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E-mail
mariahan@sjialab.com
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Phone
15869641262
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Address
Building 4, Tianyi Health Industry Park, High tech Industrial Development Zone, Cixi City, Ningbo (at the northwest corner of the road)<1-3>; <1-4>
Ningbo Shuangjia Instrument Co., Ltd
Questions about choosing a food freeze dryer
Date: 2023-05-24Read: 9
1. How often is freeze-drying completed?
This depends on many factors: product category, density, volume, ambient temperature, and the maximum acceptable endpoint temperature of the product. For example, after slicing lean meat (with a thickness of less than 8mm), the time is about 18 hours; Slicing strawberries takes about 24 hours, and it may take more than 30 hours to achieve good results without slicing.
Biological products depend more on the ingredients of their formulation, such as low freezing point, glycerin, excipients, protectants, etc. It is difficult to determine the time. Some products can be completed within 24 hours (cosmetic freeze-dried powder), while others require 72 hours or longer.
2. What is the energy consumption of the freeze dryer?
The installed power we usually provide is not the energy consumption of the entire freeze-drying process. The energy consumption of the refrigeration system varies greatly throughout the entire process, from the initial maximum load to only 1/4 of the initial load in the later stage;
The intervention of the heater is not continuous, but intermittent output based on temperature requirements;
The energy consumption of a vacuum pump is also the same as that of a compressor. Basically, after the vacuum is removed, the energy consumption is only within 1/4 of the initial operation;
The energy consumption of freeze-drying machines for biological products and pharmaceuticals is generally higher than that for food, because the freeze-dried products of the former are expensive and have high quality requirements. To ensure sufficient redundancy in the system, refrigeration systems, circulation systems, heating systems, etc. will have more redundancy;
The energy consumption of food freeze dryers is a concern, so the system should adjust its configuration as much as possible according to the freeze-drying or production products. Do not pursue the beauty of parameters (such as water capture capacity) and ignore the production energy consumption. For manufacturers, the increase in energy consumption will not actually increase the cost much.
Based on operational experience, large freeze-drying machines adopt an intermediate thermal oil mode. For food products, freeze-drying machines with an area of 20 square meters or more generally have a water capture cost of 2-2.5 kWh of electricity per kilogram of water.
Our H series does not use intermediate heat transfer oil in its structure, resulting in only one-third of the energy consumption when using heat transfer oil; SJIA-20H is a very suitable choice for small-scale production and pilot testing in the food industry.
3. What is the quantity of products that can be freeze-dried in one go using a freeze dryer?
The amount of water captured is a good reference indicator, which refers to the water that can be captured and sublimated by the freeze-drying machine. The water comes from the product and is calculated based on its density, volume, etc. So different products must be different, for example, the load capacity of a truck, a 10 ton truck carrying fruits and cardboard boxes must be different.
The standard for users to make good judgments is to arrange the product on a plate and calculate the weight based on the area, such as fruit, sliced, and placed 1 square meter to see how heavy it is. Because the general water capture design of a freeze dryer is based on the area of the shelf, typically capturing 10 kilograms of water per square meter; Being too high is not very useful, but rather increases energy consumption; If users want to freeze dry light goods with low moisture content, reducing the water capture range will result in better energy consumption, which is more energy-efficient and achieves the same results.
