Ina whakaarohia e te tangata te ngoikore o ngā taputapu ahumahi, ka whakaarohia e rātou he peera kua tawhito, he motuka kua wera, he hiri rānei kua mutu. E mōhio ana ngā kaihanga tipu he mea rerekē ake i tēnā. Ka taea e te papu te mea he mea hou, he tika te rahi, ā, ka kai ora tonu i a ia anō i roto i te tau kotahi nā te mea kotahi te tau kāore i te tino mārama i runga i te pepa raraunga.
Ko te ingoa o taua tau ko te NPSH. Ki te mea kāore anō kia mahi koe ki ngā papu, he rite tonu ki te hupa pīta. Engari ko te ariā kei muri e whakamārama ana i te nuinga o ngā hapa ngaro e kore ai e ara ake ngā kaiwhakahaere whare i te pō.
He aha rā te mea nei, ā, he aha te take e kino ai ngā taputapu utu nui ina hē te whakamahi?
NPSH i te reo Pākehā māmā
Upoko Momi Pai Kupenga e ine ana i te nui o te pēhanga o te wai i runga ake i tōna pūwāhi koropupū i te wā e tomo ana ki te papu. Ehara i te pāmahana. Ko te pēhanga. Ka taea e tetahi wai te koropupū i te pāmahana rūma mena ka heke te pēhanga, ā, koinā te mahanga.
E rua ngā tau o ia papu. Ko te NPSH e wātea ana (NPSHA) te mea e tukuna ana e te pūnaha ki te tomokanga papu. Ko te NPSH e hiahiatia ana (NPSHR) te mea e hiahiatia ana e te papu kia rere ai te wai me te kore e mura te wai i roto.
Ki te heke te Wātea ki raro iho i te Required, ka tīmata te wai ki te koropupū tika tonu i te impeller. He cavitation tēnā, ā, he tino kino.
He aha i whakahaere tonu ai te umanga i te Ture 3 ōrau mai i te tau 1932
Anei te wāhanga e miharo ana te tangata. Ehara te tau NPSHR i te nuinga o ngā pihi papu i te wāhi e mutu ai te mahi a te papu. Engari ko te wāhi kua heke kē te mahi. Nō te tau 1932 anō, i whakatau te Whare Waipēhi ki te hekenga o te upoko mā te 3 ōrau i te tere rere pumau hei whakamāramatanga mana, nā te mea koinei te huringa iti rawa ka taea e rātou te ine pono i runga i te tūnga whakamātautau.
I whakatakotoria te paerewa ahumahi tata ki te rau tau ki muri i runga i ngā mea ka taea te ine, kaua i runga i ngā mea e tiaki ana i te papu. I te wā i whakaputaina ai te NPSHR, kua roa kē te hinga o ngā mirumiru cavitation i roto i te impeller. Kāore anō kia tino whakaitihia te mahi kia kitea i runga i te ine.
Koia te take kāore ngā kaihoahoa mātau e mahi ana i te NPSHR. E mahi ana rātou me te tawhē. Ā, ko te rahi o taua tawhē te wāhi e puta ai ngā tautohetohe tūturu.
Te Kēmu Taha
Nā, e hia te nui o te tāpiri e hiahiatia ana e koe? Ko te whakautu pono: kei runga i te mea e papuhia ana e koe, te tere, me te nui o te pūngao e tākaihia ana ki roto i te momi. Ka hoatu e te aratohu a te Hydraulic Institute ngā ōwehenga whāinga mō ngā ahumahi rerekē. E ai ki tētahi whakarāpopototanga whakahoutanga hou o ANSI/HI 9.6.1, kua kapi te paerewa i ngā wāhanga mākete tekau, tae atu ki ngā papu tukatuka hinu, ngā papu tukatuka matū, te hiko, me te wai para.
