Welcome to Shanghai! Our main products: magnetic shutter level gauge, ultrasonic and magnetic level gauge
Address:No. 107 Nanshan Road, Shanghai, Jingan District

ZWL series of self-controlled thermal cable

The hot cable, thermo-controlled electric companion tropical, also called the self-regulating electr…


The hot cable, thermo-controlled electric companion tropical, also called the self-regulating electric companion hot line or the self-limiting thermoelectric tropical. It is a kind of hot power with the temperature of the system and the temperature of the band. Electric tracing band itself has limit temperature automatically, and with the change of the temperature of the heated system can automatically adjust the function of the heating power, to ensure that the system is always stable in setting the best operating temperature range of normal operation.

1, work features: heating automatically limit working temperature of electric tracing band, can change with the temperature of the heated system automatically adjusts the output power without additional equipment, electric tracing band can be arbitrary cut short or long use within a certain range, and the performance is constant. Allow cross overlapping to be laid without overheating and burning.

2, work advantages: temperature control electric tracing band when used for freeze protection and insulation, has the following advantages: uniform temperature, heat tracing pipeline does not overheat, safe and reliable, save electricity, intermittent operation, heating up quick start, installation and operation cost is low, install and use, simple maintenance, easy automation management, no environmental pollution.

3, PTC working principle: PTC effect and PTC materials, PTC effect namely the positive temperature coefficient effect, is especially material increases as the temperature rises, the resistivity, and the characteristics of the resistivity increases sharply in a certain temperature range. The PTC materials are PTC materials, and the polymer PTC is a mixture of semi-crystal polymers and carbon black.

How to work: the thermoelectric component of the thermoelectric companion tropical is a core band made of a layer of PTC material that is evenly squeezed between two parallel metal bus lines. After the PTC materials were melted and cooled, the carbon particles were dispersed to form an endless network of tiny, electrically conductive carbon. When they cross two parallel bus lines, the PTC parallel circuits of the core band are formed. When the two bus lines on one end of the tropical end are connected to the power supply, the current flows across the PTC material from one bus to the other to form a parallel circuit. The PTC layer is the resistance heating body that is parallel between the bus, which converts electrical energy into heat and heat insulation to the operating system. When core temperature rises to the corresponding high resistance zone, the degree of resistance to almost breaking current, the temperature of the core zone to reach high limit no longer increases (i.e., automatic temperature limit). At the same time, the core is heated by a heated system that is heated to the lower temperature, and the amount of heat transferred by the unit time to the steady state time is equivalent to the power of the electric companion tropical. The output power of the electric companion tropical is controlled by the heat transfer process and the temperature of the heated system.

The power of electric companion tropical: the electric heat power of a power self-tuning electric companion tropical is automatically decreased with temperature, or automatically increases with temperature. 2 since the limit temperature electric tracing band electric heating temperature, the resistance increases, when the resistance with maximal electric power tend to be minimal, the temperature rose to high limit, this is the limit temperature of electric tracing band features. Heat limited by heat is the process by which the electric accompanying tropical heat can be carried out in a hot zone under the temperature limit. Electric tracing band 3 PTC memory performance of resistance increase with temperature increasing, when cool if resistance can along the route back to the original starting point, the original warming is with PTC memory performance. The memory performance of the electric companion tropical can be used over and over again.

The core band of the 4-temperature uniform thermo-controlled tropical zone is composed of PTC parallel units formed by a large number of thin conductive networks. When the heat and energy intensity of any section of the heat pipe occurs, the PTC elements in the area can be directly warmed and independently responded. Instant toward eliminating fluctuations automatically adjust their output power, the temperature is low power adjustable, high temperature power down, and the extent of temperature fluctuation according to size, given the size of the power amplitude modulation, in order to maintain the whole system of each section temperature uniformity and stable operation. This is a micro-area tracking, complete synchronization, fully automatic thermal insulation process.

Main parameter definition: nominal power

Refers to under the rated voltage, rated power to electric tracing band within a certain amount of thermal insulation layer of heat tracing pipe temperature is 10 ℃, the temperature control of electric tracing band output steady electric power per meter. Temperature control temperature control index refers to the temperature rise per 1 ℃, the falling value of the output power electric tracing band, or every 1 ℃ below the temperature, the added value of the output power of electric tracing band (generally lowest) is given. Maximum maintenance temperature

The maximum temperature that can be maintained by a certain type of electric companion tropical is called the maximum maintenance temperature of this type of electric companion tropical. The maintenance temperature is a relative parameter, which is related to the heat loss of the insulation system and is related to the highest surface temperature of the electric companion tropical. In the use of the right design, the system temperature can be maintained at any temperature from the highest temperature to the ambient temperature. The highest exposure temperature is the temperature of the external heat source applied to the tropical heat. After the exposure temperature is above a certain temperature, the electric heat properties of the electric companion tropical will begin to be damaged. The temperature is the highest temperature that the thermoelectric companion tropical can withstand, known as the highest exposure temperature. Maximum surface temperature

The maximum electric temperature that can be reached on the surface of a tropical surface that works under the rated voltage under favorable heat insulation conditions. This parameter is important for inflammable materials and explosive atmosphere. Maximum use length on the rated working voltage of a single power supply, the maximum length of the maximum length is allowed by the electric companion tropical. Maximum use length is related to rated voltage, power, specification and ambient temperature. If more than maximum use is required, the power supply should be connected.

