


There are a few other things we need to know.

Pharmaceutical = what?? all products have a specific
heat value per Kg (water = 4.19 kJ per Kg).

Will you put the product in the cold store at -20 or
will you be frezzing it from + temps down to - temps?

When you know your product and the temp the calculation
to store it is easy. The callculation to freeze the product is
a little bit more complicated be still easy enough.

Once you know how much work the system needs to do you
can then size the equipment to suit.

taz.

.

[starrbri]

There are a few other things we need to know.

Pharmaceutical = what?? all products have a specific
heat value per Kg (water = 4.19 kJ per Kg).

Will you put the product in the cold store at -20 or
will you be frezzing it from + temps down to - temps?

When you know your product and the temp the calculation
to store it is easy. The callculation to freeze the product is
a little bit more complicated be still easy enough.

Once you know how much work the system needs to do you
can then size the equipment to suit.

taz.

.
Hi Taz,
I am freezing an antibody suspended in water. I assume it will essentially have the specific heat of water. It will be entering not frozen, about 25°C. For these calculations, I think it is safe to say once the product enters at 25°C and will be frozen to -20°C for a year. I can calculate the energy needed. Is there an efficiency typically used for a large scale freezer?

[taz24]

Hi Taz,
I am freezing an antibody suspended in water. I assume it will essentially have the specific heat of water. It will be entering not frozen, about 25°C. For these calculations, I think it is safe to say once the product enters at 25°C and will be frozen to -20°C for a year. I can calculate the energy needed. Is there an efficiency typically used for a large scale freezer?


Hello.

Ok you need to work out a few things.

Specific heat of water = Specific heat capacity, water: 4.187 kJ/kg

Specific heat of ice = Specific heat capacity, ice: 2.108 kJ/kg

You have 1.5 million ltrs or Kg of water that needs cooling from +20 to 0

Then you need to freeze ice from 0 to -20

Then you finaly need to hold the ice at -20 for 360 days.

Now your problem is time.

Do you want to freeze the water in 1 hour, 24 hours or 1000 hours because removing
the heat is done over time, storing the ice is simple and will take a fraction of the size
of equipment that it would take to freeze the water in the first place.

taz

.

[mad fridgie]

Not really a biggy, 50grams a second (must be a busy sperm bank)
room would be at 50% full about 3000m3, load 30odd kw plus room losses say 20kw do not know where the theory place is) Plenty change out of US100,000
system COP about 2 so roughly 25kw powerdraw.
Unless time changes

[starrbri]

Hello.

Ok you need to work out a few things.

Specific heat of water = Specific heat capacity, water: 4.187 kJ/kg

Specific heat of ice = Specific heat capacity, ice: 2.108 kJ/kg

You have 1.5 million ltrs or Kg of water that needs cooling from +20 to 0

Then you need to freeze ice from 0 to -20

Then you finaly need to hold the ice at -20 for 360 days.

Now your problem is time.

Do you want to freeze the water in 1 hour, 24 hours or 1000 hours because removing
the heat is done over time, storing the ice is simple and will take a fraction of the size
of equipment that it would take to freeze the water in the first place.

taz

.

ok I calculated hoe much energy I need to cool this stuff to -20. Cooling in 24 hrs should be sufficient. Also, I am not freezing all 1E6 liters at once. The product will be frozen over the course of the year, I will deposit about 8000L every 1.9 days.

Also, I need to calculate energy losses to environment to calculate the energy to keep the product frozen. I will assume ambient conditions for my location. Lets keep it at 20°C. How much energy loss is typical for a warehouse style freezer room?

Thanks all for the help!

[taz24]

ok I calculated hoe much energy I need to cool this stuff to -20. Cooling in 24 hrs should be sufficient. Also, I am not freezing all 1E6 liters at once. The product will be frozen over the course of the year, I will deposit about 8000L every 1.9 days.

Also, I need to calculate energy losses to environment to calculate the energy to keep the product frozen. I will assume ambient conditions for my location. Lets keep it at 20°C. How much energy loss is typical for a warehouse style freezer room?

Thanks all for the help!

The values for different materials will vary and the wall
thickness will vary also, but if you work to about
20 watts square metre you will get some usable
figures that are workable.

taz.

Ps your doing fine so keep it up. Well done so far.

taz

.