Environmental analysis tools usually show a series of natural conditions such as high and low, hot temperature, low pressure, sand and sand, and have great requirements for simulation. When an abnormality is detected, the laboratory should take measures to reduce the amount of flammable gas and avoid accidents such as explosions and explosions. Once an explosion occurs, the power system and protection of the test room are especially important. Adequate protection can reduce the loss of economic assets and avoid losses.
1. Control of Chamber
The cause of the explosion is a chemical reaction that is as violent as a fire. To prevent the combustion reaction of the sample in the high and low humidity laboratory during the test. At first, when a small amount of combustible gas is detected in the box, the process of introducing cool air into the high and low temperature test box is created, and the collection of flammable gases in the box can be kept. Within a safe range by introducing fresh air from outside. In extreme cases such as open fires and cracks in the box, the temperature in the box will rise significantly. At this time, fire extinguishing and control of the test box will be designed to control and extinguish the fire in the test box in time and prevent the fire and explosion from happening. Avoid damage to equipment, property and casualties.
When the laboratory’s combustible gas detection device detects that the combustible gas concentration in the room reaches 400 ppm, the air vents and air valves are opened. Air conditioning and ventilation begin to work at the same time, bring outside air into the equipment and reduce the total amount of combustible gas until the concentration of combustible gas returns below 400ppm; When fresh air continues for a certain period of time (the length of time can be set by an external timer), the air exchange device stops working and the laboratory does not stop for this process.
When the total gas concentration in the laboratory is 1000 ppm. The ventilation device continues to work, introducing fresh air and dissolving the accumulation of combustible gases. In this process, the lab stops working. However, the explosives protection system works well. If the concentration of combustible gas continues to exceed 1000 ppm, it cannot reduce the time, and the temperature in the room rises sharply, causing combustion or explosion in ‘exam room and the system of ventilation are closed at this time. The CO2 burner device is automatically activated, and high-pressure CO2 is directly injected into the test box through the nozzle in the test box, extinguishing the open flame in the test box, and reducing the temperature in the test box. . In this process, the laboratory is stopped and does not work, and the safety system and explosives of the laboratory work well to prevent the fire and explosion that cause damage to the test housing casing.
2. The chamber’s electrical system
In order to understand the explosion-proof early warning detection of high and low temperature water temperature test room, control the flow of combustible gas in the test room, automatically extinguish the fire when the fire and l exploded, some special tricks are necessary and electrical components.
Light sensor
A gas leak detection sensor is installed at the front end of the high and low temperature test chamber. The sensor accepts a pump extraction system. Sample and aspirate gas from the test room for detection. A sampling station is installed in the air circulation of the air in the field. The flammable gas sensor panel can set and display two alarm points. When the inflow of combustible gas is detected in the box beyond the alarm point, the combustible gas sensor will give a warning or alarm and issue an open circuit signal corresponding to the end of its output. After the PLC system detects that the input signal corresponding to Di is stopped, it performs the corresponding output function, to control the start of safety devices such as ventilation devices and damper systems.
Heating
In order to prevent fire, ordinary nickel-chromium metal cannot be used in the explosion box, but must be used for the heat exchanger, and the pipe and fin are stainless steel. A circuit breaker will not create an open circuit or cause a secondary fault such as a short circuit due to an external force such as an explosion.
Air conditioning
Air breathers, ventilation valves and dampers are installed on both sides of the door. 100 air hoses are connected to the building and a sample valve is placed in connection with the wall of the laboratory. When the air does not circulate, there is no gas exchange between the box and the outside. The ventilation valve and ventilation are placed outside the laboratory and covered with a cover. The wind speed of the fan should not be less than 5 m / min.
Automatic CO2 Jet Fire Fighting Device
In case of fire and explosion, the temperature in the high and low temperature test will rise significantly. This abnormal temperature change can be detected by a special temperature sensor, and the abnormal temperature signal is transmitted to the test room control system. The system injects CO2 by opening the solenoid valve. The high pressure CO2 tank and electric valve are placed on the outer wall of the box, and the nozzle is placed inside the box. In addition, “Manual switch” and “Cancel switch” are placed in the function display panel. When the user finds that there are bad conditions in the box that require the action of the CO2 burner device, he can manually press the manual switch. This manual adjustment is used with external timing links to prevent errors. The cancel switch can be pressed within a user-defined time to cancel the CO2 injection. It is to make that clear. If the safety protection door is opened, the CO2 burner will not work, to prevent the workers from being injured by the high CO2 pressure.
Determination of temperature
Two temperature sensors that can be moved anywhere in the box are equipped to detect the high temperature of the sample. When the high temperature of the sample is not good and higher than the preset temperature, the red light of the instrument and the hot light of the box are lit at the same time, and the tool stops to work and reduce the sample. Strength by joint strength test.
Emergency stop switch
When the operator finds something wrong in the box, quickly press the emergency stop button, stop the box, and cut off the secondary power of the test box from the AC controller, but the safety system (ventilation, CO injections). Etc.) are insensitive and work well.
Security Tools Display Panel
It is placed in the best position of the tool, that is, the correct position of the front of the cover. Air ventilation, manual automatic CO2 fire extinguisher, emergency stop switch, gas fire and negative temperature indicator light in the house are installed here.
UPS uninterruptible power
It is used to make the gas mask, ventilation device, CO2 fire fighting device, temperature indicating cover and the display board of the device. Security in the event of a power failure or when the stoppage is automatic. Of the test box, to ensure the normal operation of the safety system in the event of a power failure or explosion.
3. Structure of the Chamber
Building support
100mm channel steel is used to strengthen the outside of the box to prevent serious deformation and damage caused by a large impact on the box of the test box, fire spread and sudden accidents caused by hard materials. The cover plate is divided into small blocks to avoid the metal condition of the channel, which is convenient for the daily maintenance of the test box and the break in the assembly room.
Security Gateway
In addition to a large door with an observation window outside the box of the test box, a strong safety door will be installed. Be careful not to block the controller in the test box view window. The security door is also equipped with a limit switch for door opening detection. When the safety door is opened, the equipment box stops working; the test room can only work when the safety door is closed and the switch is closed.
View window
The size of the design of the observation window should not be too large. It must be round. The outer ring and the door of the test room can be fixed in double-layer stainless steel. In the case of glass, shatterproof glass should be used, and safety nets should be placed on the outside of the glass to prevent shards of glass from injuring people during an explosion.
Headspace
In addition to the thermal insulation plug, the door opening should also be equipped with a cable insulation cover and a small hole drilled in the insulation cover. A safety handle is attached to the thread. When the pressure in the box increases significantly, the cap can prevent the rubber stopper from coming out and harming people.
Installation Site
In order to avoid the increase of pressure around the test room when the high temperature and low temperature laboratory release the pressure. The test room installation area should be wide and free of obstructions around the test room. To prevent fire in the laboratory and secondary losses caused by interruptions, a distance must be kept between the top of the test box and the roof of the laboratory.
