Reciprocating Boiler Grate Specific Description

　　ReciprocatingBoiler GrateSpecific Description

　　The reciprocating boiler grate is a small mechanized grate developed on the basis of a fixed step grate. It has characteristics such as simple structure, easy manufacturing, low metal consumption, and good dust removal effect. It is widely used in small industrial boilers and is a combustion device with great development prospects.

　　The structure forms of reciprocating grates include: inclined reciprocating grates, horizontal reciprocating grates, and water-cooled reciprocating grates. The inclined reciprocating boiler grate structure has two types, one is the more common general inclined reciprocating grate, and the other is the water-cooled reciprocating grate developed in recent years.

　　Generally, the inclined reciprocating boiler grate mainly consists of fixed grate pieces, movable grate pieces, transmission mechanism, and reciprocating mechanism. The entire combustion surface of the grate is composed of fixed grate pieces and movable grate pieces, which are stacked in a stepped manner and inclined at 15 to 20 degrees. The fixed grate pieces are installed on the fixed grate beam, which is then fixed to the inclined channel steel support. The movable grate pieces are installed on the movable grate beam, which rests on the rollers released at both ends of the fixed grate beam. The lower ends of all movable grate beams are connected into a whole by connecting rods.

　　When the motor starts, the transmission mechanism drives the eccentric wheel through the movable rod, connecting rod, push-pull shaft, and connecting rod, causing the movable grate pieces to reciprocate on the fixed grate pieces. The reciprocating stroke is generally 30 to 70 mm, and the coal moves down and back accordingly. The motor is controlled by a time relay, and the on-off time is adjusted according to the requirements of different boiler loads and coal types.

　　Water-cooled ReciprocatingBoiler GrateIt mainly consists of butterfly-shaped cast iron grate pieces, water pipe frames, transmission mechanisms, and reciprocating mechanisms. The water pipe frame consists of a row of straight pipes welded at both ends to the header, with the front and rear headers connected to the connecting pipes and steam drums, forming a circulation loop. The butterfly-shaped cast iron grate pieces are embedded between the pipes of the water pipe frame, and the contact surface between the grate and the pipes is coated with metal powder mixed with water glass, and tightly formed with modules. The flow of boiler water cools the butterfly-shaped cast iron grate pieces. Behind the inclined reciprocating grate, some are equipped with burnout grates (also known as booster grates). The ash basically burns off all the combustible materials on this grate, and then the grate is flipped over to dump all the ash. Due to severe air leakage caused by burning the grate, air regulation is complicated, and the ash pit is often sealed with water, with periodic or continuous ash discharge.

　　When the inclined reciprocating grate is used with coal that has a high volatile content and ignites quickly, it is easy to burn at the coal hopper outlet, causing smoke from the coal hopper. To eliminate this defect, secondary air can be blown through the coal door to direct the flame into the furnace. However, a more thorough solution is to improve the coal feeding device below the coal hopper, allowing the coal to leave the hopper and then be fed deep into the furnace through the coal feeding plate before combustion.

　　The inclined reciprocating boiler grate is the same as the chain furnace. To ensure smooth ignition of the coal and enhance the mixing of gases in the furnace, it is also necessary to arrange the furnace arch. For the specific situation of the reciprocating grate, a relatively simple inclined front arch can generally be used. When burning bituminous coal and lignite, some do not have a low and long rear arch, but instead use a middle arch or a middle partition wall to match the front arch, helping the new coal to ignite. The middle arch or partition wall can be completely vertical or vertical at the bottom and inclined forward at the top. When burning bituminous coal, a vertical rear partition wall is often used, and some slag blocking arch doors are also set up, which extend a small arch door on the rear wall to dissipate heat into the burnout area, allowing ash and slag to be completely burned.