The following information will assist to understand selection of capacity and product and throughput when forming your User Requirement Specification:
- When discussing capacity it is the ‘input’ weight that is important. The product ‘form’ (shape/size) will influence the amount of product that can fit in the tray that fits into the dryer.
- Input weights of products will vary due to the way it is processed. If possible the product should be compacted or concentrated. You will need to decide on what form you are presenting the final product (powder, flakes, or whole).
- The product could be whole, sliced/diced, pureed, or a liquid form. The volume (loading weight) can be calculated by preparing a sample and laying this out over an area of sufficient size to give a realistic average of form. The height should be limited to 18mm. If you weigh the finished sample and factor the result up to an equivalent weight per square metre you now have a loading factor in kg/M² - for that product. You will need to do this for all products and forms of interest - This spread sheet calculator may help you work out the weight per m2: Weight / m2 calculator
- Some products such as sweet or ripe fruits with high brix can remain soft at normal freezing temperatures. Take a small sample of the product and freeze it in a domestic freezer to determine if it freezes easily. Products that remains soft or is sticky should be ‘flagged’ as difficult. Be sure to work with the exact style of product you are proposing to dry.
- You can expect to recover all of the dry material after processing, so if you know the % water in the product the output will be very close to the input LESS the water content.
- The time to dry the product will depend on the form and depth and the amount of energy it can withstand. By optimizing the loading it is expected that you can achieve 1 complete batch per 24 hrs.
- The model number of the Cuddon Freeze Dryer indicates the ice trap capacity. This is the maximum amount moisture that the machine can process in one batch.
- FAQ: if product is 50% water can I double the input weight – Answer: In theory this is true but you may be limited by how much can physically fit into the product tray (plus increased depth slows drying)
Please fill this table with any known details of the product of interest
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Product Name to be dried
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Shape of product (diced, sliced, whole, puree, liquid, other)
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% moisture in product
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Desired Kg’s wet weight (input) per day
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Bulk weight in gm’s per litre or kg’s/M² @ 18mm height
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Maximum drying temperature product can withstand
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Freezing point ( or observations)
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% brix if known
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Known additives with product ( salt, alcohol, sugar, other)
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Number of days available to dry product
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Has product been dried by client before
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List any unusual characteristics of product
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