Walk in salt spray chamber is mainly to do surface processing for various materials, including paints, electroplate, inorganic and anti-rust oil, and after anticorrosion treatment, test the corrosion resistance of their products. Widely used in the aerospace industry, automobile electronics, electronic electrician, mobile phone digital, plastic products, metal materials industries.
Equipment operating conditions
(1) the environmental temperature 5 ℃ ~ + 28 ℃; Environmental humidity: no more than 85%; It is well ventilated (it is best to have separate room with exhaust fan, with sewage and waste water within 1 meter distance)
(2) air source requirements: the pressure is greater than 0.4mpa and the rated displacement is greater than 2m3/ min
(3) power supply requirements: AC380 (+ / - 10%) V/50HZ; Three five lines; Pre-installed capacity: about 15kW; The power cord of the equipment is 5 meters
(4) water source requirements: nearby tap water is convenient to add water and flush inside the equipment, and distilled water or deionized water is also available.
Feature
1. Test chamber body
1.1 the box is composed of a combined type (the box is composed of PP plates with a resistance of 80 degrees), which directly constitutes a sealed test space. The box can be automatically insulated within the specified temperature range, and it can meet the requirements of layout of the fog-forming device, gas path, salt water supply pipeline and opening and placement of the temperature sensor. Due to the salt spray test, there are high temperature (35 ~ 50 ℃), and strong corrosive, therefore making salt fog test box body material should have a certain resistance to corrosion and heat-resistant properties. In order to meet the need of corrosion resistance, easy cleaning, temperature resistance and certain strength, PP board is adopted for the inner and outer box materials of the room. According to the length, openness and height of the room, composite salt fog laboratory is prepared in advance in the factory.
1.2 the salt spray test stipulates that the droplet formed by spray should not drip on the test piece, and the Angle between the top of the test room should be at a certain Angle, generally between 110 and 120. The droplets thus formed flow along the spire to the sides of the laboratory.
The whole body of the chamber shall be treated with water leakage and fog leakage.
1.3 door: one of the keys to the chamber. The requirements for it are: (1) it is convenient for the sample to enter and leave; (2) it is well insulated; (3) it is light and handy to switch. Fourth, good sealing, salt - free fog leakage.
2. Heating system
The temperature of the chamber body is heated to the required temperature through heat dissipation by adopting corrosion-resistant titanium alloy heating tube.
3.1 the laboratory adopts airflow spray, so the air supply system is needed. The function of the air supply system is to supply fresh, clean and moist hot air with pressure for the salt fog laboratory. The air compressor is used as the air supply source in this room (provided by the user), and the environment atmosphere is compressed into high-pressure air by the air compressor and then enters the storage tank, which is connected to the designated position through the gas pipeline.
3.2 as the spray pressure only needs 0.07~ 0.14mpa, the filtered air needs to be reduced to 0.2-0.3mpa in the first stage. The second stage shall be adjusted to 0.07~ 0.14mpa according to the size of fog, so that the spray pressure spurted by the nozzle can be within the specified range.
3.3 salt spray test requires that the air entering the laboratory should have a certain temperature and humidity. Therefore, a set of heating and humidifier, namely air saturator, should be added before compressed air enters the chamber. The temperature of saturator is controlled by the main control board, and the spray pressure and temperature are adjusted according to different ambient temperature and test temperature. The saturator is a pressure vessel with a pressure resistance of more than 3Kg and made of stainless steel. It is provided with water level gauge, water inlet valve, exhaust valve, blow-off valve, sensor test hole, etc. The tee is connected to the pipeline leading to the nozzle and to the pressure gauge. After the compressed air enters the saturator, it is filtered again through deionized or distilled water. It is then mixed with the steam generated from deionized or distilled water in the cylinder to make the air entering the nozzle close to the test temperature in the box, clean and moist. The piping material of the air supply system is PU pipe with pressure resistance
3.4 saturator water supplement: due to the flow of air in the saturator is hot and humid air, can take away part of the water vapor, working long hours can constantly consumption of water, need to replenish water regularly, in addition, due to the spray conditions, saturator with pressure, can't get into water, had to temporarily stop gas supply, water is very slow, in this case should be: in the saturator Settings, electromagnetic valve, electromagnetic valve for water can also be manually adding water.
4. Salt water supply system:
4.1 continuous airflow spray, continuous automatic replenishment of salt water is essential. The salt water supply system is designed for this purpose. The salt water tanks are usually placed on the upper part of the chamber body.
4.2 in order to make the temperature of the salt solution entering the nozzle close to the indoor temperature, a heater should be installed in the salt water supply tank. Due to the corrosion performance and high required temperature of the salt water, the salt water supply container is a PVC container, which is controlled with a special temperature controller to make the salt water entering the nozzle meet the requirements.
