1. When the screw chiller is installed or reused after a long-term outage, the cooling speed should be reasonable: it should be controlled at 8- 10℃ every day and kept at 0℃ for a period of time.
Second, the maintenance of screw chillers should pay attention to the collision and scraping of hard objects in use. Because it will cause the depression and corrosion of the library board, it will seriously reduce the local thermal insulation performance of the library.
Third, the maintenance of the sealing part of the screw chiller Because the assembled screw chiller is made up of several insulation boards, there are certain gaps between the boards. During construction, these gaps will be sealed with sealant to prevent air and moisture from entering. Therefore, some parts with seal failure should be repaired in time during use.
Fourth, the ground maintenance of screw chillers, generally small assembled screw chillers use heat insulation boards on the ground. Screw chillers should prevent the ground from storing a lot of ice and water. If there is ice, you must not use hard objects to knock and damage the ground when cleaning.
Screw machine maintenance:
First, demoulding, sterilization and disinfection of screw chillers
Cooking materials and foods frozen by screw freezers contain some fat, protein and starch. The existence of these nutrients will make molds and bacteria multiply and grow in large numbers.
In order to do a good job in hygienic management of cold storage and ensure the quality of cold storage of food and cooking materials, it is necessary to carry out hygienic disinfection of cold storage regularly.
In order to prevent mildew, kill mildew and disinfect screw chillers, acid disinfectants can be used first. The bactericidal function of acid disinfectants is mainly to coagulate protein in bacteria. Commonly used disinfectants are lactic acid, peroxycaproic acid, bleaching powder and formalin.
Second, the method of eliminating the peculiar smell of screw chillers
1 Causes of Odor in Screw Chiller
The so-called peculiar smell means that the cooking materials and food in the screw chiller produce an abnormal smell through physical and chemical changes under the influence of external factors, and this smell will attach to the walls, ceilings, equipment and tools of the screw chiller over time. Generally speaking, there are several reasons for the odor in the screw chiller: the screw chiller has an odor before entering the food.
Before the screw chiller, food is spoiled, such as spoiled eggs, meat, fish and so on.
Screw freezers that have stored fish have stored meat, eggs or fruits and vegetables without cleaning, resulting in odor infection and deterioration.
Poor ventilation and high temperature and humidity of screw chillers lead to a large number of mold reproduction and a musty smell.
The leakage of the refrigeration pipe of the screw chiller causes the refrigerant (ammonia) to corrode into the food, thus producing peculiar smell.
The temperature in the screw cooler does not drop, which leads to meat deterioration and corruption. This often happens when fresh meat is not frozen and then transferred to the warehouse for storage.
There are different smells of food in a screw chiller warehouse, which leads to food odor and mutual infection.
2. Prevent the screw chiller from generating peculiar smell.
The food stored in the screw freezer must be inspected and stored in the warehouse, and must not go bad.
Before purchasing, the warehouse of screw chillers should have no peculiar smell. If there is an odor, it must be treated technically to eliminate the odor before use.
At ordinary times, it is necessary to strengthen the maintenance of refrigeration equipment, and it is strictly forbidden to dump it indiscriminately to prevent pipeline damage and refrigerant leakage.
In the process of food cold processing, the screw chiller warehouse must keep a certain temperature, and frozen food must not be transferred or stored. If the temperature of the screw chiller warehouse cannot drop, it is necessary to find out the reason and carry out food processing after elimination.
Screw chillers are not allowed to mix and store food that infects each other. Compressor is a kind of screw chiller with refrigeration effect. The power is larger than that of scroll type, and it is mainly used for central air conditioning system or large industrial refrigeration.
Principle of screw chiller: The screw chiller is named after its key component-compressor adopts screw, and the unit is made of gaseous refrigerant from evaporator. After adiabatic compression by the compressor, it becomes a high temperature and high pressure state. The compressed gas refrigerant is cooled and condensed into the same pressure in the condenser, and becomes a liquid refrigerant after condensation, and then expands to a low pressure through the throttle valve to become a gas-liquid mixture. Among them, the liquid refrigerant with low temperature and low pressure absorbs the heat of the cooled substance in the evaporator and becomes a gaseous refrigerant again. The gaseous refrigerant re-enters the compressor through the pipeline and starts a new cycle. These are the four processes of refrigeration cycle and the main working principle of screw chiller.
What maintenance does the soft bed have to prevent dirt such as dust and dander from polluting the skin? Most families will lay mattresses on it, but they ignore that the mattress itself will hide evil people and shelter evil people. After a long time, bacteria, dust mites and so on will enter the bottom of the mattress. The best way is to turn the mattress every 3 ~ 4 months, either from beginning to end or up and down. When changing bedspreads and sheets, clean the residual dander and hair on the mattress with a vacuum cleaner or a slightly wet rag. Secondly, avoid standing on the bed at the same time, jumping or other behaviors with excessive local pressure, so as to avoid elastic fatigue of the springs in the mattress. Finally, avoid lying down directly after taking a shower or sweating.
