What is Steam Hammer & How to Eliminate Steam Hammer
If your heating equipment is violently shaking, then it is a concern that needs to be addressed. It is not only dangerous, but it also can be an expensive maintenance problem. Externally modulated technologies such as heat exchangers or unsophisticated forms of direct steam injection, such as spargers, can cause steam hammer. For more information on external vs. internal modulation, direct and indirect heating, and the spectrum of direct steam injection products, click here.
Why is Steam Hammer Happening?
There are multiple reasons why this cavitation issue could be occurring. Below are a few common scenarios.
- Uncondensed steam causes bubbles to form and collapse on tank walls, causing hammer and damage to the tank and peripheral piping.
- Check if you have an externally modulated steam pressure valve. This type of operation can lead to steam hammer or unit vibration as the steam mixes with the process fluid in the piping or tank. Over time, this can contribute to equipment wear, piping damage and lead to poor performance. If you have an externally modulated valve, consider purchasing an internally modulated option, which eliminates the problems associated with hammer and vibration.
- Monitor flow changes. Ideally, they should be gradual, and the temperature control loop should be able to respond to these changes. Review the initial sizing conditions provided to the equipment manufacturer. If production has increased or processing conditions have changed, the equipment may no longer be properly sized. Updated equipment or new components may be needed to compensate for these variations.
- Check your steam line for condensate. If there is excessive condensate in the steam line, then hammering and vibration could occur. If needed, purge the steam line. Depending on the piece of equipment, a drip leg and condensate trap may be recommended. Check with the equipment manufacturer for their specific recommendations.
Why is Cavitation a Concern?
- Inconsistent steam mixing and heat transfer leads to product inconsistency and wasted energy.
- Imprecise temperature control from steam hammering translates to higher energy costs.
- Tanks walls can be damaged, leading to maintenance headaches from welding over the damaged sections of the tank. Damaged tank walls can also be a major safety concern if hot water and hot steam would shoot out of the sides of a tank.
- Steam hammer can lead to a process equipment failure if the problem is severe enough. Not to be mistaken for water hammer that occurs in piping systems that utilize quick closing valves or that do not have a proper attenuation system, steam hammer is a result of uncondensed steam instantaneously cavitating on the tank wall or piping with damaging force.
How can you Prevent Equipment Vibration?
Hydro-Thermal’s patented direct steam injection heaters and skid systems are designed to eliminate steam hammer and vibration, among other benefits. Hydro-Thermal’s internally modulated Jetcooker™ utilizes a single nozzle which focuses the incoming steam and accelerates it to a very high velocity (usually sonic velocity) before it comes into contact with the process fluid. This high velocity helps to atomize the steam bubbles and shear the incoming process fluid, which allows for a more complete, efficient heat transfer. The result is no steam hammer, precise/uniform heating, and reduced maintenance.
Contact us today to get a free evaluation from our application experts. They can provide tips on how to optimize your heating and eliminate steam hammer.