Cooler Introduction
Read the number：(2867) Time：2014/3/4 18:07:52
Coolers
First, an overview out of the cooler is a heat exchange device metallurgy, chemical industry, energy, transportation, light industry, food and other industries widely used. It is suitable for cooling, condensation, heating, evaporation of the different conditions, heat recovery and the like. Due to its rugged construction, the use of flexibility, adaptability, in recent years, but also on aspects of the structure, processes and materials made a lot of improvements to make it more reasonable technical performance and advanced. Thus, many of the categories in the heat exchanger, cooler, tubular heat exchanger still occupies an important position.
Second, the structure and working principle
Out of the cooler by an external shell, interior cooler body composed of two parts. Due to the specific structure of different ways, from the outside into the form of pipe threaded connection and flange; from installation into the form of horizontal and vertical; from floating into the form of a floating disc and floating-head; tube structure from the cooler into spiral tube and fin tube; from baffle structure is divided into a variety of structural forms segmental baffles, rectangular baffles, double weir baffle and round-shaped baffles, etc., according to the specific conditions Optional.
External housing includes: cylinder, watershed cover and backwater cover. Which is provided with inlet and outlet tubing and into the outlet, to understand the rules of baccarat, and has a drain, drain, vent plug, zinc rod mounting holes even thermometer interface.
Cooler body from the cooler tube, fixed orifice plate, moving well plate, baffles and other components. Cooler tube with both ends fixed, moving hole plate connections, drain the oil cooler loaders cooler inside; fixed orifice plate flange and the outer body, moving hole plate can freely retractable outer body to eliminate the temperature on the cooler tube due the impact of thermal expansion and contraction. Baffled stiffened enhanced heat transfer and cooler tube support role.
Out of the cooler's heat medium is taken over by imports barrel on the order of the flow path through each fold, zigzag flow to take over the exports. After cooling medium and is a dual flow tube that cooler medium from the inlet manifold cover through the cooler into the half pipe, and then flows into the other half from the backwaters cover tube into the other side of the cooler lid and outlet manifolds . Cold medium in the double tube flow process, absorb heat medium heat emitted from the exhaust outlet of the working medium to maintain the nominal operating temperature.
Third, the use and operation
1, the cooler's base must be sufficient to sink the cooler does not occur in the cranial end plate holes should be left enough space to pull out from the casing tubes, cooler place when lifting specifications shall, subject to the level of alignment after tightening the anchor bolts, and out of the tube connecting the hot and cold media.
2, before the cooler starts to be exhausted air cavity, in order to improve heat transfer efficiency, comprising the steps of:
(1) to release heat, cold air discharge side of the dielectric plug, dielectric discharge valve closed;
(2), slowly open the hot and cold medium inlet valve, heat, cold medium overflows from the bleed hole, then tighten the bleed plug, close the inlet valve.
3, when the water temperature 5 ~ 10 ℃, open the cooler medium inlet valve (Note: Avoid quickly open the inlet valve, due to the cooler water flows through the cooler is a large, long-term causes heat exchanger surface forming a layer of poor thermal conductivity, "cold layer"), and then open the valve and out of the heat medium, so that in the current state, then adjust their flow cooler medium, the heat medium is kept at optimum temperature.
4, if the cooler water side galvanic corrosion occurs, you can specify the location of the installation zinc rod.
5, before the adoption of dirty cooler medium, a filter device shall be provided.
6 is greater than the pressure of the pressure medium cooler cooler medium.
Fourth, maintenance and repair
1, after a long work surface will be cooler tube fouling resistance and flow resistance increases, so that the heat transfer performance is gradually reduced, as well as the requirements does not guarantee cooler. Obviously, the focus should be on maintenance to clean the dirt, here are a few clean-up methods:
(1)
a, the use of electric pigging tools. That is driven by a flexible shaft motor rotates, the shaft sleeve nylon brush or wire brush scrubbing rotation, cooler tube cooler works and use, and through a watertight cover the water column to the shaft around, so that timely wash out the loose dirt.
b, with a round tube with one end welded tube diameter similar in advance while rotating wire brush, dirt may be accumulating in the lumen of the tube, no dirt piled thick making it more difficult to promote this approach more often use, but labor-intensive, oil cooler leak loaders cooler inside.
