Product Details

HRY, SRY TypeTubular Electric Heater
I. Purpose
SRY2 and SRY3 tubular electric heaters are used for heating oil in open or closed oil tanks. SRY4 tubular electric heater is used for heating flowing or circulating oil.
II. Specifications and Technical Data
1. Specifications and dimensions: see table and figure
 

Note: The mounting hole for SRY2 and SRY4 types is Ø72 mm

2. Working voltage tolerance: not greater than 1.1 times the rated value; the shell must be effectively grounded.

3. Working environment: relative humidity not greater than 95%, no explosive or corrosive gases.

4. Metal tube material: No. 10 steel.

5. Maximum working temperature: SRY2 and SRY3 are 300°C, SRY4 is 100°C.

6. Working pressure for SRY2 and SRY4 types: less than 2 kg/cm².

7. Fastener length for SRY3 type: 25 mm.

III. Usage, Maintenance, and Precautions

1. Dimension "B" in the outline drawing must be fully immersed in oil to avoid burning the element. The heated oil should be non-corrosive.

2. The working liquid level for SRY3 type must be below the fastener and above dimension line "B".

3. When melting solid oils such as asphalt and paraffin, reduce the voltage first, then increase to rated voltage after melting to prevent heat concentration and reduce element life.

4. If carbon deposits are found on the tube surface, they must be removed before reuse to avoid reduced efficiency or even burning out the element.

5. Store elements in a dry place. If insulation resistance drops below 1 megohm due to long-term storage, dry in an oven at about 200°C for several hours (or apply low voltage for several hours) to restore insulation resistance.

HRY, SRY TypeTubular Electric Heater

Tubular electric heaters consist of a metal tube, spiral resistance wire, and well-conductive and insulating electrical-grade magnesium oxide powder, along with lead terminals. They are widely used for heating liquids, air, etc. Common applications include water heaters, ovens, coffee makers, etc.

Materials:

Outer tube materials typically include In800, In840, 304, 316L, 310S, aluminum, copper, low-carbon steel, etc.

Magnesium oxide powder is selected according to different usage requirements, such as high-temperature powder, medium-temperature powder, etc.

The resistance wire is the heating element, generally made of two materials: Ni-Cr wire and Fe-Cr-Al wire.

Lead terminal materials generally include stainless steel and free-cutting iron.

Sealing materials include epoxy, silicone, glass, etc.

Process:

Heating tubes are made by inserting electric heating wire into an outer tube (carbon steel tube, titanium tube, stainless steel tube, copper tube), filling the gaps with magnesium oxide powder that has good thermal conductivity and insulation, then shrinking the tube. After heat treatment (some tubes do not require it), they are processed into various shapes as needed by the user. They have simple structure, high thermal efficiency, good mechanical strength, and good adaptability to harsh environments. They can be used for heating various liquids, acids, alkalis, and salts, as well as for melting low-melting-point metals.

Applications of tubular heaters: suitable for heating air, oil, water, chemical media, hot pressing molds, melting salts, alkalis, and low-melting-point alloys. They feature high thermal efficiency, long service life, high mechanical strength, easy installation, and safety and reliability.

Classification by shape: Heating tubes can be classified based on shape into straight single-end heating tubes, straight double-end heating tubes, U-shaped heating tubes, W-shaped heating tubes, special-shaped heating tubes, and spiral heating tubes.