Steam boiler

Boiler introduction

The basis of boiler is based on the characteristics of pressure vessels. A boiler is a closed tank where the water inside is heated by the heat generated by the combustion of fuel consumed and eventually converted to high pressure water vapor.

The inner part of the boiler consists of two parts: fire tube and water tube.

All surfaces on the fire tube boiler are called heat surfaces. All the interior parts of a high pressure boiler are made of ferrous alloys.

Boilers are usually made of both cast iron and steel.  Cast iron boiler is a made due to lower resistant to producing low pressure steam. Currently most boilers are made of steel.

Pars dama boiler

Pars dama PDSB steam boiler in according with BS2790 and ISIRI 7911 standards which is designed and manufactures under the supervision and inspection of standard quality inspection company.

It has a variety of capacities ranging from 1100 to 6600 pounds per hour in wet back and dry back.

Pars dama boiler from 1 to 10 atmospheres and allow temperatures above 120 c ⁰.

Usage of boiler in industries

In different industries there is a need for warmth, heat and energy to perform their normal operations. These operations can be heating and baking of raw materials, melting or moving.

Designers are aware of the advantages of using indirect heating methods over direct processes, so they prefer to provide this thermal energy through various fluids such as water, gas or oil.

Water vapor has received a great deal of attention as a gas-forming fluid that is much hotter than hot water and also has high kinetic energy. Steam kinetic energy is used in various factories to circulate local turbines to generate electricity. High heat steam energy is also used in industries that require heating for heating and cooking.

Pars dama boiler capacity

Pars dama boiler is produced from a capacity of 250 kg/h , up to 3 tons per hour.

Boiler energy source

The energy required to produce steam or heat water is supplied by burning gas, gas oil or fuel oil. The boiler can also use two or three types of fuel simultaneously. Boilers are produced in both horizontal and vertical. Due to the explosiveness of this type of device, its manufacture must be in accordance with national or international standards.

Types of boilers

According to the type of steam boiler design, this product is designed in case of water tube and fire tube.

Water tube

In line with industrial developments over the past few decades, the use of high pressure boilers has become necessary caused catastrophic explosions. In those days, boilers consist of large diameter pressure vessels, which, under internal pressure, experienced expansionary stresses on the walls of these containers. The amount of this tension is known as ring tension. The best way to prevent this problem is to reduce the diameter of the pressure vessel, which is the basis of water tube boiler. Water tube boilers are made of containers called drums that are connected by pipe. The hot gas flows around the pipes and the water flows through the pipes so the water inside the pipes forms a water vapor in the vicinity of the hot air around the pipe. The capacity of free water tube boilers can be increased and this is one of the most important reasons for this type of boiler. A boiler with a capacity of 0.5 ton per second is capable of producing steam at a pressure of 160 atmospheres and a temperature of 55 c ⁰ .  smaller- sized boiler packs are made for use in the petrochemical industry.

Fire tube

This type of boiler usually consists of the main body of the front-and-back tubes, the furnace and the return chamber, which, after assembly and welding, have been thoroughly subjected to non-destructive testing (radiography, ultrasonic, penetrating fluid, etc.) then their tensioning operation is performed in a special furnace. The combustion chamber and boiler tubes are housed in a relatively large cylindrical chamber of large diameter. The boiler structure is such that the combustion gases pass through the pipes and thereby transfer heat to the water outside the pipes.  Fire tube boilers are manufactured and used in various industries for heating purposes as fixed boilers and portable boilers.

Fire tube boiler can be built in different capacities up to 25 tons per hour.  Fire tube boilers are designed to accommodate pressure and capacity because of a large pressure water tank and are usually designed for low pressure such as 6 atmospheres and les, and up to 10-12 atmosphere. Of course, this problem can be solved by increasing the thickness of the wall, which is economically limited.

Boiler classification

Boilers are divided into several categories according to the number of paths that the combustion gases go through to enter the chimney.

Two passes: to produce hot water, the gases from combustion pass through the boiler twice and then into the chimney.

Return furnace: the combustion gases traverse the furnace path twice and then pass through the pipes and move to the chimney. The efficiency of return furnace boilers is higher than that of two passes boilers.

Three passes: the boiler travels through the boiler three times and then enters the chimney to produce hot water and steam.

Four passes: it is produced to produce steam at high tonnage. The combustion gasses travel the pot four times and then enter the chimney.

Usages of boilers

One of the main uses of boilers Supplying the heating needed for various industries including food production, greenhouses, aviculture, mushroom breeding halls, etc. another use is as a cleaner and disinfectant, which is often referred to as hospitals, hotels and restaurants, large and small stores, city passages and industries such as paper making and plastic manufacturing. Steam for degreasing is also widely used in factories producing machinery. In many large industries, in addition to heating usages, steam power is used to supply electricity. Refineries are among these.

:The following can be considered as boiler and boiler users

Refineries

Factories producing industrial parts

Automotive factories

Concrete production

Dyeing of carpet and fabric

Production of tomato paste

Milk and dairy products

Production of candy and chocolate

Production of cakes, muffins and bread

Concrete curing

Cellulose and paper industry

Rubber industry

(Washing industry including carwashes, urban passages, public transport fleet (aircraft, train, subway, bus

Safety considerations in boilers over hot water boilers

Unlike hot or hot water boilers used in heating systems m steam systems are kept at much higher pressures and temperatures, making them more dangerous for public use than hot water boilers. Steam and boiler systems are in danger of being burned because the temperature in the boiler is too high (around 160- 180 c ⁰) and there is always a risk of explosion from all the boilers openings in the furnace and the pressure is spread in all dimensions of the furnace. A set of standard manufacturing capabilities and considerations must be taken into account in any boiler construction so that the user can work with high reliability, as if there is a problem with one or more systems, serious problems can arise.

Boilers quality differences

The most important difference in producing a boiler from a licensed and reputable manufacturer with an unauthorized manufacturer is that unauthorized boiler manufacturers do not guarantee their product.

Common processes performed by a reputable boiler manufacturer (with standard license with tracing number) include:

Technical map reviewed by the inspection organization approved by the standard organization

Verification of accuracy of steam boiler raw materials including sheets and tubes and resistant by the inspector on the certification of materials or laboratory results.

Control of boiler production processes from approved map

Compulsory non-destructive tests required by national standard4231

Supervision of hydraulic testing with pressure of 1.5 times the design pressure by inspection team

Presentation of certificate and license plate by inspector.

Specification od Pars dama steam boiler

Atmosphere pressure design of boiler 11 bar

Hydro static boiler pressure test at atmosphere pressure 16/5 bar

Atmospheric pressure 10 bar

All of the above are in accordance with Iranian standard 4231

Pars dama boiler controllers and valves

Steam outlet valve

Air evacuation valve

Reliable valve

Max hole valves – head hole hand hole (pn 16)

Explosion – proof ignition valve with unaltered steel springs MN4 17

Single – tap blow down valve with working pressure 16 bar (PN16)

Two items of honey wall pressure switch

A feeding pump device proportional to the boiler side

Water feeding valve, vertical degree 90

Manometer

Double sided glass with flange and special glass with Pyrex glass 800; one sided valve on feeding pump path.

Level control from double MC DONNEL- two burner gas and gas oil burner with valid European and Iranian brands.

All components are installed with valid European and domestic brands.