JPH0147257B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a helical baffle plate for supporting multiple tubes in a shell of a shell-and-tube heat exchanger.

It is well known that in multi-tubular heat exchangers, in order to increase the efficiency of heat exchange between the fluid flowing inside the body and the fluid flowing inside the tubes, a baffle plate is provided to allow the fluid inside the body to flow in a direction across the tubes. It is.

There are various shapes of baffle plates, and the most commonly used baffle plate is an arc-shaped baffle plate with a portion of a disc cut out. That is, the notches of the disks are placed in the body at alternating opposite sides at desired regular intervals so that the fluid flows in a meandering manner across the tube at right angles. The size of the notch is determined by taking into consideration the flow rate, flow rate, etc., but since the fluid passes through this notch and repeatedly changes direction by 180 degrees, pressure loss occurs each time the direction changes. There were problems such as fluid stagnation in the corner surrounded by the baffle plate and the body, interfering with heat exchange.

On the other hand, the heat exchangers disclosed in Japanese Unexamined Patent Application Publication No. 48-65547 and Japanese Utility Model Application No. 55-73190 are equipped with a spiral baffle plate that follows the natural flow of the fluid. Since it can be formed into any shape, pressure loss is significantly reduced, and since there are no fluid stagnation points, it has the advantage of extremely high heat exchange efficiency, and is particularly suitable for heat exchangers that handle high viscosity oil. However, in the case of heat exchangers in which one or more coils are twisted and a continuous flow path is formed by a helical baffle plate, the baffle plates and the central shaft are currently integrated into one piece by casting. They are manufactured by molding, and larger ones are manufactured by molding baffle plates and central shafts of appropriate length by casting and connecting them one after another. Therefore, molds and other casting equipment are required, which is extremely troublesome, and since it is a cast product, the wall is thicker than necessary, resulting in a lot of wasted material.

The present invention solves these problems and provides a method for manufacturing spiral baffle plates, both large and small, at low cost and easily.

That is, the method for manufacturing a baffle plate for a shell-and-tube heat exchanger according to the present invention involves providing a pilot hole in an annular plate member having a circumference of one pitch or less, and sandwiching this plate member between two mold members. Then, by press working, it is bent into a twisted shape to form a part of a spiral, and its inner and outer peripheral edges are bent at right angles to form a rib, and at that time, the prepared hole is made into a secondary shape. It is characterized in that it is processed to form a tube support hole that has ribs bent at right angles to the periphery and is projected in a perfect circle on a plane perpendicular to the center axis of the spiral, and this baffle plate is attached to the outer peripheral surface of the center axis. A continuous coil-shaped flow path can be formed by sequentially connecting the coils along the flow path.

Next, embodiments of the present invention will be described according to the drawings.

Figures 1, 2 and 3 are exploded views of the mold, showing a lower mold member 1 and an upper mold member 11 disposed facing each other.
It consists of a guide member 21.

The two mold members 1 and 11 are formed into a notched cylindrical shape with a circumference of three-quarters, and the lower mold member 1 has an inclined end face 2 corresponding to a spiral of a predetermined pitch on its upper surface, and a guide penetrating vertically. It has holes 3 at predetermined intervals. The upper mold member 11 has an inclined end surface 12 corresponding to the same spiral as described above on the lower surface, and has a guide hole 13 disposed on the same center as each of the guide holes 3, and has an outer peripheral edge of the inclined end surface 12 and a guide hole 13 disposed on the same center as the guide hole 3. Projections 1 are provided on the inner periphery and the periphery of the guide hole 13, respectively.
4, 15, and 16 are formed.

The guide member 21 has a flat plate-like base 22 protrudingly provided with a protrusion 23 that tightly fits into the center hole 6 of the lower mold member 1 and a guide rod 24 that fits loosely into each guide hole 3 and projects from the inclined end surface 2. It is composed of

4 and 5 show a metal plate member 41, which is the material of the baffle plate, which is formed into an annular shape slightly longer than the circumference of three-quarters of a circle, and which is closer to the inclined end surface 2 of the lower mold member 1. It also has a slightly larger width, and the portion surrounded by the two-dot chain line 41a in FIG. 4 substantially serves as a baffle plate. Further, this plate member 41 has guide holes 3 and 1.
A pilot hole 42 corresponding to 3 is provided, and a plate member 41 of a desired shape is formed by punching a metal material plate.
and the pilot hole 42 are formed all at once.

FIGS. 6 to 9 show a plate member 4 using the above-mentioned mold.
1 into a baffle plate.

First, the protrusion 23 is fitted into the center hole 6, the guide member 21 is stacked on the lower mold member 1, and the guide rod 24 is loosely and concentrically fitted into each guide hole 3 to protrude from the inclined end surface 2 (sixth figure). Second, the plate member 41 is placed on the inclined end surface 2 by fitting the pilot holes 42 into the guide rods 24 (FIG. 7). Third, the upper mold member 11 is moved toward the lower mold member 1 with its guide hole 13 almost tightly fitted into each guide rod 24, and the plate member is inserted between the opposing inclined end surfaces 2 and 12. 41 and bent into a twisted shape corresponding to a spiral of a predetermined pitch (FIG. 8). During this bending, the pilot hole 42 is secondary processed by the guide rod 24,
A support hole 52 is formed that is projected in a perfect circle on a plane perpendicular to the center axis of the spiral.

