Layout of liquefied hydrocarbon unloading cranes, unloading pumps, and compressors
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Hello, experts. I’m currently working on a project related to the unloading of ethylene (cold liquid) and propylene. I plan to locate the unloading pumps and compressors on the unloading skids (islands); there will be 4 skids for each of ethylene and propylene, with a distance of 6 meters between each pair of skids. Each loading pipe will be connected to one pump and one compressor. Does this violate the fire separation requirements specified in the petrochemical regulations? Does having a pump at each crane position constitute a centrally arranged set of pumps, given that the required distance between crane positions is greater than 10 meters?
Ethylene should be unloaded at low temperature; is propylene also unloaded at low temperature? The unloading pumps correspond one-to-one with the dip pipes, and can be placed together with the dip pipes, with a slightly increased spacing between them. The compressors can be shared; it is recommended to use the propylene compressor and the ethylene compressor together, placed in a separate location
Thank you. Propylene is at room temperature; is a distance of around 4 meters between the flexible hose and the pump sufficient? The 10-meter standard shouldn’t be necessary, right?
There is another question: Ethylene is a low-temperature liquefied hydrocarbon. What does clause 6.4.3, item 2 of the petrochemical regulations mean, which states that separate storage tanks should be provided for low-temperature liquefied hydrocarbons? Is it such that only one flexible hose can be used at the crane position, or can this hose be used exclusively for low-temperature liquefied hydrocarbons and not switched for other media? Or does it mean something else?
There is no strict requirement regarding the distance between the propylene flexible hose and the propylene-specific unloading pump; often, the unloading pump is placed on the unloading island.
First of all, the low-temperature unloading crane positions are definitely used separately and are theoretically not suitable for other purposes. Secondly, low-temperature transfer hoses require a separate transfer station and cannot share the same one as normal-temperature transfer hoses. Finally, there is a spacing requirement between low-temperature crane positions and normal-temperature crane positions, generally greater than 8 meters.
When two compressors are placed together, the spacing requirements from the transfer pipes need to be taken into account. I don’t think it’s appropriate. A compressor should be installed on the loading island; in this way, only the requirements related to the compressor and the transfer pipes need to be considered, with a distance of 8 meters between adjacent transfer stations being sufficient.
Ethylene is located on a separate island, which is equipped with an ethylene compressor and transfer pipes; no spacing requirements apply. Propylene is placed on another island, where the unloading pump (a bag pump is recommended) and the transfer pipes are designed together. The distance between the two flexibles is greater than 8 m. A single pump does not constitute a centrally arranged set of pumps; two or more pumps do
For each crane position for ethylene and propylene, separate pumps and compressors are installed; the distance between the two crane positions is set at 8 meters, and the safety distance from them to other crane positions is also not less than 8 meters.
This post was last edited by hnan on 2016-4-25 at 10:07. Hello, our company manufactures XCB sliding vane pumps that can be used as pumps for unloading chemical products.