What are the maintenance methods of CNC machine tools? With the development of science and technology, the automation and intelligence level of modern machinery manufacturing industry is getting higher and higher, and more and more CNC machine tools are applied to manufacturing industry, which promotes the development of modern machinery manufacturing industry. The automation and intelligence of CNC machine tools are high, and the maintenance of CNC machine tools also has high technical requirements. In daily use, we should not only strengthen the rational use of CNC machine tools, but also adopt scientific and reasonable maintenance methods to ensure the normal use of CNC machine tools. Good maintenance is the guarantee for the smooth production of enterprises. CNC machine tools are expensive. Maintenance in the process of use is conducive to reducing the loss of CNC machine parts, improving the service life of CNC machine tools and ensuring the normal use of the machine tools. At the same time, good maintenance effectively reduces the mechanical failure of CNC machine tools, reduces the probability of production safety accidents, and ensures the safe production of enterprises.
1, do a good job in the management of numerical control system, and formulate a reasonable maintenance system.
CNC machine tools have high requirements for temperature, humidity and gas in the workplace. In the process of use, we should do a good job in the management of CNC machine tools and formulate a reasonable maintenance system. To do a good job in the maintenance of CNC machine tools, enterprises need to formulate a reasonable maintenance system and perfect operating procedures, and update the existing systems and procedures in combination with the development of technology and actual needs to keep pace with the times. At the same time, enterprises should do a good job in the management of CNC system, strengthen the anti-impurity management of CNC system, clean up the dust and impurities in CNC machine tools in time, and provide a clean workplace for the use of CNC machine tools; Do a good job in cleaning the ventilation system of the CNC cabinet, clean the ventilation system in time, ensure the heat generated by the CNC machine tool to be distributed in time, and provide guarantee for the normal work of the CNC machine tool.
2, do a good job of mechanical system maintenance.
CNC machine tools play an important role in mechanical production, and the maintenance of CNC machine tools has been paid more and more attention. The maintenance of CNC machine tools has become an important task in the industry. To do a good job in the maintenance of CNC machine tools, we should strengthen the maintenance of mechanical systems, mainly including the maintenance of main transmission chain, hydraulic system, pneumatic system and machine tool accuracy. Do a good job in maintaining the main drive chain, regularly adjust the tightness of the main drive belt, check the temperature range of the constant temperature oil tank lubricated by the main shaft, replenish engine oil and clean the filter; As the power system of CNC machine tools, the hydraulic system should be inspected regularly, including oil in the oil tank, cooler and heater, hydraulic components, filter elements and other hydraulic system components. Enterprises should do a good job in mechanical system maintenance, strengthen the investment in mechanical system maintenance, and provide hardware guarantee for the normal use of CNC machine tools.
What are the maintenance methods of the card seat sofa? The left and right sofas remind you: 1. It is recommended to gently wipe it with a soft rag and detergent every month, then clean it with clear water, dry it with a dry rag, and spray maintenance wax such as Bellevue. 2. In case of heavy oil stain after long-term maintenance, you can first clean it with Mr. Wittmann, then wipe it with detergent, wipe it with warm water after wiping, and finally dry it with a dry rag and spray maintenance wax; 3. Do not scrape the leather surface with a knife, but wipe the leather surface with a hard rag to avoid damaging the leather surface and affecting its service life; 4. When there is dirt on the leather surface that is difficult to remove, never wipe it with solvents such as gasoline, xylene and rosin water. Prevent leather from fading; 5, if the appearance is not scratched or scalded, you can contact the manufacturer to express the same color leather bonding or changing sets to prevent the wound from getting bigger.
What are the precautions for the maintenance of screw barrel? 1. Do not start the machine when the barrel does not reach the preset temperature. New electric heating generally requires that the temperature reaches the set value for 30 minutes before operating the screw.
2. If the machine stops for more than half an hour at a time, it is best to close the discharge port, pat the materials in the barrel clean and set the heat preservation.
3. Avoid foreign matter falling into the barrel to damage the screw and barrel. Prevent metal fragments and sundries from falling into the hopper. If recycling materials are treated, a magnetic hopper should be added to prevent iron filings from entering the barrel.
4. When using anti-salivation, ensure that the plastic in the barrel is completely melted, so as to avoid damaging the transmission system parts when the screw retreats.
5. Avoid idling and slipping of the screw.
6. When new plastics are used, the remaining materials of steel cylinders should be cleaned. When using POM, PVC, PA+GF and other materials, reduce the degradation of raw materials as much as possible, and wash them with PP materials in time after stopping using them.
7. Avoid mixing POM and PVC into the barrel at the same time, which will react at the melting temperature and cause serious industrial accidents.
8. When the molten plastic is found to be abnormal or discolored, and the product is fragile, adjust the temperature to confirm whether the temperature sensing line of the heating ring works normally, and check whether the screw and the rubber-passing head assembly are damaged.
9. When assembling, disassembling or replacing the nozzle, screw head and flange, the threaded surface of the bolt should be coated with high-temperature anticorrosive paste for future disassembly.
