JPS5928229Y2 - acid cooler - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a cooler for sulfuric acid, nitric acid, phosphoric acid, etc.

An anode corrosion protection method was used in which a shell with a heat exchange chamber inside was connected to the anode side, a cathode rod was inserted into the heat exchange chamber, and a predetermined acidic liquid was supplied into the heat exchange chamber to cool the acidic liquid. For acid coolers, an oxide film is formed on the inner peripheral surface of the shell to prevent the shell from being corroded by the acidic liquid to be cooled.

Conventionally, from the viewpoint of corrosion resistance, the above-mentioned cathode rod has generally been made of... Steroid C (chemical components Ni 58 , Mo 17 -
19, Crll~14, MnO,2.

Si1. A bar made of Fe6-9) is used,
This steroid C has a very low electrical conductivity, comparable to nichrome wire.

On the other hand, since this cathode rod is long, the voltage drop is large.

Therefore, there is a problem that it is difficult to maintain the potential of the oxide film.

Therefore, the present invention provides an acid cooler that solves these problems.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

This embodiment relates to a shell-and-tube type cooler for cooling hot concentrated sulfuric acid.

1 is a stainless steel shell connected to the anode side,
Partition plates 2 and 3 are provided near both ends of the interior thereof to form a heat exchange chamber 4 in the center, and a communication chamber 5 is formed between one of the partition plates 2 and one end wall 1a of the shell 1. .

Further, a partition wall 6 is provided between the other partition plate 3 and the other end wall 1b of the shell 1 to form a cooling water supply chamber 7 and a cooling water discharge chamber 8.

9 is a cooling water supply pipe connected to the cooling water supply chamber 7, 1
0 is a cooling water discharge pipe connected to the cooling water discharge chamber 8, 1
1 is a large number of heat exchange tubes that pass through the heat exchange chamber 4 and communicate the cooling water supply chamber T button, the cooling water discharge chamber 8, and the communication chamber 5 with each other; 13 is a sulfuric acid supply pipe; and 14 is a nitric acid discharge tube. It's a tube.

15 is a cathode rod inserted into the heat exchange chamber 4 through one end wall 1a of the shell 1 and one partition plate 2,
- Consisting of an outer cylinder 16 made of steroid C and an inner cylinder 17 made of copper, copper alloy, aluminum, etc. with high electrical conductivity, which is inserted into the outer cylinder 16 and is brought into close contact with the outer cylinder 16. ing.

Numeral 18 is a tip cap whose small diameter portion is fitted into the tip of the outer tube 16 and welded to the outer tube 16, and 19 is a male screw of the small diameter portion that is screwed into a female screw on the inner peripheral surface of the proximal end of the inner tube 17. a proximal end cap welded to the proximal end of the outer cylinder 16 together with 2;
0 is a bolt that is screwed into a screw hole 21 formed in the cap 19; 22 is a nut that is screwed into the bolt 20; It is used for pressure contact.

If it is necessary to add a longer cathode rod 15, the following procedure can be used.

That is, as shown in FIG. 3, the inner cylinders 1 are butted against each other.
After welding 7 to each other 25, a connecting cylinder 26 made of Hastelloy C is arranged between the outer cylinders 16 facing each other, and both ends of the connecting cylinder 26 are welded 2T to each outer cylinder 16, respectively.

28 is an air hole for dissipating the heat of welding 27.

In addition, a piece 30 having an air hole 29 as shown in FIG.
After the male threads formed at both ends of the outer cylinders 16 are screwed into the female threads of the opposing cylinders 17, the abutted outer cylinders 16 may be welded together.

For the above configuration, hot concentrated sulfuric acid (90-98% H2SO4
, 50 to 130° C.) is supplied into the heat exchange chamber 4 through the supply pipe 13, and cooling water is supplied into each tube 11 through the supply pipe 9 button and the supply chamber 7.

As a result, the hot concentrated sulfuric acid is cooled by the cooling water, and the cooled concentrated sulfuric acid is transported to a predetermined location 1 via the discharge pipe 14.

Further, the cooled fresh water is discharged through the discharge chamber 8 and the discharge pipe 10.

On the other hand, when a current is passed between the shell 1 and the cathode rod 15, an oxide film is formed on the inner peripheral surface of the shell 1 in the heat exchange chamber 4.
This prevents the shell 1 from being corroded by the hot concentrated sulfuric acid that is being cooled.

As described above, according to the acid cooler of the present invention, the cathode rod is composed of a corrosion-resistant outer cylinder and an inner cylinder with high electrical conductivity inserted into the outer cylinder. Not only is the rod less likely to be corroded by the acidic liquid being cooled, but the voltage drop is small due to the action of the inner cylinder, even though the cathode rod is long.

Therefore, the potential of the oxide film formed on the inner peripheral surface of the shell can be maintained reliably.

Furthermore, the cost is low because the amount of expensive outer cylinders can be reduced to about half compared to the conventional method.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a schematic explanatory diagram, FIG. 2 is a longitudinal sectional view of the main part, and FIGS. 3 and 4 are longitudinal sectional views of the cathode rod addition location. DESCRIPTION OF SYMBOLS 1... Shell, 4... Heat exchange chamber, 7... Cooling water supply chamber, 8... Cooling water discharge chamber, 15... Cathode rod, 16
...outer cylinder, 17...inner cylinder.

Claims (1)

[Scope of utility model registration request] An anode corrosion protection method was used in which a shell with a heat exchange chamber inside was connected to the anode side, a cathode rod was inserted into the heat exchange chamber, and a predetermined acidic liquid was supplied into the heat exchange chamber to cool the acidic liquid. In the acid cooler, the cathode rod is provided with a corrosion-resistant outer cylinder;
An acid cooler comprising an inner cylinder with high electrical conductivity inserted into the outer cylinder.