Product type and structure: product type specification method

The models and specifications of the products are shown below: structural type, rated voltage, product code, temperature grade, nominal power from left to right

1) nominal power: for example, "10" means the nominal power is 10wm-1.

2) temperature: D for low temperature; Z, wen said.

3) product code: WL means thermo-controlled electric companion tropical.

4) rated voltage: 1 for 110V; "2", said the 220 v; "3", said the 380 v.

The structure type: "J" indicates the basic type, "P" means the shield type, "F" means protection.

Example: 10 dwk2 - F

The protective cold temperature thermo-controlled electric companion tropical (as shown in figure 1), nominal power 10wm-1, rated voltage 220V.

Product type specification

The product model is shown in table 1

Table 1 product type specification (220V)

The basic type shield type protection type nominal power W/m

Low temperature series DWL - J dwl-f - F 10, 25, 35, 45

Middle temperature series

4.3 product structure

(1) conductor (copper wire 1.0, 1.5, 2.5 mm2)

(2) the PTC core belt

(3) modified polyolefin insulation

(4) copper wire braided shielding layer

(5) modified polyolefin or fluorocarbon resin sheath

Key performance parameters

Low temperature series performance parameters

-- standard color: black

- temperature range: the maximum maintain temperature 65 ℃

The highest exposure temperature 85 ℃

The highest surface temperature of 85 ℃

- construction temperature: the minimum 60 ℃

- thermal stability: the loop back and forth between 10 ℃ to 99 ℃ after 300 time, electric tracing band calorific value remain above 90%.

- bending radius: 20 ℃ at room temperature for 25.4 mm, and 30 ℃ low temperature, to 35 mm.

- insulation resistance: electric tracing band length 100 m, the environment temperature of 75 ℃, the minimum value of insulation resistance of 20 m Ω.

5.2 DWL electric power with tropical power - temperature working curve (power 220Vac),

The temperature series performance parameters of 5.3

-- standard color: brown

- temperature range: the maximum maintain temperature 105 ℃

The highest exposure temperature 135 ℃

The highest surface temperature of 135 ℃

- construction temperature: the minimum - 30 ℃

- thermal stability: the loop back and forth between 10 ℃ to 149 ℃ after 300 time, electric tracing band calorific value remain above 90%

- bending radius: 20 ℃ at room temperature for 25.4 mm, and 30 ℃ low temperature of 35 mm.

- insulation resistance: electric tracing band length 100 M, the environment temperature of 75 ℃, the minimum value of insulation resistance of 20 M Ω.

ZWL battery is a tropical power - the temperature curve (power supply 220Vac), as shown in figure 2

The maximum use of the 5.5 fuse is shown in table 2

Table 2 fuse type and maximum use length

Electric tracing band specifications starting ℃ temperature fuse

10 a 20 a 30 a 40 a.

The maximum length (m) for a single power supply.

15 dwl2 - J + 10-20-100

25 dwl2 - J + 10-20-100

35 dwl2 - J + 10-20-100

40 zwl2 - J + 10-20-100

50 zwl2 - J + 10-20-100

60 zwl2 - J + 10-20-100

6 use

They need to be frozen, melt ice, melt snow and prevent condensation.

It is easy to liquefy, solidify, crystallize and viscous liquid pipe, valve, pump, container, tank, tank, reactor, etc. Heat insulation, viscosity and block. Such as gas, chlorine gas, crude oil, heavy oil, cooking oil and water pipes, especially when the above pipeline is not completely empty.

Measure the branch of the instrument because it is thinner and the material does not flow.

No need for precise thermostatic instrumentation, components, and low power temperature heat.

-- agricultural products processing and other USES, such as fermentation, incubation, breeding, etc.

Use caution

-- transport, storage, installation and use to avoid crushing, bumping, bending, and organic solvents or oil spills.

The connection with the tropical one is connected to the power supply, and the core of the other end must not be short-circuited or in contact with the conductive material, and must be sealed with a sealed head. In case of explosion explosion the explosion proof junction box should be used. The sheath shall not be damaged, and the core band shall not be bare.

