A sieve element of a tubular heat exchanger and its use in a tubular heat exchanger

Abstract

Sieve element of a tubular heat exchanger, featuring openings for a heat exchanger tubes, characterised in that formed along a rim (1) of the sieve element are notches (2) the edges (2a) of which are given an arched shape, preferably the shape of an elliptical arch, with arms (2a') parting away from each other towards the rim (1) of the sieve element, where the notches (2) are located behind the openings (3) for the heat exchanger tubes situated closest to the rim (1) of the sieve element.

Description

[0001] The invention concerns a sieve element of a tubular heat exchanger and its use in a tubular heat exchanger.

[0002] In the known tubular heat exchangers, flue tubes placed within a jacket inside of which water flows so as to be heated are fixed in sieve walls. To intensify the flow of the heated water, tubular heat exchangers can be fitted with transverse baffles featuring openings to accommodate the flue tubes. The baffle can contact the jacket wall with its edge, or there can be a peripheral gap formed between the partition and the jacket.

[0003] Known from document WO 2017 / 111636 A1 is a fired heat exchanger comprising a combustion chamber fitted with a sieve bottom and at least one transverse baffle, where the ends of the tube elements are anchored in the sieve bottom of the combustion chamber on the one side, and in the sieve wall on the other side. Moreover, the heat exchanger comprises a horizontal baffle with a single central opening for the flow of the fluid.

[0004] Known from document US 2012 / 0138278 A1 is a heat exchanger incorporating an external jacket with an internal set of vertical tube elements, where their opposite ends are fixed in the walls of the top and bottom sieves, and where the exchanger is fitted with a gas combustion chamber placed over the top wall of the sieve, as well as baffles mounted transversely with respect to the tube elements. The baffles feature openings for the tube elements. The top wall of the sieve is flat, while the top baffle is given the shape of a cone with its apex pointing down. The top baffle has a central opening in its middle area, and the outer diameter of the baffle corresponds to the diameter of the external jacket.

[0005] Known from document WO 2009 / 078577 A1 is a boiler which incorporates a set of flue tubes arranged in an external jacket in a water chamber. Ends of the combustion pipes are fixed to flat sieve elements. The water chamber features flat transverse baffles in the form of discs with openings for the tubes, where the diameter of the discs is smaller than the inner diameter of the external jacket so that formed between the baffle and the jacket is a gap for the flow of water.

[0006] The invention solves the problem of uneven distribution of flow of the working medium in a heat exchanger on the other side of the sieve element with respect to the direction of flow of the working medium through the sieve element, it further solves the problem of areas of stagnancy of the working medium which occur in the vortex trail behind the heat exchanger tubes.

[0007] The purpose of the invention is to solve the above problems.

[0008] The purpose has been achieved by designing notches in the edge of the sieve element and the shape of the notches for the flow of the working medium, where the notches enable even distribution of flow of the working medium on the other side of the sieve element with respect to the direction of flow of the working medium through the sieve element, it was also achieved by designing the number of the notches and their arrangement.

[0009] According to the invention, a sieve element of a tubular heat exchanger, comprising openings for heat exchanger tubes is characterised in that formed along a rim of the sieve element are notches the edges of which are given an arched shape with arms parting away from each other towards the rim of the sieve element, where the notches are located behind the openings for the heat exchanger tubes situated closest to the rim of the sieve element.

[0010] Preferably, the number of the notches is the same as the number of the openings for the heat exchanger tubes which are situated closest to the rim of the sieve element.

[0011] Preferably, the arched edge of the notches is given the shape of an elliptical arch.

[0012] The sieve element according to this invention can be used as the bottom of a combustion chamber of a tubular heat exchanger and / or as a transverse baffle of a tubular heat exchanger.

[0013] The shape of the notches formed along the rim of the sieve element for the flow of the working medium in a heat exchanger, the number of notches and their arrangement make it possible to achieve even distribution of flow of the working medium on the other side of the sieve element with respect to the direction of flow of the working medium through the sieve element, to increase the velocity of flow of the working medium, and to reduce the area of stagnation of the working medium resulting from the radial flow of the working medium through the heat exchanger. This enables reduction of the dead zone under the sieve element where the working medium gets stagnant, and leads to limiting the areas under the sieve element where boiling of the working medium as the result of its high temperature is highly probable. The solution according to this invention enables minimalisation of the areas characterised by high probability of working medium overheating and its boiling caused by its stagnation, where the boiling affects the durability and service life of the device.

[0014] The invention in its embodiments is shown on a drawing, where: Fig. 1 shows the sieve element viewed from the top; Fig. 2 depicts detail A, as in Fig. 1, in magnification; Fig. 3 presents a heat exchanger incorporating the sieve elements; Fig. 4 shows detail E, as in Fig. 3, in magnification.

[0015] An example of a sieve element of a tubular heat exchanger comprises openings 3 for tubes 8 of a heat exchanger, and notches 2 formed along the rim 1 of the sieve element with arched edges 2a having arms 2a' which part away from each other in the direction of the rim 1 of the sieve element. The arched edge 2a can, for example, take the form of an elliptical arch, as shown in Fig. 2. The said notches 2 are located behind the openings 3 for the tubes of a heat exchanger, situated closest to the rim 1 of the sieve element. The number of notches 2 is equal to the number of openings 3 for the tubes 8 of the heat exchanger which are situated closest to the rim 1 of the sieve element, as shown in Fig. 1.

[0016] The sieve element can take different shapes, as appropriate for the specific heat exchanger.

[0017] The sieve element can serve as the bottom 5 of a combustion chamber 4 of a tubular heat exchanger featuring a water jacket 7 around the combustion chamber 4, where the working medium flows into the water jacket encasing the combustion chamber 4, as shown in Fig. 3, Fig. 4, through the notches 2 in the rim 1 of the bottom 5 of the combustion chamber 4 and through the water chamber 9 inside which the flue tubes 8 of the heat exchanger are situated. The sieve element can also serve as a transverse baffle 6 of a tubular heat exchanger, as shown in Fig. 3.List of numerical references

[0018] 1 - rim of the sieve element 2 - notches for the flow of the working medium 2a - edge of the notch for the flow of the working medium 2a' - arms of the edge of the notch for the flow of the working medium 3 - openings for the tubes of a heat exchanger 4 - combustion chamber of a tubular heat exchanger 5 - bottom of the combustion chamber of a tubular heat exchanger 6 - transverse baffle of a tubular heat exchanger 7 - water jacket of a tubular heat exchanger 8 - tubes of a heat exchanger 9 - water chamber of a heat exchanger

Claims

1. A sieve element of a tubular heat exchanger, comprising openings for heat exchanger tubes, characterised in that formed along a rim (1) of the sieve element are notches (2) the edges (2a) of which are given an arched shape with arms (2a') parting away from each other towards the rim (1) of the sieve element, where the notches (2) are located behind the openings (3) for the heat exchanger tubes situated closest to the rim (1) of the sieve element.

2. The sieve element according to claim 1, characterised in that the number of the notches (2) is the same as the number of the openings (3) for the heat exchanger tubes which are situated closest to the rim (1) of the sieve element.

3. The sieve element according to claim 1 or 2, characterised in that the arched edge (2a) of the notches (2) is given the shape of an elliptical arch.

4. Use of the sieve element according to any one of the claims 1 to 3 as the bottom (5) of a combustion chamber (4) of a tubular heat exchanger.

5. Use of the sieve element according to any one of the claims 1 to 4 as a transverse baffle (6) of a tubular heat exchanger.

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