5. Spray system:
5.1 the function of the spray is salt water from the salt water supply system using air supply system of high pressure air from the nozzle at the exit of high-speed jet ejector effect, through the siphon principle after mixing brine is sucked up and air mist fan dispersion, due to the fog contains some not atomized droplets of water, so the ejective mist airflow cannot be directly introduced into the laboratory, and should be hit a salt fog on the baffle, the atomized droplets smashed into a fog or excess salt fog its back, make out the fog is really not containing water mist. The settlement of salt fog is directly related to the pressure of salt water supply and gas supply and the Angle of baffle.
5.2 air flow mist device can be subdivided into three forms, and the working principle is similar, but the nozzle Angle and the location of salt fog baffle installation are different. The refraction baffle is placed in front of the salt spray nozzle. Different from the reflection type, it is oriented towards the test space. It takes advantage of the baffle's lifting Angle to lift the object-shaped airflow to the top of the salt spray test box and then free subsidence (industry name: baffle spray). This laboratory USES Japanese patent non - crystallization spray nozzle structure, and baffle atomization. According to our experience, some parts of the baffle will not be atomized after atomization, but flow down, which will cause waste of salt water resources. Therefore, a collection device can be added to collect the salt water flowing down, so as to make greater use of salt water resources.
6. Drainage and pressure balancing system:
During the spray process, most of the salt solution will fall into the chamber except for the part taken away by the mist exhaust system. But after exceeding a certain height must discharge the chamber body in time. The discharge pipe and the discharge pipe can be combined organically, through a passageway both discharge salt fog and discharge water, and at the same time maintain pressure balance, the discharge port should be far from the test room. In order to meet the requirements of environmental protection, the salt fog discharged should be treated by the air purification tower.
7. Rapid mist discharge device:
After the test, there was a large amount of salt mist in the chamber, which could not be completely settled or discharged out of the room for a short time. In order to facilitate the test personnel to enter the chamber as soon as possible, this room is designed with a rapid mist exhaust device, which can remove the indoor salt fog within 30 minutes.
8. Electrical control system:
8.1 touch screen operation control system
Special programmable controller for 7-inch LCD touch screen;
(1) two control modes (constant value/program);
(2) sensor type: PT100 sensor;
(3) output mode: PID control output; (4-20ma) analog output;
8 switch signal auxiliary input; (basic configuration of 10 relays)
ON/OFF relay output;
(4) humidity measurement range: 1.0%--100%RH, error + / - 1%RH;
(5) program editing: it can be programmed into 120 groups of programs, each group of programs can be compiled into up to 100 sections, and loop operation can be set;
(6) communication interface :(RS232/RS485, the longest communication distance is 1.2km[fiber can reach 30km])
(7) interface language type: Chinese/English
Control object: chamber temperature, saturator temperature, salt water temperature, spray switch
A.Chamber temperature: test temperature, using corrosion resistant silicon rubber sheet heater, corrosion resistance is also better than other materials made of electric heat pipe. Its thermal inertia small, hot insulation resistance under high temperature can reach more than 100 m Ω, and long service life.
B. Saturation temperature: in order to ensure that the saturated air entering the chamber has a certain humidity and temperature, the compressed air should be heated and humidified. The saturator is not only a device for heating and humidifying the air, but also a device for purifying the air again.
C. Saltwater temperature: the saltwater temperature to be guaranteed in order to prevent the saltwater entering the test room from decreasing the temperature of the test room after being sprayed by the nozzle
D. Spray switch: switch between spray and stop according to different test procedures.
Implementation
F. Chamber temperature: this equipment adopts air heating chamber temperature, which is fed back to the control system through the temperature sensor, and the control system determines the output power through PID calculation to guarantee the chamber temperature, which has a stable and safe effect.
The heating adopts the heating system on the left and right sides of the chamber body
The temperature of saturator is transmitted to the control system through the temperature sensor, and the control system calculates the power through PID regulation to guarantee the temperature of saturator.
In spray, compressed air enters the nozzle and discharges salt water to form fog particles. The solenoid valve opens to spray. When the spray stops, the solenoid valve closes and the compressed air no longer enters the nozzle.
Safety protection system
1. Overtemperature protection
2. Water shortage alarm
3. Power failure alarm
4. Room door closed status display
Test Standards
GB/T 2423.18-2000, GB/T 6461-2002, GB/T 12967.3-91 CASS, GB/T 5170.8-2008, GB/T 5170.11-2008
GJB 150.11A-2008, GB/T 2423.17-2008, GB/T 10587-2006, GB/T 6461-2002, QB/T 3828-1999
ASTM.B117-2009, JIS H8502, IEC 60068-2-11-1981, IEC 68-2-52 1996, ISO 9227-2006
CNS 8886-2002, CNS 4159, CNS 4158
Key Parameters
Applications
Walk in salt spray chamber widely used in the aerospace industry, automobile electronics, electronic electrician, mobile phone digital, plastic products, metal materials industries.
