How to properly operate the electric blast drying oven to avoid the risk of explosion? -Huaqiang Electronic Network

A few unfamiliar users are operating

Electric blast drying oven

I am worried that the equipment will explode and my personal safety is not guaranteed. Therefore, during the operation, I will be afraid of it;

How to properly operate the electric blast drying oven to avoid the risk of explosion?

Their practices can be roughly summarized as

4

Article. These experiences only provide a warm reference, I hope to help everyone, thank you

!

Let us first understand

Electric blast drying oven

Will there be an explosion?

?

Dongguan Haotian is your authoritative professional answer: Although the various types of drying ovens in daily life are non-explosion-proof products, they do not use any materials and components that can cause self-explosion after heat. However, a small number of users did explode when they used it. What is the reason for this?

?

Here we need to start with the two necessary conditions that caused the explosion.

1

There must be a flammable, explosive and volatile object that can cause an explosion. This is an internal cause.

2

It is necessary to have suitable concentration, flash point temperature and pressure conditions, which is an essential external factor.

If the working room is not filled with flammable, explosive and volatile objects, the drying oven will not be able to explode. If a flammable, explosive, and volatile object is placed in the work chamber, but the concentration of the volatilized gas does not reach the concentration necessary for the explosion, no explosion will occur. If the concentration is reached, the flash point temperature that can cause the explosion is not available, and no explosion will occur. If both the concentration and the flash point temperature are available, it can only cause combustion and cannot form an explosion because it is in an open container.

Therefore, in the case of a drying oven where an explosion occurs, the user must inevitably put in a flammable, explosive and volatile object.

(

Workpiece

)

For example, motor rotors, stators, transformers, etc., which are immersed in varnish. For example, a varnish containing an appropriate amount of an organic solvent such as mixed xylene. These organic solvents evaporate and the varnish dries. The purpose of drying the rotor, stator, etc. of the varnished motor in a dry box is to accelerate the volatilization rate of these organic solvents. Xylene

[C6H4(CH3)2]

Gas in

450

°C

Under the following environmental conditions, you will not burn if you do not encounter an open flame. Even though the temperature of the studio is only

100

°C

Left and right, however, the surface temperature of the oven heater has far exceeded

450

°C

. The mixed xylene gas is brought to the surface of the heater by the circulating air, which inevitably causes spontaneous combustion or flash fire. If the concentration of mixed xylene gas in the studio exceeds this time

1.1% (

Volume percentage

)

, it will immediately cause a large area of ​​burning by flash fire. It is well known that the combustion of a gas causes a sudden expansion of the volume, and when the tank cannot withstand the pressure generated by the rapid expansion, the explosion inevitably occurs.

So how to avoid the danger of explosion of electric blast drying oven?

?

The following is the problem of our company

(

Dongguan Haotian Testing Equipment Co., Ltd.

)

Many years of production engineers answer your professional authority: I hope to help you.

;

1.

The varnish is thoroughly drained, and it is absolutely impossible to put the still-painted workpiece into the work chamber for drying.

The workpiece cannot be placed on the bottom plate of the studio. The workpiece in the studio cannot be filled. The air duct must be left between the workpieces. The air intake and exhaust device of the equipment should be installed according to the instructions.

2.

The chamber is preheated to a drying temperature and enters a constant temperature phase, and the blower is always kept in operation. Open the door and turn off the workpiece after turning off the heater power

Put it into the studio and use the waste heat to volatilize most of the mixed xylene gas. The heater must never be heated during the preheating process.

3.

These gases are pumped directly out of the room during the preheating process using a suction line for half an hour. Or open the door after half an hour to release the volatilized mixed xylene gas.

4.

The heater is powered and the temperature rise process of the temperature control instrument is monitored until the temperature specified by the process is stabilized.

special reminder:

(1)

The enterprise shall formulate scientific and reasonable operating procedures, stipulate the steps of starting and heating the equipment, as well as the status, quantity and assembly of the workpiece.

Methods. Employees should operate in strict accordance with the operating procedures. Pay special attention to the possibility that employees will violate the operating procedures during the fatigue state.

(2)

For the drying of inflammable and explosive materials, the old equipment should be updated, and the safety door should be used as much as possible.

105

,

106

Products are relatively safer devices.

In short, any equipment must be extra careful when it comes into contact with flammable, explosive, and volatile objects. Accidents can only be avoided if they act in strict accordance with the laws of science.

Tips

:

The following may be helpful to you:

There are commonalities in the appearance characteristics of the drying oven.

?

The engineer authority answers your questions professionally:

In the event of an explosion

90%

Occurs in the process of drying electrical components after dipping.

Place the workpiece with a large amount of liquid diluent directly into the working chamber and warm it up at full speed.

Most of the time when the drying oven explodes occurs in the autumn and winter. Usually after lunch and after work. Generally closed the door

20

Minutes or so.

There is a drop of paint on the bottom of the drying oven studio where the explosion occurred.

(

Except for direct drying thinner

)

.

Some users stuffed the workpiece in the drying chamber studio, resulting in poor air circulation and air clogging in the drying chamber.

Some users' drying boxes have not installed the air-exhausting and exhausting devices according to the instructions. The safety doors have not been checked for flexibility for a long time.

There are basically no trained operators or operators who have received no prior training.

There are no specific safety procedures and no records of duty or operation.