A packing line, a seeding machine or a van are the devices you may need for your business. Every entrepreneur knows that cost is not only the purchase price, but there are also operating costs. This is certainly no different with a food freeze dryer. Let's try to summarize what it costs to operate such a machine.
AMARU needs 3 things to live, ranked in order of need:
Electricity
Electricity is the basic medium for the operation of the lyophilizer.
The first thing we need to do is freeze the product. Let's count on a typical load of 7.5 kg of vegetables cut into small pieces. Freezing such a load normally takes 15 hours, which means a consumption of about 6 kWh. If you freeze the food in a countertop freezer, you will definitely save energy.
When freezing food alone, the AMARU consumes about 9.5 kWh/day, while the freezer we offer consumes only 0.55 kWh/day. In addition, the box can freeze multiple batches at once.
However, it is good to keep in mind that even using a storage freezer does not completely avoid the freezing phase in the freeze dryer. However, this is shortened to about 5-7 hours to achieve the required minimum temperature of -25°C.
The next stage is the drying itself. Here AMARU consumes approx. 27 kWh/day. A number of test sets where we measured the consumption came out consistently at a total consumption value of around 33.5 kWh. Of course, it is also worth reading our previous article:
I am still deliberately avoiding mentioning the price, as this will vary over time due to the price per kWh. Someone may also have their own overcapacity from a solar power plant and be more interested in consumption than price. However, if we start from the current electricity price of 1 kWh = EUR 0,25 (source: energie123.cz, July 2023), then one batch (without freezing) can be about EUR 8,40.
Oil
Every freeze dryer includes a vacuum pump, which cannot do without oil (unless it is a dry pump).
The vacuum pump supplied with AMARU needs 500 ml of oil, which lasts about 300 hours of drying (the vacuum pump does not run during freezing). It may be a little more or a little less. It is rather important to check the oil condition and change it at the first sign of cloudiness, otherwise the performance of the pump will be reduced and so will its life.
Cloudy oil worthy of replacement
Vacuum pumps need a mineral oil designed for them. We have our own proven type that we use both in AMARU and for biotech freeze dryers in laboratories and production plants. One batch (500 ml) costs approx. EUR 7,--, so the cost for 1 process is EUR 0,70.
Service
AMARU is an instrument like any other, so I will not tell you that it does not need service. If the lyophilizer is going to be part of your production, it would certainly deserve to be ordered at least one preventive maintenance every 12 months of operation.
Summary
So, if we leave the freezing to AMARU alone and decide not to use a storage freezer, the cost calculation for a typical process with 7.5 kg of product at around 85% moisture content would be roughly as follows:
Freezing phase 15 hours: 6 kWh = EUR 1,50
Drying phase 30 hours: 33,5 kWh = EUR 8,40
Oil for one batch = EUR 0,70
Total price EUR 10,60
If we processed an identical loading with the help of the freezer we offer, the calculation would be as follows:
Freezing the product 24 hours: 0,55 kWh = EUR 0,13
Temp. stabilization on AMARU 5 hours: 2,8 kWh = EUR 0,70
Drying phase 30 hours: 33,5 kWh = EUR 8,40
Oil for one batch = EUR 0,70
Total price EUR 9,93
However, it is worth noting here that the calculation does not take into account the fact that the storage freezer will freeze three loads (15 product trays) and the savings would be even higher. Another indisputable advantage is that the freezers create a "buffer" of loads (e.g. during the season) which AMARU can then gradually dry, but this is discussed in more detail in the article Freezing before freeze-drying in a freezer.