Technical Proposal for Thermal Insulation of Large-Diameter Vertical Equipment

Technical Proposal for Thermal Insulation of Large-Diameter Vertical Equipment
1 Rock wool board material properties:
Density: 80 kg/m³
Thermal conductivity at ambient temperature: 0.038 W/(m·K)
Chloride ion content: ≤50 ppm
Volumetric moisture absorption rate: ≤1%
Combustion performance: Non-combustible; fire rating Class A1

2 Equipment insulation structure diagram

1) Prior to insulation work, equipment fabrication—including painting and hydrostatic or pneumatic testing—must be completed.
2) Impurities such as mud, grease, and dirt must be removed from the equipment's outer surface before insulation application. For areas requiring painting, insulation work must wait until the paint has dried.
3) For equipment supported by metal legs, the insulation layer shall begin at the lowest insulation point of the vessel; the insulation length extending beyond this point should exceed four times the insulation thickness.
4) Unless specific areas are designated as non-insulated (e.g., lifting trunnions, vent pipes), all metal parts and protrusions extending beyond the insulation layer shall be insulated. Insulation for flanges and valves on equipment branch pipes will be implemented on-site; this scope covers only the insulation of the equipment body itself.

3 Support ring design and process

1) The welding and installation of fixed support rings shall be performed by the equipment manufacturing unit (or department).
2) The spacing of the fixed support rings requires consultation with the purchaser, taking into account the vertical spacing of access platforms at the installation site; the preliminary design spacing is set at 3.5 m.
3) The fixed support rings provide the base support for the insulation material, while the external annular connecting plates provide fixing and support points for the metal outer cladding.
4) The spacing between anchor points connecting the fixed support ring to the equipment body is 1 m; the design load capacity for each anchor point is ≤30 kg of metal outer cladding weight.

4. Drain Plug Design and Fabrication
1) Design drainage/isolation spacers for the support rings; determine whether to place a spacer on every support ring or only at the bottom (where the spacer and drain plug are used).
2. Drainage and Runoff Design

5. Insulation Layer Structure and Fabrication
1) Before installing the first layer of insulation, bond 120mm-long insulation pins to the outer surfaces of the equipment shell and the top and bottom heads to secure the first layer.
2) Stagger the installation joints of the second insulation layer relative to those of the first layer, with a minimum stagger distance of 200mm (except at the top of the head); it is recommended to center the outer layer material over the joints of the inner layer.
3) Secure the second insulation layer overall by wrapping it with 1.2mm diameter stainless steel wire in a diagonal tensioning pattern anchored to the support rings, while simultaneously binding it circumferentially with 2mm diameter stainless steel wire.
4) Install floating rings for binding and securing at the top and bottom heads; the floating ring diameters shall be 0.5m and 1m, respectively.

6. Metal Outer Cladding Fixation
1) The metal outer cladding shall be made of 0.6mm thick 304 stainless steel sheet.
2) Before installing the metal outer cladding, construct a metal framework over the insulation layer to support and secure the metal sheets; the framework shall be fixed using flat steel bars connected to the outer ring plates of the support rings, with an average spacing of ≤1m between flat bars.
3) Secure the metal outer cladding using Ø5 stainless steel rivets, with an even distribution of fixation points along the circumference and length; the maximum spacing between rivets shall not exceed 200mm.
4) The minimum circumferential overlap for the metal protective layer shall be 50mm (or a combined interlocking joint may be used), and the minimum longitudinal overlap shall be 50mm. Stagger the joints of adjacent sheet rows by one-third of the sheet length.
5) The head cladding shall utilize a fan-shaped "orange-segment" structure, with joints staggered relative to the center.