If the Treasurer finds that any person, who is or may be, liable for taxes upon personal property, the taxable situs of which was in the City on tax day, intends to depart from the City or to remove therefrom personal property, which is, or may be, liable for taxation, or intends to conceal himself or his property, or intends to do any other act tending to prejudice, or to render wholly or partly ineffectual, the proceedings to collect the tax, unless proceedings therefor cannot be brought without delay, he shall cause notice of his finding to be given such person, together with a demand for the immediate payment of the tax. Thereupon, the tax shall become immediately due and payable and the Treasurer shall have and exercise all the powers granted by law to township and city treasurers for the collection thereof. If the exact amount of any such tax has not, at the time of such finding, been determined because the same has not been spread upon the tax roll, the Treasurer shall estimate the amount of the tax upon such personal property and the estimate shall be presumed to be the amount of tax upon such property which, together with other taxes which have accrued thereon, shall become payable as hereinabove provided. The tax so estimated by the Treasurer shall, upon the giving of the notice herein provided, become a lien upon the property liable for the tax. The lien shall be of the same type and legal effect as the lien upon personal property provided in Section 12.18 of this chapter. If the estimate of the Treasurer is in excess of the amount of tax spread against such property upon the tax roll, he shall refund the excess upon the demand of the person from whom it was collected or his legal representative. If such person furnishes evidence, satisfactory to the Treasurer, by bond or otherwise, that he will duly pay the tax or taxes to which the Treasurer's finding relates, then such tax or taxes shall not be payable prior to the time otherwise fixed for payment thereof.