Heating of tanks
Tanks with a liquid product are stored on many industrial and technological facilities. Maintaining temperature of the liquid environment can be crucial if it is about foodstuff, oil branch and some other productions. In cold season it is impossible without heating. One of the simplest options allowing to support the necessary conditions in tanks is cable heating of tanks. The heating cable is properly isolated electrical wire, it is put in a special way in a vessel or is mounted on its surface. Control elements allow to maintain temperature in the required range automatically.
Application for free calculation
Tanks heating system: purpose and elements
At non-compliance with temperature condition of the liquid environment such consequences as crystallization, freezing, hardening are possible. In the food industry the product spoils and becomes unsuitable to the use.
What is included into the heating system?
For creation of a heating system the following components are used::
- control cabinet;
- devices of protective shutdown;
- temperature regulator with the sensor;
- fastening and connecting elements;
- power and control cables.
The tank warmed by a cable can be stored in the open air and indoors. No matter how viscous is the stored liquid, by means of such system it is possible to support its characteristics. It is covered with isolation from inactive substance, for example, fluoropolymer or polyolefin, so that hostile chemical environment didn't react with material of the wire. Such approach allows to warm tanks with chemically, explosion-and combustible environment.
Why should tanks be heated?
By means of a heating system of tanks it is possible to solve several problems at once:
- maintenance of environment temperature demanded for storage;
- heating of liquid to the necessary parameters to use it for technological processes;
- avoidance of change of consistence and emergence of condensate;
- anti-frosting of the tank. It is especially important for the containers with water in the open air.
As a rule, for heating the self-regulating cable is used, but in some cases, if the task is simple, resistive one can be also used. Sometimes instead of a wire special girds are used. Upgrade of system with panels, which have bigger area, is possible: in some cases it will increase efficiency.
Thermal isolation is a necessary element of system, it shouldn't be confused with chemical isolation. In case of absence there is a risk that there won't be enough cable power in difficult situations (a considerable cold snap). An additional pro argument is: the lack of the isolating material leads to additional electric power expenses.
Design and calculation
To create an effective heating system, it is necessary to follow several rules.
1. To provide weather conditions on the area (range, within which air temperature varies).
2. To take into account properties of the tank (volume, dimensions, material of walls, existence and type of isolation, position).
3. To consider properties of a product (viscosity, hardening temperature, range of temperatures of storage).
Using these parameters, it is possible to calculate and design steadily working system. You can learn more about calculation of a cable for heating of tanks in this article.
Installation of a cable heating system
The most widespread way is winding the tank with the heating cable. It is the most universal for any environment and simple way of installation. For fastening of a cable on the case of a vessel several methods are used:
Brackets or probes are attached to the tank by welding and then mounting tape for the cable is attached to them.
Usage of clips means that the whole tank is surrounded with them incrementally. The mounting tape is attached to this clips. We will apply this way to tanks of small diameter or to a pipe.
If it is decided to fix a cable by means of a grid, then it is pulled on all surface. After that, as well as in the previous cases, the cable is fixed with tape. This method allows to distribute the warming elements on all surface of tank, that is especially effective if it is filled up to the top.
After the cable is fixed, the heat-insulating material and casing for its protection against moisture are mounted.
Recommendations of professionals
Our experts from the Moscow office have long-term experience of design and installation of constructions. As well as in any technological process, at development of the system of heating of tanks it is also necessary to make use of practical experience. It allows to find more effective solutions for uncommon tasks. Several recommendations from skilled assemblers:
- when fixing a cable on the lower part of tank it is necessary to put it on a serpentine trajectory;
- if cable segments are used, then it is possible to fasten them among themselves with mounting tape;
- it is always better to mount a casing, so that the made foam thermal insulation didn't become wet and didn't lose the properties.
Selection of a cable
When choosing a cable, the self-regulating product with power from 16 to 40 W/m is usually used. The specific choice depends on object parameters. As an example, it is possible to consider properties of the heating TSL and TSA cables.
There are two cover options for both types of cable - from polyolefin (are suitable for weak inorganic environments) and fluoropolymer (are optimum for organic corrosion liquids).
The thermal mode is a very important parameter for storage of some products. Having set cable heating of tanks, it is possible just to solve this problem so that tracking and maintenance of working temperature was carried out in the automatic mode.