Which parts of a chlor-alkali plant can be installed outdoors?

It shouldn’t be categorized by device; it should be categorized by equipment. Liquid chlorine packaging requires a factory building; electrolysis processes, as well as those that involve large-scale equipment, need such a building, while storage tanks can generally be placed outdoors.

Whether it’s possible to arrange things outdoors depends greatly on climate factors; places like Inner Mongolia and Jiangsu cannot be treated as a single category

The concept of no-factory design originated in the West, with the aim of shortening construction times so as to start production and generate profits as soon as possible; cost savings is not the main objective. For chlor-alkali plants, those that can be installed entirely in the open air include: all tank areas ； All facilities in the ion membrane boundary zone except the control room, electrolyzer cells, and rectifier cabinets ； Chlorohydrine treatment of all facilities except the pump machine ； Chlorine refrigerant: all facilities except compressors, storage tanks, and packaging areas ； Hydrochloric acid in all facilities except the operation room ； All facilities in the utility systems, except for the nitrogen compression machines, can be placed outdoors. Some equipment requires the installation of sunshades or rain shelters. These facilities often require steel or concrete structures to support or carry the equipment, so there is not much savings in terms of investment. The specific settings depend on local climate conditions such as temperature, precipitation, and wind and sand, as well as the special requirements of the equipment and the production process; each case must be handled individually, as there is no one-size-fits-all solution. In general, in addition to the indoor environment required by the equipment itself, the frequency of manual operation also needs to be taken into account; equipment that requires continuous manual supervision and pumps that need frequent inspection and maintenance are better suited to be installed indoors. In other cases, it is advisable to locate such installations outdoors as much as possible; this helps to **shorten the construction period**. The installation of equipment and pipelines can be accelerated by making use of large machinery such as cranes. Moreover, with a framework based on steel structures, construction and installation can proceed simultaneously with the manufacturing of the equipment. An entire installation can be completed in one year or even less, which represents a significant improvement compared to the previous situation where it took three to five years to complete such projects. This is just my personal opinion; please feel free to correct me.

After reading the tiger’s reply, I became much clearer-headed! The main issue is that all of our steel structures are suffering from severe corrosion, and the costs associated with anti-corrosion measures are very high. We’re unsure whether to leave everything exposed, allowing equipment and instruments to become damaged due to rain, or whether to install some kind of shelter or structure to provide protection. This is also an issue we need to pay attention to in our future devices. Perhaps the humidity in Chongqing is relatively high; in any case, corrosion in chlor-alkali industries is quite severe. However, the advantages of not building factories are also obvious. I wonder if anyone else faces similar challenges?

Try to avoid using steel structures; in areas with high humidity, even if steel structures are used, proper anti-corrosion measures must be taken for them. A good anti-corrosion roof will hold up fine for 3 to 5 years.

This post was last edited by *ou*ngzhe on 2009-11-4 at 23:54. 1. Locations where factory buildings are needed: warehouses, various control rooms, power distribution rooms, desalination stations, air compression stations, refrigeration stations, fire stations (due to fire safety requirements), salt storage areas, primary brine areas (with open-frame structures), electrolysis plants, dechlorination frameworks, frameworks for hydrogen chloride and waste gases, liquid chlorine plants, hydrochloric acid production frameworks, evaporation frameworks, etc. 2. Factories with steel structures can be used for: warehouses, salt storage areas, facilities for packaging liquid chlorine, and tank farm filling operations. 3. Equipment placed outdoors: In principle, any equipment that is not vulnerable to overheating or rain can be placed outdoors, such as various storage tanks, heat exchangers, pumps (with protective covers for the motors), etc. In chlor-alkali plants, equipment that is typically installed outdoors includes pure water storage tanks, acid and alkali storage tanks, storage tanks for nitrogen, air, and instrument air, strainers, circulation water pumps, brine tanks, preprocessors, chelation resin towers, as well as pumps for transporting brine, hydrochloric acid, pure water, and so on.

