Danfoss scroll compressors MLM076 ensure the healthy growth of king oyster mushrooms

Friday, 25 October 2013

When Danfoss sales manager Li Zhiwei returns to his home village in Henan, he finds people working energetically to build a large king oyster mushroom growing house. High-performance and reliable equipment developed with Danfoss components is the foundation for project success.

"The rain keeps falling, and I don't know that spring has gone. Only when the sky clears do I feel that I am deep into summer.” Henan in July is a land of blazing sun and scorching days. As a result of temperature requirements, the cultivation of traditional king oyster mushrooms has had to wait until the fall of each year. But the application of modern technology has brought changes. 

Edible fungus is a 21st-century sunrise industry. It is high-protein and low-fat, and it involves no contamination or environmental pollution. It also boasts medicinal benefits. Sales to consumers increase with every passing year. At present, all edible fungus cultivation is being produced on a commercial basis. Mixing and cooling, spawn running, and fruiting are carried out in a refrigerated environment. Accurate temperature and humidity and CO2 concentration can ensure good fruiting quality and yield.

The project that is currently under construction has already made use of more than Danfoss scroll compressors MLM076 for refrigeration, as well as thermal expansion valves (TG7.5), pressure switches (KP15), and other line components. Shanghai Yicheng Refrigeration Equipment Co., Ltd., an equipment manufacturer, has selected them for its refrigeration units dedicated to this typical fungiculture application.

According to the end-user, the reason for choosing Shanghai Yicheng was their professional performance within the industry. The end-user was also deeply impressed by the high quality of the refrigeration units. Mushroom growth is very delicate. If the temperature is too high, then unwanted fungus will sprout and diminish its commercial value. Temperatures that are too low will suppress growth and lengthen the growth cycle. Excessively low humidity will cause edible fungus to shrink and bags to fall off, with low yields and deformities. Insufficient moisture inhibits growth, but too much moisture will cause rot and even death. An excessively high concentration of CO2 will inhibit the growth of the fruiting body. It is necessary to reduce the CO2 concentration by supplying fresh air through ventilation. But if it is too low, fruiting bodies will become loose and soft. Thus, high-performance, high-reliability equipment is the foundation for project success.

"Shanghai Yicheng chose Danfoss for the recognized superiority of the Danfoss refrigeration compressors and valve products”, says Mr. Liu Weidong, General Manager Shanghai Yicheng. Mushroom growing buildings constitute an environment that presents severe challenges to the reliability of compressors and valves. The system's evaporating temperature is not very low, but the temperature accuracy requirements are very high. Long-term operation and humidity control in an environment where lines and components easily corrode place very high expectations on all parts of the refrigeration system.

Danfoss scroll compressor MLM has been optimized for freezing and cooling conditions and offers below benefits:

• Highest efficiency in the industry: under EN12900 HBP condition, COP of MLM076 is at least 3% above other alternative scrolls and 8% above semi-hermetic.
• High reliability: very simple press-fit assembly technique contributes to 1/3 less components and half the hermetic welds of competitive scrolls, thus achieving less risk of compressor failure.
• Compact design: with hybrid scroll profile, the displacement of MLM076 increase by 13% without enlarging scroll set size.
• Less weight: MLM076 only weighs 45kg, 26% and 68% lighter than alternative scrolls and semi-hermetic respectively.

Danfoss’ valve parts have always been the best in the entire refrigeration and air-conditioning industry. Its expansion valves make use of stainless steel capillary tubing and temperature sensors which are to a certain extent corrosion resistant. Patent laser welding technology, unique double-diaphragm design, precise control curves, and perfect manufacturing processes—all of these ensure regulated flow results and system reliability.

Lucky king oyster mushrooms! With such professional care, they are sure to grow healthy! Li Zhiwei has already made an appointment with his hometown. The next time he comes to visit, he will definitely be carrying a large bamboo basket on his back in the expectation of becoming a modern-day “mushroom picker”! Let us continue to care for the oyster king mushroom refrigeration project of this customer.

Danfoss components selected for Shanghai Yicheng Refrigeration Equipment


  Mycelium culture period     Fruiting body growth period    
  Temperature  Relative humidity% Co2 volume fraction% Temperature Relative humidity% Co2 volume fraction %
King oyster mushrooms 20-22 60-70 ≤ 2.2 14-18 80-90 0.2
Enoki mushrooms 18-20 60-70 ≤0.2 8-12 80-90 0.06-0.2
Oyster mushrooms 24-26 80   13-15 85-90 ≤2.2
Lion's mane mushroom 21-24 70-80   15-17 80-90  
Champignon mushroom 22-24 60-65 ≤1 13-16 80-90 ≤2.2
Shiitake 24-26 60-70   18-21 80-90