Design and construction of an improved vending machine for food items in Mulago hospital.
Abstract
Mulago hospital is the biggest referral hospital in Uganda registering the biggest number of
patients on a daily basis. Food is supplied to the hospital by both the government and private
vendors. The private vendors supply both cooked food like matooke, rice, posho with sauce
and other food items like samosas, chapati, boiled eggs and others. However, the vendors lack
improved vending machines for such food items that keep them warm for customers. This
project was carried out to develop an improved vending machine of food items at Mulago
hospital. In this project a rechargeable battery is used to supply current to the heating element
which in turn induces the heating that is used in food warming. The project focused on how the
food elements can be kept warm at ambient temperatures depending on the customer needs.
Surveys and other data collection methods were employed to assess the customer needs and
target specifications were set to suit the needs. Different software was used to develop the
design for the food warmer and set dimensions for the food warmer. Different calculations
were also carried out to determine the amount of heat and the range of temperatures to which
the food items are to be kept. The fabrication process involving welding, cutting, drilling and
binding was carried out for the production of a mobile food warmer.
Different tests were carried out in the evaluation of the performance of the food warmer. For a
given period of time different temperatures were recorded for different food items in the
experiments carried out. The temperature of a chapati rose from 250C to 400C in five minutes,
the temperature of the samosa rose from 250C to 400C in 6 minutes the boiled egg was not
uniformly warmed however it took 7 minutes for its temperature to rise from 250C to 450C.
The vending machine had a capacity of 50 chapatti, 30 samosas, 20 boiled eggs and 20 half
cakes. A 12V battery, needed to be recharged depending on how often the food warmer was
switched on to warm the food. However on average it would work for 8 hours before
recharging.
The food vending machine therefore satisfied the customer needs in mobility, portability,
keeping the food items clean and safe from contamination and at the ambient temperatures
required for consuming. However, the capacity was lacking depending on the number of
customers in the hospital that want the food items therefore, further modifications were
recommended to increase on the capacity