Screw, rubber head, rubber ring, meson, nozzle, flange and barrel constitute the heart of injection molding machine, which determines the processing quality and efficiency and must be kept in good working condition. First of all, necessary measures should be taken to prevent non-plastic fragments from mixing into plastic raw materials. Secondly, we should pay attention to check the correct clearance between the screw and the barrel and between the retaining ring and the barrel. The normal gap should be able to seal the plastic backflow and produce the shearing action required for plasticization. When it is found that the melting action is slow, the melting material has spots and black spots, or the product is unstable, the wear of the screw, retaining ring and barrel should be checked.
What are the maintenance methods of loader electronic scales? 1. The electronic scale of Dacheng loader should be preheated when used, and the boom should be lifted 5- 10 times to preheat the oil pressure and sensor to normal working temperature.
2. In the process of operation, when lifting the tipper, the joystick of the boom should be controlled at the rearmost position, that is, the tipper is at the rearmost end. 3. The boom system should be strictly lubricated to reduce the friction coefficient of the boom.
What are the maintenance precautions for screw compressors? I. Daily maintenance items:
1, check the empty filter element and coolant level;
2. Check whether the hose and all pipe joints are leaking;
3. Check the records. If the wearing parts have reached the replacement cycle, they must be stopped and replaced;
4. Check the records. When the exhaust temperature of the main engine reaches or approaches 98℃, the oil cooler must be cleaned.
5. Check the records. If it is found that the pressure difference of the separator reaches more than 0.6BAR (limit 1BAR) or the pressure difference begins to decrease, stop running and replace the separation core;
6, check the condensate discharge, if found that the displacement is too small or no condensate discharge, must stop cleaning water separator.
Second, the monthly maintenance project:
1, check the surface of the oil cooler and clean it if necessary;
2. After cleaning the cooler;
3. Wash the water separator;
4. Check that all wires are connected and fastened;
5, check the ac contactor contact;
6, clean the dust on the surface of the motor suction port and the surface of the shell;
7. Clean the oil return filter.
Third, quarterly maintenance projects:
1. Fill the main motor with grease;
2. Clean the main motor and fan motor;
3. Replace the coolant;
4. Replace the oil filter element;
5. Clean the oil cooler.
Application of screw compressor;
1. Screw air compressor: mainly used in aerodynamic field to drive various pneumatic tools. Due to the development of oil-gas separation and gas purification technology, it is increasingly used in applications that require very high air quality, such as food, medicine, cotton spinning and other industries, occupying many markets of oil-free air compressors.
2. Screw process compressor: used to compress gases in various process flows, such as carbon dioxide, ethylene, methane, hydrogen, natural gas and torch gas.
3. The air compressor is changed to process use: this type mainly changes the rotor of screw air compressor to process gas compression. This kind of machine is often low-cost and limited, and can only be applied to a certain gas.
What are the maintenance methods of full-color LED display?
It is necessary to cut off the power supply when the weather is bad.
Indoor LED display screen is not allowed to touch any liquid.
Outdoor LED display screen should be waterproof when installed to prevent rain from directly soaking on the back of the screen.
Electronic products and machines, etc. Everyone has a life. Try not to work 24 hours a day.
What are the contents of automatic door maintenance?
1. Clean up the oil and dust in the cabinet and check the wear and tear of all parts of the automatic door.
2. Check the position deviation and screw tightness of the automatic door.
3. Check the tightness of the belt.
4, check the controller for motor output, switch door width, speed, braking and so on and so forth to check whether the voltage parameters are normal.
5. Repair and replace the damaged parts of the automatic door.
What are the maintenance methods of lamp posts?
First, standardize operating procedures, and strictly prohibit illegal operations.
Second, the maintenance and replacement of high pole lamp
1. In the process of retracting the wire rope, on the one hand, check the appearance of the wire rope, on the other hand, pay attention to whether the wire rope is overlapped, twisted, corroded, broken and severely stressed. Check whether the sliding parts are flexible and reliable.
2. Replace damaged light source equipment, cables, etc. , check whether all fixing bolts are loose, firm, safe and reliable, and whether positioning pins and automatic hooks are flexible and reliable. , replace the seriously corroded.
3. The motor, gear box and other transmission mechanisms fixed at the bottom of the lamp post should be closed and covered as far as possible to prevent the coil insulation from being damaged by moisture. Check whether the oil in the gearbox is sufficient, and whether the oil is black or has impurities. The transmission mechanism of mobile motor should be placed in a dry place, and its insulation resistance (not less than1mΩ) should be tested by shaking table before operation.
4. The AC contactor, thermal relay, travel switch, command controller and other control appliances in the control circuit of the high pole lamp should be thoroughly and carefully checked before operation. If there is any problem, the electrical components should be replaced as soon as possible, and it is strictly forbidden to operate in spite of illness.
5. Before the rainy season every year, the grounding protection device and lightning protection device of high pole lamp lighting facilities must be routinely inspected and the grounding resistance must be tested. If the grounding resistance value cannot be reached (it should be less than10Ω), it should be handled in time.
6. All the above maintenance contents must be recorded in an account.
After the maintenance work is completed, the electrical parts and lifting transmission mechanism of the high pole lamp lighting facilities should be thoroughly inspected again. Before leaving the site, the lamp board can be hoisted and directly hooked.