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Modular Penalized Solid Walk In And Drive In Environmental Chamber
Modular Penalized Solid Walk In And Drive In Environmental Chamber
Specifications
Brand Name :
Jianqiao
Model Number :
JQWI-2000
Certification :
CE
Place of Origin :
CHINA
MOQ :
1
Payment Terms :
T/T
Supply Ability :
300
Delivery Time :
5WEEKS
Humidity range :
20 % to 98% RH
weight(kg) :
Subject to the actual weight
Interior material :
Stainless steel plate sus304
Temp.Range :
-70℃/-40℃~85℃/120℃/150℃/180℃ customized
Temp Fluctuation :
±0.5℃
Design :
Modular
Packaging Details :
Wooden case
Description



Selecting an Environmental Test Chamer our company has just developed a new product, and now it is your job to select an environmental chamber to test it. The product must be tested at various conditions to
ensure its quality and reliability. Where do you start? What will determine your selection criteria? Price, quality, capabilities….

As with any major purchase, several items must be considered before making the final decision. Many people are tempted to buy on price only. However, as we know, you get what you pay for.
Quality, reliability, and service after the sale all add up to the value of your purchase. Value often is mistaken for low price. Over the life of the unit, that can become a costly mistake. Many different types of test chambers are available. Your application is primarily going to determine the type of chamber you need. The better you relay that information to your supplier, the better your chamber will match your needs. How big must the chamber be? What is being tested? Is it going to be air cooled or water cooled? What temperature range is needed? These are just a few of the necessary questions that must be answered before
purchasing a test chamber.

Chamber Types and Sizes
Reach-In Chambers Reach-in chambers vary in size from 0.5 ft3 to more than 70 ft3 (Figure 1). Virtually any environment can be created in these chambers.
Temperature, humidity, altitude, rain, solar and vibration are just a few.


Walk-In Chambers Walk-in chambers can be just big enough to step into or large enough to drive vehicles into.
There are two major types of walk-in chambers: modular and welded.

Modular walk-ins are constructed from preformed panels with urethane foam insulation, similar to walk-in refrigeration units you see at restaurants and supermarkets. The temperature and humidity range must be limited due to this construction. Normally, the maximum high temperature for modular walk-ins is between 100°C and 121°C. The humidity range typically is limited to 70°C and 95% RH.

Welded walk-ins are constructed like reach-in chambers. The internal chamber is welded together to withstand more extreme temperature and humidity ranges. This type of walk-in chamber also may withstand altitude conditions. Due to the additional labor to construct this type of chamber, it is much more expensive than a modular walk-in.


Thermal Shock Chambers
Thermal shock chambers come in many different sizes and configurations (Figure 2). These chambers can move the product from one temperature condition to another within a matter of seconds. Moving from a high temperature to a low temperature quickly thermally shocks and stresses the product. By performing these tests, the manufacturer can check the reliability of its process.

Temperature Range
The next major distinction is the temperature range in which the chamber will operate. Most manufacturers have a standard high temperature range of 177°C to 190°C for reach-in chambers and welded walk-ins. Temperatures up to 537°C can be achieved with special insulation and construction.

To cool the chamber, several options are available. The two major categories are expendable refrigerant and mechanically cooled. Expendable refrigerants are liquids/gases that can be injected directly into the space being cooled. As the liquid enters the chamber, directly or through a fin coil, it absorbs heat and flashes to a gas. The gas then is vented out of the chamber.
The two most popular refrigerants are liquid nitrogen (LN2) and liquid carbon dioxide (CO2). Cryogenic temperatures down to -184°C can be achieved with LN2. On the other hand, CO2 can only achieve temperature down to -68°C. Both of these gases are environmentally safe and can be vented to the atmosphere. It is imperative that the gases be vented outdoors. These gases displace oxygen, and asphyxia can occur if the chamber is not properly vented. Mechanically cooled refrigeration systems are similar to the type used in home refrigerators. They use a compressor and circulate a refrigerant around a closed-loop system. The ultimate low temperature required by your testing determines the type of refrigeration system needed.

Single-stage refrigeration systems typically can pull the temperature in the chamber down to -34°C. Some manufacturers rate their singlestage systems down to -40°C. However, due to the refrigerant used, there is very little cooling capacity available at -40°C.For continuous operation at -40°C and below, most manufacturers recommend a cascade refrigeration system.

Cascade refrigeration systems have two separate systems working to cool the chamber down to a low of -85°C. The firststage refrigeration system cools and condenses the refrigerant in the second stage. The secondstage refrigerant flows through an evaporator located in the chamber that cools the air. These systems can become very complex depending on the application A couple of years ago, a third refrigeration option became available. It is the patented, single-stage Refrigeration System that cools the chamber down to -45°C. It uses a common refrigerant and can operate continuously at -40°C. Since most low-temperature environmental testing is done at -40°C, it is a good alternative to buying a cascade system. It uses less energy (up to 40% less) and is less complex than a cascade system. There also are fewer parts compared to the cascade system, which means fewer items to fail over time. At warmer temperatures, the system also can handle large live-load conditions.

