9: N ou cung dung, ploai, ctao, nguyon l y làm viec cua coc thiet bi van chuyen hon hop bo tong.

Cung dung: Hien nay o hau het cac cong trinh xay dung lon, hien dai, yeu cau su dung be tong voi khoi luong lon hoac o cac cong trinh xay dung mat bang san xuat chat hep, hoac o nhung noi co yeu cau chat luong be tong cao, nguoi ta khong dung cac may tron be tong tai cho ma thuong su dung be tong o cac nha may, tram tron de thi cong. Muon van chuyen be tong toi chan cong trinh va tu chan cong trinh den vi tri do hon hop be tong nguoi ta co nhieu phuong phap khac nhau, nhung phuong phap thuong dung va hieu qua nhat la dung oto cho be tong va cac loai bom be tong .v.v.

1. Oto cho be tong

Cau tao cua oto van chuyen be tong nhu hinh 9-6. Thung tron co dung tich 2.68m3, duoc dat tren khung nghieng 15o. Cac canh tron kieu vit dat trong thung tron de tron be tong khi thung tron quay theo chieu kim dong ho, con khi trung tron quay nguoc lai la de do be tong ra ngoai theo mang xa.

Oto cho be tong dung de tron va van chuyen be tong voi cu ly vai km toi vai chuc km tu tram tron be tong thuong pham toi noi tieu thu. Khi van chuyen betong o cu ly ngan, nguoi ta do be tong da tron vao thung (7580% dung tich thung) va cho quay voi van toc cham (34vg/ph) de dam bao be tong trong khi van chuyen khong bi phan tang va dong ket. Trong truong hop nay oto cho be tong chi lam nhiem vu van chuyen. Khi can cung cap be tong di xa thi nguoi ta do cot lieu kho chua tron vao trong thung (6070% dung tich thung) trong khi van chuyen, may tron dat tren xe se quay tron deu cot lieu voi nuoc thanh betong dong nhat (1012 vg/ph), toi noi lam viec chi can do ra dung ngay. Luc nay oto cho vua lam cong viec tron vua lam nhiem vu van chuyen

Oto cho be tong: 1- Thung tron; 2- Thiet bi nap va xa; 3- He thong cung cap nuoc; 4- Gia do thung tron; 5- He thong truyen dong; 6- He thong dieu khien; 7- Sat xi oto.

. 2. May bom betong

May bom be tong dung de van chuyen be tong co tinh linh dong (thuong co do sut >12cm) theo duong ong dan di xa toi 500m hoac len cao toi 70m. Muon bom xa hon va cao hon phai lap cac bom noi tiep. Bom betong con dung co hieu qua de bom vua xay dung.

Phan loai:

- Theo nguyen ly lam viec: lien tuc (kieu roto ong mem) va theo chu ky (kieu pittong);

- Theo kieu dan dong: co khi va thuy luc;

- Theo tinh co dong: tinh tai va co dong.

Cac loai bom thuong dung:

Hien nay o nuoc ta thuong dung ca may bom va xe bom betong kieu pittong thuy luc co hai xy lanh cong tac. May bom kieu tinh tai thuong dat tren gia truot de dang di chuyen trong pham vi cong truong; chung thuong dung tai cac cong truong lon. Cac xe bom co can bom phu hop khi thuong xuyen phai thay doi vi tri do be tong. Cac thong so chu yeu cua may bom betong la nang suat, do xa va chieu cao bom.

a. Bom be tong kieu ro to ong mem

Loai nay duoc dan dong thuy luc, cau tao bao gom: khoang bom 3 ben trong dat ong mem lam bang hon hop polyetylen va cao su nhan tao co mot dau noi voi thung chua - tron 7 con dau kia noi voi ong dan be tong 1 de chuyen be tong theo duong ong.

