Freezing and thawing equipment "installation and use method" - Huaqiang Electronic Network

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Freezing and thawing equipment

structure:

The device consists of three parts: computer automatic control system, freeze-thaw test chamber, refrigeration, heating and brine circulation system.

1. Computer automatic control system: use paperless recorder to control and record temperature tracking and automatic recording at various points. The counting relay can arbitrarily set the required number of cycles and automatically display the number of completed cycles. The liquid supply solenoid valve, thermal expansion valve and pressure protection switch used in the refrigeration automatic control system are all selected from the world famous manufacturer Danfoss (DANFOSS). The control system has good control, display, recording, interlocking, fault alarm and other protection functions. All control components are in compliance with IEC international standards or GB national standard.

2. Freeze-thaw test chamber: The test box is made of high-grade Stainless Steel Plate, and the box body and the cover lid are filled with foamed polyurethane plastic for heat preservation, and the heat preservation performance is good.

3. Refrigeration system: It adopts the US imported condensing unit, the working fluid is F22, and the evaporator adopts the stainless steel heat exchanger produced by Alfa Lafa Company, which has the characteristics of small volume and high heat exchange efficiency.

4. The heating and cooling system is heated by a high-power three-phase heating pipe, and the pipeline pump is used to drive the cold and heat cycles.

Freezing and thawing equipment

Installation and use

1. After opening the box, check whether there is any damage caused by transportation vibration. The damaged part should be repaired before use.

2. The requirements of the installation site for the installation:

1 The air is to be circulated.

2 Keep away from heat sources, no direct sunlight, and prevent rain.

3 There should be appropriate space around the unit for easy operation and maintenance and air circulation.

3. The test period of the device is long, the power should be supplied by the dedicated line, the cutting voltage is stable, and reliable grounding is required.

4, power check; the direction of rotation of the pump and condenser fan is correct.

5. Place the 100×100×400 coagulation test piece into the test tube, and then immerse it in water at 15°C-20°C for 4 days, then remove it, wipe the surface moisture with a damp cloth, measure the weight, and measure the initial value of the horizontal fundamental frequency. . Then, the test piece is placed in the test piece cylinder, and the water level in the cylinder should always be kept higher than the top surface of the test piece by about 5 mm during the whole test.

6. Place the test piece tube into the test piece slot, where the temperature test sample tube is placed at the center of the test piece slot, insert the long lead sensor into the center of the temperature test piece, and place the short lead sensor on the temperature test. The outside of the barrel.

7. Turn on the power switch and the running switch and the machine starts working. The weight and relative dynamic modulus of the test piece are measured every 25 freeze-thaw cycles. When the relative dynamic elastic modulus drops to 60% of the initial value or the mass loss rate reaches 5%, it is considered that the test piece has reached the damage, and the corresponding freeze-thaw cycle number is used as the anti-freeze level of the concrete. If the test piece freezes and freezes to the predetermined number of cycles, and the relative dynamic elastic modulus or mass loss rate does not reach the above index, it can be considered that the tested concrete frost resistance performance has met the test requirements. The concrete durability coefficient can be calculated according to the number of freeze-thaw cycles and the corresponding relative dynamic elastic modulus.

Freezing and thawing equipment

maintenance:

1. Always check whether the condenser is clean, whether the oil level of the compressor is normal, and whether the indication of the pressure gauge is normal. If there is any leak, please ask the professional to replenish the refrigerant and lubricating oil in time.

2. After the external circuit is overhauled, pay attention to the steering of the water pump and the air cooler. If the reverse direction should be corrected in time.

3. If the temperature is very slow, check if the water content of the antifreeze is too much. If the water content is too much, the crystallization temperature will increase. In the test temperature range, it will become porridge, the temperature difference will increase, the cooling time will be prolonged, and even the temperature will not be cooled. At this time, you should replace the new antifreeze.