Calculation of the drainage volume of the steam heater outlet condensate pipe drain valve

Let me pour some cold water on the OP. In my experience, using a steam trap as a valve for draining condensate from a steam heater is not appropriate; both the steam supply and condensate drainage to the heater must be continuous and stable for it to function properly. A steam trap discharges liquid intermittently; when it closes, it can cause pressure buildup in the steam, and in severe cases, this can lead to system oscillations and overpressure. Most likely, the ultimate solution will be to avoid using a steam trap and instead open the bypass drain valve directly, resulting in liquid discharge along with steam and thus waste of steam. Installing it directly on the condensate pipe does not guarantee that all the condensate will be collected; it is more reasonable to place a condensate collection tank at a lower position. Recommendation: Install a condensate collection tank equipped with level control. After setting the desired liquid level, use a PID control valve to regulate the drainage opening, thereby ensuring the continuous and stable operation of the system. Just boasting – the original poster can try following your approach first, and come back for adjustments if it doesn’t work. :Lol, be careful (make sure to install a bypass valve in a safe location on the steam trap)

When calculating the drainage volume of a steam trap, simply estimating it as twice the steam consumption may not be accurate enough. The calculation of discharge volume must take into account various factors, including the amount of condensate produced after steam compression, the operating pressure and temperature of the steam system, the quality of the steam (dryness), as well as any flashing that may occur within the pipes. First, you need to check the actual operating conditions of the steam, especially its dryness degree, as a low dryness degree of the steam (i.e., it containing more moisture) leads to the generation of more condensate water. Secondly, it is necessary to refer to the specific manufacturing parameters and performance curves of the steam trap, which are usually available from the manufacturer. The selection and design of steam traps usually require consideration of parameters such as the maximum operating pressure, maximum processing capacity (kg/h), and differential pressure. It should also be noted that although it is necessary to take safety factors into account, the choice of these factors should be adjusted according to specific operating conditions; generally, a safety factor of 1.5 to 2 times is considered a common practice. However, in some cases, it may be necessary to adjust this coefficient based on the dynamic changes in the steam system. It is recommended to consult a professional steam system engineer or trap supplier to obtain more accurate calculation and selection advice. At the same time, it is also advisable to use relevant software for simulation calculations to verify the correctness of the manual calculation results. .

Thank you for your friend’s suggestion. Initially, the design was carried out according to your suggestion – a tank was added at the condensate outlet, which was controlled via a control valve. Later, expert review led to the change to installing a hydrophobic valve. Therefore, I also have no idea what the pros and cons of using a steam trap are.

Since there is steam consumption, the theoretical drainage rate is 1000 kg/h. Indeed, as mentioned above, there are many factors to consider in practice, but since the safety factor has been doubled, there should be no problem; external factors have less of an impact on the drainage rate

Upon receiving feedback from the owner, it was found that when heating the storage tank, the trap installed at the heater outlet caused vibrations and noise. However, after removing the trap and installing it directly, such problems no longer occurred. The suggestions given are actually quite good, but I have a question: regarding the heating of the storage tanks in the tank farm, should there be one heater and one condensate tank, or should multiple heaters be used? ； Secondly, from a design perspective, it’s awkward in that not all property owners face this issue. But if you add a tank, factors such as the characteristics of that tank and the required safety distances introduce many design challenges. This is probably why, as mentioned by the original poster, experts recommend installing a steam trap.

What users care about is security and stability; efficiency comes second. The steam heater used is for the concentration of waste acid, and any shaking of the system could damage the graphite blocks inside it. The saturated steam pressure rating was reduced during design to circumvent certain regulations regarding pressure vessels. Each system is equipped with its own condensate collection tank; if they are shared, there is a high risk of steam crossover occurring when one system is shut down for maintenance ； During parallel operation, the steam inlet pressure varies due to different operating conditions. If a hydrophobicity issue occurs, it is difficult to determine which system is having the problem. As for whether the storage tank heaters can share a single collection tank, it depends on the operating conditions in the upstream section; if pressure has little impact on heating and poses no effect on production or maintenance, I think it is feasible.