Special flue gas heating sampling tube for power plants

Corrosion protection sampling composite cable is an important part of the environment protection monitoring system. It is composed of inner core made of a group of corrosion protection resin tubes of high performance, self-regulating heating cable, constant power heating cable and compensating cable, insulation layer and flame retarded polythene (PE) protection jacket. The self-regulating function of self-regulating heating cable can ensure to maintain a certain temperature inside the sampling tube, then samples can be identical with the initial value, and finally ensure that the environment protection monitoring system can continuously and correctly take samples. Different materials can be selected for sampling tube of the corrosion protection composite tube according to composition of the sample and temperature, such as PFA ( polyethylene-fluoridated alkylvinylether), FEP(Fluoridated ethylene-polypropylene co-polymer), PVDF (polyvinyl fluoride), PE (flame retardant polythene) and nylon 610; medium/low/high temperature heating cables can be used; in addition, compensating conductors and power cables can be added as required by the customer.

The composite tube is a complex composed of several parts, and several systems are integrated on the limited section.

1. Sheath: CVC soft plastic, outdoor temperature: -70℃~70℃, acid/alkali corrosion resistance, compression strength: 1.0Mpa, no leakage.

2. Insulation material: Glass fiber cotton flame retardant 95g/m3, high efficient thermal insulation, light flame retardant material.

3. Tube core: stainless steel, high temperature resistant corrosion protection tube, the maximum temperature resistance is 600℃.

4. Heating cable: self-regulating heating cables and constant power heating cables (0-200℃) are provided. All cables shall be provided with explosion proof certificate, safe and reliable, suitable for using in industrial hazardous area.

5. Bending radius: the minimum radius of curvature of the composite tube is 0.5m.

Sampling system:

it can be assembled with several kinds of sampling tubes made of different materials such as Teflon PFA, FEP, PE, nylon 610, 12, copper tube, 316SS and 304SS.

I&C system: high efficient thermal insulation, flame retardant and light insulation layer; self-regulating heating cables or constant power heating cables.

Electrical system: It can be provided with instrument signal cables, compensating cables and control cables for display and monitoring of instruments.

Safety system: It can adapt to different process conditions, and can isolate the system from each other with aluminum foil or wire net to realize fire control security, electrostatic prevention and electromagnetic shielding; some systems can be provided with waterproof membrane and flame retardant anti-ultraviolet sheaths. The combination of multiple systems integrating several functions makes the complicate project simplified. It can guarantee the remote operation and remote diagnosis of the system. The heating system can ensure no condensate of gas inside the tube and keep it above the dew point for measurement, so the measurement accuracy can be ensured, which creates conditions for computerization of centralized control. The reinforced sheath can prevent it from damage arising from crossing and other factors.

Technical parameters

Electrical indicators

(1) Standard power of the self-regulating heating cable 15W/m (power at 10℃)

(2) Rated voltage: 220VAC

(3) The maximum heating length: 100~150m

(4) it is provided with a circuit breaker with 30A current; if the length of composite tube is not less than 50m, special auto current limiter shall be provided for the self-regulating heating cable.

(5) One circuit of the heat trace system

I&C indicators

(1) Maintain 40~50℃ temperature inside the tube at -20℃ ambient temperature and 15m/s wind speed.

(2) The sampling tube can resist acid/alkali corrosion, and its compression strength is 1.0Mpa with no leakage.

(3) The sampling tube can be used below <200℃ for a long period.

Installation indicator

(1) The minimum radius of curvature of the composite tube: 0.5m

(2) The maximum continuous length: 100~150m

(3) The lowest installation temperature: -10℃ (proper measures shall be taken at -30℃~-40℃)

(4) The minimum fixing distance: 5m in vertical direction and 2m in horizontal direction.