The output power of the electric companion tropical is related to the many factors of the thermal system, and it is necessary to use the electric companion tropical to design the heat industry to achieve the best performance.

Simple thermal design

Electric heating is the use of electric tracing band output to compensate for the heat pipes, containers, tanks and so on the heat dissipation by the storage and transportation system, in order to maintain the system operating medium is always at the appropriate temperature range of technological requirements. Therefore, the heat loss of the process unit is determined by the heat loss of the process unit, and then the power and length of the electric companion tropical is determined according to the heat consumption.

The design requires certain process parameters

1) the maintenance temperature required by the pipe, TV;

2) local minimum temperature (℃), TA;

3) the diameter of the pipe, D;

4) the surface area of the container, S;

The variety and thickness of the insulation materials of the pipes;

6) the pipe is indoors or outdoors.

The calculation of tube and heat loss in plane

8.2.1 pipeline

Heat loss (+ 30% safety factor) of the insulation pipe is calculated by the formula (1) :

Qt = {[2 PI (TV - TA)] / [LnD0 / D1] 1 / lambda + 2 / (D0 alpha)} * 1.3... (1)

8.2.2 plane

Heat loss (+ 30% safety factor) of the insulation plane is calculated by the formula (2) :

QP = [TV - TA] / (delta/lambda + 1 / alpha)] * 1.3...... (2)

Type (1) and (2) :

Qt - the heat loss of the unit length pipe, W/m;

Qp - unit flat heat loss, W / ㎡;

TV - maintain temperature of the system requirements, ℃;

TA - local minimum ℃ ambient temperature;

Lambda - coefficient of thermal conductivity of insulation materials, W/(m ℃), as shown in table 3.

D1 -- the inner diameter of the insulation layer (pipe diameter).

D0 -- insulation, m; D0 = D1 + 2 delta;

Delta -- the thickness of the insulation layer, m;

Ln of natural log;

Alpha - coefficient of heat transfer for atmospheric insulation appearance, W/(㎡ ℃) and wind speed, omega (m/s),

Alpha is calculated by the formula (3) :

Alpha = 1.163 (6 + 1/2 omega) W/(㎡ ℃).............................. (3)

8.2.3 piping material correction factor

The thermal conductivity of different materials is different, the power difference under the same TV is different, the correction coefficient Kc is shown in table 4.

The condition of Q t and Q is steel, such as material variation should be multiplied by material correction factor. For example (4) :

The thermal conductivity of heat insulation materials is used in table 3

Heat preservation material coefficient of thermal conductivity W/(m. ℃)

Glass fiber 0.036

Mineral wool 0.038

Calcium silicate 0.054

Expanded perlite 0.054

Vermiculite is 0.084

Rock wool 0.043

Polyurethane 0.024

Polystyrene 0.031

Foam plastic 0.042

Stone cotton 0.093

Table 4 shading coefficient

Correction factor for piping materials

Carbon steel 1

Copper 0.9

Stainless steel 1.25

Plastic 1.5

Q = Qt * k W/m...... (4)

To calculate the total length L of the electric companion tropical

Use the Q value to select the appropriate type of electric companion tropical, and determine the length and the means of the installation for each meter pipe.

The 8.3.1 pipe is partially powered by the tropical Lg

1) each meter pipe shall be made of electric companion tropical length Lg:

Lg = Q/QM m/m......... (5)

In the form, QM is the output power (W/m) for a specific electric companion tropical in maintaining a temperature TV.

2) when Lg is less than 1, the electric companion tropical is less than 1 meter per meter, so Lg cannot be less than 1.

When Lg is equal to 1, the m/m is used for each m/m, with a single straight line.

4) Lg is equal to n (n for integer), and n root is used for each meter of the pipe.

5) Lg is greater than 1 and is not equal to n, but the spiral wound is available, and the pitch is LS (m).

LS = PI (D + D)/(Lg2-1) 0.5 m... (6)

D is for pipe diameter (m); D is for electric companion tropical thickness (m)

6) the section of the pipe is in the tropical length.

L1 = the total length of the pipe... (7)

The 8.3.2 plane is partially powered by the tropical L2

1) the surface of each square meter shall be made of electric companion tropical length:

Lp = (Qp (Kc)/QM m / ㎡

2) Lp or greater 3, per ㎡ area shall be not less than 3 m laying length of electric tracing band.

3) the tropical length of the surface area is:

L2 = S......... (8)

S is the area of heat sink (m2). It can be treated as a flat container when the diameter is greater than 600mm.

The 8.3.3 pipe attachment is accompanied by the tropical length

The heat loss of the pipe attachment can be reduced to the heat loss of a certain length of pipe

Find out more about the products, technologies and solutions you need. Please leave us a message

Return To The Top