Humidity Range Humidity is probably one of the most misunderstood topics when it comes to environmental test chambers because the relative humidity (RH) percentage is temperature specific. For example, the amount of moisture in the air at 20°C and 50% RH is not the same as 10°C and 50% RH. As the temperature of air is decreased, its capability to hold moisture also is reduced. The standard temperature/humidity range for most chambers is 7°C to 85°C with 10% to 98% RH, limited by a 5°C dew point. The limitation of a 5°C dew point can be very confusing. Since the amount of moisture varies at every temperature, the chamber manufacturers use dew point to describe the RH limitation. Inside the chamber, there is a refrigerated coil controlled at 5°C or slightly below. Moisture in the chamber will be attracted to the cold surface and condense. The accumulated water is drained out of the chamber, lowering the relative humidity. The refrigerated coil is never below freezing so frost will not develop. The best way to understand this is to refer to
Figure 3. If you follow the bottom line of the standard range section of the graph, those temperatures and humidities represent the 5°C dew point.
Modular Penalized Solid Walk In And Drive In Environmental Chamber

For example, the lowest humidity level achievable at 20°C is 40% RH. At 50°C, the chamber will achieve 10% RH. It must be operated within the limits set by the manufacturer. Damage to the refrigeration
system can occur if points outside of the standard range are attempted. To achieve lower humidity levels, most manufacturers offer a low RH package. It normally includes a dryair purge system and refrigeration valves to allow the refrigerated coil to go below freezing. The low RH range in Figure 3 is achievable when the dry-air purge and frozen coil are activated. There is a potential for the coil to accumulate frost at these conditions. However, the dry-air purge helps to offset this by maintaining a positive pressure in the chamber and sublimating some of the accumulating frost off the coil.

Temperature Change Rate The requirements for temperature change rates continue to get faster and faster. It is not uncommon to see a 10°C, 15°C, or 20°C/min Figure 3. Standard Humidity Performance change rate specified. By incorporating faster change rates, total test time can be reduced. Products also can be thermally stressed at faster change rates to identify reliability problems. However, be careful assuming the part temperature is changing at the same rate as the air. Every chamber manufacturer has different airflow volumes inside their chambers. The airflow must have enough volume to support the refrigeration system. The typical air velocity in most reach-in chambers is approximately 100 ft/min through the work space. This velocity works well for steady-state and temperature cycling testing.

However, the part temperature will lag behind the air temperature with this airflow. Air velocity across the part should be much higher to keep it closer to the chamber air temperature during transitions. Typically, 500 ft/min or more is required to move the part temperature at a similar rate to the air temperature. It is a necessity in thermal shock applications to have airflow this high.

For most temperature and humidity applications, the airflow in reachin chambers is adequate for the test. As the temperature is raised or lowered in the chamber, the air expands and contracts. Since the chamber is a sealed compartment with the exception of a small drain, the expansion and contraction of the air cause positive and negative pressure to be generated.

When the air temperature in the chamber is changed quickly (10°C, 20°C, 30°C/min), more than 0.25 psi differential can be created. This does not sound like a lot, but over a large surface like a chamber wall, the pounds of force can become large. For example, a 32 ft2 chamber has a side wall that is 38s × 50s (1,900 in.2) 1,900 in.2 × 0.25 lbf/in.2 = 475 lb of force exerted on the wall, this force actually will be exerted on all the walls. To offset this reaction, most manufacturers install some type of pressure-relief vent. The vents normally are closed to limit the infiltration of outside air during operation. When a fast transition is started, the vent either will draw in outside air for a pull-down or exhaust chamber air during a heat-up. By allowing the chamber to breathe, the force on the walls is greatly reduced. It still is not uncommon to see the walls deflect in or out during a fast transition. Since this movement stresses the construction of the chamber, it is imperative that the chamber be well built.

Modular Penalized Solid Walk In And Drive In Environmental Chamber




模型

JQWI - 08

JQWI - 12

JQWI - 16

JQWI - 25

JQWI - 34

JQWI - 40

内部尺寸(厘米)

200 * 200 * 200

200 * 300 * 200

220 * 350 * 210

300 * 400 * 210

340 * 480 * 220

400 * 500 * 220

形状尺寸(厘米)

230*360*240

230*460*240

246*520*250

330*560*250

370*660*270

430*660*270

体积(升)

8.0立方米

12立方米

16立方米

25立方米

34立方米

40立方米

温度范围

-70℃ / -40℃ ~ 85℃ /120 ℃ /150 ℃ /180 ℃定制

湿度范围

20% 至 98% 相对湿度

温度变化

±0.5℃

空间温度变化

±2℃

温度冷却速度

1℃/分钟或定制

温升率

3℃/分钟或定制

重量(公斤)

以实际重量一致

外部材料

疲劳式试验标准彩/冷轧钢板箱/覆膜金属板

内部材质

不锈钢板sus304

地板承重能力

定制

门

PWM控制冷端温度

控制器

TW DELTA PLC,7英寸或10英寸彩色触摸屏控制

配置接口

具有USB,WLAN,RS232端口,APP功能可选

矿工

法国Tecumseh或德国Bitzer品牌或Bock

电源

交流380V@50Hz













































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Modular Penalized Solid Walk In And Drive In Environmental Chamber

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Product Detail
Brand Name :
Jianqiao
Model Number :
JQWI-2000
Certification :
CE
Place of Origin :
CHINA
MOQ :
1
Payment Terms :
T/T
Contact Supplier
Modular Penalized Solid Walk In And Drive In Environmental Chamber

Guangdong Jianqiao Testing Equipment Co., Ltd.

Verified Supplier
1 Years
guangdong, dongguan
Since 2006
Business Type :
Manufacturer, Distributor/Wholesaler, Exporter, Seller
Main Products :
Three Zone Thermal Shock Chamber, Vibration Test Table, Shock Test System
Total Annual :
10million-15million
Employee Number :
>100
Certification Level :
Verified Supplier
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