Complete solutions - shelters
Due to the increasing role of in-line analysis in the process control of oil refining enterprises, and the need for constant high-quality maintenance of analytical equipment, an increasing number of chromatographs and analyzers are mounted in special large-sized cabinets or shelters with more powerful thermal insulation.
Shelter case with stainless steel base
Shelter case is made of fiberglass-reinforced two-layer plastic panels with a thickness of 20 to 80 mm with an inner layer of thermal insulation. In case of small shelters with overall dimensions HxWxH 2200x2000x1500 mm and moderate climate, panels with a thickness of 20 mm are used, when placing equipment in more severe conditions, as well as for large overall dimensions, for example HxWxD 2700x2500x3500 mm, it is recommended to use panels with a thickness of 40 and 80 mm.
Our company supplies shelters manufactured by Schramm GmbH, Germany. Shelter panels are made using a unique technology that gives the panels greater rigidity and strength. This feature makes it possible to mount circuit boards and various equipment directly to the threaded rivets embedded in the panel, avoiding additional profiles and amplifiers that take up a lot of space. It is worth noting that most of the similar cabinets made of plastic have significant drawbacks in terms of strength and equipment installation.
The base of the shelter serves as the supporting frame on which the shelter body is assembled, chromatographs and other heavy equipment are attached to it. The base of the shelter is made of a welded stainless profile with a cross section of 80 mm, forming a rigid frame. All internal cavities of the frame are foamed on a special machine to ensure high-quality thermal insulation.
Explosion-proof heaters are one of the most important elements of the shelter, since the viability of devices and systems located in the shelter depends on their uninterrupted and reliable operation throughout the cold period of the year. Heaters should have a large surface that provides a sufficient level of convection and radiation.
It is necessary to pre-calculate the power of the heaters taking into account the temperature difference inside and outside the shelter, wall thickness and thermal conductivity, as well as the presence of windows and holes. As a rule, one or more heaters with a power of 2 – 2.5 kW are installed in shelters. Preference is given to heaters with a capillary adjustable thermostat, with the type of protection “d” providing the best accuracy of maintaining the set temperature and maximum reliability of the device. In most cases, the thermostat is integrated with the heater body and is located below, close to the shelter floor, which ensures that the set temperature is maintained throughout the room. In some cases, the thermostat is placed remotely from the heater, near the most important area.
Sensors NKPV, MPC are designed to monitor the content of explosive or toxic substances in the atmosphere. The installation of sensors in shelters is mandatory in accordance with the Industrial Safety Rules. Sensors with explosion protection type “d” are extremely convenient for installation in shelters, providing not only control of the shelter’s working area, but also the ability to switch signaling devices and other equipment that notifies personnel about the appearance of a dangerous concentration of combustible and aggressive gases. In each specific case, the substance and the threshold of operation are selected, as well as the type of sensors.
To equip shelters, a large number of explosion-proof electrical equipment is required – these are fans, switches, sirens, terminal boxes, lamps, cable entries and other components. The reliability and safety of the whole system depends on the quality of this equipment.
When installing chromatographs, analyzers, and other equipment inside shelters, it is impossible to do without mounting profiles, trays and special fasteners, plates for mounting cable glands and other mounting accessories. In many cases, they are made according to individual drawings and require welding and the use of metalworking equipment.
When a constant supply of air to the shelter is required, for the purpose of efficient ventilation, duct heaters are installed in the ventilation ducts, designed to heat the atmospheric air while taking air from the surrounding atmosphere, which in the cold season is not possible in other cases due to low temperatures. The difficulty in installing a duct heater is associated with its high power consumption, and the need to install control cabinets. As a rule, duct heaters together with supply fans are installed in separate cabinets close to the main shelter, and are connected by ventilation ducts.
When equipment with very high heat dissipation is mounted, as well as equipment requiring accurate maintenance of the ambient temperature within 20-25 ° C, it is necessary to install an air conditioning system that provides room cooling during the period when the ambient temperatures are high. In cases when the ambient temperatures do not exceed + 30C for most of the year, as a rule, ordinary fans are used. For a number of devices and small cabinets that require additional cooling, vortex coolers are used to cool a specific shell, while the main room does not require additional cooling.
When installing chromatographs and other large-sized and complex devices, the main task becomes reliable mounting of the device, supply of impulse tubes and electric cables. For each case, a project is developed, and the final type of design is determined only after the installation of equipment. Particular attention is paid to sealing pneumatic connections to eliminate possible leaks that can lead to dangerous situations in a small enclosed space. In addition, when placing analyzers and sample preparation systems, special attention is paid to ease of maintenance and free access to all elements. Electrical cables are laid in trays and cable channels, which eliminates accidental damage and possible contact with liquids if they are present in analyzers and pneumatic lines. Also, at the request of the Customer, shelters can be equipped with separate compartments for mounting gas cylinders, necessary for the operation of analyzers. As a rule, balloon compartments are not heated, but if access to personnel is required in these compartments, they are equipped similarly to the main compartment.
To ensure the operation of analyzers and chromatographs, in addition to shelters and accessories, installation requires sample preparation systems and units, which are mounted in separate cabinets or boxes, as well as on panels inside the shelter. Therefore, the development of solutions for the installation of analytical equipment is a non-standard task, and requires a clear understanding, both from the developer and from the customer. At the same time, there are a number of mandatory requirements for ensuring the reliability and safety of equipment operation.
In many cases, the processes have high temperature and pressure, therefore, when sampling, it is necessary to install separate blocks for the primary preparation of the sample, providing a decrease in pressure and temperature to values acceptable by the analyzers. In addition, it is forbidden to introduce a sample under pressure above the required by the analyzer into the equipment room, which is determined by the safety requirements. In most cases, when the sample under normal conditions has a gas phase, and a decrease in pressure and, in some cases, evaporation of the sample is required, the primary preparation units are installed close to the sampling points. This is due to the fact that when transporting a sample under high pressure, the response time of the measuring system will be increased in proportion to the pressure. The higher the pressure, the more gas molecules per unit volume, and since the length and diameter of the sampling lines can be large, the sampling line can have a large volume, which, with a relatively small consumption of samples through the system, can increase the response time of the system to changes in the process up to several minutes and even hours, which is unacceptable. In addition to the blocks of primary sample preparation, in which primary filters, pressure regulators, safety valves are mounted, in the shelters with analyzers secondary components are also installed that bring the sample parameters to the required ones. Such components are rotameters, fine flow control valves, fine filters and a number of other devices. that with a relatively small consumption of samples through the system, it can increase the response time of the system to changes in the process up to several minutes and even hours, which is unacceptable. In addition to the blocks of primary sample preparation, in which primary filters, pressure regulators, safety valves are mounted, in the shelters with analyzers secondary components are also installed that bring the sample parameters to the required ones. Such components are rotameters, fine flow control valves, fine filters and a number of other devices. that with a relatively small consumption of samples through the system, it can increase the response time of the system to changes in the process up to several minutes and even hours, which is unacceptable. In addition to the blocks of primary sample preparation, in which primary filters, pressure regulators, safety valves are mounted, in the shelters with analyzers secondary components are also installed that bring the sample parameters to the required ones. Such components are rotameters, fine flow control valves, fine filters and a number of other devices.