How To Choose The Right Stainless Steel Tank For Your Application: Part 2 – Heating & Cooling
Stainless Steel Tanks
One of the most common questions we get at Zwirner Equipment is “which tank do I need?” In Part 1 of this series, we discussed the importance of shape and space when choosing the right tank for your application. Shape and space are just the beginning to choosing the right stainless steel tank. In this blog post, we will discuss how to determine the right tank for your application based on your heating and cooling needs.
Heating exchange surfaces come in three forms; steam, hot water or an internal heating element. When choosing the right tank, you have to make sure you have an appropriate PSI rating to achieve the desired result (for jacketed tanks only). To begin, there are two questions to ask: 1. How much surface area do you need to heat? 2. How quickly do you need the product heated? Direct steam is much hotter than water but not all jackets are rated to handle the pressure of steam. You can also inject steam in to hot water. Hot water, however, can only get to a temperature below 212°F before it transforms to steam. Therefore, if your product needs to be above 212°F, direct steam or injected steam is your best surface choice. Internal coils (also known as an internal heating element) are great for products outside of sanitary industries such as rubber. This is because the actual coil comes in contact with the product to heat it, making it harder to clean and creating a risk of burn on. It is cheaper to install because it does not require a jacket, but harder to maintain temperatures. Most used stainless steel tanks can be modified to use the heating exchange surface of your choice.
A cold wall tank has a cooling media that runs between the walls of the tank to cool the product. When choosing the right stainless steel tank, you have to make sure you have enough cold wall to achieve the desired result. Similar to heating, there are two questions to ask: 1. How much surface area do you need to cool? 2. How quickly do you need the product cooled? Once these requirements are established, you then will need to choose a type of cooling media. There are three cooling medias to choose from including Freon, Glycol (chilled water), and Ammonia. If you are shopping for a used stainless steel tank, you will have to take into consideration what type of media was previously used on the jacket. Below are the following recommendations from Zwirner Equipment about switching medias in a jacket:
If a used tank was previously using Freon, we do not recommend switching medias. Freon requires special copper piping and switching could be costly and risky.
If a used tank was previously using Glycol, we do not recommend switching to ammonia. Glycol leaves hard water deposits in the walls of the jacket and switching could cause deposits to flush into the ammonia compressor, ruining the compressor.
If a used tank was previously using Ammonia, we can switch the media to Glycol.
For more information about switching cooling medias or a tank that can both heat and cool your product, give us a call at 615.680.3312.
Heating and cooling are big factors in selecting the right stainless steel tank for your application. Once you have determined the space and shape requirements of your tank, you will then decide if you need any heating or cooling components. From there, you will evaluate your heating and/or cooling medias. Almost all products that require heating and/or cooling also require agitation. Are you wondering if you need agitation? Well if so, stayed tuned in for Part 3 of our series where we will discuss how to choose the right tank for your application based on your agitation needs