I would like to ask what are the common types of bottom valves for reaction vessels?
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When searching online, I came across many different types of valves, such as upward-opening discharge valves and angle valves. I would like to know what types of bottom valves are commonly used in reaction vessels, as well as the advantages and disadvantages of each type. In my company, I’ve only seen ball valves; when clogging occurs, nitrogen backflow is usually used to resolve the issue. I’ve never seen upward-opening discharge valves used
For materials prone to clogging, an upward-opening type can be preferred
Will the resistance to movement be high, and what is the level of sealing? Is it resistant to corrosion?
To resolve this problem fundamentally, the process must be changed to prevent material precipitation. Alternatively, increase the stirring speed during material addition to prevent sedimentation; I use a downward stirring method, and the speed of material addition is much higher than that of the reaction.
Generally, there are upper expansion valves, lower expansion valves, ball valves, etc., and cut-off valves are used for emergency material discharge.
Upward and downward opening types, or ordinary valves
The upper discharge valve is not difficult to get clogged with material; rather, it makes it hard for the material to agglomerate during the crystallization process. There are basically two reasons for the blockage of the ball valve bottom valve: blockage before discharge, and blockage during discharge. The blockage before discharge is usually caused by solids accumulating in a solidified mass in the dead zone ahead of the ball valve; moreover, although nitrogen is used for backwashing, it can only create a temporary passage, and once the nitrogen supply is stopped, the accumulation settles and collapses, preventing discharge. This upward-flow valve can solve the problem, as its flow channel is completely isolated from the system before the valve is opened, and there is no dead zone. Another situation is that the slurry or lumps dispersed within the tank gather as material is discharged; eventually, no more material can be discharged, and even the upward discharge valve cannot help in this case. After the upper control valve is opened, its size is sometimes even smaller than that of a ball valve; the smallest cross-sectional dimension I have here is only 14 mm, and blockage still occurs. Another feature of the upper discharge valve is that it is difficult to clean after discharging material. Outside the reactor system, there will be some dead zone at the upper expansion valve. These dead zones tend to accumulate solid matter and are difficult to remove. In many cases, we disassemble and clean it.
I’ve learned something new. Here, we work with active pharmaceutical ingredients, and the reaction vessels need to be cleaned frequently. This is probably why that top-loading design wasn’t used. The problem of blockages isn’t too serious; we haven’t encountered any blockages during the material transfer process yet
We commonly use ordinary ball valves and angle valves
Keep in mind that using an upper conveyor isn’t a panacea either; materials that tend to get clogged can still get stuck if not handled carefully. It also needs to be used in conjunction with agitator blades. It really depends on the material; ball valves, after being in use for a certain period of time, end up in a state of stillness
It is recommended to use upward-opening bottom valves and tank bottom valves; a jacket as well as cleaning holes can be provided； The fully forged bottom valve from German company Ritag is worth considering; for more information, please contact 379662240@qq.com