In the illustrated embodiment, the outer periphery 4 of the lower mold part 1 and the inner periphery 5 of the guide hole 3 and the upper mold part 1
A plate member 41 is placed between each of the projecting edges 14, 15, 16 of 1.
A gap is provided which is approximately the same as the wall thickness of the inner peripheral edge 43 and outer peripheral edge 4 of the plate member 41 shown in FIG.
4 is bent at a right angle, and the peripheral edge of the pilot hole 42 is also bent at a right angle, which prevents the spring back of the baffle plate 51 obtained by removing it from the mold after completing the process shown in FIG. Ribs 53, 54, and 55 are formed to ensure stable contact with the body and tube.

Finally, extra length portions 45, 45 at both ends of the plate member 41
A baffle plate 51 as shown in FIGS. 10 and 11 is formed by punching out holes 56 for caulking and holes 57 for inserting baffle rods in order to sequentially connect the baffle plate 51 to the baffle plate 51.
complete.

FIG. 12 shows a shell-and-tube heat exchanger having baffle plates 51 manufactured by the above process. This heat exchanger has a baffle plate 51 on the outer peripheral surface of the central shaft 61.
The inner peripheral edges of the baffle plates 51 are brought into contact with each other almost without a gap, and adjacent baffle plates 51 are successively connected to each other by caulking to form a continuous spiral baffle plate 62 of a predetermined length, and guide plates 63 extending in the central axis direction at both ends thereof.
64, and then connect one tube plate 65 to the center shaft 61.
Attach it to one end, insert the tube 66 through the hole of this tube sheet 65 and the support hole 52 of the baffle plate 51, arrange it parallel to each other, fit the body 67, and then attach the other tube sheet 68. two tube sheets 65, 6
It is assembled by providing bonnets 69 and 70 on the outside of 8.

The plate member 41 may have a length that arbitrarily divides the circumference of one pitch or less into equal parts, but the pilot hole 42 is formed when the molded baffle plates 51 are sequentially connected and assembled into a continuous spiral shape. They must be formed so that they are aligned on mutually parallel axes. Furthermore, the baffle plates 51 can be sequentially connected by welding instead of caulking, and in this case, the extra length portion 45 is not necessary.

Note that the projecting edges 14, 15, 16 of the upper mold member 11
may be provided in the lower mold member 1, and the support hole 5 may be provided in the lower mold member 1.
A guide rod 24 for secondary processing 2 is provided on the lower or upper mold members 1, 11, and the opposing mold members 1, 11
A mold having guide holes 3 and 13 into which the guide rod 24 is fitted may be used.

As described above, according to the present invention, an annular plate member with a circumference of one pitch or less is bent and formed by press working to form a part of a spiral. It can be molded extremely easily. In addition, for the support hole that penetrates the pipe, a pilot hole is prepared in advance in the plate member, and this is formed by secondary processing during press processing, so the process of punching out the material plate and making the plate member with the pilot hole is required. This is manufactured through a process of press working and bending, and large and small baffle plates can be manufactured easily and at low cost. Since the plate members are bent into a twisted shape, when they are connected one after another, they are formed into a shape that follows the natural flow of the fluid, resulting in a heat exchanger with low pressure loss and extremely high heat exchange efficiency. .
Furthermore, since ribs are provided on both the inner and outer edges of the plate member and on the periphery of the support hole, spring back is prevented and a baffle plate of a predetermined shape can be obtained, as well as stable contact between the center shaft and the body. This, together with the fact that the support hole is projected in a perfect circle on a plane perpendicular to the center axis of the spiral, allows the tube to be easily penetrated and supported stably.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a front view of the mold, FIG. 2 is a plan view of the lower mold member, FIG. 3 is a bottom view of the upper mold member, and FIG. 4 is a view of the plate member. The plan view, Figure 5 is the front view, Figures 6, 7, and 8.
The figure is a vertical cross-sectional view of the pressing process order, Figure 9 is an enlarged partial view of Figure 8, Figure 10 is a perspective partial view of the baffle plate, Figure 11 is a front view of the baffle plate, and Figure 12 is the book. 1 is a longitudinal sectional view of a shell-and-tube heat exchanger equipped with a baffle plate manufactured according to the invention; FIG. DESCRIPTION OF SYMBOLS 1... Lower mold member, 2... Inclined end surface, 3... Guide hole, 11... Upper mold member, 12... Inclined end surface, 13
...Guide hole, 24...Guide rod, 41...Plate member, 42...
Pilot hole, 51...Baffle plate, 52...Support hole.

Claims (1)

[Claims] 1. A pilot hole is provided in an annular plate member having a circumference of one pitch or less, and this plate member is sandwiched between two mold members and bent into a twisted shape so as to form a part of a spiral by press working. At the same time, the inner peripheral edge and the outer peripheral edge are bent at right angles to form a rib, and at that time, the pilot hole is subjected to secondary processing to have a rib bent at right angles to the peripheral edge and perpendicular to the helical center axis. A method for manufacturing a baffle plate for a multi-tube heat exchanger, characterized by forming tube support holes projected in a perfect circle on a surface.