He iti iho ngā taumata iti kua whakaputaina i tā te nuinga o te tangata e whakaaro ana. Mō ngā tono iti-pūngao pērā i ngā pourewa whakamatao me ngā papu waipara rino-maka, he iti noa iho ngā ōwehenga tawhē kua tūtohutia i runga ake i te 1, ko te tikanga he iti noa te NPSHA e eke ki te NPSHR. He angiangi te āhua. Mō ngā papu iti-pūngao, he pai noa iho.
He rerekē ngā mīhini kaha-mīhini. Kua whai tētahi rōpū mahi i roto i te Whare Hauora ngā tawhē e taunakitia ana e whā ngā whakarea o te NPSHR, arā, ko te ōwehenga NPSHA/NPSHR he 1 ki te 5. Ko te taumata teitei ake mō ngā papu e kawe ana i te kaha nekeneke tino kaha.
Ina Kāore e Rawa te Tapeke Anake
Ko te wāhanga whakararuraru tēnei. Ahakoa he nui te moni tāpiri, kāore e whakaora i a koe i ngā wā katoa. E whakaahua ana ngā tuhinga ahumahi i ngā papu whāngai poiha nui i hangaia ki te NPSHA, tata ki te rua te nui atu i te NPSHR kua whakaputaina, he nui atu i tā te pepa raraunga i tono ai.
Ko ngā impeller wāhanga tuatahi, i hangaia ki te maitai kore waikura CA6NM, i mau tonu mō te tau kotahi i mua i te whakakapinga nā te kino o te cavitation. E rua te nui o te tawhā i tonoa e te pukapuka ā-ringa, ā, ka ngaua tonutia e te papu ia ia anō i runga i te huringa ā-tau.
Ko ngā akoranga pēnei te take e whakahua ai ētahi kaihanga i tētahi whakaritenga rerekē e tuhia ana ko NPSH me te tuhinga roa. Kia tutuki taua uara, ka oati te kaihoko kāore he ngaronga o te mahi, kāore hoki he whakakapinga wāhanga i roto i te oma tau maha kua tautuhia o te mahi tonu. He rerekē te kī kāore te tau pepa raraunga e tiaki i a koe, engari mā tēnei.
He aha te tikanga o tēnei mēnā kei te hoko koe, kei te tautuhi, kei te hiahia noa rānei koe
Kāore koe e hiahia kia noho hei miihini taputapu hurihuri hei tango i tētahi mea whai hua mai i tēnei.
He mea whakamiharo te whai huatanga o ētahi mātāpono:
- Whakamahia te NPSHR hei papa, kaua hei ūnga. Mena kei te whakaatuhia e te tono he iti noa iho te NPSHA i runga ake i te NPSHR, he haki whero tēnā, ehara i te whakaae. Pātaihia mārama te ōwehenga tawhē.
- Pātai atu mō te pūngao momi. Ka rerekē rawa te whanonga o ngā papu e rua he ōrite ngā uara NPSHR i raro i te awhe kotahi. Me nui ake te wāhi e hiahiatia ana mō te kaha momi nui.
- Rapua he aratohu e pā ana ki te tono. He mea kino pea te tawhē e pai ana mō te pourewa whakamatao mō te whāngai poiha. He mea nui ake te wāhanga mākete i te ture whānui.
- Kia mataara ki te pūwāhi mahi. He kino ake te whanonga o te papu e oma ana i tawhiti atu i tōna taumata pai rawa atu i tā te pepa raraunga i matapae, ā, ko te NPSHR tonu ka ngokingoki haere ki runga i ngā pito rawa.
- Te tahua mō te tirotiro. Ka kitea te kino o te cavitation i runga i ngā vane impeller i mua noa atu i te kitenga i runga i ngā tau rere. Ki te tatari koe kia kī mai te ine pēhanga, he para kē te impeller.
Ehara tēnei i te mōhiotanga tauhou. Ko te rerekētanga tēnei i waenga i tētahi papu e oma pai ana mō te tekau tau, me tētahi e noho tonu ana hei tūemi raina i runga i te tahua tiaki. Ko te tau huna i runga i te pepa raraunga te mea e whakatau ana ko tēhea te mea ka whiwhi koe.