The piston is one of the main moving parts of the
engine, is composed of combustion chamber components. Engine Piston Parts,Engine Parts ,Car Engine Parts,Parts Of Engine,Piston Engine Parts ZhouShan HeCheng Machinery Co., LTD. , https://www.hcmarineparts.com
The pressure of the gas
piston through the connecting rod to the crankshaft, realize the change from
heat energy to mechanical energy.
The work condition is very bad, and the
temperature of 1400-1800 DEG C, and pressure
Up to 13MPa above the gas
contact, greatly alternating thermal stress and mechanical stress.
And by the
serious corrosion of gas, and under the condition of boundary lubrication and
cylinder wall friction and strong impact 1 times.
The piston in high
temperature, high pressure, strong corrosive gas contact so that it has enough
strength and hardness,
Heat resistance and good thermal resistance, high
fatigue strength and corrosion resistance. For high speed diesel Engine Piston
also requires light as far as possible.
In order to reduce the inertia
force.
Marine piston large low speed diesel engine of the crosshead is
usually combined.
The heat treatment process by normalizing and annealing,
and iron pearlite are ferrite organization, has good heat resistance.
Piston
alloy quenched and tempered steel has better heat resistance and corrosion
resistance. The skirt with nodular cast iron annealing treatment, with good wear
resistance.
Non-pollution celery cultivation technology in cold area
1 Variety selection and seed treatment 1.1 Variety selection Non-pollution celery should be selected for petiole length, solid, less fiber, high yield, good resistance, and strong resistance to diseases and insect pests. The seed quality meets the requirements of the GB16715.5-1999 standard. 1.2 Seed treatment After soaking the seeds with 48°C constant temperature water, soaking seeds for 30 minutes under constant stirring for disinfection, then removing them for 24 hours in cold water, washing them out, and mixing them with 5 times the volume of seeds. ,Into the clean water basin, place in 15 °C ~ 18 °C to see the light, flip 1 or 2 times a day to maintain the moist state of the yarn. Seeds can be sown when 30% to 50% of the seeds are exposed. 2 Seedlings and Seedling Management 2.1 Seedlings are usually raised in the nursery from late January to mid-February. The seedbeds are convenient for drainage and irrigation, loose and fertile soil, and have good fertilizer and water retention properties. The soil quality meets the NY5010 standard and is not planted in 2 to 3 years. The field plots serve as seedbeds. It is made of sorghum which is 1m wide, 6 to 10m long, 0.3 to 0.4m wide, and 0.15 to 0.2m deep. Decomposed organic fertilizer 25-30kg per square meter, NPK fertilizer (15-15-15) 100g, plus carbendazim 50g, deep-turning fine smashing, filling the bottom water, water infiltration, The seed that prompts the buds is evenly spread on the surface of the sorghum, and covered with fine soil 0.5-0.6cm. 2.2 Seedling management During the seedling period, the air was released at 20°C during the day, kept at 10°C during the night, and maintained at 12°C during the later period. The seedbed should pay attention to watering, and often keep the soil moist. After seedlings are treated with 0.2% urea, they are poured once every 10 to 15 days to promote seedling growth. Increase the amount of ventilation before planting, reduce the temperature, during the day 15 °C ~ 20 °C, 5 °C at night, in order to improve adaptability. Seedling weeding, before sowing seedlings, use 33% weeding pass 100 ~ 150 mL, watered 60 ~ 80kg, evenly sprayed bed can be. 3 Planting 3.1 Selecting land, site preparation, and fertilizing celery Honda should select land that is loose and fertile, has good drainage and irrigation conditions, is free of pollution sources, and has convenient transportation. The soil meets the requirements of the pollution-free food NY5010, and is plowed immediately before winter and is applied every 667m2. Decomposed farmyard fertilizer 3000 ~ 5000kg, three yuan compound fertilizer (15-15-15) 40 ~ 50kg. Deeply turn 20cm to fully mix the soil and fertilizer. 3.2 Planting When the outside temperature reaches -5 °C or above, the shed can be baited. When the seedling height is 15 to 20 cm and there are 6 to 7 leaves, it can be planted. During the colonization, the seedlings were taken from the soil with a guaranty shovel, and the individual plants were colonized. The number of seedlings per 667m2 was 35000 to 40,000. The depth of colonization should be the same as the depth of seedlings on the seedbed to expose the heart. 3.3 Field management The temperature in the awning starts to rise at 20°C, and the shade is maintained. The temperature is maintained at 15°C to 20°C, and not less than 10°C at night. Immediately after planting watering, 3 ~ 5d after pouring 1 time Huanmiao water, 10 ~ 15d per 667m2 chase urea 5kg. Each time after 20 ~ 25d topdressing once, every 667m2 chase urea and potassium sulfate 10kg each. Stop fertilizer and watering 10 days before harvesting. Topdressing should be carried out between rows to prevent foliar sprays to reduce nitrate accumulation. There must be no excessive humidity in the shed to prevent disease. 4 Prevention and control of pests and diseases Pests and pests of celery are subject to the principles of agriculture, physics and biological control, supplemented by chemical control. By selecting good disease-resistant varieties, nurturing strong seedlings, strengthening cultivation and management, and scientific fertilization, create an environment conducive to the growth and development of celery. The harmful biohazards to celery will be controlled below the permissible economic threshold to achieve safe, high-quality, harmless celery. If the pests and diseases occur severely and chemical pesticides are used, they must be selected in accordance with the requirements of pollution-free foods GB4285 and GB/T8321 pesticides, spraying according to regulations.