This largely depends on the continuity and stability of the production process operations, as well as on the measures taken for corrosion protection and safety of the equipment and pipelines. Below is an overview of the installation or layout of the various devices and equipment in our factory: 1. Primary brine processing stage: water distribution tanks, filters, clarification tanks, concentrated brine receiving tanks, and various pumps are placed outdoors; while salt storage areas and salt dissolving units are generally located in indoor facilities or steel structure buildings； 2. Dechlorination and electrolysis: Apart from the pure water tanks, brine tanks, and some surge tanks, everything is basically located indoors or in steel structure buildings ； 3. Chlorohydrogen treatment and waste gases: In addition to acid scrubbers, coolers, condensate collection tanks, as well as a high-level tank for concentrated sulfuric acid, a circulation tank, and a alkali dosing circulation tank, these components are generally installed in indoor factories or steel structure buildings ； 4. Synthesis of liquid chlorine and hydrogen chloride ； The refrigeration units, liquefaction units, as well as the packaging and storage facilities for the liquid chlorine process are all located indoors or in steel structure buildings. In the hydrogen chloride process, since the medium involved is highly hazardous, all of its main equipment is placed outdoors; however, the steel structures or buildings used for these facilities (such as chlorine and hydrogen buffer tanks, synthesis furnaces, coolers, hydrochloric acid storage tanks, etc.)

I suggest that where possible, steel frame structures should be avoided for building factories. In order to speed up the construction timeline for our various projects, steel frame structures were used for most of the factories; however, this leads to numerous problems once they are in operation, making things very inconvenient. Just brushing off rust and applying paint is already unbearable; if steel structures were to be protected against corrosion, the results might be better, but that would mean more work and higher costs.

Well, now our device is basically consistent with what was mentioned on the 7th floor. There’s no potential left to explore. In my opinion, the main issue relates to the facilities involving salt; it is best to use as little steel structure as possible in such systems, such as in the areas where raw salt is stored or near the salt storage ponds. In the resin tower area, especially in the chlorine processing section, there are many valves. Is it necessary to install a ceiling to reduce corrosion of these valves? We have experienced several disruptions in saltwater supply due to improper operation of the valves. By the way, I have a minor question: how is the pipe rack selected?

It seems that everyone is struggling with the corrosion prevention issue of steel structures. The anti-corrosion of steel structures relies crucially on initial rust removal and the application of an initial primer. As required, the steel structural components are mechanically rust-removed using methods such as sandblasting or fire treatment, with the aim of eliminating surface rust and exposing the steel surface completely. After that, putty is applied in two layers to achieve sealing; this layer serves as the base for the anti-corrosion coating. On the outside, there are three layers of primer followed by two layers of topcoat, with a fire-retardant coating applied as the outermost layer. The rust prevention problem that concerns us all often stems from the fact that proper attention was not given to the initial steps in the work. The main structure of the steel framework can be manufactured in a factory and then installed on-site, which does not affect the installation timeline of the facility. After the design is finalized, it can be produced simultaneously with the civil engineering work related to the foundation, allowing for installation to be completed at the same time as the installation of the equipment. The parts that need to be welded on-site are the details and local areas. After the steel structure construction is completed, any areas where the paint layer has been damaged must be repainted, using the same standards. The design and manufacturing of steel structures is an emerging field, and engineering technicians and managers in chemical plants should pay attention to this. They need to realize that steel structure buildings or structures do not result in significant cost savings; they merely help to shorten the construction time. The costs associated with corrosion prevention are also considerable, so one should not overlook these important aspects just because the savings seem small. Compared to steel structures, the construction period for concrete structures is much longer, but they possess the inherent advantage of being corrosion-resistant, which is why they are still widely used. Suggestion: Factories that are capable of carrying out strict anti-corrosion treatment can make extensive use of steel structures for factory buildings and framework structures; those that are not capable of doing so should avoid using them on a large scale. For plant frameworks that support equipment and are themselves exposed to high humidity, high salt levels, and highly corrosive gases, it is still recommended to use concrete structures, as in processes such as those involving high-purity acids, brackish water dechlorination, and primary brine treatment. The ductwork proposed by Box is, in fact, a type of structure; one can choose a steel structure or a steel-concrete structure – a purely concrete structure does not exist. For the resin tower modules in chlorine processing plants, due to the large number of pipelines and valves, it is recommended to install a quickly-assembled lightweight steel structure; the instruments used in chlorine processing are too delicate. Surely all of you sea friends have your own experiences, both successes and failures. Why not share them in the comments? We can complement each other and learn from one another to improve together.