(2), the use of high-pressure pump (pressure 10 ~ 20Mpa) high-pressure water spray to wash, better, is mainly used for pipe cleaning.
(3), using a sponge ball on the tubes for automatic cleaning. Depending on the scale layers of different hardness sponge balls, for special hard scale, can be a "band" diamond-shaped sponge ball. Its role is to use than the soft and elastic sponge balls into the tubes, compressed sponge balls are in contact with the tube wall, the wall of the ball and the relative movement, constant friction wall, the pellet was removed.
(4) Chemical Disposal Act:
a, the oil side of the cleaning solution can be used to reverse the cycle of trichlorethylene cleaning solution pressure is not greater than the rated working pressure. Cleaning time as the dirt on the circumstances, cooler cooling water, and then wash the introducer water until clean up out of the water.
b, by immersion of carbon tetrachloride. The solution is poured into the cooler, which lasted 15 to watch the color of the solution after 20 minutes, if the turbidity unbearable, then replaced with new re-soaking liquid until the color is similar effluent solution and clean up, and then repeatedly rinse with water, this should be cleaned good ventilation to avoid poisoning. This approach adapted to the oil clean.
2, the cooler's fault is mostly caused by the cooler tube. Due to corrosion, cavitation, wear leaving the wall thinning and perforation, but also due to the thermal expansion and contraction, vibration generated when the junction caused by fluid motion and other damage. After cooling pipe breakage two media will penetrate each other together, should be timely maintenance, which way are:
(1) identify the damaged pipe cooler, blocked at both ends of the pipe plugging. Plugs taper between 3 to 5 degrees, tube plugging material hardness should be less than or equal to the hardness of the tube, the total number of blocked tubes shall not exceed 10% of the total.
(2), remove the damaged pipe, replace the tube re-Expansion.
(3), the tube ends and tube plate junction leakage, should be re-Expansion. If severe corrosion, replace the tube bundle.
3, cooler winter disabled exhausted cavity medium should prevent cracking cooler.
4, coolers Disassembling and reassembling the following steps:
(1), close out of the oil, the water valve, the release medium retention, and the cooler is removed from the system.
(2), remove the lid and open backwater watershed cover, check the seals, cooler tube damage and fouling, etc.. If only plugs or replace cooler pipe can be carried out immediately, unplug the cooler if you need to bundle must be removed (large cooler unit can be vertical (fixed tube plate down) from the direction of the fixed tube sheet, and then use the lifting equipment Lift the casing to expose the bundle.
(3), the assembly carried by the reverse process of demolition, the general should be replaced with new seals.
(4), respectively, after the installation of air tightness test should first oil lateral water side, the test pressure should be greater than 1.2 times the actual working pressure.
V. Trouble Shooting
Heat transfer performance degradation
A failure and causes
(1) cooler water shortage;
(2) product gas chamber;
(3) heat exchange tube wall fouling increased flow resistance and heat resistance;
(4) Oil floats or cooler water of a mixture of oil and water;
(5) return manifold cover and cover flange leak;
(6) fixed, fixed aperture plate and tubes corrode and lose connections sealed.
2, Remedy
(1) failure and causes
① open large inlet valve;
② clean up blocked pipes, valves, filters or tubes;
(2) Remove the drain plug exhaust;
(3) the choice of appropriate methods to clean tubes inside and outside surfaces of dirt;
(4) ① replacement tubes;
② damaged pipe blocked with plugs (the number is not more than 10?);
(5) ① Tighten screw cap ends;
② Replace the gasket;
(6) to replace the tubes.
