Micro-freeze preservation - common method
1. Adding ice or salt mixture The micro-frozen ice salt mixture is one of the most common simple refrigerants. They can absorb large amounts of heat in a short period of time to cool the catch. Ice and salt are all non-toxic and harmless to aquatic products. The price is low and they are safe and convenient to use. Especially when the two are mixed together, not only does the ice melt absorb heat, but the dissolution of salt also absorbs heat. The more salt added to the ice, the lower the resulting temperature, but adding too much salt can easily penetrate the fish and affect the taste of the fish. To achieve a frozen temperature of -3°C, add 3% salt to the ice.
2. Cooling and chilling The wind cooled by the chiller is blown to the catch so that the surface temperature of the fish reaches -3°C. At this time, the inside of the fish is generally at -1 to -2°C, and then the cabin temperature at -3°C. The China Depository has the longest preservation period of up to 20 days. The disadvantage is that the surface of the fish body is easy to dry. In addition, a refrigerator is needed.
3, low-temperature salt water micro-freezing low-temperature salt water has the advantage of faster cooling than air, usually the cooling temperature is -3 ~ -5 °C, the salt concentration is controlled at about 10%, these two points with the aforementioned cooling Seawater preservation is different. The specific operation is: first put the salt into the seawater and mix it with about 10% concentration, then turn on the chiller to cool the brine to -5°C, and then put the catch in salt water to cool to the surface temperature of -5°C. At the time (the temperature inside the fish is -2 to -3°C), it is transferred to a preservation tank pre-cooled to -3°C.
The brine concentration is the key to this technology, soaking time, brine cooling temperature should also be considered. If the brine concentration is large, -5 °C will not form ice, which is conducive to heat transfer and cooling. However, if the concentration of salt water is too large, the osmotic pressure of salt on the fish body will be increased, the fish will be salty, and some salt-soluble myoglobulin proteins will also be precipitated. From the point of view of aquatic products processing, the concentration of salt water is not easy to be too high, the brine cooling temperature is not too low, and the soaking time is not too long. If soaked with low-concentration brine, the required temperature cannot be reduced too low, and the cooling time is relatively longer. Considering the correlation of the three, combined with the cooling equipment and the cost of salt, and other factors, from experience that the best conditions for the three are salt water concentration of 10%, brine cooling temperature of -5 °C, soaking time of 3 to 4 hours.
2022 New Laser Distance Sensor
At the start of 2022, JRT introduce our customers a batch of new series laser distance measurer sensor(S92-20m, S91, BA6A-150m, BA6A-20Hz, M703A-8Hz, U81-10m etc.). Especially S91(RS485 interface and software Rx Tx protocol) and S92(RS232 interface) ip54 enclosure distance sensor model, custoemrs would like to use it in their industrial automation solutions,according to the ip54 waterproof protection level, well protect laser, Wide Voltage 5~32V(Optimize for industrial using), and easy-to-install.
If you are interested in JRT more laser measuring sensors, or you would like buy qty 2 quotation for trial basis, please welcome to contact us.
Kind regards
JRT Team
Chengdu JRT Main Ranging Modules: Industrial Laser Distance Sensors, Laser Rangefinder Sensor , Tof LiDAR Sensors.
laser measuring,infrared sensor,distance measurers,laser distance measurer,laser sensor
Chengdu JRT Meter Technology Co., Ltd , https://www.infrareddistancesensor.com