Khoang bom la mot vo hinh tru trong co bo tri roto 5 va hai con lan bang thep boc cao su 2. Truc ro to 4 duoc dan dong lam ro to quay. Khi roto quay mang hai con lan quay theo de len ong mem. He thong con lan va ong mem dong vai tro bom nen be tong theo ong mem. Khoang bom luon luon duy tri chan khong tu (0.0080.009)MPa nho vay ong phinh ra va hut be tong tu thung chua - tron vao ong mem.

Nguyen ly lam viec cua bom: Con lan chuyen dong quay hanh tinh quanh truc ro to, lan de len ong mem day be tong toi ong dan. Sau khi bi nen, ong lai tro lai vi tri ban dau do tinh dan hoi va co chan khong o trong khoang bom. Duoi ap luc cua khi quyen luong be tong duoc hut vao ong mem, con lan theo duong kinh khoang bom day hon hop vao duong ong dan. De lam sach duong ong nguoi ta cho nuoc vao thung chua, luc nay bom lam viec nhu mot bom nuoc.

Uu diem cua loai bom nay la ton it nang luong, dan dong thuy luc don gian, de cham soc bao duong.

Nhuoc diem: Co yeu cau cao ve thanh phan va do linh dong cua be tong, ap luc bom khong cao nen han che ve cu li cung nhu chieu cao bom, tuoi tho cua ong mem thap (khoang 23 nghin m3 be tong). Do vay su dung han che.

So do bom be tong kieu ro to ong mem

So do nguyen ly; 1- Duong ong day be tong; 2- Con lan; 3- Khoang bom; 4- Truc ro to; 5- Khoang ro to; 6- Duong ong hut be tong; 7- Thung chua-tron.

b. Bom be tong co van hinh chu S

Pho bien hien nay o nuoc ta su dung loai bom be tong hai pittong thuy luc co cua van hinh chu S (hinh 9.8) tren cac tram bom be tong co dinh va di dong, tren cac xe bom be tong. Van ong hinh chu S co nguyen ly lam viec nhu sau: van chu S duoc bo tri ngay trong khoang nap 1 cua bom, tam quay cua van trung voi tam cua ong dan be tong 4. Tai moi chu ky lam viec van duoc lac mot goc nhat dinh che kin duong ra 2 cua xylanh bom. Luc nay mot trong hai xylanh bom noi voi khoang nap 1, .be tong duoc chuyen theo ong dan bang thep duoc ghep noi voi nhau nho khoa dac biet chuyen dung.

* Uu, nhuoc diem:

- Uu diem: chinh cua loai van nay la su thay doi huong chuyen dong cua dong hon hop khi hut va day la it nhat.

Nhuoc diem: o moi chu ky bom phai can mot luong cong suat de dao mot khoi luong kha lon (khoi hon hop be tong va khoi van hinh chu S); phai thang luc quan tinh va luc ma sat tai vung lam kin cua van voi mieng xy lanh bom va cho noi van voi duong ong dan.

* Luu y: Khi bac ong can dat thang va bang vi neu dat theo duong cong hoac len cao thi ton that nang luong va do hao mon cua ong dan cua may bom se lon hon. Sau khi dung xong, can phai rua sach may bom va duong ong dan de tranh xi mang dong lai lam tang luc can va lam hong may. Thong thuong hay dung cach do nuoc vao may bom va cho chay de rua sach bom va ong dan.

Trong nhung nam gan day o nuoc ta pho bien dung xe bom be tong co dong co can bom, co kha nang vuon xa va len cao de do betong len toi 60m. Cac loai xe nay trang bi he thong chan do nen do on dinh cao khi lam viec.

Nang suat cua may bom be tong duoc tinh theo cong thuc:

Q = 60FSnknktg , m3/h

trong do: F- tiet dien ngang cua pittong, m2;

S- hanh trinh cua pittong, m;

n- so lan bom trong 1 phut cua pittong;

kn- he so dien day hon hop cua pittong, kn= 0.80.9;

ktg- he so su dung theo thoi gian.

So do may bom be tong hai pittong thuy luc co van chu S

b- So do nguyen ly lam viec cua van chu S.; 1- Khoang nap; 2- Pittong bom; 3- Van chu S; 4- Ong dan be tong.