Based on the scale of production, the sterilization equipment used is divided into two categories:
The first category is the high-pressure, high-temperature (1.5 to 2 kg/cm2, above 125°C) sterilization tanks, which are suitable for use in regular edible mushroom factories. The cost of this type of equipment is between 20,000 and 100,000 yuan per unit, and the price depends mainly on the size of the model and the level of construction. In addition, the annual production capacity of 200,000 to 500,000 bottles (bags) of mushrooms, processing 300 to 500 tons of salted mushrooms edible fungi enterprises, but also must install 1 to 2 tons of high-pressure steam boiler.
The second category is different shapes of atmospheric pressure and room temperature sterilizing stove (furnace), less investment, safer, suitable for small-scale production by farmers.
(I) high-pressure sterilization equipment Different types of high-pressure sterilization equipment and its scope of application see Table 7-1.
Table 7-1 high-pressure sterilization equipment and its scope of application
The use of high-pressure steam equipment sterilization, should pay attention to the following 2 points:
One of the sterilizing tanks in the strains of vials (bags) arranged in the appropriate density, so that the steam is unobstructed, no dead ends.
The second is the sterilization tank cold air must be exhausted, through the steam; open the exhaust valve, with the temperature inside the tank rises. The cold air in the pot will be gradually discharged. When there is a large amount of steam from the exhaust valve, and then close the exhaust valve. After the sterilization is finished, let it cool naturally. When the pressure pointer back to 0 position, open the lid of the can 1/4 open, the use of residual heat baking cotton plug, to prevent the sudden cold condensation. Then remove it while it is still hot and send it to a clean cooling chamber for cooling.
(ii) atmospheric sterilization pot General farmers with atmospheric sterilization pot (Figure 7-4), its volume can be large or small, depending on the amount of production. Atmospheric cooker economical and practical, large capacity, can be built by themselves, because the sterilization temperature is not higher than 100 ℃, the nutrients in the substrate is not easy to destroy. However, the sterilization time is long and the fuel consumption is much. Atmospheric sterilization should pay attention to the following matters:
1. Sterilization of bags or bottles in the pot can not be squeezed, layer to layer with a layer of drawers or bag baskets to separate, to facilitate the uniform circulation of steam in the pot.
2. When the ignition of steam occurs, open the exhaust hole below to discharge cold air. When there is a direct steam discharge, you can close the exhaust hole, when the temperature rises to 100 ℃, start timing, and continuously maintain more than 8 hours.
3. Ignition before the pot and outside the water tank with enough water, in the whole process of sterilization to pay attention to the water level in the tin cans, to add water at any time to keep the siphon water pipe smooth, to prevent burning dry pot.
4. In the whole process of sterilization, the fire should be operated according to the fierce attack → constant temperature → slow down the program. That is, the beginning of the fire should be fierce, as soon as possible to reach 100 ℃, the time of 2 hours or so is appropriate to prevent the slow rise in temperature, too long, caused by raw materials sour; when the temperature rises to 100 ℃, to maintain a constant temperature, can not be high and low impact on the sterilization effect. When the sterilization time is reached and then attacked for a while, and then let the temperature inside the pot slowly reduced, when down to 60 ℃, before you open the door to take things.
(C) multi-functional steam stove steam stove combines the high efficiency of autoclave sterilization equipment and atmospheric sterilizing stove safe and cheap advantages, sterilization temperature between the soil steamer and autoclave, the general soil steamer sterilization temperature between 80 ~ 100 ℃, autoclave between 115 ~ 127 ℃, while the steam stove sterilization temperature between 100 ~ 103 ℃. Is the more applicable equipment for farmers, the price of about 3,000 yuan.
Multifunctional steam furnace for sterilization has three advantages: ① steam furnace small size, light weight, a person can push (with mobile wheels), can be in the bagging place in situ sterilization, eliminating the bag of material pots and pans out of the pain; ② fast heating, water capacity of 200 liters, burning ten minutes to produce steam. Comparison with the soil steamer, can save 30% of fuel; ③ a stove multi-purpose, in addition to sterilization of strains or bags, can also be used for steam protection inoculation, mushroom room culture material secondary fermentation, mushroom room and mushroom shed warming and humidification, mushroom body to kill the clear pre-cooking, preparation of saturated brine, kitchen cooking water, and so on.
Figure 7-4 Atmospheric Pressure Sterilization Kettle (Unit: cm)
When using steam oven for sterilizing, organize the ground near the place of bottling (bag) and lay a layer of bamboo poles or bricks, the purpose is to isolate the mushroom bottles (bags) from the ground and prevent the condensation from wetting when sterilizing. If the sterilization bag, can be loaded with iron baskets or woven bags, base into a ladder-type pile, generally 6 layers of code. Seed bottles can be sterilized in baskets. Steam oven sterilization can be extinguished once 2 to 3 tons of material. Yards of bags after the pile, covered with two layers of plastic sheeting, for insulation and then cover thatch or grass curtains. With bricks or heavy objects along the perimeter of the two layers of plastic sheeting and thatching pressure, to prevent the steam pressure to lift the cover. When ready, the steam furnace pipe into the bottom of the bag stack between the bamboo poles or brick gaps. Add water to the steam furnace to reach the standard water level. Check that the water level gauge and pressure gauge are normal. Coal fire burning 10 to 20 minutes, the furnace steam pressure up to 0.5 kg / cm 2, at this time to open the exhaust valve to the bag pile through the release of steam, 2 hours after the material temperature can reach more than 100 ℃. Multifunctional steam furnace for the use of air pressure of 0.5 kg / cm 2, more than this pressure is automatically deflated, safe and reliable. Warm fire coal consumption of 20 to 26 kg / hour, regular fire burning coal 6 to 8 kg / hour. The water consumption of peak fire is 90 kg/hour, and the gas production is 90-120 m3/hour. When the center of the pile temperature rises to 95 ~ 100 ℃, continue to burn 5 ~ 6 hours after the cease-fire, and then smothered 5 ~ 8 hours to uncover the cover, the sterilization effect is better. General sterilization 1500 ~ 2000 bags, about 60 kg of coal burning.