Process heating is an intricate part of the oil industry as it is important to keep petroleum products at the proper viscosity. This is especially important in oil pipelines. For example, crude oil may need to be pumped for a long distance and heating is essential. Yet, the right amount of heat is necessary as not enough can cause oil to be too thick and too much may actually damage it. As a result, the oil industry is turning to solutions provided by circulation and immersion heat systems. These systems not only produce enough heat, but offer exact temperature control for best results.
New oil wells produce quality crude oil but in time, they may bring up a great deal of water with the oil. This produces a need for effective water separation. Not long ago, fuel fired burners provided adequate heat but this method comes with some drawbacks. In fact, many companies are utilizing electric heat from immersion heaters because of the many benefits it provides.
Immersion heating is one of the most efficient ways to heat liquid for improving viscosity. Instead of heating with fuel (which can produce uneven heat) electric heating elements can be placed directly into the liquid for a more uniform and even heating process. Immersion heat can be either direct or indirect.
Direct heating is a method which employs heating elements actually submerged in the liquid they are heating. This is an excellent way to provide constant and uniform heat. As the element heats up it transfers all of its heat to the liquid so there is no heat loss taking place. However, some types of liquids can be corrosive, so it is sometimes necessary to use an indirect heating method.
Suppose you do not want your heating elements to actually come in contact with the liquid. However, you still want the same benefits of an immersion heating system. You can utilize an indirect system which contains a heating element inside of a pipe. This is commonly called “dry well” heat. In this way, the pipe and not the heating element is submerged in the oil. Heat can then take place from convection, conduction, and radiation, and the heating element stays protected the entire time.
Changing over will require some modifications. However, because electric heat is more efficient and is an eco friendly option, many companies are making the change. In fact, some companies are retro-fitting with flange type immersion heaters. This can be done by taking out the fire tubing and replacing it with the right size flange heaters.
When installing electric heat, you can use either direct or dry well type flange heaters. This will depend on your needs and applications.
Since electric heat is so much more efficient than gas, it is important to remember you will need far fewer BTUs of heat for your new heaters. For example, if you are replacing a 40 kilowatt burner, you may need to use a 20 kilowatt or even a 16 kilowatt electric heater. If you have the efficiency information, you can better determine if half the heat or one third is required for your application.
It is also important to consider the makeup of the oil you are using. For example, approximately how much and what kind of water does it contain? You may need to have an engineer conduct a field trial to get the best results and highest efficiency from your new heat system.
When choosing electric heaters, the selection of sheathes or casings are very important. For example, if you have salt water with your oil you will want a sheath which is resistant to salt corrosion. However, you should also check for sulfide compounds because this means you need something which is highly resistant to corrosion like a special nickel alloy. Also, when dealing with corrosive environments it is almost always better to go with dry well heating units as opposed to direct immersion heaters. Here are three important factors to keep in mind when changing to electricity:
In some cases, circulation heaters are the preferred types of electric heat. You can use either direct or indirect circulation heat.
A direct circulation heat system heats the oil and returns it to the tank. This helps to maintain an even and efficient method for heating oil. Oil is moved by a pump and this can be used to preheat or heat liquids.
Here is an example of an indirect circulation heat system. Suppose you have a large tank of crude oil. You need a way to keep it a constant temperature so it can be pumped through a pipe system, so water and other liquids can be separated. If you were to use direct immersion heat, your elements would soon become corroded from water and other materials so you choose an indirect circulation heater.
An indirect circulation heater is located outside of the tank. It heats liquid which is then pumped around or inside the tank in a special jacket or coiled tubing. This heated liquid warms the tank and the oil inside of it. Because the liquid is continually heated and circulated, only warm liquid comes in contact with the tank, to maintain an efficient heat system.
Before you make the change from gas to electric, make sure to choose a provider with years of experience and someone who can help you make the right decisions for your company. A trusted provider can help you make these important assessments: