JP5528344B2 - Staircase burning grate - Google Patents

Description

  The invention relates to a stepped fuel grate of the kind described in the introductory part of claim 1.

  This type of stepped fuel grate is known to have a grate beam, which compensates for the temperature difference along the length of the beam and thereby causes that temperature difference. In order to minimize the difference in width between the two ends, a heat transfer medium is passed therethrough. This type of staircase burning grate is, for example, a stepped grate at the bottom of the heat transfer medium duct to provide a constant duct cross section, i.e. a constant flow of heat transfer medium in the duct. It is known from US Pat. Providing a duct having this configuration means that a relatively large number of individual parts are assembled by welding, resulting in a relatively complex and time-consuming manufacturing process.

  U.S. Pat. No. 6,089,089 discloses a stepped combustion grate adapted to pass combustion air therethrough that may be responsible for providing some degree of cooling of the grate. Combustion air under the grate for introduction into the fuel on the top of the grate after passing along the lower side of the grate for heat transfer contact with the lower side of the grate An air seal is provided. In any case, the structure shown in this document allows a certain amount of leakage of the heat transfer medium, i.e. combustion air, since the heat transfer medium is subsequently led into the combustion chamber after passing under the grate. .

International Publication WO96 / 23174 U.S. Pat. No. 4,563,959

  Based on this prior art, the object of the present invention is to provide a stepped fuel grate of the kind described above, which reduces the number of individual components that must be welded together during manufacture. This object can be achieved with a stepped combustion grate of the kind described above, which stepwise fuel grate also comprises the features described in the characterizing part of claim 1 according to the invention . With this configuration, only two main components are used to provide a staircase grate and a block for the heat transfer medium.

  Another object of the invention is to maintain the circulation of the heat transfer medium through a mainly constant cross section just below the top of the grate, which is achieved using a staircase grate of the kind described above, This staircase grate also comprises the features described in the characterizing part of claim 2 according to the invention. With this configuration, the flow of the heat transfer medium just below the top of the grate is maintained at a constant level along the stepped grate beam by having a mainly constant cross section for this flow.

  A further object of the present invention is to provide a stepped combustion grate of the kind described, which allows a liquid heat transfer medium to be circulated, preferably in a closed loop. Preferably, the liquid transmission medium used is water and the closed loop circulation can be effected under pressure.

  Further advantageous features, which will be apparent from the detailed part of the description, are described in the dependent claims.

  In the following detailed part of the specification, the invention will be explained in more detail with reference to the drawings.

It is a sectional side view which shows the stair-like grate for the combustion grate by this invention. It is a top view which shows the staircase grate of FIG. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1 showing the stepped grate of FIG. 1.

  The staircase grate beam 1 shown in FIGS. 1 to 3 comprises a grate top 2, which is connected to each other by a weld 14 in a portion extending mainly vertically. Stepped grate top plates 2A and 2B. Between these two grate top plates 2A and 2B, a groove 13 provides a primary air opening for introducing primary air from a primary air chamber positioned under the stepped grate beam 1. .

  A block 4 for the heat transfer medium is provided in the form of U-shaped plate elements 5A and 5B, the sides of which are cut into steps corresponding to the stepped grate tops 2A and 2B, respectively. It is welded to the lower surfaces of the plates 2A and 2B, leaving a space between the two U-shaped plate elements 5A and 5B and providing access to the primary air opening 13 for the primary air. The first dividing plate 6, formed in the stairs corresponding to the stairs of the grate top plate 2, provides a mainly constant cross section for the heat transfer medium flow directly under the grate top 2. , Positioned inside the blocking part 4. In order to divide the block for the heat transfer medium under the first dividing plate 6 into an inlet chamber 8 and an outlet chamber 9, at a suitable position between the two ends of the stepped grate beam 1, The second dividing plate 7 is positioned below the first dividing plate 6. The inlet chamber 8 includes an inlet connecting portion 10 for supplying the heat transfer medium to the sealing portion 4, and the outlet chamber 9 includes an outlet connecting portion 11 for discharging the heat transfer medium from the sealing portion 4. As shown in FIG. 3, two separate sealing parts 4A and 4B for the heat transfer medium are connected in series by connecting the outlet connection part 11 from the sealing part 4A to the inlet connection part 10 of the sealing part 4B. Connected to Of course, other methods of connecting the inlet connection 10 and the outlet connection 11 can be used, and several stepped grate beams 1 positioned across the stepped grate can be of any convenience. It can be connected in parallel and in series.

  The series connection 12 is provided by a flexible tube to allow some expansion or contraction due to temperature fluctuations.

  The stepped grate beam 1 shown in FIG. 1 is intended to be used to circulate water or other liquid heat transfer medium, while filling the seal with water or a similar liquid heat transfer medium. In order to remove any air that may be present inside the block 4, the tube 16 extends from the upper part of the block 4 to a suitable position below the stepped grate beam 1 inside the block 4. A shaped air escape system 15 is provided. The outlet 17 from the tube 16 comprises a valve that is opened to release air from the air escape system 15.

  Referring to FIG. 2, the outer surface of the staircase grate beam 1 comprises a wear plate 3, which is adjacent to the staircase when the staircase grate beam 1 is positioned in the staircase grate. It can be seen that it is positioned to slidably abut against a corresponding wear plate on the grate beam 1.

  An incineration or combustion plant with a staircase grate beam 1 as described above will usually comprise a number of grate compartments, each of which is obliquely downward in the direction of fuel movement on the top of the grate. A plurality of grate beams extending to Each of the grate compartments can be provided with a staircase grate beam 1 according to the invention, the purpose of having a heat transfer medium circulating through the staircase grate beam 1 is as follows: It is to make the temperature on the grate beam 1 uniform, and secondly, to make the temperature on the grate compartment with such a stepped grate beam 1 uniform. A further purpose of circulation of the heat transfer medium is to either heat or cool the fuel on top of the staircase grate beam 1 in order to control the combustion of fuel on the staircase grate compartment. possible. That is, it may be advantageous to circulate a high temperature heat transfer medium in the staircase grate beam 1 in the feed section where the fuel material is heated and optionally dried, It may be advantageous to circulate a cooler heat transfer medium in the subsequent grate compartment to be burned. In this connection, the pressure in the closure 4 is kept high enough to prevent boiling of the water, so that the water can be circulated at a temperature higher than 100 ° C. without boiling. It may be advantageous to have a block for the heat transfer medium that is constructed to maintain high pressure. Further, in some situations, it may be advantageous to circulate other types of heat transfer media within the stepped grate beam 1, such heat transfer media may include various gases such as the atmosphere, water, , Various types of liquids such as heat transfer oil, or water vapor.

  In the drawing, it is shown that the staircase grate beam 1 includes two grate beam modules each comprising a staircase grate top 2A, 2B, two blockages for the heat transfer media 4A, 4B, and the like. As shown in the drawing, the two grate beam modules A and B are provided in two different widths, and using these two widths, two modules A, two modules A and B, and two modules B And B, respectively, can provide the resulting stepped grate beam 1 of three different widths. In the preferred embodiment, module widths A and B are selected to be approximately 170 mm and 130 mm, resulting in possible stepped grate beam widths of 260 mm, 300 mm, and 340 mm, respectively. With this module width selection, as long as more than three stepped grate beams 1 are provided next to each other in the grate compartment, the stepped grate beams 1 can be selected appropriately from the above combinations. Thus, the grate section width can be constructed within 40 mm. Typically, stepped grate beams positioned side-by-side are alternately fixed and movable to move fuel on top of the grate forward in the fuel chamber, ie down along the stepped grate It becomes.

  Although the present invention has been described above with reference to one particular embodiment thereof as shown in the drawings, those skilled in the art will envision many modifications without departing from the scope of the appended claims. Can do.

Claims (7)

A stepped combustion grate for an incineration or combustion plant, wherein the plant comprises one or more grate compartments, each grate compartment comprising a plurality of grate beams (1), Each grate beam (1) extends obliquely downward in the direction of fuel movement on the top of the grate, and the grate beam (1) is downward in the direction of movement of fuel on the top of the grate And a grate beam (1) adjacent to each other, having a grate top (2) stepped into the rim, and having an outer surface (3) closely adjacent to each other across the width of the fuel grate. ) Is reciprocable relative to the direction of movement of the fuel on the top of the grate and the grate beam (1) is adapted to a possible closed loop passage of the heat transfer medium therethrough In the cylindrical combustion grate, the block (4) of the heat transfer medium is One or more U-shaped bent plate elements (5), the sides of which are cut stepwise corresponding to the stepped grate top (2), and the underside of the grate top (2) is welded to,
A first dividing plate (6) is further provided inside each heat transfer medium blocking portion (4), and the first dividing plate (6) includes a step corresponding to the grate top (2). Formed and positioned at a constant distance from the grate top (2) so as to provide a predominantly constant cross-section for the heat transfer medium flow directly below the grate top (2),
A second dividing plate (7) for dividing the volume under the first dividing plate (6) inside the sealing part (4) into an inlet chamber (8) and an outlet chamber (9); The inlet and outlet chambers (8, 9) are arranged in the vicinity of the second dividing plate (7) for supplying a heat transfer medium to the sealing part (4) and discharging it from the sealing part (4). A stepped fuel grate characterized by comprising inlet and outlet connections (10, 11) positioned on both sides . Each grate beam (1) comprises two sealing parts (4A, 4B), the sealing parts (4A, 4B) for the flow of the heat transfer medium passing through the sealing parts (4A, 4B) The staircase combustion grate according to claim 1 , wherein the staircase combustion grate is connected in series with each other. Each grate beam (1) is provided with a primary air opening (13) in the form of a series of longitudinally extending grooves (13), said primary air opening (13) being said blocking part (4A, 4B). ), In communication with the primary air space below the grate (1) and in the middle of the grate top (2A, 2B). stepped combustion grate according to 2. 4. The groove (13) according to claim 3 , characterized in that the groove (13) is provided in the mainly horizontally extending part of the grate top (2A, 2B) over the entire length of the horizontally extending part. Stepped combustion grate as described. Each grate beam (1) is provided by two grate beam modules, said modules each having a grate top (2A, 2B) and a block (4A, 4B), in the form of a groove (13). Positioned relative to each other so as to provide the primary air opening (13), the primary vertical groove (13) is located at the top of the stepped grate top (2A, 2B). Step-like form according to any one of claims 1 to 4 , characterized in that it is connected to one another by welding in order to ensure that it only opens into the mainly horizontal surface of the grid top (2A, 2B). Burning grate. The grate beam module is provided with two widths A and B, and a combination of A + A, A + B, and B + B provides three different width grate beams (1), respectively. Item 6. A stepped fuel grate according to item 5 . The closure (4) is characterized in that it is constructed to provide a closed-loop circulation of the heat transfer medium, stepped fuel grate according to any one of claims 1 to 6.

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