Electric Heat Tracing Cable Manufacturer
In China, most process pipelines and tank containers use traditional steam or hot water heat tracing. Electric heat tracing uses electrical energy to supplement the heat lost by the traced object in the process, thereby maintaining the most reasonable process temperature of the flowing medium. It is a high-tech product. Electric heat tracing provides uniform heat release along the length of the pipeline or over a large area of the tank volume, unlike electric heating which concentrates heat load at a point or small area. Electric heat tracing has a small temperature gradient and long thermal stability time, making it suitable for long-term use. The required heat (electric power) is much lower than that of electric heating. Electric heat tracing has advantages such as high thermal efficiency, energy saving, simple design, easy installation, no pollution, long service life, and remote and automatic control. It is the technological development direction to replace steam and hot water heat tracing and is a nationally promoted energy-saving project.
Solution
Electric heat tracing, as an effective pipeline insulation and anti-freezing solution, has been widely used. Its working principle is to dissipate a certain amount of heat through the heat tracing medium, compensating for the heat loss of the traced pipeline through direct or indirect heat exchange, to achieve normal working requirements for heating, insulation, or anti-freezing.Advantages
Electric heat tracing compared to steam (hot water) has many advantages as follows:(1) Electric heat tracing has simple devices, uniform heating, accurate temperature control, remote control, remote control, and automated management.
(2) Heat tracing has explosion-proof, all-weather performance, high reliability, and long service life.
(3) Electric heat tracing has no leakage, which is beneficial to environmental protection.
(4) Saves steel: It does not require the two-way heat tracing pipelines needed for steam heat tracing.
(5) Saves insulation materials.
(6) Saves water resources, unlike boilers that require large amounts of water daily.
(7) Electric heat tracing can also solve problems that are difficult to solve with steam and hot water heat tracing.
(8) Electric heat tracing has low design workload, convenient and simple construction, and low maintenance workload.
(9) High efficiency, can significantly reduce energy consumption.
Whether it is one-time investment or annual operating cost, electric heat tracing cables are more economical than steam heat tracing; for some projects, the one-time investment of electric heat tracing cables may be slightly higher than steam or hot water heat tracing, but in terms of annual operating cost, the savings from electric heat tracing operation in 1-2 years can recover the investment.
When the electric heat tracing cable is connected to the power supply (note that the end core wires should not be connected), current flows from one core wire through the conductive PTC material to the other core wire, forming a circuit. The electric energy heats the conductive material, and its resistance increases accordingly. When the temperature of the core belt rises to a certain value, the resistance becomes so large that it almost blocks the current, and the temperature no longer rises. At the same time, the electric heat tracing cable transfers heat to the lower-temperature heated system. The power of the electric heat tracing cable is mainly controlled by the heat transfer process, automatically adjusting the output power according to the temperature of the heated system, while traditional constant power heaters do not have this function.
Classification
Common electric heat tracing can be divided into the following types for different pipelines (tanks):
Self-regulating
This heat tracing cable has resistance that increases and power that decreases as temperature rises. Due to its large starting current, the length used generally does not exceed 100 meters. The heat tracing cable can be cut arbitrarily, and no matter how long, it can generate heat when connected to the rated voltage.
Parallel
This heat tracing cable uses two (or three) parallel insulated copper stranded wires as power busbars, with PTC characteristic heating wires wound around a skeleton. At each heating section length, the heating wires are alternately connected to the busbars, forming a continuous parallel resistance. The length of this heat tracing cable is about 10-800 meters.
Series
This heat tracing cable uses three parallel insulated copper stranded wires of the same cross-sectional area and a certain length as power busbars and heating core wires. One end is reliably short-circuited, and the other end is connected to a 380V (or designed voltage) power supply, forming a star load. According to Joule-Lenz law: Q=0.24IRT, electrical energy is converted into thermal energy, and the star load continuously releases heat, forming a continuous, uniformly heating electric heat tracing cable. According to actual needs, the three-phase (single-phase) of the heat tracing cable can be separated (split type) or integrated. The length of this heat tracing cable should not be too short, generally about 500-2500 meters.High Temperature Electric
This heat tracing cable is made of fiberglass or other high-temperature resistant materials, with a temperature resistance of up to 300°C, and lengths ranging from 1 to 50 meters.Silicone Rubber Electric
This heating cable can be used for heating, heat tracing, and insulation of industrial equipment or laboratory pipe boxes, tanks, and troughs in humid, non-explosive gas environments, oil drums (tanks), with lengths of 1-15 meters.MI Heating Cable
This heating cable consists of a metal core (heating element), tightly surrounded by mineral magnesium oxide (insulation layer) around the core, and a metal tube (usually copper, steel, or stainless steel) that has been drawn multiple times. The continuous working temperature can reach 250-590°C, and the short-term working temperature can reach 1083°C, with lengths of 18-680 meters.
Design Process
Design Drawing
Before construction, a complete design drawing should be prepared, which should include the following information:Line number: indicated by a rectangle at the power supply point;
Heat tracing cable required for the line, length, and model;
Length of heat tracing cable required per meter of pipeline, with a number greater than the former indicating spiral winding;
Length of heat tracing cable required for each valve;
Remarks;
List of supporting materials and accessories for the heat tracing system;
List of accessories for the temperature control system;
List of materials required for construction;
Design parameters considered and specifications of insulation materials used.
Preparation
(A) Pipeline system:1. The pipeline system and fittings have been constructed;
2. The anti-rust and anti-corrosion coating is dry;
3. The pipeline system construction and specifications are consistent with the design drawing;
4. Remove all burrs and sharp edges.
(B) Heat tracing cable and accessories:
1. Check if the surface of the heat tracing cable is damaged;
2. The insulation performance of the heat tracing cable is good (insulation resistance should be 20 megohms when tested with a megger at 1000VDC);
3. The models of the heat tracing cable and all accessories match the design requirements.
(C) Site preparation
Place a roll of heat tracing cable and the reel on a bracket near one end of the line.
Lay the heat tracing cable along the pipeline and avoid the following:
* Placing the heat tracing cable on burrs and sharp edges;
* Pulling the heat tracing cable forcefully;
* Stepping on or placing heavy objects on the heating cable.
Single Installation Method
1. Use fiberglass heating tape (high-temperature resistant heating tape) to fix the heating tape to the pipeline at intervals of about 50 cm;2. Attach the heat tracing cable to the lower half of the pipeline as much as possible;
3. Reserve 50 cm of heat tracing cable at each power supply point and end of the line;
4. Lay the cable according to the "winding coefficient" shown in the design drawing;
5. For all heat dissipating bodies (such as brackets, valves, flanges, etc.), reserve the required length of heat tracing cable according to the design drawing, and wind this section of heat tracing cable around the heat dissipating body and fix it. The following points should be noted:
* The heat dissipating body should have the required length of heat tracing cable as per design;
* Heat tracing cables can overlap each other;
* The winding method should allow the heat dissipating body to be removed for maintenance or replacement without damaging the heat tracing cable or affecting other lines;
* At two-way or three-way fittings, reserve 40 cm of heat tracing cable at each end.
Spiral Winding
For example, if the winding coefficient is 1.4, it means that 5 meters of pipeline requires 7 meters of heat tracing cable. During construction, first fix both ends of a 7-meter section of heat tracing cable to a 5-meter pipeline, then wind the loose heat tracing cable around the pipeline and fix it.
