Explosion-proof Mineral Insulated Electric Heater for Flowing Liquid in Pipeline (hereinafter referred to as electric heaters) are heating devices designed to raise the temperature of the flowing medium in pipeline. The mineral insulated (MI) heating cable is used as the heating element. The structure is firm and durable, reliable in operation and long service life to ensure that the heated medium does not coke. It is suitable for the temperature rise of various flowable media, especially suitable for heating mediums with heavy, high viscosity or high temperature or quality requirements (such as crude oil, asphalt, residual oil, heavy diesel oil, animal fat and vegetable oils, etc.). It is widely used in various industrial sectors such as petroleum, chemical, pharmaceutical, metallurgy, glass, power generation, etc. Typical applications include offshore oil platforms, wellhead heating in oil fields, high-temperature atomization before combustion in oil-fired kiln, and centralized air-conditioning hot water boilers.

Second, technical properties

1. The heat transfer performance of the heating element of this product is good, and the temperature difference between the heating core and the metal sheath is small. At the same time, according to the process requirements, the surface heat load density of the heating element of the MI heating cable can be accurately designed. Under the premise of ensuring the total heating power, the heated medium will not coke. It solves the shortcomings of the traditional tubular electric heaters for long-term carbon deposition, blasting, core breaking and short life. The heating element can with a copper or a stainless steel sheath according to the application temperature and location.

2. The outer shell of the electric heater is welded by seamless steel pipe and flange. The overall structure is tight and firm and the pressure sealing performance is good for safe use. The normal working pressure is 0.6MPa~6.4MPa.

3. The device connection and electrical connection meet the explosion-proof requirements with an explosion-proof grade d IIBT1—T6.

4. Two sets of temperature sensors are installed in electric heater to detect the temperature of the oil and the surface temperature of the heating element. At the same time, the flow locking device can be optionally selected according to the user's needs. When the medium does not flow, the electric heater automatically stops heating.

5. No daily maintenance is required and it is easy to be installed and convenient to be maintained.

6. The product is practical and adaptable. Various non-standard types of electric heaters can be designed according to the different uses and special requirements put forward by users.

Note: When designing an electric heater for using outdoors, the explosion-proof junction box should have a rainproof shed to prevent rainwater from impregnating the gap of the explosion-proof surface through the wet insulation material.

Third, structure and working principle

1. Structure

The electric heater structure consists of nine parts. (See Figure 1)

1 Inlet pipe 2 Diversion Chamber 3 Heating Chamber 4 Temperature Measuring Resistor 5 Over Temperature Protector 6 Junction Box 7 Oil Outlet Pipe 8 Mixed Flow Chamber 9 Sewage Outlet

Figure 1: Schematic diagram of liquid electric mineral insulated heater

2. Working Principle

The cold medium enters the diversion chamber through the oil inlet, so that the medium flows into the mixing chamber along the periphery of the heating element, and the mixed medium flows out from the oil outlet at a uniform temperature. The mixing chamber is equipped with a temperature measuring sensor, and the temperature signal is collected and transmitted to the electronic control system. The temperature control instrument controls the primary circuit to realize automatic control of the oil temperature. When the oil products or electric heating element of the heater is overheated, the protection device automatically cuts off the power supply and the control cabinet emits an audible and visual alarm signal.

Fourth, technical specification

1. Model meaning

2. Technical data

The main technical data are shown in Table 1.

Table 1 Technical Data and Outer Dimension Sheet for Vertical Electric Heater

Table 2 Technical Data and Outer Dimension Sheet for Horizontal Electric Heater

Pasia Industries is a scientific and technological enterprise specializing in researching, developing, producing, installing and providing technical consultation and service for mineral insulated heating cables, heating elements and finished heaters as well as welded honeycomb products for filtering, shielding, sealing and guiding. Located in Puyuan high-tech park, Zhejiang province, it covers an area of more than 10 hectares, with a construction area of more than 50,000 square meters. It possesses a convenient transportation, about 150 kilometers from Shanghai in the north and 40 minutes from Hangzhou Xiaoshan international airport in the south.

With the most professional production lines and the highest automation level in China, Pasia produces mineral insulated heating cables, heating elements and finished heaters, honeycomb cores of stainless steel, brass, nickel, aluminium and other metal or metal alloys according to international standards. Pasia is one of the top four professional manufacturers of industry in the world on capacity and sales. As leading technological products, they possesses advanced properties of good quality, many varieties, full specification range, wide application, long service life, good safety and easy maintenance etc., and have been successfully applied to oil and gas (extraction, transportation, storage, etc.), chemical industry （petrochemical industry, fine chemical, pharmaceutical, etc.), power (nuclear power, solar power, etc.), construction (melting ice and snow), railway, aviation, metallurgy, electronic and et al for the applications as heat tracing and heating, detecting, signaling, power transmission, as well filtering, shielding, guiding and sealing. The company has become one manufacturer of the few in the world of completely electric heating technology and products of four categories including constant wattage, temperature self-regulating, MI heating cable and skin effect resistance and one of the top three wire electric heating products suppliers. The honeycomb core has been widely used by many clients on filtering, water treatment, structure platform with high requirement on flatness, shielding, turbine sealing and straightening etc. It can not only provide complete categories of professional products, also provides customers with solutions, consulting, project reply, EPC project general contracting services which can even be extended to the services including safe operation for maintenance etc. So far, the company has possessed 25 related patented technologies, 13 national new products, and 12 national technological innovation projects.

Upholding a company spirit of leading innovation and win-win cooperation, Pasia has become one of the few in the industry who possesses complete capacity of research and development, design, production and installation of mineral insulated heating cable and its heating equipment, honeycomb core and its parts or modules both home and abroad, relying on professional team, advanced management means, close work with related universities, design institutes and scientific research units, industry leading R&D testing capacity, under the ISO9001 quality system. After several years’ hard and persistent efforts, Pasia have the ability to supply a complete set of products, excellent technical support and perfect follow-up service. A variety of products have not only been applied to meet the requirements from domestic market, but also exported to many countries and regions such as Europe, Asia, Africa and America to serve different categories of purposes. It receives a high visibility and reputation from the industry. Over the past years, the company has involved in thousands of projects from all walks of life, among which the most influential ones are:the explosion-proof natural gas electric heater at Datong natural gas gate station in Shanxi province; Electric heater for paint material for the production bases of Hempel (USA) paint company in Kunshan and Guangzhou; Electric heaters for Tongyi chemical system in Beijing, Lanzhou, Shanghai and Shandong; Complete heating and tracing equipment for large oil and gas fields in Jiangsu oilfield, Benin, Angola, Thailand, Myanmar, Kazakhstan, the UK, Canada; the wind or water tunnels of honeycomb core in Singapore, India, USA and UK, shielding honeycomb core applications from many foreign countries, honeycomb seals for the turbines from Russia etc.

Insists on serving market with sincerity, securing quality with technology, leading innovation with study and driving development with passion, Pasia has become a well-known provider of advanced heating technology solutions at home and abroad, and one of the fastest growing members in the industry.