Wear-resistant cut off thermocouple & thermal resistance

Wear-resistant thermal resistance

Wear-resistant thermal resistance is an ideal high-tech category for high-temperature wear-resistant environments such as circulating fluidized bed boilers in power plants, boiling boilers, coal pulverizer gas generators, and cement plant series of kiln heads, kiln tails, furnace hoods and chemical, smelting, etc. Dedicated products.

The wear-resistant thermal resistance is the same as the wear-resistant thermocouple, which is the circulating fluidized boiler of the power plant, the boiling boiler, the pulverizer gas generator and the series of kiln heads, kiln tails, furnace head covers and chemical, smelting, etc. A high-tech special product with a more ideal environment, wear-resistant thermal resistance draws on all the strengths, and uses a unique process formula to produce wear-resistant alloys in the out-of-balance balance. This product is compatible with ordinary stainless steel metal, cermet protection tubes, and similar wear-resistant alloys on the market Compared with the protection tube, its service life is increased by 1-5 times. Due to the environmental temperature difference, the temperature control point is too high, the vibration is large, the blower wind speed is too high, and the wear is serious, which makes temperature measurement very difficult, and the service life is very short. The wear-resistant alloy only wears through and damages, burns, breaks, and causes damage to the thermal resistance, which brings great losses and unnecessary trouble to the user.The wear-resistant thermocouple makes up for this shortcoming.

The wear-resistant thermal resistance is resistant to erosion, and the wear-resistant thermal resistance has been used by hundreds of manufacturers nearly 10,000 times a year, and the response is very good. It has the strength of leading peers in many occasions and is completely comparable to imported products. The wear-resistant thermal resistance is vibration resistant. , Wear resistance, corrosion resistance, high sensitivity, good stability, high accuracy, long service life and other advantages. It is the preferred temperature measurement protection tube in today's power plants, cement plants, chemical smelters and other wear-resistant fields.

Principle of temperature measurement

The principle of temperature measurement is based on the characteristic that the resistance of a conductor or semiconductor changes with temperature. It also has many advantages. It can also transmit electrical signals remotely. It has high sensitivity, strong stability, interchangeability and accuracy. However, it requires power supply and cannot instantaneously measure temperature changes. Different conductors have different electron densities. Because their electron densities are different, they produce a certain amount of electron diffusion. When they reach a certain equilibrium, the potential formed by the contact potential depends on the material properties of the two different conductors and their contact. Point temperature.

The wear-resistant thermal resistance adopts a three-wire system to eliminate the measurement error caused by the resistance of the connecting wire. This is because the circuit for measuring thermal resistance is generally an unbalanced bridge. The thermal resistance is a bridge arm resistance of the electric bridge, and its connecting wire (from the thermal resistance to the central control room) also becomes a part of the bridge arm resistance. This part of the resistance is unknown and changes with the ambient temperature, causing measurement errors. Using a three-wire system, one wire is connected to the power terminal of the bridge, and the other two are connected to the bridge arm where the thermal resistance is located and the adjacent bridge arm, which eliminates the measurement error caused by the wire line resistance.

System composition

(1) The thermal resistance temperature measurement system is generally composed of thermal resistance, connecting wires and display instruments. The following two points must be noted:

①The index number of thermal resistance and display instrument must be consistent

②In order to eliminate the influence of the resistance change of the connecting wire, a three-wire connection method must be adopted. See Chapter 3 of this chapter for specific content.

(2) Armored thermal resistance is a solid body composed of temperature sensing element (resistor body), lead, insulating material, and stainless steel casing. Its outer diameter is generally φ1~φ8mm, and the smallest can reach φmm . Compared with ordinary thermal resistance, it has the following advantages:

①Small size, no internal air gap, thermal inertia, low measurement lag;

②Good mechanical performance, vibration resistance and impact resistance;

③Can be bent, easy to install

④Long service life.

(3) End surface thermal resistance The end surface thermal resistance temperature sensing element is wound by a specially treated resistance wire, which is closely attached to the end surface of the thermometer. Compared with general axial thermal resistance, it can reflect the actual temperature of the measured end surface more accurately and quickly, and is suitable for measuring the end surface temperature of bearing bushes and other mechanical parts.

(4) Explosion-proof thermal resistance Explosion-proof thermal resistance through the junction box of special structure, the explosive mixed gas inside the shell is affected by sparks or arcs. The resistance body must change the length of the resistance wire and affect the resistance value. For this reason, it is better to replace a new resistor body. If welding is used for repair, it can only be used after welding.

working principle

Thermal resistance uses the characteristic that the resistance of a substance changes as the temperature changes to measure temperature. When the resistance value changes, the working instrument will display the temperature value corresponding to the resistance value.

Wear-resistant cut off thermocouple

The wear-resistant cut-off thermocouple increases the hardness of the steel by surfacing Ni+Wc35 on the wear-resistant head. It is suitable for the presence of high wear-resistant solid particles or fluids at the production site, and the thermocouple can be cut off when the protection tube is damaged. It is an indispensable temperature measuring device for catalytic cracking in oil refineries.

1. Application

By surfacing Ni+Wc35 on the wear-resistant head, the hardness of the steel is improved. It is suitable for the presence of high wear-resistant solid particles or fluids at the production site, and the thermocouple can be cut off when the protection tube is damaged. It is an indispensable temperature measuring device for catalytic cracking in oil refineries.

2. Main technical parameters

Flameproof grade: d‖BT4,d‖CT5

Nominal pressure: 2.5MPa