Bulk milk coolers in the size range of 1000 Ltr to 2000 Ltr capacity are typically installed at a cluster of nearby villages. Milk must be chilled to 5 ⁰C or less within 3.5 hours from the start of milking. However, the milk takes about an hour to reach the milk collection center in a village cluster model. The primary challenges with traditional milk coolers are constant cooling rates, slow milk cooling, low milk quality and dependence on diesel generator during grid failure.
Traditional milk coolers have constant cooling rates even at different milk temperatures. However, bacteria growth is much higher at higher milk temperature. Increasing the compressor size is not viable as it results in milk freezing near 4 ⁰C.
In addition, the traditional systems are backed with diesel generators. The milk cooling cost on diesel is typically 1 – 2 INR/L as compared to 0.15 – 0.2 INR/L with grid electricity. The pilferage of diesel, maintenance after every 500 hours of run time and environment pollution are other few challenges associated with diesel generators. In addition, the BMC operator needs to be present at the milk cooling center until milk is cooled to switch ON/OFF the diesel generator. It results in several short cuts adopted by BMC operators such as leaving the milk between 7 to 10 ⁰C and cooling milk to 4 ⁰C just before it is lifted by the milk tanker.
The ideal solution would have higher cooling rates at higher milk temperature and lower cooling rates at lower milk temperature. It would also ideally have inbuilt energy storage to provide redundancy during grid failure.
Inficold is addressing these challenges with ice energy storage integrated bulk milk cooler. The compressor and ice energy storage are working in tandem to modulate cooling on the need basis. This system provides 300 % cooling rates of the installed compressor capacity at 30 ⁰C milk temperature, which rapidly cools milk to preserve its quality. The cooling automatically reduces to 70% of the installed compressor capacity at 4 ⁰C milk temperature, which reduces the chances of milk freezing. This is achieved without increasing the compressor capacity as compared to traditional milk coolers.
This system also has inbuilt cooling backup of a day. The system completely charges with about 10 hours of grid availability any time of the day. It is fully automatic and does not require user intervention, thereby streamlining the milk cooling process as BMC operator doesn’t have to wait to switch ON/OFF the milk cooler till milk is cooled to 3 ⁰C.
Inficold manufactures the entire system including thermal energy storage with SS304 material to meet high life expectancy and sanitary requirement of dairies.
Inficold is the first and only company which integrates these thermal energy storage bulk milk coolers with solar photovoltaic panels. Few of these units are currently operational in completely off-grid locations of Africa.