What are the principles and failure analysis of graphite heat exchangers?
- 2019-11-12-

Nantong Golden Triangle Graphite Manufacturing Co., Ltd. (Jiangsu Yulong Chemical Technology Co., Ltd.) is located in Nanhua Jiuhua Development Zone. It is one of the nation's larger graphite manufacturing companies. The company is committed to producing various impervious graphite equipment. Years of history.

The company invested 5.6 million in 2001 for reorganization registration, and in 2014 invested another 28 million to establish Jiangsu Yulong Chemical Technology Co., Ltd. to develop the manufacturing of special equipment (pressure vessels). Today, the company's workshop covers an area of 42,000 square meters and has more than ten patented technologies. It has developed a variety of graphite products that can replace imported equipment, greatly extending the service life of the equipment and reducing maintenance costs.

Nowadays, the company's products include graphite plates, round block type graphite heat exchangers, round block type graphite preheaters, round block type graphite falling film absorbers, floating head tubular heat exchangers, and tubular type Graphite falling film absorber, rectangular block-hole graphite heat exchanger, graphite heat exchanger in the kettle, two-in-one hydrogen chloride graphite synthesis furnace, three-in-one hydrochloric acid graphite synthesis furnace, round block-type graphite sulfuric acid dilution cooler, three Chloroacetaldehyde chlorination towers, graphite tower equipment and graphite chemical pumps have more than a hundred specifications, and various non-standard graphite equipment can be customized according to demand.

The new generation of graphite heat exchangers has superior performance and advanced processing technology. The graphite used for radiators is mainly artificial graphite. The processing technology of impermeable stone grinding equipment and its components is currently two types. One is to stick the tube sheet, tube bundle, baffle, etc. on the bracket with an adhesive, and then install the adhesive into the steel shell after the adhesive is cured, which is usually called assembling outside the shell. The other is The graphite heat exchanger is directly assembled in the shell after being trial-installed in the shell.

The performance of graphite heat exchanger equipment is as follows:

1, the surface is not easy to scale: graphite and most media have very little affinity, so dirt is not easy to adhere to the surface, especially used in condensation equipment and crystallization equipment.

2. Excellent corrosion resistance: Various types of carbon and graphite have excellent corrosion resistance to all concentrations of hydrochloric acid, phosphoric acid and hydrofluoric acid, including fluorine-containing media. The highest application temperature is 350 ℃ -400 ℃, that is, carbon The temperature at which graphite begins to oxidize.

3. Excellent thermal conductivity: Graphite has good thermal conductivity. It is a material with higher thermal conductivity than non-metallic materials. The thermal conductivity is 2 times that of carbon steel and 7 times that of stainless steel. Therefore, it is suitable for heat transfer equipment.

4. Resistance to certain high temperatures: The temperature of impervious graphite depends on the type of impregnating material. For example, phenol-impregnated graphite can withstand 170-200 ° C. If an appropriate amount of silicone resin is added to impregnate graphite, it can withstand 350 ° C. When phosphoric acid When deposited on carbon and graphite, the oxidation resistance of carbon and graphite can be improved, and the actual operating temperature can be further increased.

When the graphite heat exchanger is used, if it is used improperly, the tube will break or the bonding seam will leak. The reasons are as follows:

1. When the system warms up, because the heating rate is too large, it will cause the shell side pressure of the graphite heat exchanger to rise sharply, and the graphite tube will be damaged by impact.

2. Graphite heat exchanger tubes are unevenly heated.

3. Excessive force during cleaning will cause damage to the column.

4. Due to the increase of the graphite heat exchanger use time, some scaling will occur on the tubes. The scaling coefficient of the graphite heat exchanger is different from that of the non-scaled graphite heat exchanger. The thermal stress is overloaded, causing graphite The heat exchange tube is broken.